diff options
| author | Chen-Yu Tsai <wens@csie.org> | 2014-07-23 19:33:06 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-07-27 22:07:07 +0400 |
| commit | 7fe090bf48b522de8cd6fe85e2b3252ed74e74f8 (patch) | |
| tree | bb5c2994d76becef318ec6e2bfbf125e6603db35 | |
| parent | 1d6ba284dff546baca58e78546da46be3b48462a (diff) | |
| download | linux-7fe090bf48b522de8cd6fe85e2b3252ed74e74f8.tar.xz | |
serial: 8250_dw: Add optional reset control support
The Allwinner A31 and A23 SoCs have a reset controller
maintaining the UART in reset by default.
This patch adds optional reset support to the driver.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | Documentation/devicetree/bindings/serial/snps-dw-apb-uart.txt | 1 | ||||
| -rw-r--r-- | drivers/tty/serial/8250/8250_dw.c | 9 |
2 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.txt b/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.txt index 095ac7172ffe..7f76214f728a 100644 --- a/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.txt +++ b/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.txt @@ -15,6 +15,7 @@ The supplying peripheral clock can also be handled, needing a second property Required elements: "baudclk", "apb_pclk" Optional properties: +- resets : phandle to the parent reset controller. - reg-shift : quantity to shift the register offsets by. If this property is not present then the register offsets are not shifted. - reg-io-width : the size (in bytes) of the IO accesses that should be diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index affdcb192aed..501db2f58fd2 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -26,6 +26,7 @@ #include <linux/slab.h> #include <linux/acpi.h> #include <linux/clk.h> +#include <linux/reset.h> #include <linux/pm_runtime.h> #include <asm/byteorder.h> @@ -60,6 +61,7 @@ struct dw8250_data { int line; struct clk *clk; struct clk *pclk; + struct reset_control *rst; struct uart_8250_dma dma; }; @@ -383,6 +385,10 @@ static int dw8250_probe(struct platform_device *pdev) } } + data->rst = devm_reset_control_get_optional(&pdev->dev, NULL); + if (!IS_ERR(data->rst)) + reset_control_deassert(data->rst); + data->dma.rx_chan_id = -1; data->dma.tx_chan_id = -1; data->dma.rx_param = data; @@ -426,6 +432,9 @@ static int dw8250_remove(struct platform_device *pdev) serial8250_unregister_port(data->line); + if (!IS_ERR(data->rst)) + reset_control_assert(data->rst); + if (!IS_ERR(data->pclk)) clk_disable_unprepare(data->pclk); |