summaryrefslogtreecommitdiffstats
path: root/drivers/gpio/gpio-ath79.c
blob: 5eaea8b812cf39515c3e7132d90d4f3d7e0fba17 (plain)
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
/*
 *  Atheros AR71XX/AR724X/AR913X GPIO API support
 *
 *  Copyright (C) 2010-2011 Jaiganesh Narayanan <jnarayanan@atheros.com>
 *  Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
 *  Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
 *
 *  Parts of this file are based on Atheros' 2.6.15/2.6.31 BSP
 *
 *  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.
 */

#include <linux/gpio/driver.h>
#include <linux/platform_data/gpio-ath79.h>
#include <linux/of_device.h>

#include <asm/mach-ath79/ar71xx_regs.h>

struct ath79_gpio_ctrl {
	struct gpio_chip chip;
	void __iomem *base;
	spinlock_t lock;
};

#define to_ath79_gpio_ctrl(c) container_of(c, struct ath79_gpio_ctrl, chip)

static void ath79_gpio_set_value(struct gpio_chip *chip,
				unsigned gpio, int value)
{
	struct ath79_gpio_ctrl *ctrl = to_ath79_gpio_ctrl(chip);

	if (value)
		__raw_writel(BIT(gpio), ctrl->base + AR71XX_GPIO_REG_SET);
	else
		__raw_writel(BIT(gpio), ctrl->base + AR71XX_GPIO_REG_CLEAR);
}

static int ath79_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
{
	struct ath79_gpio_ctrl *ctrl = to_ath79_gpio_ctrl(chip);

	return (__raw_readl(ctrl->base + AR71XX_GPIO_REG_IN) >> gpio) & 1;
}

static int ath79_gpio_direction_input(struct gpio_chip *chip,
				       unsigned offset)
{
	struct ath79_gpio_ctrl *ctrl = to_ath79_gpio_ctrl(chip);
	unsigned long flags;

	spin_lock_irqsave(&ctrl->lock, flags);

	__raw_writel(
		__raw_readl(ctrl->base + AR71XX_GPIO_REG_OE) & ~BIT(offset),
		ctrl->base + AR71XX_GPIO_REG_OE);

	spin_unlock_irqrestore(&ctrl->lock, flags);

	return 0;
}

static int ath79_gpio_direction_output(struct gpio_chip *chip,
					unsigned offset, int value)
{
	struct ath79_gpio_ctrl *ctrl = to_ath79_gpio_ctrl(chip);
	unsigned long flags;

	spin_lock_irqsave(&ctrl->lock, flags);

	if (value)
		__raw_writel(BIT(offset), ctrl->base + AR71XX_GPIO_REG_SET);
	else
		__raw_writel(BIT(offset), ctrl->base + AR71XX_GPIO_REG_CLEAR);

	__raw_writel(
		__raw_readl(ctrl->base + AR71XX_GPIO_REG_OE) | BIT(offset),
		ctrl->base + AR71XX_GPIO_REG_OE);

	spin_unlock_irqrestore(&ctrl->lock, flags);

	return 0;
}

static int ar934x_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
	struct ath79_gpio_ctrl *ctrl = to_ath79_gpio_ctrl(chip);
	unsigned long flags;

	spin_lock_irqsave(&ctrl->lock, flags);

	__raw_writel(
		__raw_readl(ctrl->base + AR71XX_GPIO_REG_OE) | BIT(offset),
		ctrl->base + AR71XX_GPIO_REG_OE);

	spin_unlock_irqrestore(&ctrl->lock, flags);

	return 0;
}

static int ar934x_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
					int value)
{
	struct ath79_gpio_ctrl *ctrl = to_ath79_gpio_ctrl(chip);
	unsigned long flags;

	spin_lock_irqsave(&ctrl->lock, flags);

	if (value)
		__raw_writel(BIT(offset), ctrl->base + AR71XX_GPIO_REG_SET);
	else
		__raw_writel(BIT(offset), ctrl->base + AR71XX_GPIO_REG_CLEAR);

	__raw_writel(
		__raw_readl(ctrl->base + AR71XX_GPIO_REG_OE) & ~BIT(offset),
		ctrl->base + AR71XX_GPIO_REG_OE);

	spin_unlock_irqrestore(&ctrl->lock, flags);

	return 0;
}

static const struct gpio_chip ath79_gpio_chip = {
	.label			= "ath79",
	.get			= ath79_gpio_get_value,
	.set			= ath79_gpio_set_value,
	.direction_input	= ath79_gpio_direction_input,
	.direction_output	= ath79_gpio_direction_output,
	.base			= 0,
};

static const struct of_device_id ath79_gpio_of_match[] = {
	{ .compatible = "qca,ar7100-gpio" },
	{ .compatible = "qca,ar9340-gpio" },
	{},
};

static int ath79_gpio_probe(struct platform_device *pdev)
{
	struct ath79_gpio_platform_data *pdata = pdev->dev.platform_data;
	struct device_node *np = pdev->dev.of_node;
	struct ath79_gpio_ctrl *ctrl;
	struct resource *res;
	u32 ath79_gpio_count;
	bool oe_inverted;
	int err;

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

	if (np) {
		err = of_property_read_u32(np, "ngpios", &ath79_gpio_count);
		if (err) {
			dev_err(&pdev->dev, "ngpios property is not valid\n");
			return err;
		}
		if (ath79_gpio_count >= 32) {
			dev_err(&pdev->dev, "ngpios must be less than 32\n");
			return -EINVAL;
		}
		oe_inverted = of_device_is_compatible(np, "qca,ar9340-gpio");
	} else if (pdata) {
		ath79_gpio_count = pdata->ngpios;
		oe_inverted = pdata->oe_inverted;
	} else {
		dev_err(&pdev->dev, "No DT node or platform data found\n");
		return -EINVAL;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	ctrl->base = devm_ioremap_nocache(
		&pdev->dev, res->start, resource_size(res));
	if (!ctrl->base)
		return -ENOMEM;

	spin_lock_init(&ctrl->lock);
	memcpy(&ctrl->chip, &ath79_gpio_chip, sizeof(ctrl->chip));
	ctrl->chip.dev = &pdev->dev;
	ctrl->chip.ngpio = ath79_gpio_count;
	if (oe_inverted) {
		ctrl->chip.direction_input = ar934x_gpio_direction_input;
		ctrl->chip.direction_output = ar934x_gpio_direction_output;
	}

	err = gpiochip_add(&ctrl->chip);
	if (err) {
		dev_err(&pdev->dev,
			"cannot add AR71xx GPIO chip, error=%d", err);
		return err;
	}

	return 0;
}

static struct platform_driver ath79_gpio_driver = {
	.driver = {
		.name = "ath79-gpio",
		.of_match_table	= ath79_gpio_of_match,
	},
	.probe = ath79_gpio_probe,
};

module_platform_driver(ath79_gpio_driver);
OpenPOWER on IntegriCloud