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Commit 4007098f authored by Lanqing Liu's avatar Lanqing Liu Committed by Greg Kroah-Hartman
Browse files

serial: sprd: Add power management for the Spreadtrum serial controller 



This patch adds power management for the Spreadtrum serial controller.

Signed-off-by: default avatarLanqing Liu <lanqing.liu@unisoc.com>
Signed-off-by: default avatarBaolin Wang <baolin.wang@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 984df54e

drivers/tty/serial/sprd_serial.c

+57 −4
Original line number Diff line number Diff line
@@ -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);