gpio-twl6040.c

  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Access to GPOs on TWL6040 chip
  4 *
  5 * Copyright (C) 2012 Texas Instruments, Inc.
  6 *
  7 * Authors:
  8 *	Sergio Aguirre <saaguirre@ti.com>
  9 *	Peter Ujfalusi <peter.ujfalusi@ti.com>
 10 */
 11
 12#include <linux/module.h>
 13#include <linux/init.h>
 14#include <linux/kthread.h>
 15#include <linux/irq.h>
 16#include <linux/gpio/driver.h>
 17#include <linux/platform_device.h>
 18#include <linux/bitops.h>
 19#include <linux/of.h>
 20
 21#include <linux/mfd/twl6040.h>
 22
 23static int twl6040gpo_get(struct gpio_chip *chip, unsigned offset)
 24{
 25	struct twl6040 *twl6040 = gpiochip_get_data(chip);
 26	int ret = 0;
 27
 28	ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
 29	if (ret < 0)
 30		return ret;
 31
 32	return !!(ret & BIT(offset));
 33}
 34
 35static int twl6040gpo_get_direction(struct gpio_chip *chip, unsigned offset)
 36{
 37	return GPIO_LINE_DIRECTION_OUT;
 38}
 39
 40static int twl6040gpo_set(struct gpio_chip *chip, unsigned int offset,
 41			  int value)
 42{
 43	struct twl6040 *twl6040 = gpiochip_get_data(chip);
 44	int ret;
 45	u8 gpoctl;
 46
 47	ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
 48	if (ret < 0)
 49		return ret;
 50
 51	if (value)
 52		gpoctl = ret | BIT(offset);
 53	else
 54		gpoctl = ret & ~BIT(offset);
 55
 56	return twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, gpoctl);
 57}
 58
 59static int twl6040gpo_direction_out(struct gpio_chip *chip, unsigned int offset,
 60				    int value)
 61{
 62	/* This only drives GPOs, and can't change direction */
 63	return twl6040gpo_set(chip, offset, value);
 64}
 65
 66static struct gpio_chip twl6040gpo_chip = {
 67	.label			= "twl6040",
 68	.owner			= THIS_MODULE,
 69	.get			= twl6040gpo_get,
 70	.direction_output	= twl6040gpo_direction_out,
 71	.get_direction		= twl6040gpo_get_direction,
 72	.set			= twl6040gpo_set,
 73	.can_sleep		= true,
 74};
 75
 76/*----------------------------------------------------------------------*/
 77
 78static int gpo_twl6040_probe(struct platform_device *pdev)
 79{
 80	struct device *twl6040_core_dev = pdev->dev.parent;
 81	struct twl6040 *twl6040 = dev_get_drvdata(twl6040_core_dev);
 82	int ret;
 83
 84	device_set_node(&pdev->dev, dev_fwnode(pdev->dev.parent));
 85
 86	twl6040gpo_chip.base = -1;
 87
 88	if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
 89		twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
 90	else
 91		twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */
 92
 93	twl6040gpo_chip.parent = &pdev->dev;
 94
 95	ret = devm_gpiochip_add_data(&pdev->dev, &twl6040gpo_chip, twl6040);
 96	if (ret < 0) {
 97		dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
 98		twl6040gpo_chip.ngpio = 0;
 99	}
100
101	return ret;
102}
103
104/* Note:  this hardware lives inside an I2C-based multi-function device. */
105MODULE_ALIAS("platform:twl6040-gpo");
106
107static struct platform_driver gpo_twl6040_driver = {
108	.driver = {
109		.name	= "twl6040-gpo",
110	},
111	.probe		= gpo_twl6040_probe,
112};
113
114module_platform_driver(gpo_twl6040_driver);
115
116MODULE_AUTHOR("Texas Instruments, Inc.");
117MODULE_DESCRIPTION("GPO interface for TWL6040");
118MODULE_LICENSE("GPL");