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Commit 7fe090bf authored by Chen-Yu Tsai's avatar Chen-Yu Tsai Committed by Greg Kroah-Hartman
Browse files

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: default avatarChen-Yu Tsai <wens@csie.org>
Acked-by: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 1d6ba284

Documentation/devicetree/bindings/serial/snps-dw-apb-uart.txt

+1 −0
Original line number Original line Diff line number Diff line
@@ -15,6 +15,7 @@ The supplying peripheral clock can also be handled, needing a second property 
	Required elements: "baudclk", "apb_pclk"

	Required elements: "baudclk", "apb_pclk"





Optional properties:

Optional properties:

- resets : phandle to the parent reset controller.

- reg-shift : quantity to shift the register offsets by.  If this property is

- reg-shift : quantity to shift the register offsets by.  If this property is

  not present then the register offsets are not shifted.

  not present then the register offsets are not shifted.

- reg-io-width : the size (in bytes) of the IO accesses that should be

- reg-io-width : the size (in bytes) of the IO accesses that should be

drivers/tty/serial/8250/8250_dw.c

+9 −0
Original line number Original line Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include <linux/slab.h>

#include <linux/slab.h>

#include <linux/acpi.h>

#include <linux/acpi.h>

#include <linux/clk.h>

#include <linux/clk.h>

#include <linux/reset.h>

#include <linux/pm_runtime.h>

#include <linux/pm_runtime.h>





#include <asm/byteorder.h>

#include <asm/byteorder.h>
@@ -60,6 +61,7 @@ struct dw8250_data { 
	int			line;

	int			line;

	struct clk		*clk;

	struct clk		*clk;

	struct clk		*pclk;

	struct clk		*pclk;

	struct reset_control	*rst;

	struct uart_8250_dma	dma;

	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.rx_chan_id = -1;

	data->dma.tx_chan_id = -1;

	data->dma.tx_chan_id = -1;

	data->dma.rx_param = data;

	data->dma.rx_param = data;
@@ -426,6 +432,9 @@ static int dw8250_remove(struct platform_device *pdev) 




	serial8250_unregister_port(data->line);

	serial8250_unregister_port(data->line);





	if (!IS_ERR(data->rst))

		reset_control_assert(data->rst);



	if (!IS_ERR(data->pclk))

	if (!IS_ERR(data->pclk))

		clk_disable_unprepare(data->pclk);

		clk_disable_unprepare(data->pclk);