From 4007098f4ce46c87c16ba34ddc00b042aa444b59 Mon Sep 17 00:00:00 2001 From: Lanqing Liu Date: Mon, 4 Mar 2019 16:58:22 +0800 Subject: serial: sprd: Add power management for the Spreadtrum serial controller This patch adds power management for the Spreadtrum serial controller. Signed-off-by: Lanqing Liu Signed-off-by: Baolin Wang Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sprd_serial.c | 61 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 57 insertions(+), 4 deletions(-) (limited to 'drivers/tty/serial') diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c index 1891a45ac05d..8f45b6671c19 100644 --- a/drivers/tty/serial/sprd_serial.c +++ b/drivers/tty/serial/sprd_serial.c @@ -100,10 +100,12 @@ #define SPRD_IMSR_TX_FIFO_EMPTY BIT(1) #define SPRD_IMSR_BREAK_DETECT BIT(7) #define SPRD_IMSR_TIMEOUT BIT(13) +#define SPRD_DEFAULT_SOURCE_CLK 26000000 struct sprd_uart_port { struct uart_port port; char name[16]; + struct clk *clk; }; static struct sprd_uart_port *sprd_port[UART_NR_MAX]; @@ -491,6 +493,22 @@ static int sprd_verify_port(struct uart_port *port, struct serial_struct *ser) return 0; } +static void sprd_pm(struct uart_port *port, unsigned int state, + unsigned int oldstate) +{ + struct sprd_uart_port *sup = + container_of(port, struct sprd_uart_port, port); + + switch (state) { + case UART_PM_STATE_ON: + clk_prepare_enable(sup->clk); + break; + case UART_PM_STATE_OFF: + clk_disable_unprepare(sup->clk); + break; + } +} + static const struct uart_ops serial_sprd_ops = { .tx_empty = sprd_tx_empty, .get_mctrl = sprd_get_mctrl, @@ -507,6 +525,7 @@ static const struct uart_ops serial_sprd_ops = { .request_port = sprd_request_port, .config_port = sprd_config_port, .verify_port = sprd_verify_port, + .pm = sprd_pm, }; #ifdef CONFIG_SERIAL_SPRD_CONSOLE @@ -671,11 +690,45 @@ static int sprd_remove(struct platform_device *dev) return 0; } +static int sprd_clk_init(struct uart_port *uport) +{ + struct clk *clk_uart, *clk_parent; + struct sprd_uart_port *u = sprd_port[uport->line]; + + clk_uart = devm_clk_get(uport->dev, "uart"); + if (IS_ERR(clk_uart)) { + dev_warn(uport->dev, "uart%d can't get uart clock\n", + uport->line); + clk_uart = NULL; + } + + clk_parent = devm_clk_get(uport->dev, "source"); + if (IS_ERR(clk_parent)) { + dev_warn(uport->dev, "uart%d can't get source clock\n", + uport->line); + clk_parent = NULL; + } + + if (!clk_uart || clk_set_parent(clk_uart, clk_parent)) + uport->uartclk = SPRD_DEFAULT_SOURCE_CLK; + else + uport->uartclk = clk_get_rate(clk_uart); + + u->clk = devm_clk_get(uport->dev, "enable"); + if (IS_ERR(u->clk)) { + if (PTR_ERR(u->clk) != -EPROBE_DEFER) + dev_err(uport->dev, "uart%d can't get enable clock\n", + uport->line); + return PTR_ERR(u->clk); + } + + return 0; +} + static int sprd_probe(struct platform_device *pdev) { struct resource *res; struct uart_port *up; - struct clk *clk; int irq; int index; int ret; @@ -704,9 +757,9 @@ static int sprd_probe(struct platform_device *pdev) up->ops = &serial_sprd_ops; up->flags = UPF_BOOT_AUTOCONF; - clk = devm_clk_get(&pdev->dev, NULL); - if (!IS_ERR_OR_NULL(clk)) - up->uartclk = clk_get_rate(clk); + ret = sprd_clk_init(up); + if (ret) + return ret; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); up->membase = devm_ioremap_resource(&pdev->dev, res); -- cgit v1.2.3