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From ff3d8063eed907bed728a14e1519dc659036315a Mon Sep 17 00:00:00 2001
From: Fugang Duan <fugang.duan@nxp.com>
Date: Wed, 11 Sep 2019 16:36:48 +0800
Subject: [PATCH] MLK-17133-02 tty: serial: lpuart: add runtime pm support
Add runtime pm support to manage lpuart clock and its power domain
to save power in system idle and system suspend stages.
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Reviewed-by: Robin Gong <yibin.gong@nxp.com>
---
drivers/tty/serial/fsl_lpuart.c | 80 ++++++++++++++++++++++++++++++++++++-----
1 file changed, 72 insertions(+), 8 deletions(-)
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -245,6 +245,7 @@
/* Rx DMA timeout in ms, which is used to calculate Rx ring buffer size */
#define DMA_RX_TIMEOUT (10)
+#define UART_AUTOSUSPEND_TIMEOUT 3000
#define DRIVER_NAME "fsl-lpuart"
#define DEV_NAME "ttyLP"
@@ -856,6 +857,20 @@ static void lpuart32_start_tx(struct uar
}
}
+static void
+lpuart_uart_pm(struct uart_port *port, unsigned int state, unsigned int oldstate)
+{
+ switch (state) {
+ case UART_PM_STATE_OFF:
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
+ break;
+ default:
+ pm_runtime_get_sync(port->dev);
+ break;
+ }
+}
+
/* return TIOCSER_TEMT when transmitter is not busy */
static unsigned int lpuart_tx_empty(struct uart_port *port)
{
@@ -2309,6 +2324,7 @@ static const struct uart_ops lpuart_pops
.break_ctl = lpuart_break_ctl,
.startup = lpuart_startup,
.shutdown = lpuart_shutdown,
+ .pm = lpuart_uart_pm,
.set_termios = lpuart_set_termios,
.type = lpuart_type,
.request_port = lpuart_request_port,
@@ -2333,6 +2349,7 @@ static const struct uart_ops lpuart32_po
.break_ctl = lpuart32_break_ctl,
.startup = lpuart32_startup,
.shutdown = lpuart32_shutdown,
+ .pm = lpuart_uart_pm,
.set_termios = lpuart32_set_termios,
.type = lpuart_type,
.request_port = lpuart_request_port,
@@ -2790,6 +2807,11 @@ static int lpuart_probe(struct platform_
if (ret)
goto failed_irq_request;
+ pm_runtime_use_autosuspend(&pdev->dev);
+ pm_runtime_set_autosuspend_delay(&pdev->dev, UART_AUTOSUSPEND_TIMEOUT);
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+
ret = uart_add_one_port(&lpuart_reg, &sport->port);
if (ret)
goto failed_attach_port;
@@ -2824,6 +2846,9 @@ static int lpuart_probe(struct platform_
failed_reset:
uart_remove_one_port(&lpuart_reg, &sport->port);
failed_attach_port:
+ pm_runtime_disable(&pdev->dev);
+ pm_runtime_set_suspended(&pdev->dev);
+ pm_runtime_dont_use_autosuspend(&pdev->dev);
failed_irq_request:
lpuart_disable_clks(sport);
return ret;
@@ -2843,15 +2868,41 @@ static int lpuart_remove(struct platform
if (sport->dma_rx_chan)
dma_release_channel(sport->dma_rx_chan);
+ pm_runtime_disable(&pdev->dev);
+ pm_runtime_set_suspended(&pdev->dev);
+ pm_runtime_dont_use_autosuspend(&pdev->dev);
return 0;
}
#ifdef CONFIG_PM_SLEEP
+static int lpuart_runtime_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct lpuart_port *sport = platform_get_drvdata(pdev);
+
+ lpuart_disable_clks(sport);
+
+ return 0;
+};
+
+static int lpuart_runtime_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct lpuart_port *sport = platform_get_drvdata(pdev);
+
+ return lpuart_enable_clks(sport);
+};
+
static int lpuart_suspend(struct device *dev)
{
struct lpuart_port *sport = dev_get_drvdata(dev);
unsigned long temp;
bool irq_wake;
+ int ret;
+
+ ret = clk_prepare_enable(sport->ipg_clk);
+ if (ret)
+ return ret;
if (lpuart_is_32(sport)) {
/* disable Rx/Tx and interrupts */
@@ -2865,10 +2916,14 @@ static int lpuart_suspend(struct device
writeb(temp, sport->port.membase + UARTCR2);
}
+ clk_disable_unprepare(sport->ipg_clk);
+
uart_suspend_port(&lpuart_reg, &sport->port);
/* uart_suspend_port() might set wakeup flag */
irq_wake = irqd_is_wakeup_set(irq_get_irq_data(sport->port.irq));
+ if (sport->port.suspended && !irq_wake)
+ return 0;
if (sport->lpuart_dma_rx_use) {
/*
@@ -2899,9 +2954,6 @@ static int lpuart_suspend(struct device
dmaengine_terminate_all(sport->dma_tx_chan);
}
- if (sport->port.suspended && !irq_wake)
- lpuart_disable_clks(sport);
-
return 0;
}
@@ -2909,9 +2961,11 @@ static int lpuart_resume(struct device *
{
struct lpuart_port *sport = dev_get_drvdata(dev);
bool irq_wake = irqd_is_wakeup_set(irq_get_irq_data(sport->port.irq));
+ int ret;
- if (sport->port.suspended && !irq_wake)
- lpuart_enable_clks(sport);
+ ret = clk_prepare_enable(sport->ipg_clk);
+ if (ret)
+ return ret;
if (lpuart_is_32(sport))
lpuart32_setup_watermark_enable(sport);
@@ -2932,13 +2986,23 @@ static int lpuart_resume(struct device *
if (lpuart_is_32(sport))
lpuart32_configure(sport);
+ clk_disable_unprepare(sport->ipg_clk);
+
uart_resume_port(&lpuart_reg, &sport->port);
return 0;
}
-#endif
+static const struct dev_pm_ops lpuart_pm_ops = {
+ SET_RUNTIME_PM_OPS(lpuart_runtime_suspend,
+ lpuart_runtime_resume, NULL)
+ SET_SYSTEM_SLEEP_PM_OPS(lpuart_suspend, lpuart_resume)
+};
+#define SERIAL_LPUART_PM_OPS (&lpuart_pm_ops)
-static SIMPLE_DEV_PM_OPS(lpuart_pm_ops, lpuart_suspend, lpuart_resume);
+#else /* !CONFIG_PM_SLEEP */
+
+#define SERIAL_LPUART_PM_OPS NULL
+#endif
static struct platform_driver lpuart_driver = {
.probe = lpuart_probe,
@@ -2946,7 +3010,7 @@ static struct platform_driver lpuart_dri
.driver = {
.name = "fsl-lpuart",
.of_match_table = lpuart_dt_ids,
- .pm = &lpuart_pm_ops,
+ .pm = SERIAL_LPUART_PM_OPS,
},
};
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