Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 | /*
* Allwinner SoCs Reset Controller driver
*
* Copyright 2013 Maxime Ripard
*
* Maxime Ripard <maxime.ripard@free-electrons.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/err.h>
#include <linux/io.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/reset-controller.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/types.h>
struct sunxi_reset_data {
spinlock_t lock;
void __iomem *membase;
struct reset_controller_dev rcdev;
};
static int sunxi_reset_assert(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct sunxi_reset_data *data = container_of(rcdev,
struct sunxi_reset_data,
rcdev);
int reg_width = sizeof(u32);
int bank = id / (reg_width * BITS_PER_BYTE);
int offset = id % (reg_width * BITS_PER_BYTE);
unsigned long flags;
u32 reg;
spin_lock_irqsave(&data->lock, flags);
reg = readl(data->membase + (bank * reg_width));
writel(reg & ~BIT(offset), data->membase + (bank * reg_width));
spin_unlock_irqrestore(&data->lock, flags);
return 0;
}
static int sunxi_reset_deassert(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct sunxi_reset_data *data = container_of(rcdev,
struct sunxi_reset_data,
rcdev);
int reg_width = sizeof(u32);
int bank = id / (reg_width * BITS_PER_BYTE);
int offset = id % (reg_width * BITS_PER_BYTE);
unsigned long flags;
u32 reg;
spin_lock_irqsave(&data->lock, flags);
reg = readl(data->membase + (bank * reg_width));
writel(reg | BIT(offset), data->membase + (bank * reg_width));
spin_unlock_irqrestore(&data->lock, flags);
return 0;
}
static const struct reset_control_ops sunxi_reset_ops = {
.assert = sunxi_reset_assert,
.deassert = sunxi_reset_deassert,
};
static int sunxi_reset_init(struct device_node *np)
{
struct sunxi_reset_data *data;
struct resource res;
resource_size_t size;
int ret;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
ret = of_address_to_resource(np, 0, &res);
if (ret)
goto err_alloc;
size = resource_size(&res);
if (!request_mem_region(res.start, size, np->name)) {
ret = -EBUSY;
goto err_alloc;
}
data->membase = ioremap(res.start, size);
if (!data->membase) {
ret = -ENOMEM;
goto err_alloc;
}
spin_lock_init(&data->lock);
data->rcdev.owner = THIS_MODULE;
data->rcdev.nr_resets = size * 8;
data->rcdev.ops = &sunxi_reset_ops;
data->rcdev.of_node = np;
return reset_controller_register(&data->rcdev);
err_alloc:
kfree(data);
return ret;
};
/*
* These are the reset controller we need to initialize early on in
* our system, before we can even think of using a regular device
* driver for it.
*/
static const struct of_device_id sunxi_early_reset_dt_ids[] __initconst = {
{ .compatible = "allwinner,sun6i-a31-ahb1-reset", },
{ /* sentinel */ },
};
void __init sun6i_reset_init(void)
{
struct device_node *np;
for_each_matching_node(np, sunxi_early_reset_dt_ids)
sunxi_reset_init(np);
}
/*
* And these are the controllers we can register through the regular
* device model.
*/
static const struct of_device_id sunxi_reset_dt_ids[] = {
{ .compatible = "allwinner,sun6i-a31-clock-reset", },
{ /* sentinel */ },
};
static int sunxi_reset_probe(struct platform_device *pdev)
{
struct sunxi_reset_data *data;
struct resource *res;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
data->membase = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(data->membase))
return PTR_ERR(data->membase);
spin_lock_init(&data->lock);
data->rcdev.owner = THIS_MODULE;
data->rcdev.nr_resets = resource_size(res) * 8;
data->rcdev.ops = &sunxi_reset_ops;
data->rcdev.of_node = pdev->dev.of_node;
return devm_reset_controller_register(&pdev->dev, &data->rcdev);
}
static struct platform_driver sunxi_reset_driver = {
.probe = sunxi_reset_probe,
.driver = {
.name = "sunxi-reset",
.of_match_table = sunxi_reset_dt_ids,
},
};
builtin_platform_driver(sunxi_reset_driver);
|