xref: /openbmc/linux/drivers/gpio/gpio-mb86s7x.c (revision 92a2c6b2)
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 
40 struct mb86s70_gpio_chip {
41 	struct gpio_chip gc;
42 	void __iomem *base;
43 	struct clk *clk;
44 	spinlock_t lock;
45 };
46 
47 static 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 
52 static 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));
61 	val &= ~OFFSET(gpio);
62 	writel(val, gchip->base + PFR(gpio));
63 
64 	spin_unlock_irqrestore(&gchip->lock, flags);
65 
66 	return 0;
67 }
68 
69 static void mb86s70_gpio_free(struct gpio_chip *gc, unsigned gpio)
70 {
71 	struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc);
72 	unsigned long flags;
73 	u32 val;
74 
75 	spin_lock_irqsave(&gchip->lock, flags);
76 
77 	val = readl(gchip->base + PFR(gpio));
78 	val |= OFFSET(gpio);
79 	writel(val, gchip->base + PFR(gpio));
80 
81 	spin_unlock_irqrestore(&gchip->lock, flags);
82 }
83 
84 static int mb86s70_gpio_direction_input(struct gpio_chip *gc, unsigned gpio)
85 {
86 	struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc);
87 	unsigned long flags;
88 	unsigned char val;
89 
90 	spin_lock_irqsave(&gchip->lock, flags);
91 
92 	val = readl(gchip->base + DDR(gpio));
93 	val &= ~OFFSET(gpio);
94 	writel(val, gchip->base + DDR(gpio));
95 
96 	spin_unlock_irqrestore(&gchip->lock, flags);
97 
98 	return 0;
99 }
100 
101 static int mb86s70_gpio_direction_output(struct gpio_chip *gc,
102 					 unsigned gpio, int value)
103 {
104 	struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc);
105 	unsigned long flags;
106 	unsigned char val;
107 
108 	spin_lock_irqsave(&gchip->lock, flags);
109 
110 	val = readl(gchip->base + PDR(gpio));
111 	if (value)
112 		val |= OFFSET(gpio);
113 	else
114 		val &= ~OFFSET(gpio);
115 	writel(val, gchip->base + PDR(gpio));
116 
117 	val = readl(gchip->base + DDR(gpio));
118 	val |= OFFSET(gpio);
119 	writel(val, gchip->base + DDR(gpio));
120 
121 	spin_unlock_irqrestore(&gchip->lock, flags);
122 
123 	return 0;
124 }
125 
126 static int mb86s70_gpio_get(struct gpio_chip *gc, unsigned gpio)
127 {
128 	struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc);
129 
130 	return !!(readl(gchip->base + PDR(gpio)) & OFFSET(gpio));
131 }
132 
133 static void mb86s70_gpio_set(struct gpio_chip *gc, unsigned gpio, int value)
134 {
135 	struct mb86s70_gpio_chip *gchip = chip_to_mb86s70(gc);
136 	unsigned long flags;
137 	unsigned char val;
138 
139 	spin_lock_irqsave(&gchip->lock, flags);
140 
141 	val = readl(gchip->base + PDR(gpio));
142 	if (value)
143 		val |= OFFSET(gpio);
144 	else
145 		val &= ~OFFSET(gpio);
146 	writel(val, gchip->base + PDR(gpio));
147 
148 	spin_unlock_irqrestore(&gchip->lock, flags);
149 }
150 
151 static int mb86s70_gpio_probe(struct platform_device *pdev)
152 {
153 	struct mb86s70_gpio_chip *gchip;
154 	struct resource *res;
155 	int ret;
156 
157 	gchip = devm_kzalloc(&pdev->dev, sizeof(*gchip), GFP_KERNEL);
158 	if (gchip == NULL)
159 		return -ENOMEM;
160 
161 	platform_set_drvdata(pdev, gchip);
162 
163 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
164 	gchip->base = devm_ioremap_resource(&pdev->dev, res);
165 	if (IS_ERR(gchip->base))
166 		return PTR_ERR(gchip->base);
167 
168 	gchip->clk = devm_clk_get(&pdev->dev, NULL);
169 	if (IS_ERR(gchip->clk))
170 		return PTR_ERR(gchip->clk);
171 
172 	clk_prepare_enable(gchip->clk);
173 
174 	spin_lock_init(&gchip->lock);
175 
176 	gchip->gc.direction_output = mb86s70_gpio_direction_output;
177 	gchip->gc.direction_input = mb86s70_gpio_direction_input;
178 	gchip->gc.request = mb86s70_gpio_request;
179 	gchip->gc.free = mb86s70_gpio_free;
180 	gchip->gc.get = mb86s70_gpio_get;
181 	gchip->gc.set = mb86s70_gpio_set;
182 	gchip->gc.label = dev_name(&pdev->dev);
183 	gchip->gc.ngpio = 32;
184 	gchip->gc.owner = THIS_MODULE;
185 	gchip->gc.dev = &pdev->dev;
186 	gchip->gc.base = -1;
187 
188 	platform_set_drvdata(pdev, gchip);
189 
190 	ret = gpiochip_add(&gchip->gc);
191 	if (ret) {
192 		dev_err(&pdev->dev, "couldn't register gpio driver\n");
193 		clk_disable_unprepare(gchip->clk);
194 	}
195 
196 	return ret;
197 }
198 
199 static int mb86s70_gpio_remove(struct platform_device *pdev)
200 {
201 	struct mb86s70_gpio_chip *gchip = platform_get_drvdata(pdev);
202 
203 	gpiochip_remove(&gchip->gc);
204 	clk_disable_unprepare(gchip->clk);
205 
206 	return 0;
207 }
208 
209 static const struct of_device_id mb86s70_gpio_dt_ids[] = {
210 	{ .compatible = "fujitsu,mb86s70-gpio" },
211 	{ /* sentinel */ }
212 };
213 MODULE_DEVICE_TABLE(of, mb86s70_gpio_dt_ids);
214 
215 static struct platform_driver mb86s70_gpio_driver = {
216 	.driver = {
217 		.name = "mb86s70-gpio",
218 		.of_match_table = mb86s70_gpio_dt_ids,
219 	},
220 	.probe = mb86s70_gpio_probe,
221 	.remove = mb86s70_gpio_remove,
222 };
223 
224 static int __init mb86s70_gpio_init(void)
225 {
226 	return platform_driver_register(&mb86s70_gpio_driver);
227 }
228 module_init(mb86s70_gpio_init);
229 
230 MODULE_DESCRIPTION("MB86S7x GPIO Driver");
231 MODULE_ALIAS("platform:mb86s70-gpio");
232 MODULE_LICENSE("GPL");
233