From fc60861b91c6585740e9a502fa4008b2f4694b22 Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Thu, 27 Nov 2014 21:52:45 +0100 Subject: tty: serial: fsl_lpuart: support suspend/resume In order to allow wake support in STOP sleep mode, clocks are needed. Use imx_clk_gate2_cgr to disable automatic clock gating in low power mode STOP. This allows to enable wake by UART using: echo enabled > /sys/class/tty/ttyLP0/power/wakeup However, if wake is not enabled, the driver should disable the clocks explicitly to save power. --- arch/arm/mach-imx/clk-vf610.c | 12 ++++++------ drivers/tty/serial/fsl_lpuart.c | 16 ++++++++++++++-- 2 files changed, 20 insertions(+), 8 deletions(-) diff --git a/arch/arm/mach-imx/clk-vf610.c b/arch/arm/mach-imx/clk-vf610.c index 0f4dc927a29a..016c547e7827 100644 --- a/arch/arm/mach-imx/clk-vf610.c +++ b/arch/arm/mach-imx/clk-vf610.c @@ -316,12 +316,12 @@ static void __init vf610_clocks_init(struct device_node *ccm_node) clk[VF610_CLK_PIT] = imx_clk_gate2("pit", "ipg_bus", CCM_CCGR1, CCM_CCGRx_CGn(7)); - clk[VF610_CLK_UART0] = imx_clk_gate2("uart0", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(7)); - clk[VF610_CLK_UART1] = imx_clk_gate2("uart1", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(8)); - clk[VF610_CLK_UART2] = imx_clk_gate2("uart2", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(9)); - clk[VF610_CLK_UART3] = imx_clk_gate2("uart3", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(10)); - clk[VF610_CLK_UART4] = imx_clk_gate2("uart4", "ipg_bus", CCM_CCGR6, CCM_CCGRx_CGn(9)); - clk[VF610_CLK_UART5] = imx_clk_gate2("uart5", "ipg_bus", CCM_CCGR6, CCM_CCGRx_CGn(10)); + clk[VF610_CLK_UART0] = imx_clk_gate2_cgr("uart0", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(7), 0x2); + clk[VF610_CLK_UART1] = imx_clk_gate2_cgr("uart1", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(8), 0x2); + clk[VF610_CLK_UART2] = imx_clk_gate2_cgr("uart2", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(9), 0x2); + clk[VF610_CLK_UART3] = imx_clk_gate2_cgr("uart3", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(10), 0x2); + clk[VF610_CLK_UART4] = imx_clk_gate2_cgr("uart4", "ipg_bus", CCM_CCGR6, CCM_CCGRx_CGn(9), 0x2); + clk[VF610_CLK_UART5] = imx_clk_gate2_cgr("uart5", "ipg_bus", CCM_CCGR6, CCM_CCGRx_CGn(10), 0x2); clk[VF610_CLK_I2C0] = imx_clk_gate2("i2c0", "ipg_bus", CCM_CCGR4, CCM_CCGRx_CGn(6)); clk[VF610_CLK_I2C1] = imx_clk_gate2("i2c1", "ipg_bus", CCM_CCGR4, CCM_CCGRx_CGn(7)); diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 08ce76f4f261..25f395bf3d46 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -483,9 +483,8 @@ static void lpuart_dma_rx_complete(void *arg) spin_unlock_irqrestore(&sport->port.lock, flags); } -static void lpuart_timer_func(unsigned long data) +static void lpuart_dma_rx_terminate(struct lpuart_port *sport) { - struct lpuart_port *sport = (struct lpuart_port *)data; struct tty_port *port = &sport->port.state->port; struct dma_tx_state state; unsigned long flags; @@ -510,6 +509,11 @@ static void lpuart_timer_func(unsigned long data) spin_unlock_irqrestore(&sport->port.lock, flags); } +static void lpuart_timer_func(unsigned long data) +{ + lpuart_dma_rx_terminate((struct lpuart_port *)data); +} + static inline void lpuart_prepare_rx(struct lpuart_port *sport) { unsigned long flags; @@ -1876,7 +1880,12 @@ static int lpuart_suspend(struct device *dev) writeb(temp, sport->port.membase + UARTCR2); } + if (sport->dma_rx_in_progress) + lpuart_dma_rx_terminate(sport); + uart_suspend_port(&lpuart_reg, &sport->port); + if (sport->port.suspended && !sport->port.irq_wake) + clk_disable_unprepare(sport->clk); return 0; } @@ -1886,6 +1895,9 @@ static int lpuart_resume(struct device *dev) struct lpuart_port *sport = dev_get_drvdata(dev); unsigned long temp; + if (sport->port.suspended && !sport->port.irq_wake) + clk_prepare_enable(sport->clk); + if (sport->lpuart32) { lpuart32_setup_watermark(sport); temp = lpuart32_read(sport->port.membase + UARTCTRL); -- cgit v1.2.3