@@ -216,6 +216,7 @@ struct imx_port {
unsigned int tx_bytes;
unsigned int dma_tx_nents;
wait_queue_head_t dma_wait;
+ unsigned int saved_reg[10];
};
struct imx_port_ucrs {
@@ -1811,36 +1812,6 @@ static struct uart_driver imx_reg = {
.cons = IMX_CONSOLE,
};
-static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
-{
- struct imx_port *sport = platform_get_drvdata(dev);
- unsigned int val;
-
- /* enable wakeup from i.MX UART */
- val = readl(sport->port.membase + UCR3);
- val |= UCR3_AWAKEN;
- writel(val, sport->port.membase + UCR3);
-
- uart_suspend_port(&imx_reg, &sport->port);
-
- return 0;
-}
-
-static int serial_imx_resume(struct platform_device *dev)
-{
- struct imx_port *sport = platform_get_drvdata(dev);
- unsigned int val;
-
- /* disable wakeup from i.MX UART */
- val = readl(sport->port.membase + UCR3);
- val &= ~UCR3_AWAKEN;
- writel(val, sport->port.membase + UCR3);
-
- uart_resume_port(&imx_reg, &sport->port);
-
- return 0;
-}
-
#ifdef CONFIG_OF
/*
* This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
@@ -1992,16 +1963,109 @@ static int serial_imx_remove(struct platform_device *pdev)
return uart_remove_one_port(&imx_reg, &sport->port);
}
+static int imx_serial_port_suspend_noirq(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct imx_port *sport = platform_get_drvdata(pdev);
+ int ret;
+
+ ret = clk_enable(sport->clk_ipg);
+ if (ret)
+ dev_err(dev, "UART%d suspend error!\r\n", sport->port.line);
+
+ /* Save necessary regs */
+ sport->saved_reg[0] = readl(sport->port.membase + UCR1);
+ sport->saved_reg[1] = readl(sport->port.membase + UCR2);
+ sport->saved_reg[2] = readl(sport->port.membase + UCR3);
+ sport->saved_reg[3] = readl(sport->port.membase + UCR4);
+ sport->saved_reg[4] = readl(sport->port.membase + UFCR);
+ sport->saved_reg[5] = readl(sport->port.membase + UESC);
+ sport->saved_reg[6] = readl(sport->port.membase + UTIM);
+ sport->saved_reg[7] = readl(sport->port.membase + UBIR);
+ sport->saved_reg[8] = readl(sport->port.membase + UBMR);
+ sport->saved_reg[9] = readl(sport->port.membase + IMX21_UTS);
+
+ if (ret == 0)
+ clk_disable(sport->clk_ipg);
+
+ return 0;
+}
+
+static int imx_serial_port_resume_noirq(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct imx_port *sport = platform_get_drvdata(pdev);
+ int ret;
+
+ ret = clk_enable(sport->clk_ipg);
+ if (ret)
+ dev_err(dev, "UART%d resume error!\r\n", sport->port.line);
+
+ writel(sport->saved_reg[4], sport->port.membase + UFCR);
+ writel(sport->saved_reg[5], sport->port.membase + UESC);
+ writel(sport->saved_reg[6], sport->port.membase + UTIM);
+ writel(sport->saved_reg[7], sport->port.membase + UBIR);
+ writel(sport->saved_reg[8], sport->port.membase + UBMR);
+ writel(sport->saved_reg[9], sport->port.membase + IMX21_UTS);
+ writel(sport->saved_reg[0], sport->port.membase + UCR1);
+ writel(sport->saved_reg[1] | UCR2_SRST, sport->port.membase + UCR2);
+ writel(sport->saved_reg[2], sport->port.membase + UCR3);
+ writel(sport->saved_reg[3], sport->port.membase + UCR4);
+
+ if (ret == 0)
+ clk_disable(sport->clk_ipg);
+
+ return 0;
+}
+
+static int imx_serial_port_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct imx_port *sport = platform_get_drvdata(pdev);
+ unsigned int val;
+
+ /* enable wakeup from i.MX UART */
+ val = readl(sport->port.membase + UCR3);
+ val |= UCR3_AWAKEN;
+ writel(val, sport->port.membase + UCR3);
+
+ uart_suspend_port(&imx_reg, &sport->port);
+
+ return 0;
+}
+
+static int imx_serial_port_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct imx_port *sport = platform_get_drvdata(pdev);
+ unsigned int val;
+
+ /* disable wakeup from i.MX UART */
+ val = readl(sport->port.membase + UCR3);
+ val &= ~UCR3_AWAKEN;
+ writel(val, sport->port.membase + UCR3);
+
+ uart_resume_port(&imx_reg, &sport->port);
+
+ return 0;
+}
+
+static const struct dev_pm_ops imx_serial_port_pm_ops = {
+ .suspend_noirq = imx_serial_port_suspend_noirq,
+ .resume_noirq = imx_serial_port_resume_noirq,
+ .suspend = imx_serial_port_suspend,
+ .resume = imx_serial_port_resume,
+};
+
static struct platform_driver serial_imx_driver = {
.probe = serial_imx_probe,
.remove = serial_imx_remove,
- .suspend = serial_imx_suspend,
- .resume = serial_imx_resume,
.id_table = imx_uart_devtype,
.driver = {
.name = "imx-uart",
.of_match_table = imx_uart_dt_ids,
+ .pm = &imx_serial_port_pm_ops,
},
};
When system goes into low power states like SUSPEND_MEM and HIBERNATION, the hardware IP block may be powered off to reduce the power consumption. This power down may cause problems on some imx platforms, because the hardware settings are reset to its power on default values which may differ from the ones when it power off. This patch added the dev_pm_ops and implemented two callbacks: suspend_noirq and resume_noirq, which will save the necessory hardware parameters right before power down and recover them before system uses the hardware. Because added the dev_pm_ops, the old suspend/resume callbacks under platform_driver will not be called any more. Changed their prototypes and moved those two callbacks into dev_pm_ops too. Signed-off-by: Shenwei Wang <shenwei.wang@freescale.com> --- Change log: PATCH v4 Added the return value check for clk_enable. Replace the number 0x1 with UCR2_SRST. PATCH v3 After added the dev_pm_ops, the old suspend/resume callbacks under platform_driver will not be called. Changed their prototypes and moved them into dev_pm_ops too. PATCH v2 Change pr_debug to dev_dbg per GregK's review feedback. drivers/tty/serial/imx.c | 128 +++++++++++++++++++++++++++++++++++------------ 1 file changed, 96 insertions(+), 32 deletions(-) -- 2.5.0.rc2