cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

gpio-lp873x.c (4657B)

      1/*
      2 * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
      3 *	Keerthy <j-keerthy@ti.com>
      4 *
      5 * This program is free software; you can redistribute it and/or
      6 * modify it under the terms of the GNU General Public License version 2 as
      7 * published by the Free Software Foundation.
      8 *
      9 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
     10 * kind, whether expressed or implied; without even the implied warranty
     11 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     12 * GNU General Public License version 2 for more details.
     13 *
     14 * Based on the TPS65218 driver
     15 */
     16
     17#include <linux/gpio/driver.h>
     18#include <linux/module.h>
     19#include <linux/platform_device.h>
     20#include <linux/regmap.h>
     21
     22#include <linux/mfd/lp873x.h>
     23
     24#define BITS_PER_GPO		0x4
     25#define LP873X_GPO_CTRL_OD	0x2
     26
     27struct lp873x_gpio {
     28	struct gpio_chip chip;
     29	struct lp873x *lp873;
     30};
     31
     32static int lp873x_gpio_get_direction(struct gpio_chip *chip,
     33				     unsigned int offset)
     34{
     35	/* This device is output only */
     36	return GPIO_LINE_DIRECTION_OUT;
     37}
     38
     39static int lp873x_gpio_direction_input(struct gpio_chip *chip,
     40				       unsigned int offset)
     41{
     42	/* This device is output only */
     43	return -EINVAL;
     44}
     45
     46static int lp873x_gpio_direction_output(struct gpio_chip *chip,
     47					unsigned int offset, int value)
     48{
     49	struct lp873x_gpio *gpio = gpiochip_get_data(chip);
     50
     51	/* Set the initial value */
     52	return regmap_update_bits(gpio->lp873->regmap, LP873X_REG_GPO_CTRL,
     53				  BIT(offset * BITS_PER_GPO),
     54				  value ? BIT(offset * BITS_PER_GPO) : 0);
     55}
     56
     57static int lp873x_gpio_get(struct gpio_chip *chip, unsigned int offset)
     58{
     59	struct lp873x_gpio *gpio = gpiochip_get_data(chip);
     60	int ret, val;
     61
     62	ret = regmap_read(gpio->lp873->regmap, LP873X_REG_GPO_CTRL, &val);
     63	if (ret < 0)
     64		return ret;
     65
     66	return val & BIT(offset * BITS_PER_GPO);
     67}
     68
     69static void lp873x_gpio_set(struct gpio_chip *chip, unsigned int offset,
     70			    int value)
     71{
     72	struct lp873x_gpio *gpio = gpiochip_get_data(chip);
     73
     74	regmap_update_bits(gpio->lp873->regmap, LP873X_REG_GPO_CTRL,
     75			   BIT(offset * BITS_PER_GPO),
     76			   value ? BIT(offset * BITS_PER_GPO) : 0);
     77}
     78
     79static int lp873x_gpio_request(struct gpio_chip *gc, unsigned int offset)
     80{
     81	struct lp873x_gpio *gpio = gpiochip_get_data(gc);
     82	int ret;
     83
     84	switch (offset) {
     85	case 0:
     86		/* No MUX Set up Needed for GPO */
     87		break;
     88	case 1:
     89		/* Setup the CLKIN_PIN_SEL MUX to GPO2 */
     90		ret = regmap_update_bits(gpio->lp873->regmap, LP873X_REG_CONFIG,
     91					 LP873X_CONFIG_CLKIN_PIN_SEL, 0);
     92		if (ret)
     93			return ret;
     94
     95		break;
     96	default:
     97		return -EINVAL;
     98	}
     99
    100	return 0;
    101}
    102
    103static int lp873x_gpio_set_config(struct gpio_chip *gc, unsigned offset,
    104				  unsigned long config)
    105{
    106	struct lp873x_gpio *gpio = gpiochip_get_data(gc);
    107
    108	switch (pinconf_to_config_param(config)) {
    109	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
    110		return regmap_update_bits(gpio->lp873->regmap,
    111					  LP873X_REG_GPO_CTRL,
    112					  BIT(offset * BITS_PER_GPO +
    113					  LP873X_GPO_CTRL_OD),
    114					  BIT(offset * BITS_PER_GPO +
    115					  LP873X_GPO_CTRL_OD));
    116
    117	case PIN_CONFIG_DRIVE_PUSH_PULL:
    118		return regmap_update_bits(gpio->lp873->regmap,
    119					  LP873X_REG_GPO_CTRL,
    120					  BIT(offset * BITS_PER_GPO +
    121					  LP873X_GPO_CTRL_OD), 0);
    122	default:
    123		return -ENOTSUPP;
    124	}
    125}
    126
    127static const struct gpio_chip template_chip = {
    128	.label			= "lp873x-gpio",
    129	.owner			= THIS_MODULE,
    130	.request		= lp873x_gpio_request,
    131	.get_direction		= lp873x_gpio_get_direction,
    132	.direction_input	= lp873x_gpio_direction_input,
    133	.direction_output	= lp873x_gpio_direction_output,
    134	.get			= lp873x_gpio_get,
    135	.set			= lp873x_gpio_set,
    136	.set_config		= lp873x_gpio_set_config,
    137	.base			= -1,
    138	.ngpio			= 2,
    139	.can_sleep		= true,
    140};
    141
    142static int lp873x_gpio_probe(struct platform_device *pdev)
    143{
    144	struct lp873x_gpio *gpio;
    145	int ret;
    146
    147	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
    148	if (!gpio)
    149		return -ENOMEM;
    150
    151	platform_set_drvdata(pdev, gpio);
    152
    153	gpio->lp873 = dev_get_drvdata(pdev->dev.parent);
    154	gpio->chip = template_chip;
    155	gpio->chip.parent = gpio->lp873->dev;
    156
    157	ret = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
    158	if (ret < 0) {
    159		dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
    160		return ret;
    161	}
    162
    163	return 0;
    164}
    165
    166static const struct platform_device_id lp873x_gpio_id_table[] = {
    167	{ "lp873x-gpio", },
    168	{ /* sentinel */ }
    169};
    170MODULE_DEVICE_TABLE(platform, lp873x_gpio_id_table);
    171
    172static struct platform_driver lp873x_gpio_driver = {
    173	.driver = {
    174		.name = "lp873x-gpio",
    175	},
    176	.probe = lp873x_gpio_probe,
    177	.id_table = lp873x_gpio_id_table,
    178};
    179module_platform_driver(lp873x_gpio_driver);
    180
    181MODULE_AUTHOR("Keerthy <j-keerthy@ti.com>");
    182MODULE_DESCRIPTION("LP873X GPIO driver");
    183MODULE_LICENSE("GPL v2");