| Hannes Schmelzer | d3254ce | 2021-10-01 13:37:57 +0200 | [diff] [blame] | 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 | |
| 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 | |
| 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 | |
| 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 | |
| 58 | static int max7320_get_function(struct udevice *dev, unsigned int offset) |
| 59 | { |
| 60 | return GPIOF_OUTPUT; |
| 61 | } |
| 62 | |
| 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 | |
| 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 | }; |