1// SPDX-License-Identifier: GPL-2.0+
2/* Copyright (C) 2019 Stephan Gerhold */
3
4#include <common.h>
5#include <dm.h>
6#include <asm/gpio.h>
7#include <asm/io.h>
8
9struct nmk_gpio_regs {
10	u32 dat;	/* data */
11	u32 dats;	/* data set */
12	u32 datc;	/* data clear */
13	u32 pdis;	/* pull disable */
14	u32 dir;	/* direction */
15	u32 dirs;	/* direction set */
16	u32 dirc;	/* direction clear */
17	u32 slpm;	/* sleep mode */
18	u32 afsla;	/* alternate function select A */
19	u32 afslb;	/* alternate function select B */
20	u32 lowemi;	/* low EMI mode */
21};
22
23struct nmk_gpio {
24	struct nmk_gpio_regs *regs;
25};
26
27static int nmk_gpio_get_value(struct udevice *dev, unsigned offset)
28{
29	struct nmk_gpio *priv = dev_get_priv(dev);
30
31	return !!(readl(&priv->regs->dat) & BIT(offset));
32}
33
34static int nmk_gpio_set_value(struct udevice *dev, unsigned offset, int value)
35{
36	struct nmk_gpio *priv = dev_get_priv(dev);
37
38	if (value)
39		writel(BIT(offset), &priv->regs->dats);
40	else
41		writel(BIT(offset), &priv->regs->datc);
42
43	return 0;
44}
45
46static int nmk_gpio_get_function(struct udevice *dev, unsigned offset)
47{
48	struct nmk_gpio *priv = dev_get_priv(dev);
49
50	if (readl(&priv->regs->afsla) & BIT(offset) ||
51	    readl(&priv->regs->afslb) & BIT(offset))
52		return GPIOF_FUNC;
53
54	if (readl(&priv->regs->dir) & BIT(offset))
55		return GPIOF_OUTPUT;
56	else
57		return GPIOF_INPUT;
58}
59
60static int nmk_gpio_direction_input(struct udevice *dev, unsigned offset)
61{
62	struct nmk_gpio *priv = dev_get_priv(dev);
63
64	writel(BIT(offset), &priv->regs->dirc);
65	return 0;
66}
67
68static int nmk_gpio_direction_output(struct udevice *dev, unsigned offset,
69				     int value)
70{
71	struct nmk_gpio *priv = dev_get_priv(dev);
72
73	writel(BIT(offset), &priv->regs->dirs);
74	return nmk_gpio_set_value(dev, offset, value);
75}
76
77static const struct dm_gpio_ops nmk_gpio_ops = {
78	.get_value		= nmk_gpio_get_value,
79	.set_value		= nmk_gpio_set_value,
80	.get_function		= nmk_gpio_get_function,
81	.direction_input	= nmk_gpio_direction_input,
82	.direction_output	= nmk_gpio_direction_output,
83};
84
85static int nmk_gpio_probe(struct udevice *dev)
86{
87	struct nmk_gpio *priv = dev_get_priv(dev);
88	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
89	char buf[20];
90	u32 bank;
91	int ret;
92
93	priv->regs = dev_read_addr_ptr(dev);
94	if (!priv->regs)
95		return -EINVAL;
96
97	ret = dev_read_u32(dev, "gpio-bank", &bank);
98	if (ret < 0) {
99		printf("nmk_gpio(%s): Failed to read gpio-bank\n", dev->name);
100		return ret;
101	}
102
103	sprintf(buf, "nmk%u-gpio", bank);
104	uc_priv->bank_name = strdup(buf);
105	if (!uc_priv->bank_name)
106		return -ENOMEM;
107
108	uc_priv->gpio_count = sizeof(priv->regs->dat) * BITS_PER_BYTE;
109
110	return 0;
111}
112
113static const struct udevice_id nmk_gpio_ids[] = {
114	{ .compatible = "st,nomadik-gpio" },
115	{ }
116};
117
118U_BOOT_DRIVER(gpio_nmk) = {
119	.name		= "nmk_gpio",
120	.id		= UCLASS_GPIO,
121	.of_match	= nmk_gpio_ids,
122	.probe		= nmk_gpio_probe,
123	.ops		= &nmk_gpio_ops,
124	.priv_auto	= sizeof(struct nmk_gpio),
125};
126