diff options
| author | Emilio López <emilio@elopez.com.ar> | 2013-03-29 00:15:49 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-28 16:19:21 -0700 |
| commit | e302cd932094fa59463b5891814d2a5ace56cfc1 (patch) | |
| tree | 64611e03d5c56f89e18a1b88105d7076ea7b9122 /drivers/tty/serial/8250/8250_dw.c | |
| parent | 38adbc54cea90e220c9212f961a621b2c6af9ae0 (diff) | |
serial: 8250_dw: add support for clk api
This commit implements support for using the clk api; this lets us use
the "clocks" property with device tree, instead of having to use
clock-frequency.
Signed-off-by: Emilio López <emilio@elopez.com.ar>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/8250/8250_dw.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_dw.c | 33 |
1 files changed, 24 insertions, 9 deletions
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index db0e66f6dd0e..3dedd2470db1 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -26,6 +26,7 @@ #include <linux/platform_device.h> #include <linux/slab.h> #include <linux/acpi.h> +#include <linux/clk.h> #include "8250.h" @@ -55,8 +56,9 @@ struct dw8250_data { - int last_lcr; - int line; + int last_lcr; + int line; + struct clk *clk; }; static void dw8250_serial_out(struct uart_port *p, int offset, int value) @@ -136,8 +138,13 @@ static int dw8250_probe_of(struct uart_port *p) if (!of_property_read_u32(np, "reg-shift", &val)) p->regshift = val; + /* clock got configured through clk api, all done */ + if (p->uartclk) + return 0; + + /* try to find out clock frequency from DT as fallback */ if (of_property_read_u32(np, "clock-frequency", &val)) { - dev_err(p->dev, "no clock-frequency property set\n"); + dev_err(p->dev, "clk or clock-frequency not defined\n"); return -EINVAL; } p->uartclk = val; @@ -294,9 +301,20 @@ static int dw8250_probe(struct platform_device *pdev) if (!uart.port.membase) return -ENOMEM; + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->clk = devm_clk_get(&pdev->dev, NULL); + if (!IS_ERR(data->clk)) { + clk_prepare_enable(data->clk); + uart.port.uartclk = clk_get_rate(data->clk); + } + uart.port.iotype = UPIO_MEM; uart.port.serial_in = dw8250_serial_in; uart.port.serial_out = dw8250_serial_out; + uart.port.private_data = data; dw8250_setup_port(&uart); @@ -312,12 +330,6 @@ static int dw8250_probe(struct platform_device *pdev) return -ENODEV; } - data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); - if (!data) - return -ENOMEM; - - uart.port.private_data = data; - data->line = serial8250_register_8250_port(&uart); if (data->line < 0) return data->line; @@ -333,6 +345,9 @@ static int dw8250_remove(struct platform_device *pdev) serial8250_unregister_port(data->line); + if (!IS_ERR(data->clk)) + clk_disable_unprepare(data->clk); + return 0; } |