1// SPDX-License-Identifier: GPL-2.0
2/*
3 * max7320 I2C GPIO EXPANDER DRIVER
4 *
5 * Copyright (C) 2021 Hannes Schmelzer <oe5hpm@oevsv.at>
6 * B&R Industrial Automation GmbH - http://www.br-automation.com
7 *
8 */
9
10#include <common.h>
11#include <dm.h>
12#include <i2c.h>
13#include <asm-generic/gpio.h>
14#include <linux/bitops.h>
15
16struct max7320_chip {
17	u32 outreg;
18};
19
20static int max7320_direction_output(struct udevice *dev,
21				    unsigned int offset, int value)
22{
23	struct max7320_chip *plat = dev_get_plat(dev);
24	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
25	struct dm_i2c_chip *chip = dev_get_parent_plat(dev);
26
27	int ret;
28
29	if (value)
30		plat->outreg |= BIT(offset);
31	else
32		plat->outreg &= ~BIT(offset);
33
34	ret = dm_i2c_write(dev,
35			   plat->outreg & 0xff,
36			   (uint8_t *)&plat->outreg + 1,
37			   uc_priv->gpio_count > 8 ? 1 : 0);
38	if (ret)
39		printf("%s i2c write failed to addr %x\n", __func__,
40		       chip->chip_addr);
41
42	return ret;
43}
44
45static int max7320_get_value(struct udevice *dev, unsigned int offset)
46{
47	struct max7320_chip *plat = dev_get_plat(dev);
48
49	return (plat->outreg >> offset) & 0x1;
50}
51
52static int max7320_set_value(struct udevice *dev, unsigned int offset,
53			     int value)
54{
55	return max7320_direction_output(dev, offset, value);
56}
57
58static int max7320_get_function(struct udevice *dev, unsigned int offset)
59{
60	return GPIOF_OUTPUT;
61}
62
63static int max7320_ofdata_plat(struct udevice *dev)
64{
65	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
66
67	uc_priv->gpio_count = dev_read_u32_default(dev, "ngpios", 8);
68	if (uc_priv->gpio_count > 16) {
69		printf("%s: max7320 doesn't support more than 16 gpios!",
70		       __func__);
71		return -EINVAL;
72	}
73
74	uc_priv->bank_name = fdt_getprop(gd->fdt_blob, dev_of_offset(dev),
75					 "gpio-bank-name", NULL);
76	if (!uc_priv->bank_name)
77		uc_priv->bank_name = fdt_get_name(gd->fdt_blob,
78						  dev_of_offset(dev), NULL);
79
80	return 0;
81}
82
83static int max7320_gpio_probe(struct udevice  *dev)
84{
85	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
86
87	debug("%s GPIO controller with %d gpios probed\n",
88	      uc_priv->bank_name, uc_priv->gpio_count);
89
90	return 0;
91}
92
93static const struct dm_gpio_ops max7320_gpio_ops = {
94	.direction_output	= max7320_direction_output,
95	.set_value		= max7320_set_value,
96	.get_value		= max7320_get_value,
97	.get_function		= max7320_get_function,
98};
99
100static const struct udevice_id max7320_gpio_ids[] = {
101	{ .compatible = "maxim,max7320" },
102	{ }
103};
104
105U_BOOT_DRIVER(gpio_max7320) = {
106	.name		= "gpio_max7320",
107	.id		= UCLASS_GPIO,
108	.ops		= &max7320_gpio_ops,
109	.of_match	= max7320_gpio_ids,
110	.of_to_plat	= max7320_ofdata_plat,
111	.probe		= max7320_gpio_probe,
112	.plat_auto	= sizeof(struct max7320_chip),
113};
114