projects / mirror_ubuntu-hirsute-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| 16d44b60 SE |
1 | // SPDX-License-Identifier: GPL-2.0-only |
| 2 | /* | |
| 3 | * Driver for PCA9570 I2C GPO expander | |
| 4 | * | |
| 5 | * Copyright (C) 2020 Sungbo Eo <mans0n@gorani.run> | |
| 6 | * | |
| 7 | * Based on gpio-tpic2810.c | |
| 8 | * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/ | |
| 9 | * Andrew F. Davis <afd@ti.com> | |
| 10 | */ | |
| 11 | ||
| 12 | #include <linux/gpio/driver.h> | |
| 13 | #include <linux/i2c.h> | |
| 14 | #include <linux/module.h> | |
| 15 | #include <linux/mutex.h> | |
| 16 | #include <linux/property.h> | |
| 17 | ||
| 18 | /** | |
| 19 | * struct pca9570 - GPIO driver data | |
| 20 | * @chip: GPIO controller chip | |
| 21 | * @lock: Protects write sequences | |
| 22 | * @out: Buffer for device register | |
| 23 | */ | |
| 24 | struct pca9570 { | |
| 25 | struct gpio_chip chip; | |
| 26 | struct mutex lock; | |
| 27 | u8 out; | |
| 28 | }; | |
| 29 | ||
| 30 | static int pca9570_read(struct pca9570 *gpio, u8 *value) | |
| 31 | { | |
| 32 | struct i2c_client *client = to_i2c_client(gpio->chip.parent); | |
| 33 | int ret; | |
| 34 | ||
| 35 | ret = i2c_smbus_read_byte(client); | |
| 36 | if (ret < 0) | |
| 37 | return ret; | |
| 38 | ||
| 39 | *value = ret; | |
| 40 | return 0; | |
| 41 | } | |
| 42 | ||
| 43 | static int pca9570_write(struct pca9570 *gpio, u8 value) | |
| 44 | { | |
| 45 | struct i2c_client *client = to_i2c_client(gpio->chip.parent); | |
| 46 | ||
| 47 | return i2c_smbus_write_byte(client, value); | |
| 48 | } | |
| 49 | ||
| 50 | static int pca9570_get_direction(struct gpio_chip *chip, | |
| 51 | unsigned offset) | |
| 52 | { | |
| 53 | /* This device always output */ | |
| 54 | return GPIO_LINE_DIRECTION_OUT; | |
| 55 | } | |
| 56 | ||
| 57 | static int pca9570_get(struct gpio_chip *chip, unsigned offset) | |
| 58 | { | |
| 59 | struct pca9570 *gpio = gpiochip_get_data(chip); | |
| 60 | u8 buffer; | |
| 61 | int ret; | |
| 62 | ||
| 63 | ret = pca9570_read(gpio, &buffer); | |
| 64 | if (ret) | |
| 65 | return ret; | |
| 66 | ||
| 67 | return !!(buffer & BIT(offset)); | |
| 68 | } | |
| 69 | ||
| 70 | static void pca9570_set(struct gpio_chip *chip, unsigned offset, int value) | |
| 71 | { | |
| 72 | struct pca9570 *gpio = gpiochip_get_data(chip); | |
| 73 | u8 buffer; | |
| 74 | int ret; | |
| 75 | ||
| 76 | mutex_lock(&gpio->lock); | |
| 77 | ||
| 78 | buffer = gpio->out; | |
| 79 | if (value) | |
| 80 | buffer |= BIT(offset); | |
| 81 | else | |
| 82 | buffer &= ~BIT(offset); | |
| 83 | ||
| 84 | ret = pca9570_write(gpio, buffer); | |
| 85 | if (ret) | |
| 86 | goto out; | |
| 87 | ||
| 88 | gpio->out = buffer; | |
| 89 | ||
| 90 | out: | |
| 91 | mutex_unlock(&gpio->lock); | |
| 92 | } | |
| 93 | ||
| 94 | static int pca9570_probe(struct i2c_client *client) | |
| 95 | { | |
| 96 | struct pca9570 *gpio; | |
| 97 | ||
| 98 | gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL); | |
| 99 | if (!gpio) | |
| 100 | return -ENOMEM; | |
| 101 | ||
| 102 | gpio->chip.label = client->name; | |
| 103 | gpio->chip.parent = &client->dev; | |
| 104 | gpio->chip.owner = THIS_MODULE; | |
| 105 | gpio->chip.get_direction = pca9570_get_direction; | |
| 106 | gpio->chip.get = pca9570_get; | |
| 107 | gpio->chip.set = pca9570_set; | |
| 108 | gpio->chip.base = -1; | |
| 109 | gpio->chip.ngpio = (uintptr_t)device_get_match_data(&client->dev); | |
| 110 | gpio->chip.can_sleep = true; | |
| 111 | ||
| 112 | mutex_init(&gpio->lock); | |
| 113 | ||
| 114 | /* Read the current output level */ | |
| 115 | pca9570_read(gpio, &gpio->out); | |
| 116 | ||
| 117 | i2c_set_clientdata(client, gpio); | |
| 118 | ||
| 119 | return devm_gpiochip_add_data(&client->dev, &gpio->chip, gpio); | |
| 120 | } | |
| 121 | ||
| 122 | static const struct i2c_device_id pca9570_id_table[] = { | |
| 123 | { "pca9570", 4 }, | |
| 124 | { /* sentinel */ } | |
| 125 | }; | |
| 126 | MODULE_DEVICE_TABLE(i2c, pca9570_id_table); | |
| 127 | ||
| 128 | static const struct of_device_id pca9570_of_match_table[] = { | |
| 129 | { .compatible = "nxp,pca9570", .data = (void *)4 }, | |
| 130 | { /* sentinel */ } | |
| 131 | }; | |
| 132 | MODULE_DEVICE_TABLE(of, pca9570_of_match_table); | |
| 133 | ||
| 134 | static struct i2c_driver pca9570_driver = { | |
| 135 | .driver = { | |
| 136 | .name = "pca9570", | |
| 137 | .of_match_table = pca9570_of_match_table, | |
| 138 | }, | |
| 139 | .probe_new = pca9570_probe, | |
| 140 | .id_table = pca9570_id_table, | |
| 141 | }; | |
| 142 | module_i2c_driver(pca9570_driver); | |
| 143 | ||
| 144 | MODULE_AUTHOR("Sungbo Eo <mans0n@gorani.run>"); | |
| 145 | MODULE_DESCRIPTION("GPIO expander driver for PCA9570"); | |
| 146 | MODULE_LICENSE("GPL v2"); |