diff mbox

[v5,1/3] mailbox: Add support for APM X-Gene platform mailbox driver

Message ID 90cb13a0b4d3817c18c11c183128c08d6458bf8d.1454967957.git.dhdang@apm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Duc Dang Feb. 8, 2016, 10:04 p.m. UTC
X-Gene mailbox controller provides 8 mailbox channels, with
each channel has a dedicated interrupt line.

Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Duc Dang <dhdang@apm.com>
---
Changes since v4:
        - Rebase over v4.5-rc1
        - Fix section mistmatch warning by removing
        __init in slimpro_mbox_probe declaration
	- Correctly print channel number when
	there is no IRQ for that channel

Changes since v3:
        - Rebase over v4.4
        - Remove 'id' in slimpro_mbox_chan structure
        - Remove small functions that are only called once
        and fold them into the other callers
        - Remove void* pointer type cast
        - Relax the number of mailbox IRQs condition
        - Use subsys_initcall to guarantee mailbox driver
        will be registered before any other dependent driver
        is loaded.

 drivers/mailbox/Kconfig                 |   9 ++
 drivers/mailbox/Makefile                |   2 +
 drivers/mailbox/mailbox-xgene-slimpro.c | 264 ++++++++++++++++++++++++++++++++
 3 files changed, 275 insertions(+)
 create mode 100644 drivers/mailbox/mailbox-xgene-slimpro.c

Comments

Mathieu Poirier Feb. 9, 2016, 4:40 p.m. UTC | #1
On 8 February 2016 at 15:04, Duc Dang <dhdang@apm.com> wrote:
> X-Gene mailbox controller provides 8 mailbox channels, with
> each channel has a dedicated interrupt line.
>
> Signed-off-by: Feng Kan <fkan@apm.com>
> Signed-off-by: Duc Dang <dhdang@apm.com>
> ---
> Changes since v4:
>         - Rebase over v4.5-rc1
>         - Fix section mistmatch warning by removing
>         __init in slimpro_mbox_probe declaration
>         - Correctly print channel number when
>         there is no IRQ for that channel
>
> Changes since v3:
>         - Rebase over v4.4
>         - Remove 'id' in slimpro_mbox_chan structure
>         - Remove small functions that are only called once
>         and fold them into the other callers
>         - Remove void* pointer type cast
>         - Relax the number of mailbox IRQs condition
>         - Use subsys_initcall to guarantee mailbox driver
>         will be registered before any other dependent driver
>         is loaded.
>
>  drivers/mailbox/Kconfig                 |   9 ++
>  drivers/mailbox/Makefile                |   2 +
>  drivers/mailbox/mailbox-xgene-slimpro.c | 264 ++++++++++++++++++++++++++++++++
>  3 files changed, 275 insertions(+)
>  create mode 100644 drivers/mailbox/mailbox-xgene-slimpro.c
>
> diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
> index 546d05f..678e434 100644
> --- a/drivers/mailbox/Kconfig
> +++ b/drivers/mailbox/Kconfig
> @@ -85,4 +85,13 @@ config MAILBOX_TEST
>           Test client to help with testing new Controller driver
>           implementations.
>
> +config XGENE_SLIMPRO_MBOX
> +       tristate "APM SoC X-Gene SLIMpro Mailbox Controller"
> +       depends on ARCH_XGENE
> +       help
> +         An implementation of the APM X-Gene Interprocessor Communication
> +         Mailbox (IPCM) between the ARM 64-bit cores and SLIMpro controller.
> +         It is used to send short messages between ARM64-bit cores and
> +         the SLIMpro Management Engine, primarily for PM. Say Y here if you
> +         want to use the APM X-Gene SLIMpro IPCM support.
>  endif
> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
> index 92435ef..b602ef8 100644
> --- a/drivers/mailbox/Makefile
> +++ b/drivers/mailbox/Makefile
> @@ -17,3 +17,5 @@ obj-$(CONFIG_ALTERA_MBOX)     += mailbox-altera.o
>  obj-$(CONFIG_BCM2835_MBOX)     += bcm2835-mailbox.o
>
>  obj-$(CONFIG_STI_MBOX)         += mailbox-sti.o
> +
> +obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o
> diff --git a/drivers/mailbox/mailbox-xgene-slimpro.c b/drivers/mailbox/mailbox-xgene-slimpro.c
> new file mode 100644
> index 0000000..0ea1eb8
> --- /dev/null
> +++ b/drivers/mailbox/mailbox-xgene-slimpro.c
> @@ -0,0 +1,264 @@
> +/*
> + * APM X-Gene SLIMpro MailBox Driver
> + *
> + * Copyright (c) 2015, Applied Micro Circuits Corporation
> + * Author: Feng Kan fkan@apm.com
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation; either version 2 of
> + * the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, see <http://www.gnu.org/licenses/>.
> + *
> + */
> +#include <linux/acpi.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/mailbox_controller.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/spinlock.h>
> +
> +#define MBOX_CON_NAME                  "slimpro-mbox"
> +#define MBOX_REG_SET_OFFSET            0x1000
> +#define MBOX_CNT                       8
> +#define MBOX_STATUS_AVAIL_MASK         BIT(16)
> +#define MBOX_STATUS_ACK_MASK           BIT(0)
> +
> +/* Configuration and Status Registers */
> +#define REG_DB_IN              0x00
> +#define REG_DB_DIN0            0x04
> +#define REG_DB_DIN1            0x08
> +#define REG_DB_OUT             0x10
> +#define REG_DB_DOUT0           0x14
> +#define REG_DB_DOUT1           0x18
> +#define REG_DB_STAT            0x20
> +#define REG_DB_STATMASK                0x24
> +
> +struct slimpro_mbox_chan {
> +       struct device *dev;
> +       struct mbox_chan *chan;
> +       void __iomem *reg;
> +       int irq;
> +       u32 rx_msg[3];
> +};
> +
> +struct slimpro_mbox {
> +       struct mbox_controller mb_ctrl;
> +       struct slimpro_mbox_chan mc[MBOX_CNT];
> +       struct mbox_chan chans[MBOX_CNT];
> +};

The above two structure declaration could use kernel style documentation.

> +
> +static void mb_chan_send_msg(struct slimpro_mbox_chan *mb_chan, u32 *msg)
> +{
> +       writel(msg[1], mb_chan->reg + REG_DB_DOUT0);
> +       writel(msg[2], mb_chan->reg + REG_DB_DOUT1);
> +       writel(msg[0], mb_chan->reg + REG_DB_OUT);
> +}
> +
> +static void mb_chan_recv_msg(struct slimpro_mbox_chan *mb_chan)
> +{
> +       mb_chan->rx_msg[1] = readl(mb_chan->reg + REG_DB_DIN0);
> +       mb_chan->rx_msg[2] = readl(mb_chan->reg + REG_DB_DIN1);
> +       mb_chan->rx_msg[0] = readl(mb_chan->reg + REG_DB_IN);
> +}

Is there a requirement that operations in the above two functions be
ordered?  If not significant gains could be achieved by using
writel/readl_relaxed().  Same comment for the rest of this driver.

Thanks,
Mathieu

> +
> +static int mb_chan_status_ack(struct slimpro_mbox_chan *mb_chan)
> +{
> +       u32 val = readl(mb_chan->reg + REG_DB_STAT);
> +
> +       if (val & MBOX_STATUS_ACK_MASK) {
> +               writel(MBOX_STATUS_ACK_MASK, mb_chan->reg + REG_DB_STAT);
> +               return 1;
> +       }
> +       return 0;
> +}
> +
> +static int mb_chan_status_avail(struct slimpro_mbox_chan *mb_chan)
> +{
> +       u32 val = readl(mb_chan->reg + REG_DB_STAT);
> +
> +       if (val & MBOX_STATUS_AVAIL_MASK) {
> +               mb_chan_recv_msg(mb_chan);
> +               writel(MBOX_STATUS_AVAIL_MASK, mb_chan->reg + REG_DB_STAT);
> +               return 1;
> +       }
> +       return 0;
> +}
> +
> +static irqreturn_t slimpro_mbox_irq(int irq, void *id)
> +{
> +       struct slimpro_mbox_chan *mb_chan = id;
> +
> +       if (mb_chan_status_ack(mb_chan))
> +               mbox_chan_txdone(mb_chan->chan, 0);
> +
> +       if (mb_chan_status_avail(mb_chan))
> +               mbox_chan_received_data(mb_chan->chan, mb_chan->rx_msg);
> +
> +       return IRQ_HANDLED;
> +}
> +
> +static int slimpro_mbox_send_data(struct mbox_chan *chan, void *msg)
> +{
> +       struct slimpro_mbox_chan *mb_chan = chan->con_priv;
> +
> +       mb_chan_send_msg(mb_chan, msg);
> +       return 0;
> +}
> +
> +static int slimpro_mbox_startup(struct mbox_chan *chan)
> +{
> +       struct slimpro_mbox_chan *mb_chan = chan->con_priv;
> +       int rc;
> +       u32 val;
> +
> +       rc = devm_request_irq(mb_chan->dev, mb_chan->irq, slimpro_mbox_irq, 0,
> +                             MBOX_CON_NAME, mb_chan);
> +       if (unlikely(rc)) {
> +               dev_err(mb_chan->dev, "failed to register mailbox interrupt %d\n",
> +                       mb_chan->irq);
> +               return rc;
> +       }
> +
> +       /* Enable HW interrupt */
> +       writel(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK,
> +              mb_chan->reg + REG_DB_STAT);
> +       /* Unmask doorbell status interrupt */
> +       val = readl(mb_chan->reg + REG_DB_STATMASK);
> +       val &= ~(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
> +       writel(val, mb_chan->reg + REG_DB_STATMASK);
> +
> +       return 0;
> +}
> +
> +static void slimpro_mbox_shutdown(struct mbox_chan *chan)
> +{
> +       struct slimpro_mbox_chan *mb_chan = chan->con_priv;
> +       u32 val;
> +
> +       /* Mask doorbell status interrupt */
> +       val = readl(mb_chan->reg + REG_DB_STATMASK);
> +       val |= (MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
> +       writel(val, mb_chan->reg + REG_DB_STATMASK);
> +
> +       devm_free_irq(mb_chan->dev, mb_chan->irq, mb_chan);
> +}
> +
> +static struct mbox_chan_ops slimpro_mbox_ops = {
> +       .send_data = slimpro_mbox_send_data,
> +       .startup = slimpro_mbox_startup,
> +       .shutdown = slimpro_mbox_shutdown,
> +};
> +
> +static int slimpro_mbox_probe(struct platform_device *pdev)
> +{
> +       struct slimpro_mbox *ctx;
> +       struct resource *regs;
> +       void __iomem *mb_base;
> +       int rc;
> +       int i;
> +
> +       ctx = devm_kzalloc(&pdev->dev, sizeof(struct slimpro_mbox), GFP_KERNEL);
> +       if (IS_ERR(ctx))
> +               return PTR_ERR(ctx);
> +
> +       platform_set_drvdata(pdev, ctx);
> +
> +       regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       mb_base = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
> +       if (IS_ERR(mb_base))
> +               return PTR_ERR(mb_base);
> +
> +       /* Setup mailbox links */
> +       for (i = 0; i < MBOX_CNT; i++) {
> +               ctx->mc[i].irq = platform_get_irq(pdev, i);
> +               if (ctx->mc[i].irq < 0) {
> +                       if (i == 0) {
> +                               dev_err(&pdev->dev, "no available IRQ\n");
> +                               return -EINVAL;
> +                       }
> +                       dev_info(&pdev->dev, "no IRQ for channel %d\n", i);
> +                       break;
> +               }
> +
> +               ctx->mc[i].dev = &pdev->dev;
> +               ctx->mc[i].reg = mb_base + i * MBOX_REG_SET_OFFSET;
> +               ctx->mc[i].chan = &ctx->chans[i];
> +               ctx->chans[i].con_priv = &ctx->mc[i];
> +       }
> +
> +       /* Setup mailbox controller */
> +       ctx->mb_ctrl.dev = &pdev->dev;
> +       ctx->mb_ctrl.chans = ctx->chans;
> +       ctx->mb_ctrl.txdone_irq = true;
> +       ctx->mb_ctrl.ops = &slimpro_mbox_ops;
> +       ctx->mb_ctrl.num_chans = i;
> +
> +       rc = mbox_controller_register(&ctx->mb_ctrl);
> +       if (rc) {
> +               dev_err(&pdev->dev,
> +                       "APM X-Gene SLIMpro MailBox register failed:%d\n", rc);
> +               return rc;
> +       }
> +
> +       dev_info(&pdev->dev, "APM X-Gene SLIMpro MailBox registered\n");
> +       return 0;
> +}
> +
> +static int slimpro_mbox_remove(struct platform_device *pdev)
> +{
> +       struct slimpro_mbox *smb = platform_get_drvdata(pdev);
> +
> +       mbox_controller_unregister(&smb->mb_ctrl);
> +       return 0;
> +}
> +
> +static const struct of_device_id slimpro_of_match[] = {
> +       {.compatible = "apm,xgene-slimpro-mbox" },
> +       { },
> +};
> +MODULE_DEVICE_TABLE(of, slimpro_of_match);
> +
> +#ifdef CONFIG_ACPI
> +static const struct acpi_device_id slimpro_acpi_ids[] = {
> +       {"APMC0D01", 0},
> +       {}
> +};
> +MODULE_DEVICE_TABLE(acpi, slimpro_acpi_ids);
> +#endif
> +
> +static struct platform_driver slimpro_mbox_driver = {
> +       .probe  = slimpro_mbox_probe,
> +       .remove = slimpro_mbox_remove,
> +       .driver = {
> +               .name = "xgene-slimpro-mbox",
> +               .of_match_table = of_match_ptr(slimpro_of_match),
> +               .acpi_match_table = ACPI_PTR(slimpro_acpi_ids)
> +       },
> +};
> +
> +static int __init slimpro_mbox_init(void)
> +{
> +       return platform_driver_register(&slimpro_mbox_driver);
> +}
> +
> +static void __exit slimpro_mbox_exit(void)
> +{
> +       platform_driver_unregister(&slimpro_mbox_driver);
> +}
> +
> +subsys_initcall(slimpro_mbox_init);
> +module_exit(slimpro_mbox_exit);
> +
> +MODULE_DESCRIPTION("APM X-Gene SLIMpro Mailbox Driver");
> +MODULE_LICENSE("GPL");
> --
> 1.9.1
>
Duc Dang Feb. 10, 2016, 3:46 a.m. UTC | #2
On Tue, Feb 9, 2016 at 8:40 AM, Mathieu Poirier
<mathieu.poirier@linaro.org> wrote:
> On 8 February 2016 at 15:04, Duc Dang <dhdang@apm.com> wrote:
>> X-Gene mailbox controller provides 8 mailbox channels, with
>> each channel has a dedicated interrupt line.
>>
>> Signed-off-by: Feng Kan <fkan@apm.com>
>> Signed-off-by: Duc Dang <dhdang@apm.com>
>> ---
>> Changes since v4:
>>         - Rebase over v4.5-rc1
>>         - Fix section mistmatch warning by removing
>>         __init in slimpro_mbox_probe declaration
>>         - Correctly print channel number when
>>         there is no IRQ for that channel
>>
>> Changes since v3:
>>         - Rebase over v4.4
>>         - Remove 'id' in slimpro_mbox_chan structure
>>         - Remove small functions that are only called once
>>         and fold them into the other callers
>>         - Remove void* pointer type cast
>>         - Relax the number of mailbox IRQs condition
>>         - Use subsys_initcall to guarantee mailbox driver
>>         will be registered before any other dependent driver
>>         is loaded.
>>
>>  drivers/mailbox/Kconfig                 |   9 ++
>>  drivers/mailbox/Makefile                |   2 +
>>  drivers/mailbox/mailbox-xgene-slimpro.c | 264 ++++++++++++++++++++++++++++++++
>>  3 files changed, 275 insertions(+)
>>  create mode 100644 drivers/mailbox/mailbox-xgene-slimpro.c
>>
>> diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
>> index 546d05f..678e434 100644
>> --- a/drivers/mailbox/Kconfig
>> +++ b/drivers/mailbox/Kconfig
>> @@ -85,4 +85,13 @@ config MAILBOX_TEST
>>           Test client to help with testing new Controller driver
>>           implementations.
>>
>> +config XGENE_SLIMPRO_MBOX
>> +       tristate "APM SoC X-Gene SLIMpro Mailbox Controller"
>> +       depends on ARCH_XGENE
>> +       help
>> +         An implementation of the APM X-Gene Interprocessor Communication
>> +         Mailbox (IPCM) between the ARM 64-bit cores and SLIMpro controller.
>> +         It is used to send short messages between ARM64-bit cores and
>> +         the SLIMpro Management Engine, primarily for PM. Say Y here if you
>> +         want to use the APM X-Gene SLIMpro IPCM support.
>>  endif
>> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
>> index 92435ef..b602ef8 100644
>> --- a/drivers/mailbox/Makefile
>> +++ b/drivers/mailbox/Makefile
>> @@ -17,3 +17,5 @@ obj-$(CONFIG_ALTERA_MBOX)     += mailbox-altera.o
>>  obj-$(CONFIG_BCM2835_MBOX)     += bcm2835-mailbox.o
>>
>>  obj-$(CONFIG_STI_MBOX)         += mailbox-sti.o
>> +
>> +obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o
>> diff --git a/drivers/mailbox/mailbox-xgene-slimpro.c b/drivers/mailbox/mailbox-xgene-slimpro.c
>> new file mode 100644
>> index 0000000..0ea1eb8
>> --- /dev/null
>> +++ b/drivers/mailbox/mailbox-xgene-slimpro.c
>> @@ -0,0 +1,264 @@
>> +/*
>> + * APM X-Gene SLIMpro MailBox Driver
>> + *
>> + * Copyright (c) 2015, Applied Micro Circuits Corporation
>> + * Author: Feng Kan fkan@apm.com
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License as
>> + * published by the Free Software Foundation; either version 2 of
>> + * the License, or (at your option) any later version.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program; if not, see <http://www.gnu.org/licenses/>.
>> + *
>> + */
>> +#include <linux/acpi.h>
>> +#include <linux/delay.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/io.h>
>> +#include <linux/mailbox_controller.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/spinlock.h>
>> +
>> +#define MBOX_CON_NAME                  "slimpro-mbox"
>> +#define MBOX_REG_SET_OFFSET            0x1000
>> +#define MBOX_CNT                       8
>> +#define MBOX_STATUS_AVAIL_MASK         BIT(16)
>> +#define MBOX_STATUS_ACK_MASK           BIT(0)
>> +
>> +/* Configuration and Status Registers */
>> +#define REG_DB_IN              0x00
>> +#define REG_DB_DIN0            0x04
>> +#define REG_DB_DIN1            0x08
>> +#define REG_DB_OUT             0x10
>> +#define REG_DB_DOUT0           0x14
>> +#define REG_DB_DOUT1           0x18
>> +#define REG_DB_STAT            0x20
>> +#define REG_DB_STATMASK                0x24
>> +
>> +struct slimpro_mbox_chan {
>> +       struct device *dev;
>> +       struct mbox_chan *chan;
>> +       void __iomem *reg;
>> +       int irq;
>> +       u32 rx_msg[3];
>> +};
>> +
>> +struct slimpro_mbox {
>> +       struct mbox_controller mb_ctrl;
>> +       struct slimpro_mbox_chan mc[MBOX_CNT];
>> +       struct mbox_chan chans[MBOX_CNT];
>> +};
>
> The above two structure declaration could use kernel style documentation.

Can you please clarify or give an example? I looked into several files
in drivers/mailbox/ and drivers/irqchip but could not find what I need
to tweak.

>
>> +
>> +static void mb_chan_send_msg(struct slimpro_mbox_chan *mb_chan, u32 *msg)
>> +{
>> +       writel(msg[1], mb_chan->reg + REG_DB_DOUT0);
>> +       writel(msg[2], mb_chan->reg + REG_DB_DOUT1);
>> +       writel(msg[0], mb_chan->reg + REG_DB_OUT);
>> +}
>> +
>> +static void mb_chan_recv_msg(struct slimpro_mbox_chan *mb_chan)
>> +{
>> +       mb_chan->rx_msg[1] = readl(mb_chan->reg + REG_DB_DIN0);
>> +       mb_chan->rx_msg[2] = readl(mb_chan->reg + REG_DB_DIN1);
>> +       mb_chan->rx_msg[0] = readl(mb_chan->reg + REG_DB_IN);
>> +}
>
> Is there a requirement that operations in the above two functions be
> ordered?  If not significant gains could be achieved by using
> writel/readl_relaxed().  Same comment for the rest of this driver.

The 'writes' need to be in order as writing to REG_DB_OUT will trigger
interrupt, so I want the other 2 'writes' complete before it.

After the receiver get the message, it will clear door bell available
interrupt request, this will also trigger a door bell acknowledge
interrupt. So the 'read' to get the message and the 'write' to clear
the door bell available interrupt must be in order as well.

Regards,
Duc Dang.
>
> Thanks,
> Mathieu
>
>> +
>> +static int mb_chan_status_ack(struct slimpro_mbox_chan *mb_chan)
>> +{
>> +       u32 val = readl(mb_chan->reg + REG_DB_STAT);
>> +
>> +       if (val & MBOX_STATUS_ACK_MASK) {
>> +               writel(MBOX_STATUS_ACK_MASK, mb_chan->reg + REG_DB_STAT);
>> +               return 1;
>> +       }
>> +       return 0;
>> +}
>> +
>> +static int mb_chan_status_avail(struct slimpro_mbox_chan *mb_chan)
>> +{
>> +       u32 val = readl(mb_chan->reg + REG_DB_STAT);
>> +
>> +       if (val & MBOX_STATUS_AVAIL_MASK) {
>> +               mb_chan_recv_msg(mb_chan);
>> +               writel(MBOX_STATUS_AVAIL_MASK, mb_chan->reg + REG_DB_STAT);
>> +               return 1;
>> +       }
>> +       return 0;
>> +}
>> +
>> +static irqreturn_t slimpro_mbox_irq(int irq, void *id)
>> +{
>> +       struct slimpro_mbox_chan *mb_chan = id;
>> +
>> +       if (mb_chan_status_ack(mb_chan))
>> +               mbox_chan_txdone(mb_chan->chan, 0);
>> +
>> +       if (mb_chan_status_avail(mb_chan))
>> +               mbox_chan_received_data(mb_chan->chan, mb_chan->rx_msg);
>> +
>> +       return IRQ_HANDLED;
>> +}
>> +
>> +static int slimpro_mbox_send_data(struct mbox_chan *chan, void *msg)
>> +{
>> +       struct slimpro_mbox_chan *mb_chan = chan->con_priv;
>> +
>> +       mb_chan_send_msg(mb_chan, msg);
>> +       return 0;
>> +}
>> +
>> +static int slimpro_mbox_startup(struct mbox_chan *chan)
>> +{
>> +       struct slimpro_mbox_chan *mb_chan = chan->con_priv;
>> +       int rc;
>> +       u32 val;
>> +
>> +       rc = devm_request_irq(mb_chan->dev, mb_chan->irq, slimpro_mbox_irq, 0,
>> +                             MBOX_CON_NAME, mb_chan);
>> +       if (unlikely(rc)) {
>> +               dev_err(mb_chan->dev, "failed to register mailbox interrupt %d\n",
>> +                       mb_chan->irq);
>> +               return rc;
>> +       }
>> +
>> +       /* Enable HW interrupt */
>> +       writel(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK,
>> +              mb_chan->reg + REG_DB_STAT);
>> +       /* Unmask doorbell status interrupt */
>> +       val = readl(mb_chan->reg + REG_DB_STATMASK);
>> +       val &= ~(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
>> +       writel(val, mb_chan->reg + REG_DB_STATMASK);
>> +
>> +       return 0;
>> +}
>> +
>> +static void slimpro_mbox_shutdown(struct mbox_chan *chan)
>> +{
>> +       struct slimpro_mbox_chan *mb_chan = chan->con_priv;
>> +       u32 val;
>> +
>> +       /* Mask doorbell status interrupt */
>> +       val = readl(mb_chan->reg + REG_DB_STATMASK);
>> +       val |= (MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
>> +       writel(val, mb_chan->reg + REG_DB_STATMASK);
>> +
>> +       devm_free_irq(mb_chan->dev, mb_chan->irq, mb_chan);
>> +}
>> +
>> +static struct mbox_chan_ops slimpro_mbox_ops = {
>> +       .send_data = slimpro_mbox_send_data,
>> +       .startup = slimpro_mbox_startup,
>> +       .shutdown = slimpro_mbox_shutdown,
>> +};
>> +
>> +static int slimpro_mbox_probe(struct platform_device *pdev)
>> +{
>> +       struct slimpro_mbox *ctx;
>> +       struct resource *regs;
>> +       void __iomem *mb_base;
>> +       int rc;
>> +       int i;
>> +
>> +       ctx = devm_kzalloc(&pdev->dev, sizeof(struct slimpro_mbox), GFP_KERNEL);
>> +       if (IS_ERR(ctx))
>> +               return PTR_ERR(ctx);
>> +
>> +       platform_set_drvdata(pdev, ctx);
>> +
>> +       regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +       mb_base = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
>> +       if (IS_ERR(mb_base))
>> +               return PTR_ERR(mb_base);
>> +
>> +       /* Setup mailbox links */
>> +       for (i = 0; i < MBOX_CNT; i++) {
>> +               ctx->mc[i].irq = platform_get_irq(pdev, i);
>> +               if (ctx->mc[i].irq < 0) {
>> +                       if (i == 0) {
>> +                               dev_err(&pdev->dev, "no available IRQ\n");
>> +                               return -EINVAL;
>> +                       }
>> +                       dev_info(&pdev->dev, "no IRQ for channel %d\n", i);
>> +                       break;
>> +               }
>> +
>> +               ctx->mc[i].dev = &pdev->dev;
>> +               ctx->mc[i].reg = mb_base + i * MBOX_REG_SET_OFFSET;
>> +               ctx->mc[i].chan = &ctx->chans[i];
>> +               ctx->chans[i].con_priv = &ctx->mc[i];
>> +       }
>> +
>> +       /* Setup mailbox controller */
>> +       ctx->mb_ctrl.dev = &pdev->dev;
>> +       ctx->mb_ctrl.chans = ctx->chans;
>> +       ctx->mb_ctrl.txdone_irq = true;
>> +       ctx->mb_ctrl.ops = &slimpro_mbox_ops;
>> +       ctx->mb_ctrl.num_chans = i;
>> +
>> +       rc = mbox_controller_register(&ctx->mb_ctrl);
>> +       if (rc) {
>> +               dev_err(&pdev->dev,
>> +                       "APM X-Gene SLIMpro MailBox register failed:%d\n", rc);
>> +               return rc;
>> +       }
>> +
>> +       dev_info(&pdev->dev, "APM X-Gene SLIMpro MailBox registered\n");
>> +       return 0;
>> +}
>> +
>> +static int slimpro_mbox_remove(struct platform_device *pdev)
>> +{
>> +       struct slimpro_mbox *smb = platform_get_drvdata(pdev);
>> +
>> +       mbox_controller_unregister(&smb->mb_ctrl);
>> +       return 0;
>> +}
>> +
>> +static const struct of_device_id slimpro_of_match[] = {
>> +       {.compatible = "apm,xgene-slimpro-mbox" },
>> +       { },
>> +};
>> +MODULE_DEVICE_TABLE(of, slimpro_of_match);
>> +
>> +#ifdef CONFIG_ACPI
>> +static const struct acpi_device_id slimpro_acpi_ids[] = {
>> +       {"APMC0D01", 0},
>> +       {}
>> +};
>> +MODULE_DEVICE_TABLE(acpi, slimpro_acpi_ids);
>> +#endif
>> +
>> +static struct platform_driver slimpro_mbox_driver = {
>> +       .probe  = slimpro_mbox_probe,
>> +       .remove = slimpro_mbox_remove,
>> +       .driver = {
>> +               .name = "xgene-slimpro-mbox",
>> +               .of_match_table = of_match_ptr(slimpro_of_match),
>> +               .acpi_match_table = ACPI_PTR(slimpro_acpi_ids)
>> +       },
>> +};
>> +
>> +static int __init slimpro_mbox_init(void)
>> +{
>> +       return platform_driver_register(&slimpro_mbox_driver);
>> +}
>> +
>> +static void __exit slimpro_mbox_exit(void)
>> +{
>> +       platform_driver_unregister(&slimpro_mbox_driver);
>> +}
>> +
>> +subsys_initcall(slimpro_mbox_init);
>> +module_exit(slimpro_mbox_exit);
>> +
>> +MODULE_DESCRIPTION("APM X-Gene SLIMpro Mailbox Driver");
>> +MODULE_LICENSE("GPL");
>> --
>> 1.9.1
>>
Mathieu Poirier Feb. 10, 2016, 2:41 p.m. UTC | #3
On 9 February 2016 at 20:46, Duc Dang <dhdang@apm.com> wrote:
> On Tue, Feb 9, 2016 at 8:40 AM, Mathieu Poirier
> <mathieu.poirier@linaro.org> wrote:
>> On 8 February 2016 at 15:04, Duc Dang <dhdang@apm.com> wrote:
>>> X-Gene mailbox controller provides 8 mailbox channels, with
>>> each channel has a dedicated interrupt line.
>>>
>>> Signed-off-by: Feng Kan <fkan@apm.com>
>>> Signed-off-by: Duc Dang <dhdang@apm.com>
>>> ---
>>> Changes since v4:
>>>         - Rebase over v4.5-rc1
>>>         - Fix section mistmatch warning by removing
>>>         __init in slimpro_mbox_probe declaration
>>>         - Correctly print channel number when
>>>         there is no IRQ for that channel
>>>
>>> Changes since v3:
>>>         - Rebase over v4.4
>>>         - Remove 'id' in slimpro_mbox_chan structure
>>>         - Remove small functions that are only called once
>>>         and fold them into the other callers
>>>         - Remove void* pointer type cast
>>>         - Relax the number of mailbox IRQs condition
>>>         - Use subsys_initcall to guarantee mailbox driver
>>>         will be registered before any other dependent driver
>>>         is loaded.
>>>
>>>  drivers/mailbox/Kconfig                 |   9 ++
>>>  drivers/mailbox/Makefile                |   2 +
>>>  drivers/mailbox/mailbox-xgene-slimpro.c | 264 ++++++++++++++++++++++++++++++++
>>>  3 files changed, 275 insertions(+)
>>>  create mode 100644 drivers/mailbox/mailbox-xgene-slimpro.c
>>>
>>> diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
>>> index 546d05f..678e434 100644
>>> --- a/drivers/mailbox/Kconfig
>>> +++ b/drivers/mailbox/Kconfig
>>> @@ -85,4 +85,13 @@ config MAILBOX_TEST
>>>           Test client to help with testing new Controller driver
>>>           implementations.
>>>
>>> +config XGENE_SLIMPRO_MBOX
>>> +       tristate "APM SoC X-Gene SLIMpro Mailbox Controller"
>>> +       depends on ARCH_XGENE
>>> +       help
>>> +         An implementation of the APM X-Gene Interprocessor Communication
>>> +         Mailbox (IPCM) between the ARM 64-bit cores and SLIMpro controller.
>>> +         It is used to send short messages between ARM64-bit cores and
>>> +         the SLIMpro Management Engine, primarily for PM. Say Y here if you
>>> +         want to use the APM X-Gene SLIMpro IPCM support.
>>>  endif
>>> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
>>> index 92435ef..b602ef8 100644
>>> --- a/drivers/mailbox/Makefile
>>> +++ b/drivers/mailbox/Makefile
>>> @@ -17,3 +17,5 @@ obj-$(CONFIG_ALTERA_MBOX)     += mailbox-altera.o
>>>  obj-$(CONFIG_BCM2835_MBOX)     += bcm2835-mailbox.o
>>>
>>>  obj-$(CONFIG_STI_MBOX)         += mailbox-sti.o
>>> +
>>> +obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o
>>> diff --git a/drivers/mailbox/mailbox-xgene-slimpro.c b/drivers/mailbox/mailbox-xgene-slimpro.c
>>> new file mode 100644
>>> index 0000000..0ea1eb8
>>> --- /dev/null
>>> +++ b/drivers/mailbox/mailbox-xgene-slimpro.c
>>> @@ -0,0 +1,264 @@
>>> +/*
>>> + * APM X-Gene SLIMpro MailBox Driver
>>> + *
>>> + * Copyright (c) 2015, Applied Micro Circuits Corporation
>>> + * Author: Feng Kan fkan@apm.com
>>> + *
>>> + * This program is free software; you can redistribute it and/or
>>> + * modify it under the terms of the GNU General Public License as
>>> + * published by the Free Software Foundation; either version 2 of
>>> + * the License, or (at your option) any later version.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>>> + * GNU General Public License for more details.
>>> + *
>>> + * You should have received a copy of the GNU General Public License
>>> + * along with this program; if not, see <http://www.gnu.org/licenses/>.
>>> + *
>>> + */
>>> +#include <linux/acpi.h>
>>> +#include <linux/delay.h>
>>> +#include <linux/interrupt.h>
>>> +#include <linux/io.h>
>>> +#include <linux/mailbox_controller.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/spinlock.h>
>>> +
>>> +#define MBOX_CON_NAME                  "slimpro-mbox"
>>> +#define MBOX_REG_SET_OFFSET            0x1000
>>> +#define MBOX_CNT                       8
>>> +#define MBOX_STATUS_AVAIL_MASK         BIT(16)
>>> +#define MBOX_STATUS_ACK_MASK           BIT(0)
>>> +
>>> +/* Configuration and Status Registers */
>>> +#define REG_DB_IN              0x00
>>> +#define REG_DB_DIN0            0x04
>>> +#define REG_DB_DIN1            0x08
>>> +#define REG_DB_OUT             0x10
>>> +#define REG_DB_DOUT0           0x14
>>> +#define REG_DB_DOUT1           0x18
>>> +#define REG_DB_STAT            0x20
>>> +#define REG_DB_STATMASK                0x24
>>> +
>>> +struct slimpro_mbox_chan {
>>> +       struct device *dev;
>>> +       struct mbox_chan *chan;
>>> +       void __iomem *reg;
>>> +       int irq;
>>> +       u32 rx_msg[3];
>>> +};
>>> +
>>> +struct slimpro_mbox {
>>> +       struct mbox_controller mb_ctrl;
>>> +       struct slimpro_mbox_chan mc[MBOX_CNT];
>>> +       struct mbox_chan chans[MBOX_CNT];
>>> +};
>>
>> The above two structure declaration could use kernel style documentation.
>
> Can you please clarify or give an example? I looked into several files
> in drivers/mailbox/ and drivers/irqchip but could not find what I need
> to tweak.

http://lxr.free-electrons.com/source/drivers/mailbox/mailbox-sti.c#L42

>
>>
>>> +
>>> +static void mb_chan_send_msg(struct slimpro_mbox_chan *mb_chan, u32 *msg)
>>> +{
>>> +       writel(msg[1], mb_chan->reg + REG_DB_DOUT0);
>>> +       writel(msg[2], mb_chan->reg + REG_DB_DOUT1);
>>> +       writel(msg[0], mb_chan->reg + REG_DB_OUT);
>>> +}
>>> +
>>> +static void mb_chan_recv_msg(struct slimpro_mbox_chan *mb_chan)
>>> +{
>>> +       mb_chan->rx_msg[1] = readl(mb_chan->reg + REG_DB_DIN0);
>>> +       mb_chan->rx_msg[2] = readl(mb_chan->reg + REG_DB_DIN1);
>>> +       mb_chan->rx_msg[0] = readl(mb_chan->reg + REG_DB_IN);
>>> +}
>>
>> Is there a requirement that operations in the above two functions be
>> ordered?  If not significant gains could be achieved by using
>> writel/readl_relaxed().  Same comment for the rest of this driver.
>
> The 'writes' need to be in order as writing to REG_DB_OUT will trigger
> interrupt, so I want the other 2 'writes' complete before it.
>
> After the receiver get the message, it will clear door bell available
> interrupt request, this will also trigger a door bell acknowledge
> interrupt. So the 'read' to get the message and the 'write' to clear
> the door bell available interrupt must be in order as well.
>
> Regards,
> Duc Dang.
>>
>> Thanks,
>> Mathieu
>>
>>> +
>>> +static int mb_chan_status_ack(struct slimpro_mbox_chan *mb_chan)
>>> +{
>>> +       u32 val = readl(mb_chan->reg + REG_DB_STAT);
>>> +
>>> +       if (val & MBOX_STATUS_ACK_MASK) {
>>> +               writel(MBOX_STATUS_ACK_MASK, mb_chan->reg + REG_DB_STAT);
>>> +               return 1;
>>> +       }
>>> +       return 0;
>>> +}
>>> +
>>> +static int mb_chan_status_avail(struct slimpro_mbox_chan *mb_chan)
>>> +{
>>> +       u32 val = readl(mb_chan->reg + REG_DB_STAT);
>>> +
>>> +       if (val & MBOX_STATUS_AVAIL_MASK) {
>>> +               mb_chan_recv_msg(mb_chan);
>>> +               writel(MBOX_STATUS_AVAIL_MASK, mb_chan->reg + REG_DB_STAT);
>>> +               return 1;
>>> +       }
>>> +       return 0;
>>> +}
>>> +
>>> +static irqreturn_t slimpro_mbox_irq(int irq, void *id)
>>> +{
>>> +       struct slimpro_mbox_chan *mb_chan = id;
>>> +
>>> +       if (mb_chan_status_ack(mb_chan))
>>> +               mbox_chan_txdone(mb_chan->chan, 0);
>>> +
>>> +       if (mb_chan_status_avail(mb_chan))
>>> +               mbox_chan_received_data(mb_chan->chan, mb_chan->rx_msg);
>>> +
>>> +       return IRQ_HANDLED;
>>> +}
>>> +
>>> +static int slimpro_mbox_send_data(struct mbox_chan *chan, void *msg)
>>> +{
>>> +       struct slimpro_mbox_chan *mb_chan = chan->con_priv;
>>> +
>>> +       mb_chan_send_msg(mb_chan, msg);
>>> +       return 0;
>>> +}
>>> +
>>> +static int slimpro_mbox_startup(struct mbox_chan *chan)
>>> +{
>>> +       struct slimpro_mbox_chan *mb_chan = chan->con_priv;
>>> +       int rc;
>>> +       u32 val;
>>> +
>>> +       rc = devm_request_irq(mb_chan->dev, mb_chan->irq, slimpro_mbox_irq, 0,
>>> +                             MBOX_CON_NAME, mb_chan);
>>> +       if (unlikely(rc)) {
>>> +               dev_err(mb_chan->dev, "failed to register mailbox interrupt %d\n",
>>> +                       mb_chan->irq);
>>> +               return rc;
>>> +       }
>>> +
>>> +       /* Enable HW interrupt */
>>> +       writel(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK,
>>> +              mb_chan->reg + REG_DB_STAT);
>>> +       /* Unmask doorbell status interrupt */
>>> +       val = readl(mb_chan->reg + REG_DB_STATMASK);
>>> +       val &= ~(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
>>> +       writel(val, mb_chan->reg + REG_DB_STATMASK);
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +static void slimpro_mbox_shutdown(struct mbox_chan *chan)
>>> +{
>>> +       struct slimpro_mbox_chan *mb_chan = chan->con_priv;
>>> +       u32 val;
>>> +
>>> +       /* Mask doorbell status interrupt */
>>> +       val = readl(mb_chan->reg + REG_DB_STATMASK);
>>> +       val |= (MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
>>> +       writel(val, mb_chan->reg + REG_DB_STATMASK);
>>> +
>>> +       devm_free_irq(mb_chan->dev, mb_chan->irq, mb_chan);
>>> +}
>>> +
>>> +static struct mbox_chan_ops slimpro_mbox_ops = {
>>> +       .send_data = slimpro_mbox_send_data,
>>> +       .startup = slimpro_mbox_startup,
>>> +       .shutdown = slimpro_mbox_shutdown,
>>> +};
>>> +
>>> +static int slimpro_mbox_probe(struct platform_device *pdev)
>>> +{
>>> +       struct slimpro_mbox *ctx;
>>> +       struct resource *regs;
>>> +       void __iomem *mb_base;
>>> +       int rc;
>>> +       int i;
>>> +
>>> +       ctx = devm_kzalloc(&pdev->dev, sizeof(struct slimpro_mbox), GFP_KERNEL);
>>> +       if (IS_ERR(ctx))
>>> +               return PTR_ERR(ctx);
>>> +
>>> +       platform_set_drvdata(pdev, ctx);
>>> +
>>> +       regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> +       mb_base = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
>>> +       if (IS_ERR(mb_base))
>>> +               return PTR_ERR(mb_base);
>>> +
>>> +       /* Setup mailbox links */
>>> +       for (i = 0; i < MBOX_CNT; i++) {
>>> +               ctx->mc[i].irq = platform_get_irq(pdev, i);
>>> +               if (ctx->mc[i].irq < 0) {
>>> +                       if (i == 0) {
>>> +                               dev_err(&pdev->dev, "no available IRQ\n");
>>> +                               return -EINVAL;
>>> +                       }
>>> +                       dev_info(&pdev->dev, "no IRQ for channel %d\n", i);
>>> +                       break;
>>> +               }
>>> +
>>> +               ctx->mc[i].dev = &pdev->dev;
>>> +               ctx->mc[i].reg = mb_base + i * MBOX_REG_SET_OFFSET;
>>> +               ctx->mc[i].chan = &ctx->chans[i];
>>> +               ctx->chans[i].con_priv = &ctx->mc[i];
>>> +       }
>>> +
>>> +       /* Setup mailbox controller */
>>> +       ctx->mb_ctrl.dev = &pdev->dev;
>>> +       ctx->mb_ctrl.chans = ctx->chans;
>>> +       ctx->mb_ctrl.txdone_irq = true;
>>> +       ctx->mb_ctrl.ops = &slimpro_mbox_ops;
>>> +       ctx->mb_ctrl.num_chans = i;
>>> +
>>> +       rc = mbox_controller_register(&ctx->mb_ctrl);
>>> +       if (rc) {
>>> +               dev_err(&pdev->dev,
>>> +                       "APM X-Gene SLIMpro MailBox register failed:%d\n", rc);
>>> +               return rc;
>>> +       }
>>> +
>>> +       dev_info(&pdev->dev, "APM X-Gene SLIMpro MailBox registered\n");
>>> +       return 0;
>>> +}
>>> +
>>> +static int slimpro_mbox_remove(struct platform_device *pdev)
>>> +{
>>> +       struct slimpro_mbox *smb = platform_get_drvdata(pdev);
>>> +
>>> +       mbox_controller_unregister(&smb->mb_ctrl);
>>> +       return 0;
>>> +}
>>> +
>>> +static const struct of_device_id slimpro_of_match[] = {
>>> +       {.compatible = "apm,xgene-slimpro-mbox" },
>>> +       { },
>>> +};
>>> +MODULE_DEVICE_TABLE(of, slimpro_of_match);
>>> +
>>> +#ifdef CONFIG_ACPI
>>> +static const struct acpi_device_id slimpro_acpi_ids[] = {
>>> +       {"APMC0D01", 0},
>>> +       {}
>>> +};
>>> +MODULE_DEVICE_TABLE(acpi, slimpro_acpi_ids);
>>> +#endif
>>> +
>>> +static struct platform_driver slimpro_mbox_driver = {
>>> +       .probe  = slimpro_mbox_probe,
>>> +       .remove = slimpro_mbox_remove,
>>> +       .driver = {
>>> +               .name = "xgene-slimpro-mbox",
>>> +               .of_match_table = of_match_ptr(slimpro_of_match),
>>> +               .acpi_match_table = ACPI_PTR(slimpro_acpi_ids)
>>> +       },
>>> +};
>>> +
>>> +static int __init slimpro_mbox_init(void)
>>> +{
>>> +       return platform_driver_register(&slimpro_mbox_driver);
>>> +}
>>> +
>>> +static void __exit slimpro_mbox_exit(void)
>>> +{
>>> +       platform_driver_unregister(&slimpro_mbox_driver);
>>> +}
>>> +
>>> +subsys_initcall(slimpro_mbox_init);
>>> +module_exit(slimpro_mbox_exit);
>>> +
>>> +MODULE_DESCRIPTION("APM X-Gene SLIMpro Mailbox Driver");
>>> +MODULE_LICENSE("GPL");
>>> --
>>> 1.9.1
>>>
Duc Dang Feb. 13, 2016, 3:25 a.m. UTC | #4
On Wed, Feb 10, 2016 at 6:41 AM, Mathieu Poirier
<mathieu.poirier@linaro.org> wrote:
> On 9 February 2016 at 20:46, Duc Dang <dhdang@apm.com> wrote:
>> On Tue, Feb 9, 2016 at 8:40 AM, Mathieu Poirier
>> <mathieu.poirier@linaro.org> wrote:
>>> On 8 February 2016 at 15:04, Duc Dang <dhdang@apm.com> wrote:
>>>> X-Gene mailbox controller provides 8 mailbox channels, with
>>>> each channel has a dedicated interrupt line.
>>>>
>>>> Signed-off-by: Feng Kan <fkan@apm.com>
>>>> Signed-off-by: Duc Dang <dhdang@apm.com>
>>>> ---
>>>> Changes since v4:
>>>>         - Rebase over v4.5-rc1
>>>>         - Fix section mistmatch warning by removing
>>>>         __init in slimpro_mbox_probe declaration
>>>>         - Correctly print channel number when
>>>>         there is no IRQ for that channel
>>>>
>>>> Changes since v3:
>>>>         - Rebase over v4.4
>>>>         - Remove 'id' in slimpro_mbox_chan structure
>>>>         - Remove small functions that are only called once
>>>>         and fold them into the other callers
>>>>         - Remove void* pointer type cast
>>>>         - Relax the number of mailbox IRQs condition
>>>>         - Use subsys_initcall to guarantee mailbox driver
>>>>         will be registered before any other dependent driver
>>>>         is loaded.
>>>>
>>>>  drivers/mailbox/Kconfig                 |   9 ++
>>>>  drivers/mailbox/Makefile                |   2 +
>>>>  drivers/mailbox/mailbox-xgene-slimpro.c | 264 ++++++++++++++++++++++++++++++++
>>>>  3 files changed, 275 insertions(+)
>>>>  create mode 100644 drivers/mailbox/mailbox-xgene-slimpro.c
>>>>
>>>> diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
>>>> index 546d05f..678e434 100644
>>>> --- a/drivers/mailbox/Kconfig
>>>> +++ b/drivers/mailbox/Kconfig
>>>> @@ -85,4 +85,13 @@ config MAILBOX_TEST
>>>>           Test client to help with testing new Controller driver
>>>>           implementations.
>>>>
>>>> +config XGENE_SLIMPRO_MBOX
>>>> +       tristate "APM SoC X-Gene SLIMpro Mailbox Controller"
>>>> +       depends on ARCH_XGENE
>>>> +       help
>>>> +         An implementation of the APM X-Gene Interprocessor Communication
>>>> +         Mailbox (IPCM) between the ARM 64-bit cores and SLIMpro controller.
>>>> +         It is used to send short messages between ARM64-bit cores and
>>>> +         the SLIMpro Management Engine, primarily for PM. Say Y here if you
>>>> +         want to use the APM X-Gene SLIMpro IPCM support.
>>>>  endif
>>>> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
>>>> index 92435ef..b602ef8 100644
>>>> --- a/drivers/mailbox/Makefile
>>>> +++ b/drivers/mailbox/Makefile
>>>> @@ -17,3 +17,5 @@ obj-$(CONFIG_ALTERA_MBOX)     += mailbox-altera.o
>>>>  obj-$(CONFIG_BCM2835_MBOX)     += bcm2835-mailbox.o
>>>>
>>>>  obj-$(CONFIG_STI_MBOX)         += mailbox-sti.o
>>>> +
>>>> +obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o
>>>> diff --git a/drivers/mailbox/mailbox-xgene-slimpro.c b/drivers/mailbox/mailbox-xgene-slimpro.c
>>>> new file mode 100644
>>>> index 0000000..0ea1eb8
>>>> --- /dev/null
>>>> +++ b/drivers/mailbox/mailbox-xgene-slimpro.c
>>>> @@ -0,0 +1,264 @@
>>>> +/*
>>>> + * APM X-Gene SLIMpro MailBox Driver
>>>> + *
>>>> + * Copyright (c) 2015, Applied Micro Circuits Corporation
>>>> + * Author: Feng Kan fkan@apm.com
>>>> + *
>>>> + * This program is free software; you can redistribute it and/or
>>>> + * modify it under the terms of the GNU General Public License as
>>>> + * published by the Free Software Foundation; either version 2 of
>>>> + * the License, or (at your option) any later version.
>>>> + *
>>>> + * This program is distributed in the hope that it will be useful,
>>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>>>> + * GNU General Public License for more details.
>>>> + *
>>>> + * You should have received a copy of the GNU General Public License
>>>> + * along with this program; if not, see <http://www.gnu.org/licenses/>.
>>>> + *
>>>> + */
>>>> +#include <linux/acpi.h>
>>>> +#include <linux/delay.h>
>>>> +#include <linux/interrupt.h>
>>>> +#include <linux/io.h>
>>>> +#include <linux/mailbox_controller.h>
>>>> +#include <linux/module.h>
>>>> +#include <linux/of.h>
>>>> +#include <linux/platform_device.h>
>>>> +#include <linux/spinlock.h>
>>>> +
>>>> +#define MBOX_CON_NAME                  "slimpro-mbox"
>>>> +#define MBOX_REG_SET_OFFSET            0x1000
>>>> +#define MBOX_CNT                       8
>>>> +#define MBOX_STATUS_AVAIL_MASK         BIT(16)
>>>> +#define MBOX_STATUS_ACK_MASK           BIT(0)
>>>> +
>>>> +/* Configuration and Status Registers */
>>>> +#define REG_DB_IN              0x00
>>>> +#define REG_DB_DIN0            0x04
>>>> +#define REG_DB_DIN1            0x08
>>>> +#define REG_DB_OUT             0x10
>>>> +#define REG_DB_DOUT0           0x14
>>>> +#define REG_DB_DOUT1           0x18
>>>> +#define REG_DB_STAT            0x20
>>>> +#define REG_DB_STATMASK                0x24
>>>> +
>>>> +struct slimpro_mbox_chan {
>>>> +       struct device *dev;
>>>> +       struct mbox_chan *chan;
>>>> +       void __iomem *reg;
>>>> +       int irq;
>>>> +       u32 rx_msg[3];
>>>> +};
>>>> +
>>>> +struct slimpro_mbox {
>>>> +       struct mbox_controller mb_ctrl;
>>>> +       struct slimpro_mbox_chan mc[MBOX_CNT];
>>>> +       struct mbox_chan chans[MBOX_CNT];
>>>> +};
>>>
>>> The above two structure declaration could use kernel style documentation.
>>
>> Can you please clarify or give an example? I looked into several files
>> in drivers/mailbox/ and drivers/irqchip but could not find what I need
>> to tweak.
>
> http://lxr.free-electrons.com/source/drivers/mailbox/mailbox-sti.c#L42

I am modifying the structure defintion to add description and will
post a new version shortly.

Regards,
Duc Dang.
>
>>
>>>
>>>> +
>>>> +static void mb_chan_send_msg(struct slimpro_mbox_chan *mb_chan, u32 *msg)
>>>> +{
>>>> +       writel(msg[1], mb_chan->reg + REG_DB_DOUT0);
>>>> +       writel(msg[2], mb_chan->reg + REG_DB_DOUT1);
>>>> +       writel(msg[0], mb_chan->reg + REG_DB_OUT);
>>>> +}
>>>> +
>>>> +static void mb_chan_recv_msg(struct slimpro_mbox_chan *mb_chan)
>>>> +{
>>>> +       mb_chan->rx_msg[1] = readl(mb_chan->reg + REG_DB_DIN0);
>>>> +       mb_chan->rx_msg[2] = readl(mb_chan->reg + REG_DB_DIN1);
>>>> +       mb_chan->rx_msg[0] = readl(mb_chan->reg + REG_DB_IN);
>>>> +}
>>>
>>> Is there a requirement that operations in the above two functions be
>>> ordered?  If not significant gains could be achieved by using
>>> writel/readl_relaxed().  Same comment for the rest of this driver.
>>
>> The 'writes' need to be in order as writing to REG_DB_OUT will trigger
>> interrupt, so I want the other 2 'writes' complete before it.
>>
>> After the receiver get the message, it will clear door bell available
>> interrupt request, this will also trigger a door bell acknowledge
>> interrupt. So the 'read' to get the message and the 'write' to clear
>> the door bell available interrupt must be in order as well.
>>
>> Regards,
>> Duc Dang.
>>>
>>> Thanks,
>>> Mathieu
>>>
>>>> +
>>>> +static int mb_chan_status_ack(struct slimpro_mbox_chan *mb_chan)
>>>> +{
>>>> +       u32 val = readl(mb_chan->reg + REG_DB_STAT);
>>>> +
>>>> +       if (val & MBOX_STATUS_ACK_MASK) {
>>>> +               writel(MBOX_STATUS_ACK_MASK, mb_chan->reg + REG_DB_STAT);
>>>> +               return 1;
>>>> +       }
>>>> +       return 0;
>>>> +}
>>>> +
>>>> +static int mb_chan_status_avail(struct slimpro_mbox_chan *mb_chan)
>>>> +{
>>>> +       u32 val = readl(mb_chan->reg + REG_DB_STAT);
>>>> +
>>>> +       if (val & MBOX_STATUS_AVAIL_MASK) {
>>>> +               mb_chan_recv_msg(mb_chan);
>>>> +               writel(MBOX_STATUS_AVAIL_MASK, mb_chan->reg + REG_DB_STAT);
>>>> +               return 1;
>>>> +       }
>>>> +       return 0;
>>>> +}
>>>> +
>>>> +static irqreturn_t slimpro_mbox_irq(int irq, void *id)
>>>> +{
>>>> +       struct slimpro_mbox_chan *mb_chan = id;
>>>> +
>>>> +       if (mb_chan_status_ack(mb_chan))
>>>> +               mbox_chan_txdone(mb_chan->chan, 0);
>>>> +
>>>> +       if (mb_chan_status_avail(mb_chan))
>>>> +               mbox_chan_received_data(mb_chan->chan, mb_chan->rx_msg);
>>>> +
>>>> +       return IRQ_HANDLED;
>>>> +}
>>>> +
>>>> +static int slimpro_mbox_send_data(struct mbox_chan *chan, void *msg)
>>>> +{
>>>> +       struct slimpro_mbox_chan *mb_chan = chan->con_priv;
>>>> +
>>>> +       mb_chan_send_msg(mb_chan, msg);
>>>> +       return 0;
>>>> +}
>>>> +
>>>> +static int slimpro_mbox_startup(struct mbox_chan *chan)
>>>> +{
>>>> +       struct slimpro_mbox_chan *mb_chan = chan->con_priv;
>>>> +       int rc;
>>>> +       u32 val;
>>>> +
>>>> +       rc = devm_request_irq(mb_chan->dev, mb_chan->irq, slimpro_mbox_irq, 0,
>>>> +                             MBOX_CON_NAME, mb_chan);
>>>> +       if (unlikely(rc)) {
>>>> +               dev_err(mb_chan->dev, "failed to register mailbox interrupt %d\n",
>>>> +                       mb_chan->irq);
>>>> +               return rc;
>>>> +       }
>>>> +
>>>> +       /* Enable HW interrupt */
>>>> +       writel(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK,
>>>> +              mb_chan->reg + REG_DB_STAT);
>>>> +       /* Unmask doorbell status interrupt */
>>>> +       val = readl(mb_chan->reg + REG_DB_STATMASK);
>>>> +       val &= ~(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
>>>> +       writel(val, mb_chan->reg + REG_DB_STATMASK);
>>>> +
>>>> +       return 0;
>>>> +}
>>>> +
>>>> +static void slimpro_mbox_shutdown(struct mbox_chan *chan)
>>>> +{
>>>> +       struct slimpro_mbox_chan *mb_chan = chan->con_priv;
>>>> +       u32 val;
>>>> +
>>>> +       /* Mask doorbell status interrupt */
>>>> +       val = readl(mb_chan->reg + REG_DB_STATMASK);
>>>> +       val |= (MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
>>>> +       writel(val, mb_chan->reg + REG_DB_STATMASK);
>>>> +
>>>> +       devm_free_irq(mb_chan->dev, mb_chan->irq, mb_chan);
>>>> +}
>>>> +
>>>> +static struct mbox_chan_ops slimpro_mbox_ops = {
>>>> +       .send_data = slimpro_mbox_send_data,
>>>> +       .startup = slimpro_mbox_startup,
>>>> +       .shutdown = slimpro_mbox_shutdown,
>>>> +};
>>>> +
>>>> +static int slimpro_mbox_probe(struct platform_device *pdev)
>>>> +{
>>>> +       struct slimpro_mbox *ctx;
>>>> +       struct resource *regs;
>>>> +       void __iomem *mb_base;
>>>> +       int rc;
>>>> +       int i;
>>>> +
>>>> +       ctx = devm_kzalloc(&pdev->dev, sizeof(struct slimpro_mbox), GFP_KERNEL);
>>>> +       if (IS_ERR(ctx))
>>>> +               return PTR_ERR(ctx);
>>>> +
>>>> +       platform_set_drvdata(pdev, ctx);
>>>> +
>>>> +       regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>>> +       mb_base = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
>>>> +       if (IS_ERR(mb_base))
>>>> +               return PTR_ERR(mb_base);
>>>> +
>>>> +       /* Setup mailbox links */
>>>> +       for (i = 0; i < MBOX_CNT; i++) {
>>>> +               ctx->mc[i].irq = platform_get_irq(pdev, i);
>>>> +               if (ctx->mc[i].irq < 0) {
>>>> +                       if (i == 0) {
>>>> +                               dev_err(&pdev->dev, "no available IRQ\n");
>>>> +                               return -EINVAL;
>>>> +                       }
>>>> +                       dev_info(&pdev->dev, "no IRQ for channel %d\n", i);
>>>> +                       break;
>>>> +               }
>>>> +
>>>> +               ctx->mc[i].dev = &pdev->dev;
>>>> +               ctx->mc[i].reg = mb_base + i * MBOX_REG_SET_OFFSET;
>>>> +               ctx->mc[i].chan = &ctx->chans[i];
>>>> +               ctx->chans[i].con_priv = &ctx->mc[i];
>>>> +       }
>>>> +
>>>> +       /* Setup mailbox controller */
>>>> +       ctx->mb_ctrl.dev = &pdev->dev;
>>>> +       ctx->mb_ctrl.chans = ctx->chans;
>>>> +       ctx->mb_ctrl.txdone_irq = true;
>>>> +       ctx->mb_ctrl.ops = &slimpro_mbox_ops;
>>>> +       ctx->mb_ctrl.num_chans = i;
>>>> +
>>>> +       rc = mbox_controller_register(&ctx->mb_ctrl);
>>>> +       if (rc) {
>>>> +               dev_err(&pdev->dev,
>>>> +                       "APM X-Gene SLIMpro MailBox register failed:%d\n", rc);
>>>> +               return rc;
>>>> +       }
>>>> +
>>>> +       dev_info(&pdev->dev, "APM X-Gene SLIMpro MailBox registered\n");
>>>> +       return 0;
>>>> +}
>>>> +
>>>> +static int slimpro_mbox_remove(struct platform_device *pdev)
>>>> +{
>>>> +       struct slimpro_mbox *smb = platform_get_drvdata(pdev);
>>>> +
>>>> +       mbox_controller_unregister(&smb->mb_ctrl);
>>>> +       return 0;
>>>> +}
>>>> +
>>>> +static const struct of_device_id slimpro_of_match[] = {
>>>> +       {.compatible = "apm,xgene-slimpro-mbox" },
>>>> +       { },
>>>> +};
>>>> +MODULE_DEVICE_TABLE(of, slimpro_of_match);
>>>> +
>>>> +#ifdef CONFIG_ACPI
>>>> +static const struct acpi_device_id slimpro_acpi_ids[] = {
>>>> +       {"APMC0D01", 0},
>>>> +       {}
>>>> +};
>>>> +MODULE_DEVICE_TABLE(acpi, slimpro_acpi_ids);
>>>> +#endif
>>>> +
>>>> +static struct platform_driver slimpro_mbox_driver = {
>>>> +       .probe  = slimpro_mbox_probe,
>>>> +       .remove = slimpro_mbox_remove,
>>>> +       .driver = {
>>>> +               .name = "xgene-slimpro-mbox",
>>>> +               .of_match_table = of_match_ptr(slimpro_of_match),
>>>> +               .acpi_match_table = ACPI_PTR(slimpro_acpi_ids)
>>>> +       },
>>>> +};
>>>> +
>>>> +static int __init slimpro_mbox_init(void)
>>>> +{
>>>> +       return platform_driver_register(&slimpro_mbox_driver);
>>>> +}
>>>> +
>>>> +static void __exit slimpro_mbox_exit(void)
>>>> +{
>>>> +       platform_driver_unregister(&slimpro_mbox_driver);
>>>> +}
>>>> +
>>>> +subsys_initcall(slimpro_mbox_init);
>>>> +module_exit(slimpro_mbox_exit);
>>>> +
>>>> +MODULE_DESCRIPTION("APM X-Gene SLIMpro Mailbox Driver");
>>>> +MODULE_LICENSE("GPL");
>>>> --
>>>> 1.9.1
>>>>
Duc Dang Feb. 13, 2016, 3:39 a.m. UTC | #5
APM X-Gene SoC has a mailbox controller that provides
communication mechanism for X-Gene Arm64 cores to communicate
with X-Gene SoC's Cortex M3 (SLIMpro) processor.

X-Gene mailbox controller provides 8 mailbox channels, with
each channel has a dedicated interrupt line.

Changes since v5:
	- Add more description into SlimPRO
	mailbox data structure

Changes since v4:
        - Rebase over v4.5-rc1
        - Fix section mismatch warning during compiling
        - Correctly print channel number when there is
        no IRQ for that channel
        - Change node name to mailbox@10540000
	- Correct the number of IRQs in documentation

Changes since v3:
        - Rebase over v4.4
        - Remove 'id' in slimpro_mbox_chan structure
        - Remove functions that are only called once
        and fold them into the other callers
        - Remove void* pointer type cast
        - Relax the number of mailbox IRQs condition
        - Fix error and address comment in documentation
        (xgene-slimpro-mailbox.txt)

Changes since v2:
        - Rebase Feng's patch set over v4.3-rc5
        - Remove uneccessary 'inline' in function definition
        - Use module_platform_driver instead of subsys_initcall
        - Minor coding stype clean up

Changes since v1:
        - Add ACPI support
        - Use defines for reg offset

Duc Dang (3):
  mailbox: Add support for APM X-Gene platform mailbox driver
  Documentation: mailbox: Add APM X-Gene SLIMpro mailbox dts
    documentation
  arm64: dts: mailbox device tree node for APM X-Gene platform.

 .../bindings/mailbox/xgene-slimpro-mailbox.txt     |  35 +++
 arch/arm64/boot/dts/apm/apm-storm.dtsi             |  14 +
 drivers/mailbox/Kconfig                            |   9 +
 drivers/mailbox/Makefile                           |   2 +
 drivers/mailbox/mailbox-xgene-slimpro.c            | 284 +++++++++++++++++++++
 5 files changed, 344 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mailbox/xgene-slimpro-mailbox.txt
 create mode 100644 drivers/mailbox/mailbox-xgene-slimpro.c
Duc Dang Feb. 19, 2016, 8:43 p.m. UTC | #6
On Fri, Feb 12, 2016 at 7:39 PM, Duc Dang <dhdang@apm.com> wrote:
> APM X-Gene SoC has a mailbox controller that provides
> communication mechanism for X-Gene Arm64 cores to communicate
> with X-Gene SoC's Cortex M3 (SLIMpro) processor.
>
> X-Gene mailbox controller provides 8 mailbox channels, with
> each channel has a dedicated interrupt line.

Hi Jassi,

Are you fine with this version of the patch?

Regards,
Duc Dang.
>
> Changes since v5:
>         - Add more description into SlimPRO
>         mailbox data structure
>
> Changes since v4:
>         - Rebase over v4.5-rc1
>         - Fix section mismatch warning during compiling
>         - Correctly print channel number when there is
>         no IRQ for that channel
>         - Change node name to mailbox@10540000
>         - Correct the number of IRQs in documentation
>
> Changes since v3:
>         - Rebase over v4.4
>         - Remove 'id' in slimpro_mbox_chan structure
>         - Remove functions that are only called once
>         and fold them into the other callers
>         - Remove void* pointer type cast
>         - Relax the number of mailbox IRQs condition
>         - Fix error and address comment in documentation
>         (xgene-slimpro-mailbox.txt)
>
> Changes since v2:
>         - Rebase Feng's patch set over v4.3-rc5
>         - Remove uneccessary 'inline' in function definition
>         - Use module_platform_driver instead of subsys_initcall
>         - Minor coding stype clean up
>
> Changes since v1:
>         - Add ACPI support
>         - Use defines for reg offset
>
> Duc Dang (3):
>   mailbox: Add support for APM X-Gene platform mailbox driver
>   Documentation: mailbox: Add APM X-Gene SLIMpro mailbox dts
>     documentation
>   arm64: dts: mailbox device tree node for APM X-Gene platform.
>
>  .../bindings/mailbox/xgene-slimpro-mailbox.txt     |  35 +++
>  arch/arm64/boot/dts/apm/apm-storm.dtsi             |  14 +
>  drivers/mailbox/Kconfig                            |   9 +
>  drivers/mailbox/Makefile                           |   2 +
>  drivers/mailbox/mailbox-xgene-slimpro.c            | 284 +++++++++++++++++++++
>  5 files changed, 344 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mailbox/xgene-slimpro-mailbox.txt
>  create mode 100644 drivers/mailbox/mailbox-xgene-slimpro.c
>
> --
> 1.9.1
>
diff mbox

Patch

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 546d05f..678e434 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -85,4 +85,13 @@  config MAILBOX_TEST
 	  Test client to help with testing new Controller driver
 	  implementations.
 
+config XGENE_SLIMPRO_MBOX
+	tristate "APM SoC X-Gene SLIMpro Mailbox Controller"
+	depends on ARCH_XGENE
+	help
+	  An implementation of the APM X-Gene Interprocessor Communication
+	  Mailbox (IPCM) between the ARM 64-bit cores and SLIMpro controller.
+	  It is used to send short messages between ARM64-bit cores and
+	  the SLIMpro Management Engine, primarily for PM. Say Y here if you
+	  want to use the APM X-Gene SLIMpro IPCM support.
 endif
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 92435ef..b602ef8 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -17,3 +17,5 @@  obj-$(CONFIG_ALTERA_MBOX)	+= mailbox-altera.o
 obj-$(CONFIG_BCM2835_MBOX)	+= bcm2835-mailbox.o
 
 obj-$(CONFIG_STI_MBOX)		+= mailbox-sti.o
+
+obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o
diff --git a/drivers/mailbox/mailbox-xgene-slimpro.c b/drivers/mailbox/mailbox-xgene-slimpro.c
new file mode 100644
index 0000000..0ea1eb8
--- /dev/null
+++ b/drivers/mailbox/mailbox-xgene-slimpro.c
@@ -0,0 +1,264 @@ 
+/*
+ * APM X-Gene SLIMpro MailBox Driver
+ *
+ * Copyright (c) 2015, Applied Micro Circuits Corporation
+ * Author: Feng Kan fkan@apm.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+
+#define MBOX_CON_NAME			"slimpro-mbox"
+#define MBOX_REG_SET_OFFSET		0x1000
+#define MBOX_CNT			8
+#define MBOX_STATUS_AVAIL_MASK		BIT(16)
+#define MBOX_STATUS_ACK_MASK		BIT(0)
+
+/* Configuration and Status Registers */
+#define REG_DB_IN		0x00
+#define REG_DB_DIN0		0x04
+#define REG_DB_DIN1		0x08
+#define REG_DB_OUT		0x10
+#define REG_DB_DOUT0		0x14
+#define REG_DB_DOUT1		0x18
+#define REG_DB_STAT		0x20
+#define REG_DB_STATMASK		0x24
+
+struct slimpro_mbox_chan {
+	struct device *dev;
+	struct mbox_chan *chan;
+	void __iomem *reg;
+	int irq;
+	u32 rx_msg[3];
+};
+
+struct slimpro_mbox {
+	struct mbox_controller mb_ctrl;
+	struct slimpro_mbox_chan mc[MBOX_CNT];
+	struct mbox_chan chans[MBOX_CNT];
+};
+
+static void mb_chan_send_msg(struct slimpro_mbox_chan *mb_chan, u32 *msg)
+{
+	writel(msg[1], mb_chan->reg + REG_DB_DOUT0);
+	writel(msg[2], mb_chan->reg + REG_DB_DOUT1);
+	writel(msg[0], mb_chan->reg + REG_DB_OUT);
+}
+
+static void mb_chan_recv_msg(struct slimpro_mbox_chan *mb_chan)
+{
+	mb_chan->rx_msg[1] = readl(mb_chan->reg + REG_DB_DIN0);
+	mb_chan->rx_msg[2] = readl(mb_chan->reg + REG_DB_DIN1);
+	mb_chan->rx_msg[0] = readl(mb_chan->reg + REG_DB_IN);
+}
+
+static int mb_chan_status_ack(struct slimpro_mbox_chan *mb_chan)
+{
+	u32 val = readl(mb_chan->reg + REG_DB_STAT);
+
+	if (val & MBOX_STATUS_ACK_MASK) {
+		writel(MBOX_STATUS_ACK_MASK, mb_chan->reg + REG_DB_STAT);
+		return 1;
+	}
+	return 0;
+}
+
+static int mb_chan_status_avail(struct slimpro_mbox_chan *mb_chan)
+{
+	u32 val = readl(mb_chan->reg + REG_DB_STAT);
+
+	if (val & MBOX_STATUS_AVAIL_MASK) {
+		mb_chan_recv_msg(mb_chan);
+		writel(MBOX_STATUS_AVAIL_MASK, mb_chan->reg + REG_DB_STAT);
+		return 1;
+	}
+	return 0;
+}
+
+static irqreturn_t slimpro_mbox_irq(int irq, void *id)
+{
+	struct slimpro_mbox_chan *mb_chan = id;
+
+	if (mb_chan_status_ack(mb_chan))
+		mbox_chan_txdone(mb_chan->chan, 0);
+
+	if (mb_chan_status_avail(mb_chan))
+		mbox_chan_received_data(mb_chan->chan, mb_chan->rx_msg);
+
+	return IRQ_HANDLED;
+}
+
+static int slimpro_mbox_send_data(struct mbox_chan *chan, void *msg)
+{
+	struct slimpro_mbox_chan *mb_chan = chan->con_priv;
+
+	mb_chan_send_msg(mb_chan, msg);
+	return 0;
+}
+
+static int slimpro_mbox_startup(struct mbox_chan *chan)
+{
+	struct slimpro_mbox_chan *mb_chan = chan->con_priv;
+	int rc;
+	u32 val;
+
+	rc = devm_request_irq(mb_chan->dev, mb_chan->irq, slimpro_mbox_irq, 0,
+			      MBOX_CON_NAME, mb_chan);
+	if (unlikely(rc)) {
+		dev_err(mb_chan->dev, "failed to register mailbox interrupt %d\n",
+			mb_chan->irq);
+		return rc;
+	}
+
+	/* Enable HW interrupt */
+	writel(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK,
+	       mb_chan->reg + REG_DB_STAT);
+	/* Unmask doorbell status interrupt */
+	val = readl(mb_chan->reg + REG_DB_STATMASK);
+	val &= ~(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
+	writel(val, mb_chan->reg + REG_DB_STATMASK);
+
+	return 0;
+}
+
+static void slimpro_mbox_shutdown(struct mbox_chan *chan)
+{
+	struct slimpro_mbox_chan *mb_chan = chan->con_priv;
+	u32 val;
+
+	/* Mask doorbell status interrupt */
+	val = readl(mb_chan->reg + REG_DB_STATMASK);
+	val |= (MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
+	writel(val, mb_chan->reg + REG_DB_STATMASK);
+
+	devm_free_irq(mb_chan->dev, mb_chan->irq, mb_chan);
+}
+
+static struct mbox_chan_ops slimpro_mbox_ops = {
+	.send_data = slimpro_mbox_send_data,
+	.startup = slimpro_mbox_startup,
+	.shutdown = slimpro_mbox_shutdown,
+};
+
+static int slimpro_mbox_probe(struct platform_device *pdev)
+{
+	struct slimpro_mbox *ctx;
+	struct resource *regs;
+	void __iomem *mb_base;
+	int rc;
+	int i;
+
+	ctx = devm_kzalloc(&pdev->dev, sizeof(struct slimpro_mbox), GFP_KERNEL);
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
+
+	platform_set_drvdata(pdev, ctx);
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mb_base = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
+	if (IS_ERR(mb_base))
+		return PTR_ERR(mb_base);
+
+	/* Setup mailbox links */
+	for (i = 0; i < MBOX_CNT; i++) {
+		ctx->mc[i].irq = platform_get_irq(pdev, i);
+		if (ctx->mc[i].irq < 0) {
+			if (i == 0) {
+				dev_err(&pdev->dev, "no available IRQ\n");
+				return -EINVAL;
+			}
+			dev_info(&pdev->dev, "no IRQ for channel %d\n", i);
+			break;
+		}
+
+		ctx->mc[i].dev = &pdev->dev;
+		ctx->mc[i].reg = mb_base + i * MBOX_REG_SET_OFFSET;
+		ctx->mc[i].chan = &ctx->chans[i];
+		ctx->chans[i].con_priv = &ctx->mc[i];
+	}
+
+	/* Setup mailbox controller */
+	ctx->mb_ctrl.dev = &pdev->dev;
+	ctx->mb_ctrl.chans = ctx->chans;
+	ctx->mb_ctrl.txdone_irq = true;
+	ctx->mb_ctrl.ops = &slimpro_mbox_ops;
+	ctx->mb_ctrl.num_chans = i;
+
+	rc = mbox_controller_register(&ctx->mb_ctrl);
+	if (rc) {
+		dev_err(&pdev->dev,
+			"APM X-Gene SLIMpro MailBox register failed:%d\n", rc);
+		return rc;
+	}
+
+	dev_info(&pdev->dev, "APM X-Gene SLIMpro MailBox registered\n");
+	return 0;
+}
+
+static int slimpro_mbox_remove(struct platform_device *pdev)
+{
+	struct slimpro_mbox *smb = platform_get_drvdata(pdev);
+
+	mbox_controller_unregister(&smb->mb_ctrl);
+	return 0;
+}
+
+static const struct of_device_id slimpro_of_match[] = {
+	{.compatible = "apm,xgene-slimpro-mbox" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, slimpro_of_match);
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id slimpro_acpi_ids[] = {
+	{"APMC0D01", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, slimpro_acpi_ids);
+#endif
+
+static struct platform_driver slimpro_mbox_driver = {
+	.probe	= slimpro_mbox_probe,
+	.remove = slimpro_mbox_remove,
+	.driver	= {
+		.name = "xgene-slimpro-mbox",
+		.of_match_table = of_match_ptr(slimpro_of_match),
+		.acpi_match_table = ACPI_PTR(slimpro_acpi_ids)
+	},
+};
+
+static int __init slimpro_mbox_init(void)
+{
+	return platform_driver_register(&slimpro_mbox_driver);
+}
+
+static void __exit slimpro_mbox_exit(void)
+{
+	platform_driver_unregister(&slimpro_mbox_driver);
+}
+
+subsys_initcall(slimpro_mbox_init);
+module_exit(slimpro_mbox_exit);
+
+MODULE_DESCRIPTION("APM X-Gene SLIMpro Mailbox Driver");
+MODULE_LICENSE("GPL");