summaryrefslogtreecommitdiffstats
path: root/drivers/gpio/stm32_gpio.c
blob: 451724e83898f4916247bd4c9ab80d5ecccdae78 (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
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
 * Author(s): Vikas Manocha, <vikas.manocha@st.com> for STMicroelectronics.
 */

#include <common.h>
#include <clk.h>
#include <dm.h>
#include <fdtdec.h>
#include <log.h>
#include <asm/arch/gpio.h>
#include <asm/arch/stm32.h>
#include <asm/gpio.h>
#include <asm/io.h>
#include <dm/device_compat.h>
#include <linux/errno.h>
#include <linux/io.h>

#define MODE_BITS(gpio_pin)		(gpio_pin * 2)
#define MODE_BITS_MASK			3
#define BSRR_BIT(gpio_pin, value)	BIT(gpio_pin + (value ? 0 : 16))

/*
 * convert gpio offset to gpio index taking into account gpio holes
 * into gpio bank
 */
int stm32_offset_to_index(struct udevice *dev, unsigned int offset)
{
	struct stm32_gpio_priv *priv = dev_get_priv(dev);
	unsigned int idx = 0;
	int i;

	for (i = 0; i < STM32_GPIOS_PER_BANK; i++) {
		if (priv->gpio_range & BIT(i)) {
			if (idx == offset)
				return idx;
			idx++;
		}
	}
	/* shouldn't happen */
	return -EINVAL;
}

static int stm32_gpio_direction_input(struct udevice *dev, unsigned offset)
{
	struct stm32_gpio_priv *priv = dev_get_priv(dev);
	struct stm32_gpio_regs *regs = priv->regs;
	int bits_index;
	int mask;
	int idx;

	idx = stm32_offset_to_index(dev, offset);
	if (idx < 0)
		return idx;

	bits_index = MODE_BITS(idx);
	mask = MODE_BITS_MASK << bits_index;

	clrsetbits_le32(&regs->moder, mask, STM32_GPIO_MODE_IN << bits_index);

	return 0;
}

static int stm32_gpio_direction_output(struct udevice *dev, unsigned offset,
				       int value)
{
	struct stm32_gpio_priv *priv = dev_get_priv(dev);
	struct stm32_gpio_regs *regs = priv->regs;
	int bits_index;
	int mask;
	int idx;

	idx = stm32_offset_to_index(dev, offset);
	if (idx < 0)
		return idx;

	bits_index = MODE_BITS(idx);
	mask = MODE_BITS_MASK << bits_index;

	clrsetbits_le32(&regs->moder, mask, STM32_GPIO_MODE_OUT << bits_index);

	writel(BSRR_BIT(idx, value), &regs->bsrr);

	return 0;
}

static int stm32_gpio_get_value(struct udevice *dev, unsigned offset)
{
	struct stm32_gpio_priv *priv = dev_get_priv(dev);
	struct stm32_gpio_regs *regs = priv->regs;
	int idx;

	idx = stm32_offset_to_index(dev, offset);
	if (idx < 0)
		return idx;

	return readl(&regs->idr) & BIT(idx) ? 1 : 0;
}

static int stm32_gpio_set_value(struct udevice *dev, unsigned offset, int value)
{
	struct stm32_gpio_priv *priv = dev_get_priv(dev);
	struct stm32_gpio_regs *regs = priv->regs;
	int idx;

	idx = stm32_offset_to_index(dev, offset);
	if (idx < 0)
		return idx;

	writel(BSRR_BIT(idx, value), &regs->bsrr);

	return 0;
}

static int stm32_gpio_get_function(struct udevice *dev, unsigned int offset)
{
	struct stm32_gpio_priv *priv = dev_get_priv(dev);
	struct stm32_gpio_regs *regs = priv->regs;
	int bits_index;
	int mask;
	int idx;
	u32 mode;

	idx = stm32_offset_to_index(dev, offset);
	if (idx < 0)
		return idx;

	bits_index = MODE_BITS(idx);
	mask = MODE_BITS_MASK << bits_index;

	mode = (readl(&regs->moder) & mask) >> bits_index;
	if (mode == STM32_GPIO_MODE_OUT)
		return GPIOF_OUTPUT;
	if (mode == STM32_GPIO_MODE_IN)
		return GPIOF_INPUT;
	if (mode == STM32_GPIO_MODE_AN)
		return GPIOF_UNUSED;

	return GPIOF_FUNC;
}

static const struct dm_gpio_ops gpio_stm32_ops = {
	.direction_input	= stm32_gpio_direction_input,
	.direction_output	= stm32_gpio_direction_output,
	.get_value		= stm32_gpio_get_value,
	.set_value		= stm32_gpio_set_value,
	.get_function		= stm32_gpio_get_function,
};

static int gpio_stm32_probe(struct udevice *dev)
{
	struct stm32_gpio_priv *priv = dev_get_priv(dev);
	struct clk clk;
	fdt_addr_t addr;
	int ret;

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

	priv->regs = (struct stm32_gpio_regs *)addr;

	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
	struct ofnode_phandle_args args;
	const char *name;
	int i;

	name = dev_read_string(dev, "st,bank-name");
	if (!name)
		return -EINVAL;
	uc_priv->bank_name = name;

	i = 0;
	ret = dev_read_phandle_with_args(dev, "gpio-ranges",
					 NULL, 3, i, &args);

	if (ret == -ENOENT) {
		uc_priv->gpio_count = STM32_GPIOS_PER_BANK;
		priv->gpio_range = GENMASK(STM32_GPIOS_PER_BANK - 1, 0);
	}

	while (ret != -ENOENT) {
		priv->gpio_range |= GENMASK(args.args[2] + args.args[0] - 1,
				    args.args[0]);

		uc_priv->gpio_count += args.args[2];

		ret = dev_read_phandle_with_args(dev, "gpio-ranges", NULL, 3,
						 ++i, &args);
	}

	dev_dbg(dev, "addr = 0x%p bank_name = %s gpio_count = %d gpio_range = 0x%x\n",
		(u32 *)priv->regs, uc_priv->bank_name, uc_priv->gpio_count,
		priv->gpio_range);

	ret = clk_get_by_index(dev, 0, &clk);
	if (ret < 0)
		return ret;

	ret = clk_enable(&clk);

	if (ret) {
		dev_err(dev, "failed to enable clock\n");
		return ret;
	}
	debug("clock enabled for device %s\n", dev->name);

	return 0;
}

U_BOOT_DRIVER(gpio_stm32) = {
	.name	= "gpio_stm32",
	.id	= UCLASS_GPIO,
	.probe	= gpio_stm32_probe,
	.ops	= &gpio_stm32_ops,
	.flags	= DM_UC_FLAG_SEQ_ALIAS,
	.priv_auto_alloc_size	= sizeof(struct stm32_gpio_priv),
};