Add runtime pm and suspend/resume callback support to serial msm
driver so that clock resources are managed runtime to save power.
Signed-off-by: Pramod Gurav <pramod.gu...@linaro.org>
---
drivers/tty/serial/msm_serial.c | 183 ++++++++++++++++++++++++++++++++++++----
1 file changed, 168 insertions(+), 15 deletions(-)
diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c
index b7d80bd..6b5776a 100644
--- a/drivers/tty/serial/msm_serial.c
+++ b/drivers/tty/serial/msm_serial.c
@@ -36,6 +36,7 @@
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/of_device.h>
@@ -234,8 +235,12 @@ static void msm_stop_tx(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
+ if (pm_runtime_get_sync(port->dev) < 0)
+ return;
msm_port->imr &= ~UART_IMR_TXLEV;
msm_write(port, msm_port->imr, UART_IMR);
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
}
static void msm_start_tx(struct uart_port *port)
@@ -247,8 +252,12 @@ static void msm_start_tx(struct uart_port *port)
if (dma->count)
return;
+ if (pm_runtime_get_sync(port->dev) < 0)
+ return;
msm_port->imr |= UART_IMR_TXLEV;
msm_write(port, msm_port->imr, UART_IMR);
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
}
static void msm_reset_dm_count(struct uart_port *port, int count)
@@ -270,6 +279,8 @@ static void msm_complete_tx_dma(void *args)
unsigned int count;
u32 val;
+ if (pm_runtime_get_sync(port->dev) < 0)
+ return;
spin_lock_irqsave(&port->lock, flags);
/* Already stopped */
@@ -306,6 +317,8 @@ static void msm_complete_tx_dma(void *args)
msm_handle_tx(port);
done:
spin_unlock_irqrestore(&port->lock, flags);
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
}
static int msm_handle_tx_dma(struct msm_port *msm_port, unsigned int count)
@@ -378,6 +391,8 @@ static void msm_complete_rx_dma(void *args)
unsigned long flags;
u32 val;
+ if (pm_runtime_get_sync(port->dev) < 0)
+ return;
spin_lock_irqsave(&port->lock, flags);
/* Already stopped */
@@ -433,6 +448,8 @@ done:
if (count)
tty_flip_buffer_push(tport);
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
}
static void msm_start_rx_dma(struct msm_port *msm_port)
@@ -507,19 +524,28 @@ static void msm_stop_rx(struct uart_port *port)
struct msm_port *msm_port = UART_TO_MSM(port);
struct msm_dma *dma = &msm_port->rx_dma;
+ if (pm_runtime_get_sync(port->dev) < 0)
+ return;
msm_port->imr &= ~(UART_IMR_RXLEV | UART_IMR_RXSTALE);
msm_write(port, msm_port->imr, UART_IMR);
if (dma->chan)
msm_stop_dma(port, dma);
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
}
static void msm_enable_ms(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
+ if (pm_runtime_get_sync(port->dev) < 0)
+ return;
+
msm_port->imr |= UART_IMR_DELTA_CTS;
msm_write(port, msm_port->imr, UART_IMR);
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
}
static void msm_handle_rx_dm(struct uart_port *port, unsigned int misr)
@@ -766,6 +792,8 @@ static irqreturn_t msm_uart_irq(int irq, void *dev_id)
unsigned int misr;
u32 val;
+ if (pm_runtime_get_sync(port->dev) < 0)
+ return IRQ_NONE;
spin_lock_irqsave(&port->lock, flags);
misr = msm_read(port, UART_MISR);
msm_write(port, 0, UART_IMR); /* disable interrupt */
@@ -799,13 +827,25 @@ static irqreturn_t msm_uart_irq(int irq, void *dev_id)
msm_write(port, msm_port->imr, UART_IMR); /* restore interrupt */
spin_unlock_irqrestore(&port->lock, flags);
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
return IRQ_HANDLED;
}
static unsigned int msm_tx_empty(struct uart_port *port)
{
- return (msm_read(port, UART_SR) & UART_SR_TX_EMPTY) ? TIOCSER_TEMT : 0;
+ int ret;
+
+ ret = pm_runtime_get_sync(port->dev);
+ if (ret < 0)
+ return ret;
+
+ ret = msm_read(port, UART_SR) & UART_SR_TX_EMPTY ? TIOCSER_TEMT : 0;
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
+
+ return ret;
}
static unsigned int msm_get_mctrl(struct uart_port *port)
@@ -834,6 +874,8 @@ static void msm_set_mctrl(struct uart_port *port, unsigned
int mctrl)
{
unsigned int mr;
+ if (pm_runtime_get_sync(port->dev) < 0)
+ return;
mr = msm_read(port, UART_MR1);
if (!(mctrl & TIOCM_RTS)) {
@@ -844,14 +886,20 @@ static void msm_set_mctrl(struct uart_port *port,
unsigned int mctrl)
mr |= UART_MR1_RX_RDY_CTL;
msm_write(port, mr, UART_MR1);
}
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
}
static void msm_break_ctl(struct uart_port *port, int break_ctl)
{
+ if (pm_runtime_get_sync(port->dev) < 0)
+ return;
if (break_ctl)
msm_write(port, UART_CR_CMD_START_BREAK, UART_CR);
else
msm_write(port, UART_CR_CMD_STOP_BREAK, UART_CR);
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
}
struct msm_baud_map {
@@ -992,15 +1040,6 @@ static int msm_set_baud_rate(struct uart_port *port,
unsigned int baud,
return baud;
}
-static void msm_init_clock(struct uart_port *port)
-{
- struct msm_port *msm_port = UART_TO_MSM(port);
-
- clk_prepare_enable(msm_port->clk);
- clk_prepare_enable(msm_port->pclk);
- msm_serial_set_mnd_regs(port);
-}
-
static int msm_startup(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
@@ -1015,7 +1054,22 @@ static int msm_startup(struct uart_port *port)
if (unlikely(ret))
return ret;
- msm_init_clock(port);
+ /*
+ * UART clk must be kept enabled to
+ * avoid losing received character
+ */
+ ret = clk_prepare_enable(msm_port->clk);
+ if (ret)
+ return ret;
+ ret = clk_prepare(msm_port->pclk);
+ if (ret)
+ return ret;
+
+ ret = pm_runtime_get_sync(port->dev);
+ if (ret < 0)
+ goto err;
+
+ msm_serial_set_mnd_regs(port);
if (likely(port->fifosize > 12))
rfr_level = port->fifosize - 12;
@@ -1041,19 +1095,34 @@ static int msm_startup(struct uart_port *port)
msm_request_rx_dma(msm_port, msm_port->uart.mapbase);
}
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
+
return 0;
+
+err:
+ clk_unprepare(msm_port->pclk);
+ clk_disable_unprepare(msm_port->clk);
+ free_irq(port->irq, port);
+ return ret;
}
static void msm_shutdown(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
+ if (pm_runtime_get_sync(port->dev) < 0)
+ return;
+
msm_port->imr = 0;
msm_write(port, 0, UART_IMR); /* disable interrupts */
if (msm_port->is_uartdm)
msm_release_dma(msm_port);
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
+ clk_unprepare(msm_port->pclk);
clk_disable_unprepare(msm_port->clk);
free_irq(port->irq, port);
@@ -1067,6 +1136,8 @@ static void msm_set_termios(struct uart_port *port,
struct ktermios *termios,
unsigned long flags;
unsigned int baud, mr;
+ if (pm_runtime_get_sync(port->dev) < 0)
+ return;
spin_lock_irqsave(&port->lock, flags);
if (dma->chan) /* Terminate if any */
@@ -1140,6 +1211,8 @@ static void msm_set_termios(struct uart_port *port,
struct ktermios *termios,
msm_start_rx_dma(msm_port);
spin_unlock_irqrestore(&port->lock, flags);
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
}
static const char *msm_type(struct uart_port *port)
@@ -1220,12 +1293,26 @@ static void msm_power(struct uart_port *port, unsigned
int state,
switch (state) {
case 0:
- clk_prepare_enable(msm_port->clk);
- clk_prepare_enable(msm_port->pclk);
+ /*
+ * UART clk must be kept enabled to
+ * avoid losing received character
+ */
+ if (clk_prepare_enable(msm_port->clk))
+ return;
+ if (clk_prepare(msm_port->pclk)) {
+ clk_disable_unprepare(msm_port->clk);
+ return;
+ }
+ if (pm_runtime_get_sync(port->dev) < 0) {
+ clk_unprepare(msm_port->pclk);
+ clk_disable_unprepare(msm_port->clk);
+ return;
+ }
break;
case 3:
+ pm_runtime_put(port->dev);
+ clk_unprepare(msm_port->pclk);
clk_disable_unprepare(msm_port->clk);
- clk_disable_unprepare(msm_port->pclk);
break;
default:
pr_err("msm_serial: Unknown PM state %d\n", state);
@@ -1465,7 +1552,11 @@ static void msm_console_write(struct console *co, const
char *s,
port = msm_get_port_from_line(co->index);
msm_port = UART_TO_MSM(port);
+ if (pm_runtime_get_sync(port->dev) < 0)
+ return;
__msm_console_write(port, s, count, msm_port->is_uartdm);
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
}
static int __init msm_console_setup(struct console *co, char *options)
@@ -1484,7 +1575,7 @@ static int __init msm_console_setup(struct console *co,
char *options)
if (unlikely(!port->membase))
return -ENXIO;
- msm_init_clock(port);
+ msm_serial_set_mnd_regs(port);
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
@@ -1627,6 +1718,12 @@ static int msm_serial_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, port);
+ pm_runtime_use_autosuspend(&pdev->dev);
+ pm_runtime_set_autosuspend_delay(&pdev->dev, 500);
+ pm_runtime_irq_safe(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+ pm_runtime_set_suspended(&pdev->dev);
+
return uart_add_one_port(&msm_uart_driver, port);
}
@@ -1635,6 +1732,7 @@ static int msm_serial_remove(struct platform_device *pdev)
struct uart_port *port = platform_get_drvdata(pdev);
uart_remove_one_port(&msm_uart_driver, port);
+ pm_runtime_disable(&pdev->dev);
return 0;
}
@@ -1645,12 +1743,67 @@ static const struct of_device_id msm_match_table[] = {
{}
};
+#ifdef CONFIG_PM
+static int msm_serial_runtime_suspend(struct device *dev)
+{
+ struct uart_port *port = dev_get_drvdata(dev);
+ struct msm_port *msm_port = UART_TO_MSM(port);
+
+ if (msm_port->is_uartdm)
+ clk_disable(msm_port->pclk);
+
+ return 0;
+}
+
+static int msm_serial_runtime_resume(struct device *dev)
+{
+ struct uart_port *port = dev_get_drvdata(dev);
+ struct msm_port *msm_port = UART_TO_MSM(port);
+ int ret;
+
+ if (msm_port->is_uartdm) {
+ ret = clk_enable(msm_port->pclk);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+#endif
+
+#ifdef CONFIG_PM_SLEEP
+static int msm_serial_suspend(struct device *dev)
+{
+ struct uart_port *port = dev_get_drvdata(dev);
+
+ uart_suspend_port(&msm_uart_driver, port);
+
+ return 0;
+}
+
+static int msm_serial_resume(struct device *dev)
+{
+ struct uart_port *port = dev_get_drvdata(dev);
+
+ uart_resume_port(&msm_uart_driver, port);
+
+ return 0;
+}
+#endif
+
+static const struct dev_pm_ops msm_serial_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(msm_serial_suspend, msm_serial_resume)
+ SET_RUNTIME_PM_OPS(msm_serial_runtime_suspend,
+ msm_serial_runtime_resume, NULL)
+};
+
static struct platform_driver msm_platform_driver = {
.remove = msm_serial_remove,
.probe = msm_serial_probe,
.driver = {
.name = "msm_serial",
.of_match_table = msm_match_table,
+ .pm = &msm_serial_pm_ops,
},
};
--
1.8.2.1
