Re: [PATCH v3 6/6] tty/serial: atmel: changed the driver to work under at91-usart mfd

[Radu Pirea <radu.pirea@microchip.com>]

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On Mon, 2018-05-14 at 12:57 +0200, Richard Genoud wrote:
> Hi,
> 
> On 11/05/2018 12:38, Radu Pirea wrote:
> > This patch modifies the place where resources and device tree
> > properties
> > are searched.
> > 
> > Signed-off-by: Radu Pirea <radu.pirea@microchip.com>
> > ---
> >  drivers/tty/serial/Kconfig        |  1 +
> >  drivers/tty/serial/atmel_serial.c | 29 +++++++++++++++----------
> > ----
> >  2 files changed, 16 insertions(+), 14 deletions(-)
> > 
> > diff --git a/drivers/tty/serial/Kconfig
> > b/drivers/tty/serial/Kconfig
> > index 3682fd3e960c..25e55332f8b1 100644
> > --- a/drivers/tty/serial/Kconfig
> > +++ b/drivers/tty/serial/Kconfig
> > @@ -119,6 +119,7 @@ config SERIAL_ATMEL
> >  	depends on ARCH_AT91 || COMPILE_TEST
> >  	select SERIAL_CORE
> >  	select SERIAL_MCTRL_GPIO if GPIOLIB
> > +	select MFD_AT91_USART
> >  	help
> >  	  This enables the driver for the on-chip UARTs of the
> > Atmel
> >  	  AT91 processors.
> > diff --git a/drivers/tty/serial/atmel_serial.c
> > b/drivers/tty/serial/atmel_serial.c
> > index df46a9e88c34..6b4494352853 100644
> > --- a/drivers/tty/serial/atmel_serial.c
> > +++ b/drivers/tty/serial/atmel_serial.c
> > @@ -193,8 +193,8 @@ static struct console atmel_console;
> >  
> >  #if defined(CONFIG_OF)
> >  static const struct of_device_id atmel_serial_dt_ids[] = {
> > -	{ .compatible = "atmel,at91rm9200-usart" },
> > -	{ .compatible = "atmel,at91sam9260-usart" },
> > +	{ .compatible = "atmel,at91rm9200-usart-serial" },
> > +	{ .compatible = "atmel,at91sam9260-usart-serial" },
> >  	{ /* sentinel */ }
> >  };
> >  #endif
> > @@ -1631,7 +1631,7 @@ static void atmel_tasklet_tx_func(unsigned
> > long data)
> >  static void atmel_init_property(struct atmel_uart_port
> > *atmel_port,
> >  				struct platform_device *pdev)
> >  {
> > -	struct device_node *np = pdev->dev.of_node;
> > +	struct device_node *np = pdev->dev.parent->of_node;
> >  
> >  	/* DMA/PDC usage specification */
> >  	if (of_property_read_bool(np, "atmel,use-dma-rx")) {
> > @@ -2223,7 +2223,8 @@ static const char *atmel_type(struct
> > uart_port *port)
> >  static void atmel_release_port(struct uart_port *port)
> >  {
> >  	struct platform_device *pdev = to_platform_device(port-
> > >dev);
> > -	int size = pdev->resource[0].end - pdev->resource[0].start 
> > + 1;
> > +	int size = to_platform_device(pdev->dev.parent)-
> > >resource[0].end -
> > +		to_platform_device(pdev->dev.parent)-
> > >resource[0].start + 1;
> 
> I think it may be simpler with something like:
> +	struct platform_device *mfd_pdev = to_platform_device(port-
> >dev->parent);
> +	int size = mfd_pdev->resource[0].end - mfd_pdev-
> >resource[0].start + 1;
> 
> >  
> >  	release_mem_region(port->mapbase, size);
> >  
> > @@ -2239,7 +2240,8 @@ static void atmel_release_port(struct
> > uart_port *port)
> >  static int atmel_request_port(struct uart_port *port)
> >  {
> >  	struct platform_device *pdev = to_platform_device(port-
> > >dev);
> > -	int size = pdev->resource[0].end - pdev->resource[0].start 
> > + 1;
> > +	int size = to_platform_device(pdev->dev.parent)-
> > >resource[0].end -
> > +		to_platform_device(pdev->dev.parent)-
> > >resource[0].start + 1;
> >  
> 
> ditto
> 
> >  	if (!request_mem_region(port->mapbase, size,
> > "atmel_serial"))
> >  		return -EBUSY;
> > @@ -2345,23 +2347,23 @@ static int atmel_init_port(struct
> > atmel_uart_port *atmel_port,
> 
> Here, we could also add:
> +	struct device *mfd_dev = pdev->dev.parent;
> +	struct platform_device *mfd_pdev =
> to_platform_device(mfd_dev);
> 
> >  	atmel_init_property(atmel_port, pdev);
> >  	atmel_set_ops(port);
> >  
> > -	uart_get_rs485_mode(&pdev->dev, &port->rs485);
> > +	uart_get_rs485_mode(pdev->dev.parent, &port->rs485);
> 
> ...and use them here
> 
> >  
> >  	port->iotype		= UPIO_MEM;
> >  	port->flags		= UPF_BOOT_AUTOCONF |
> > UPF_IOREMAP;
> >  	port->ops		= &atmel_pops;
> >  	port->fifosize		= 1;
> >  	port->dev		= &pdev->dev;
> > -	port->mapbase	= pdev->resource[0].start;
> > -	port->irq	= pdev->resource[1].start;
> > +	port->mapbase		= to_platform_device(pdev-
> > >dev.parent)->resource[0].start;
> > +	port->irq		= to_platform_device(pdev-
> > >dev.parent)->resource[1].start;
> 
> and here
> I think it would be easier to read.
> 
> >  	port->rs485_config	= atmel_config_rs485;
> > -	port->membase	= NULL;
> > +	port->membase		= NULL;
> >  
> >  	memset(&atmel_port->rx_ring, 0, sizeof(atmel_port-
> > >rx_ring));
> >  
> >  	/* for console, the clock could already be configured */
> >  	if (!atmel_port->clk) {
> > -		atmel_port->clk = clk_get(&pdev->dev, "usart");
> > +		atmel_port->clk = clk_get(pdev->dev.parent,
> > "usart");
> 
> and here
> 
> >  		if (IS_ERR(atmel_port->clk)) {
> >  			ret = PTR_ERR(atmel_port->clk);
> >  			atmel_port->clk = NULL;
> > @@ -2656,7 +2658,7 @@ static void atmel_serial_probe_fifos(struct
> > atmel_uart_port *atmel_port,
> >  	atmel_port->rts_low = 0;
> >  	atmel_port->rts_high = 0;
> >  
> > -	if (of_property_read_u32(pdev->dev.of_node,
> > +	if (of_property_read_u32(pdev->dev.parent->of_node,
> >  				 "atmel,fifo-size",
> >  				 &atmel_port->fifo_size))
> >  		return;
> > @@ -2694,11 +2696,10 @@ static void atmel_serial_probe_fifos(struct
> > atmel_uart_port *atmel_port,
> >  static int atmel_serial_probe(struct platform_device *pdev)
> >  {
> >  	struct atmel_uart_port *atmel_port;
> > -	struct device_node *np = pdev->dev.of_node;
> > +	struct device_node *np = pdev->dev.parent->of_node;
> >  	void *data;
> >  	int ret = -ENODEV;
> >  	bool rs485_enabled;
> > -
> 
> I think this line feed wasn't so bad.
> 
> >  	BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE &
> > (ATMEL_SERIAL_RINGSIZE - 1));
> >  
> >  	ret = of_alias_get_id(np, "serial");
> > @@ -2845,7 +2846,7 @@ static struct platform_driver
> > atmel_serial_driver = {
> >  	.suspend	= atmel_serial_suspend,
> >  	.resume		= atmel_serial_resume,
> >  	.driver		= {
> > -		.name			= "atmel_usart",
> > +		.name			=
> > "atmel_usart_serial",
> >  		.of_match_table		=
> > of_match_ptr(atmel_serial_dt_ids),
> >  	},
> >  };
> > 
> 
> After your patch, the DMA is not selected anymore:
> atmel_usart_serial atmel_usart_serial.0.auto: TX channel not
> available, switch to pio
> instead of:
> atmel_usart fffff200.serial: using dma1chan2 for tx DMA transfers
> 
Fixed.
> And the kernel doesn't log anymore on the serial console, despite the
> loglevel=8
> (after reverting this series, the kernel logs reappears on the serial
> console)
> 
Which serial are you using as console? 
> (tests done on sam9g35)
> 
I will consider the rest of suggestions. 
> regards,
> Richard
> 

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