mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-04 09:59:32 +00:00
![Linus Walleij](/assets/img/avatar_default.png)
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: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
110 lines
2.7 KiB
C
110 lines
2.7 KiB
C
/*
|
|
* 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);
|