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@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
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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