[PATCH 1/2] tty: move serial PM state to TTY driver interface

[PATCH 1/2] tty: move serial PM state to TTY driver interface

[Rickard Andersson]

From: Linus Walleij <linus.walleij@linaro.org>

We want to make it possible for TTY drivers to control the
power state of the serial core, so as a first step make the
serial core power states generic and rename them TTY_*
so they can be used across all TTY drivers.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/tty/serial/serial_core.c | 28 ++++++++++++++--------------
 include/linux/serial_core.h      | 14 +-------------
 include/linux/tty_driver.h       | 12 ++++++++++++
 3 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 006c0ba..b2fc8d7 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -60,7 +60,7 @@ static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
 					struct ktermios *old_termios);
 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
 static void uart_change_pm(struct uart_state *state,
-			   enum uart_pm_state pm_state);
+			   enum tty_pm_state pm_state);
 
 static void uart_port_shutdown(struct tty_port *port);
 
@@ -1319,7 +1319,7 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
 		spin_lock_irqsave(&port->lock, flags);
 	} else if (!uart_console(uport)) {
 		spin_unlock_irqrestore(&port->lock, flags);
-		uart_change_pm(state, UART_PM_STATE_OFF);
+		uart_change_pm(state, TTY_PM_STATE_OFF);
 		spin_lock_irqsave(&port->lock, flags);
 	}
 
@@ -1533,7 +1533,7 @@ static int uart_open(struct tty_struct *tty, struct file *filp)
 	 * Make sure the device is in D0 state.
 	 */
 	if (port->count == 1)
-		uart_change_pm(state, UART_PM_STATE_ON);
+		uart_change_pm(state, TTY_PM_STATE_ON);
 
 	/*
 	 * Start up the serial port.
@@ -1574,7 +1574,7 @@ static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
 {
 	struct uart_state *state = drv->state + i;
 	struct tty_port *port = &state->port;
-	enum uart_pm_state pm_state;
+	enum tty_pm_state pm_state;
 	struct uart_port *uport = state->uart_port;
 	char stat_buf[32];
 	unsigned int status;
@@ -1599,12 +1599,12 @@ static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
 	if (capable(CAP_SYS_ADMIN)) {
 		mutex_lock(&port->mutex);
 		pm_state = state->pm_state;
-		if (pm_state != UART_PM_STATE_ON)
-			uart_change_pm(state, UART_PM_STATE_ON);
+		if (pm_state != TTY_PM_STATE_ON)
+			uart_change_pm(state, TTY_PM_STATE_ON);
 		spin_lock_irq(&uport->lock);
 		status = uport->ops->get_mctrl(uport);
 		spin_unlock_irq(&uport->lock);
-		if (pm_state != UART_PM_STATE_ON)
+		if (pm_state != TTY_PM_STATE_ON)
 			uart_change_pm(state, pm_state);
 		mutex_unlock(&port->mutex);
 
@@ -1852,7 +1852,7 @@ EXPORT_SYMBOL_GPL(uart_set_options);
  * Locking: port->mutex has to be held
  */
 static void uart_change_pm(struct uart_state *state,
-			   enum uart_pm_state pm_state)
+			   enum tty_pm_state pm_state)
 {
 	struct uart_port *port = state->uart_port;
 
@@ -1937,7 +1937,7 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
 		console_stop(uport->cons);
 
 	if (console_suspend_enabled || !uart_console(uport))
-		uart_change_pm(state, UART_PM_STATE_OFF);
+		uart_change_pm(state, TTY_PM_STATE_OFF);
 
 	mutex_unlock(&port->mutex);
 
@@ -1982,7 +1982,7 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
 			termios = port->tty->termios;
 
 		if (console_suspend_enabled)
-			uart_change_pm(state, UART_PM_STATE_ON);
+			uart_change_pm(state, TTY_PM_STATE_ON);
 		uport->ops->set_termios(uport, &termios, NULL);
 		if (console_suspend_enabled)
 			console_start(uport->cons);
@@ -1992,7 +1992,7 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
 		const struct uart_ops *ops = uport->ops;
 		int ret;
 
-		uart_change_pm(state, UART_PM_STATE_ON);
+		uart_change_pm(state, TTY_PM_STATE_ON);
 		spin_lock_irq(&uport->lock);
 		ops->set_mctrl(uport, 0);
 		spin_unlock_irq(&uport->lock);
@@ -2092,7 +2092,7 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 		uart_report_port(drv, port);
 
 		/* Power up port for set_mctrl() */
-		uart_change_pm(state, UART_PM_STATE_ON);
+		uart_change_pm(state, TTY_PM_STATE_ON);
 
 		/*
 		 * Ensure that the modem control lines are de-activated.
@@ -2116,7 +2116,7 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 		 * console if we have one.
 		 */
 		if (!uart_console(port))
-			uart_change_pm(state, UART_PM_STATE_OFF);
+			uart_change_pm(state, TTY_PM_STATE_OFF);
 	}
 }
 
@@ -2391,7 +2391,7 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
 	}
 
 	state->uart_port = uport;
-	state->pm_state = UART_PM_STATE_UNDEFINED;
+	state->pm_state = TTY_PM_STATE_UNDEFINED;
 
 	uport->cons = drv->cons;
 	uport->state = state;
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index a83c5f6..75f89a7 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -202,25 +202,13 @@ static inline void serial_port_out(struct uart_port *up, int offset, int value)
 	up->serial_out(up, offset, value);
 }
 
-/**
- * enum uart_pm_state - power states for UARTs
- * @UART_PM_STATE_ON: UART is powered, up and operational
- * @UART_PM_STATE_OFF: UART is powered off
- * @UART_PM_STATE_UNDEFINED: sentinel
- */
-enum uart_pm_state {
-	UART_PM_STATE_ON = 0,
-	UART_PM_STATE_OFF = 3, /* number taken from ACPI */
-	UART_PM_STATE_UNDEFINED,
-};
-
 /*
  * This is the state information which is persistent across opens.
  */
 struct uart_state {
 	struct tty_port		port;
 
-	enum uart_pm_state	pm_state;
+	enum tty_pm_state	pm_state;
 	struct circ_buf		xmit;
 
 	struct uart_port	*uart_port;
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index dd976cf..d150a6f 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -241,6 +241,18 @@ struct tty_struct;
 struct tty_driver;
 struct serial_icounter_struct;
 
+/**
+ * enum tty_pm_state - power states for TTYs
+ * @TTY_PM_STATE_ON: TTY is powered, up and operational
+ * @TTY_PM_STATE_OFF: TTY is powered off
+ * @TTY_PM_STATE_UNDEFINED: sentinel
+ */
+enum tty_pm_state {
+	TTY_PM_STATE_ON = 0,
+	TTY_PM_STATE_OFF = 3, /* number taken from ACPI */
+	TTY_PM_STATE_UNDEFINED,
+};
+
 struct tty_operations {
 	struct tty_struct * (*lookup)(struct tty_driver *driver,
 			struct inode *inode, int idx);
-- 
1.8.0

[PATCH 2/2] TTY: serial, add pm function

[Rickard Andersson]

Add power management function to tty driver interface
and add implementation for serial core.

Signed-off-by: Rickard Andersson <rickard.andersson@stericsson.com>
---
 drivers/tty/serial/serial_core.c | 10 ++++++++++
 include/linux/tty_driver.h       |  8 ++++++++
 2 files changed, 18 insertions(+)

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index b2fc8d7..3597dc8 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1114,6 +1114,15 @@ static int uart_get_icount(struct tty_struct *tty,
 	return 0;
 }
 
+static int uart_pm(struct tty_struct *tty, enum tty_pm_state state)
+{
+	struct uart_state *ustate = tty->driver_data;
+
+	uart_change_pm(ustate, state);
+
+	return 0;
+}
+
 /*
  * Called via sys_ioctl.  We can use spin_lock_irq() here.
  */
@@ -2217,6 +2226,7 @@ static const struct tty_operations uart_ops = {
 	.tiocmget	= uart_tiocmget,
 	.tiocmset	= uart_tiocmset,
 	.get_icount	= uart_get_icount,
+	.pm		= uart_pm,
 #ifdef CONFIG_CONSOLE_POLL
 	.poll_init	= uart_poll_init,
 	.poll_get_char	= uart_poll_get_char,
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index d150a6f..ba34b7f 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -229,6 +229,12 @@
  *	Called when the device receives a TIOCGICOUNT ioctl. Passed a kernel
  *	structure to complete. This method is optional and will only be called
  *	if provided (otherwise EINVAL will be returned).
+ *
+ * int (*pm)(struct tty_struct * tty, enum tty_pm_state state);
+ *
+ *      Perform any power management related activities on the specified
+ *      tty. State indicates the new state.
+ *
  */
 
 #include <linux/export.h>
@@ -249,6 +255,7 @@ struct serial_icounter_struct;
  */
 enum tty_pm_state {
 	TTY_PM_STATE_ON = 0,
+	TTY_PM_STATE_SLEEP,
 	TTY_PM_STATE_OFF = 3, /* number taken from ACPI */
 	TTY_PM_STATE_UNDEFINED,
 };
@@ -290,6 +297,7 @@ struct tty_operations {
 	int (*set_termiox)(struct tty_struct *tty, struct termiox *tnew);
 	int (*get_icount)(struct tty_struct *tty,
 				struct serial_icounter_struct *icount);
+	int (*pm)(struct tty_struct *tty, enum tty_pm_state state);
 #ifdef CONFIG_CONSOLE_POLL
 	int (*poll_init)(struct tty_driver *driver, int line, char *options);
 	int (*poll_get_char)(struct tty_driver *driver, int line);
-- 
1.8.0

Re: [PATCH 2/2] TTY: serial, add pm function

[Rickard Andersson]

On 12/10/2012 01:34 PM, Rickard ANDERSSON wrote:
> Add power management function to tty driver interface
> and add implementation for serial core.
>
> Signed-off-by: Rickard Andersson<rickard.andersson@stericsson.com>
> ---
>   drivers/tty/serial/serial_core.c | 10 ++++++++++
>   include/linux/tty_driver.h       |  8 ++++++++
>   2 files changed, 18 insertions(+)
>
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> index b2fc8d7..3597dc8 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -1114,6 +1114,15 @@ static int uart_get_icount(struct tty_struct *tty,
>   	return 0;
>   }
>
> +static int uart_pm(struct tty_struct *tty, enum tty_pm_state state)
> +{
> +	struct uart_state *ustate = tty->driver_data;
> +
> +	uart_change_pm(ustate, state);
I just realized that I should hold "port->mutex" while calling 
uart_change_pm(..).

I am waiting for further comments on the patch set.

BR
Rickard