[RFC] serial: sc16is7xx: Use DT sub-nodes for UART ports

[RFC] serial: sc16is7xx: Use DT sub-nodes for UART ports

[Andreas Färber]

This is to allow using serdev.

Signed-off-by: Andreas Färber <afaerber@suse.de>
---
 drivers/tty/serial/sc16is7xx.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 243c96025053..ad7267274f65 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1213,9 +1213,31 @@ static int sc16is7xx_probe(struct device *dev,
 			SC16IS7XX_IOCONTROL_SRESET_BIT);
 
 	for (i = 0; i < devtype->nr_uart; ++i) {
+#ifdef CONFIG_OF
+		struct device_node *np;
+		struct platform_device *pdev;
+		char name[6] = "uartx";
+#endif
+
 		s->p[i].line		= i;
 		/* Initialize port data */
+#ifdef CONFIG_OF
+		name[4] = '0' + i;
+		np = of_get_child_by_name(dev->of_node, name);
+		if (IS_ERR(np)) {
+			ret = PTR_ERR(np);
+			goto out_ports;
+		}
+		pdev = of_platform_device_create(np, NULL, dev);
+		if (IS_ERR(pdev)) {
+			ret = PTR_ERR(pdev);
+			goto out_ports;
+		}
+		platform_set_drvdata(pdev, dev_get_drvdata(dev));
+		s->p[i].port.dev	= &pdev->dev;
+#else
 		s->p[i].port.dev	= dev;
+#endif
 		s->p[i].port.irq	= irq;
 		s->p[i].port.type	= PORT_SC16IS7XX;
 		s->p[i].port.fifosize	= SC16IS7XX_FIFO_SIZE;
@@ -1271,6 +1293,9 @@ static int sc16is7xx_probe(struct device *dev,
 	for (i--; i >= 0; i--) {
 		uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
 		clear_bit(s->p[i].port.line, &sc16is7xx_lines);
+#ifdef CONFIG_OF
+		of_platform_device_destroy(s->p[i].port.dev, NULL);
+#endif
 	}
 
 #ifdef CONFIG_GPIOLIB
-- 
2.16.4

Re: [RFC] serial: sc16is7xx: Use DT sub-nodes for UART ports

[Andreas Färber]

Am 06.08.2018 um 01:26 schrieb Andreas Färber:
> This is to allow using serdev.
> 
> Signed-off-by: Andreas Färber <afaerber@suse.de>
> ---
>  drivers/tty/serial/sc16is7xx.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
> index 243c96025053..ad7267274f65 100644
> --- a/drivers/tty/serial/sc16is7xx.c
> +++ b/drivers/tty/serial/sc16is7xx.c
> @@ -1213,9 +1213,31 @@ static int sc16is7xx_probe(struct device *dev,
>  			SC16IS7XX_IOCONTROL_SRESET_BIT);
>  
>  	for (i = 0; i < devtype->nr_uart; ++i) {
> +#ifdef CONFIG_OF

Looks like this and below need to be CONFIG_OF_ADDRESS (build failure
reported for sparc).

Regards,
Andreas

> +		struct device_node *np;
> +		struct platform_device *pdev;
> +		char name[6] = "uartx";
> +#endif
> +
>  		s->p[i].line		= i;
>  		/* Initialize port data */
> +#ifdef CONFIG_OF
> +		name[4] = '0' + i;
> +		np = of_get_child_by_name(dev->of_node, name);
> +		if (IS_ERR(np)) {
> +			ret = PTR_ERR(np);
> +			goto out_ports;
> +		}
> +		pdev = of_platform_device_create(np, NULL, dev);
> +		if (IS_ERR(pdev)) {
> +			ret = PTR_ERR(pdev);
> +			goto out_ports;
> +		}
> +		platform_set_drvdata(pdev, dev_get_drvdata(dev));
> +		s->p[i].port.dev	= &pdev->dev;
> +#else
>  		s->p[i].port.dev	= dev;
> +#endif
>  		s->p[i].port.irq	= irq;
>  		s->p[i].port.type	= PORT_SC16IS7XX;
>  		s->p[i].port.fifosize	= SC16IS7XX_FIFO_SIZE;
> @@ -1271,6 +1293,9 @@ static int sc16is7xx_probe(struct device *dev,
>  	for (i--; i >= 0; i--) {
>  		uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
>  		clear_bit(s->p[i].port.line, &sc16is7xx_lines);
> +#ifdef CONFIG_OF
> +		of_platform_device_destroy(s->p[i].port.dev, NULL);
> +#endif
>  	}
>  
>  #ifdef CONFIG_GPIOLIB

-- 
SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)

Re: [RFC] serial: sc16is7xx: Use DT sub-nodes for UART ports

[Rob Herring]

On Sun, Aug 5, 2018 at 5:27 PM Andreas Färber <afaerber@suse.de> wrote:
>
> This is to allow using serdev.
>
> Signed-off-by: Andreas Färber <afaerber@suse.de>
> ---
>  drivers/tty/serial/sc16is7xx.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
>
> diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
> index 243c96025053..ad7267274f65 100644
> --- a/drivers/tty/serial/sc16is7xx.c
> +++ b/drivers/tty/serial/sc16is7xx.c
> @@ -1213,9 +1213,31 @@ static int sc16is7xx_probe(struct device *dev,
>                         SC16IS7XX_IOCONTROL_SRESET_BIT);
>
>         for (i = 0; i < devtype->nr_uart; ++i) {
> +#ifdef CONFIG_OF
> +               struct device_node *np;
> +               struct platform_device *pdev;
> +               char name[6] = "uartx";
> +#endif
> +
>                 s->p[i].line            = i;
>                 /* Initialize port data */
> +#ifdef CONFIG_OF
> +               name[4] = '0' + i;
> +               np = of_get_child_by_name(dev->of_node, name);
> +               if (IS_ERR(np)) {
> +                       ret = PTR_ERR(np);
> +                       goto out_ports;
> +               }
> +               pdev = of_platform_device_create(np, NULL, dev);

Ideally, you would use of_platform_default_populate here. I think
you'd have to add a compatible to the child nodes, but that wouldn't
be a bad thing. I could envision that the child nodes ultimately
become their own driver utilizing the standard 8250 driver and a
compatible string would be needed in that case.

You'd then have to loop over each child of 'dev' instead of the DT nodes.

> +               if (IS_ERR(pdev)) {
> +                       ret = PTR_ERR(pdev);
> +                       goto out_ports;
> +               }
> +               platform_set_drvdata(pdev, dev_get_drvdata(dev));
> +               s->p[i].port.dev        = &pdev->dev;
> +#else
>                 s->p[i].port.dev        = dev;
> +#endif
>                 s->p[i].port.irq        = irq;
>                 s->p[i].port.type       = PORT_SC16IS7XX;
>                 s->p[i].port.fifosize   = SC16IS7XX_FIFO_SIZE;

Re: [RFC] serial: sc16is7xx: Use DT sub-nodes for UART ports

[Andreas Färber]

Am 10.08.2018 um 19:34 schrieb Rob Herring:
> On Sun, Aug 5, 2018 at 5:27 PM Andreas Färber <afaerber@suse.de> wrote:
>>
>> This is to allow using serdev.
>>
>> Signed-off-by: Andreas Färber <afaerber@suse.de>
>> ---
>>  drivers/tty/serial/sc16is7xx.c | 25 +++++++++++++++++++++++++
>>  1 file changed, 25 insertions(+)
>>
>> diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
>> index 243c96025053..ad7267274f65 100644
>> --- a/drivers/tty/serial/sc16is7xx.c
>> +++ b/drivers/tty/serial/sc16is7xx.c
>> @@ -1213,9 +1213,31 @@ static int sc16is7xx_probe(struct device *dev,
>>                         SC16IS7XX_IOCONTROL_SRESET_BIT);
>>
>>         for (i = 0; i < devtype->nr_uart; ++i) {
>> +#ifdef CONFIG_OF
>> +               struct device_node *np;
>> +               struct platform_device *pdev;
>> +               char name[6] = "uartx";
>> +#endif
>> +
>>                 s->p[i].line            = i;
>>                 /* Initialize port data */
>> +#ifdef CONFIG_OF
>> +               name[4] = '0' + i;
>> +               np = of_get_child_by_name(dev->of_node, name);
>> +               if (IS_ERR(np)) {
>> +                       ret = PTR_ERR(np);
>> +                       goto out_ports;
>> +               }
>> +               pdev = of_platform_device_create(np, NULL, dev);
> 
> Ideally, you would use of_platform_default_populate here. I think
> you'd have to add a compatible to the child nodes, but that wouldn't
> be a bad thing. I could envision that the child nodes ultimately
> become their own driver utilizing the standard 8250 driver and a
> compatible string would be needed in that case.

Separate compatibles would mean separate drivers.

Unlike your DUART example this is not an MMIO device that we can easily
split but a SPI slave (well, regmap due to some I2C models).

I don't see how separate drivers could work, given that the whole
spi_device has a single interrupt for all functions of this device.

That left me with this ugly but working construct.

Is the uartX naming correct, or should it be serialX?

Regards,
Andreas

> 
> You'd then have to loop over each child of 'dev' instead of the DT nodes.
> 
>> +               if (IS_ERR(pdev)) {
>> +                       ret = PTR_ERR(pdev);
>> +                       goto out_ports;
>> +               }
>> +               platform_set_drvdata(pdev, dev_get_drvdata(dev));
>> +               s->p[i].port.dev        = &pdev->dev;
>> +#else
>>                 s->p[i].port.dev        = dev;
>> +#endif
>>                 s->p[i].port.irq        = irq;
>>                 s->p[i].port.type       = PORT_SC16IS7XX;
>>                 s->p[i].port.fifosize   = SC16IS7XX_FIFO_SIZE;


-- 
SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)

Re: [RFC] serial: sc16is7xx: Use DT sub-nodes for UART ports

[Rob Herring]

On Fri, Aug 10, 2018 at 11:45 AM Andreas Färber <afaerber@suse.de> wrote:
>
> Am 10.08.2018 um 19:34 schrieb Rob Herring:
> > On Sun, Aug 5, 2018 at 5:27 PM Andreas Färber <afaerber@suse.de> wrote:
> >>
> >> This is to allow using serdev.
> >>
> >> Signed-off-by: Andreas Färber <afaerber@suse.de>
> >> ---
> >>  drivers/tty/serial/sc16is7xx.c | 25 +++++++++++++++++++++++++
> >>  1 file changed, 25 insertions(+)
> >>
> >> diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
> >> index 243c96025053..ad7267274f65 100644
> >> --- a/drivers/tty/serial/sc16is7xx.c
> >> +++ b/drivers/tty/serial/sc16is7xx.c
> >> @@ -1213,9 +1213,31 @@ static int sc16is7xx_probe(struct device *dev,
> >>                         SC16IS7XX_IOCONTROL_SRESET_BIT);
> >>
> >>         for (i = 0; i < devtype->nr_uart; ++i) {
> >> +#ifdef CONFIG_OF
> >> +               struct device_node *np;
> >> +               struct platform_device *pdev;
> >> +               char name[6] = "uartx";
> >> +#endif
> >> +
> >>                 s->p[i].line            = i;
> >>                 /* Initialize port data */
> >> +#ifdef CONFIG_OF
> >> +               name[4] = '0' + i;
> >> +               np = of_get_child_by_name(dev->of_node, name);
> >> +               if (IS_ERR(np)) {
> >> +                       ret = PTR_ERR(np);
> >> +                       goto out_ports;
> >> +               }
> >> +               pdev = of_platform_device_create(np, NULL, dev);
> >
> > Ideally, you would use of_platform_default_populate here. I think
> > you'd have to add a compatible to the child nodes, but that wouldn't
> > be a bad thing. I could envision that the child nodes ultimately
> > become their own driver utilizing the standard 8250 driver and a
> > compatible string would be needed in that case.
>
> Separate compatibles would mean separate drivers.

No. Having a compatible doesn't mean you have to have a driver.

> Unlike your DUART example this is not an MMIO device that we can easily
> split but a SPI slave (well, regmap due to some I2C models).

A SPI slave could provide a regmap, right?

> I don't see how separate drivers could work, given that the whole
> spi_device has a single interrupt for all functions of this device.

A shared interrupt or a parent driver that creates an irqchip like MFD
drivers often do.

>
> That left me with this ugly but working construct.

In any case, I'm was suggesting that you do any of this now. I just
want the binding to be designed to work either way.

> Is the uartX naming correct, or should it be serialX?

Ah, yes. Should be serial@... I'm fine if both the parent and child
are named serial@...

Rob