Version:  2.0.40 2.2.26 2.4.37 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17

Linux/drivers/reset/reset-sunxi.c

  1 /*
  2  * Allwinner SoCs Reset Controller driver
  3  *
  4  * Copyright 2013 Maxime Ripard
  5  *
  6  * Maxime Ripard <maxime.ripard@free-electrons.com>
  7  *
  8  * This program is free software; you can redistribute it and/or modify
  9  * it under the terms of the GNU General Public License as published by
 10  * the Free Software Foundation; either version 2 of the License, or
 11  * (at your option) any later version.
 12  */
 13 
 14 #include <linux/err.h>
 15 #include <linux/io.h>
 16 #include <linux/module.h>
 17 #include <linux/of.h>
 18 #include <linux/of_address.h>
 19 #include <linux/platform_device.h>
 20 #include <linux/reset-controller.h>
 21 #include <linux/slab.h>
 22 #include <linux/spinlock.h>
 23 #include <linux/types.h>
 24 
 25 struct sunxi_reset_data {
 26         spinlock_t                      lock;
 27         void __iomem                    *membase;
 28         struct reset_controller_dev     rcdev;
 29 };
 30 
 31 static int sunxi_reset_assert(struct reset_controller_dev *rcdev,
 32                               unsigned long id)
 33 {
 34         struct sunxi_reset_data *data = container_of(rcdev,
 35                                                      struct sunxi_reset_data,
 36                                                      rcdev);
 37         int bank = id / BITS_PER_LONG;
 38         int offset = id % BITS_PER_LONG;
 39         unsigned long flags;
 40         u32 reg;
 41 
 42         spin_lock_irqsave(&data->lock, flags);
 43 
 44         reg = readl(data->membase + (bank * 4));
 45         writel(reg & ~BIT(offset), data->membase + (bank * 4));
 46 
 47         spin_unlock_irqrestore(&data->lock, flags);
 48 
 49         return 0;
 50 }
 51 
 52 static int sunxi_reset_deassert(struct reset_controller_dev *rcdev,
 53                                 unsigned long id)
 54 {
 55         struct sunxi_reset_data *data = container_of(rcdev,
 56                                                      struct sunxi_reset_data,
 57                                                      rcdev);
 58         int bank = id / BITS_PER_LONG;
 59         int offset = id % BITS_PER_LONG;
 60         unsigned long flags;
 61         u32 reg;
 62 
 63         spin_lock_irqsave(&data->lock, flags);
 64 
 65         reg = readl(data->membase + (bank * 4));
 66         writel(reg | BIT(offset), data->membase + (bank * 4));
 67 
 68         spin_unlock_irqrestore(&data->lock, flags);
 69 
 70         return 0;
 71 }
 72 
 73 static struct reset_control_ops sunxi_reset_ops = {
 74         .assert         = sunxi_reset_assert,
 75         .deassert       = sunxi_reset_deassert,
 76 };
 77 
 78 static int sunxi_reset_init(struct device_node *np)
 79 {
 80         struct sunxi_reset_data *data;
 81         struct resource res;
 82         resource_size_t size;
 83         int ret;
 84 
 85         data = kzalloc(sizeof(*data), GFP_KERNEL);
 86         if (!data)
 87                 return -ENOMEM;
 88 
 89         ret = of_address_to_resource(np, 0, &res);
 90         if (ret)
 91                 goto err_alloc;
 92 
 93         size = resource_size(&res);
 94         if (!request_mem_region(res.start, size, np->name)) {
 95                 ret = -EBUSY;
 96                 goto err_alloc;
 97         }
 98 
 99         data->membase = ioremap(res.start, size);
100         if (!data->membase) {
101                 ret = -ENOMEM;
102                 goto err_alloc;
103         }
104 
105         data->rcdev.owner = THIS_MODULE;
106         data->rcdev.nr_resets = size * 32;
107         data->rcdev.ops = &sunxi_reset_ops;
108         data->rcdev.of_node = np;
109         reset_controller_register(&data->rcdev);
110 
111         return 0;
112 
113 err_alloc:
114         kfree(data);
115         return ret;
116 };
117 
118 /*
119  * These are the reset controller we need to initialize early on in
120  * our system, before we can even think of using a regular device
121  * driver for it.
122  */
123 static const struct of_device_id sunxi_early_reset_dt_ids[] __initdata = {
124         { .compatible = "allwinner,sun6i-a31-ahb1-reset", },
125         { /* sentinel */ },
126 };
127 
128 void __init sun6i_reset_init(void)
129 {
130         struct device_node *np;
131 
132         for_each_matching_node(np, sunxi_early_reset_dt_ids)
133                 sunxi_reset_init(np);
134 }
135 
136 /*
137  * And these are the controllers we can register through the regular
138  * device model.
139  */
140 static const struct of_device_id sunxi_reset_dt_ids[] = {
141          { .compatible = "allwinner,sun6i-a31-clock-reset", },
142          { /* sentinel */ },
143 };
144 MODULE_DEVICE_TABLE(of, sunxi_reset_dt_ids);
145 
146 static int sunxi_reset_probe(struct platform_device *pdev)
147 {
148         struct sunxi_reset_data *data;
149         struct resource *res;
150 
151         data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
152         if (!data)
153                 return -ENOMEM;
154 
155         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
156         data->membase = devm_ioremap_resource(&pdev->dev, res);
157         if (IS_ERR(data->membase))
158                 return PTR_ERR(data->membase);
159 
160         data->rcdev.owner = THIS_MODULE;
161         data->rcdev.nr_resets = resource_size(res) * 32;
162         data->rcdev.ops = &sunxi_reset_ops;
163         data->rcdev.of_node = pdev->dev.of_node;
164 
165         return reset_controller_register(&data->rcdev);
166 }
167 
168 static int sunxi_reset_remove(struct platform_device *pdev)
169 {
170         struct sunxi_reset_data *data = platform_get_drvdata(pdev);
171 
172         reset_controller_unregister(&data->rcdev);
173 
174         return 0;
175 }
176 
177 static struct platform_driver sunxi_reset_driver = {
178         .probe  = sunxi_reset_probe,
179         .remove = sunxi_reset_remove,
180         .driver = {
181                 .name           = "sunxi-reset",
182                 .owner          = THIS_MODULE,
183                 .of_match_table = sunxi_reset_dt_ids,
184         },
185 };
186 module_platform_driver(sunxi_reset_driver);
187 
188 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com");
189 MODULE_DESCRIPTION("Allwinner SoCs Reset Controller Driver");
190 MODULE_LICENSE("GPL");
191 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us