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
16 struct max7320_chip {
17 u32 outreg;
18 };
19
max7320_direction_output(struct udevice * dev,unsigned int offset,int value)20 static 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
max7320_get_value(struct udevice * dev,unsigned int offset)45 static 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
max7320_set_value(struct udevice * dev,unsigned int offset,int value)52 static int max7320_set_value(struct udevice *dev, unsigned int offset,
53 int value)
54 {
55 return max7320_direction_output(dev, offset, value);
56 }
57
max7320_get_function(struct udevice * dev,unsigned int offset)58 static int max7320_get_function(struct udevice *dev, unsigned int offset)
59 {
60 return GPIOF_OUTPUT;
61 }
62
max7320_ofdata_plat(struct udevice * dev)63 static 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
max7320_gpio_probe(struct udevice * dev)83 static 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
93 static 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
100 static const struct udevice_id max7320_gpio_ids[] = {
101 { .compatible = "maxim,max7320" },
102 { }
103 };
104
105 U_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