File: gpio-mb86s7x.c

package info (click to toggle)
linux 4.19.20-1
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 954,852 kB
  • sloc: ansic: 16,749,828; asm: 271,286; makefile: 38,257; sh: 32,808; perl: 27,671; python: 21,022; cpp: 5,063; yacc: 4,648; lex: 2,585; awk: 1,385; ruby: 25; sed: 5
file content (222 lines) | stat: -rw-r--r-- 5,481 bytes parent folder | download | duplicates (7)
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
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
/*
 *  linux/drivers/gpio/gpio-mb86s7x.c
 *
 *  Copyright (C) 2015 Fujitsu Semiconductor Limited
 *  Copyright (C) 2015 Linaro Ltd.
 *
 *  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, version 2 of the License.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 */

#include <linux/io.h>
#include <linux/init.h>
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/of_device.h>
#include <linux/gpio/driver.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/slab.h>

/*
 * Only first 8bits of a register correspond to each pin,
 * so there are 4 registers for 32 pins.
 */
#define PDR(x)	(0x0 + x / 8 * 4)
#define DDR(x)	(0x10 + x / 8 * 4)
#define PFR(x)	(0x20 + x / 8 * 4)

#define OFFSET(x)	BIT((x) % 8)

struct mb86s70_gpio_chip {
	struct gpio_chip gc;
	void __iomem *base;
	struct clk *clk;
	spinlock_t lock;
};

static int mb86s70_gpio_request(struct gpio_chip *gc, unsigned gpio)
{
	struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
	unsigned long flags;
	u32 val;

	spin_lock_irqsave(&gchip->lock, flags);

	val = readl(gchip->base + PFR(gpio));
	val &= ~OFFSET(gpio);
	writel(val, gchip->base + PFR(gpio));

	spin_unlock_irqrestore(&gchip->lock, flags);

	return 0;
}

static void mb86s70_gpio_free(struct gpio_chip *gc, unsigned gpio)
{
	struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
	unsigned long flags;
	u32 val;

	spin_lock_irqsave(&gchip->lock, flags);

	val = readl(gchip->base + PFR(gpio));
	val |= OFFSET(gpio);
	writel(val, gchip->base + PFR(gpio));

	spin_unlock_irqrestore(&gchip->lock, flags);
}

static int mb86s70_gpio_direction_input(struct gpio_chip *gc, unsigned gpio)
{
	struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
	unsigned long flags;
	unsigned char val;

	spin_lock_irqsave(&gchip->lock, flags);

	val = readl(gchip->base + DDR(gpio));
	val &= ~OFFSET(gpio);
	writel(val, gchip->base + DDR(gpio));

	spin_unlock_irqrestore(&gchip->lock, flags);

	return 0;
}

static int mb86s70_gpio_direction_output(struct gpio_chip *gc,
					 unsigned gpio, int value)
{
	struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
	unsigned long flags;
	unsigned char val;

	spin_lock_irqsave(&gchip->lock, flags);

	val = readl(gchip->base + PDR(gpio));
	if (value)
		val |= OFFSET(gpio);
	else
		val &= ~OFFSET(gpio);
	writel(val, gchip->base + PDR(gpio));

	val = readl(gchip->base + DDR(gpio));
	val |= OFFSET(gpio);
	writel(val, gchip->base + DDR(gpio));

	spin_unlock_irqrestore(&gchip->lock, flags);

	return 0;
}

static int mb86s70_gpio_get(struct gpio_chip *gc, unsigned gpio)
{
	struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);

	return !!(readl(gchip->base + PDR(gpio)) & OFFSET(gpio));
}

static void mb86s70_gpio_set(struct gpio_chip *gc, unsigned gpio, int value)
{
	struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
	unsigned long flags;
	unsigned char val;

	spin_lock_irqsave(&gchip->lock, flags);

	val = readl(gchip->base + PDR(gpio));
	if (value)
		val |= OFFSET(gpio);
	else
		val &= ~OFFSET(gpio);
	writel(val, gchip->base + PDR(gpio));

	spin_unlock_irqrestore(&gchip->lock, flags);
}

static int mb86s70_gpio_probe(struct platform_device *pdev)
{
	struct mb86s70_gpio_chip *gchip;
	struct resource *res;
	int ret;

	gchip = devm_kzalloc(&pdev->dev, sizeof(*gchip), GFP_KERNEL);
	if (gchip == NULL)
		return -ENOMEM;

	platform_set_drvdata(pdev, gchip);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	gchip->base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(gchip->base))
		return PTR_ERR(gchip->base);

	gchip->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(gchip->clk))
		return PTR_ERR(gchip->clk);

	ret = clk_prepare_enable(gchip->clk);
	if (ret)
		return ret;

	spin_lock_init(&gchip->lock);

	gchip->gc.direction_output = mb86s70_gpio_direction_output;
	gchip->gc.direction_input = mb86s70_gpio_direction_input;
	gchip->gc.request = mb86s70_gpio_request;
	gchip->gc.free = mb86s70_gpio_free;
	gchip->gc.get = mb86s70_gpio_get;
	gchip->gc.set = mb86s70_gpio_set;
	gchip->gc.label = dev_name(&pdev->dev);
	gchip->gc.ngpio = 32;
	gchip->gc.owner = THIS_MODULE;
	gchip->gc.parent = &pdev->dev;
	gchip->gc.base = -1;

	ret = gpiochip_add_data(&gchip->gc, gchip);
	if (ret) {
		dev_err(&pdev->dev, "couldn't register gpio driver\n");
		clk_disable_unprepare(gchip->clk);
	}

	return ret;
}

static int mb86s70_gpio_remove(struct platform_device *pdev)
{
	struct mb86s70_gpio_chip *gchip = platform_get_drvdata(pdev);

	gpiochip_remove(&gchip->gc);
	clk_disable_unprepare(gchip->clk);

	return 0;
}

static const struct of_device_id mb86s70_gpio_dt_ids[] = {
	{ .compatible = "fujitsu,mb86s70-gpio" },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mb86s70_gpio_dt_ids);

static struct platform_driver mb86s70_gpio_driver = {
	.driver = {
		.name = "mb86s70-gpio",
		.of_match_table = mb86s70_gpio_dt_ids,
	},
	.probe = mb86s70_gpio_probe,
	.remove = mb86s70_gpio_remove,
};
module_platform_driver(mb86s70_gpio_driver);

MODULE_DESCRIPTION("MB86S7x GPIO Driver");
MODULE_ALIAS("platform:mb86s70-gpio");
MODULE_LICENSE("GPL");