summaryrefslogtreecommitdiff
path: root/drivers/gpio/bcm2835_gpio.c
blob: ccf84fdae11f292e494dc4562b74b51d5dcc1dbd (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
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2012 Vikram Narayananan
 * <vikram186@gmail.com>
 */

#include <dm.h>
#include <dm/pinctrl.h>
#include <errno.h>
#include <asm/gpio.h>
#include <asm/io.h>
#include <fdtdec.h>

struct bcm2835_gpios {
	struct bcm2835_gpio_regs *reg;
	struct udevice *pinctrl;
};

static int bcm2835_gpio_direction_input(struct udevice *dev, unsigned gpio)
{
	struct bcm2835_gpios *gpios = dev_get_priv(dev);
	unsigned val;

	val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
	val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
	val |= (BCM2835_GPIO_INPUT << BCM2835_GPIO_FSEL_SHIFT(gpio));
	writel(val, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);

	return 0;
}

static int bcm2835_gpio_direction_output(struct udevice *dev, unsigned int gpio,
					 int value)
{
	struct bcm2835_gpios *gpios = dev_get_priv(dev);
	unsigned val;

	gpio_set_value(gpio, value);

	val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
	val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
	val |= (BCM2835_GPIO_OUTPUT << BCM2835_GPIO_FSEL_SHIFT(gpio));
	writel(val, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);

	return 0;
}

static int bcm2835_get_value(const struct bcm2835_gpios *gpios, unsigned gpio)
{
	unsigned val;

	val = readl(&gpios->reg->gplev[BCM2835_GPIO_COMMON_BANK(gpio)]);

	return (val >> BCM2835_GPIO_COMMON_SHIFT(gpio)) & 0x1;
}

static int bcm2835_gpio_get_value(struct udevice *dev, unsigned gpio)
{
	const struct bcm2835_gpios *gpios = dev_get_priv(dev);

	return bcm2835_get_value(gpios, gpio);
}

static int bcm2835_gpio_set_value(struct udevice *dev, unsigned gpio,
				  int value)
{
	struct bcm2835_gpios *gpios = dev_get_priv(dev);
	u32 *output_reg = value ? gpios->reg->gpset : gpios->reg->gpclr;

	writel(1 << BCM2835_GPIO_COMMON_SHIFT(gpio),
				&output_reg[BCM2835_GPIO_COMMON_BANK(gpio)]);

	return 0;
}

static int bcm2835_gpio_get_function(struct udevice *dev, unsigned offset)
{
	struct bcm2835_gpios *priv = dev_get_priv(dev);
	int funcid;

	funcid = pinctrl_get_gpio_mux(priv->pinctrl, 0, offset);

	switch (funcid) {
	case BCM2835_GPIO_OUTPUT:
		return GPIOF_OUTPUT;
	case BCM2835_GPIO_INPUT:
		return GPIOF_INPUT;
	default:
		return GPIOF_FUNC;
	}
}

static const struct dm_gpio_ops gpio_bcm2835_ops = {
	.direction_input	= bcm2835_gpio_direction_input,
	.direction_output	= bcm2835_gpio_direction_output,
	.get_value		= bcm2835_gpio_get_value,
	.set_value		= bcm2835_gpio_set_value,
	.get_function		= bcm2835_gpio_get_function,
};

static int bcm2835_gpio_probe(struct udevice *dev)
{
	struct bcm2835_gpios *gpios = dev_get_priv(dev);
	struct bcm2835_gpio_plat *plat = dev_get_plat(dev);
	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);

	uc_priv->bank_name = "GPIO";
	uc_priv->gpio_count = BCM2835_GPIO_COUNT;
	gpios->reg = (struct bcm2835_gpio_regs *)plat->base;

	/* We know we're spawned by the pinctrl driver */
	gpios->pinctrl = dev->parent;

	return 0;
}

#if CONFIG_IS_ENABLED(OF_CONTROL)
static int bcm2835_gpio_of_to_plat(struct udevice *dev)
{
	struct bcm2835_gpio_plat *plat = dev_get_plat(dev);
	fdt_addr_t addr;

	addr = dev_read_addr(dev);
	if (addr == FDT_ADDR_T_NONE)
		return -EINVAL;

	plat->base = addr;
	return 0;
}
#endif

U_BOOT_DRIVER(gpio_bcm2835) = {
	.name	= "gpio_bcm2835",
	.id	= UCLASS_GPIO,
	.of_to_plat = of_match_ptr(bcm2835_gpio_of_to_plat),
	.plat_auto	= sizeof(struct bcm2835_gpio_plat),
	.ops	= &gpio_bcm2835_ops,
	.probe	= bcm2835_gpio_probe,
	.flags	= DM_FLAG_PRE_RELOC,
	.priv_auto	= sizeof(struct bcm2835_gpios),
};