1/*
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 int mb86s70_gpio_request(struct gpio_chip *gc, unsigned gpio)
48{
49 struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
50 unsigned long flags;
51 u32 val;
52
53 spin_lock_irqsave(&gchip->lock, flags);
54
55 val = readl(gchip->base + PFR(gpio));
56 val &= ~OFFSET(gpio);
57 writel(val, gchip->base + PFR(gpio));
58
59 spin_unlock_irqrestore(&gchip->lock, flags);
60
61 return 0;
62}
63
64static void mb86s70_gpio_free(struct gpio_chip *gc, unsigned gpio)
65{
66 struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
67 unsigned long flags;
68 u32 val;
69
70 spin_lock_irqsave(&gchip->lock, flags);
71
72 val = readl(gchip->base + PFR(gpio));
73 val |= OFFSET(gpio);
74 writel(val, gchip->base + PFR(gpio));
75
76 spin_unlock_irqrestore(&gchip->lock, flags);
77}
78
79static int mb86s70_gpio_direction_input(struct gpio_chip *gc, unsigned gpio)
80{
81 struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
82 unsigned long flags;
83 unsigned char val;
84
85 spin_lock_irqsave(&gchip->lock, flags);
86
87 val = readl(gchip->base + DDR(gpio));
88 val &= ~OFFSET(gpio);
89 writel(val, gchip->base + DDR(gpio));
90
91 spin_unlock_irqrestore(&gchip->lock, flags);
92
93 return 0;
94}
95
96static int mb86s70_gpio_direction_output(struct gpio_chip *gc,
97 unsigned gpio, int value)
98{
99 struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
100 unsigned long flags;
101 unsigned char val;
102
103 spin_lock_irqsave(&gchip->lock, flags);
104
105 val = readl(gchip->base + PDR(gpio));
106 if (value)
107 val |= OFFSET(gpio);
108 else
109 val &= ~OFFSET(gpio);
110 writel(val, gchip->base + PDR(gpio));
111
112 val = readl(gchip->base + DDR(gpio));
113 val |= OFFSET(gpio);
114 writel(val, gchip->base + DDR(gpio));
115
116 spin_unlock_irqrestore(&gchip->lock, flags);
117
118 return 0;
119}
120
121static int mb86s70_gpio_get(struct gpio_chip *gc, unsigned gpio)
122{
123 struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
124
125 return !!(readl(gchip->base + PDR(gpio)) & OFFSET(gpio));
126}
127
128static void mb86s70_gpio_set(struct gpio_chip *gc, unsigned gpio, int value)
129{
130 struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
131 unsigned long flags;
132 unsigned char val;
133
134 spin_lock_irqsave(&gchip->lock, flags);
135
136 val = readl(gchip->base + PDR(gpio));
137 if (value)
138 val |= OFFSET(gpio);
139 else
140 val &= ~OFFSET(gpio);
141 writel(val, gchip->base + PDR(gpio));
142
143 spin_unlock_irqrestore(&gchip->lock, flags);
144}
145
146static int mb86s70_gpio_probe(struct platform_device *pdev)
147{
148 struct mb86s70_gpio_chip *gchip;
149 struct resource *res;
150 int ret;
151
152 gchip = devm_kzalloc(&pdev->dev, sizeof(*gchip), GFP_KERNEL);
153 if (gchip == NULL)
154 return -ENOMEM;
155
156 platform_set_drvdata(pdev, gchip);
157
158 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
159 gchip->base = devm_ioremap_resource(&pdev->dev, res);
160 if (IS_ERR(gchip->base))
161 return PTR_ERR(gchip->base);
162
163 gchip->clk = devm_clk_get(&pdev->dev, NULL);
164 if (IS_ERR(gchip->clk))
165 return PTR_ERR(gchip->clk);
166
167 ret = clk_prepare_enable(gchip->clk);
168 if (ret)
169 return ret;
170
171 spin_lock_init(&gchip->lock);
172
173 gchip->gc.direction_output = mb86s70_gpio_direction_output;
174 gchip->gc.direction_input = mb86s70_gpio_direction_input;
175 gchip->gc.request = mb86s70_gpio_request;
176 gchip->gc.free = mb86s70_gpio_free;
177 gchip->gc.get = mb86s70_gpio_get;
178 gchip->gc.set = mb86s70_gpio_set;
179 gchip->gc.label = dev_name(&pdev->dev);
180 gchip->gc.ngpio = 32;
181 gchip->gc.owner = THIS_MODULE;
182 gchip->gc.parent = &pdev->dev;
183 gchip->gc.base = -1;
184
185 ret = gpiochip_add_data(&gchip->gc, gchip);
186 if (ret) {
187 dev_err(&pdev->dev, "couldn't register gpio driver\n");
188 clk_disable_unprepare(gchip->clk);
189 }
190
191 return ret;
192}
193
194static int mb86s70_gpio_remove(struct platform_device *pdev)
195{
196 struct mb86s70_gpio_chip *gchip = platform_get_drvdata(pdev);
197
198 gpiochip_remove(&gchip->gc);
199 clk_disable_unprepare(gchip->clk);
200
201 return 0;
202}
203
204static const struct of_device_id mb86s70_gpio_dt_ids[] = {
205 { .compatible = "fujitsu,mb86s70-gpio" },
206 { /* sentinel */ }
207};
208MODULE_DEVICE_TABLE(of, mb86s70_gpio_dt_ids);
209
210static struct platform_driver mb86s70_gpio_driver = {
211 .driver = {
212 .name = "mb86s70-gpio",
213 .of_match_table = mb86s70_gpio_dt_ids,
214 },
215 .probe = mb86s70_gpio_probe,
216 .remove = mb86s70_gpio_remove,
217};
218module_platform_driver(mb86s70_gpio_driver);
219
220MODULE_DESCRIPTION("MB86S7x GPIO Driver");
221MODULE_ALIAS("platform:mb86s70-gpio");
222MODULE_LICENSE("GPL");
223