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ba74bd5d5b
The gpiolib cannot deduce the fact that every line is output by itself, implement a .get_direction() callback so we can inspect this. Acked-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
120 lines
2.8 KiB
C
120 lines
2.8 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Access to GPOs on TWL6040 chip
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*
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* Copyright (C) 2012 Texas Instruments, Inc.
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*
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* Authors:
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* Sergio Aguirre <saaguirre@ti.com>
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* Peter Ujfalusi <peter.ujfalusi@ti.com>
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/kthread.h>
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#include <linux/irq.h>
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#include <linux/gpio/driver.h>
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#include <linux/platform_device.h>
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#include <linux/bitops.h>
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#include <linux/of.h>
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#include <linux/mfd/twl6040.h>
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static int twl6040gpo_get(struct gpio_chip *chip, unsigned offset)
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{
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struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
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int ret = 0;
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ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
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if (ret < 0)
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return ret;
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return !!(ret & BIT(offset));
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}
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static int twl6040gpo_get_direction(struct gpio_chip *chip, unsigned offset)
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{
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/* This means "out" */
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return 0;
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}
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static int twl6040gpo_direction_out(struct gpio_chip *chip, unsigned offset,
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int value)
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{
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/* This only drives GPOs, and can't change direction */
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return 0;
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}
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static void twl6040gpo_set(struct gpio_chip *chip, unsigned offset, int value)
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{
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struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
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int ret;
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u8 gpoctl;
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ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
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if (ret < 0)
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return;
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if (value)
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gpoctl = ret | BIT(offset);
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else
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gpoctl = ret & ~BIT(offset);
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twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, gpoctl);
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}
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static struct gpio_chip twl6040gpo_chip = {
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.label = "twl6040",
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.owner = THIS_MODULE,
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.get = twl6040gpo_get,
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.direction_output = twl6040gpo_direction_out,
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.get_direction = twl6040gpo_get_direction,
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.set = twl6040gpo_set,
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.can_sleep = true,
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};
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/*----------------------------------------------------------------------*/
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static int gpo_twl6040_probe(struct platform_device *pdev)
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{
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struct device *twl6040_core_dev = pdev->dev.parent;
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struct twl6040 *twl6040 = dev_get_drvdata(twl6040_core_dev);
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int ret;
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twl6040gpo_chip.base = -1;
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if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
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twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
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else
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twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */
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twl6040gpo_chip.parent = &pdev->dev;
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#ifdef CONFIG_OF_GPIO
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twl6040gpo_chip.of_node = twl6040_core_dev->of_node;
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#endif
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ret = devm_gpiochip_add_data(&pdev->dev, &twl6040gpo_chip, NULL);
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if (ret < 0) {
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dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
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twl6040gpo_chip.ngpio = 0;
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}
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return ret;
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}
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/* Note: this hardware lives inside an I2C-based multi-function device. */
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MODULE_ALIAS("platform:twl6040-gpo");
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static struct platform_driver gpo_twl6040_driver = {
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.driver = {
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.name = "twl6040-gpo",
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},
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.probe = gpo_twl6040_probe,
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};
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module_platform_driver(gpo_twl6040_driver);
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MODULE_AUTHOR("Texas Instruments, Inc.");
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MODULE_DESCRIPTION("GPO interface for TWL6040");
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MODULE_LICENSE("GPL");
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