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Jassi Brar0da094d2015-01-19 18:35:53 +08001/*
2 * linux/drivers/gpio/gpio-mb86s7x.c
3 *
4 * Copyright (C) 2015 Fujitsu Semiconductor Limited
5 * Copyright (C) 2015 Linaro Ltd.
6 *
7 * This program is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, version 2 of the License.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 */
16
17#include <linux/io.h>
18#include <linux/init.h>
19#include <linux/clk.h>
20#include <linux/module.h>
21#include <linux/err.h>
22#include <linux/errno.h>
23#include <linux/ioport.h>
24#include <linux/of_device.h>
25#include <linux/gpio/driver.h>
26#include <linux/platform_device.h>
27#include <linux/spinlock.h>
28#include <linux/slab.h>
29
30/*
31 * Only first 8bits of a register correspond to each pin,
32 * so there are 4 registers for 32 pins.
33 */
34#define PDR(x) (0x0 + x / 8 * 4)
35#define DDR(x) (0x10 + x / 8 * 4)
36#define PFR(x) (0x20 + x / 8 * 4)
37
38#define OFFSET(x) BIT((x) % 8)
39
40struct mb86s70_gpio_chip {
41 struct gpio_chip gc;
42 void __iomem *base;
43 struct clk *clk;
44 spinlock_t lock;
45};
46
47static inline struct mb86s70_gpio_chip *chip_to_mb86s70(struct gpio_chip *gc)
48{
49 return container_of(gc, struct mb86s70_gpio_chip, gc);
50}
51
52static int mb86s70_gpio_request(struct gpio_chip *gc, unsigned gpio)
53{
54 struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc);
55 unsigned long flags;
56 u32 val;
57
58 spin_lock_irqsave(&gchip->lock, flags);
59
60 val = readl(gchip->base + PFR(gpio));
Axel Linfd9c9632015-01-30 18:26:25 +080061 if (!(val & OFFSET(gpio))) {
62 spin_unlock_irqrestore(&gchip->lock, flags);
63 return -EINVAL;
64 }
65
Jassi Brar0da094d2015-01-19 18:35:53 +080066 val &= ~OFFSET(gpio);
67 writel(val, gchip->base + PFR(gpio));
68
69 spin_unlock_irqrestore(&gchip->lock, flags);
70
71 return 0;
72}
73
74static void mb86s70_gpio_free(struct gpio_chip *gc, unsigned gpio)
75{
76 struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc);
77 unsigned long flags;
78 u32 val;
79
80 spin_lock_irqsave(&gchip->lock, flags);
81
82 val = readl(gchip->base + PFR(gpio));
83 val |= OFFSET(gpio);
84 writel(val, gchip->base + PFR(gpio));
85
86 spin_unlock_irqrestore(&gchip->lock, flags);
87}
88
89static int mb86s70_gpio_direction_input(struct gpio_chip *gc, unsigned gpio)
90{
91 struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc);
92 unsigned long flags;
93 unsigned char val;
94
95 spin_lock_irqsave(&gchip->lock, flags);
96
97 val = readl(gchip->base + DDR(gpio));
98 val &= ~OFFSET(gpio);
99 writel(val, gchip->base + DDR(gpio));
100
101 spin_unlock_irqrestore(&gchip->lock, flags);
102
103 return 0;
104}
105
106static int mb86s70_gpio_direction_output(struct gpio_chip *gc,
107 unsigned gpio, int value)
108{
109 struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc);
110 unsigned long flags;
111 unsigned char val;
112
113 spin_lock_irqsave(&gchip->lock, flags);
114
115 val = readl(gchip->base + PDR(gpio));
116 if (value)
117 val |= OFFSET(gpio);
118 else
119 val &= ~OFFSET(gpio);
120 writel(val, gchip->base + PDR(gpio));
121
122 val = readl(gchip->base + DDR(gpio));
123 val |= OFFSET(gpio);
124 writel(val, gchip->base + DDR(gpio));
125
126 spin_unlock_irqrestore(&gchip->lock, flags);
127
128 return 0;
129}
130
131static int mb86s70_gpio_get(struct gpio_chip *gc, unsigned gpio)
132{
133 struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc);
134
135 return !!(readl(gchip->base + PDR(gpio)) & OFFSET(gpio));
136}
137
138static void mb86s70_gpio_set(struct gpio_chip *gc, unsigned gpio, int value)
139{
140 struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc);
141 unsigned long flags;
142 unsigned char val;
143
144 spin_lock_irqsave(&gchip->lock, flags);
145
146 val = readl(gchip->base + PDR(gpio));
147 if (value)
148 val |= OFFSET(gpio);
149 else
150 val &= ~OFFSET(gpio);
151 writel(val, gchip->base + PDR(gpio));
152
153 spin_unlock_irqrestore(&gchip->lock, flags);
154}
155
156static int mb86s70_gpio_probe(struct platform_device *pdev)
157{
158 struct mb86s70_gpio_chip *gchip;
159 struct resource *res;
160 int ret;
161
162 gchip = devm_kzalloc(&pdev->dev, sizeof(*gchip), GFP_KERNEL);
163 if (gchip == NULL)
164 return -ENOMEM;
165
166 platform_set_drvdata(pdev, gchip);
167
168 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
169 gchip->base = devm_ioremap_resource(&pdev->dev, res);
170 if (IS_ERR(gchip->base))
171 return PTR_ERR(gchip->base);
172
173 gchip->clk = devm_clk_get(&pdev->dev, NULL);
174 if (IS_ERR(gchip->clk))
175 return PTR_ERR(gchip->clk);
176
177 clk_prepare_enable(gchip->clk);
178
179 spin_lock_init(&gchip->lock);
180
181 gchip->gc.direction_output = mb86s70_gpio_direction_output;
182 gchip->gc.direction_input = mb86s70_gpio_direction_input;
183 gchip->gc.request = mb86s70_gpio_request;
184 gchip->gc.free = mb86s70_gpio_free;
185 gchip->gc.get = mb86s70_gpio_get;
186 gchip->gc.set = mb86s70_gpio_set;
187 gchip->gc.label = dev_name(&pdev->dev);
188 gchip->gc.ngpio = 32;
189 gchip->gc.owner = THIS_MODULE;
190 gchip->gc.dev = &pdev->dev;
191 gchip->gc.base = -1;
192
193 platform_set_drvdata(pdev, gchip);
194
195 ret = gpiochip_add(&gchip->gc);
196 if (ret) {
197 dev_err(&pdev->dev, "couldn't register gpio driver\n");
198 clk_disable_unprepare(gchip->clk);
199 }
200
201 return ret;
202}
203
204static int mb86s70_gpio_remove(struct platform_device *pdev)
205{
206 struct mb86s70_gpio_chip *gchip = platform_get_drvdata(pdev);
207
208 gpiochip_remove(&gchip->gc);
209 clk_disable_unprepare(gchip->clk);
210
211 return 0;
212}
213
214static const struct of_device_id mb86s70_gpio_dt_ids[] = {
215 { .compatible = "fujitsu,mb86s70-gpio" },
216 { /* sentinel */ }
217};
218MODULE_DEVICE_TABLE(of, mb86s70_gpio_dt_ids);
219
220static struct platform_driver mb86s70_gpio_driver = {
221 .driver = {
222 .name = "mb86s70-gpio",
223 .of_match_table = mb86s70_gpio_dt_ids,
224 },
225 .probe = mb86s70_gpio_probe,
226 .remove = mb86s70_gpio_remove,
227};
228
229static int __init mb86s70_gpio_init(void)
230{
231 return platform_driver_register(&mb86s70_gpio_driver);
232}
233module_init(mb86s70_gpio_init);
234
235MODULE_DESCRIPTION("MB86S7x GPIO Driver");
236MODULE_ALIAS("platform:mb86s70-gpio");
237MODULE_LICENSE("GPL");