[PATCH 1/4] ARM/serial: at91: move machine quirk into machine
Nicolas Ferre
nicolas.ferre at atmel.com
Tue Nov 5 06:10:04 EST 2013
On 05/11/2013 10:28, Linus Walleij :
> This removes the dependency on <mach/gpio.h> from the AT91 serial
> driver by adding an mctrl callback quirk.
>
> Long term it is better if the driver calls the generic GPIO
> interface (gpio_set_value()), but this gets a hairy cross-depency
> into the machine-local headers out of the way for now.
>
> Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
Linus,
I do think that we have to remove this dependency but the only thing
that embarrasses me is that your change only allows non-DT at91rm9200 to
work well with its RTS line.
If we use Device Tree with this product (which is actually possible) we
don't have this feature available anymore...
A possible solution can be to give an optional RTS pin specification to
the DT binding and to the pdata structure, if defined it can be used in
the atmel_set_mctrl() function. This way we do not have a special
behavior for at91rm9200 anymore. For the use of specialized AT91 gpio
functions, well, we can implement the move to gpiolib.
What do you think Linus? Is there a trend to remove the calls to GPIO
functions in drivers?
Best regards,
> ---
> Greg, if you're OK with this approach please give me an ACK
> so I can take this through the ARM SoC or GPIO tree in the end.
> ---
> arch/arm/mach-at91/at91rm9200_devices.c | 14 ++++++++++++++
> drivers/tty/serial/atmel_serial.c | 19 ++++---------------
> include/linux/platform_data/atmel.h | 1 +
> 3 files changed, 19 insertions(+), 15 deletions(-)
>
> diff --git a/arch/arm/mach-at91/at91rm9200_devices.c b/arch/arm/mach-at91/at91rm9200_devices.c
> index 3ebc9792560c..3ce6ba6341ed 100644
> --- a/arch/arm/mach-at91/at91rm9200_devices.c
> +++ b/arch/arm/mach-at91/at91rm9200_devices.c
> @@ -12,6 +12,7 @@
> */
> #include <asm/mach/arch.h>
> #include <asm/mach/map.h>
> +#include <asm/termios.h>
>
> #include <linux/dma-mapping.h>
> #include <linux/gpio.h>
> @@ -957,9 +958,22 @@ static struct resource uart0_resources[] = {
> },
> };
>
> +static void uart0_set_mctrl(unsigned int mctrl)
> +{
> + /*
> + * AT91RM9200 Errata #39: RTS0 is not internally connected
> + * to PA21. We need to drive the pin manually.
> + */
> + if (mctrl & TIOCM_RTS)
> + at91_set_gpio_value(AT91_PIN_PA21, 0);
> + else
> + at91_set_gpio_value(AT91_PIN_PA21, 1);
> +}
> +
> static struct atmel_uart_data uart0_data = {
> .use_dma_tx = 1,
> .use_dma_rx = 1,
> + .set_mctrl = uart0_set_mctrl,
> };
>
> static u64 uart0_dmamask = DMA_BIT_MASK(32);
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index d067285a2d20..5b29e3152d7e 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -47,7 +47,6 @@
>
> #ifdef CONFIG_ARM
> #include <mach/cpu.h>
> -#include <asm/gpio.h>
> #endif
>
> #define PDC_BUFFER_SIZE 512
> @@ -176,6 +175,7 @@ struct atmel_uart_port {
> void (*schedule_tx)(struct uart_port *port);
> void (*release_rx)(struct uart_port *port);
> void (*release_tx)(struct uart_port *port);
> + void (*set_mctrl)(unsigned int mctrl);
> };
>
> static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
> @@ -300,20 +300,8 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
> unsigned int mode;
> struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
>
> -#ifdef CONFIG_ARCH_AT91RM9200
> - if (cpu_is_at91rm9200()) {
By removing this call, you can also remove
#include <mach/cpu.h>
as well (maybe in another patch).
> - /*
> - * AT91RM9200 Errata #39: RTS0 is not internally connected
> - * to PA21. We need to drive the pin manually.
> - */
> - if (port->mapbase == AT91RM9200_BASE_US0) {
> - if (mctrl & TIOCM_RTS)
> - at91_set_gpio_value(AT91_PIN_PA21, 0);
> - else
> - at91_set_gpio_value(AT91_PIN_PA21, 1);
> - }
> - }
> -#endif
> + if (atmel_port->set_mctrl)
> + atmel_port->set_mctrl(mctrl);
>
> if (mctrl & TIOCM_RTS)
> control |= ATMEL_US_RTSEN;
> @@ -2365,6 +2353,7 @@ static int atmel_serial_probe(struct platform_device *pdev)
> port = &atmel_ports[ret];
> port->backup_imr = 0;
> port->uart.line = ret;
> + port->set_mctrl = pdata->set_mctrl;
>
> ret = atmel_init_port(port, pdev);
> if (ret)
> diff --git a/include/linux/platform_data/atmel.h b/include/linux/platform_data/atmel.h
> index cea9f70133c5..59991aae0217 100644
> --- a/include/linux/platform_data/atmel.h
> +++ b/include/linux/platform_data/atmel.h
> @@ -84,6 +84,7 @@ struct atmel_uart_data {
> short use_dma_rx; /* use receive DMA? */
> void __iomem *regs; /* virt. base address, if any */
> struct serial_rs485 rs485; /* rs485 settings */
> + void (*set_mctrl)(unsigned int mctrl); /* mctrl callback */
> };
>
> /* Touchscreen Controller */
>
--
Nicolas Ferre
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