+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"
+@@ -846,6 +847,20 @@ 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)
+ {
+@@ -2259,6 +2274,7 @@ 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,
+@@ -2283,6 +2299,7 @@ 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,
+@@ -2742,6 +2759,11 @@ 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;
+@@ -2776,6 +2798,9 @@ 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);
+ failed_clock_enable:
+@@ -2802,15 +2827,41 @@ 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 */
+@@ -2824,10 +2875,14 @@ 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) {
+ /*
+@@ -2858,9 +2913,6 @@ 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;
+ }
+
+@@ -2868,9 +2920,11 @@ 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);
+@@ -2891,13 +2945,23 @@ 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,
+@@ -2905,7 +2969,7 @@ 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,
+ },
+ };
+
projects / openwrt / staging / wigyori.git / blobdiff