aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/gpio/gpio-tz1090-pdc.c
blob: ede7e403ffdee8565530de696e77af69f083e7e7 (plain) (blame)
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
/*
 * Toumaz Xenif TZ1090 PDC GPIO handling.
 *
 * Copyright (C) 2012-2013 Imagination Technologies Ltd.
 *
 * 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/bitops.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/syscore_ops.h>
#include <asm/global_lock.h>

/* Register offsets from SOC_GPIO_CONTROL0 */
#define REG_SOC_GPIO_CONTROL0	0x00
#define REG_SOC_GPIO_CONTROL1	0x04
#define REG_SOC_GPIO_CONTROL2	0x08
#define REG_SOC_GPIO_CONTROL3	0x0c
#define REG_SOC_GPIO_STATUS	0x80

/* PDC GPIOs go after normal GPIOs */
#define GPIO_PDC_BASE		90
#define GPIO_PDC_NGPIO		7

/* Out of PDC gpios, only syswakes have irqs */
#define GPIO_PDC_IRQ_FIRST	2
#define GPIO_PDC_NIRQ		3

/**
 * struct tz1090_pdc_gpio - GPIO bank private data
 * @chip:	Generic GPIO chip for GPIO bank
 * @reg:	Base of registers, offset for this GPIO bank
 * @irq:	IRQ numbers for Syswake GPIOs
 *
 * This is the main private data for the PDC GPIO driver. It encapsulates a
 * gpio_chip, and the callbacks for the gpio_chip can access the private data
 * with the to_pdc() macro below.
 */
struct tz1090_pdc_gpio {
	struct gpio_chip chip;
	void __iomem *reg;
	int irq[GPIO_PDC_NIRQ];
};
#define to_pdc(c)	container_of(c, struct tz1090_pdc_gpio, chip)

/* Register accesses into the PDC MMIO area */

static inline void pdc_write(struct tz1090_pdc_gpio *priv, unsigned int reg_offs,
		      unsigned int data)
{
	writel(data, priv->reg + reg_offs);
}

static inline unsigned int pdc_read(struct tz1090_pdc_gpio *priv,
			     unsigned int reg_offs)
{
	return readl(priv->reg + reg_offs);
}

/* Generic GPIO interface */

static int tz1090_pdc_gpio_direction_input(struct gpio_chip *chip,
					   unsigned int offset)
{
	struct tz1090_pdc_gpio *priv = to_pdc(chip);
	u32 value;
	int lstat;

	__global_lock2(lstat);
	value = pdc_read(priv, REG_SOC_GPIO_CONTROL1);
	value |= BIT(offset);
	pdc_write(priv, REG_SOC_GPIO_CONTROL1, value);
	__global_unlock2(lstat);

	return 0;
}

static int tz1090_pdc_gpio_direction_output(struct gpio_chip *chip,
					    unsigned int offset,
					    int output_value)
{
	struct tz1090_pdc_gpio *priv = to_pdc(chip);
	u32 value;
	int lstat;

	__global_lock2(lstat);
	/* EXT_POWER doesn't seem to have an output value bit */
	if (offset < 6) {
		value = pdc_read(priv, REG_SOC_GPIO_CONTROL0);
		if (output_value)
			value |= BIT(offset);
		else
			value &= ~BIT(offset);
		pdc_write(priv, REG_SOC_GPIO_CONTROL0, value);
	}

	value = pdc_read(priv, REG_SOC_GPIO_CONTROL1);
	value &= ~BIT(offset);
	pdc_write(priv, REG_SOC_GPIO_CONTROL1, value);
	__global_unlock2(lstat);

	return 0;
}

static int tz1090_pdc_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
	struct tz1090_pdc_gpio *priv = to_pdc(chip);
	return pdc_read(priv, REG_SOC_GPIO_STATUS) & BIT(offset);
}

static void tz1090_pdc_gpio_set(struct gpio_chip *chip, unsigned int offset,
				int output_value)
{
	struct tz1090_pdc_gpio *priv = to_pdc(chip);
	u32 value;
	int lstat;

	/* EXT_POWER doesn't seem to have an output value bit */
	if (offset >= 6)
		return;

	__global_lock2(lstat);
	value = pdc_read(priv, REG_SOC_GPIO_CONTROL0);
	if (output_value)
		value |= BIT(offset);
	else
		value &= ~BIT(offset);
	pdc_write(priv, REG_SOC_GPIO_CONTROL0, value);
	__global_unlock2(lstat);
}

static int tz1090_pdc_gpio_request(struct gpio_chip *chip, unsigned int offset)
{
	return pinctrl_request_gpio(chip->base + offset);
}

static void tz1090_pdc_gpio_free(struct gpio_chip *chip, unsigned int offset)
{
	pinctrl_free_gpio(chip->base + offset);
}

static int tz1090_pdc_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
{
	struct tz1090_pdc_gpio *priv = to_pdc(chip);
	unsigned int syswake = offset - GPIO_PDC_IRQ_FIRST;
	int irq;

	/* only syswakes have irqs */
	if (syswake >= GPIO_PDC_NIRQ)
		return -EINVAL;

	irq = priv->irq[syswake];
	if (!irq)
		return -EINVAL;

	return irq;
}

static int tz1090_pdc_gpio_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct resource *res_regs;
	struct tz1090_pdc_gpio *priv;
	unsigned int i;

	if (!np) {
		dev_err(&pdev->dev, "must be instantiated via devicetree\n");
		return -ENOENT;
	}

	res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res_regs) {
		dev_err(&pdev->dev, "cannot find registers resource\n");
		return -ENOENT;
	}

	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv) {
		dev_err(&pdev->dev, "unable to allocate driver data\n");
		return -ENOMEM;
	}

	/* Ioremap the registers */
	priv->reg = devm_ioremap(&pdev->dev, res_regs->start,
				 resource_size(res_regs));
	if (!priv->reg) {
		dev_err(&pdev->dev, "unable to ioremap registers\n");
		return -ENOMEM;
	}

	/* Set up GPIO chip */
	priv->chip.label		= "tz1090-pdc-gpio";
	priv->chip.dev			= &pdev->dev;
	priv->chip.direction_input	= tz1090_pdc_gpio_direction_input;
	priv->chip.direction_output	= tz1090_pdc_gpio_direction_output;
	priv->chip.get			= tz1090_pdc_gpio_get;
	priv->chip.set			= tz1090_pdc_gpio_set;
	priv->chip.free			= tz1090_pdc_gpio_free;
	priv->chip.request		= tz1090_pdc_gpio_request;
	priv->chip.to_irq		= tz1090_pdc_gpio_to_irq;
	priv->chip.of_node		= np;

	/* GPIO numbering */
	priv->chip.base			= GPIO_PDC_BASE;
	priv->chip.ngpio		= GPIO_PDC_NGPIO;

	/* Map the syswake irqs */
	for (i = 0; i < GPIO_PDC_NIRQ; ++i)
		priv->irq[i] = irq_of_parse_and_map(np, i);

	/* Add the GPIO bank */
	gpiochip_add(&priv->chip);

	return 0;
}

static struct of_device_id tz1090_pdc_gpio_of_match[] = {
	{ .compatible = "img,tz1090-pdc-gpio" },
	{ },
};

static struct platform_driver tz1090_pdc_gpio_driver = {
	.driver = {
		.name		= "tz1090-pdc-gpio",
		.of_match_table	= tz1090_pdc_gpio_of_match,
	},
	.probe		= tz1090_pdc_gpio_probe,
};

static int __init tz1090_pdc_gpio_init(void)
{
	return platform_driver_register(&tz1090_pdc_gpio_driver);
}
subsys_initcall(tz1090_pdc_gpio_init);