[PATCH v4 0/5] tty/serial: Add helpers to use GPIOs to control modem lines and implement atmel_serial.c

[PATCH v4 0/5] tty/serial: Add helpers to use GPIOs to control modem lines and implement atmel_serial.c

[Richard Genoud]

The USART controller on sam9x5 chips (and also all AT91/SAMA5 chips
but at91rm9200) are not capable of handling DTR/DSR/DCD/RI signal.
Moreover, even if the controller can handle CTS/RTS, the dedicated
CTS/RTS pins are already muxed for other peripherals (LCDC/EMAC/MMC).

So this patchset adds the possibility to control those lines via GPIO,
as it is done for RTS in the patch "switch atmel serial to use gpiolib"

As it was suggested by Alexander Shiyan, I made that available for
every board.

Patch 1 implements the generic helpers to control modem lines via GPIO
Patches 2 and 3 are just a little tidy up of atmel_serial.c.
Patch 4 implements modem control lines in atmel_serial atmel_serial.
Patch 5 implement the interrupts of CTS/DSR/DCD/RI.

This is based on next-20140226 + [PATCH v3 5/7] ARM: at91: gpio: implement get_direction
That Nicolas (has/will/might) appl(ied/y) on AT91 tree.

Tested on at91sam9g35, with a null modem cable between 2 serial ports,
one with CTS/RTS controlled by the USART controller, the other via GPIO,
full duplex transfers.
Did some tests also with null modem cables on a PC, and with real modems.

Updates from v3:
	- add static keyword on struct uart0_gpios_table.
	- add use an index at the mctrl_gpio_init() function to make it
	usable by driver that allocates several ports at once.
	- hide struct gpio_desc from users.
	- patch "pinctrl: at91: implement get_direction" has been picked by Linus.
	- patch "ARM: at91: gpio: implement get_direction" has been acked by Linus.

Updates from v2:
	- remove UART_GPIO_MIN/UART_GPIO_MAX_INPUT and use a direction
	boolean instead.
	- implement get_direction in at91 pinctrl and mach-at91/gpio.c.
	- remove the get_mctrl_gpio_name() function that was used for
	logs only.
	- split atmel_serial.c patch in 2.
	- use a gpio lookup table to declare modem gpios in platform
	devices boards. So there's no more special case for platform
	data gpios in atmel_serial.c.

Updates from v1:
	- Instead of controlling modem signal only on atmel board, the
	code is now available for every board.
	- The active low flag from device tree is now used.

Richard Genoud (5):
  tty/serial: Add GPIOLIB helpers for controlling modem lines
  tty/serial: at91: use dev_err instead of printk
  tty/serial: at91: remove unused open/close hooks
  tty/serial: at91: use mctrl_gpio helpers
  tty/serial: at91: add interrupts for modem control lines

 Documentation/serial/driver              |  25 +++
 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               |   4 +
 drivers/tty/serial/Makefile              |   3 +
 drivers/tty/serial/atmel_serial.c        | 259 ++++++++++++++++++++++++-------
 drivers/tty/serial/serial_mctrl_gpio.c   | 146 +++++++++++++++++
 drivers/tty/serial/serial_mctrl_gpio.h   | 109 +++++++++++++
 include/linux/platform_data/atmel.h      |   1 -
 13 files changed, 496 insertions(+), 92 deletions(-)
 create mode 100644 drivers/tty/serial/serial_mctrl_gpio.c
 create mode 100644 drivers/tty/serial/serial_mctrl_gpio.h

-- 
1.8.5

[PATCH v4 1/5] tty/serial: Add GPIOLIB helpers for controlling modem 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 <richard.genoud@gmail.com>
---
 Documentation/serial/driver            |  25 ++++++
 drivers/tty/serial/Kconfig             |   3 +
 drivers/tty/serial/Makefile            |   3 +
 drivers/tty/serial/serial_mctrl_gpio.c | 146 +++++++++++++++++++++++++++++++++
 drivers/tty/serial/serial_mctrl_gpio.h | 109 ++++++++++++++++++++++++
 5 files changed, 286 insertions(+)
 create mode 100644 drivers/tty/serial/serial_mctrl_gpio.c
 create mode 100644 drivers/tty/serial/serial_mctrl_gpio.h

diff --git a/Documentation/serial/driver b/Documentation/serial/driver
index c3a7689a90e6..3bba1aeb799c 100644
--- a/Documentation/serial/driver
+++ b/Documentation/serial/driver
@@ -429,3 +429,28 @@ thus:
 		struct uart_port	port;
 		int			my_stuff;
 	};
+
+Modem control lines via GPIO
+----------------------------
+
+Some helpers are provided in order to set/get modem control lines via GPIO.
+
+mctrl_gpio_init(dev, idx):
+	This will get the {cts,rts,...}-gpios from device tree if they are
+	present and request them, set direction etc, and return an
+	allocated structure. devm_* functions are used, so there's no need
+	to call mctrl_gpio_free().
+
+mctrl_gpio_free(dev, gpios):
+	This will free the requested gpios in mctrl_gpio_init().
+	As devm_* function are used, there's generally no need to call
+	this function.
+
+mctrl_gpio_to_gpiod(gpios, gidx)
+	This returns the gpio structure associated to the modem line index.
+
+mctrl_gpio_set(gpios, mctrl):
+	This will sets the gpios according to the mctrl state.
+
+mctrl_gpio_get(gpios, mctrl):
+	This will update mctrl with the gpios values.
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 2e6d8ddc4425..7e8f15cfb8d0 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1509,4 +1509,7 @@ config SERIAL_ST_ASC_CONSOLE
 
 endmenu
 
+config SERIAL_MCTRL_GPIO
+	tristate
+
 endif # TTY
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index 3680854fef41..bcf31da267dd 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -87,3 +87,6 @@ obj-$(CONFIG_SERIAL_EFM32_UART) += efm32-uart.o
 obj-$(CONFIG_SERIAL_ARC)	+= arc_uart.o
 obj-$(CONFIG_SERIAL_RP2)	+= rp2.o
 obj-$(CONFIG_SERIAL_FSL_LPUART)	+= fsl_lpuart.o
+
+# GPIOLIB helpers for modem control lines
+obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
diff --git a/drivers/tty/serial/serial_mctrl_gpio.c b/drivers/tty/serial/serial_mctrl_gpio.c
new file mode 100644
index 000000000000..344641f31304
--- /dev/null
+++ b/drivers/tty/serial/serial_mctrl_gpio.c
@@ -0,0 +1,146 @@
+/*
+ * Helpers for controlling modem lines via GPIO
+ *
+ * Copyright (C) 2014 Paratronic S.A.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <uapi/asm-generic/termios.h>
+
+#include "serial_mctrl_gpio.h"
+
+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, },
+	{ "ri", TIOCM_RI, 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) {
+			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);
+
+struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx)
+{
+	struct mctrl_gpios *gpios;
+	enum mctrl_gpio_idx i;
+	int err;
+
+	gpios = devm_kzalloc(dev, sizeof(*gpios), GFP_KERNEL);
+	if (IS_ERR_OR_NULL(gpios))
+		goto out;
+
+	for (i = 0; i < UART_GPIO_MAX; i++) {
+		gpios->gpio[i] = devm_gpiod_get_index(dev,
+						      mctrl_gpios_desc[i].name,
+						      idx);
+
+		/*
+		 * The GPIOs are maybe not all filled,
+		 * this is not an error.
+		 */
+		if (IS_ERR_OR_NULL(gpios->gpio[i]))
+			continue;
+
+		if (mctrl_gpios_desc[i].dir_out)
+			err = gpiod_direction_output(gpios->gpio[i], 0);
+		else
+			err = gpiod_direction_input(gpios->gpio[i]);
+		if (err) {
+			dev_err(dev, "Unable to set direction for %s GPIO",
+				mctrl_gpios_desc[i].name);
+			devm_gpiod_put(dev, gpios->gpio[i]);
+			gpios->gpio[i] = NULL;
+		}
+	}
+
+out:
+	return gpios;
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_init);
+
+void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
+{
+	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])) {
+			devm_gpiod_put(dev, gpios->gpio[i]);
+			gpios->gpio[i] = NULL;
+		}
+	devm_kfree(dev, gpios);
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_free);
diff --git a/drivers/tty/serial/serial_mctrl_gpio.h b/drivers/tty/serial/serial_mctrl_gpio.h
new file mode 100644
index 000000000000..4ed2f814028b
--- /dev/null
+++ b/drivers/tty/serial/serial_mctrl_gpio.h
@@ -0,0 +1,109 @@
+/*
+ * Helpers for controlling modem lines via GPIO
+ *
+ * Copyright (C) 2014 Paratronic S.A.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef __SERIAL_MCTRL_GPIO__
+#define __SERIAL_MCTRL_GPIO__
+
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+
+enum mctrl_gpio_idx {
+	UART_GPIO_CTS,
+	UART_GPIO_DSR,
+	UART_GPIO_DCD,
+	UART_GPIO_RI,
+	UART_GPIO_RTS,
+	UART_GPIO_DTR,
+	UART_GPIO_OUT1,
+	UART_GPIO_OUT2,
+	UART_GPIO_MAX,
+};
+
+/*
+ * Opaque descriptor for modem lines controlled by GPIOs
+ */
+struct mctrl_gpios;
+
+#ifdef CONFIG_GPIOLIB
+
+/*
+ * Set state of the modem control output lines via GPIOs.
+ */
+void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl);
+
+/*
+ * Get state of the modem control output lines from GPIOs.
+ * The mctrl flags are updated and returned.
+ */
+unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl);
+
+/*
+ * Returns the associated struct gpio_desc to the modem line gidx
+ */
+struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
+				      enum mctrl_gpio_idx gidx);
+
+/*
+ * Request and set direction of modem control lines GPIOs.
+ * devm_* functions are used, so there's no need to call mctrl_gpio_free().
+ * Returns a pointer to the allocated mctrl structure if ok,
+ * or an error from devm_kzalloc().
+ */
+struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx);
+
+/*
+ * Free the mctrl_gpios structure.
+ * Normally, this function will not be called, as the GPIOs will
+ * be disposed of by the resource management code.
+ */
+void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios);
+
+#else /* GPIOLIB */
+
+static inline
+void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
+{
+}
+
+static inline
+unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
+{
+	return *mctrl;
+}
+
+static inline
+struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
+				      enum mctrl_gpio_idx gidx)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+static inline
+struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+static inline
+void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
+{
+}
+
+#endif /* GPIOLIB */
+
+#endif
-- 
1.8.5

[PATCH v4 2/5] tty/serial: at91: use dev_err instead of printk

[Richard Genoud]

For better consistency.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
---
 drivers/tty/serial/atmel_serial.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 79b5057b37b3..8edf8811d61d 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -1549,7 +1549,7 @@ static int atmel_startup(struct uart_port *port)
 	retval = request_irq(port->irq, atmel_interrupt, IRQF_SHARED,
 			tty ? tty->name : "atmel_serial", port);
 	if (retval) {
-		printk("atmel_serial: atmel_startup - Can't get irq\n");
+		dev_err(port->dev, "atmel_startup - Can't get irq\n");
 		return retval;
 	}
 
@@ -1732,7 +1732,7 @@ static void atmel_serial_pm(struct uart_port *port, unsigned int state,
 		clk_disable_unprepare(atmel_port->clk);
 		break;
 	default:
-		printk(KERN_ERR "atmel_serial: unknown pm %d\n", state);
+		dev_err(port->dev, "atmel_serial: unknown pm %d\n", state);
 	}
 }
 
-- 
1.8.5

[PATCH v4 3/5] tty/serial: at91: remove unused open/close hooks

[Richard Genoud]

commit 95e629b761ce36996d1befe2824d5346b5a220b9 removed the use of board
specific hooks in serial_at91.h, so now, the open/close hook are just
dead code.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
---
 drivers/tty/serial/atmel_serial.c | 21 ---------------------
 1 file changed, 21 deletions(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 8edf8811d61d..53eeea13ff16 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -112,9 +112,6 @@ static void atmel_stop_rx(struct uart_port *port);
 #define UART_PUT_TCR(port,v)	__raw_writel(v, (port)->membase + ATMEL_PDC_TCR)
 #define UART_GET_TCR(port)	__raw_readl((port)->membase + ATMEL_PDC_TCR)
 
-static int (*atmel_open_hook)(struct uart_port *);
-static void (*atmel_close_hook)(struct uart_port *);
-
 struct atmel_dma_buffer {
 	unsigned char	*buf;
 	dma_addr_t	dma_addr;
@@ -1569,17 +1566,6 @@ static int atmel_startup(struct uart_port *port)
 		if (retval < 0)
 			atmel_set_ops(port);
 	}
-	/*
-	 * If there is a specific "open" function (to register
-	 * control line interrupts)
-	 */
-	if (atmel_open_hook) {
-		retval = atmel_open_hook(port);
-		if (retval) {
-			free_irq(port->irq, port);
-			return retval;
-		}
-	}
 
 	/* Save current CSR for comparison in atmel_tasklet_func() */
 	atmel_port->irq_status_prev = UART_GET_CSR(port);
@@ -1678,13 +1664,6 @@ static void atmel_shutdown(struct uart_port *port)
 	 * Free the interrupt
 	 */
 	free_irq(port->irq, port);
-
-	/*
-	 * If there is a specific "close" function (to unregister
-	 * control line interrupts)
-	 */
-	if (atmel_close_hook)
-		atmel_close_hook(port);
 }
 
 /*
-- 
1.8.5

[PATCH v4 4/5] tty/serial: at91: use mctrl_gpio helpers

[Richard Genoud]

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 <richard.genoud@gmail.com>
---
 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        | 107 +++++++++++++++++++++----------
 include/linux/platform_data/atmel.h      |   1 -
 9 files changed, 83 insertions(+), 67 deletions(-)

diff --git a/arch/arm/mach-at91/at91rm9200_devices.c b/arch/arm/mach-at91/at91rm9200_devices.c
index f3f19f21352a..291a90a5b1d4 100644
--- a/arch/arm/mach-at91/at91rm9200_devices.c
+++ b/arch/arm/mach-at91/at91rm9200_devices.c
@@ -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);
diff --git a/arch/arm/mach-at91/at91sam9260_devices.c b/arch/arm/mach-at91/at91sam9260_devices.c
index 2ae7715f1309..a1b989eac8b8 100644
--- a/arch/arm/mach-at91/at91sam9260_devices.c
+++ b/arch/arm/mach-at91/at91sam9260_devices.c
@@ -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);
diff --git a/arch/arm/mach-at91/at91sam9261_devices.c b/arch/arm/mach-at91/at91sam9261_devices.c
index 80e35895d28f..b5f7a7226ff8 100644
--- a/arch/arm/mach-at91/at91sam9261_devices.c
+++ b/arch/arm/mach-at91/at91sam9261_devices.c
@@ -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);
diff --git a/arch/arm/mach-at91/at91sam9263_devices.c b/arch/arm/mach-at91/at91sam9263_devices.c
index 43d53d6156dd..39803c3296b2 100644
--- a/arch/arm/mach-at91/at91sam9263_devices.c
+++ b/arch/arm/mach-at91/at91sam9263_devices.c
@@ -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);
diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c
index 77b04c2edd78..4e53d8d9737b 100644
--- a/arch/arm/mach-at91/at91sam9g45_devices.c
+++ b/arch/arm/mach-at91/at91sam9g45_devices.c
@@ -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);
diff --git a/arch/arm/mach-at91/at91sam9rl_devices.c b/arch/arm/mach-at91/at91sam9rl_devices.c
index 428fc412aaf1..f75985062913 100644
--- a/arch/arm/mach-at91/at91sam9rl_devices.c
+++ b/arch/arm/mach-at91/at91sam9rl_devices.c
@@ -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);
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 7e8f15cfb8d0..f4e20410a138 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -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.
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 53eeea13ff16..d7d873c1a1d0 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -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 +2364,17 @@ 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)
+{
+	int err = 0;
+
+	p->gpios = mctrl_gpio_init(dev, 0);
+	if (IS_ERR_OR_NULL(p->gpios))
+		err = PTR_ERR(p->gpios);
+
+	return err;
+}
+
 static int atmel_serial_probe(struct platform_device *pdev)
 {
 	struct atmel_uart_port *port;
@@ -2359,25 +2410,11 @@ 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)
diff --git a/include/linux/platform_data/atmel.h b/include/linux/platform_data/atmel.h
index e26b0c14edea..cea9f70133c5 100644
--- a/include/linux/platform_data/atmel.h
+++ b/include/linux/platform_data/atmel.h
@@ -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 */
-- 
1.8.5

[PATCH v4 5/5] tty/serial: at91: add interrupts for modem control lines

[Richard Genoud]

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

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
---
 drivers/tty/serial/atmel_serial.c | 129 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 126 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index d7d873c1a1d0..779501db72ff 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -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 +1112,35 @@ 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 >= 0) &&
+			    (irq == atmel_port->gpio_irq[UART_GPIO_CTS]))
+				pending |= ATMEL_US_CTSIC;
+
+			if ((irq >= 0) &&
+			    (irq == atmel_port->gpio_irq[UART_GPIO_DSR]))
+				pending |= ATMEL_US_DSRIC;
+
+			if ((irq >= 0) &&
+			    (irq == atmel_port->gpio_irq[UART_GPIO_RI]))
+				pending |= ATMEL_US_RIIC;
+
+			if ((irq >= 0) &&
+			    (irq == atmel_port->gpio_irq[UART_GPIO_DCD]))
+				pending |= ATMEL_US_DCDIC;
+
+			gpio_handled = true;
+		}
 		if (!pending)
 			break;
 
@@ -1563,6 +1620,45 @@ 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)
+		if (irq[i] >= 0)
+			free_irq(irq[i], port);
+
+	return err;
+}
+
 /*
  * Perform initialization and enable port for reception
  */
@@ -1579,6 +1675,7 @@ 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 +1688,13 @@ 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 +1758,11 @@ static int atmel_startup(struct uart_port *port)
 	}
 
 	return 0;
+
+free_irq:
+	free_irq(port->irq, port);
+
+	return retval;
 }
 
 /*
@@ -1701,9 +1810,12 @@ 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;
 }
 
 /*
@@ -2366,12 +2478,23 @@ 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;
 	int err = 0;
 
 	p->gpios = mctrl_gpio_init(dev, 0);
 	if (IS_ERR_OR_NULL(p->gpios))
 		err = PTR_ERR(p->gpios);
 
+	for (i = 0; i < UART_GPIO_MAX; i++) {
+		gpiod = mctrl_gpio_to_gpiod(p->gpios, i);
+		if (!IS_ERR_OR_NULL(gpiod) &&
+		    (gpiod_get_direction(gpiod) == GPIOF_DIR_IN))
+			p->gpio_irq[i] = gpiod_to_irq(gpiod);
+		else
+			p->gpio_irq[i] = -EINVAL;
+	}
+
 	return err;
 }
 
-- 
1.8.5

Re: [PATCH v4 1/5] tty/serial: Add GPIOLIB helpers for controlling modem lines

[Alexander Shiyan]

Hello Richard.

Среда, 26 февраля 2014, 17:19 +01:00 от Richard Genoud <richard.genoud@gmail.com>:
> 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 <richard.genoud@gmail.com>

Better, but I found few bugs... :)

...
> +Modem control lines via GPIO
> +----------------------------
> +
> +Some helpers are provided in order to set/get modem control lines via GPIO.
> +
> +mctrl_gpio_init(dev, idx):

I think we should indicate variable types used in these functions.

...
> +void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
> +{
> +	enum mctrl_gpio_idx i;
> +
> +	if (IS_ERR_OR_NULL(gpios))
> +		return;

No. IS_ERR_OR_NULL() is not valid here. This is allocated by kzalloc(),
so you should check valid pointer only, ie (!gpios).
Same in other places.


> +		if (err) {
> +			dev_err(dev, "Unable to set direction for %s GPIO",
> +				mctrl_gpios_desc[i].name);
> +			devm_gpiod_put(dev, gpios->gpio[i]);
> +			gpios->gpio[i] = NULL;
> +		}
> +	}

Let's use dev_dbg().

Thanks.
---

Re: [PATCH v4 1/5] tty/serial: Add GPIOLIB helpers for controlling modem lines

[Richard Genoud]

2014-02-26 17:37 GMT+01:00 Alexander Shiyan <shc_work@mail.ru>:
> Hello Richard.
>
> Среда, 26 февраля 2014, 17:19 +01:00 от Richard Genoud <richard.genoud@gmail.com>:
>> 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 <richard.genoud@gmail.com>
>
> Better, but I found few bugs... :)
> ...
>> +Modem control lines via GPIO
>> +----------------------------
>> +
>> +Some helpers are provided in order to set/get modem control lines via GPIO.
>> +
>> +mctrl_gpio_init(dev, idx):
>
> I think we should indicate variable types used in these functions.
In the whole file, the variable type are not indicated. So, for
consistency, I think it's better like that.

 ...
>> +void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
>> +{
>> +     enum mctrl_gpio_idx i;
>> +
>> +     if (IS_ERR_OR_NULL(gpios))
>> +             return;
>
> No. IS_ERR_OR_NULL() is not valid here. This is allocated by kzalloc(),
> so you should check valid pointer only, ie (!gpios).
> Same in other places.
You're right !

>
>> +             if (err) {
>> +                     dev_err(dev, "Unable to set direction for %s GPIO",
>> +                             mctrl_gpios_desc[i].name);
>> +                     devm_gpiod_put(dev, gpios->gpio[i]);
>> +                     gpios->gpio[i] = NULL;
>> +             }
>> +     }
>
> Let's use dev_dbg().
Why dbg ? I agree that _err may be a bit strong, we could use
dev_warn() instead.
But as it really should not happen, I'm a bit reluctant to set it as debug.
Or have you something else in mind ?

> Thanks.
> ---

Thanks for reviewing !
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