summaryrefslogtreecommitdiff
path: root/drivers/gpio/gpio-ath79.c
blob: 018ea9d33b54142b836c49148c017504828ccd2d (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
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
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
/*
 *  Atheros AR71XX/AR724X/AR913X GPIO API support
 *
 *  Copyright (C) 2015 Alban Bedel <albeu@free.fr>
 *  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>
 *
 *  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 <linux/interrupt.h>
#include <linux/irq.h>

#define AR71XX_GPIO_REG_OE		0x00
#define AR71XX_GPIO_REG_IN		0x04
#define AR71XX_GPIO_REG_SET		0x0c
#define AR71XX_GPIO_REG_CLEAR		0x10

#define AR71XX_GPIO_REG_INT_ENABLE	0x14
#define AR71XX_GPIO_REG_INT_TYPE	0x18
#define AR71XX_GPIO_REG_INT_POLARITY	0x1c
#define AR71XX_GPIO_REG_INT_PENDING	0x20
#define AR71XX_GPIO_REG_INT_MASK	0x24

struct ath79_gpio_ctrl {
	struct gpio_chip gc;
	void __iomem *base;
	spinlock_t lock;
	unsigned long both_edges;
};

static struct ath79_gpio_ctrl *irq_data_to_ath79_gpio(struct irq_data *data)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);

	return container_of(gc, struct ath79_gpio_ctrl, gc);
}

static u32 ath79_gpio_read(struct ath79_gpio_ctrl *ctrl, unsigned reg)
{
	return readl(ctrl->base + reg);
}

static void ath79_gpio_write(struct ath79_gpio_ctrl *ctrl,
			unsigned reg, u32 val)
{
	return writel(val, ctrl->base + reg);
}

static bool ath79_gpio_update_bits(
	struct ath79_gpio_ctrl *ctrl, unsigned reg, u32 mask, u32 bits)
{
	u32 old_val, new_val;

	old_val = ath79_gpio_read(ctrl, reg);
	new_val = (old_val & ~mask) | (bits & mask);

	if (new_val != old_val)
		ath79_gpio_write(ctrl, reg, new_val);

	return new_val != old_val;
}

static void ath79_gpio_irq_unmask(struct irq_data *data)
{
	struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
	u32 mask = BIT(irqd_to_hwirq(data));
	unsigned long flags;

	spin_lock_irqsave(&ctrl->lock, flags);
	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask);
	spin_unlock_irqrestore(&ctrl->lock, flags);
}

static void ath79_gpio_irq_mask(struct irq_data *data)
{
	struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
	u32 mask = BIT(irqd_to_hwirq(data));
	unsigned long flags;

	spin_lock_irqsave(&ctrl->lock, flags);
	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0);
	spin_unlock_irqrestore(&ctrl->lock, flags);
}

static void ath79_gpio_irq_enable(struct irq_data *data)
{
	struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
	u32 mask = BIT(irqd_to_hwirq(data));
	unsigned long flags;

	spin_lock_irqsave(&ctrl->lock, flags);
	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask);
	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask);
	spin_unlock_irqrestore(&ctrl->lock, flags);
}

static void ath79_gpio_irq_disable(struct irq_data *data)
{
	struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
	u32 mask = BIT(irqd_to_hwirq(data));
	unsigned long flags;

	spin_lock_irqsave(&ctrl->lock, flags);
	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0);
	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0);
	spin_unlock_irqrestore(&ctrl->lock, flags);
}

static int ath79_gpio_irq_set_type(struct irq_data *data,
				unsigned int flow_type)
{
	struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
	u32 mask = BIT(irqd_to_hwirq(data));
	u32 type = 0, polarity = 0;
	unsigned long flags;
	bool disabled;

	switch (flow_type) {
	case IRQ_TYPE_EDGE_RISING:
		polarity |= mask;
	case IRQ_TYPE_EDGE_FALLING:
	case IRQ_TYPE_EDGE_BOTH:
		break;

	case IRQ_TYPE_LEVEL_HIGH:
		polarity |= mask;
	case IRQ_TYPE_LEVEL_LOW:
		type |= mask;
		break;

	default:
		return -EINVAL;
	}

	spin_lock_irqsave(&ctrl->lock, flags);

	if (flow_type == IRQ_TYPE_EDGE_BOTH) {
		ctrl->both_edges |= mask;
		polarity = ~ath79_gpio_read(ctrl, AR71XX_GPIO_REG_IN);
	} else {
		ctrl->both_edges &= ~mask;
	}

	/* As the IRQ configuration can't be loaded atomically we
	 * have to disable the interrupt while the configuration state
	 * is invalid.
	 */
	disabled = ath79_gpio_update_bits(
		ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0);

	ath79_gpio_update_bits(
		ctrl, AR71XX_GPIO_REG_INT_TYPE, mask, type);
	ath79_gpio_update_bits(
		ctrl, AR71XX_GPIO_REG_INT_POLARITY, mask, polarity);

	if (disabled)
		ath79_gpio_update_bits(
			ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask);

	spin_unlock_irqrestore(&ctrl->lock, flags);

	return 0;
}

static struct irq_chip ath79_gpio_irqchip = {
	.name = "gpio-ath79",
	.irq_enable = ath79_gpio_irq_enable,
	.irq_disable = ath79_gpio_irq_disable,
	.irq_mask = ath79_gpio_irq_mask,
	.irq_unmask = ath79_gpio_irq_unmask,
	.irq_set_type = ath79_gpio_irq_set_type,
};

static void ath79_gpio_irq_handler(struct irq_desc *desc)
{
	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
	struct irq_chip *irqchip = irq_desc_get_chip(desc);
	struct ath79_gpio_ctrl *ctrl =
		container_of(gc, struct ath79_gpio_ctrl, gc);
	unsigned long flags, pending;
	u32 both_edges, state;
	int irq;

	chained_irq_enter(irqchip, desc);

	spin_lock_irqsave(&ctrl->lock, flags);

	pending = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_INT_PENDING);

	/* Update the polarity of the both edges irqs */
	both_edges = ctrl->both_edges & pending;
	if (both_edges) {
		state = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_IN);
		ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_POLARITY,
				both_edges, ~state);
	}

	spin_unlock_irqrestore(&ctrl->lock, flags);

	if (pending) {
		for_each_set_bit(irq, &pending, gc->ngpio)
			generic_handle_irq(
				irq_linear_revmap(gc->irqdomain, irq));
	}

	chained_irq_exit(irqchip, desc);
}

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 = dev_get_platdata(&pdev->dev);
	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;
	platform_set_drvdata(pdev, ctrl);

	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);
	err = bgpio_init(&ctrl->gc, &pdev->dev, 4,
			ctrl->base + AR71XX_GPIO_REG_IN,
			ctrl->base + AR71XX_GPIO_REG_SET,
			ctrl->base + AR71XX_GPIO_REG_CLEAR,
			oe_inverted ? NULL : ctrl->base + AR71XX_GPIO_REG_OE,
			oe_inverted ? ctrl->base + AR71XX_GPIO_REG_OE : NULL,
			0);
	if (err) {
		dev_err(&pdev->dev, "bgpio_init failed\n");
		return err;
	}
	/* Use base 0 to stay compatible with legacy platforms */
	ctrl->gc.base = 0;

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

	if (np && !of_property_read_bool(np, "interrupt-controller"))
		return 0;

	err = gpiochip_irqchip_add(&ctrl->gc, &ath79_gpio_irqchip, 0,
				handle_simple_irq, IRQ_TYPE_NONE);
	if (err) {
		dev_err(&pdev->dev, "failed to add gpiochip_irqchip\n");
		goto gpiochip_remove;
	}

	gpiochip_set_chained_irqchip(&ctrl->gc, &ath79_gpio_irqchip,
				platform_get_irq(pdev, 0),
				ath79_gpio_irq_handler);

	return 0;

gpiochip_remove:
	gpiochip_remove(&ctrl->gc);
	return err;
}

static int ath79_gpio_remove(struct platform_device *pdev)
{
	struct ath79_gpio_ctrl *ctrl = platform_get_drvdata(pdev);

	gpiochip_remove(&ctrl->gc);
	return 0;
}

static struct platform_driver ath79_gpio_driver = {
	.driver = {
		.name = "ath79-gpio",
		.of_match_table	= ath79_gpio_of_match,
	},
	.probe = ath79_gpio_probe,
	.remove = ath79_gpio_remove,
};

module_platform_driver(ath79_gpio_driver);