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Commit fcdca757 authored by Govindraj.R's avatar Govindraj.R Committed by Kevin Hilman
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ARM: OMAP2+: UART: Add runtime pm support for omap-serial driver 



Adapts omap-serial driver to use pm_runtime API's.
Use runtime runtime API's to handle uart clocks and obtain
device_usage statics. Set runtime API's usage to irq_safe so that
we can use get_sync from irq context. Auto-suspend for port specific
activities and put for reg access. Moving suspend/resume hooks
to dev_pm_ops structure and bind with config_suspend to avoid any
compilation warning if config_suspend is disabled.

By default uart autosuspend delay is set to -1 to avoid character loss
if uart's are autoidled and woken up on rx pin.

After boot up UART's can be autoidled by setting autosuspend delay from sysfs.

echo 3000 > /sys/devices/platform/omap/omap_uart.X/power/autosuspend_delay_ms
X=0,1,2,3 for UART1/2/3/4. Number of uarts available may vary across omap_soc.

Also if uart is not wakeup capable we can prevent runtime autosuspend by
forbiding runtime.

Signed-off-by: default avatarGovindraj.R <govindraj.raja@ti.com>
Acked-by: default avatarAlan Cox <alan@linux.intel.com>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: default avatarKevin Hilman <khilman@ti.com>
parent edd70ad7

drivers/tty/serial/omap-serial.c

+109 −13
Original line number Diff line number Diff line
@@ -37,11 +37,14 @@ 
#include <linux/clk.h>

#include <linux/serial_core.h>

#include <linux/irq.h>

#include <linux/pm_runtime.h>



#include <plat/dma.h>

#include <plat/dmtimer.h>

#include <plat/omap-serial.h>



#define OMAP_UART_AUTOSUSPEND_DELAY -1



static struct uart_omap_port *ui[OMAP_MAX_HSUART_PORTS];



/* Forward declaration of functions */
@@ -102,6 +105,8 @@ static void serial_omap_stop_rxdma(struct uart_omap_port *up) 
		omap_free_dma(up->uart_dma.rx_dma_channel);

		up->uart_dma.rx_dma_channel = OMAP_UART_DMA_CH_FREE;

		up->uart_dma.rx_dma_used = false;

		pm_runtime_mark_last_busy(&up->pdev->dev);

		pm_runtime_put_autosuspend(&up->pdev->dev);

	}

}
@@ -110,8 +115,11 @@ static void serial_omap_enable_ms(struct uart_port *port) 
	struct uart_omap_port *up = (struct uart_omap_port *)port;



	dev_dbg(up->port.dev, "serial_omap_enable_ms+%d\n", up->pdev->id);



	pm_runtime_get_sync(&up->pdev->dev);

	up->ier |= UART_IER_MSI;

	serial_out(up, UART_IER, up->ier);

	pm_runtime_put(&up->pdev->dev);

}



static void serial_omap_stop_tx(struct uart_port *port)
@@ -129,23 +137,32 @@ static void serial_omap_stop_tx(struct uart_port *port) 
		omap_stop_dma(up->uart_dma.tx_dma_channel);

		omap_free_dma(up->uart_dma.tx_dma_channel);

		up->uart_dma.tx_dma_channel = OMAP_UART_DMA_CH_FREE;

		pm_runtime_mark_last_busy(&up->pdev->dev);

		pm_runtime_put_autosuspend(&up->pdev->dev);

	}



	pm_runtime_get_sync(&up->pdev->dev);

	if (up->ier & UART_IER_THRI) {

		up->ier &= ~UART_IER_THRI;

		serial_out(up, UART_IER, up->ier);

	}



	pm_runtime_mark_last_busy(&up->pdev->dev);

	pm_runtime_put_autosuspend(&up->pdev->dev);

}



static void serial_omap_stop_rx(struct uart_port *port)

{

	struct uart_omap_port *up = (struct uart_omap_port *)port;



	pm_runtime_get_sync(&up->pdev->dev);

	if (up->use_dma)

		serial_omap_stop_rxdma(up);

	up->ier &= ~UART_IER_RLSI;

	up->port.read_status_mask &= ~UART_LSR_DR;

	serial_out(up, UART_IER, up->ier);

	pm_runtime_mark_last_busy(&up->pdev->dev);

	pm_runtime_put_autosuspend(&up->pdev->dev);

}



static inline void receive_chars(struct uart_omap_port *up, int *status)
@@ -262,7 +279,10 @@ static void serial_omap_start_tx(struct uart_port *port) 
	int ret = 0;



	if (!up->use_dma) {

		pm_runtime_get_sync(&up->pdev->dev);

		serial_omap_enable_ier_thri(up);

		pm_runtime_mark_last_busy(&up->pdev->dev);

		pm_runtime_put_autosuspend(&up->pdev->dev);

		return;

	}
@@ -272,6 +292,7 @@ static void serial_omap_start_tx(struct uart_port *port) 
	xmit = &up->port.state->xmit;



	if (up->uart_dma.tx_dma_channel == OMAP_UART_DMA_CH_FREE) {

		pm_runtime_get_sync(&up->pdev->dev);

		ret = omap_request_dma(up->uart_dma.uart_dma_tx,

				"UART Tx DMA",

				(void *)uart_tx_dma_callback, up,
@@ -354,9 +375,13 @@ static inline irqreturn_t serial_omap_irq(int irq, void *dev_id) 
	unsigned int iir, lsr;

	unsigned long flags;



	pm_runtime_get_sync(&up->pdev->dev);

	iir = serial_in(up, UART_IIR);

	if (iir & UART_IIR_NO_INT)

	if (iir & UART_IIR_NO_INT) {

		pm_runtime_mark_last_busy(&up->pdev->dev);

		pm_runtime_put_autosuspend(&up->pdev->dev);

		return IRQ_NONE;

	}



	spin_lock_irqsave(&up->port.lock, flags);

	lsr = serial_in(up, UART_LSR);
@@ -378,6 +403,9 @@ static inline irqreturn_t serial_omap_irq(int irq, void *dev_id) 
		transmit_chars(up);



	spin_unlock_irqrestore(&up->port.lock, flags);

	pm_runtime_mark_last_busy(&up->pdev->dev);

	pm_runtime_put_autosuspend(&up->pdev->dev);



	up->port_activity = jiffies;

	return IRQ_HANDLED;

}
@@ -388,11 +416,12 @@ static unsigned int serial_omap_tx_empty(struct uart_port *port) 
	unsigned long flags = 0;

	unsigned int ret = 0;



	pm_runtime_get_sync(&up->pdev->dev);

	dev_dbg(up->port.dev, "serial_omap_tx_empty+%d\n", up->pdev->id);

	spin_lock_irqsave(&up->port.lock, flags);

	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;

	spin_unlock_irqrestore(&up->port.lock, flags);



	pm_runtime_put(&up->pdev->dev);

	return ret;

}
@@ -402,7 +431,10 @@ static unsigned int serial_omap_get_mctrl(struct uart_port *port) 
	unsigned char status;

	unsigned int ret = 0;



	pm_runtime_get_sync(&up->pdev->dev);

	status = check_modem_status(up);

	pm_runtime_put(&up->pdev->dev);



	dev_dbg(up->port.dev, "serial_omap_get_mctrl+%d\n", up->pdev->id);



	if (status & UART_MSR_DCD)
@@ -433,8 +465,10 @@ static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl) 
	if (mctrl & TIOCM_LOOP)

		mcr |= UART_MCR_LOOP;



	pm_runtime_get_sync(&up->pdev->dev);

	mcr |= up->mcr;

	serial_out(up, UART_MCR, mcr);

	pm_runtime_put(&up->pdev->dev);

}



static void serial_omap_break_ctl(struct uart_port *port, int break_state)
@@ -443,6 +477,7 @@ static void serial_omap_break_ctl(struct uart_port *port, int break_state) 
	unsigned long flags = 0;



	dev_dbg(up->port.dev, "serial_omap_break_ctl+%d\n", up->pdev->id);

	pm_runtime_get_sync(&up->pdev->dev);

	spin_lock_irqsave(&up->port.lock, flags);

	if (break_state == -1)

		up->lcr |= UART_LCR_SBC;
@@ -450,6 +485,7 @@ static void serial_omap_break_ctl(struct uart_port *port, int break_state) 
		up->lcr &= ~UART_LCR_SBC;

	serial_out(up, UART_LCR, up->lcr);

	spin_unlock_irqrestore(&up->port.lock, flags);

	pm_runtime_put(&up->pdev->dev);

}



static int serial_omap_startup(struct uart_port *port)
@@ -468,6 +504,7 @@ static int serial_omap_startup(struct uart_port *port) 


	dev_dbg(up->port.dev, "serial_omap_startup+%d\n", up->pdev->id);



	pm_runtime_get_sync(&up->pdev->dev);

	/*

	 * Clear the FIFO buffers and disable them.

	 * (they will be reenabled in set_termios())
@@ -523,6 +560,8 @@ static int serial_omap_startup(struct uart_port *port) 
	/* Enable module level wake up */

	serial_out(up, UART_OMAP_WER, OMAP_UART_WER_MOD_WKUP);



	pm_runtime_mark_last_busy(&up->pdev->dev);

	pm_runtime_put_autosuspend(&up->pdev->dev);

	up->port_activity = jiffies;

	return 0;

}
@@ -533,6 +572,8 @@ static void serial_omap_shutdown(struct uart_port *port) 
	unsigned long flags = 0;



	dev_dbg(up->port.dev, "serial_omap_shutdown+%d\n", up->pdev->id);



	pm_runtime_get_sync(&up->pdev->dev);

	/*

	 * Disable interrupts from this port

	 */
@@ -566,6 +607,8 @@ static void serial_omap_shutdown(struct uart_port *port) 
			up->uart_dma.rx_buf_dma_phys);

		up->uart_dma.rx_buf = NULL;

	}



	pm_runtime_put(&up->pdev->dev);

	free_irq(up->port.irq, up);

}
@@ -680,6 +723,7 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios, 
	 * Ok, we're now changing the port state. Do it with

	 * interrupts disabled.

	 */

	pm_runtime_get_sync(&up->pdev->dev);

	spin_lock_irqsave(&up->port.lock, flags);



	/*
@@ -809,6 +853,7 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios, 
	serial_omap_configure_xonxoff(up, termios);



	spin_unlock_irqrestore(&up->port.lock, flags);

	pm_runtime_put(&up->pdev->dev);

	dev_dbg(up->port.dev, "serial_omap_set_termios+%d\n", up->pdev->id);

}
@@ -820,6 +865,8 @@ serial_omap_pm(struct uart_port *port, unsigned int state, 
	unsigned char efr;



	dev_dbg(up->port.dev, "serial_omap_pm+%d\n", up->pdev->id);



	pm_runtime_get_sync(&up->pdev->dev);

	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);

	efr = serial_in(up, UART_EFR);

	serial_out(up, UART_EFR, efr | UART_EFR_ECB);
@@ -829,6 +876,15 @@ serial_omap_pm(struct uart_port *port, unsigned int state, 
	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);

	serial_out(up, UART_EFR, efr);

	serial_out(up, UART_LCR, 0);



	if (!device_may_wakeup(&up->pdev->dev)) {

		if (!state)

			pm_runtime_forbid(&up->pdev->dev);

		else

			pm_runtime_allow(&up->pdev->dev);

	}



	pm_runtime_put(&up->pdev->dev);

}



static void serial_omap_release_port(struct uart_port *port)
@@ -906,19 +962,26 @@ static inline void wait_for_xmitr(struct uart_omap_port *up) 
static void serial_omap_poll_put_char(struct uart_port *port, unsigned char ch)

{

	struct uart_omap_port *up = (struct uart_omap_port *)port;



	pm_runtime_get_sync(&up->pdev->dev);

	wait_for_xmitr(up);

	serial_out(up, UART_TX, ch);

	pm_runtime_put(&up->pdev->dev);

}



static int serial_omap_poll_get_char(struct uart_port *port)

{

	struct uart_omap_port *up = (struct uart_omap_port *)port;

	unsigned int status = serial_in(up, UART_LSR);

	unsigned int status;



	pm_runtime_get_sync(&up->pdev->dev);

	status = serial_in(up, UART_LSR);

	if (!(status & UART_LSR_DR))

		return NO_POLL_CHAR;



	return serial_in(up, UART_RX);

	status = serial_in(up, UART_RX);

	pm_runtime_put(&up->pdev->dev);

	return status;

}



#endif /* CONFIG_CONSOLE_POLL */
@@ -946,6 +1009,8 @@ serial_omap_console_write(struct console *co, const char *s, 
	unsigned int ier;

	int locked = 1;



	pm_runtime_get_sync(&up->pdev->dev);



	local_irq_save(flags);

	if (up->port.sysrq)

		locked = 0;
@@ -978,6 +1043,8 @@ serial_omap_console_write(struct console *co, const char *s, 
	if (up->msr_saved_flags)

		check_modem_status(up);



	pm_runtime_mark_last_busy(&up->pdev->dev);

	pm_runtime_put_autosuspend(&up->pdev->dev);

	if (locked)

		spin_unlock(&up->port.lock);

	local_irq_restore(flags);
@@ -1060,24 +1127,25 @@ static struct uart_driver serial_omap_reg = { 
	.cons		= OMAP_CONSOLE,

};



static int

serial_omap_suspend(struct platform_device *pdev, pm_message_t state)

#ifdef CONFIG_SUSPEND

static int serial_omap_suspend(struct device *dev)

{

	struct uart_omap_port *up = platform_get_drvdata(pdev);

	struct uart_omap_port *up = dev_get_drvdata(dev);



	if (up)

		uart_suspend_port(&serial_omap_reg, &up->port);

	return 0;

}



static int serial_omap_resume(struct platform_device *dev)

static int serial_omap_resume(struct device *dev)

{

	struct uart_omap_port *up = platform_get_drvdata(dev);

	struct uart_omap_port *up = dev_get_drvdata(dev);



	if (up)

		uart_resume_port(&serial_omap_reg, &up->port);

	return 0;

}

#endif



static void serial_omap_rx_timeout(unsigned long uart_no)

{
@@ -1135,6 +1203,7 @@ static int serial_omap_start_rxdma(struct uart_omap_port *up) 
	int ret = 0;



	if (up->uart_dma.rx_dma_channel == -1) {

		pm_runtime_get_sync(&up->pdev->dev);

		ret = omap_request_dma(up->uart_dma.uart_dma_rx,

				"UART Rx DMA",

				(void *)uart_rx_dma_callback, up,
@@ -1299,6 +1368,14 @@ static int serial_omap_probe(struct platform_device *pdev) 
		up->uart_dma.rx_dma_channel = OMAP_UART_DMA_CH_FREE;

	}



	pm_runtime_use_autosuspend(&pdev->dev);

	pm_runtime_set_autosuspend_delay(&pdev->dev,

			OMAP_UART_AUTOSUSPEND_DELAY);



	pm_runtime_irq_safe(&pdev->dev);

	pm_runtime_enable(&pdev->dev);

	pm_runtime_get_sync(&pdev->dev);



	ui[pdev->id] = up;

	serial_omap_add_console_port(up);
@@ -1306,6 +1383,7 @@ static int serial_omap_probe(struct platform_device *pdev) 
	if (ret != 0)

		goto do_release_region;



	pm_runtime_put(&pdev->dev);

	platform_set_drvdata(pdev, up);

	return 0;

err:
@@ -1320,22 +1398,40 @@ static int serial_omap_remove(struct platform_device *dev) 
{

	struct uart_omap_port *up = platform_get_drvdata(dev);



	platform_set_drvdata(dev, NULL);

	if (up) {

		pm_runtime_disable(&up->pdev->dev);

		uart_remove_one_port(&serial_omap_reg, &up->port);

		kfree(up);

	}



	platform_set_drvdata(dev, NULL);

	return 0;

}



#ifdef CONFIG_PM_RUNTIME

static int serial_omap_runtime_suspend(struct device *dev)

{

	return 0;

}



static int serial_omap_runtime_resume(struct device *dev)

{

	return 0;

}

#endif



static const struct dev_pm_ops serial_omap_dev_pm_ops = {

	SET_SYSTEM_SLEEP_PM_OPS(serial_omap_suspend, serial_omap_resume)

	SET_RUNTIME_PM_OPS(serial_omap_runtime_suspend,

				serial_omap_runtime_resume, NULL)

};



static struct platform_driver serial_omap_driver = {

	.probe          = serial_omap_probe,

	.remove         = serial_omap_remove,



	.suspend	= serial_omap_suspend,

	.resume		= serial_omap_resume,

	.driver		= {

		.name	= DRIVER_NAME,

		.pm	= &serial_omap_dev_pm_ops,

	},

};