forked from Minki/linux
448cf90513
GPIO library does copy the of_node from the parent device of the GPIO chip, there is no need to repeat this in the individual drivers. Remove these assignment all at once. For the details one may look into the of_gpio_dev_init() implementation. While at it, remove duplicate parent device assignment where it is the case. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-By: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
137 lines
3.1 KiB
C
137 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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//
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// Gateworks I2C PLD GPIO expander
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//
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// Copyright (C) 2019 Linus Walleij <linus.walleij@linaro.org>
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//
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// Based on code and know-how from the OpenWrt driver:
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// Copyright (C) 2009 Gateworks Corporation
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// Authors: Chris Lang, Imre Kaloz
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#include <linux/bits.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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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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/**
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* struct gw_pld - State container for Gateworks PLD
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* @chip: GPIO chip instance
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* @client: I2C client
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* @out: shadow register for the output bute
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*/
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struct gw_pld {
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struct gpio_chip chip;
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struct i2c_client *client;
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u8 out;
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};
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/*
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* The Gateworks I2C PLD chip only expose one read and one write register.
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* Writing a "one" bit (to match the reset state) lets that pin be used as an
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* input. It is an open-drain model.
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*/
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static int gw_pld_input8(struct gpio_chip *gc, unsigned offset)
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{
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struct gw_pld *gw = gpiochip_get_data(gc);
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gw->out |= BIT(offset);
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return i2c_smbus_write_byte(gw->client, gw->out);
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}
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static int gw_pld_get8(struct gpio_chip *gc, unsigned offset)
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{
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struct gw_pld *gw = gpiochip_get_data(gc);
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s32 val;
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val = i2c_smbus_read_byte(gw->client);
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return (val < 0) ? 0 : !!(val & BIT(offset));
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}
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static int gw_pld_output8(struct gpio_chip *gc, unsigned offset, int value)
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{
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struct gw_pld *gw = gpiochip_get_data(gc);
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if (value)
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gw->out |= BIT(offset);
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else
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gw->out &= ~BIT(offset);
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return i2c_smbus_write_byte(gw->client, gw->out);
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}
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static void gw_pld_set8(struct gpio_chip *gc, unsigned offset, int value)
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{
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gw_pld_output8(gc, offset, value);
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}
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static int gw_pld_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct device *dev = &client->dev;
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struct device_node *np = dev->of_node;
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struct gw_pld *gw;
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int ret;
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gw = devm_kzalloc(dev, sizeof(*gw), GFP_KERNEL);
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if (!gw)
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return -ENOMEM;
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gw->chip.base = -1;
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gw->chip.can_sleep = true;
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gw->chip.parent = dev;
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gw->chip.owner = THIS_MODULE;
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gw->chip.label = dev_name(dev);
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gw->chip.ngpio = 8;
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gw->chip.direction_input = gw_pld_input8;
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gw->chip.get = gw_pld_get8;
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gw->chip.direction_output = gw_pld_output8;
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gw->chip.set = gw_pld_set8;
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gw->client = client;
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/*
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* The Gateworks I2C PLD chip does not properly send the acknowledge
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* bit at all times, but we can still use the standard i2c_smbus
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* functions by simply ignoring this bit.
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*/
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client->flags |= I2C_M_IGNORE_NAK;
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gw->out = 0xFF;
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i2c_set_clientdata(client, gw);
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ret = devm_gpiochip_add_data(dev, &gw->chip, gw);
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if (ret)
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return ret;
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dev_info(dev, "registered Gateworks PLD GPIO device\n");
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return 0;
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}
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static const struct i2c_device_id gw_pld_id[] = {
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{ "gw-pld", },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, gw_pld_id);
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static const struct of_device_id gw_pld_dt_ids[] = {
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{ .compatible = "gateworks,pld-gpio", },
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{ },
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};
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MODULE_DEVICE_TABLE(of, gw_pld_dt_ids);
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static struct i2c_driver gw_pld_driver = {
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.driver = {
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.name = "gw_pld",
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.of_match_table = gw_pld_dt_ids,
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},
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.probe = gw_pld_probe,
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.id_table = gw_pld_id,
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};
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module_i2c_driver(gw_pld_driver);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
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