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146 lines
3.1 KiB
146 lines
3.1 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Driver for PCA9570 I2C GPO expander |
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* |
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* Copyright (C) 2020 Sungbo Eo <[email protected]> |
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* |
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* Based on gpio-tpic2810.c |
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* Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/ |
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* Andrew F. Davis <[email protected]> |
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*/ |
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#include <linux/gpio/driver.h> |
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#include <linux/i2c.h> |
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#include <linux/module.h> |
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#include <linux/mutex.h> |
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#include <linux/property.h> |
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/** |
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* struct pca9570 - GPIO driver data |
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* @chip: GPIO controller chip |
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* @lock: Protects write sequences |
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* @out: Buffer for device register |
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*/ |
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struct pca9570 { |
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struct gpio_chip chip; |
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struct mutex lock; |
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u8 out; |
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}; |
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static int pca9570_read(struct pca9570 *gpio, u8 *value) |
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{ |
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struct i2c_client *client = to_i2c_client(gpio->chip.parent); |
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int ret; |
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ret = i2c_smbus_read_byte(client); |
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if (ret < 0) |
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return ret; |
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*value = ret; |
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return 0; |
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} |
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static int pca9570_write(struct pca9570 *gpio, u8 value) |
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{ |
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struct i2c_client *client = to_i2c_client(gpio->chip.parent); |
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return i2c_smbus_write_byte(client, value); |
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} |
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static int pca9570_get_direction(struct gpio_chip *chip, |
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unsigned offset) |
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{ |
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/* This device always output */ |
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return GPIO_LINE_DIRECTION_OUT; |
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} |
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static int pca9570_get(struct gpio_chip *chip, unsigned offset) |
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{ |
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struct pca9570 *gpio = gpiochip_get_data(chip); |
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u8 buffer; |
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int ret; |
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ret = pca9570_read(gpio, &buffer); |
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if (ret) |
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return ret; |
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return !!(buffer & BIT(offset)); |
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} |
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static void pca9570_set(struct gpio_chip *chip, unsigned offset, int value) |
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{ |
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struct pca9570 *gpio = gpiochip_get_data(chip); |
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u8 buffer; |
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int ret; |
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mutex_lock(&gpio->lock); |
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buffer = gpio->out; |
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if (value) |
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buffer |= BIT(offset); |
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else |
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buffer &= ~BIT(offset); |
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ret = pca9570_write(gpio, buffer); |
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if (ret) |
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goto out; |
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gpio->out = buffer; |
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out: |
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mutex_unlock(&gpio->lock); |
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} |
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static int pca9570_probe(struct i2c_client *client) |
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{ |
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struct pca9570 *gpio; |
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gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL); |
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if (!gpio) |
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return -ENOMEM; |
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gpio->chip.label = client->name; |
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gpio->chip.parent = &client->dev; |
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gpio->chip.owner = THIS_MODULE; |
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gpio->chip.get_direction = pca9570_get_direction; |
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gpio->chip.get = pca9570_get; |
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gpio->chip.set = pca9570_set; |
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gpio->chip.base = -1; |
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gpio->chip.ngpio = (uintptr_t)device_get_match_data(&client->dev); |
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gpio->chip.can_sleep = true; |
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mutex_init(&gpio->lock); |
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/* Read the current output level */ |
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pca9570_read(gpio, &gpio->out); |
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i2c_set_clientdata(client, gpio); |
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return devm_gpiochip_add_data(&client->dev, &gpio->chip, gpio); |
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} |
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static const struct i2c_device_id pca9570_id_table[] = { |
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{ "pca9570", 4 }, |
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{ /* sentinel */ } |
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}; |
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MODULE_DEVICE_TABLE(i2c, pca9570_id_table); |
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static const struct of_device_id pca9570_of_match_table[] = { |
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{ .compatible = "nxp,pca9570", .data = (void *)4 }, |
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{ /* sentinel */ } |
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}; |
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MODULE_DEVICE_TABLE(of, pca9570_of_match_table); |
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static struct i2c_driver pca9570_driver = { |
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.driver = { |
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.name = "pca9570", |
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.of_match_table = pca9570_of_match_table, |
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}, |
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.probe_new = pca9570_probe, |
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.id_table = pca9570_id_table, |
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}; |
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module_i2c_driver(pca9570_driver); |
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MODULE_AUTHOR("Sungbo Eo <[email protected]>"); |
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MODULE_DESCRIPTION("GPIO expander driver for PCA9570"); |
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MODULE_LICENSE("GPL v2");
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