[PATCH 1/4] ARM/serial: at91: move machine quirk into machine
From: Nicolas Ferre <hidden>
Date: 2013-11-05 11:10:11
Also in:
linux-gpio, linux-serial
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@linuxfoundation.org> Signed-off-by: Linus Walleij <redacted>
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,
quoted hunk ↗ jump to hunk
--- 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).
quoted hunk ↗ jump to hunk
- /* - * 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