File: gpio-xgene.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 (241 lines) | stat: -rw-r--r-- 6,494 bytes parent folder | download | duplicates (10)
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
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
/*
 * AppliedMicro X-Gene SoC GPIO Driver
 *
 * Copyright (c) 2014, Applied Micro Circuits Corporation
 * Author: Feng Kan <fkan@apm.com>.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/acpi.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/gpio/driver.h>
#include <linux/types.h>
#include <linux/bitops.h>

#define GPIO_SET_DR_OFFSET	0x0C
#define GPIO_DATA_OFFSET	0x14
#define GPIO_BANK_STRIDE	0x0C

#define XGENE_GPIOS_PER_BANK	16
#define XGENE_MAX_GPIO_BANKS	3
#define XGENE_MAX_GPIOS		(XGENE_GPIOS_PER_BANK * XGENE_MAX_GPIO_BANKS)

#define GPIO_BIT_OFFSET(x)	(x % XGENE_GPIOS_PER_BANK)
#define GPIO_BANK_OFFSET(x)	((x / XGENE_GPIOS_PER_BANK) * GPIO_BANK_STRIDE)

struct xgene_gpio {
	struct gpio_chip	chip;
	void __iomem		*base;
	spinlock_t		lock;
	u32			set_dr_val[XGENE_MAX_GPIO_BANKS];
};

static int xgene_gpio_get(struct gpio_chip *gc, unsigned int offset)
{
	struct xgene_gpio *chip = gpiochip_get_data(gc);
	unsigned long bank_offset;
	u32 bit_offset;

	bank_offset = GPIO_DATA_OFFSET + GPIO_BANK_OFFSET(offset);
	bit_offset = GPIO_BIT_OFFSET(offset);
	return !!(ioread32(chip->base + bank_offset) & BIT(bit_offset));
}

static void __xgene_gpio_set(struct gpio_chip *gc, unsigned int offset, int val)
{
	struct xgene_gpio *chip = gpiochip_get_data(gc);
	unsigned long bank_offset;
	u32 setval, bit_offset;

	bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
	bit_offset = GPIO_BIT_OFFSET(offset) + XGENE_GPIOS_PER_BANK;

	setval = ioread32(chip->base + bank_offset);
	if (val)
		setval |= BIT(bit_offset);
	else
		setval &= ~BIT(bit_offset);
	iowrite32(setval, chip->base + bank_offset);
}

static void xgene_gpio_set(struct gpio_chip *gc, unsigned int offset, int val)
{
	struct xgene_gpio *chip = gpiochip_get_data(gc);
	unsigned long flags;

	spin_lock_irqsave(&chip->lock, flags);
	__xgene_gpio_set(gc, offset, val);
	spin_unlock_irqrestore(&chip->lock, flags);
}

static int xgene_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
{
	struct xgene_gpio *chip = gpiochip_get_data(gc);
	unsigned long bank_offset, bit_offset;

	bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
	bit_offset = GPIO_BIT_OFFSET(offset);

	return !!(ioread32(chip->base + bank_offset) & BIT(bit_offset));
}

static int xgene_gpio_dir_in(struct gpio_chip *gc, unsigned int offset)
{
	struct xgene_gpio *chip = gpiochip_get_data(gc);
	unsigned long flags, bank_offset;
	u32 dirval, bit_offset;

	bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
	bit_offset = GPIO_BIT_OFFSET(offset);

	spin_lock_irqsave(&chip->lock, flags);

	dirval = ioread32(chip->base + bank_offset);
	dirval |= BIT(bit_offset);
	iowrite32(dirval, chip->base + bank_offset);

	spin_unlock_irqrestore(&chip->lock, flags);

	return 0;
}

static int xgene_gpio_dir_out(struct gpio_chip *gc,
					unsigned int offset, int val)
{
	struct xgene_gpio *chip = gpiochip_get_data(gc);
	unsigned long flags, bank_offset;
	u32 dirval, bit_offset;

	bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
	bit_offset = GPIO_BIT_OFFSET(offset);

	spin_lock_irqsave(&chip->lock, flags);

	dirval = ioread32(chip->base + bank_offset);
	dirval &= ~BIT(bit_offset);
	iowrite32(dirval, chip->base + bank_offset);
	__xgene_gpio_set(gc, offset, val);

	spin_unlock_irqrestore(&chip->lock, flags);

	return 0;
}

static __maybe_unused int xgene_gpio_suspend(struct device *dev)
{
	struct xgene_gpio *gpio = dev_get_drvdata(dev);
	unsigned long bank_offset;
	unsigned int bank;

	for (bank = 0; bank < XGENE_MAX_GPIO_BANKS; bank++) {
		bank_offset = GPIO_SET_DR_OFFSET + bank * GPIO_BANK_STRIDE;
		gpio->set_dr_val[bank] = ioread32(gpio->base + bank_offset);
	}
	return 0;
}

static __maybe_unused int xgene_gpio_resume(struct device *dev)
{
	struct xgene_gpio *gpio = dev_get_drvdata(dev);
	unsigned long bank_offset;
	unsigned int bank;

	for (bank = 0; bank < XGENE_MAX_GPIO_BANKS; bank++) {
		bank_offset = GPIO_SET_DR_OFFSET + bank * GPIO_BANK_STRIDE;
		iowrite32(gpio->set_dr_val[bank], gpio->base + bank_offset);
	}
	return 0;
}

static SIMPLE_DEV_PM_OPS(xgene_gpio_pm, xgene_gpio_suspend, xgene_gpio_resume);

static int xgene_gpio_probe(struct platform_device *pdev)
{
	struct resource *res;
	struct xgene_gpio *gpio;
	int err = 0;

	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
	if (!gpio) {
		err = -ENOMEM;
		goto err;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		err = -EINVAL;
		goto err;
	}

	gpio->base = devm_ioremap_nocache(&pdev->dev, res->start,
							resource_size(res));
	if (!gpio->base) {
		err = -ENOMEM;
		goto err;
	}

	gpio->chip.ngpio = XGENE_MAX_GPIOS;

	spin_lock_init(&gpio->lock);
	gpio->chip.parent = &pdev->dev;
	gpio->chip.get_direction = xgene_gpio_get_direction;
	gpio->chip.direction_input = xgene_gpio_dir_in;
	gpio->chip.direction_output = xgene_gpio_dir_out;
	gpio->chip.get = xgene_gpio_get;
	gpio->chip.set = xgene_gpio_set;
	gpio->chip.label = dev_name(&pdev->dev);
	gpio->chip.base = -1;

	platform_set_drvdata(pdev, gpio);

	err = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
	if (err) {
		dev_err(&pdev->dev,
			"failed to register gpiochip.\n");
		goto err;
	}

	dev_info(&pdev->dev, "X-Gene GPIO driver registered.\n");
	return 0;
err:
	dev_err(&pdev->dev, "X-Gene GPIO driver registration failed.\n");
	return err;
}

static const struct of_device_id xgene_gpio_of_match[] = {
	{ .compatible = "apm,xgene-gpio", },
	{},
};

#ifdef CONFIG_ACPI
static const struct acpi_device_id xgene_gpio_acpi_match[] = {
	{ "APMC0D14", 0 },
	{ },
};
#endif

static struct platform_driver xgene_gpio_driver = {
	.driver = {
		.name = "xgene-gpio",
		.of_match_table = xgene_gpio_of_match,
		.acpi_match_table = ACPI_PTR(xgene_gpio_acpi_match),
		.pm     = &xgene_gpio_pm,
	},
	.probe = xgene_gpio_probe,
};
builtin_platform_driver(xgene_gpio_driver);