tty/serial: Add helpers to use GPIOs to control modem lines and implement atmel_serial.c

This patch add some helpers to control modem lines (CTS/RTS/DSR...) via GPIO.
This will be useful for many boards which have a serial controller that only handle CTS/RTS pins (or even just RX/TX).

Signed-off-by Richard Genoud <[email protected]>

Quoted 5 lines

This patch add some helpers to control modem lines (CTS/RTS/DSR...) via GPIO.
This will be useful for many boards which have a serial controller that only handle CTS/RTS pins (or even just RX/TX).

Quoted 1 line

Signed-off-by Richard Genoud <[email protected]>

Acked-by Greg Kroah-Hartman <[email protected]>

I can't take this series through my tty tree as the non-tty patches don't apply, so feel free to take them through whatever tree is needed.

greg k-h

2014-03-18 0:23 GMT+01:00 Greg Kroah-Hartman <[email protected]>:

Quoted 6 lines · Richard Genoud

Quoted 5 lines

This patch add some helpers to control modem lines (CTS/RTS/DSR...) via GPIO.
This will be useful for many boards which have a serial controller that only handle CTS/RTS pins (or even just RX/TX).

Quoted 8 lines

Quoted 1 line

Signed-off-by Richard Genoud <[email protected]>

Acked-by Greg Kroah-Hartman <[email protected]>

I can't take this series through my tty tree as the non-tty patches don't apply, so feel free to take them through whatever tree is needed.

greg k-h

To clarify things, here are the patches that this series needs, on top of 3.14-rc6:
tty/tty-next tree: ddaa603739fe tty/serial: at91: use dev_err instead of printk tty/tty-next tree: a3c1fa99f4d2 tty/serial: at91: remove unused open/close hooks ukl/dropmachtimexh-fixup: 354e57f3a0a2 ARM/serial: at91: switch atmel serial to use gpiolib
tree unknown: [PATCH v3 5/7] ARM: at91: gpio: implement get_direction pinctrl/for-next: 8af584b86836 pinctrl: at91: implement get_direction

after that, the series applies cleanly.
the patch "[PATCH v3 5/7] ARM: at91: gpio: implement get_direction" has been acked-by Linus, but I didn't found it in a tree.

onto next-20140318, it only needs "[PATCH v3 5/7] ARM: at91: gpio:
implement get_direction" .

trees:
tty: git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
ukl: git://git.pengutronix.de/git/ukl/linux.git
pinctrl: git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl.git

Richard.

Quoted 5 lines · Richard Genoud

This patch add some helpers to control modem lines (CTS/RTS/DSR...) via GPIO.
This will be useful for many boards which have a serial controller that only handle CTS/RTS pins (or even just RX/TX).

Quoted 1 line

Signed-off-by Richard Genoud <[email protected]>

Acked-by Greg Kroah-Hartman <[email protected]>

I can't take this series through my tty tree as the non-tty patches don't apply, so feel free to take them through whatever tree is needed.

greg k-h

Quoted 13 lines · Greg Kroah-Hartman

Quoted 6 lines · Richard Genoud

This patch add some helpers to control modem lines (CTS/RTS/DSR...) via GPIO.
This will be useful for many boards which have a serial controller that only handle CTS/RTS pins (or even just RX/TX).

Signed-off-by Richard Genoud <[email protected]>

Acked-by Greg Kroah-Hartman <[email protected]>

I can't take this series through my tty tree as the non-tty patches don't apply, so feel free to take them through whatever tree is needed.

Quoted 2 lines

greg k-h

I guess this series won't make it for 3.15, as it doesn't apply on any tree. However, I'd like to know if I did something wrong, or if there's no solution when a series depends on several patches that are in different trees ?

Quoted 14 lines · Greg Kroah-Hartman

Quoted 13 lines · Richard Genoud

Quoted 6 lines

This patch add some helpers to control modem lines (CTS/RTS/DSR...) via GPIO.
This will be useful for many boards which have a serial controller that only handle CTS/RTS pins (or even just RX/TX).

Signed-off-by Richard Genoud <[email protected]>

Acked-by Greg Kroah-Hartman <[email protected]>

I can't take this series through my tty tree as the non-tty patches don't apply, so feel free to take them through whatever tree is needed.

Quoted 7 lines

Quoted 2 lines

greg k-h

I guess this series won't make it for 3.15, as it doesn't apply on any tree. However, I'd like to know if I did something wrong, or if there's no solution when a series depends on several patches that are in different trees ?

That's a hard problem, either wait a release cycle for everything to get merged properly (like should be done in time for 3.15-rc1 now) and then submit the code, or ask for different maintainers to either allow other trees to take the patches, put the patches in different trees at the same time, or have "topic branches" that different maintainers can pull from.

Care to send me the patches after 3.15-rc1 is out, as there should not be any dependancy issues then, right?

greg k-h

This patch add some helpers to control modem lines (CTS/RTS/DSR...) via GPIO.
This will be useful for many boards which have a serial controller that only handle CTS/RTS pins (or even just RX/TX).

Signed-off-by Richard Genoud <[email protected]>

drivers/tty/serial/serial_mctrl_gpio.c new file +58 -0

+
+struct mctrl_gpios {
+	struct gpio_desc *gpio[UART_GPIO_MAX];
+};
+
+static const struct {
+	const char *name;
+	unsigned int mctrl;
+	bool dir_out;
+} mctrl_gpios_desc[UART_GPIO_MAX] = {
+	{ "cts", TIOCM_CTS, false, },
+	{ "dsr", TIOCM_DSR, false, },
+	{ "dcd", TIOCM_CD, false, },
+	{ "rng", TIOCM_RNG, false, },
+	{ "rts", TIOCM_RTS, true, },
+	{ "dtr", TIOCM_DTR, true, },
+	{ "out1", TIOCM_OUT1, true, },
+	{ "out2", TIOCM_OUT2, true, },
+};
+
+void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
+{
+	enum mctrl_gpio_idx i;
+
+	if (IS_ERR_OR_NULL(gpios))
+		return;
+
+	for (i = 0; i < UART_GPIO_MAX; i++)
+		if (!IS_ERR_OR_NULL(gpios->gpio[i]) &&
+		    mctrl_gpios_desc[i].dir_out)
+			gpiod_set_value(gpios->gpio[i],
+					!!(mctrl & mctrl_gpios_desc[i].mctrl));
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_set);
+
+struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
+				      enum mctrl_gpio_idx gidx)
+{
+	if (!IS_ERR_OR_NULL(gpios) && !IS_ERR_OR_NULL(gpios->gpio[gidx]))
+		return gpios->gpio[gidx];
+	else
+		return NULL;
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_to_gpiod);
+
+unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
+{
+	enum mctrl_gpio_idx i;
+
+	/*
+	 * return it unchanged if the structure is not allocated
+	 */
+	if (IS_ERR_OR_NULL(gpios))
+		return *mctrl;
+
+	for (i = 0; i < UART_GPIO_MAX; i++) {
+		if (!IS_ERR_OR_NULL(gpios->gpio[i]) &&
+		    !mctrl_gpios_desc[i].dir_out) {

Quoted 6 lines

This patch add some helpers to control modem lines (CTS/RTS/DSR...) via GPIO.
This will be useful for many boards which have a serial controller that only handle CTS/RTS pins (or even just RX/TX).

Signed-off-by Richard Genoud <[email protected]>

....

Quoted 58 lines

drivers/tty/serial/serial_mctrl_gpio.c new file +58 -0

+
+struct mctrl_gpios {
+     struct gpio_desc *gpio[UART_GPIO_MAX];
+};
+
+static const struct {
+     const char *name;
+     unsigned int mctrl;
+     bool dir_out;
+} mctrl_gpios_desc[UART_GPIO_MAX] = {
+     { "cts", TIOCM_CTS, false, },
+     { "dsr", TIOCM_DSR, false, },
+     { "dcd", TIOCM_CD, false, },
+     { "rng", TIOCM_RNG, false, },
+     { "rts", TIOCM_RTS, true, },
+     { "dtr", TIOCM_DTR, true, },
+     { "out1", TIOCM_OUT1, true, },
+     { "out2", TIOCM_OUT2, true, },
+};
+
+void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
+{
+     enum mctrl_gpio_idx i;
+
+     if (IS_ERR_OR_NULL(gpios))
+             return;
+
+     for (i = 0; i < UART_GPIO_MAX; i++)
+             if (!IS_ERR_OR_NULL(gpios->gpio[i]) &&
+                 mctrl_gpios_desc[i].dir_out)
+                     gpiod_set_value(gpios->gpio[i],
+                                     !!(mctrl & mctrl_gpios_desc[i].mctrl));
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_set);
+
+struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
+                                   enum mctrl_gpio_idx gidx)
+{
+     if (!IS_ERR_OR_NULL(gpios) && !IS_ERR_OR_NULL(gpios->gpio[gidx]))
+             return gpios->gpio[gidx];
+     else
+             return NULL;
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_to_gpiod);
+
+unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
+{
+     enum mctrl_gpio_idx i;
+
+     /*
+      * return it unchanged if the structure is not allocated
+      */
+     if (IS_ERR_OR_NULL(gpios))
+             return *mctrl;
+
+     for (i = 0; i < UART_GPIO_MAX; i++) {
+             if (!IS_ERR_OR_NULL(gpios->gpio[i]) &&
+                 !mctrl_gpios_desc[i].dir_out) {

drivers/tty/serial/serial_mctrl_gpio.c line 91

Quoted 10 lines

drivers/tty/serial/serial_mctrl_gpio.c new file +10 -0

+                     if (gpiod_get_value(gpios->gpio[i]))
+                             *mctrl |= mctrl_gpios_desc[i].mctrl;
+                     else
+                             *mctrl &= ~mctrl_gpios_desc[i].mctrl;
+             }
+     }
+
+     return *mctrl;
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_get);

Should this routine be renamed to msr_gpio_get() or perhaps better to give all values (inputs and outputs)?

I'm trying to port this approach to omap-serial to implement RS485 switching. I need to know if RTS is already on or not and set it accordingly.

What would be the best solution for this task using this new API?

2014-04-22 15:08 GMT+02:00 Yegor Yefremov <[email protected]>:

Quoted 81 lines · Richard Genoud

Quoted 6 lines

This patch add some helpers to control modem lines (CTS/RTS/DSR...) via GPIO.
This will be useful for many boards which have a serial controller that only handle CTS/RTS pins (or even just RX/TX).

Signed-off-by Richard Genoud <[email protected]>

....

Quoted 58 lines

drivers/tty/serial/serial_mctrl_gpio.c new file +58 -0

+
+struct mctrl_gpios {
+     struct gpio_desc *gpio[UART_GPIO_MAX];
+};
+
+static const struct {
+     const char *name;
+     unsigned int mctrl;
+     bool dir_out;
+} mctrl_gpios_desc[UART_GPIO_MAX] = {
+     { "cts", TIOCM_CTS, false, },
+     { "dsr", TIOCM_DSR, false, },
+     { "dcd", TIOCM_CD, false, },
+     { "rng", TIOCM_RNG, false, },
+     { "rts", TIOCM_RTS, true, },
+     { "dtr", TIOCM_DTR, true, },
+     { "out1", TIOCM_OUT1, true, },
+     { "out2", TIOCM_OUT2, true, },
+};
+
+void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
+{
+     enum mctrl_gpio_idx i;
+
+     if (IS_ERR_OR_NULL(gpios))
+             return;
+
+     for (i = 0; i < UART_GPIO_MAX; i++)
+             if (!IS_ERR_OR_NULL(gpios->gpio[i]) &&
+                 mctrl_gpios_desc[i].dir_out)
+                     gpiod_set_value(gpios->gpio[i],
+                                     !!(mctrl & mctrl_gpios_desc[i].mctrl));
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_set);
+
+struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
+                                   enum mctrl_gpio_idx gidx)
+{
+     if (!IS_ERR_OR_NULL(gpios) && !IS_ERR_OR_NULL(gpios->gpio[gidx]))
+             return gpios->gpio[gidx];
+     else
+             return NULL;
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_to_gpiod);
+
+unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
+{
+     enum mctrl_gpio_idx i;
+
+     /*
+      * return it unchanged if the structure is not allocated
+      */
+     if (IS_ERR_OR_NULL(gpios))
+             return *mctrl;
+
+     for (i = 0; i < UART_GPIO_MAX; i++) {
+             if (!IS_ERR_OR_NULL(gpios->gpio[i]) &&
+                 !mctrl_gpios_desc[i].dir_out) {

drivers/tty/serial/serial_mctrl_gpio.c line 91

Quoted 10 lines

drivers/tty/serial/serial_mctrl_gpio.c new file +10 -0

+                     if (gpiod_get_value(gpios->gpio[i]))
+                             *mctrl |= mctrl_gpios_desc[i].mctrl;
+                     else
+                             *mctrl &= ~mctrl_gpios_desc[i].mctrl;
+             }
+     }
+
+     return *mctrl;
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_get);

Should this routine be renamed to msr_gpio_get() or perhaps better to give all values (inputs and outputs)?

Quoted 3 lines

I'm trying to port this approach to omap-serial to implement RS485 switching. I need to know if RTS is already on or not and set it accordingly.

What would be the best solution for this task using this new API?

Sorry, but I don't really get what you're trying to do. Could you explain a little bit more ?

On sam9x5, dedicated CTS (and RTS) pins are unusable together with the LCDC, the EMAC, or the MMC because they share the same line.

Moreover, the USART controller doesn't handle DTR/DSR/DCD/RI signals, so we have to control them via GPIO.

This patch permits to use GPIOs to control the CTS/RTS/DTR/DSR/DCD/RI signals.

Signed-off-by Richard Genoud <[email protected]>

---
 .../devicetree/bindings/serial/atmel-usart.txt     |  12 ++-
 arch/arm/mach-at91/at91rm9200_devices.c            |  16 ++--
 arch/arm/mach-at91/at91sam9260_devices.c           |   7 --
 arch/arm/mach-at91/at91sam9261_devices.c           |   4 -
 arch/arm/mach-at91/at91sam9263_devices.c           |   4 -
 arch/arm/mach-at91/at91sam9g45_devices.c           |   5 -
 arch/arm/mach-at91/at91sam9rl_devices.c            |   5 -
 drivers/tty/serial/Kconfig                         |   1 +
 drivers/tty/serial/atmel_serial.c                  | 105 ++++++++++++++-------
 include/linux/platform_data/atmel.h                |   1 -
 10 files changed, 90 insertions(+), 70 deletions(-)

Documentation/devicetree/bindings/serial/atmel-usart.txt +9 -3

index 17c1042b2df8..a6391e70a8fd 100644
@@ -13,8 +13,9 @@ Required properties:
 Optional properties:
 - atmel,use-dma-rx: use of PDC or DMA for receiving data
 - atmel,use-dma-tx: use of PDC or DMA for transmitting data
-- rts-gpios: specify a GPIO for RTS line. It will use specified PIO instead of the peripheral
-  function pin for the USART RTS feature. If unsure, don't specify this property.
+- {rts,cts,dtr,dsr,rng,dcd}-gpios: specify a GPIO for RTS/CTS/DTR/DSR/RI/DCD line respectively.
+  It will use specified PIO instead of the peripheral function pin for the USART feature.
+  If unsure, don't specify this property.
 - add dma bindings for dma transfer:
 	- dmas: DMA specifier, consisting of a phandle to DMA controller node,
 		memory peripheral interface and USART DMA channel ID, FIFO configuration.

@@ -35,7 +36,12 @@ Example:
 		clock-names = "usart";
 		atmel,use-dma-rx;
 		atmel,use-dma-tx;
-		rts-gpios = <&pioD 15 0>;
+		rts-gpios = <&pioD 15 GPIO_ACTIVE_LOW>;
+		cts-gpios = <&pioD 16 GPIO_ACTIVE_LOW>;
+		dtr-gpios = <&pioD 17 GPIO_ACTIVE_LOW>;
+		dsr-gpios = <&pioD 18 GPIO_ACTIVE_LOW>;
+		dcd-gpios = <&pioD 20 GPIO_ACTIVE_LOW>;
+		rng-gpios = <&pioD 19 GPIO_ACTIVE_LOW>;
 	};
 
 - use DMA:

arch/arm/mach-at91/at91rm9200_devices.c +10 -6

index f3f19f21352a..291a90a5b1d4 100644
@@ -15,6 +15,7 @@
 
 #include <linux/dma-mapping.h>
 #include <linux/gpio.h>
+#include <linux/gpio/driver.h>
 #include <linux/platform_device.h>
 #include <linux/i2c-gpio.h>
 

@@ -923,7 +924,6 @@ static struct resource dbgu_resources[] = {
 static struct atmel_uart_data dbgu_data = {
 	.use_dma_tx	= 0,
 	.use_dma_rx	= 0,		/* DBGU not capable of receive DMA */
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);

@@ -962,7 +962,14 @@ static struct resource uart0_resources[] = {
 static struct atmel_uart_data uart0_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
+};
+
+static struct gpiod_lookup_table uart0_gpios_table = {
+	.dev_id = "atmel_usart",
+	.table = {
+		GPIO_LOOKUP("pioA", 21, "rts", GPIO_ACTIVE_LOW),
+		{ },
+	},
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);

@@ -993,7 +1000,7 @@ static inline void configure_usart0_pins(unsigned pins)
 		 * We need to drive the pin manually. The serial driver will driver
 		 * this to high when initializing.
 		 */
-		uart0_data.rts_gpio = AT91_PIN_PA21;
+		gpiod_add_lookup_table(&uart0_gpios_table);
 	}
 }
 

@@ -1013,7 +1020,6 @@ static struct resource uart1_resources[] = {
 static struct atmel_uart_data uart1_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);

@@ -1065,7 +1071,6 @@ static struct resource uart2_resources[] = {
 static struct atmel_uart_data uart2_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);

@@ -1109,7 +1114,6 @@ static struct resource uart3_resources[] = {
 static struct atmel_uart_data uart3_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart3_dmamask = DMA_BIT_MASK(32);

arch/arm/mach-at91/at91sam9260_devices.c +0 -7

index 2ae7715f1309..a1b989eac8b8 100644
@@ -820,7 +820,6 @@ static struct resource dbgu_resources[] = {
 static struct atmel_uart_data dbgu_data = {
 	.use_dma_tx	= 0,
 	.use_dma_rx	= 0,		/* DBGU not capable of receive DMA */
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);

@@ -859,7 +858,6 @@ static struct resource uart0_resources[] = {
 static struct atmel_uart_data uart0_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);

@@ -911,7 +909,6 @@ static struct resource uart1_resources[] = {
 static struct atmel_uart_data uart1_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);

@@ -955,7 +952,6 @@ static struct resource uart2_resources[] = {
 static struct atmel_uart_data uart2_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);

@@ -999,7 +995,6 @@ static struct resource uart3_resources[] = {
 static struct atmel_uart_data uart3_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart3_dmamask = DMA_BIT_MASK(32);

@@ -1043,7 +1038,6 @@ static struct resource uart4_resources[] = {
 static struct atmel_uart_data uart4_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart4_dmamask = DMA_BIT_MASK(32);

@@ -1082,7 +1076,6 @@ static struct resource uart5_resources[] = {
 static struct atmel_uart_data uart5_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart5_dmamask = DMA_BIT_MASK(32);

arch/arm/mach-at91/at91sam9261_devices.c +0 -4

index 80e35895d28f..b5f7a7226ff8 100644
@@ -881,7 +881,6 @@ static struct resource dbgu_resources[] = {
 static struct atmel_uart_data dbgu_data = {
 	.use_dma_tx	= 0,
 	.use_dma_rx	= 0,		/* DBGU not capable of receive DMA */
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);

@@ -920,7 +919,6 @@ static struct resource uart0_resources[] = {
 static struct atmel_uart_data uart0_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);

@@ -964,7 +962,6 @@ static struct resource uart1_resources[] = {
 static struct atmel_uart_data uart1_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);

@@ -1008,7 +1005,6 @@ static struct resource uart2_resources[] = {
 static struct atmel_uart_data uart2_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);

arch/arm/mach-at91/at91sam9263_devices.c +0 -4

index 43d53d6156dd..39803c3296b2 100644
@@ -1325,7 +1325,6 @@ static struct resource dbgu_resources[] = {
 static struct atmel_uart_data dbgu_data = {
 	.use_dma_tx	= 0,
 	.use_dma_rx	= 0,		/* DBGU not capable of receive DMA */
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);

@@ -1364,7 +1363,6 @@ static struct resource uart0_resources[] = {
 static struct atmel_uart_data uart0_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);

@@ -1408,7 +1406,6 @@ static struct resource uart1_resources[] = {
 static struct atmel_uart_data uart1_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);

@@ -1452,7 +1449,6 @@ static struct resource uart2_resources[] = {
 static struct atmel_uart_data uart2_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);

arch/arm/mach-at91/at91sam9g45_devices.c +0 -5

index 77b04c2edd78..4e53d8d9737b 100644
@@ -1588,7 +1588,6 @@ static struct resource dbgu_resources[] = {
 static struct atmel_uart_data dbgu_data = {
 	.use_dma_tx	= 0,
 	.use_dma_rx	= 0,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);

@@ -1627,7 +1626,6 @@ static struct resource uart0_resources[] = {
 static struct atmel_uart_data uart0_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);

@@ -1671,7 +1669,6 @@ static struct resource uart1_resources[] = {
 static struct atmel_uart_data uart1_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);

@@ -1715,7 +1712,6 @@ static struct resource uart2_resources[] = {
 static struct atmel_uart_data uart2_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);

@@ -1759,7 +1755,6 @@ static struct resource uart3_resources[] = {
 static struct atmel_uart_data uart3_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart3_dmamask = DMA_BIT_MASK(32);

arch/arm/mach-at91/at91sam9rl_devices.c +0 -5

index 428fc412aaf1..f75985062913 100644
@@ -957,7 +957,6 @@ static struct resource dbgu_resources[] = {
 static struct atmel_uart_data dbgu_data = {
 	.use_dma_tx	= 0,
 	.use_dma_rx	= 0,		/* DBGU not capable of receive DMA */
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);

@@ -996,7 +995,6 @@ static struct resource uart0_resources[] = {
 static struct atmel_uart_data uart0_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);

@@ -1048,7 +1046,6 @@ static struct resource uart1_resources[] = {
 static struct atmel_uart_data uart1_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);

@@ -1092,7 +1089,6 @@ static struct resource uart2_resources[] = {
 static struct atmel_uart_data uart2_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);

@@ -1136,7 +1132,6 @@ static struct resource uart3_resources[] = {
 static struct atmel_uart_data uart3_data = {
 	.use_dma_tx	= 1,
 	.use_dma_rx	= 1,
-	.rts_gpio	= -EINVAL,
 };
 
 static u64 uart3_dmamask = DMA_BIT_MASK(32);

drivers/tty/serial/Kconfig +1 -0

index 7e8f15cfb8d0..f4e20410a138 100644
@@ -97,6 +97,7 @@ config SERIAL_ATMEL
 	bool "AT91 / AT32 on-chip serial port support"
 	depends on ARCH_AT91 || AVR32
 	select SERIAL_CORE
+	select SERIAL_MCTRL_GPIO
 	help
 	  This enables the driver for the on-chip UARTs of the Atmel
 	  AT91 and AT32 processors.

drivers/tty/serial/atmel_serial.c +70 -35

index 53eeea13ff16..43ca659c1d4b 100644
@@ -43,6 +43,8 @@
 #include <linux/platform_data/atmel.h>
 #include <linux/timer.h>
 #include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/err.h>
 
 #include <asm/io.h>
 #include <asm/ioctls.h>

@@ -57,6 +59,8 @@
 
 #include <linux/serial_core.h>
 
+#include "serial_mctrl_gpio.h"
+
 static void atmel_start_rx(struct uart_port *port);
 static void atmel_stop_rx(struct uart_port *port);
 

@@ -162,7 +166,7 @@ struct atmel_uart_port {
 	struct circ_buf		rx_ring;
 
 	struct serial_rs485	rs485;		/* rs485 settings */
-	int			rts_gpio;	/* optional RTS GPIO */
+	struct mctrl_gpios	*gpios;
 	unsigned int		tx_done_mask;
 	bool			is_usart;	/* usart or uart */
 	struct timer_list	uart_timer;	/* uart timer */

@@ -237,6 +241,50 @@ static bool atmel_use_dma_rx(struct uart_port *port)
 	return atmel_port->use_dma_rx;
 }
 
+static unsigned int atmel_get_lines_status(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	unsigned int status, ret = 0;
+
+	status = UART_GET_CSR(port);
+
+	mctrl_gpio_get(atmel_port->gpios, &ret);
+
+	if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios,
+						UART_GPIO_CTS))) {
+		if (ret & TIOCM_CTS)
+			status &= ~ATMEL_US_CTS;
+		else
+			status |= ATMEL_US_CTS;
+	}
+
+	if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios,
+						UART_GPIO_DSR))) {
+		if (ret & TIOCM_DSR)
+			status &= ~ATMEL_US_DSR;
+		else
+			status |= ATMEL_US_DSR;
+	}
+
+	if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios,
+						UART_GPIO_RI))) {
+		if (ret & TIOCM_RI)
+			status &= ~ATMEL_US_RI;
+		else
+			status |= ATMEL_US_RI;
+	}
+
+	if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios,
+						UART_GPIO_DCD))) {
+		if (ret & TIOCM_CD)
+			status &= ~ATMEL_US_DCD;
+		else
+			status |= ATMEL_US_DCD;
+	}
+
+	return status;
+}
+
 /* Enable or disable the rs485 support */
 void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
 {

@@ -296,17 +344,6 @@ 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);
 
-	/*
-	 * AT91RM9200 Errata #39: RTS0 is not internally connected
-	 * to PA21. We need to drive the pin as a GPIO.
-	 */
-	if (gpio_is_valid(atmel_port->rts_gpio)) {
-		if (mctrl & TIOCM_RTS)
-			gpio_set_value(atmel_port->rts_gpio, 0);
-		else
-			gpio_set_value(atmel_port->rts_gpio, 1);
-	}
-
 	if (mctrl & TIOCM_RTS)
 		control |= ATMEL_US_RTSEN;
 	else

@@ -319,6 +356,8 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
 
 	UART_PUT_CR(port, control);
 
+	mctrl_gpio_set(atmel_port->gpios, mctrl);
+
 	/* Local loopback mode? */
 	mode = UART_GET_MR(port) & ~ATMEL_US_CHMODE;
 	if (mctrl & TIOCM_LOOP)

@@ -346,7 +385,8 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
  */
 static u_int atmel_get_mctrl(struct uart_port *port)
 {
-	unsigned int status, ret = 0;
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	unsigned int ret = 0, status;
 
 	status = UART_GET_CSR(port);
 

@@ -362,7 +402,7 @@ static u_int atmel_get_mctrl(struct uart_port *port)
 	if (!(status & ATMEL_US_RI))
 		ret |= TIOCM_RI;
 
-	return ret;
+	return mctrl_gpio_get(atmel_port->gpios, &ret);
 }
 
 /*

@@ -1042,7 +1082,7 @@ static irqreturn_t atmel_interrupt(int irq, void *dev_id)
 	unsigned int status, pending, pass_counter = 0;
 
 	do {
-		status = UART_GET_CSR(port);
+		status = atmel_get_lines_status(port);
 		pending = status & UART_GET_IMR(port);
 		if (!pending)
 			break;

@@ -1568,7 +1608,7 @@ static int atmel_startup(struct uart_port *port)
 	}
 
 	/* Save current CSR for comparison in atmel_tasklet_func() */
-	atmel_port->irq_status_prev = UART_GET_CSR(port);
+	atmel_port->irq_status_prev = atmel_get_lines_status(port);
 	atmel_port->irq_status = atmel_port->irq_status_prev;
 
 	/*

@@ -2324,6 +2364,15 @@ static int atmel_serial_resume(struct platform_device *pdev)
 #define atmel_serial_resume NULL
 #endif
 
+static int atmel_init_gpios(struct atmel_uart_port *p, struct device *dev)
+{
+	p->gpios = mctrl_gpio_init(dev, 0);
+	if (IS_ERR_OR_NULL(p->gpios))
+		return -1;
+
+	return 0;
+}
+
 static int atmel_serial_probe(struct platform_device *pdev)
 {
 	struct atmel_uart_port *port;

@@ -2359,25 +2408,11 @@ static int atmel_serial_probe(struct platform_device *pdev)
 	port = &atmel_ports[ret];
 	port->backup_imr = 0;
 	port->uart.line = ret;
-	port->rts_gpio = -EINVAL; /* Invalid, zero could be valid */
-	if (pdata)
-		port->rts_gpio = pdata->rts_gpio;
-	else if (np)
-		port->rts_gpio = of_get_named_gpio(np, "rts-gpios", 0);
-
-	if (gpio_is_valid(port->rts_gpio)) {
-		ret = devm_gpio_request(&pdev->dev, port->rts_gpio, "RTS");
-		if (ret) {
-			dev_err(&pdev->dev, "error requesting RTS GPIO\n");
-			goto err;
-		}
-		/* Default to 1 as RTS is active low */
-		ret = gpio_direction_output(port->rts_gpio, 1);
-		if (ret) {
-			dev_err(&pdev->dev, "error setting up RTS GPIO\n");
-			goto err;
-		}
-	}
+
+	ret = atmel_init_gpios(port, &pdev->dev);
+	if (ret < 0)
+		dev_err(&pdev->dev, "%s",
+			"Failed to initialize GPIOs. The serial port may not work as expected");
 
 	ret = atmel_init_port(port, pdev);
 	if (ret)

include/linux/platform_data/atmel.h +0 -1

index e26b0c14edea..cea9f70133c5 100644
@@ -84,7 +84,6 @@ 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 */
-	int			rts_gpio;	/* optional RTS GPIO */
 };
 
  /* Touchscreen Controller */

Handle CTS/DSR/RI/DCD GPIO interrupts in atmel_serial.

Signed-off-by Richard Genoud <[email protected]>

---
 drivers/tty/serial/atmel_serial.c | 125 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 122 insertions(+), 3 deletions(-)

drivers/tty/serial/atmel_serial.c +122 -3

index 43ca659c1d4b..3fceae099c44 100644
@@ -45,6 +45,7 @@
 #include <linux/gpio.h>
 #include <linux/gpio/consumer.h>
 #include <linux/err.h>
+#include <linux/irq.h>
 
 #include <asm/io.h>
 #include <asm/ioctls.h>

@@ -167,7 +168,9 @@ struct atmel_uart_port {
 
 	struct serial_rs485	rs485;		/* rs485 settings */
 	struct mctrl_gpios	*gpios;
+	int			gpio_irq[UART_GPIO_MAX];
 	unsigned int		tx_done_mask;
+	bool			ms_irq_enabled;
 	bool			is_usart;	/* usart or uart */
 	struct timer_list	uart_timer;	/* uart timer */
 	int (*prepare_rx)(struct uart_port *port);

@@ -489,8 +492,38 @@ static void atmel_stop_rx(struct uart_port *port)
  */
 static void atmel_enable_ms(struct uart_port *port)
 {
-	UART_PUT_IER(port, ATMEL_US_RIIC | ATMEL_US_DSRIC
-			| ATMEL_US_DCDIC | ATMEL_US_CTSIC);
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	uint32_t ier = 0;
+
+	/*
+	 * Interrupt should not be enabled twice
+	 */
+	if (atmel_port->ms_irq_enabled)
+		return;
+
+	atmel_port->ms_irq_enabled = true;
+
+	if (atmel_port->gpio_irq[UART_GPIO_CTS] >= 0)
+		enable_irq(atmel_port->gpio_irq[UART_GPIO_CTS]);
+	else
+		ier |= ATMEL_US_CTSIC;
+
+	if (atmel_port->gpio_irq[UART_GPIO_DSR] >= 0)
+		enable_irq(atmel_port->gpio_irq[UART_GPIO_DSR]);
+	else
+		ier |= ATMEL_US_DSRIC;
+
+	if (atmel_port->gpio_irq[UART_GPIO_RI] >= 0)
+		enable_irq(atmel_port->gpio_irq[UART_GPIO_RI]);
+	else
+		ier |= ATMEL_US_RIIC;
+
+	if (atmel_port->gpio_irq[UART_GPIO_DCD] >= 0)
+		enable_irq(atmel_port->gpio_irq[UART_GPIO_DCD]);
+	else
+		ier |= ATMEL_US_DCDIC;
+
+	UART_PUT_IER(port, ier);
 }
 
 /*

@@ -1079,11 +1112,31 @@ atmel_handle_status(struct uart_port *port, unsigned int pending,
 static irqreturn_t atmel_interrupt(int irq, void *dev_id)
 {
 	struct uart_port *port = dev_id;
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
 	unsigned int status, pending, pass_counter = 0;
+	bool gpio_handled = false;
 
 	do {
 		status = atmel_get_lines_status(port);
 		pending = status & UART_GET_IMR(port);
+		if (!gpio_handled) {
+			/*
+			 * Dealing with GPIO interrupt
+			 */
+			if (irq == atmel_port->gpio_irq[UART_GPIO_CTS])
+				pending |= ATMEL_US_CTSIC;
+
+			if (irq == atmel_port->gpio_irq[UART_GPIO_DSR])
+				pending |= ATMEL_US_DSRIC;
+
+			if (irq == atmel_port->gpio_irq[UART_GPIO_RI])
+				pending |= ATMEL_US_RIIC;
+
+			if (irq == atmel_port->gpio_irq[UART_GPIO_DCD])
+				pending |= ATMEL_US_DCDIC;
+
+			gpio_handled = true;
+		}
 		if (!pending)
 			break;
 

@@ -1563,6 +1616,45 @@ static void atmel_get_ip_name(struct uart_port *port)
 	}
 }
 
+static void atmel_free_gpio_irq(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	enum mctrl_gpio_idx i;
+
+	for (i = 0; i < UART_GPIO_MAX; i++)
+		if (atmel_port->gpio_irq[i] >= 0)
+			free_irq(atmel_port->gpio_irq[i], port);
+}
+
+static int atmel_request_gpio_irq(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	int *irq = atmel_port->gpio_irq;
+	enum mctrl_gpio_idx i;
+	int err = 0;
+
+	for (i = 0; (i < UART_GPIO_MAX) && !err; i++) {
+		if (irq[i] < 0)
+			continue;
+
+		irq_set_status_flags(irq[i], IRQ_NOAUTOEN);
+		err = request_irq(irq[i], atmel_interrupt, IRQ_TYPE_EDGE_BOTH,
+				  "atmel_serial", port);
+		if (err)
+			dev_err(port->dev, "atmel_startup - Can't get %d irq\n",
+				irq[i]);
+	}
+
+	/*
+	 * If something went wrong, rollback.
+	 */
+	while (err && (--i >= 0))
+		if (irq[i] >= 0)
+			free_irq(irq[i], port);
+
+	return err;
+}
+
 /*
  * Perform initialization and enable port for reception
  */

@@ -1579,6 +1671,7 @@ static int atmel_startup(struct uart_port *port)
 	 * handle an unexpected interrupt
 	 */
 	UART_PUT_IDR(port, -1);
+	atmel_port->ms_irq_enabled = false;
 
 	/*
 	 * Allocate the IRQ

@@ -1591,6 +1684,13 @@ static int atmel_startup(struct uart_port *port)
 	}
 
 	/*
+	 * Get the GPIO lines IRQ
+	 */
+	retval = atmel_request_gpio_irq(port);
+	if (retval)
+		goto free_irq;
+
+	/*
 	 * Initialize DMA (if necessary)
 	 */
 	atmel_init_property(atmel_port, pdev);

@@ -1654,6 +1754,11 @@ static int atmel_startup(struct uart_port *port)
 	}
 
 	return 0;
+
+free_irq:
+	free_irq(port->irq, port);
+
+	return retval;
 }
 
 /*

@@ -1701,9 +1806,12 @@ static void atmel_shutdown(struct uart_port *port)
 	atmel_port->rx_ring.tail = 0;
 
 	/*
-	 * Free the interrupt
+	 * Free the interrupts
 	 */
 	free_irq(port->irq, port);
+	atmel_free_gpio_irq(port);
+
+	atmel_port->ms_irq_enabled = false;
 }
 
 /*

@@ -2366,10 +2474,21 @@ static int atmel_serial_resume(struct platform_device *pdev)
 
 static int atmel_init_gpios(struct atmel_uart_port *p, struct device *dev)
 {
+	enum mctrl_gpio_idx i;
+	struct gpio_desc *gpiod;
+
 	p->gpios = mctrl_gpio_init(dev, 0);
 	if (IS_ERR_OR_NULL(p->gpios))
 		return -1;
 
+	for (i = 0; i < UART_GPIO_MAX; i++) {
+		gpiod = mctrl_gpio_to_gpiod(p->gpios, i);
+		if (gpiod && (gpiod_get_direction(gpiod) == GPIOF_DIR_IN))
+			p->gpio_irq[i] = gpiod_to_irq(gpiod);
+		else
+			p->gpio_irq[i] = -EINVAL;
+	}
+
 	return 0;
 }