diff mbox

[v4,2/5] ARM:sunxi:drivers:input Add support for A10/A20 PS2

Message ID 1421417021-3247-3-git-send-email-vishnupatekar0510@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

vishnupatekar Jan. 16, 2015, 2:03 p.m. UTC
Signed-off-by: VishnuPatekar <vishnupatekar0510@gmail.com>
---
 drivers/input/serio/Kconfig     |   11 ++
 drivers/input/serio/Makefile    |    1 +
 drivers/input/serio/sun4i-ps2.c |  330 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 342 insertions(+)
 create mode 100644 drivers/input/serio/sun4i-ps2.c

Comments

Dmitry Torokhov Jan. 17, 2015, 10:25 p.m. UTC | #1
Hi Vishnu,

On Fri, Jan 16, 2015 at 07:33:38PM +0530, Vishnu Patekar wrote:
> Signed-off-by: VishnuPatekar <vishnupatekar0510@gmail.com>
> ---
>  drivers/input/serio/Kconfig     |   11 ++
>  drivers/input/serio/Makefile    |    1 +
>  drivers/input/serio/sun4i-ps2.c |  330 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 342 insertions(+)
>  create mode 100644 drivers/input/serio/sun4i-ps2.c
> 
> diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig
> index bc2d474..964afc5 100644
> --- a/drivers/input/serio/Kconfig
> +++ b/drivers/input/serio/Kconfig
> @@ -281,4 +281,15 @@ config HYPERV_KEYBOARD
>  	  To compile this driver as a module, choose M here: the module will
>  	  be called hyperv_keyboard.
>  
> +config SERIO_SUN4I_PS2
> +	tristate "Allwinner A10 PS/2 controller support"
> +	default n
> +	depends on ARCH_SUNXI || COMPILE_TEST
> +	help
> +	  This selects support for the PS/2 Host Controller on
> +	  Allwinner A10.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called sun4i-ps2.
> +
>  endif
> diff --git a/drivers/input/serio/Makefile b/drivers/input/serio/Makefile
> index 815d874..c600089 100644
> --- a/drivers/input/serio/Makefile
> +++ b/drivers/input/serio/Makefile
> @@ -29,3 +29,4 @@ obj-$(CONFIG_SERIO_ARC_PS2)	+= arc_ps2.o
>  obj-$(CONFIG_SERIO_APBPS2)	+= apbps2.o
>  obj-$(CONFIG_SERIO_OLPC_APSP)	+= olpc_apsp.o
>  obj-$(CONFIG_HYPERV_KEYBOARD)	+= hyperv-keyboard.o
> +obj-$(CONFIG_SERIO_SUN4I_PS2)	+= sun4i-ps2.o
> diff --git a/drivers/input/serio/sun4i-ps2.c b/drivers/input/serio/sun4i-ps2.c
> new file mode 100644
> index 0000000..06b3fef
> --- /dev/null
> +++ b/drivers/input/serio/sun4i-ps2.c
> @@ -0,0 +1,330 @@
> +/*
> + *	Driver for Allwinner A10 PS2 host controller
> + *
> + *	Author: Vishnu Patekar <vishnupatekar0510@gmail.com>
> + *		Aaron.maoye <leafy.myeh@newbietech.com>
> + *
> + *
> + */
> +
> +#include <linux/module.h>
> +#include <linux/serio.h>
> +#include <linux/interrupt.h>
> +#include <linux/errno.h>
> +#include <linux/slab.h>
> +#include <linux/list.h>
> +#include <linux/io.h>
> +#include <linux/of_address.h>
> +#include <linux/of_device.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_platform.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +
> +#define DRIVER_NAME		"sun4i-ps2"
> +
> +/* register offset definitions */
> +#define PS2_REG_GCTL		0x00	/*  PS2 Module Global Control Reg */
> +#define PS2_REG_DATA		0x04	/*  PS2 Module Data Reg		*/
> +#define PS2_REG_LCTL		0x08	/*  PS2 Module Line Control Reg */
> +#define PS2_REG_LSTS		0x0C	/*  PS2 Module Line Status Reg	*/
> +#define PS2_REG_FCTL		0x10	/*  PS2 Module FIFO Control Reg */
> +#define PS2_REG_FSTS		0x14	/*  PS2 Module FIFO Status Reg	*/
> +#define PS2_REG_CLKDR		0x18	/*  PS2 Module Clock Divider Reg*/
> +
> +/*  PS2 GLOBAL CONTROL REGISTER PS2_GCTL */
> +#define PS2_GCTL_INTFLAG	BIT(4)
> +#define PS2_GCTL_INTEN		BIT(3)
> +#define PS2_GCTL_RESET		BIT(2)
> +#define PS2_GCTL_MASTER		BIT(1)
> +#define PS2_GCTL_BUSEN		BIT(0)
> +
> +/* PS2 LINE CONTROL REGISTER */
> +#define PS2_LCTL_NOACK		BIT(18)
> +#define PS2_LCTL_TXDTOEN	BIT(8)
> +#define PS2_LCTL_STOPERREN	BIT(3)
> +#define PS2_LCTL_ACKERREN	BIT(2)
> +#define PS2_LCTL_PARERREN	BIT(1)
> +#define PS2_LCTL_RXDTOEN	BIT(0)
> +
> +/* PS2 LINE STATUS REGISTER */
> +#define PS2_LSTS_TXTDO		BIT(8)
> +#define PS2_LSTS_STOPERR	BIT(3)
> +#define PS2_LSTS_ACKERR		BIT(2)
> +#define PS2_LSTS_PARERR		BIT(1)
> +#define PS2_LSTS_RXTDO		BIT(0)
> +
> +#define PS2_LINE_ERROR_BIT \
> +	(PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR | \
> +	PS2_LSTS_PARERR | PS2_LSTS_RXTDO)
> +
> +/* PS2 FIFO CONTROL REGISTER */
> +#define PS2_FCTL_TXRST		BIT(17)
> +#define PS2_FCTL_RXRST		BIT(16)
> +#define PS2_FCTL_TXUFIEN	BIT(10)
> +#define PS2_FCTL_TXOFIEN	BIT(9)
> +#define PS2_FCTL_TXRDYIEN	BIT(8)
> +#define PS2_FCTL_RXUFIEN	BIT(2)
> +#define PS2_FCTL_RXOFIEN	BIT(1)
> +#define PS2_FCTL_RXRDYIEN	BIT(0)
> +
> +/* PS2 FIFO STATUS REGISTER */
> +#define PS2_FSTS_TXUF		BIT(10)
> +#define PS2_FSTS_TXOF		BIT(9)
> +#define PS2_FSTS_TXRDY		BIT(8)
> +#define PS2_FSTS_RXUF		BIT(2)
> +#define PS2_FSTS_RXOF		BIT(1)
> +#define PS2_FSTS_RXRDY		BIT(0)
> +
> +#define PS2_FIFO_ERROR_BIT \
> +	(PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_RXUF | PS2_FSTS_RXOF)
> +
> +#define PS2_SAMPLE_CLK		1000000
> +#define PS2_SCLK		125000
> +
> +struct sun4i_ps2data {
> +	struct serio *serio;
> +	struct device *dev;
> +
> +	/* IO mapping base */
> +	void __iomem	*reg_base;
> +
> +	/* clock management */
> +	struct clk	*clk;
> +
> +	/* irq */
> +	spinlock_t	lock;
> +	int		irq;
> +};
> +
> +/*********************/
> +/* Interrupt handler */
> +/*********************/
> +static irqreturn_t sun4i_ps2_interrupt(int irq, void *dev_id)
> +{
> +	struct sun4i_ps2data *drvdata = dev_id;
> +	u32 intr_status;
> +	u32 fifo_status;
> +	unsigned char byte;
> +	unsigned int rxflags = 0;
> +	u32 rval;
> +
> +	spin_lock(&drvdata->lock);
> +
> +	/* Get the PS/2 interrupts and clear them */
> +	intr_status  = readl(drvdata->reg_base + PS2_REG_LSTS);
> +	fifo_status  = readl(drvdata->reg_base + PS2_REG_FSTS);
> +
> +	/*Check Line Status Register*/
> +	if (intr_status & PS2_LINE_ERROR_BIT) {
> +		rxflags = (intr_status & PS2_LINE_ERROR_BIT) ? SERIO_FRAME : 0;
> +		rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_PARITY : 0;
> +		rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_TIMEOUT : 0;
> +
> +		rval = PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR |
> +			PS2_LSTS_PARERR | PS2_LSTS_RXTDO;
> +		writel(rval, drvdata->reg_base + PS2_REG_LSTS);
> +	}
> +
> +	/*Check FIFO Status Register*/
> +	if (fifo_status & PS2_FIFO_ERROR_BIT) {
> +		rval = PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_TXRDY |
> +			PS2_FSTS_RXUF | PS2_FSTS_RXOF | PS2_FSTS_RXRDY;
> +		writel(rval, drvdata->reg_base + PS2_REG_FSTS);
> +	}
> +
> +	rval = (fifo_status >> 16) & 0x3;
> +	while (rval--) {
> +		byte = readl(drvdata->reg_base + PS2_REG_DATA) & 0xff;
> +		serio_interrupt(drvdata->serio, byte, rxflags);
> +	}
> +
> +	writel(intr_status, drvdata->reg_base + PS2_REG_LSTS);
> +	writel(fifo_status, drvdata->reg_base + PS2_REG_FSTS);
> +
> +	spin_unlock(&drvdata->lock);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +
> +static int sun4i_ps2_open(struct serio *pserio)
> +{
> +	struct sun4i_ps2data *drvdata = pserio->port_data;
> +	u32 src_clk = 0;
> +	u32 clk_scdf;
> +	u32 clk_pcdf;
> +	u32 rval;
> +	unsigned long flags;
> +
> +	/*Set Line Control And Enable Interrupt*/
> +	rval = PS2_LCTL_STOPERREN | PS2_LCTL_ACKERREN
> +		| PS2_LCTL_PARERREN | PS2_LCTL_RXDTOEN;
> +	writel(rval, drvdata->reg_base + PS2_REG_LCTL);
> +
> +	/*Reset FIFO*/
> +	rval = PS2_FCTL_TXRST | PS2_FCTL_RXRST | PS2_FCTL_TXUFIEN
> +		| PS2_FCTL_TXOFIEN | PS2_FCTL_RXUFIEN
> +		| PS2_FCTL_RXOFIEN | PS2_FCTL_RXRDYIEN;
> +
> +	writel(rval, drvdata->reg_base + PS2_REG_FCTL);
> +
> +	src_clk = clk_get_rate(drvdata->clk);
> +	/*Set Clock Divider Register*/
> +	clk_scdf = src_clk / PS2_SAMPLE_CLK - 1;
> +	clk_pcdf = PS2_SAMPLE_CLK / PS2_SCLK - 1;
> +	rval = (clk_scdf<<8) | clk_pcdf;
> +	writel(rval, drvdata->reg_base + PS2_REG_CLKDR);
> +
> +
> +	/*Set Global Control Register*/
> +	rval = PS2_GCTL_RESET | PS2_GCTL_INTEN | PS2_GCTL_MASTER
> +		| PS2_GCTL_BUSEN;
> +
> +	spin_lock_irqsave(&drvdata->lock, flags);
> +	writel(rval, drvdata->reg_base + PS2_REG_GCTL);
> +	spin_unlock_irqrestore(&drvdata->lock, flags);
> +
> +	return 0;
> +}
> +
> +static void sun4i_ps2_close(struct serio *pserio)
> +{
> +	struct sun4i_ps2data *drvdata = pserio->port_data;
> +
> +	synchronize_irq(drvdata->irq);

synchronize_irq() on it's own is not very useful. You also need to shut
off interrupts on the chip (I suppose by clearing PS2_GCTL_INTEN?)
before calling synchronize_irq.

> +}
> +
> +static int sun4i_ps2_write(struct serio *pserio, unsigned char val)
> +{
> +	unsigned long expire = jiffies + msecs_to_jiffies(10000);
> +	struct sun4i_ps2data *drvdata;
> +
> +	drvdata = (struct sun4i_ps2data *)pserio->port_data;
> +
> +	do {
> +		if (readl(drvdata->reg_base + PS2_REG_FSTS) & PS2_FSTS_TXRDY) {
> +			writel(val, drvdata->reg_base + PS2_REG_DATA);
> +			return 0;
> +		}
> +	} while (time_before(jiffies, expire));
> +
> +	return SERIO_TIMEOUT;
> +}
> +
> +static int sun4i_ps2_probe(struct platform_device *pdev)
> +{
> +	struct resource *res; /* IO mem resources */
> +	struct sun4i_ps2data *drvdata;
> +	struct serio *serio;
> +	struct device *dev = &pdev->dev;
> +	unsigned int irq;
> +	int error;
> +
> +	drvdata = devm_kzalloc(dev, sizeof(struct sun4i_ps2data), GFP_KERNEL);
> +	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
> +	if (!drvdata || !serio) {
> +		error = -ENOMEM;
> +		goto err_free_mem;
> +	}
> +
> +	spin_lock_init(&drvdata->lock);
> +
> +	/* IO */
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	drvdata->reg_base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(drvdata->reg_base)) {
> +		dev_err(dev, "failed to map registers\n");
> +		error = PTR_ERR(drvdata->reg_base);
> +		goto err_free_mem;
> +	}
> +
> +	drvdata->clk = devm_clk_get(dev, NULL);
> +	if (IS_ERR(drvdata->clk)) {
> +		error = PTR_ERR(drvdata->clk);
> +		dev_err(dev, "couldn't get clock %d\n", error);
> +		goto err_free_mem;
> +	}
> +
> +	error = clk_prepare_enable(drvdata->clk);
> +	if (error) {
> +		dev_err(dev, "failed to enable clock %d\n", error);
> +		goto err_free_mem;
> +	}
> +
> +	serio->id.type = SERIO_8042;
> +	serio->write = sun4i_ps2_write;
> +	serio->open = sun4i_ps2_open;
> +	serio->close = sun4i_ps2_close;
> +	serio->port_data = drvdata;
> +	serio->dev.parent = dev;
> +	strlcpy(serio->name, dev_name(dev), sizeof(serio->name));
> +	strlcpy(serio->phys, dev_name(dev), sizeof(serio->phys));
> +
> +	/* Get IRQ for the device */
> +	irq = platform_get_irq(pdev, 0);
> +	if (!irq) {
> +		dev_err(dev, "no IRQ found\n");
> +		error = -ENXIO;
> +		goto error_disable_clk;
> +	}
> +
> +	drvdata->irq = irq;
> +	drvdata->serio = serio;
> +	drvdata->dev = dev;
> +	error = devm_request_threaded_irq(dev, drvdata->irq,
> +		sun4i_ps2_interrupt, NULL, 0, DRIVER_NAME, drvdata);
> +
> +	if (error) {
> +		dev_err(drvdata->dev, "Interrupt alloc failed %d:error:%d\n",
> +			drvdata->irq, error);
> +		goto error_disable_clk;
> +	}
> +
> +	serio_register_port(serio);
> +	platform_set_drvdata(pdev, drvdata);
> +
> +	return 0;	/* success */
> +
> +error_disable_clk:
> +	clk_disable_unprepare(drvdata->clk);
> +
> +err_free_mem:
> +	kfree(serio);
> +	return error;
> +}
> +
> +static int sun4i_ps2_remove(struct platform_device *pdev)
> +{
> +	struct sun4i_ps2data *drvdata = platform_get_drvdata(pdev);
> +
> +	serio_unregister_port(drvdata->serio);
> +
> +	if (!IS_ERR(drvdata->clk))
> +		clk_disable_unprepare(drvdata->clk);
> +	kfree(drvdata->serio);

Serio is refcounted, you do not free it after its has been registered.
Overall I'd rather you did not use devm* interfaces here since you are
forced to mix managed and manually freed resources.

> +
> +	return 0;
> +}
> +
> +static const struct of_device_id sun4i_ps2_match[] = {
> +	{ .compatible = "allwinner,sun4i-a10-ps2", },
> +	{ },
> +};
> +
> +MODULE_DEVICE_TABLE(of, sun4i_ps2_match);
> +
> +static struct platform_driver sun4i_ps2_driver = {
> +	.probe		= sun4i_ps2_probe,
> +	.remove		= sun4i_ps2_remove,
> +	.driver = {
> +		.name = DRIVER_NAME,
> +		.of_match_table = sun4i_ps2_match,
> +	},
> +};
> +module_platform_driver(sun4i_ps2_driver);
> +
> +MODULE_AUTHOR("Vishnu Patekar <vishnupatekar0510@gmail.com>");
> +MODULE_AUTHOR("Aaron.maoye <leafy.myeh@newbietech.com>");
> +MODULE_DESCRIPTION("Allwinner A10/Sun4i PS/2 driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 1.7.9.5
> 

Thanks.
vishnupatekar Jan. 19, 2015, 6:07 a.m. UTC | #2
Hello Dmitry,

Thank you for review comments. Please see in-lined.

On Sun, Jan 18, 2015 at 3:55 AM, Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
> Hi Vishnu,
>
> On Fri, Jan 16, 2015 at 07:33:38PM +0530, Vishnu Patekar wrote:
>> Signed-off-by: VishnuPatekar <vishnupatekar0510@gmail.com>
>> ---
>>  drivers/input/serio/Kconfig     |   11 ++
>>  drivers/input/serio/Makefile    |    1 +
>>  drivers/input/serio/sun4i-ps2.c |  330 +++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 342 insertions(+)
>>  create mode 100644 drivers/input/serio/sun4i-ps2.c
>>
>> diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig
>> index bc2d474..964afc5 100644
>> --- a/drivers/input/serio/Kconfig
>> +++ b/drivers/input/serio/Kconfig
>> @@ -281,4 +281,15 @@ config HYPERV_KEYBOARD
>>         To compile this driver as a module, choose M here: the module will
>>         be called hyperv_keyboard.
>>
>> +config SERIO_SUN4I_PS2
>> +     tristate "Allwinner A10 PS/2 controller support"
>> +     default n
>> +     depends on ARCH_SUNXI || COMPILE_TEST
>> +     help
>> +       This selects support for the PS/2 Host Controller on
>> +       Allwinner A10.
>> +
>> +       To compile this driver as a module, choose M here: the
>> +       module will be called sun4i-ps2.
>> +
>>  endif
>> diff --git a/drivers/input/serio/Makefile b/drivers/input/serio/Makefile
>> index 815d874..c600089 100644
>> --- a/drivers/input/serio/Makefile
>> +++ b/drivers/input/serio/Makefile
>> @@ -29,3 +29,4 @@ obj-$(CONFIG_SERIO_ARC_PS2) += arc_ps2.o
>>  obj-$(CONFIG_SERIO_APBPS2)   += apbps2.o
>>  obj-$(CONFIG_SERIO_OLPC_APSP)        += olpc_apsp.o
>>  obj-$(CONFIG_HYPERV_KEYBOARD)        += hyperv-keyboard.o
>> +obj-$(CONFIG_SERIO_SUN4I_PS2)        += sun4i-ps2.o
>> diff --git a/drivers/input/serio/sun4i-ps2.c b/drivers/input/serio/sun4i-ps2.c
>> new file mode 100644
>> index 0000000..06b3fef
>> --- /dev/null
>> +++ b/drivers/input/serio/sun4i-ps2.c
>> @@ -0,0 +1,330 @@
>> +/*
>> + *   Driver for Allwinner A10 PS2 host controller
>> + *
>> + *   Author: Vishnu Patekar <vishnupatekar0510@gmail.com>
>> + *           Aaron.maoye <leafy.myeh@newbietech.com>
>> + *
>> + *
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/serio.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/errno.h>
>> +#include <linux/slab.h>
>> +#include <linux/list.h>
>> +#include <linux/io.h>
>> +#include <linux/of_address.h>
>> +#include <linux/of_device.h>
>> +#include <linux/of_irq.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/clk.h>
>> +#include <linux/delay.h>
>> +
>> +#define DRIVER_NAME          "sun4i-ps2"
>> +
>> +/* register offset definitions */
>> +#define PS2_REG_GCTL         0x00    /*  PS2 Module Global Control Reg */
>> +#define PS2_REG_DATA         0x04    /*  PS2 Module Data Reg         */
>> +#define PS2_REG_LCTL         0x08    /*  PS2 Module Line Control Reg */
>> +#define PS2_REG_LSTS         0x0C    /*  PS2 Module Line Status Reg  */
>> +#define PS2_REG_FCTL         0x10    /*  PS2 Module FIFO Control Reg */
>> +#define PS2_REG_FSTS         0x14    /*  PS2 Module FIFO Status Reg  */
>> +#define PS2_REG_CLKDR                0x18    /*  PS2 Module Clock Divider Reg*/
>> +
>> +/*  PS2 GLOBAL CONTROL REGISTER PS2_GCTL */
>> +#define PS2_GCTL_INTFLAG     BIT(4)
>> +#define PS2_GCTL_INTEN               BIT(3)
>> +#define PS2_GCTL_RESET               BIT(2)
>> +#define PS2_GCTL_MASTER              BIT(1)
>> +#define PS2_GCTL_BUSEN               BIT(0)
>> +
>> +/* PS2 LINE CONTROL REGISTER */
>> +#define PS2_LCTL_NOACK               BIT(18)
>> +#define PS2_LCTL_TXDTOEN     BIT(8)
>> +#define PS2_LCTL_STOPERREN   BIT(3)
>> +#define PS2_LCTL_ACKERREN    BIT(2)
>> +#define PS2_LCTL_PARERREN    BIT(1)
>> +#define PS2_LCTL_RXDTOEN     BIT(0)
>> +
>> +/* PS2 LINE STATUS REGISTER */
>> +#define PS2_LSTS_TXTDO               BIT(8)
>> +#define PS2_LSTS_STOPERR     BIT(3)
>> +#define PS2_LSTS_ACKERR              BIT(2)
>> +#define PS2_LSTS_PARERR              BIT(1)
>> +#define PS2_LSTS_RXTDO               BIT(0)
>> +
>> +#define PS2_LINE_ERROR_BIT \
>> +     (PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR | \
>> +     PS2_LSTS_PARERR | PS2_LSTS_RXTDO)
>> +
>> +/* PS2 FIFO CONTROL REGISTER */
>> +#define PS2_FCTL_TXRST               BIT(17)
>> +#define PS2_FCTL_RXRST               BIT(16)
>> +#define PS2_FCTL_TXUFIEN     BIT(10)
>> +#define PS2_FCTL_TXOFIEN     BIT(9)
>> +#define PS2_FCTL_TXRDYIEN    BIT(8)
>> +#define PS2_FCTL_RXUFIEN     BIT(2)
>> +#define PS2_FCTL_RXOFIEN     BIT(1)
>> +#define PS2_FCTL_RXRDYIEN    BIT(0)
>> +
>> +/* PS2 FIFO STATUS REGISTER */
>> +#define PS2_FSTS_TXUF                BIT(10)
>> +#define PS2_FSTS_TXOF                BIT(9)
>> +#define PS2_FSTS_TXRDY               BIT(8)
>> +#define PS2_FSTS_RXUF                BIT(2)
>> +#define PS2_FSTS_RXOF                BIT(1)
>> +#define PS2_FSTS_RXRDY               BIT(0)
>> +
>> +#define PS2_FIFO_ERROR_BIT \
>> +     (PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_RXUF | PS2_FSTS_RXOF)
>> +
>> +#define PS2_SAMPLE_CLK               1000000
>> +#define PS2_SCLK             125000
>> +
>> +struct sun4i_ps2data {
>> +     struct serio *serio;
>> +     struct device *dev;
>> +
>> +     /* IO mapping base */
>> +     void __iomem    *reg_base;
>> +
>> +     /* clock management */
>> +     struct clk      *clk;
>> +
>> +     /* irq */
>> +     spinlock_t      lock;
>> +     int             irq;
>> +};
>> +
>> +/*********************/
>> +/* Interrupt handler */
>> +/*********************/
>> +static irqreturn_t sun4i_ps2_interrupt(int irq, void *dev_id)
>> +{
>> +     struct sun4i_ps2data *drvdata = dev_id;
>> +     u32 intr_status;
>> +     u32 fifo_status;
>> +     unsigned char byte;
>> +     unsigned int rxflags = 0;
>> +     u32 rval;
>> +
>> +     spin_lock(&drvdata->lock);
>> +
>> +     /* Get the PS/2 interrupts and clear them */
>> +     intr_status  = readl(drvdata->reg_base + PS2_REG_LSTS);
>> +     fifo_status  = readl(drvdata->reg_base + PS2_REG_FSTS);
>> +
>> +     /*Check Line Status Register*/
>> +     if (intr_status & PS2_LINE_ERROR_BIT) {
>> +             rxflags = (intr_status & PS2_LINE_ERROR_BIT) ? SERIO_FRAME : 0;
>> +             rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_PARITY : 0;
>> +             rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_TIMEOUT : 0;
>> +
>> +             rval = PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR |
>> +                     PS2_LSTS_PARERR | PS2_LSTS_RXTDO;
>> +             writel(rval, drvdata->reg_base + PS2_REG_LSTS);
>> +     }
>> +
>> +     /*Check FIFO Status Register*/
>> +     if (fifo_status & PS2_FIFO_ERROR_BIT) {
>> +             rval = PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_TXRDY |
>> +                     PS2_FSTS_RXUF | PS2_FSTS_RXOF | PS2_FSTS_RXRDY;
>> +             writel(rval, drvdata->reg_base + PS2_REG_FSTS);
>> +     }
>> +
>> +     rval = (fifo_status >> 16) & 0x3;
>> +     while (rval--) {
>> +             byte = readl(drvdata->reg_base + PS2_REG_DATA) & 0xff;
>> +             serio_interrupt(drvdata->serio, byte, rxflags);
>> +     }
>> +
>> +     writel(intr_status, drvdata->reg_base + PS2_REG_LSTS);
>> +     writel(fifo_status, drvdata->reg_base + PS2_REG_FSTS);
>> +
>> +     spin_unlock(&drvdata->lock);
>> +
>> +     return IRQ_HANDLED;
>> +}
>> +
>> +
>> +static int sun4i_ps2_open(struct serio *pserio)
>> +{
>> +     struct sun4i_ps2data *drvdata = pserio->port_data;
>> +     u32 src_clk = 0;
>> +     u32 clk_scdf;
>> +     u32 clk_pcdf;
>> +     u32 rval;
>> +     unsigned long flags;
>> +
>> +     /*Set Line Control And Enable Interrupt*/
>> +     rval = PS2_LCTL_STOPERREN | PS2_LCTL_ACKERREN
>> +             | PS2_LCTL_PARERREN | PS2_LCTL_RXDTOEN;
>> +     writel(rval, drvdata->reg_base + PS2_REG_LCTL);
>> +
>> +     /*Reset FIFO*/
>> +     rval = PS2_FCTL_TXRST | PS2_FCTL_RXRST | PS2_FCTL_TXUFIEN
>> +             | PS2_FCTL_TXOFIEN | PS2_FCTL_RXUFIEN
>> +             | PS2_FCTL_RXOFIEN | PS2_FCTL_RXRDYIEN;
>> +
>> +     writel(rval, drvdata->reg_base + PS2_REG_FCTL);
>> +
>> +     src_clk = clk_get_rate(drvdata->clk);
>> +     /*Set Clock Divider Register*/
>> +     clk_scdf = src_clk / PS2_SAMPLE_CLK - 1;
>> +     clk_pcdf = PS2_SAMPLE_CLK / PS2_SCLK - 1;
>> +     rval = (clk_scdf<<8) | clk_pcdf;
>> +     writel(rval, drvdata->reg_base + PS2_REG_CLKDR);
>> +
>> +
>> +     /*Set Global Control Register*/
>> +     rval = PS2_GCTL_RESET | PS2_GCTL_INTEN | PS2_GCTL_MASTER
>> +             | PS2_GCTL_BUSEN;
>> +
>> +     spin_lock_irqsave(&drvdata->lock, flags);
>> +     writel(rval, drvdata->reg_base + PS2_REG_GCTL);
>> +     spin_unlock_irqrestore(&drvdata->lock, flags);
>> +
>> +     return 0;
>> +}
>> +
>> +static void sun4i_ps2_close(struct serio *pserio)
>> +{
>> +     struct sun4i_ps2data *drvdata = pserio->port_data;
>> +
>> +     synchronize_irq(drvdata->irq);
>
> synchronize_irq() on it's own is not very useful. You also need to shut
> off interrupts on the chip (I suppose by clearing PS2_GCTL_INTEN?)
> before calling synchronize_irq.
Okie, I'll do it. Yes, clearing PS2_GCTL_INTEN will shut off the interrupts.
>
>> +}
>> +
>> +static int sun4i_ps2_write(struct serio *pserio, unsigned char val)
>> +{
>> +     unsigned long expire = jiffies + msecs_to_jiffies(10000);
>> +     struct sun4i_ps2data *drvdata;
>> +
>> +     drvdata = (struct sun4i_ps2data *)pserio->port_data;
>> +
>> +     do {
>> +             if (readl(drvdata->reg_base + PS2_REG_FSTS) & PS2_FSTS_TXRDY) {
>> +                     writel(val, drvdata->reg_base + PS2_REG_DATA);
>> +                     return 0;
>> +             }
>> +     } while (time_before(jiffies, expire));
>> +
>> +     return SERIO_TIMEOUT;
>> +}
>> +
>> +static int sun4i_ps2_probe(struct platform_device *pdev)
>> +{
>> +     struct resource *res; /* IO mem resources */
>> +     struct sun4i_ps2data *drvdata;
>> +     struct serio *serio;
>> +     struct device *dev = &pdev->dev;
>> +     unsigned int irq;
>> +     int error;
>> +
>> +     drvdata = devm_kzalloc(dev, sizeof(struct sun4i_ps2data), GFP_KERNEL);
>> +     serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
>> +     if (!drvdata || !serio) {
>> +             error = -ENOMEM;
>> +             goto err_free_mem;
>> +     }
>> +
>> +     spin_lock_init(&drvdata->lock);
>> +
>> +     /* IO */
>> +     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +     drvdata->reg_base = devm_ioremap_resource(dev, res);
>> +     if (IS_ERR(drvdata->reg_base)) {
>> +             dev_err(dev, "failed to map registers\n");
>> +             error = PTR_ERR(drvdata->reg_base);
>> +             goto err_free_mem;
>> +     }
>> +
>> +     drvdata->clk = devm_clk_get(dev, NULL);
>> +     if (IS_ERR(drvdata->clk)) {
>> +             error = PTR_ERR(drvdata->clk);
>> +             dev_err(dev, "couldn't get clock %d\n", error);
>> +             goto err_free_mem;
>> +     }
>> +
>> +     error = clk_prepare_enable(drvdata->clk);
>> +     if (error) {
>> +             dev_err(dev, "failed to enable clock %d\n", error);
>> +             goto err_free_mem;
>> +     }
>> +
>> +     serio->id.type = SERIO_8042;
>> +     serio->write = sun4i_ps2_write;
>> +     serio->open = sun4i_ps2_open;
>> +     serio->close = sun4i_ps2_close;
>> +     serio->port_data = drvdata;
>> +     serio->dev.parent = dev;
>> +     strlcpy(serio->name, dev_name(dev), sizeof(serio->name));
>> +     strlcpy(serio->phys, dev_name(dev), sizeof(serio->phys));
>> +
>> +     /* Get IRQ for the device */
>> +     irq = platform_get_irq(pdev, 0);
>> +     if (!irq) {
>> +             dev_err(dev, "no IRQ found\n");
>> +             error = -ENXIO;
>> +             goto error_disable_clk;
>> +     }
>> +
>> +     drvdata->irq = irq;
>> +     drvdata->serio = serio;
>> +     drvdata->dev = dev;
>> +     error = devm_request_threaded_irq(dev, drvdata->irq,
>> +             sun4i_ps2_interrupt, NULL, 0, DRIVER_NAME, drvdata);
>> +
>> +     if (error) {
>> +             dev_err(drvdata->dev, "Interrupt alloc failed %d:error:%d\n",
>> +                     drvdata->irq, error);
>> +             goto error_disable_clk;
>> +     }
>> +
>> +     serio_register_port(serio);
>> +     platform_set_drvdata(pdev, drvdata);
>> +
>> +     return 0;       /* success */
>> +
>> +error_disable_clk:
>> +     clk_disable_unprepare(drvdata->clk);
>> +
>> +err_free_mem:
>> +     kfree(serio);
>> +     return error;
>> +}
>> +
>> +static int sun4i_ps2_remove(struct platform_device *pdev)
>> +{
>> +     struct sun4i_ps2data *drvdata = platform_get_drvdata(pdev);
>> +
>> +     serio_unregister_port(drvdata->serio);
>> +
>> +     if (!IS_ERR(drvdata->clk))
>> +             clk_disable_unprepare(drvdata->clk);
>> +     kfree(drvdata->serio);
>
> Serio is refcounted, you do not free it after its has been registered.
> Overall I'd rather you did not use devm* interfaces here since you are
> forced to mix managed and manually freed resources.
Okie, No need to free serio here.
If serio is not manually freed here, It is not freeing anything else manually.

do you still feel I should not use devm* interfaces here?
>
>> +
>> +     return 0;
>> +}
>> +
>> +static const struct of_device_id sun4i_ps2_match[] = {
>> +     { .compatible = "allwinner,sun4i-a10-ps2", },
>> +     { },
>> +};
>> +
>> +MODULE_DEVICE_TABLE(of, sun4i_ps2_match);
>> +
>> +static struct platform_driver sun4i_ps2_driver = {
>> +     .probe          = sun4i_ps2_probe,
>> +     .remove         = sun4i_ps2_remove,
>> +     .driver = {
>> +             .name = DRIVER_NAME,
>> +             .of_match_table = sun4i_ps2_match,
>> +     },
>> +};
>> +module_platform_driver(sun4i_ps2_driver);
>> +
>> +MODULE_AUTHOR("Vishnu Patekar <vishnupatekar0510@gmail.com>");
>> +MODULE_AUTHOR("Aaron.maoye <leafy.myeh@newbietech.com>");
>> +MODULE_DESCRIPTION("Allwinner A10/Sun4i PS/2 driver");
>> +MODULE_LICENSE("GPL v2");
>> --
>> 1.7.9.5
>>
>
> Thanks.
>
> --
> Dmitry
Dmitry Torokhov Jan. 20, 2015, 12:35 a.m. UTC | #3
On Mon, Jan 19, 2015 at 11:37:38AM +0530, Vishnu Patekar wrote:
> Hello Dmitry,
> 
> Thank you for review comments. Please see in-lined.
> 
> On Sun, Jan 18, 2015 at 3:55 AM, Dmitry Torokhov
> <dmitry.torokhov@gmail.com> wrote:
> > Hi Vishnu,
> >
> > On Fri, Jan 16, 2015 at 07:33:38PM +0530, Vishnu Patekar wrote:
> >> Signed-off-by: VishnuPatekar <vishnupatekar0510@gmail.com>
> >> ---
> >>  drivers/input/serio/Kconfig     |   11 ++
> >>  drivers/input/serio/Makefile    |    1 +
> >>  drivers/input/serio/sun4i-ps2.c |  330 +++++++++++++++++++++++++++++++++++++++
> >>  3 files changed, 342 insertions(+)
> >>  create mode 100644 drivers/input/serio/sun4i-ps2.c
> >>
> >> diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig
> >> index bc2d474..964afc5 100644
> >> --- a/drivers/input/serio/Kconfig
> >> +++ b/drivers/input/serio/Kconfig
> >> @@ -281,4 +281,15 @@ config HYPERV_KEYBOARD
> >>         To compile this driver as a module, choose M here: the module will
> >>         be called hyperv_keyboard.
> >>
> >> +config SERIO_SUN4I_PS2
> >> +     tristate "Allwinner A10 PS/2 controller support"
> >> +     default n
> >> +     depends on ARCH_SUNXI || COMPILE_TEST
> >> +     help
> >> +       This selects support for the PS/2 Host Controller on
> >> +       Allwinner A10.
> >> +
> >> +       To compile this driver as a module, choose M here: the
> >> +       module will be called sun4i-ps2.
> >> +
> >>  endif
> >> diff --git a/drivers/input/serio/Makefile b/drivers/input/serio/Makefile
> >> index 815d874..c600089 100644
> >> --- a/drivers/input/serio/Makefile
> >> +++ b/drivers/input/serio/Makefile
> >> @@ -29,3 +29,4 @@ obj-$(CONFIG_SERIO_ARC_PS2) += arc_ps2.o
> >>  obj-$(CONFIG_SERIO_APBPS2)   += apbps2.o
> >>  obj-$(CONFIG_SERIO_OLPC_APSP)        += olpc_apsp.o
> >>  obj-$(CONFIG_HYPERV_KEYBOARD)        += hyperv-keyboard.o
> >> +obj-$(CONFIG_SERIO_SUN4I_PS2)        += sun4i-ps2.o
> >> diff --git a/drivers/input/serio/sun4i-ps2.c b/drivers/input/serio/sun4i-ps2.c
> >> new file mode 100644
> >> index 0000000..06b3fef
> >> --- /dev/null
> >> +++ b/drivers/input/serio/sun4i-ps2.c
> >> @@ -0,0 +1,330 @@
> >> +/*
> >> + *   Driver for Allwinner A10 PS2 host controller
> >> + *
> >> + *   Author: Vishnu Patekar <vishnupatekar0510@gmail.com>
> >> + *           Aaron.maoye <leafy.myeh@newbietech.com>
> >> + *
> >> + *
> >> + */
> >> +
> >> +#include <linux/module.h>
> >> +#include <linux/serio.h>
> >> +#include <linux/interrupt.h>
> >> +#include <linux/errno.h>
> >> +#include <linux/slab.h>
> >> +#include <linux/list.h>
> >> +#include <linux/io.h>
> >> +#include <linux/of_address.h>
> >> +#include <linux/of_device.h>
> >> +#include <linux/of_irq.h>
> >> +#include <linux/of_platform.h>
> >> +#include <linux/clk.h>
> >> +#include <linux/delay.h>
> >> +
> >> +#define DRIVER_NAME          "sun4i-ps2"
> >> +
> >> +/* register offset definitions */
> >> +#define PS2_REG_GCTL         0x00    /*  PS2 Module Global Control Reg */
> >> +#define PS2_REG_DATA         0x04    /*  PS2 Module Data Reg         */
> >> +#define PS2_REG_LCTL         0x08    /*  PS2 Module Line Control Reg */
> >> +#define PS2_REG_LSTS         0x0C    /*  PS2 Module Line Status Reg  */
> >> +#define PS2_REG_FCTL         0x10    /*  PS2 Module FIFO Control Reg */
> >> +#define PS2_REG_FSTS         0x14    /*  PS2 Module FIFO Status Reg  */
> >> +#define PS2_REG_CLKDR                0x18    /*  PS2 Module Clock Divider Reg*/
> >> +
> >> +/*  PS2 GLOBAL CONTROL REGISTER PS2_GCTL */
> >> +#define PS2_GCTL_INTFLAG     BIT(4)
> >> +#define PS2_GCTL_INTEN               BIT(3)
> >> +#define PS2_GCTL_RESET               BIT(2)
> >> +#define PS2_GCTL_MASTER              BIT(1)
> >> +#define PS2_GCTL_BUSEN               BIT(0)
> >> +
> >> +/* PS2 LINE CONTROL REGISTER */
> >> +#define PS2_LCTL_NOACK               BIT(18)
> >> +#define PS2_LCTL_TXDTOEN     BIT(8)
> >> +#define PS2_LCTL_STOPERREN   BIT(3)
> >> +#define PS2_LCTL_ACKERREN    BIT(2)
> >> +#define PS2_LCTL_PARERREN    BIT(1)
> >> +#define PS2_LCTL_RXDTOEN     BIT(0)
> >> +
> >> +/* PS2 LINE STATUS REGISTER */
> >> +#define PS2_LSTS_TXTDO               BIT(8)
> >> +#define PS2_LSTS_STOPERR     BIT(3)
> >> +#define PS2_LSTS_ACKERR              BIT(2)
> >> +#define PS2_LSTS_PARERR              BIT(1)
> >> +#define PS2_LSTS_RXTDO               BIT(0)
> >> +
> >> +#define PS2_LINE_ERROR_BIT \
> >> +     (PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR | \
> >> +     PS2_LSTS_PARERR | PS2_LSTS_RXTDO)
> >> +
> >> +/* PS2 FIFO CONTROL REGISTER */
> >> +#define PS2_FCTL_TXRST               BIT(17)
> >> +#define PS2_FCTL_RXRST               BIT(16)
> >> +#define PS2_FCTL_TXUFIEN     BIT(10)
> >> +#define PS2_FCTL_TXOFIEN     BIT(9)
> >> +#define PS2_FCTL_TXRDYIEN    BIT(8)
> >> +#define PS2_FCTL_RXUFIEN     BIT(2)
> >> +#define PS2_FCTL_RXOFIEN     BIT(1)
> >> +#define PS2_FCTL_RXRDYIEN    BIT(0)
> >> +
> >> +/* PS2 FIFO STATUS REGISTER */
> >> +#define PS2_FSTS_TXUF                BIT(10)
> >> +#define PS2_FSTS_TXOF                BIT(9)
> >> +#define PS2_FSTS_TXRDY               BIT(8)
> >> +#define PS2_FSTS_RXUF                BIT(2)
> >> +#define PS2_FSTS_RXOF                BIT(1)
> >> +#define PS2_FSTS_RXRDY               BIT(0)
> >> +
> >> +#define PS2_FIFO_ERROR_BIT \
> >> +     (PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_RXUF | PS2_FSTS_RXOF)
> >> +
> >> +#define PS2_SAMPLE_CLK               1000000
> >> +#define PS2_SCLK             125000
> >> +
> >> +struct sun4i_ps2data {
> >> +     struct serio *serio;
> >> +     struct device *dev;
> >> +
> >> +     /* IO mapping base */
> >> +     void __iomem    *reg_base;
> >> +
> >> +     /* clock management */
> >> +     struct clk      *clk;
> >> +
> >> +     /* irq */
> >> +     spinlock_t      lock;
> >> +     int             irq;
> >> +};
> >> +
> >> +/*********************/
> >> +/* Interrupt handler */
> >> +/*********************/
> >> +static irqreturn_t sun4i_ps2_interrupt(int irq, void *dev_id)
> >> +{
> >> +     struct sun4i_ps2data *drvdata = dev_id;
> >> +     u32 intr_status;
> >> +     u32 fifo_status;
> >> +     unsigned char byte;
> >> +     unsigned int rxflags = 0;
> >> +     u32 rval;
> >> +
> >> +     spin_lock(&drvdata->lock);
> >> +
> >> +     /* Get the PS/2 interrupts and clear them */
> >> +     intr_status  = readl(drvdata->reg_base + PS2_REG_LSTS);
> >> +     fifo_status  = readl(drvdata->reg_base + PS2_REG_FSTS);
> >> +
> >> +     /*Check Line Status Register*/
> >> +     if (intr_status & PS2_LINE_ERROR_BIT) {
> >> +             rxflags = (intr_status & PS2_LINE_ERROR_BIT) ? SERIO_FRAME : 0;
> >> +             rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_PARITY : 0;
> >> +             rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_TIMEOUT : 0;
> >> +
> >> +             rval = PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR |
> >> +                     PS2_LSTS_PARERR | PS2_LSTS_RXTDO;
> >> +             writel(rval, drvdata->reg_base + PS2_REG_LSTS);
> >> +     }
> >> +
> >> +     /*Check FIFO Status Register*/
> >> +     if (fifo_status & PS2_FIFO_ERROR_BIT) {
> >> +             rval = PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_TXRDY |
> >> +                     PS2_FSTS_RXUF | PS2_FSTS_RXOF | PS2_FSTS_RXRDY;
> >> +             writel(rval, drvdata->reg_base + PS2_REG_FSTS);
> >> +     }
> >> +
> >> +     rval = (fifo_status >> 16) & 0x3;
> >> +     while (rval--) {
> >> +             byte = readl(drvdata->reg_base + PS2_REG_DATA) & 0xff;
> >> +             serio_interrupt(drvdata->serio, byte, rxflags);
> >> +     }
> >> +
> >> +     writel(intr_status, drvdata->reg_base + PS2_REG_LSTS);
> >> +     writel(fifo_status, drvdata->reg_base + PS2_REG_FSTS);
> >> +
> >> +     spin_unlock(&drvdata->lock);
> >> +
> >> +     return IRQ_HANDLED;
> >> +}
> >> +
> >> +
> >> +static int sun4i_ps2_open(struct serio *pserio)
> >> +{
> >> +     struct sun4i_ps2data *drvdata = pserio->port_data;
> >> +     u32 src_clk = 0;
> >> +     u32 clk_scdf;
> >> +     u32 clk_pcdf;
> >> +     u32 rval;
> >> +     unsigned long flags;
> >> +
> >> +     /*Set Line Control And Enable Interrupt*/
> >> +     rval = PS2_LCTL_STOPERREN | PS2_LCTL_ACKERREN
> >> +             | PS2_LCTL_PARERREN | PS2_LCTL_RXDTOEN;
> >> +     writel(rval, drvdata->reg_base + PS2_REG_LCTL);
> >> +
> >> +     /*Reset FIFO*/
> >> +     rval = PS2_FCTL_TXRST | PS2_FCTL_RXRST | PS2_FCTL_TXUFIEN
> >> +             | PS2_FCTL_TXOFIEN | PS2_FCTL_RXUFIEN
> >> +             | PS2_FCTL_RXOFIEN | PS2_FCTL_RXRDYIEN;
> >> +
> >> +     writel(rval, drvdata->reg_base + PS2_REG_FCTL);
> >> +
> >> +     src_clk = clk_get_rate(drvdata->clk);
> >> +     /*Set Clock Divider Register*/
> >> +     clk_scdf = src_clk / PS2_SAMPLE_CLK - 1;
> >> +     clk_pcdf = PS2_SAMPLE_CLK / PS2_SCLK - 1;
> >> +     rval = (clk_scdf<<8) | clk_pcdf;
> >> +     writel(rval, drvdata->reg_base + PS2_REG_CLKDR);
> >> +
> >> +
> >> +     /*Set Global Control Register*/
> >> +     rval = PS2_GCTL_RESET | PS2_GCTL_INTEN | PS2_GCTL_MASTER
> >> +             | PS2_GCTL_BUSEN;
> >> +
> >> +     spin_lock_irqsave(&drvdata->lock, flags);
> >> +     writel(rval, drvdata->reg_base + PS2_REG_GCTL);
> >> +     spin_unlock_irqrestore(&drvdata->lock, flags);
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static void sun4i_ps2_close(struct serio *pserio)
> >> +{
> >> +     struct sun4i_ps2data *drvdata = pserio->port_data;
> >> +
> >> +     synchronize_irq(drvdata->irq);
> >
> > synchronize_irq() on it's own is not very useful. You also need to shut
> > off interrupts on the chip (I suppose by clearing PS2_GCTL_INTEN?)
> > before calling synchronize_irq.
> Okie, I'll do it. Yes, clearing PS2_GCTL_INTEN will shut off the interrupts.

Please also do shut off interrupts on the chip before requesting IRQ.

> >
> >> +}
> >> +
> >> +static int sun4i_ps2_write(struct serio *pserio, unsigned char val)
> >> +{
> >> +     unsigned long expire = jiffies + msecs_to_jiffies(10000);
> >> +     struct sun4i_ps2data *drvdata;
> >> +
> >> +     drvdata = (struct sun4i_ps2data *)pserio->port_data;
> >> +
> >> +     do {
> >> +             if (readl(drvdata->reg_base + PS2_REG_FSTS) & PS2_FSTS_TXRDY) {
> >> +                     writel(val, drvdata->reg_base + PS2_REG_DATA);
> >> +                     return 0;
> >> +             }
> >> +     } while (time_before(jiffies, expire));
> >> +
> >> +     return SERIO_TIMEOUT;
> >> +}
> >> +
> >> +static int sun4i_ps2_probe(struct platform_device *pdev)
> >> +{
> >> +     struct resource *res; /* IO mem resources */
> >> +     struct sun4i_ps2data *drvdata;
> >> +     struct serio *serio;
> >> +     struct device *dev = &pdev->dev;
> >> +     unsigned int irq;
> >> +     int error;
> >> +
> >> +     drvdata = devm_kzalloc(dev, sizeof(struct sun4i_ps2data), GFP_KERNEL);
> >> +     serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
> >> +     if (!drvdata || !serio) {
> >> +             error = -ENOMEM;
> >> +             goto err_free_mem;
> >> +     }
> >> +
> >> +     spin_lock_init(&drvdata->lock);
> >> +
> >> +     /* IO */
> >> +     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >> +     drvdata->reg_base = devm_ioremap_resource(dev, res);
> >> +     if (IS_ERR(drvdata->reg_base)) {
> >> +             dev_err(dev, "failed to map registers\n");
> >> +             error = PTR_ERR(drvdata->reg_base);
> >> +             goto err_free_mem;
> >> +     }
> >> +
> >> +     drvdata->clk = devm_clk_get(dev, NULL);
> >> +     if (IS_ERR(drvdata->clk)) {
> >> +             error = PTR_ERR(drvdata->clk);
> >> +             dev_err(dev, "couldn't get clock %d\n", error);
> >> +             goto err_free_mem;
> >> +     }
> >> +
> >> +     error = clk_prepare_enable(drvdata->clk);
> >> +     if (error) {
> >> +             dev_err(dev, "failed to enable clock %d\n", error);
> >> +             goto err_free_mem;
> >> +     }
> >> +
> >> +     serio->id.type = SERIO_8042;
> >> +     serio->write = sun4i_ps2_write;
> >> +     serio->open = sun4i_ps2_open;
> >> +     serio->close = sun4i_ps2_close;
> >> +     serio->port_data = drvdata;
> >> +     serio->dev.parent = dev;
> >> +     strlcpy(serio->name, dev_name(dev), sizeof(serio->name));
> >> +     strlcpy(serio->phys, dev_name(dev), sizeof(serio->phys));
> >> +
> >> +     /* Get IRQ for the device */
> >> +     irq = platform_get_irq(pdev, 0);
> >> +     if (!irq) {
> >> +             dev_err(dev, "no IRQ found\n");
> >> +             error = -ENXIO;
> >> +             goto error_disable_clk;
> >> +     }
> >> +
> >> +     drvdata->irq = irq;
> >> +     drvdata->serio = serio;
> >> +     drvdata->dev = dev;
> >> +     error = devm_request_threaded_irq(dev, drvdata->irq,
> >> +             sun4i_ps2_interrupt, NULL, 0, DRIVER_NAME, drvdata);
> >> +
> >> +     if (error) {
> >> +             dev_err(drvdata->dev, "Interrupt alloc failed %d:error:%d\n",
> >> +                     drvdata->irq, error);
> >> +             goto error_disable_clk;
> >> +     }
> >> +
> >> +     serio_register_port(serio);
> >> +     platform_set_drvdata(pdev, drvdata);
> >> +
> >> +     return 0;       /* success */
> >> +
> >> +error_disable_clk:
> >> +     clk_disable_unprepare(drvdata->clk);
> >> +
> >> +err_free_mem:
> >> +     kfree(serio);
> >> +     return error;
> >> +}
> >> +
> >> +static int sun4i_ps2_remove(struct platform_device *pdev)
> >> +{
> >> +     struct sun4i_ps2data *drvdata = platform_get_drvdata(pdev);
> >> +
> >> +     serio_unregister_port(drvdata->serio);
> >> +
> >> +     if (!IS_ERR(drvdata->clk))
> >> +             clk_disable_unprepare(drvdata->clk);
> >> +     kfree(drvdata->serio);
> >
> > Serio is refcounted, you do not free it after its has been registered.
> > Overall I'd rather you did not use devm* interfaces here since you are
> > forced to mix managed and manually freed resources.
> Okie, No need to free serio here.
> If serio is not manually freed here, It is not freeing anything else manually.

You are still unregistering the port manually and disabling the clock manually.
> 
> do you still feel I should not use devm* interfaces here?

Yes, because of above. My rule of thumb - when using devm* API there should not
be remove() at all.

BTW, if one added devm_* API to serio, similar to devm* in input core, I'd take
such patch.

Thanks.
vishnupatekar Jan. 21, 2015, 11:22 a.m. UTC | #4
Hello Dmitry,

On Tue, Jan 20, 2015 at 6:05 AM, Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
> On Mon, Jan 19, 2015 at 11:37:38AM +0530, Vishnu Patekar wrote:
>> Hello Dmitry,
>>
>> Thank you for review comments. Please see in-lined.
>>
>> On Sun, Jan 18, 2015 at 3:55 AM, Dmitry Torokhov
>> <dmitry.torokhov@gmail.com> wrote:
>> > Hi Vishnu,
>> >
>> > On Fri, Jan 16, 2015 at 07:33:38PM +0530, Vishnu Patekar wrote:
>> >> Signed-off-by: VishnuPatekar <vishnupatekar0510@gmail.com>
>> >> ---
>> >>  drivers/input/serio/Kconfig     |   11 ++
>> >>  drivers/input/serio/Makefile    |    1 +
>> >>  drivers/input/serio/sun4i-ps2.c |  330 +++++++++++++++++++++++++++++++++++++++
>> >>  3 files changed, 342 insertions(+)
>> >>  create mode 100644 drivers/input/serio/sun4i-ps2.c
>> >>
>> >> diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig
>> >> index bc2d474..964afc5 100644
>> >> --- a/drivers/input/serio/Kconfig
>> >> +++ b/drivers/input/serio/Kconfig
>> >> @@ -281,4 +281,15 @@ config HYPERV_KEYBOARD
>> >>         To compile this driver as a module, choose M here: the module will
>> >>         be called hyperv_keyboard.
>> >>
>> >> +config SERIO_SUN4I_PS2
>> >> +     tristate "Allwinner A10 PS/2 controller support"
>> >> +     default n
>> >> +     depends on ARCH_SUNXI || COMPILE_TEST
>> >> +     help
>> >> +       This selects support for the PS/2 Host Controller on
>> >> +       Allwinner A10.
>> >> +
>> >> +       To compile this driver as a module, choose M here: the
>> >> +       module will be called sun4i-ps2.
>> >> +
>> >>  endif
>> >> diff --git a/drivers/input/serio/Makefile b/drivers/input/serio/Makefile
>> >> index 815d874..c600089 100644
>> >> --- a/drivers/input/serio/Makefile
>> >> +++ b/drivers/input/serio/Makefile
>> >> @@ -29,3 +29,4 @@ obj-$(CONFIG_SERIO_ARC_PS2) += arc_ps2.o
>> >>  obj-$(CONFIG_SERIO_APBPS2)   += apbps2.o
>> >>  obj-$(CONFIG_SERIO_OLPC_APSP)        += olpc_apsp.o
>> >>  obj-$(CONFIG_HYPERV_KEYBOARD)        += hyperv-keyboard.o
>> >> +obj-$(CONFIG_SERIO_SUN4I_PS2)        += sun4i-ps2.o
>> >> diff --git a/drivers/input/serio/sun4i-ps2.c b/drivers/input/serio/sun4i-ps2.c
>> >> new file mode 100644
>> >> index 0000000..06b3fef
>> >> --- /dev/null
>> >> +++ b/drivers/input/serio/sun4i-ps2.c
>> >> @@ -0,0 +1,330 @@
>> >> +/*
>> >> + *   Driver for Allwinner A10 PS2 host controller
>> >> + *
>> >> + *   Author: Vishnu Patekar <vishnupatekar0510@gmail.com>
>> >> + *           Aaron.maoye <leafy.myeh@newbietech.com>
>> >> + *
>> >> + *
>> >> + */
>> >> +
>> >> +#include <linux/module.h>
>> >> +#include <linux/serio.h>
>> >> +#include <linux/interrupt.h>
>> >> +#include <linux/errno.h>
>> >> +#include <linux/slab.h>
>> >> +#include <linux/list.h>
>> >> +#include <linux/io.h>
>> >> +#include <linux/of_address.h>
>> >> +#include <linux/of_device.h>
>> >> +#include <linux/of_irq.h>
>> >> +#include <linux/of_platform.h>
>> >> +#include <linux/clk.h>
>> >> +#include <linux/delay.h>
>> >> +
>> >> +#define DRIVER_NAME          "sun4i-ps2"
>> >> +
>> >> +/* register offset definitions */
>> >> +#define PS2_REG_GCTL         0x00    /*  PS2 Module Global Control Reg */
>> >> +#define PS2_REG_DATA         0x04    /*  PS2 Module Data Reg         */
>> >> +#define PS2_REG_LCTL         0x08    /*  PS2 Module Line Control Reg */
>> >> +#define PS2_REG_LSTS         0x0C    /*  PS2 Module Line Status Reg  */
>> >> +#define PS2_REG_FCTL         0x10    /*  PS2 Module FIFO Control Reg */
>> >> +#define PS2_REG_FSTS         0x14    /*  PS2 Module FIFO Status Reg  */
>> >> +#define PS2_REG_CLKDR                0x18    /*  PS2 Module Clock Divider Reg*/
>> >> +
>> >> +/*  PS2 GLOBAL CONTROL REGISTER PS2_GCTL */
>> >> +#define PS2_GCTL_INTFLAG     BIT(4)
>> >> +#define PS2_GCTL_INTEN               BIT(3)
>> >> +#define PS2_GCTL_RESET               BIT(2)
>> >> +#define PS2_GCTL_MASTER              BIT(1)
>> >> +#define PS2_GCTL_BUSEN               BIT(0)
>> >> +
>> >> +/* PS2 LINE CONTROL REGISTER */
>> >> +#define PS2_LCTL_NOACK               BIT(18)
>> >> +#define PS2_LCTL_TXDTOEN     BIT(8)
>> >> +#define PS2_LCTL_STOPERREN   BIT(3)
>> >> +#define PS2_LCTL_ACKERREN    BIT(2)
>> >> +#define PS2_LCTL_PARERREN    BIT(1)
>> >> +#define PS2_LCTL_RXDTOEN     BIT(0)
>> >> +
>> >> +/* PS2 LINE STATUS REGISTER */
>> >> +#define PS2_LSTS_TXTDO               BIT(8)
>> >> +#define PS2_LSTS_STOPERR     BIT(3)
>> >> +#define PS2_LSTS_ACKERR              BIT(2)
>> >> +#define PS2_LSTS_PARERR              BIT(1)
>> >> +#define PS2_LSTS_RXTDO               BIT(0)
>> >> +
>> >> +#define PS2_LINE_ERROR_BIT \
>> >> +     (PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR | \
>> >> +     PS2_LSTS_PARERR | PS2_LSTS_RXTDO)
>> >> +
>> >> +/* PS2 FIFO CONTROL REGISTER */
>> >> +#define PS2_FCTL_TXRST               BIT(17)
>> >> +#define PS2_FCTL_RXRST               BIT(16)
>> >> +#define PS2_FCTL_TXUFIEN     BIT(10)
>> >> +#define PS2_FCTL_TXOFIEN     BIT(9)
>> >> +#define PS2_FCTL_TXRDYIEN    BIT(8)
>> >> +#define PS2_FCTL_RXUFIEN     BIT(2)
>> >> +#define PS2_FCTL_RXOFIEN     BIT(1)
>> >> +#define PS2_FCTL_RXRDYIEN    BIT(0)
>> >> +
>> >> +/* PS2 FIFO STATUS REGISTER */
>> >> +#define PS2_FSTS_TXUF                BIT(10)
>> >> +#define PS2_FSTS_TXOF                BIT(9)
>> >> +#define PS2_FSTS_TXRDY               BIT(8)
>> >> +#define PS2_FSTS_RXUF                BIT(2)
>> >> +#define PS2_FSTS_RXOF                BIT(1)
>> >> +#define PS2_FSTS_RXRDY               BIT(0)
>> >> +
>> >> +#define PS2_FIFO_ERROR_BIT \
>> >> +     (PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_RXUF | PS2_FSTS_RXOF)
>> >> +
>> >> +#define PS2_SAMPLE_CLK               1000000
>> >> +#define PS2_SCLK             125000
>> >> +
>> >> +struct sun4i_ps2data {
>> >> +     struct serio *serio;
>> >> +     struct device *dev;
>> >> +
>> >> +     /* IO mapping base */
>> >> +     void __iomem    *reg_base;
>> >> +
>> >> +     /* clock management */
>> >> +     struct clk      *clk;
>> >> +
>> >> +     /* irq */
>> >> +     spinlock_t      lock;
>> >> +     int             irq;
>> >> +};
>> >> +
>> >> +/*********************/
>> >> +/* Interrupt handler */
>> >> +/*********************/
>> >> +static irqreturn_t sun4i_ps2_interrupt(int irq, void *dev_id)
>> >> +{
>> >> +     struct sun4i_ps2data *drvdata = dev_id;
>> >> +     u32 intr_status;
>> >> +     u32 fifo_status;
>> >> +     unsigned char byte;
>> >> +     unsigned int rxflags = 0;
>> >> +     u32 rval;
>> >> +
>> >> +     spin_lock(&drvdata->lock);
>> >> +
>> >> +     /* Get the PS/2 interrupts and clear them */
>> >> +     intr_status  = readl(drvdata->reg_base + PS2_REG_LSTS);
>> >> +     fifo_status  = readl(drvdata->reg_base + PS2_REG_FSTS);
>> >> +
>> >> +     /*Check Line Status Register*/
>> >> +     if (intr_status & PS2_LINE_ERROR_BIT) {
>> >> +             rxflags = (intr_status & PS2_LINE_ERROR_BIT) ? SERIO_FRAME : 0;
>> >> +             rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_PARITY : 0;
>> >> +             rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_TIMEOUT : 0;
>> >> +
>> >> +             rval = PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR |
>> >> +                     PS2_LSTS_PARERR | PS2_LSTS_RXTDO;
>> >> +             writel(rval, drvdata->reg_base + PS2_REG_LSTS);
>> >> +     }
>> >> +
>> >> +     /*Check FIFO Status Register*/
>> >> +     if (fifo_status & PS2_FIFO_ERROR_BIT) {
>> >> +             rval = PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_TXRDY |
>> >> +                     PS2_FSTS_RXUF | PS2_FSTS_RXOF | PS2_FSTS_RXRDY;
>> >> +             writel(rval, drvdata->reg_base + PS2_REG_FSTS);
>> >> +     }
>> >> +
>> >> +     rval = (fifo_status >> 16) & 0x3;
>> >> +     while (rval--) {
>> >> +             byte = readl(drvdata->reg_base + PS2_REG_DATA) & 0xff;
>> >> +             serio_interrupt(drvdata->serio, byte, rxflags);
>> >> +     }
>> >> +
>> >> +     writel(intr_status, drvdata->reg_base + PS2_REG_LSTS);
>> >> +     writel(fifo_status, drvdata->reg_base + PS2_REG_FSTS);
>> >> +
>> >> +     spin_unlock(&drvdata->lock);
>> >> +
>> >> +     return IRQ_HANDLED;
>> >> +}
>> >> +
>> >> +
>> >> +static int sun4i_ps2_open(struct serio *pserio)
>> >> +{
>> >> +     struct sun4i_ps2data *drvdata = pserio->port_data;
>> >> +     u32 src_clk = 0;
>> >> +     u32 clk_scdf;
>> >> +     u32 clk_pcdf;
>> >> +     u32 rval;
>> >> +     unsigned long flags;
>> >> +
>> >> +     /*Set Line Control And Enable Interrupt*/
>> >> +     rval = PS2_LCTL_STOPERREN | PS2_LCTL_ACKERREN
>> >> +             | PS2_LCTL_PARERREN | PS2_LCTL_RXDTOEN;
>> >> +     writel(rval, drvdata->reg_base + PS2_REG_LCTL);
>> >> +
>> >> +     /*Reset FIFO*/
>> >> +     rval = PS2_FCTL_TXRST | PS2_FCTL_RXRST | PS2_FCTL_TXUFIEN
>> >> +             | PS2_FCTL_TXOFIEN | PS2_FCTL_RXUFIEN
>> >> +             | PS2_FCTL_RXOFIEN | PS2_FCTL_RXRDYIEN;
>> >> +
>> >> +     writel(rval, drvdata->reg_base + PS2_REG_FCTL);
>> >> +
>> >> +     src_clk = clk_get_rate(drvdata->clk);
>> >> +     /*Set Clock Divider Register*/
>> >> +     clk_scdf = src_clk / PS2_SAMPLE_CLK - 1;
>> >> +     clk_pcdf = PS2_SAMPLE_CLK / PS2_SCLK - 1;
>> >> +     rval = (clk_scdf<<8) | clk_pcdf;
>> >> +     writel(rval, drvdata->reg_base + PS2_REG_CLKDR);
>> >> +
>> >> +
>> >> +     /*Set Global Control Register*/
>> >> +     rval = PS2_GCTL_RESET | PS2_GCTL_INTEN | PS2_GCTL_MASTER
>> >> +             | PS2_GCTL_BUSEN;
>> >> +
>> >> +     spin_lock_irqsave(&drvdata->lock, flags);
>> >> +     writel(rval, drvdata->reg_base + PS2_REG_GCTL);
>> >> +     spin_unlock_irqrestore(&drvdata->lock, flags);
>> >> +
>> >> +     return 0;
>> >> +}
>> >> +
>> >> +static void sun4i_ps2_close(struct serio *pserio)
>> >> +{
>> >> +     struct sun4i_ps2data *drvdata = pserio->port_data;
>> >> +
>> >> +     synchronize_irq(drvdata->irq);
>> >
>> > synchronize_irq() on it's own is not very useful. You also need to shut
>> > off interrupts on the chip (I suppose by clearing PS2_GCTL_INTEN?)
>> > before calling synchronize_irq.
>> Okie, I'll do it. Yes, clearing PS2_GCTL_INTEN will shut off the interrupts.
>
> Please also do shut off interrupts on the chip before requesting IRQ.
Okie
>
>> >
>> >> +}
>> >> +
>> >> +static int sun4i_ps2_write(struct serio *pserio, unsigned char val)
>> >> +{
>> >> +     unsigned long expire = jiffies + msecs_to_jiffies(10000);
>> >> +     struct sun4i_ps2data *drvdata;
>> >> +
>> >> +     drvdata = (struct sun4i_ps2data *)pserio->port_data;
>> >> +
>> >> +     do {
>> >> +             if (readl(drvdata->reg_base + PS2_REG_FSTS) & PS2_FSTS_TXRDY) {
>> >> +                     writel(val, drvdata->reg_base + PS2_REG_DATA);
>> >> +                     return 0;
>> >> +             }
>> >> +     } while (time_before(jiffies, expire));
>> >> +
>> >> +     return SERIO_TIMEOUT;
>> >> +}
>> >> +
>> >> +static int sun4i_ps2_probe(struct platform_device *pdev)
>> >> +{
>> >> +     struct resource *res; /* IO mem resources */
>> >> +     struct sun4i_ps2data *drvdata;
>> >> +     struct serio *serio;
>> >> +     struct device *dev = &pdev->dev;
>> >> +     unsigned int irq;
>> >> +     int error;
>> >> +
>> >> +     drvdata = devm_kzalloc(dev, sizeof(struct sun4i_ps2data), GFP_KERNEL);
>> >> +     serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
>> >> +     if (!drvdata || !serio) {
>> >> +             error = -ENOMEM;
>> >> +             goto err_free_mem;
>> >> +     }
>> >> +
>> >> +     spin_lock_init(&drvdata->lock);
>> >> +
>> >> +     /* IO */
>> >> +     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> >> +     drvdata->reg_base = devm_ioremap_resource(dev, res);
>> >> +     if (IS_ERR(drvdata->reg_base)) {
>> >> +             dev_err(dev, "failed to map registers\n");
>> >> +             error = PTR_ERR(drvdata->reg_base);
>> >> +             goto err_free_mem;
>> >> +     }
>> >> +
>> >> +     drvdata->clk = devm_clk_get(dev, NULL);
>> >> +     if (IS_ERR(drvdata->clk)) {
>> >> +             error = PTR_ERR(drvdata->clk);
>> >> +             dev_err(dev, "couldn't get clock %d\n", error);
>> >> +             goto err_free_mem;
>> >> +     }
>> >> +
>> >> +     error = clk_prepare_enable(drvdata->clk);
>> >> +     if (error) {
>> >> +             dev_err(dev, "failed to enable clock %d\n", error);
>> >> +             goto err_free_mem;
>> >> +     }
>> >> +
>> >> +     serio->id.type = SERIO_8042;
>> >> +     serio->write = sun4i_ps2_write;
>> >> +     serio->open = sun4i_ps2_open;
>> >> +     serio->close = sun4i_ps2_close;
>> >> +     serio->port_data = drvdata;
>> >> +     serio->dev.parent = dev;
>> >> +     strlcpy(serio->name, dev_name(dev), sizeof(serio->name));
>> >> +     strlcpy(serio->phys, dev_name(dev), sizeof(serio->phys));
>> >> +
>> >> +     /* Get IRQ for the device */
>> >> +     irq = platform_get_irq(pdev, 0);
>> >> +     if (!irq) {
>> >> +             dev_err(dev, "no IRQ found\n");
>> >> +             error = -ENXIO;
>> >> +             goto error_disable_clk;
>> >> +     }
>> >> +
>> >> +     drvdata->irq = irq;
>> >> +     drvdata->serio = serio;
>> >> +     drvdata->dev = dev;
>> >> +     error = devm_request_threaded_irq(dev, drvdata->irq,
>> >> +             sun4i_ps2_interrupt, NULL, 0, DRIVER_NAME, drvdata);
>> >> +
>> >> +     if (error) {
>> >> +             dev_err(drvdata->dev, "Interrupt alloc failed %d:error:%d\n",
>> >> +                     drvdata->irq, error);
>> >> +             goto error_disable_clk;
>> >> +     }
>> >> +
>> >> +     serio_register_port(serio);
>> >> +     platform_set_drvdata(pdev, drvdata);
>> >> +
>> >> +     return 0;       /* success */
>> >> +
>> >> +error_disable_clk:
>> >> +     clk_disable_unprepare(drvdata->clk);
>> >> +
>> >> +err_free_mem:
>> >> +     kfree(serio);
>> >> +     return error;
>> >> +}
>> >> +
>> >> +static int sun4i_ps2_remove(struct platform_device *pdev)
>> >> +{
>> >> +     struct sun4i_ps2data *drvdata = platform_get_drvdata(pdev);
>> >> +
>> >> +     serio_unregister_port(drvdata->serio);
>> >> +
>> >> +     if (!IS_ERR(drvdata->clk))
>> >> +             clk_disable_unprepare(drvdata->clk);
>> >> +     kfree(drvdata->serio);
>> >
>> > Serio is refcounted, you do not free it after its has been registered.
>> > Overall I'd rather you did not use devm* interfaces here since you are
>> > forced to mix managed and manually freed resources.
>> Okie, No need to free serio here.
>> If serio is not manually freed here, It is not freeing anything else manually.
>
> You are still unregistering the port manually and disabling the clock manually.
>>
>> do you still feel I should not use devm* interfaces here?
>
> Yes, because of above. My rule of thumb - when using devm* API there should not
> be remove() at all.
Okie, I'll remove devm* interfaces.

>
> BTW, if one added devm_* API to serio, similar to devm* in input core, I'd take
> such patch.
This seems a ultimate solution to use devm* interfaces. For now, I'll
just avoid using devm* interfaces.
Still, we have to manually disable the clock, didn't we?

Well, I saw your old devm_clk_* patch, it was not mainlined. Do we
have any other way to use managed clk interfaces?

any further information on this interesting patchset
?https://lkml.org/lkml/2012/11/20/173

>
> Thanks.
>
> --
> Dmitry
>
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Dmitry Torokhov Jan. 22, 2015, 8:07 p.m. UTC | #5
On Wed, Jan 21, 2015 at 04:52:04PM +0530, Vishnu Patekar wrote:
> Hello Dmitry,
> 
> On Tue, Jan 20, 2015 at 6:05 AM, Dmitry Torokhov
> <dmitry.torokhov@gmail.com> wrote:
> > On Mon, Jan 19, 2015 at 11:37:38AM +0530, Vishnu Patekar wrote:
> >> Hello Dmitry,
> >>
> >> Thank you for review comments. Please see in-lined.
> >>
> >> On Sun, Jan 18, 2015 at 3:55 AM, Dmitry Torokhov
> >> <dmitry.torokhov@gmail.com> wrote:
> >> > Hi Vishnu,
> >> >
> >> > On Fri, Jan 16, 2015 at 07:33:38PM +0530, Vishnu Patekar wrote:
> >> >> Signed-off-by: VishnuPatekar <vishnupatekar0510@gmail.com>
> >> >> ---
> >> >>  drivers/input/serio/Kconfig     |   11 ++
> >> >>  drivers/input/serio/Makefile    |    1 +
> >> >>  drivers/input/serio/sun4i-ps2.c |  330 +++++++++++++++++++++++++++++++++++++++
> >> >>  3 files changed, 342 insertions(+)
> >> >>  create mode 100644 drivers/input/serio/sun4i-ps2.c
> >> >>
> >> >> diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig
> >> >> index bc2d474..964afc5 100644
> >> >> --- a/drivers/input/serio/Kconfig
> >> >> +++ b/drivers/input/serio/Kconfig
> >> >> @@ -281,4 +281,15 @@ config HYPERV_KEYBOARD
> >> >>         To compile this driver as a module, choose M here: the module will
> >> >>         be called hyperv_keyboard.
> >> >>
> >> >> +config SERIO_SUN4I_PS2
> >> >> +     tristate "Allwinner A10 PS/2 controller support"
> >> >> +     default n
> >> >> +     depends on ARCH_SUNXI || COMPILE_TEST
> >> >> +     help
> >> >> +       This selects support for the PS/2 Host Controller on
> >> >> +       Allwinner A10.
> >> >> +
> >> >> +       To compile this driver as a module, choose M here: the
> >> >> +       module will be called sun4i-ps2.
> >> >> +
> >> >>  endif
> >> >> diff --git a/drivers/input/serio/Makefile b/drivers/input/serio/Makefile
> >> >> index 815d874..c600089 100644
> >> >> --- a/drivers/input/serio/Makefile
> >> >> +++ b/drivers/input/serio/Makefile
> >> >> @@ -29,3 +29,4 @@ obj-$(CONFIG_SERIO_ARC_PS2) += arc_ps2.o
> >> >>  obj-$(CONFIG_SERIO_APBPS2)   += apbps2.o
> >> >>  obj-$(CONFIG_SERIO_OLPC_APSP)        += olpc_apsp.o
> >> >>  obj-$(CONFIG_HYPERV_KEYBOARD)        += hyperv-keyboard.o
> >> >> +obj-$(CONFIG_SERIO_SUN4I_PS2)        += sun4i-ps2.o
> >> >> diff --git a/drivers/input/serio/sun4i-ps2.c b/drivers/input/serio/sun4i-ps2.c
> >> >> new file mode 100644
> >> >> index 0000000..06b3fef
> >> >> --- /dev/null
> >> >> +++ b/drivers/input/serio/sun4i-ps2.c
> >> >> @@ -0,0 +1,330 @@
> >> >> +/*
> >> >> + *   Driver for Allwinner A10 PS2 host controller
> >> >> + *
> >> >> + *   Author: Vishnu Patekar <vishnupatekar0510@gmail.com>
> >> >> + *           Aaron.maoye <leafy.myeh@newbietech.com>
> >> >> + *
> >> >> + *
> >> >> + */
> >> >> +
> >> >> +#include <linux/module.h>
> >> >> +#include <linux/serio.h>
> >> >> +#include <linux/interrupt.h>
> >> >> +#include <linux/errno.h>
> >> >> +#include <linux/slab.h>
> >> >> +#include <linux/list.h>
> >> >> +#include <linux/io.h>
> >> >> +#include <linux/of_address.h>
> >> >> +#include <linux/of_device.h>
> >> >> +#include <linux/of_irq.h>
> >> >> +#include <linux/of_platform.h>
> >> >> +#include <linux/clk.h>
> >> >> +#include <linux/delay.h>
> >> >> +
> >> >> +#define DRIVER_NAME          "sun4i-ps2"
> >> >> +
> >> >> +/* register offset definitions */
> >> >> +#define PS2_REG_GCTL         0x00    /*  PS2 Module Global Control Reg */
> >> >> +#define PS2_REG_DATA         0x04    /*  PS2 Module Data Reg         */
> >> >> +#define PS2_REG_LCTL         0x08    /*  PS2 Module Line Control Reg */
> >> >> +#define PS2_REG_LSTS         0x0C    /*  PS2 Module Line Status Reg  */
> >> >> +#define PS2_REG_FCTL         0x10    /*  PS2 Module FIFO Control Reg */
> >> >> +#define PS2_REG_FSTS         0x14    /*  PS2 Module FIFO Status Reg  */
> >> >> +#define PS2_REG_CLKDR                0x18    /*  PS2 Module Clock Divider Reg*/
> >> >> +
> >> >> +/*  PS2 GLOBAL CONTROL REGISTER PS2_GCTL */
> >> >> +#define PS2_GCTL_INTFLAG     BIT(4)
> >> >> +#define PS2_GCTL_INTEN               BIT(3)
> >> >> +#define PS2_GCTL_RESET               BIT(2)
> >> >> +#define PS2_GCTL_MASTER              BIT(1)
> >> >> +#define PS2_GCTL_BUSEN               BIT(0)
> >> >> +
> >> >> +/* PS2 LINE CONTROL REGISTER */
> >> >> +#define PS2_LCTL_NOACK               BIT(18)
> >> >> +#define PS2_LCTL_TXDTOEN     BIT(8)
> >> >> +#define PS2_LCTL_STOPERREN   BIT(3)
> >> >> +#define PS2_LCTL_ACKERREN    BIT(2)
> >> >> +#define PS2_LCTL_PARERREN    BIT(1)
> >> >> +#define PS2_LCTL_RXDTOEN     BIT(0)
> >> >> +
> >> >> +/* PS2 LINE STATUS REGISTER */
> >> >> +#define PS2_LSTS_TXTDO               BIT(8)
> >> >> +#define PS2_LSTS_STOPERR     BIT(3)
> >> >> +#define PS2_LSTS_ACKERR              BIT(2)
> >> >> +#define PS2_LSTS_PARERR              BIT(1)
> >> >> +#define PS2_LSTS_RXTDO               BIT(0)
> >> >> +
> >> >> +#define PS2_LINE_ERROR_BIT \
> >> >> +     (PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR | \
> >> >> +     PS2_LSTS_PARERR | PS2_LSTS_RXTDO)
> >> >> +
> >> >> +/* PS2 FIFO CONTROL REGISTER */
> >> >> +#define PS2_FCTL_TXRST               BIT(17)
> >> >> +#define PS2_FCTL_RXRST               BIT(16)
> >> >> +#define PS2_FCTL_TXUFIEN     BIT(10)
> >> >> +#define PS2_FCTL_TXOFIEN     BIT(9)
> >> >> +#define PS2_FCTL_TXRDYIEN    BIT(8)
> >> >> +#define PS2_FCTL_RXUFIEN     BIT(2)
> >> >> +#define PS2_FCTL_RXOFIEN     BIT(1)
> >> >> +#define PS2_FCTL_RXRDYIEN    BIT(0)
> >> >> +
> >> >> +/* PS2 FIFO STATUS REGISTER */
> >> >> +#define PS2_FSTS_TXUF                BIT(10)
> >> >> +#define PS2_FSTS_TXOF                BIT(9)
> >> >> +#define PS2_FSTS_TXRDY               BIT(8)
> >> >> +#define PS2_FSTS_RXUF                BIT(2)
> >> >> +#define PS2_FSTS_RXOF                BIT(1)
> >> >> +#define PS2_FSTS_RXRDY               BIT(0)
> >> >> +
> >> >> +#define PS2_FIFO_ERROR_BIT \
> >> >> +     (PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_RXUF | PS2_FSTS_RXOF)
> >> >> +
> >> >> +#define PS2_SAMPLE_CLK               1000000
> >> >> +#define PS2_SCLK             125000
> >> >> +
> >> >> +struct sun4i_ps2data {
> >> >> +     struct serio *serio;
> >> >> +     struct device *dev;
> >> >> +
> >> >> +     /* IO mapping base */
> >> >> +     void __iomem    *reg_base;
> >> >> +
> >> >> +     /* clock management */
> >> >> +     struct clk      *clk;
> >> >> +
> >> >> +     /* irq */
> >> >> +     spinlock_t      lock;
> >> >> +     int             irq;
> >> >> +};
> >> >> +
> >> >> +/*********************/
> >> >> +/* Interrupt handler */
> >> >> +/*********************/
> >> >> +static irqreturn_t sun4i_ps2_interrupt(int irq, void *dev_id)
> >> >> +{
> >> >> +     struct sun4i_ps2data *drvdata = dev_id;
> >> >> +     u32 intr_status;
> >> >> +     u32 fifo_status;
> >> >> +     unsigned char byte;
> >> >> +     unsigned int rxflags = 0;
> >> >> +     u32 rval;
> >> >> +
> >> >> +     spin_lock(&drvdata->lock);
> >> >> +
> >> >> +     /* Get the PS/2 interrupts and clear them */
> >> >> +     intr_status  = readl(drvdata->reg_base + PS2_REG_LSTS);
> >> >> +     fifo_status  = readl(drvdata->reg_base + PS2_REG_FSTS);
> >> >> +
> >> >> +     /*Check Line Status Register*/
> >> >> +     if (intr_status & PS2_LINE_ERROR_BIT) {
> >> >> +             rxflags = (intr_status & PS2_LINE_ERROR_BIT) ? SERIO_FRAME : 0;
> >> >> +             rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_PARITY : 0;
> >> >> +             rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_TIMEOUT : 0;
> >> >> +
> >> >> +             rval = PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR |
> >> >> +                     PS2_LSTS_PARERR | PS2_LSTS_RXTDO;
> >> >> +             writel(rval, drvdata->reg_base + PS2_REG_LSTS);
> >> >> +     }
> >> >> +
> >> >> +     /*Check FIFO Status Register*/
> >> >> +     if (fifo_status & PS2_FIFO_ERROR_BIT) {
> >> >> +             rval = PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_TXRDY |
> >> >> +                     PS2_FSTS_RXUF | PS2_FSTS_RXOF | PS2_FSTS_RXRDY;
> >> >> +             writel(rval, drvdata->reg_base + PS2_REG_FSTS);
> >> >> +     }
> >> >> +
> >> >> +     rval = (fifo_status >> 16) & 0x3;
> >> >> +     while (rval--) {
> >> >> +             byte = readl(drvdata->reg_base + PS2_REG_DATA) & 0xff;
> >> >> +             serio_interrupt(drvdata->serio, byte, rxflags);
> >> >> +     }
> >> >> +
> >> >> +     writel(intr_status, drvdata->reg_base + PS2_REG_LSTS);
> >> >> +     writel(fifo_status, drvdata->reg_base + PS2_REG_FSTS);
> >> >> +
> >> >> +     spin_unlock(&drvdata->lock);
> >> >> +
> >> >> +     return IRQ_HANDLED;
> >> >> +}
> >> >> +
> >> >> +
> >> >> +static int sun4i_ps2_open(struct serio *pserio)
> >> >> +{
> >> >> +     struct sun4i_ps2data *drvdata = pserio->port_data;
> >> >> +     u32 src_clk = 0;
> >> >> +     u32 clk_scdf;
> >> >> +     u32 clk_pcdf;
> >> >> +     u32 rval;
> >> >> +     unsigned long flags;
> >> >> +
> >> >> +     /*Set Line Control And Enable Interrupt*/
> >> >> +     rval = PS2_LCTL_STOPERREN | PS2_LCTL_ACKERREN
> >> >> +             | PS2_LCTL_PARERREN | PS2_LCTL_RXDTOEN;
> >> >> +     writel(rval, drvdata->reg_base + PS2_REG_LCTL);
> >> >> +
> >> >> +     /*Reset FIFO*/
> >> >> +     rval = PS2_FCTL_TXRST | PS2_FCTL_RXRST | PS2_FCTL_TXUFIEN
> >> >> +             | PS2_FCTL_TXOFIEN | PS2_FCTL_RXUFIEN
> >> >> +             | PS2_FCTL_RXOFIEN | PS2_FCTL_RXRDYIEN;
> >> >> +
> >> >> +     writel(rval, drvdata->reg_base + PS2_REG_FCTL);
> >> >> +
> >> >> +     src_clk = clk_get_rate(drvdata->clk);
> >> >> +     /*Set Clock Divider Register*/
> >> >> +     clk_scdf = src_clk / PS2_SAMPLE_CLK - 1;
> >> >> +     clk_pcdf = PS2_SAMPLE_CLK / PS2_SCLK - 1;
> >> >> +     rval = (clk_scdf<<8) | clk_pcdf;
> >> >> +     writel(rval, drvdata->reg_base + PS2_REG_CLKDR);
> >> >> +
> >> >> +
> >> >> +     /*Set Global Control Register*/
> >> >> +     rval = PS2_GCTL_RESET | PS2_GCTL_INTEN | PS2_GCTL_MASTER
> >> >> +             | PS2_GCTL_BUSEN;
> >> >> +
> >> >> +     spin_lock_irqsave(&drvdata->lock, flags);
> >> >> +     writel(rval, drvdata->reg_base + PS2_REG_GCTL);
> >> >> +     spin_unlock_irqrestore(&drvdata->lock, flags);
> >> >> +
> >> >> +     return 0;
> >> >> +}
> >> >> +
> >> >> +static void sun4i_ps2_close(struct serio *pserio)
> >> >> +{
> >> >> +     struct sun4i_ps2data *drvdata = pserio->port_data;
> >> >> +
> >> >> +     synchronize_irq(drvdata->irq);
> >> >
> >> > synchronize_irq() on it's own is not very useful. You also need to shut
> >> > off interrupts on the chip (I suppose by clearing PS2_GCTL_INTEN?)
> >> > before calling synchronize_irq.
> >> Okie, I'll do it. Yes, clearing PS2_GCTL_INTEN will shut off the interrupts.
> >
> > Please also do shut off interrupts on the chip before requesting IRQ.
> Okie
> >
> >> >
> >> >> +}
> >> >> +
> >> >> +static int sun4i_ps2_write(struct serio *pserio, unsigned char val)
> >> >> +{
> >> >> +     unsigned long expire = jiffies + msecs_to_jiffies(10000);
> >> >> +     struct sun4i_ps2data *drvdata;
> >> >> +
> >> >> +     drvdata = (struct sun4i_ps2data *)pserio->port_data;
> >> >> +
> >> >> +     do {
> >> >> +             if (readl(drvdata->reg_base + PS2_REG_FSTS) & PS2_FSTS_TXRDY) {
> >> >> +                     writel(val, drvdata->reg_base + PS2_REG_DATA);
> >> >> +                     return 0;
> >> >> +             }
> >> >> +     } while (time_before(jiffies, expire));
> >> >> +
> >> >> +     return SERIO_TIMEOUT;
> >> >> +}
> >> >> +
> >> >> +static int sun4i_ps2_probe(struct platform_device *pdev)
> >> >> +{
> >> >> +     struct resource *res; /* IO mem resources */
> >> >> +     struct sun4i_ps2data *drvdata;
> >> >> +     struct serio *serio;
> >> >> +     struct device *dev = &pdev->dev;
> >> >> +     unsigned int irq;
> >> >> +     int error;
> >> >> +
> >> >> +     drvdata = devm_kzalloc(dev, sizeof(struct sun4i_ps2data), GFP_KERNEL);
> >> >> +     serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
> >> >> +     if (!drvdata || !serio) {
> >> >> +             error = -ENOMEM;
> >> >> +             goto err_free_mem;
> >> >> +     }
> >> >> +
> >> >> +     spin_lock_init(&drvdata->lock);
> >> >> +
> >> >> +     /* IO */
> >> >> +     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >> >> +     drvdata->reg_base = devm_ioremap_resource(dev, res);
> >> >> +     if (IS_ERR(drvdata->reg_base)) {
> >> >> +             dev_err(dev, "failed to map registers\n");
> >> >> +             error = PTR_ERR(drvdata->reg_base);
> >> >> +             goto err_free_mem;
> >> >> +     }
> >> >> +
> >> >> +     drvdata->clk = devm_clk_get(dev, NULL);
> >> >> +     if (IS_ERR(drvdata->clk)) {
> >> >> +             error = PTR_ERR(drvdata->clk);
> >> >> +             dev_err(dev, "couldn't get clock %d\n", error);
> >> >> +             goto err_free_mem;
> >> >> +     }
> >> >> +
> >> >> +     error = clk_prepare_enable(drvdata->clk);
> >> >> +     if (error) {
> >> >> +             dev_err(dev, "failed to enable clock %d\n", error);
> >> >> +             goto err_free_mem;
> >> >> +     }
> >> >> +
> >> >> +     serio->id.type = SERIO_8042;
> >> >> +     serio->write = sun4i_ps2_write;
> >> >> +     serio->open = sun4i_ps2_open;
> >> >> +     serio->close = sun4i_ps2_close;
> >> >> +     serio->port_data = drvdata;
> >> >> +     serio->dev.parent = dev;
> >> >> +     strlcpy(serio->name, dev_name(dev), sizeof(serio->name));
> >> >> +     strlcpy(serio->phys, dev_name(dev), sizeof(serio->phys));
> >> >> +
> >> >> +     /* Get IRQ for the device */
> >> >> +     irq = platform_get_irq(pdev, 0);
> >> >> +     if (!irq) {
> >> >> +             dev_err(dev, "no IRQ found\n");
> >> >> +             error = -ENXIO;
> >> >> +             goto error_disable_clk;
> >> >> +     }
> >> >> +
> >> >> +     drvdata->irq = irq;
> >> >> +     drvdata->serio = serio;
> >> >> +     drvdata->dev = dev;
> >> >> +     error = devm_request_threaded_irq(dev, drvdata->irq,
> >> >> +             sun4i_ps2_interrupt, NULL, 0, DRIVER_NAME, drvdata);
> >> >> +
> >> >> +     if (error) {
> >> >> +             dev_err(drvdata->dev, "Interrupt alloc failed %d:error:%d\n",
> >> >> +                     drvdata->irq, error);
> >> >> +             goto error_disable_clk;
> >> >> +     }
> >> >> +
> >> >> +     serio_register_port(serio);
> >> >> +     platform_set_drvdata(pdev, drvdata);
> >> >> +
> >> >> +     return 0;       /* success */
> >> >> +
> >> >> +error_disable_clk:
> >> >> +     clk_disable_unprepare(drvdata->clk);
> >> >> +
> >> >> +err_free_mem:
> >> >> +     kfree(serio);
> >> >> +     return error;
> >> >> +}
> >> >> +
> >> >> +static int sun4i_ps2_remove(struct platform_device *pdev)
> >> >> +{
> >> >> +     struct sun4i_ps2data *drvdata = platform_get_drvdata(pdev);
> >> >> +
> >> >> +     serio_unregister_port(drvdata->serio);
> >> >> +
> >> >> +     if (!IS_ERR(drvdata->clk))
> >> >> +             clk_disable_unprepare(drvdata->clk);
> >> >> +     kfree(drvdata->serio);
> >> >
> >> > Serio is refcounted, you do not free it after its has been registered.
> >> > Overall I'd rather you did not use devm* interfaces here since you are
> >> > forced to mix managed and manually freed resources.
> >> Okie, No need to free serio here.
> >> If serio is not manually freed here, It is not freeing anything else manually.
> >
> > You are still unregistering the port manually and disabling the clock manually.
> >>
> >> do you still feel I should not use devm* interfaces here?
> >
> > Yes, because of above. My rule of thumb - when using devm* API there should not
> > be remove() at all.
> Okie, I'll remove devm* interfaces.
> 
> >
> > BTW, if one added devm_* API to serio, similar to devm* in input core, I'd take
> > such patch.
> This seems a ultimate solution to use devm* interfaces. For now, I'll
> just avoid using devm* interfaces.
> Still, we have to manually disable the clock, didn't we?
> 
> Well, I saw your old devm_clk_* patch, it was not mainlined. Do we
> have any other way to use managed clk interfaces?

No, I really need to pick it back up...

Thanks.
diff mbox

Patch

diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig
index bc2d474..964afc5 100644
--- a/drivers/input/serio/Kconfig
+++ b/drivers/input/serio/Kconfig
@@ -281,4 +281,15 @@  config HYPERV_KEYBOARD
 	  To compile this driver as a module, choose M here: the module will
 	  be called hyperv_keyboard.
 
+config SERIO_SUN4I_PS2
+	tristate "Allwinner A10 PS/2 controller support"
+	default n
+	depends on ARCH_SUNXI || COMPILE_TEST
+	help
+	  This selects support for the PS/2 Host Controller on
+	  Allwinner A10.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called sun4i-ps2.
+
 endif
diff --git a/drivers/input/serio/Makefile b/drivers/input/serio/Makefile
index 815d874..c600089 100644
--- a/drivers/input/serio/Makefile
+++ b/drivers/input/serio/Makefile
@@ -29,3 +29,4 @@  obj-$(CONFIG_SERIO_ARC_PS2)	+= arc_ps2.o
 obj-$(CONFIG_SERIO_APBPS2)	+= apbps2.o
 obj-$(CONFIG_SERIO_OLPC_APSP)	+= olpc_apsp.o
 obj-$(CONFIG_HYPERV_KEYBOARD)	+= hyperv-keyboard.o
+obj-$(CONFIG_SERIO_SUN4I_PS2)	+= sun4i-ps2.o
diff --git a/drivers/input/serio/sun4i-ps2.c b/drivers/input/serio/sun4i-ps2.c
new file mode 100644
index 0000000..06b3fef
--- /dev/null
+++ b/drivers/input/serio/sun4i-ps2.c
@@ -0,0 +1,330 @@ 
+/*
+ *	Driver for Allwinner A10 PS2 host controller
+ *
+ *	Author: Vishnu Patekar <vishnupatekar0510@gmail.com>
+ *		Aaron.maoye <leafy.myeh@newbietech.com>
+ *
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/serio.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+
+#define DRIVER_NAME		"sun4i-ps2"
+
+/* register offset definitions */
+#define PS2_REG_GCTL		0x00	/*  PS2 Module Global Control Reg */
+#define PS2_REG_DATA		0x04	/*  PS2 Module Data Reg		*/
+#define PS2_REG_LCTL		0x08	/*  PS2 Module Line Control Reg */
+#define PS2_REG_LSTS		0x0C	/*  PS2 Module Line Status Reg	*/
+#define PS2_REG_FCTL		0x10	/*  PS2 Module FIFO Control Reg */
+#define PS2_REG_FSTS		0x14	/*  PS2 Module FIFO Status Reg	*/
+#define PS2_REG_CLKDR		0x18	/*  PS2 Module Clock Divider Reg*/
+
+/*  PS2 GLOBAL CONTROL REGISTER PS2_GCTL */
+#define PS2_GCTL_INTFLAG	BIT(4)
+#define PS2_GCTL_INTEN		BIT(3)
+#define PS2_GCTL_RESET		BIT(2)
+#define PS2_GCTL_MASTER		BIT(1)
+#define PS2_GCTL_BUSEN		BIT(0)
+
+/* PS2 LINE CONTROL REGISTER */
+#define PS2_LCTL_NOACK		BIT(18)
+#define PS2_LCTL_TXDTOEN	BIT(8)
+#define PS2_LCTL_STOPERREN	BIT(3)
+#define PS2_LCTL_ACKERREN	BIT(2)
+#define PS2_LCTL_PARERREN	BIT(1)
+#define PS2_LCTL_RXDTOEN	BIT(0)
+
+/* PS2 LINE STATUS REGISTER */
+#define PS2_LSTS_TXTDO		BIT(8)
+#define PS2_LSTS_STOPERR	BIT(3)
+#define PS2_LSTS_ACKERR		BIT(2)
+#define PS2_LSTS_PARERR		BIT(1)
+#define PS2_LSTS_RXTDO		BIT(0)
+
+#define PS2_LINE_ERROR_BIT \
+	(PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR | \
+	PS2_LSTS_PARERR | PS2_LSTS_RXTDO)
+
+/* PS2 FIFO CONTROL REGISTER */
+#define PS2_FCTL_TXRST		BIT(17)
+#define PS2_FCTL_RXRST		BIT(16)
+#define PS2_FCTL_TXUFIEN	BIT(10)
+#define PS2_FCTL_TXOFIEN	BIT(9)
+#define PS2_FCTL_TXRDYIEN	BIT(8)
+#define PS2_FCTL_RXUFIEN	BIT(2)
+#define PS2_FCTL_RXOFIEN	BIT(1)
+#define PS2_FCTL_RXRDYIEN	BIT(0)
+
+/* PS2 FIFO STATUS REGISTER */
+#define PS2_FSTS_TXUF		BIT(10)
+#define PS2_FSTS_TXOF		BIT(9)
+#define PS2_FSTS_TXRDY		BIT(8)
+#define PS2_FSTS_RXUF		BIT(2)
+#define PS2_FSTS_RXOF		BIT(1)
+#define PS2_FSTS_RXRDY		BIT(0)
+
+#define PS2_FIFO_ERROR_BIT \
+	(PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_RXUF | PS2_FSTS_RXOF)
+
+#define PS2_SAMPLE_CLK		1000000
+#define PS2_SCLK		125000
+
+struct sun4i_ps2data {
+	struct serio *serio;
+	struct device *dev;
+
+	/* IO mapping base */
+	void __iomem	*reg_base;
+
+	/* clock management */
+	struct clk	*clk;
+
+	/* irq */
+	spinlock_t	lock;
+	int		irq;
+};
+
+/*********************/
+/* Interrupt handler */
+/*********************/
+static irqreturn_t sun4i_ps2_interrupt(int irq, void *dev_id)
+{
+	struct sun4i_ps2data *drvdata = dev_id;
+	u32 intr_status;
+	u32 fifo_status;
+	unsigned char byte;
+	unsigned int rxflags = 0;
+	u32 rval;
+
+	spin_lock(&drvdata->lock);
+
+	/* Get the PS/2 interrupts and clear them */
+	intr_status  = readl(drvdata->reg_base + PS2_REG_LSTS);
+	fifo_status  = readl(drvdata->reg_base + PS2_REG_FSTS);
+
+	/*Check Line Status Register*/
+	if (intr_status & PS2_LINE_ERROR_BIT) {
+		rxflags = (intr_status & PS2_LINE_ERROR_BIT) ? SERIO_FRAME : 0;
+		rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_PARITY : 0;
+		rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_TIMEOUT : 0;
+
+		rval = PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR |
+			PS2_LSTS_PARERR | PS2_LSTS_RXTDO;
+		writel(rval, drvdata->reg_base + PS2_REG_LSTS);
+	}
+
+	/*Check FIFO Status Register*/
+	if (fifo_status & PS2_FIFO_ERROR_BIT) {
+		rval = PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_TXRDY |
+			PS2_FSTS_RXUF | PS2_FSTS_RXOF | PS2_FSTS_RXRDY;
+		writel(rval, drvdata->reg_base + PS2_REG_FSTS);
+	}
+
+	rval = (fifo_status >> 16) & 0x3;
+	while (rval--) {
+		byte = readl(drvdata->reg_base + PS2_REG_DATA) & 0xff;
+		serio_interrupt(drvdata->serio, byte, rxflags);
+	}
+
+	writel(intr_status, drvdata->reg_base + PS2_REG_LSTS);
+	writel(fifo_status, drvdata->reg_base + PS2_REG_FSTS);
+
+	spin_unlock(&drvdata->lock);
+
+	return IRQ_HANDLED;
+}
+
+
+static int sun4i_ps2_open(struct serio *pserio)
+{
+	struct sun4i_ps2data *drvdata = pserio->port_data;
+	u32 src_clk = 0;
+	u32 clk_scdf;
+	u32 clk_pcdf;
+	u32 rval;
+	unsigned long flags;
+
+	/*Set Line Control And Enable Interrupt*/
+	rval = PS2_LCTL_STOPERREN | PS2_LCTL_ACKERREN
+		| PS2_LCTL_PARERREN | PS2_LCTL_RXDTOEN;
+	writel(rval, drvdata->reg_base + PS2_REG_LCTL);
+
+	/*Reset FIFO*/
+	rval = PS2_FCTL_TXRST | PS2_FCTL_RXRST | PS2_FCTL_TXUFIEN
+		| PS2_FCTL_TXOFIEN | PS2_FCTL_RXUFIEN
+		| PS2_FCTL_RXOFIEN | PS2_FCTL_RXRDYIEN;
+
+	writel(rval, drvdata->reg_base + PS2_REG_FCTL);
+
+	src_clk = clk_get_rate(drvdata->clk);
+	/*Set Clock Divider Register*/
+	clk_scdf = src_clk / PS2_SAMPLE_CLK - 1;
+	clk_pcdf = PS2_SAMPLE_CLK / PS2_SCLK - 1;
+	rval = (clk_scdf<<8) | clk_pcdf;
+	writel(rval, drvdata->reg_base + PS2_REG_CLKDR);
+
+
+	/*Set Global Control Register*/
+	rval = PS2_GCTL_RESET | PS2_GCTL_INTEN | PS2_GCTL_MASTER
+		| PS2_GCTL_BUSEN;
+
+	spin_lock_irqsave(&drvdata->lock, flags);
+	writel(rval, drvdata->reg_base + PS2_REG_GCTL);
+	spin_unlock_irqrestore(&drvdata->lock, flags);
+
+	return 0;
+}
+
+static void sun4i_ps2_close(struct serio *pserio)
+{
+	struct sun4i_ps2data *drvdata = pserio->port_data;
+
+	synchronize_irq(drvdata->irq);
+}
+
+static int sun4i_ps2_write(struct serio *pserio, unsigned char val)
+{
+	unsigned long expire = jiffies + msecs_to_jiffies(10000);
+	struct sun4i_ps2data *drvdata;
+
+	drvdata = (struct sun4i_ps2data *)pserio->port_data;
+
+	do {
+		if (readl(drvdata->reg_base + PS2_REG_FSTS) & PS2_FSTS_TXRDY) {
+			writel(val, drvdata->reg_base + PS2_REG_DATA);
+			return 0;
+		}
+	} while (time_before(jiffies, expire));
+
+	return SERIO_TIMEOUT;
+}
+
+static int sun4i_ps2_probe(struct platform_device *pdev)
+{
+	struct resource *res; /* IO mem resources */
+	struct sun4i_ps2data *drvdata;
+	struct serio *serio;
+	struct device *dev = &pdev->dev;
+	unsigned int irq;
+	int error;
+
+	drvdata = devm_kzalloc(dev, sizeof(struct sun4i_ps2data), GFP_KERNEL);
+	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
+	if (!drvdata || !serio) {
+		error = -ENOMEM;
+		goto err_free_mem;
+	}
+
+	spin_lock_init(&drvdata->lock);
+
+	/* IO */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	drvdata->reg_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(drvdata->reg_base)) {
+		dev_err(dev, "failed to map registers\n");
+		error = PTR_ERR(drvdata->reg_base);
+		goto err_free_mem;
+	}
+
+	drvdata->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(drvdata->clk)) {
+		error = PTR_ERR(drvdata->clk);
+		dev_err(dev, "couldn't get clock %d\n", error);
+		goto err_free_mem;
+	}
+
+	error = clk_prepare_enable(drvdata->clk);
+	if (error) {
+		dev_err(dev, "failed to enable clock %d\n", error);
+		goto err_free_mem;
+	}
+
+	serio->id.type = SERIO_8042;
+	serio->write = sun4i_ps2_write;
+	serio->open = sun4i_ps2_open;
+	serio->close = sun4i_ps2_close;
+	serio->port_data = drvdata;
+	serio->dev.parent = dev;
+	strlcpy(serio->name, dev_name(dev), sizeof(serio->name));
+	strlcpy(serio->phys, dev_name(dev), sizeof(serio->phys));
+
+	/* Get IRQ for the device */
+	irq = platform_get_irq(pdev, 0);
+	if (!irq) {
+		dev_err(dev, "no IRQ found\n");
+		error = -ENXIO;
+		goto error_disable_clk;
+	}
+
+	drvdata->irq = irq;
+	drvdata->serio = serio;
+	drvdata->dev = dev;
+	error = devm_request_threaded_irq(dev, drvdata->irq,
+		sun4i_ps2_interrupt, NULL, 0, DRIVER_NAME, drvdata);
+
+	if (error) {
+		dev_err(drvdata->dev, "Interrupt alloc failed %d:error:%d\n",
+			drvdata->irq, error);
+		goto error_disable_clk;
+	}
+
+	serio_register_port(serio);
+	platform_set_drvdata(pdev, drvdata);
+
+	return 0;	/* success */
+
+error_disable_clk:
+	clk_disable_unprepare(drvdata->clk);
+
+err_free_mem:
+	kfree(serio);
+	return error;
+}
+
+static int sun4i_ps2_remove(struct platform_device *pdev)
+{
+	struct sun4i_ps2data *drvdata = platform_get_drvdata(pdev);
+
+	serio_unregister_port(drvdata->serio);
+
+	if (!IS_ERR(drvdata->clk))
+		clk_disable_unprepare(drvdata->clk);
+	kfree(drvdata->serio);
+
+	return 0;
+}
+
+static const struct of_device_id sun4i_ps2_match[] = {
+	{ .compatible = "allwinner,sun4i-a10-ps2", },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(of, sun4i_ps2_match);
+
+static struct platform_driver sun4i_ps2_driver = {
+	.probe		= sun4i_ps2_probe,
+	.remove		= sun4i_ps2_remove,
+	.driver = {
+		.name = DRIVER_NAME,
+		.of_match_table = sun4i_ps2_match,
+	},
+};
+module_platform_driver(sun4i_ps2_driver);
+
+MODULE_AUTHOR("Vishnu Patekar <vishnupatekar0510@gmail.com>");
+MODULE_AUTHOR("Aaron.maoye <leafy.myeh@newbietech.com>");
+MODULE_DESCRIPTION("Allwinner A10/Sun4i PS/2 driver");
+MODULE_LICENSE("GPL v2");