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ARM: OMAP2+: UART: Add runtime pm support for omap-serial driver
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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: Govindraj.R <govindraj.raja@ti.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Kevin Hilman <khilman@ti.com>
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Govindraj.R authored and Kevin Hilman committed Dec 15, 2011
1 parent edd70ad commit fcdca75
Showing 1 changed file with 109 additions and 13 deletions.
122 changes: 109 additions & 13 deletions drivers/tty/serial/omap-serial.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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 */
Expand Down Expand Up @@ -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);
}
}

Expand All @@ -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)
Expand All @@ -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)
Expand Down Expand Up @@ -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;
}

Expand All @@ -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,
Expand Down Expand 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);
Expand All @@ -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;
}
Expand All @@ -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;
}

Expand All @@ -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)
Expand Down Expand Up @@ -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)
Expand All @@ -443,13 +477,15 @@ 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;
else
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)
Expand All @@ -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())
Expand Down Expand Up @@ -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;
}
Expand All @@ -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
*/
Expand Down Expand Up @@ -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);
}

Expand Down Expand 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);

/*
Expand Down Expand Up @@ -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);
}

Expand All @@ -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);
Expand All @@ -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)
Expand Down Expand Up @@ -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 */
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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)
{
Expand Down Expand Up @@ -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,
Expand Down Expand Up @@ -1299,13 +1368,22 @@ 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);

ret = uart_add_one_port(&serial_omap_reg, &up->port);
if (ret != 0)
goto do_release_region;

pm_runtime_put(&pdev->dev);
platform_set_drvdata(pdev, up);
return 0;
err:
Expand All @@ -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,
},
};

Expand Down

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