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Commit 2acb037f authored by Linus Walleij's avatar Linus Walleij Committed by Philipp Zabel
Browse files

reset: Add a Gemini reset controller 



The Cortina Systems Gemini reset controller is a simple
32bit register with self-deasserting reset lines. It is
accessed using regmap over syscon.

Acked-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
parent 12898791

drivers/reset/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -34,6 +34,13 @@ config RESET_BERLIN 
	help

	  This enables the reset controller driver for Marvell Berlin SoCs.



config RESET_GEMINI

	bool "Gemini Reset Driver" if COMPILE_TEST

	default ARCH_GEMINI

	select MFD_SYSCON

	help

	  This enables the reset controller driver for Cortina Systems Gemini.



config RESET_IMX7

	bool "i.MX7 Reset Driver" if COMPILE_TEST

	default SOC_IMX7D

drivers/reset/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ obj-$(CONFIG_ARCH_TEGRA) += tegra/ 
obj-$(CONFIG_RESET_A10SR) += reset-a10sr.o

obj-$(CONFIG_RESET_ATH79) += reset-ath79.o

obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o

obj-$(CONFIG_RESET_GEMINI) += reset-gemini.o

obj-$(CONFIG_RESET_IMX7) += reset-imx7.o

obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o

obj-$(CONFIG_RESET_MESON) += reset-meson.o

drivers/reset/reset-gemini.c

0 → 100644
+110 −0
Original line number Diff line number Diff line 
/*

 * Cortina Gemini Reset controller driver

 * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */



#include <linux/err.h>

#include <linux/init.h>

#include <linux/mfd/syscon.h>

#include <linux/regmap.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/reset-controller.h>

#include <dt-bindings/reset/cortina,gemini-reset.h>



/**

 * struct gemini_reset - gemini reset controller

 * @map: regmap to access the containing system controller

 * @rcdev: reset controller device

 */

struct gemini_reset {

	struct regmap *map;

	struct reset_controller_dev rcdev;

};



#define GEMINI_GLOBAL_SOFT_RESET 0x0c



#define to_gemini_reset(p) \

	container_of((p), struct gemini_reset, rcdev)



/*

 * This is a self-deasserting reset controller.

 */

static int gemini_reset(struct reset_controller_dev *rcdev,

			unsigned long id)

{

	struct gemini_reset *gr = to_gemini_reset(rcdev);



	/* Manual says to always set BIT 30 (CPU1) to 1 */

	return regmap_write(gr->map,

			    GEMINI_GLOBAL_SOFT_RESET,

			    BIT(GEMINI_RESET_CPU1) | BIT(id));

}



static int gemini_reset_status(struct reset_controller_dev *rcdev,

			     unsigned long id)

{

	struct gemini_reset *gr = to_gemini_reset(rcdev);

	u32 val;

	int ret;



	ret = regmap_read(gr->map, GEMINI_GLOBAL_SOFT_RESET, &val);

	if (ret)

		return ret;



	return !!(val & BIT(id));

}



static const struct reset_control_ops gemini_reset_ops = {

	.reset = gemini_reset,

	.status = gemini_reset_status,

};



static int gemini_reset_probe(struct platform_device *pdev)

{

	struct gemini_reset *gr;

	struct device *dev = &pdev->dev;

	struct device_node *np = dev->of_node;

	int ret;



	gr = devm_kzalloc(dev, sizeof(*gr), GFP_KERNEL);

	if (!gr)

		return -ENOMEM;



	gr->map = syscon_node_to_regmap(np);

	if (IS_ERR(gr->map)) {

		ret = PTR_ERR(gr->map);

		dev_err(dev, "unable to get regmap (%d)", ret);

		return ret;

	}

	gr->rcdev.owner = THIS_MODULE;

	gr->rcdev.nr_resets = 32;

	gr->rcdev.ops = &gemini_reset_ops;

	gr->rcdev.of_node = pdev->dev.of_node;



	ret = devm_reset_controller_register(&pdev->dev, &gr->rcdev);

	if (ret)

		return ret;



	dev_info(dev, "registered Gemini reset controller\n");

	return 0;

}



static const struct of_device_id gemini_reset_dt_ids[] = {

	{ .compatible = "cortina,gemini-syscon", },

	{ /* sentinel */ },

};



static struct platform_driver gemini_reset_driver = {

	.probe	= gemini_reset_probe,

	.driver = {

		.name		= "gemini-reset",

		.of_match_table	= gemini_reset_dt_ids,

		.suppress_bind_attrs = true,

	},

};

builtin_platform_driver(gemini_reset_driver);