diff mbox series

[v11,10/10] tty: serial: Add Nuvoton ma35d1 serial driver support

Message ID 20230516075217.205401-11-ychuang570808@gmail.com (mailing list archive)
State New, archived
Headers show
Series Introduce Nuvoton ma35d1 SoC | expand

Commit Message

Jacky Huang May 16, 2023, 7:52 a.m. UTC
From: Jacky Huang <ychuang3@nuvoton.com>

This adds UART and console driver for Nuvoton ma35d1 Soc.
It supports full-duplex communication, FIFO control, and
hardware flow control.

Signed-off-by: Jacky Huang <ychuang3@nuvoton.com>
---
 drivers/tty/serial/Kconfig         |  18 +
 drivers/tty/serial/Makefile        |   1 +
 drivers/tty/serial/ma35d1_serial.c | 800 +++++++++++++++++++++++++++++
 3 files changed, 819 insertions(+)
 create mode 100644 drivers/tty/serial/ma35d1_serial.c

Comments

Jiri Slaby May 24, 2023, 7:42 a.m. UTC | #1
On 16. 05. 23, 9:52, Jacky Huang wrote:
> +static void ma35d1serial_config_port(struct uart_port *port, int flags)
> +{
> +	/*
> +	 * Driver core for serial ports forces a non-zero value for port type.
> +	 * Write an arbitrary value here to accommodate the serial core driver,
> +	 * as ID part of UAPI is redundant.
> +	 */
> +	port->type = 1;

So this 1 translates to PORT_8250. Why not to use it directly? Or 
something more saner like PORT_16550A?

> +}
> +
> +static int ma35d1serial_verify_port(struct uart_port *port, struct serial_struct *ser)
> +{
> +	if (port->type != PORT_UNKNOWN && ser->type != 1)
> +		return -EINVAL;
> +
> +	return 0;
> +}
...
> +static int __init ma35d1serial_console_setup(struct console *co, char *options)
> +{
> +	struct device_node *np = ma35d1serial_uart_nodes[co->index];
> +	struct uart_ma35d1_port *p = &ma35d1serial_ports[co->index];
> +	u32 val32[4];
> +	struct uart_port *port;
> +	int baud = 115200;
> +	int bits = 8;
> +	int parity = 'n';
> +	int flow = 'n';
> +
> +	/*
> +	 * Check whether an invalid uart number has been specified, and

You dereferenced ma35d1serial_uart_nodes already. Doesn't 
console=ttyNVT1000 (or something like that) crash the system?

> +	 * if so, search for the first available port that does have
> +	 * console support.

The code below doesn't match this comment.

> +	 */
> +	if ((co->index < 0) || (co->index >= MA35_UART_NR)) {
> +		pr_debug("Console Port%x out of range\n", co->index);
> +		return -EINVAL;
> +	}
> +
> +	if (of_property_read_u32_array(np, "reg", val32, 4) != 0)

Shouldn't that 4 be ARRAY_SIZE(val32) instead?

> +		return -EINVAL;

One \n here please.

> +	p->port.iobase = val32[1];
> +	p->port.membase = ioremap(p->port.iobase, MA35_UART_REG_SIZE);

What if this fails?

> +	p->port.ops = &ma35d1serial_ops;
> +	p->port.line = 0;
> +	p->port.uartclk = MA35_UART_CONSOLE_CLK;
> +
> +	port = &ma35d1serial_ports[co->index].port;

Isn't this:
   port = &p->port;
?

Either use port on all above lines or drop the "port" variable 
completely and use "p->port" below instead.

> +
> +	if (options)
> +		uart_parse_options(options, &baud, &parity, &bits, &flow);
> +
> +	return uart_set_options(port, co, baud, parity, bits, flow);
> +}
> +
> +static struct console ma35d1serial_console = {
> +	.name    = "ttyNVT",
> +	.write   = ma35d1serial_console_write,
> +	.device  = uart_console_device,
> +	.setup   = ma35d1serial_console_setup,
> +	.flags   = CON_PRINTBUFFER | CON_ENABLED,
> +	.index   = -1,
> +	.data    = &ma35d1serial_reg,

I don't see console->data used anywhere in the driver?

> +};
...
> +static int ma35d1serial_probe(struct platform_device *pdev)
> +{
> +	struct resource *res_mem;
> +	struct uart_ma35d1_port *up;
> +	int ret = 0;
> +
> +	if (pdev->dev.of_node) {
> +		ret = of_alias_get_id(pdev->dev.of_node, "serial");
> +		if (ret < 0) {
> +			dev_err(&pdev->dev, "failed to get alias/pdev id, errno %d\n", ret);
> +			return ret;
> +		}
> +	}
> +	up = &ma35d1serial_ports[ret];
> +	up->port.line = ret;
> +	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res_mem)
> +		return -ENODEV;
> +
> +	up->port.iobase = res_mem->start;
> +	up->port.membase = ioremap(up->port.iobase, MA35_UART_REG_SIZE);

Check this too.

> +	up->port.ops = &ma35d1serial_ops;
> +
> +	spin_lock_init(&up->port.lock);
> +
> +	up->clk = of_clk_get(pdev->dev.of_node, 0);
> +	if (IS_ERR(up->clk)) {
> +		ret = PTR_ERR(up->clk);
> +		dev_err(&pdev->dev, "failed to get core clk: %d\n", ret);
> +		goto err_iounmap;
> +	}
> +
> +	ret = clk_prepare_enable(up->clk);
> +	if (ret)
> +		goto err_iounmap;
> +
> +	if (up->port.line != 0)
> +		up->port.uartclk = clk_get_rate(up->clk);
> +
> +	ret = platform_get_irq(pdev, 0);
> +	if (ret < 0)
> +		goto err_clk_disable;
> +
> +	up->port.irq = ret;
> +	up->port.dev = &pdev->dev;
> +	up->port.flags = UPF_BOOT_AUTOCONF;
> +
> +	platform_set_drvdata(pdev, up);
> +
> +	ret = uart_add_one_port(&ma35d1serial_reg, &up->port);
> +	if (ret < 0)
> +		goto err_free_irq;
> +
> +	return 0;
> +
> +err_free_irq:
> +	free_irq(up->port.irq, &up->port);
> +
> +err_clk_disable:
> +	clk_disable_unprepare(up->clk);
> +
> +err_iounmap:
> +	iounmap(up->port.membase);
> +	return ret;
> +}

thanks,
Jacky Huang May 24, 2023, 8:34 a.m. UTC | #2
Dear Jiri,

Thanks for your advice.

On 2023/5/24 下午 03:42, Jiri Slaby wrote:
> On 16. 05. 23, 9:52, Jacky Huang wrote:
>> +static void ma35d1serial_config_port(struct uart_port *port, int flags)
>> +{
>> +    /*
>> +     * Driver core for serial ports forces a non-zero value for port 
>> type.
>> +     * Write an arbitrary value here to accommodate the serial core 
>> driver,
>> +     * as ID part of UAPI is redundant.
>> +     */
>> +    port->type = 1;
>
> So this 1 translates to PORT_8250. Why not to use it directly? Or 
> something more saner like PORT_16550A?
>
It's not actually 8250 or 16550A.
Can we add the following definition to 
'include/uapi/linux/serial_core.h' and use PORT_MA35 instead?

#define PORT_MA35    124


>> +}
>> +
>> +static int ma35d1serial_verify_port(struct uart_port *port, struct 
>> serial_struct *ser)
>> +{
>> +    if (port->type != PORT_UNKNOWN && ser->type != 1)
>> +        return -EINVAL;
>> +
>> +    return 0;
>> +}
> ...
>> +static int __init ma35d1serial_console_setup(struct console *co, 
>> char *options)
>> +{
>> +    struct device_node *np = ma35d1serial_uart_nodes[co->index];
>> +    struct uart_ma35d1_port *p = &ma35d1serial_ports[co->index];
>> +    u32 val32[4];
>> +    struct uart_port *port;
>> +    int baud = 115200;
>> +    int bits = 8;
>> +    int parity = 'n';
>> +    int flow = 'n';
>> +
>> +    /*
>> +     * Check whether an invalid uart number has been specified, and
>
> You dereferenced ma35d1serial_uart_nodes already. Doesn't 
> console=ttyNVT1000 (or something like that) crash the system?
>

I will add the following check before np = 
"ma35d1serial_uart_nodes[co->index]".

if (co->index < 0 || co->index >= MA35_UART_NR)
     return -EINVAL;


>> +     * if so, search for the first available port that does have
>> +     * console support.
>
> The code below doesn't match this comment.

Yes, I will remove the above comment.

>
>> +     */
>> +    if ((co->index < 0) || (co->index >= MA35_UART_NR)) {
>> +        pr_debug("Console Port%x out of range\n", co->index);
>> +        return -EINVAL;
>> +    }
>> +
>> +    if (of_property_read_u32_array(np, "reg", val32, 4) != 0)
>
> Shouldn't that 4 be ARRAY_SIZE(val32) instead?
>

Will be fixed.

>> +        return -EINVAL;
>
> One \n here please.
>

Okay, I will add it.

>> +    p->port.iobase = val32[1];
>> +    p->port.membase = ioremap(p->port.iobase, MA35_UART_REG_SIZE);
>
> What if this fails?
>

I will add a check for the return value.

>> +    p->port.ops = &ma35d1serial_ops;
>> +    p->port.line = 0;
>> +    p->port.uartclk = MA35_UART_CONSOLE_CLK;
>> +
>> +    port = &ma35d1serial_ports[co->index].port;
>
> Isn't this:
>   port = &p->port;
> ?
>
> Either use port on all above lines or drop the "port" variable 
> completely and use "p->port" below instead.
>

I will remove port variable and use p->port only.

>> +
>> +    if (options)
>> +        uart_parse_options(options, &baud, &parity, &bits, &flow);
>> +
>> +    return uart_set_options(port, co, baud, parity, bits, flow);
>> +}
>> +
>> +static struct console ma35d1serial_console = {
>> +    .name    = "ttyNVT",
>> +    .write   = ma35d1serial_console_write,
>> +    .device  = uart_console_device,
>> +    .setup   = ma35d1serial_console_setup,
>> +    .flags   = CON_PRINTBUFFER | CON_ENABLED,
>> +    .index   = -1,
>> +    .data    = &ma35d1serial_reg,
>
> I don't see console->data used anywhere in the driver?
>

I will remove it.

>> +};
> ...
>> +static int ma35d1serial_probe(struct platform_device *pdev)
>> +{
>> +    struct resource *res_mem;
>> +    struct uart_ma35d1_port *up;
>> +    int ret = 0;
>> +
>> +    if (pdev->dev.of_node) {
>> +        ret = of_alias_get_id(pdev->dev.of_node, "serial");
>> +        if (ret < 0) {
>> +            dev_err(&pdev->dev, "failed to get alias/pdev id, errno 
>> %d\n", ret);
>> +            return ret;
>> +        }
>> +    }
>> +    up = &ma35d1serial_ports[ret];
>> +    up->port.line = ret;
>> +    res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +    if (!res_mem)
>> +        return -ENODEV;
>> +
>> +    up->port.iobase = res_mem->start;
>> +    up->port.membase = ioremap(up->port.iobase, MA35_UART_REG_SIZE);
>
> Check this too.
>

Okay, sure.

>> +    up->port.ops = &ma35d1serial_ops;
>> +
>> +    spin_lock_init(&up->port.lock);
>> +
>> +    up->clk = of_clk_get(pdev->dev.of_node, 0);
>> +    if (IS_ERR(up->clk)) {
>> +        ret = PTR_ERR(up->clk);
>> +        dev_err(&pdev->dev, "failed to get core clk: %d\n", ret);
>> +        goto err_iounmap;
>> +    }
>> +
>> +    ret = clk_prepare_enable(up->clk);
>> +    if (ret)
>> +        goto err_iounmap;
>> +
>> +    if (up->port.line != 0)
>> +        up->port.uartclk = clk_get_rate(up->clk);
>> +
>> +    ret = platform_get_irq(pdev, 0);
>> +    if (ret < 0)
>> +        goto err_clk_disable;
>> +
>> +    up->port.irq = ret;
>> +    up->port.dev = &pdev->dev;
>> +    up->port.flags = UPF_BOOT_AUTOCONF;
>> +
>> +    platform_set_drvdata(pdev, up);
>> +
>> +    ret = uart_add_one_port(&ma35d1serial_reg, &up->port);
>> +    if (ret < 0)
>> +        goto err_free_irq;
>> +
>> +    return 0;
>> +
>> +err_free_irq:
>> +    free_irq(up->port.irq, &up->port);
>> +
>> +err_clk_disable:
>> +    clk_disable_unprepare(up->clk);
>> +
>> +err_iounmap:
>> +    iounmap(up->port.membase);
>> +    return ret;
>> +}
>
> thanks,

Best regards,
Jacky Huang
Arnd Bergmann May 24, 2023, 9 a.m. UTC | #3
On Wed, May 24, 2023, at 10:34, Jacky Huang wrote:
> On 2023/5/24 下午 03:42, Jiri Slaby wrote:
>> On 16. 05. 23, 9:52, Jacky Huang wrote:
>>> +static void ma35d1serial_config_port(struct uart_port *port, int flags)
>>> +{
>>> +    /*
>>> +     * Driver core for serial ports forces a non-zero value for port 
>>> type.
>>> +     * Write an arbitrary value here to accommodate the serial core 
>>> driver,
>>> +     * as ID part of UAPI is redundant.
>>> +     */
>>> +    port->type = 1;
>>
>> So this 1 translates to PORT_8250. Why not to use it directly? Or 
>> something more saner like PORT_16550A?
>>
> It's not actually 8250 or 16550A.
> Can we add the following definition to 
> 'include/uapi/linux/serial_core.h' and use PORT_MA35 instead?
>
> #define PORT_MA35    124

This was already in a previous version, until Greg commented
that it was probably not needed:

https://lore.kernel.org/lkml/20fc81c9-5517-ce1e-639a-3b425cf27759@gmail.com/

Since leaving port->type at PORT_UNKNOWN doesn't work, and almost
all other drivers have something in serial_core.h, it's probably
best to do the same here. Checking the other drivers showed that
drivers/tty/serial/lantiq.c is currently the only exception, it
defines PORT_LTQ_ASC locally, which causes a conflict with
PORT_SPRD.

    Arnd
Jiri Slaby May 25, 2023, 5:48 a.m. UTC | #4
On 24. 05. 23, 11:00, Arnd Bergmann wrote:
> On Wed, May 24, 2023, at 10:34, Jacky Huang wrote:
>> On 2023/5/24 下午 03:42, Jiri Slaby wrote:
>>> On 16. 05. 23, 9:52, Jacky Huang wrote:
>>>> +static void ma35d1serial_config_port(struct uart_port *port, int flags)
>>>> +{
>>>> +    /*
>>>> +     * Driver core for serial ports forces a non-zero value for port
>>>> type.
>>>> +     * Write an arbitrary value here to accommodate the serial core
>>>> driver,
>>>> +     * as ID part of UAPI is redundant.
>>>> +     */
>>>> +    port->type = 1;
>>>
>>> So this 1 translates to PORT_8250. Why not to use it directly? Or
>>> something more saner like PORT_16550A?
>>>
>> It's not actually 8250 or 16550A.
>> Can we add the following definition to
>> 'include/uapi/linux/serial_core.h' and use PORT_MA35 instead?
>>
>> #define PORT_MA35    124
> 
> This was already in a previous version, until Greg commented
> that it was probably not needed:
> 
> https://lore.kernel.org/lkml/20fc81c9-5517-ce1e-639a-3b425cf27759@gmail.com/
> 
> Since leaving port->type at PORT_UNKNOWN doesn't work, and almost
> all other drivers have something in serial_core.h, it's probably
> best to do the same here. Checking the other drivers showed that
> drivers/tty/serial/lantiq.c is currently the only exception, it
> defines PORT_LTQ_ASC locally, which causes a conflict with
> PORT_SPRD.

Hmm.

Anyone has an idea what this is really used for in userspace? Can we 
replace all of them by simply some sort of "PORT_OTHER"?

For example:

xdg-open `echo -n 'https://codesearch.debian.net/search?q=\b('; sed -n 
's@#define\s\(\w\+\)\s.*@\1@ p' include/uapi/linux/serial_core.h | tail 
-20 | sed 's@.* \(.*\)[\x09 ][\x09 ]*.*@\1@'|paste -sd'|' | tr -d '\n'; 
echo ')\b'`

gives _no_ clue. FTR the above translates here into:
https://codesearch.debian.net/search?q=\b(PORT_HSCIF|PORT_ASC|PORT_TILEGX|PORT_MEN_Z135|PORT_SC16IS7XX|PORT_MESON|PORT_DIGICOLOR|PORT_SPRD|PORT_CRIS|PORT_STM32|PORT_MVEBU|PORT_PIC32|PORT_MPS2UART|PORT_MTK_BTIF|PORT_RDA|PORT_MLB_USIO|PORT_SIFIVE_V0|PORT_SUNIX|PORT_LINFLEXUART|PORT_SUNPLUS)\b

thanks,
Jacky Huang May 30, 2023, 1:09 a.m. UTC | #5
Dear Jiri,


On 2023/5/24 下午 04:34, Jacky Huang wrote:
> Dear Jiri,
>
> Thanks for your advice.
>
> On 2023/5/24 下午 03:42, Jiri Slaby wrote:
>> On 16. 05. 23, 9:52, Jacky Huang wrote:
>>> +static void ma35d1serial_config_port(struct uart_port *port, int 
>>> flags)
>>> +{
>>> +    /*
>>> +     * Driver core for serial ports forces a non-zero value for 
>>> port type.
>>> +     * Write an arbitrary value here to accommodate the serial core 
>>> driver,
>>> +     * as ID part of UAPI is redundant.
>>> +     */
>>> +    port->type = 1;
>>
>> So this 1 translates to PORT_8250. Why not to use it directly? Or 
>> something more saner like PORT_16550A?
>>
> It's not actually 8250 or 16550A.
> Can we add the following definition to 
> 'include/uapi/linux/serial_core.h' and use PORT_MA35 instead?
>
> #define PORT_MA35    124
>
>
>>> +}
>>> +
>>> +static int ma35d1serial_verify_port(struct uart_port *port, struct 
>>> serial_struct *ser)
>>> +{
>>> +    if (port->type != PORT_UNKNOWN && ser->type != 1)
>>> +        return -EINVAL;
>>> +
>>> +    return 0;
>>> +}
>> ...
>>> +static int __init ma35d1serial_console_setup(struct console *co, 
>>> char *options)
>>> +{
>>> +    struct device_node *np = ma35d1serial_uart_nodes[co->index];
>>> +    struct uart_ma35d1_port *p = &ma35d1serial_ports[co->index];
>>> +    u32 val32[4];
>>> +    struct uart_port *port;
>>> +    int baud = 115200;
>>> +    int bits = 8;
>>> +    int parity = 'n';
>>> +    int flow = 'n';
>>> +
>>> +    /*
>>> +     * Check whether an invalid uart number has been specified, and
>>
>> You dereferenced ma35d1serial_uart_nodes already. Doesn't 
>> console=ttyNVT1000 (or something like that) crash the system?
>>
>
> I will add the following check before np = 
> "ma35d1serial_uart_nodes[co->index]".
>
> if (co->index < 0 || co->index >= MA35_UART_NR)
>     return -EINVAL;
>
>
>>> +     * if so, search for the first available port that does have
>>> +     * console support.
>>
>> The code below doesn't match this comment.
>
> Yes, I will remove the above comment.
>
>>
>>> +     */
>>> +    if ((co->index < 0) || (co->index >= MA35_UART_NR)) {
>>> +        pr_debug("Console Port%x out of range\n", co->index);
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    if (of_property_read_u32_array(np, "reg", val32, 4) != 0)
>>
>> Shouldn't that 4 be ARRAY_SIZE(val32) instead?
>>
>
> Will be fixed.
>
>>> +        return -EINVAL;
>>
>> One \n here please.
>>
>
> Okay, I will add it.
>
>>> +    p->port.iobase = val32[1];
>>> +    p->port.membase = ioremap(p->port.iobase, MA35_UART_REG_SIZE);
>>
>> What if this fails?
>>
>
> I will add a check for the return value.
>
>>> +    p->port.ops = &ma35d1serial_ops;
>>> +    p->port.line = 0;
>>> +    p->port.uartclk = MA35_UART_CONSOLE_CLK;
>>> +
>>> +    port = &ma35d1serial_ports[co->index].port;
>>
>> Isn't this:
>>   port = &p->port;
>> ?
>>
>> Either use port on all above lines or drop the "port" variable 
>> completely and use "p->port" below instead.
>>
>
> I will remove port variable and use p->port only.
>
>>> +
>>> +    if (options)
>>> +        uart_parse_options(options, &baud, &parity, &bits, &flow);
>>> +
>>> +    return uart_set_options(port, co, baud, parity, bits, flow);
>>> +}
>>> +
>>> +static struct console ma35d1serial_console = {
>>> +    .name    = "ttyNVT",
>>> +    .write   = ma35d1serial_console_write,
>>> +    .device  = uart_console_device,
>>> +    .setup   = ma35d1serial_console_setup,
>>> +    .flags   = CON_PRINTBUFFER | CON_ENABLED,
>>> +    .index   = -1,
>>> +    .data    = &ma35d1serial_reg,
>>
>> I don't see console->data used anywhere in the driver?
>>
>
> I will remove it.
>

I removed the " .data    = &ma35d1serial_reg", but kernel crashed in 
'drivers/tty/serial/serial_core.c'.

The variable 'p' of  uart_console_device() refer to a NULL, because 
co->data is NULL.
As a result, kernel crashed at 'p->tty_driver'.

struct tty_driver *uart_console_device(struct console *co, int *index)
{
     struct uart_driver *p = co->data;
     *index = co->index;
     return p->tty_driver;
}

We seem to be unable to remove it.
If there are no other considerations, I will keep it in the next version.

>>> +};
>> ...
>>> +static int ma35d1serial_probe(struct platform_device *pdev)
>>> +{
>>> +    struct resource *res_mem;
>>> +    struct uart_ma35d1_port *up;
>>> +    int ret = 0;
>>> +
>>> +    if (pdev->dev.of_node) {
>>> +        ret = of_alias_get_id(pdev->dev.of_node, "serial");
>>> +        if (ret < 0) {
>>> +            dev_err(&pdev->dev, "failed to get alias/pdev id, errno 
>>> %d\n", ret);
>>> +            return ret;
>>> +        }
>>> +    }
>>> +    up = &ma35d1serial_ports[ret];
>>> +    up->port.line = ret;
>>> +    res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> +    if (!res_mem)
>>> +        return -ENODEV;
>>> +
>>> +    up->port.iobase = res_mem->start;
>>> +    up->port.membase = ioremap(up->port.iobase, MA35_UART_REG_SIZE);
>>
>> Check this too.
>>
>
> Okay, sure.
>
>>> +    up->port.ops = &ma35d1serial_ops;
>>> +
>>> +    spin_lock_init(&up->port.lock);
>>> +
>>> +    up->clk = of_clk_get(pdev->dev.of_node, 0);
>>> +    if (IS_ERR(up->clk)) {
>>> +        ret = PTR_ERR(up->clk);
>>> +        dev_err(&pdev->dev, "failed to get core clk: %d\n", ret);
>>> +        goto err_iounmap;
>>> +    }
>>> +
>>> +    ret = clk_prepare_enable(up->clk);
>>> +    if (ret)
>>> +        goto err_iounmap;
>>> +
>>> +    if (up->port.line != 0)
>>> +        up->port.uartclk = clk_get_rate(up->clk);
>>> +
>>> +    ret = platform_get_irq(pdev, 0);
>>> +    if (ret < 0)
>>> +        goto err_clk_disable;
>>> +
>>> +    up->port.irq = ret;
>>> +    up->port.dev = &pdev->dev;
>>> +    up->port.flags = UPF_BOOT_AUTOCONF;
>>> +
>>> +    platform_set_drvdata(pdev, up);
>>> +
>>> +    ret = uart_add_one_port(&ma35d1serial_reg, &up->port);
>>> +    if (ret < 0)
>>> +        goto err_free_irq;
>>> +
>>> +    return 0;
>>> +
>>> +err_free_irq:
>>> +    free_irq(up->port.irq, &up->port);
>>> +
>>> +err_clk_disable:
>>> +    clk_disable_unprepare(up->clk);
>>> +
>>> +err_iounmap:
>>> +    iounmap(up->port.membase);
>>> +    return ret;
>>> +}
>>
>> thanks,
>
> Best regards,
> Jacky Huang
>

Best regards,
Jacky Huang
Jiri Slaby May 30, 2023, 5:35 a.m. UTC | #6
Hi,

On 30. 05. 23, 3:09, Jacky Huang wrote:
>>>> +
>>>> +    if (options)
>>>> +        uart_parse_options(options, &baud, &parity, &bits, &flow);
>>>> +
>>>> +    return uart_set_options(port, co, baud, parity, bits, flow);
>>>> +}
>>>> +
>>>> +static struct console ma35d1serial_console = {
>>>> +    .name    = "ttyNVT",
>>>> +    .write   = ma35d1serial_console_write,
>>>> +    .device  = uart_console_device,
>>>> +    .setup   = ma35d1serial_console_setup,
>>>> +    .flags   = CON_PRINTBUFFER | CON_ENABLED,
>>>> +    .index   = -1,
>>>> +    .data    = &ma35d1serial_reg,
>>>
>>> I don't see console->data used anywhere in the driver?
>>>
>>
>> I will remove it.
>>
> 
> I removed the " .data    = &ma35d1serial_reg", but kernel crashed in 
> 'drivers/tty/serial/serial_core.c'.
> 
> The variable 'p' of  uart_console_device() refer to a NULL, because 
> co->data is NULL.
> As a result, kernel crashed at 'p->tty_driver'.
> 
> struct tty_driver *uart_console_device(struct console *co, int *index)
> {
>      struct uart_driver *p = co->data;
>      *index = co->index;
>      return p->tty_driver;
> }
> 
> We seem to be unable to remove it.
> If there are no other considerations, I will keep it in the next version.

Ah, yeah. Sorry, my bad.
diff mbox series

Patch

diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 398e5aac2e77..85ac6fc1ff1d 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1555,6 +1555,24 @@  config SERIAL_SUNPLUS_CONSOLE
 	  you can alter that using a kernel command line option such as
 	  "console=ttySUPx".
 
+config SERIAL_NUVOTON_MA35D1
+	tristate "Nuvoton MA35D1 family UART support"
+	depends on ARCH_MA35 || COMPILE_TEST
+	select SERIAL_CORE
+	help
+	  This driver supports Nuvoton MA35D1 family UART ports. If you would
+	  like to use them, you must answer Y or M to this option. Note that
+	  for use as console, it must be included in kernel and not as a
+	  module
+
+config SERIAL_NUVOTON_MA35D1_CONSOLE
+	bool "Console on a Nuvotn MA35D1 family UART port"
+	depends on SERIAL_NUVOTON_MA35D1=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  Select this options if you'd like to use the UART port0 of the
+	  Nuvoton MA35D1 family as a console.
+
 endmenu
 
 config SERIAL_MCTRL_GPIO
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index cd9afd9e3018..0e823851c42c 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -93,3 +93,4 @@  obj-$(CONFIG_SERIAL_MCTRL_GPIO)	+= serial_mctrl_gpio.o
 
 obj-$(CONFIG_SERIAL_KGDB_NMI) += kgdb_nmi.o
 obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
+obj-$(CONFIG_SERIAL_NUVOTON_MA35D1) += ma35d1_serial.o
diff --git a/drivers/tty/serial/ma35d1_serial.c b/drivers/tty/serial/ma35d1_serial.c
new file mode 100644
index 000000000000..941332093db3
--- /dev/null
+++ b/drivers/tty/serial/ma35d1_serial.c
@@ -0,0 +1,800 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  MA35D1 serial driver
+ *  Copyright (C) 2023 Nuvoton Technology Corp.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/tty_flip.h>
+#include <linux/units.h>
+
+#define MA35_UART_NR		17
+
+#define MA35_RBR_REG		0x00
+#define MA35_THR_REG		0x00
+#define MA35_IER_REG		0x04
+#define MA35_FCR_REG		0x08
+#define MA35_LCR_REG		0x0C
+#define MA35_MCR_REG		0x10
+#define MA35_MSR_REG		0x14
+#define MA35_FSR_REG		0x18
+#define MA35_ISR_REG		0x1C
+#define MA35_TOR_REG		0x20
+#define MA35_BAUD_REG		0x24
+#define MA35_ALTCTL_REG		0x2C
+#define MA35_FUN_SEL_REG	0x30
+#define MA35_WKCTL_REG		0x40
+#define MA35_WKSTS_REG		0x44
+
+/* MA35_IER_REG - Interrupt Enable Register */
+#define MA35_IER_RDA_IEN	BIT(0)  /* RBR Available Interrupt Enable */
+#define MA35_IER_THRE_IEN	BIT(1)  /* THR Empty Interrupt Enable */
+#define MA35_IER_RLS_IEN	BIT(2)  /* RX Line Status Interrupt Enable */
+#define MA35_IER_RTO_IEN	BIT(4)  /* RX Time-out Interrupt Enable */
+#define MA35_IER_BUFERR_IEN	BIT(5)  /* Buffer Error Interrupt Enable */
+#define MA35_IER_TIME_OUT_EN	BIT(11) /* RX Buffer Time-out Counter Enable */
+#define MA35_IER_AUTO_RTS	BIT(12) /* nRTS Auto-flow Control Enable */
+#define MA35_IER_AUTO_CTS	BIT(13) /* nCTS Auto-flow Control Enable */
+
+/* MA35_FCR_REG - FIFO Control Register */
+#define MA35_FCR_RFR		BIT(1)  /* RX Field Software Reset */
+#define MA35_FCR_TFR		BIT(2)  /* TX Field Software Reset */
+#define MA35_FCR_RFITL_MASK	GENMASK(7, 4) /* RX FIFO Interrupt Trigger Level */
+#define MA35_FCR_RFITL_1BYTE	FIELD_PREP(MA35_FCR_RFITL_MASK, 0)
+#define MA35_FCR_RFITL_4BYTES	FIELD_PREP(MA35_FCR_RFITL_MASK, 1)
+#define MA35_FCR_RFITL_8BYTES	FIELD_PREP(MA35_FCR_RFITL_MASK, 2)
+#define MA35_FCR_RFITL_14BYTES	FIELD_PREP(MA35_FCR_RFITL_MASK, 3)
+#define MA35_FCR_RFITL_30BYTES	FIELD_PREP(MA35_FCR_RFITL_MASK, 4)
+#define MA35_FCR_RTSTL_MASK	GENMASK(19, 16) /* nRTS Trigger Level */
+#define MA35_FCR_RTSTL_1BYTE	FIELD_PREP(MA35_FCR_RTSTL_MASK, 0)
+#define MA35_FCR_RTSTL_4BYTES	FIELD_PREP(MA35_FCR_RTSTL_MASK, 1)
+#define MA35_FCR_RTSTL_8BYTES	FIELD_PREP(MA35_FCR_RTSTL_MASK, 2)
+#define MA35_FCR_RTSTL_14BYTES	FIELD_PREP(MA35_FCR_RTSTL_MASK, 3)
+#define MA35_FCR_RTSTLL_30BYTES	FIELD_PREP(MA35_FCR_RTSTL_MASK, 4)
+
+/* MA35_LCR_REG - Line Control Register */
+#define	MA35_LCR_NSB		BIT(2)  /* Number of “STOP Bit” */
+#define MA35_LCR_PBE		BIT(3)  /* Parity Bit Enable */
+#define MA35_LCR_EPE		BIT(4)  /* Even Parity Enable */
+#define MA35_LCR_SPE		BIT(5)  /* Stick Parity Enable */
+#define MA35_LCR_BREAK		BIT(6)  /* Break Control */
+#define MA35_LCR_WLS_MASK	GENMASK(1, 0) /* Word Length Selection */
+#define MA35_LCR_WLS_5BITS	FIELD_PREP(MA35_LCR_WLS_MASK, 0)
+#define MA35_LCR_WLS_6BITS	FIELD_PREP(MA35_LCR_WLS_MASK, 1)
+#define MA35_LCR_WLS_7BITS	FIELD_PREP(MA35_LCR_WLS_MASK, 2)
+#define MA35_LCR_WLS_8BITS	FIELD_PREP(MA35_LCR_WLS_MASK, 3)
+
+/* MA35_MCR_REG - Modem Control Register */
+#define MA35_MCR_RTS_CTRL	BIT(1)  /* nRTS Signal Control */
+#define MA35_MCR_RTSACTLV	BIT(9)  /* nRTS Pin Active Level */
+#define MA35_MCR_RTSSTS		BIT(13) /* nRTS Pin Status (Read Only) */
+
+/* MA35_MSR_REG - Modem Status Register */
+#define MA35_MSR_CTSDETF	BIT(0)  /* Detect nCTS State Change Flag */
+#define MA35_MSR_CTSSTS		BIT(4)  /* nCTS Pin Status (Read Only) */
+#define MA35_MSR_CTSACTLV	BIT(8)  /* nCTS Pin Active Level */
+
+/* MA35_FSR_REG - FIFO Status Register */
+#define MA35_FSR_RX_OVER_IF	BIT(0)  /* RX Overflow Error Interrupt Flag */
+#define MA35_FSR_PEF		BIT(4)  /* Parity Error Flag*/
+#define MA35_FSR_FEF		BIT(5)  /* Framing Error Flag */
+#define MA35_FSR_BIF		BIT(6)  /* Break Interrupt Flag */
+#define MA35_FSR_RX_EMPTY	BIT(14) /* Receiver FIFO Empty (Read Only) */
+#define MA35_FSR_RX_FULL	BIT(15) /* Receiver FIFO Full (Read Only) */
+#define MA35_FSR_TX_EMPTY	BIT(22) /* Transmitter FIFO Empty (Read Only) */
+#define MA35_FSR_TX_FULL	BIT(23) /* Transmitter FIFO Full (Read Only) */
+#define MA35_FSR_TX_OVER_IF	BIT(24) /* TX Overflow Error Interrupt Flag */
+#define MA35_FSR_TE_FLAG	BIT(28) /* Transmitter Empty Flag (Read Only) */
+#define MA35_FSR_RXPTR_MSK	GENMASK(13, 8) /* TX FIFO Pointer mask */
+#define MA35_FSR_TXPTR_MSK	GENMASK(21, 16) /* RX FIFO Pointer mask */
+
+/* MA35_ISR_REG - Interrupt Status Register */
+#define MA35_ISR_RDA_IF		BIT(0)  /* RBR Available Interrupt Flag */
+#define MA35_ISR_THRE_IF	BIT(1)  /* THR Empty Interrupt Flag */
+#define MA35_ISR_RLSIF		BIT(2)  /* Receive Line Interrupt Flag */
+#define MA35_ISR_MODEMIF	BIT(3)  /* MODEM Interrupt Flag */
+#define MA35_ISR_RXTO_IF	BIT(4)  /* RX Time-out Interrupt Flag */
+#define MA35_ISR_BUFEIF		BIT(5)  /* Buffer Error Interrupt Flag */
+#define MA35_ISR_WK_IF		BIT(6)  /* UART Wake-up Interrupt Flag */
+#define MA35_ISR_RDAINT		BIT(8)  /* RBR Available Interrupt Indicator */
+#define MA35_ISR_THRE_INT	BIT(9)  /* THR Empty Interrupt Indicator */
+#define MA35_ISR_ALL		0xFFFFFFFF
+
+/* MA35_BAUD_REG - Baud Rate Divider Register */
+#define	MA35_BAUD_MODE_MASK	GENMASK(29, 28)
+#define MA35_BAUD_MODE0		FIELD_PREP(MA35_BAUD_MODE_MASK, 0)
+#define MA35_BAUD_MODE1		FIELD_PREP(MA35_BAUD_MODE_MASK, 2)
+#define MA35_BAUD_MODE2		FIELD_PREP(MA35_BAUD_MODE_MASK, 3)
+#define	MA35_BAUD_MASK		GENMASK(15, 0)
+
+/* MA35_ALTCTL_REG - Alternate Control/Status Register */
+#define MA35_ALTCTL_RS485AUD	BIT(10) /* RS-485 Auto Direction Function */
+
+/* MA35_FUN_SEL_REG - Function Select Register */
+#define MA35_FUN_SEL_MASK	GENMASK(2, 0)
+#define MA35_FUN_SEL_UART	FIELD_PREP(MA35_FUN_SEL_MASK, 0)
+#define MA35_FUN_SEL_RS485	FIELD_PREP(MA35_FUN_SEL_MASK, 3)
+
+/* The constrain for MA35D1 UART baud rate divider */
+#define MA35_BAUD_DIV_MAX	0xFFFF
+#define MA35_BAUD_DIV_MIN	11
+
+/* UART FIFO depth */
+#define MA35_UART_FIFO_DEPTH	32
+/* UART console clock */
+#define MA35_UART_CONSOLE_CLK	(24 * HZ_PER_MHZ)
+/* UART register ioremap size */
+#define MA35_UART_REG_SIZE	0x100
+/* Rx Timeout */
+#define MA35_UART_RX_TOUT	0x40
+
+#define MA35_ISR_IF_CHECK	(MA35_ISR_RDA_IF | MA35_ISR_RXTO_IF | \
+				 MA35_ISR_THRE_INT | MA35_ISR_BUFEIF)
+
+static struct uart_driver ma35d1serial_reg;
+
+struct uart_ma35d1_port {
+	struct uart_port port;
+	struct clk *clk;
+	u16 capabilities; /* port capabilities */
+	u8 ier;
+	u8 lcr;
+	u8 mcr;
+	u32 baud_rate;
+	u32 console_baud_rate;
+	u32 console_line;
+	u32 console_int;
+};
+
+static struct uart_ma35d1_port ma35d1serial_ports[MA35_UART_NR];
+
+static struct uart_ma35d1_port *to_ma35d1_uart_port(struct uart_port *uart)
+{
+	return container_of(uart, struct uart_ma35d1_port, port);
+}
+
+static u32 serial_in(struct uart_ma35d1_port *p, u32 offset)
+{
+	return readl_relaxed(p->port.membase + offset);
+}
+
+static void serial_out(struct uart_ma35d1_port *p, u32 offset, u32 value)
+{
+	writel_relaxed(value, p->port.membase + offset);
+}
+
+static void __stop_tx(struct uart_ma35d1_port *p)
+{
+	u32 ier;
+
+	ier = serial_in(p, MA35_IER_REG);
+	if (ier & MA35_IER_THRE_IEN)
+		serial_out(p, MA35_IER_REG, ier & ~MA35_IER_THRE_IEN);
+}
+
+static void ma35d1serial_stop_tx(struct uart_port *port)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+	__stop_tx(up);
+}
+
+static void transmit_chars(struct uart_ma35d1_port *up)
+{
+	u32 count;
+	u8 ch;
+
+	if (uart_tx_stopped(&up->port)) {
+		ma35d1serial_stop_tx(&up->port);
+		return;
+	}
+	count = MA35_UART_FIFO_DEPTH - FIELD_GET(MA35_FSR_TXPTR_MSK,
+						 serial_in(up, MA35_FSR_REG));
+	uart_port_tx_limited(&up->port, ch, count,
+			     !(serial_in(up, MA35_FSR_REG) & MA35_FSR_TX_FULL),
+			     serial_out(up, MA35_THR_REG, ch),
+			     ({}));
+}
+
+static void ma35d1serial_start_tx(struct uart_port *port)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	u32 ier;
+
+	ier = serial_in(up, MA35_IER_REG);
+	serial_out(up, MA35_IER_REG, ier & ~MA35_IER_THRE_IEN);
+	transmit_chars(up);
+	serial_out(up, MA35_IER_REG, ier | MA35_IER_THRE_IEN);
+}
+
+static void ma35d1serial_stop_rx(struct uart_port *port)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+	serial_out(up, MA35_IER_REG, serial_in(up, MA35_IER_REG) & ~MA35_IER_RDA_IEN);
+}
+
+static void receive_chars(struct uart_ma35d1_port *up)
+{
+	u8 ch, flag;
+	u32 fsr;
+	int max_count = 256;
+
+	fsr = serial_in(up, MA35_FSR_REG);
+	do {
+		flag = TTY_NORMAL;
+		up->port.icount.rx++;
+
+		if (unlikely(fsr & (MA35_FSR_BIF | MA35_FSR_FEF |
+				    MA35_FSR_PEF | MA35_FSR_RX_OVER_IF))) {
+			if (fsr & MA35_FSR_BIF) {
+				up->port.icount.brk++;
+				if (uart_handle_break(&up->port))
+					continue;
+			}
+			if (fsr & MA35_FSR_FEF)
+				up->port.icount.frame++;
+			if (fsr & MA35_FSR_PEF)
+				up->port.icount.parity++;
+			if (fsr & MA35_FSR_RX_OVER_IF)
+				up->port.icount.overrun++;
+
+			serial_out(up, MA35_FSR_REG,
+				   fsr & (MA35_FSR_BIF | MA35_FSR_FEF |
+					  MA35_FSR_PEF | MA35_FSR_RX_OVER_IF));
+			if (fsr & MA35_FSR_BIF)
+				flag = TTY_BREAK;
+			else if (fsr & MA35_FSR_PEF)
+				flag = TTY_PARITY;
+			else if (fsr & MA35_FSR_FEF)
+				flag = TTY_FRAME;
+		}
+
+		ch = serial_in(up, MA35_RBR_REG);
+		if (uart_handle_sysrq_char(&up->port, ch))
+			continue;
+
+		spin_lock(&up->port.lock);
+		uart_insert_char(&up->port, fsr, MA35_FSR_RX_OVER_IF, ch, flag);
+		spin_unlock(&up->port.lock);
+
+		fsr = serial_in(up, MA35_FSR_REG);
+	} while (!(fsr & MA35_FSR_RX_EMPTY) && (max_count-- > 0));
+
+	spin_lock(&up->port.lock);
+	tty_flip_buffer_push(&up->port.state->port);
+	spin_unlock(&up->port.lock);
+}
+
+static irqreturn_t ma35d1serial_interrupt(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	u32 isr, fsr;
+
+	isr = serial_in(up, MA35_ISR_REG);
+	fsr = serial_in(up, MA35_FSR_REG);
+
+	if (!(isr & MA35_ISR_IF_CHECK))
+		return IRQ_NONE;
+
+	if (isr & (MA35_ISR_RDA_IF | MA35_ISR_RXTO_IF))
+		receive_chars(up);
+	if (isr & MA35_ISR_THRE_INT)
+		transmit_chars(up);
+	if (fsr & MA35_FSR_TX_OVER_IF)
+		serial_out(up, MA35_FSR_REG, MA35_FSR_TX_OVER_IF);
+
+	return IRQ_HANDLED;
+}
+
+static u32 ma35d1serial_tx_empty(struct uart_port *port)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	u32 fsr;
+
+	fsr = serial_in(up, MA35_FSR_REG);
+	return (fsr & (MA35_FSR_TE_FLAG | MA35_FSR_TX_EMPTY)) ==
+		(MA35_FSR_TE_FLAG | MA35_FSR_TX_EMPTY) ? TIOCSER_TEMT : 0;
+}
+
+static u32 ma35d1serial_get_mctrl(struct uart_port *port)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	u32 status;
+	u32 ret = 0;
+
+	status = serial_in(up, MA35_MSR_REG);
+	if (!(status & MA35_MSR_CTSSTS))
+		ret |= TIOCM_CTS;
+	return ret;
+}
+
+static void ma35d1serial_set_mctrl(struct uart_port *port, u32 mctrl)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	u32 mcr;
+	u32 ier;
+
+	mcr = serial_in(up, MA35_MCR_REG);
+	mcr &= ~MA35_MCR_RTS_CTRL;
+
+	if (mctrl & TIOCM_RTS)
+		mcr |= MA35_MCR_RTSACTLV;
+	else
+		mcr &= ~MA35_MCR_RTSACTLV;
+
+	if (up->mcr & UART_MCR_AFE) {
+		serial_out(up, MA35_IER_REG, (serial_in(up, MA35_IER_REG) |
+					     MA35_IER_AUTO_RTS |
+					     MA35_IER_AUTO_CTS));
+		up->port.flags |= UPF_HARD_FLOW;
+	} else {
+		ier = serial_in(up, MA35_IER_REG);
+		ier &= ~(MA35_IER_AUTO_RTS | MA35_IER_AUTO_CTS);
+		serial_out(up, MA35_IER_REG, ier);
+		up->port.flags &= ~UPF_HARD_FLOW;
+	}
+	serial_out(up, MA35_MSR_REG, (serial_in(up, MA35_MSR_REG) |
+				     MA35_MSR_CTSACTLV));
+	serial_out(up, MA35_MCR_REG, mcr);
+}
+
+static void ma35d1serial_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	unsigned long flags;
+	u32 lcr;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	lcr = serial_in(up, MA35_LCR_REG);
+	if (break_state != 0)
+		lcr |= MA35_LCR_BREAK;
+	else
+		lcr &= ~MA35_LCR_BREAK;
+	serial_out(up, MA35_LCR_REG, lcr);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int ma35d1serial_startup(struct uart_port *port)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	int retval;
+
+	/* Reset FIFO */
+	serial_out(up, MA35_FCR_REG, MA35_FCR_TFR | MA35_FCR_RFR);
+
+	/* Clear pending interrupts */
+	serial_out(up, MA35_ISR_REG, MA35_ISR_ALL);
+
+	retval = request_irq(port->irq, ma35d1serial_interrupt, 0,
+			     dev_name(port->dev), port);
+	if (retval) {
+		dev_err(up->port.dev, "request irq failed.\n");
+		return retval;
+	}
+
+	serial_out(up, MA35_FCR_REG, serial_in(up, MA35_FCR_REG) |
+		   MA35_FCR_RFITL_4BYTES | MA35_FCR_RTSTL_8BYTES);
+	serial_out(up, MA35_LCR_REG, MA35_LCR_WLS_8BITS);
+	serial_out(up, MA35_TOR_REG, MA35_UART_RX_TOUT);
+	serial_out(up, MA35_IER_REG, MA35_IER_RTO_IEN | MA35_IER_RDA_IEN |
+		   MA35_IER_TIME_OUT_EN | MA35_IER_BUFERR_IEN);
+	return 0;
+}
+
+static void ma35d1serial_shutdown(struct uart_port *port)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+	serial_out(up, MA35_IER_REG, 0);
+	free_irq(port->irq, port);
+}
+
+static void ma35d1serial_set_termios(struct uart_port *port,
+				     struct ktermios *termios,
+				     const struct ktermios *old)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+	u32 lcr = 0;
+	unsigned long flags;
+	u32 baud, quot;
+
+	lcr = UART_LCR_WLEN(tty_get_char_size(termios->c_cflag));
+
+	if (termios->c_cflag & CSTOPB)
+		lcr |= MA35_LCR_NSB;
+	if (termios->c_cflag & PARENB)
+		lcr |= MA35_LCR_PBE;
+	if (!(termios->c_cflag & PARODD))
+		lcr |= MA35_LCR_EPE;
+	if (termios->c_cflag & CMSPAR)
+		lcr |= MA35_LCR_SPE;
+
+	baud = uart_get_baud_rate(port, termios, old,
+				  port->uartclk / MA35_BAUD_DIV_MAX,
+				  port->uartclk / MA35_BAUD_DIV_MIN);
+
+	/* MA35D1 UART baud rate equation: baudrate = UART_CLK / (quot + 2) */
+	quot = (port->uartclk / baud) - 2;
+
+	/*
+	 * Ok, we're now changing the port state.  Do it with
+	 * interrupts disabled.
+	 */
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	up->port.read_status_mask = MA35_FSR_RX_OVER_IF;
+	if (termios->c_iflag & INPCK)
+		up->port.read_status_mask |= MA35_FSR_FEF | MA35_FSR_PEF;
+	if (termios->c_iflag & (BRKINT | PARMRK))
+		up->port.read_status_mask |= MA35_FSR_BIF;
+
+	/* Characteres to ignore */
+	up->port.ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		up->port.ignore_status_mask |= MA35_FSR_FEF | MA35_FSR_PEF;
+	if (termios->c_iflag & IGNBRK) {
+		up->port.ignore_status_mask |= MA35_FSR_BIF;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			up->port.ignore_status_mask |= MA35_FSR_RX_OVER_IF;
+	}
+	if (termios->c_cflag & CRTSCTS)
+		up->mcr |= UART_MCR_AFE;
+	else
+		up->mcr &= ~UART_MCR_AFE;
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	ma35d1serial_set_mctrl(&up->port, up->port.mctrl);
+
+	serial_out(up, MA35_BAUD_REG,
+		   MA35_BAUD_MODE2 | FIELD_PREP(MA35_BAUD_MASK, quot));
+
+	serial_out(up, MA35_LCR_REG, lcr);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static const char *ma35d1serial_type(struct uart_port *port)
+{
+	return "ma35d1-uart";
+}
+
+static void ma35d1serial_config_port(struct uart_port *port, int flags)
+{
+	/*
+	 * Driver core for serial ports forces a non-zero value for port type.
+	 * Write an arbitrary value here to accommodate the serial core driver,
+	 * as ID part of UAPI is redundant.
+	 */
+	port->type = 1;
+}
+
+static int ma35d1serial_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	if (port->type != PORT_UNKNOWN && ser->type != 1)
+		return -EINVAL;
+
+	return 0;
+}
+
+static const struct uart_ops ma35d1serial_ops = {
+	.tx_empty     = ma35d1serial_tx_empty,
+	.set_mctrl    = ma35d1serial_set_mctrl,
+	.get_mctrl    = ma35d1serial_get_mctrl,
+	.stop_tx      = ma35d1serial_stop_tx,
+	.start_tx     = ma35d1serial_start_tx,
+	.stop_rx      = ma35d1serial_stop_rx,
+	.break_ctl    = ma35d1serial_break_ctl,
+	.startup      = ma35d1serial_startup,
+	.shutdown     = ma35d1serial_shutdown,
+	.set_termios  = ma35d1serial_set_termios,
+	.type         = ma35d1serial_type,
+	.config_port  = ma35d1serial_config_port,
+	.verify_port  = ma35d1serial_verify_port,
+};
+
+static const struct of_device_id ma35d1_serial_of_match[] = {
+	{ .compatible = "nuvoton,ma35d1-uart" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ma35d1_serial_of_match);
+
+#ifdef CONFIG_SERIAL_NUVOTON_MA35D1_CONSOLE
+
+static struct device_node *ma35d1serial_uart_nodes[MA35_UART_NR];
+
+static void wait_for_xmitr(struct uart_ma35d1_port *up)
+{
+	unsigned int tmout;
+
+	/* Wait up to 10ms for the character(s) to be sent. */
+	tmout = 10000;
+	while (--tmout) {
+		if (serial_in(up, MA35_FSR_REG) & MA35_FSR_TX_EMPTY)
+			break;
+		udelay(1);
+	}
+}
+
+static void ma35d1serial_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+	wait_for_xmitr(up);
+	serial_out(up, MA35_THR_REG, ch);
+}
+
+/*
+ *  Print a string to the serial port trying not to disturb
+ *  any possible real use of the port...
+ *
+ *  The console_lock must be held when we get here.
+ */
+static void ma35d1serial_console_write(struct console *co, const char *s, u32 count)
+{
+	struct uart_ma35d1_port *up = &ma35d1serial_ports[co->index];
+	unsigned long flags;
+	u32 ier;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	/*
+	 *  First save the IER then disable the interrupts
+	 */
+	ier = serial_in(up, MA35_IER_REG);
+	serial_out(up, MA35_IER_REG, 0);
+
+	uart_console_write(&up->port, s, count, ma35d1serial_console_putchar);
+
+	wait_for_xmitr(up);
+	serial_out(up, MA35_IER_REG, ier);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int __init ma35d1serial_console_setup(struct console *co, char *options)
+{
+	struct device_node *np = ma35d1serial_uart_nodes[co->index];
+	struct uart_ma35d1_port *p = &ma35d1serial_ports[co->index];
+	u32 val32[4];
+	struct uart_port *port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if ((co->index < 0) || (co->index >= MA35_UART_NR)) {
+		pr_debug("Console Port%x out of range\n", co->index);
+		return -EINVAL;
+	}
+
+	if (of_property_read_u32_array(np, "reg", val32, 4) != 0)
+		return -EINVAL;
+	p->port.iobase = val32[1];
+	p->port.membase = ioremap(p->port.iobase, MA35_UART_REG_SIZE);
+	p->port.ops = &ma35d1serial_ops;
+	p->port.line = 0;
+	p->port.uartclk = MA35_UART_CONSOLE_CLK;
+
+	port = &ma35d1serial_ports[co->index].port;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct console ma35d1serial_console = {
+	.name    = "ttyNVT",
+	.write   = ma35d1serial_console_write,
+	.device  = uart_console_device,
+	.setup   = ma35d1serial_console_setup,
+	.flags   = CON_PRINTBUFFER | CON_ENABLED,
+	.index   = -1,
+	.data    = &ma35d1serial_reg,
+};
+
+static void ma35d1serial_console_init_port(void)
+{
+	u32 i = 0;
+	struct device_node *np;
+
+	for_each_matching_node(np, ma35d1_serial_of_match) {
+		if (ma35d1serial_uart_nodes[i] == NULL) {
+			of_node_get(np);
+			ma35d1serial_uart_nodes[i] = np;
+			i++;
+			if (i == MA35_UART_NR)
+				break;
+		}
+	}
+}
+
+static int __init ma35d1serial_console_init(void)
+{
+	ma35d1serial_console_init_port();
+	register_console(&ma35d1serial_console);
+	return 0;
+}
+console_initcall(ma35d1serial_console_init);
+
+#define MA35D1SERIAL_CONSOLE    (&ma35d1serial_console)
+#else
+#define MA35D1SERIAL_CONSOLE    NULL
+#endif
+
+static struct uart_driver ma35d1serial_reg = {
+	.owner        = THIS_MODULE,
+	.driver_name  = "serial",
+	.dev_name     = "ttyNVT",
+	.major        = TTY_MAJOR,
+	.minor        = 64,
+	.cons         = MA35D1SERIAL_CONSOLE,
+	.nr           = MA35_UART_NR,
+};
+
+/*
+ * Register a set of serial devices attached to a platform device.
+ * The list is terminated with a zero flags entry, which means we expect
+ * all entries to have at least UPF_BOOT_AUTOCONF set.
+ */
+static int ma35d1serial_probe(struct platform_device *pdev)
+{
+	struct resource *res_mem;
+	struct uart_ma35d1_port *up;
+	int ret = 0;
+
+	if (pdev->dev.of_node) {
+		ret = of_alias_get_id(pdev->dev.of_node, "serial");
+		if (ret < 0) {
+			dev_err(&pdev->dev, "failed to get alias/pdev id, errno %d\n", ret);
+			return ret;
+		}
+	}
+	up = &ma35d1serial_ports[ret];
+	up->port.line = ret;
+	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res_mem)
+		return -ENODEV;
+
+	up->port.iobase = res_mem->start;
+	up->port.membase = ioremap(up->port.iobase, MA35_UART_REG_SIZE);
+	up->port.ops = &ma35d1serial_ops;
+
+	spin_lock_init(&up->port.lock);
+
+	up->clk = of_clk_get(pdev->dev.of_node, 0);
+	if (IS_ERR(up->clk)) {
+		ret = PTR_ERR(up->clk);
+		dev_err(&pdev->dev, "failed to get core clk: %d\n", ret);
+		goto err_iounmap;
+	}
+
+	ret = clk_prepare_enable(up->clk);
+	if (ret)
+		goto err_iounmap;
+
+	if (up->port.line != 0)
+		up->port.uartclk = clk_get_rate(up->clk);
+
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		goto err_clk_disable;
+
+	up->port.irq = ret;
+	up->port.dev = &pdev->dev;
+	up->port.flags = UPF_BOOT_AUTOCONF;
+
+	platform_set_drvdata(pdev, up);
+
+	ret = uart_add_one_port(&ma35d1serial_reg, &up->port);
+	if (ret < 0)
+		goto err_free_irq;
+
+	return 0;
+
+err_free_irq:
+	free_irq(up->port.irq, &up->port);
+
+err_clk_disable:
+	clk_disable_unprepare(up->clk);
+
+err_iounmap:
+	iounmap(up->port.membase);
+	return ret;
+}
+
+/*
+ * Remove serial ports registered against a platform device.
+ */
+static int ma35d1serial_remove(struct platform_device *dev)
+{
+	struct uart_port *port = platform_get_drvdata(dev);
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+	uart_remove_one_port(&ma35d1serial_reg, port);
+	clk_disable_unprepare(up->clk);
+	return 0;
+}
+
+static int ma35d1serial_suspend(struct platform_device *dev, pm_message_t state)
+{
+	struct uart_port *port = platform_get_drvdata(dev);
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+	uart_suspend_port(&ma35d1serial_reg, &up->port);
+	if (up->port.line == 0) {
+		up->console_baud_rate = serial_in(up, MA35_BAUD_REG);
+		up->console_line = serial_in(up, MA35_LCR_REG);
+		up->console_int = serial_in(up, MA35_IER_REG);
+	}
+	return 0;
+}
+
+static int ma35d1serial_resume(struct platform_device *dev)
+{
+	struct uart_port *port = platform_get_drvdata(dev);
+	struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+	if (up->port.line == 0) {
+		serial_out(up, MA35_BAUD_REG, up->console_baud_rate);
+		serial_out(up, MA35_LCR_REG, up->console_line);
+		serial_out(up, MA35_IER_REG, up->console_int);
+	}
+	uart_resume_port(&ma35d1serial_reg, &up->port);
+	return 0;
+}
+
+static struct platform_driver ma35d1serial_driver = {
+	.probe      = ma35d1serial_probe,
+	.remove     = ma35d1serial_remove,
+	.suspend    = ma35d1serial_suspend,
+	.resume     = ma35d1serial_resume,
+	.driver     = {
+		.name   = "ma35d1-uart",
+		.owner  = THIS_MODULE,
+		.of_match_table = of_match_ptr(ma35d1_serial_of_match),
+	},
+};
+
+static int __init ma35d1serial_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&ma35d1serial_reg);
+	if (ret)
+		return ret;
+	ret = platform_driver_register(&ma35d1serial_driver);
+	if (ret)
+		uart_unregister_driver(&ma35d1serial_reg);
+	return ret;
+}
+
+static void __exit ma35d1serial_exit(void)
+{
+	platform_driver_unregister(&ma35d1serial_driver);
+	uart_unregister_driver(&ma35d1serial_reg);
+}
+
+module_init(ma35d1serial_init);
+module_exit(ma35d1serial_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MA35D1 serial driver");