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

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This patch adds power management for the Spreadtrum serial controller.

Signed-off-by: Lanqing Liu <lanqing.liu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Lanqing Liu 2019-03-04 16:58:22 +08:00 committed by Greg Kroah-Hartman
parent 984df54e43
commit 4007098f4c
1 changed files with 57 additions and 4 deletions
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61
drivers/tty/serial/sprd_serial.c
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@ -100,10 +100,12 @@
#define SPRD_IMSR_TX_FIFO_EMPTY BIT(1) #define SPRD_IMSR_TX_FIFO_EMPTY BIT(1)
#define SPRD_IMSR_BREAK_DETECT BIT(7) #define SPRD_IMSR_BREAK_DETECT BIT(7)
#define SPRD_IMSR_TIMEOUT BIT(13) #define SPRD_IMSR_TIMEOUT BIT(13)
#define SPRD_DEFAULT_SOURCE_CLK 26000000
struct sprd_uart_port { struct sprd_uart_port {
struct uart_port port; struct uart_port port;
char name[16]; char name[16];
struct clk *clk;
}; };
static struct sprd_uart_port *sprd_port[UART_NR_MAX]; 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; 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 = { static const struct uart_ops serial_sprd_ops = {
.tx_empty = sprd_tx_empty, .tx_empty = sprd_tx_empty,
.get_mctrl = sprd_get_mctrl, .get_mctrl = sprd_get_mctrl,
@ -507,6 +525,7 @@ static const struct uart_ops serial_sprd_ops = {
.request_port = sprd_request_port, .request_port = sprd_request_port,
.config_port = sprd_config_port, .config_port = sprd_config_port,
.verify_port = sprd_verify_port, .verify_port = sprd_verify_port,
.pm = sprd_pm,
}; };
#ifdef CONFIG_SERIAL_SPRD_CONSOLE #ifdef CONFIG_SERIAL_SPRD_CONSOLE
@ -671,11 +690,45 @@ static int sprd_remove(struct platform_device *dev)
return 0; 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) static int sprd_probe(struct platform_device *pdev)
{ {
struct resource *res; struct resource *res;
struct uart_port *up; struct uart_port *up;
struct clk *clk;
int irq; int irq;
int index; int index;
int ret; int ret;
@ -704,9 +757,9 @@ static int sprd_probe(struct platform_device *pdev)
up->ops = &serial_sprd_ops; up->ops = &serial_sprd_ops;
up->flags = UPF_BOOT_AUTOCONF; up->flags = UPF_BOOT_AUTOCONF;
clk = devm_clk_get(&pdev->dev, NULL); ret = sprd_clk_init(up);
if (!IS_ERR_OR_NULL(clk)) if (ret)
up->uartclk = clk_get_rate(clk); return ret;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0); res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
up->membase = devm_ioremap_resource(&pdev->dev, res); up->membase = devm_ioremap_resource(&pdev->dev, res);