cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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gpio-twl6040.c (2830B)

      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 = dev_get_drvdata(chip->parent->parent);
     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_direction_out(struct gpio_chip *chip, unsigned offset,
     41				    int value)
     42{
     43	/* This only drives GPOs, and can't change direction */
     44	return 0;
     45}
     46
     47static void twl6040gpo_set(struct gpio_chip *chip, unsigned offset, int value)
     48{
     49	struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
     50	int ret;
     51	u8 gpoctl;
     52
     53	ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
     54	if (ret < 0)
     55		return;
     56
     57	if (value)
     58		gpoctl = ret | BIT(offset);
     59	else
     60		gpoctl = ret & ~BIT(offset);
     61
     62	twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, gpoctl);
     63}
     64
     65static struct gpio_chip twl6040gpo_chip = {
     66	.label			= "twl6040",
     67	.owner			= THIS_MODULE,
     68	.get			= twl6040gpo_get,
     69	.direction_output	= twl6040gpo_direction_out,
     70	.get_direction		= twl6040gpo_get_direction,
     71	.set			= twl6040gpo_set,
     72	.can_sleep		= true,
     73};
     74
     75/*----------------------------------------------------------------------*/
     76
     77static int gpo_twl6040_probe(struct platform_device *pdev)
     78{
     79	struct device *twl6040_core_dev = pdev->dev.parent;
     80	struct twl6040 *twl6040 = dev_get_drvdata(twl6040_core_dev);
     81	int ret;
     82
     83	device_set_node(&pdev->dev, dev_fwnode(pdev->dev.parent));
     84
     85	twl6040gpo_chip.base = -1;
     86
     87	if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
     88		twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
     89	else
     90		twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */
     91
     92	twl6040gpo_chip.parent = &pdev->dev;
     93
     94	ret = devm_gpiochip_add_data(&pdev->dev, &twl6040gpo_chip, NULL);
     95	if (ret < 0) {
     96		dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
     97		twl6040gpo_chip.ngpio = 0;
     98	}
     99
    100	return ret;
    101}
    102
    103/* Note:  this hardware lives inside an I2C-based multi-function device. */
    104MODULE_ALIAS("platform:twl6040-gpo");
    105
    106static struct platform_driver gpo_twl6040_driver = {
    107	.driver = {
    108		.name	= "twl6040-gpo",
    109	},
    110	.probe		= gpo_twl6040_probe,
    111};
    112
    113module_platform_driver(gpo_twl6040_driver);
    114
    115MODULE_AUTHOR("Texas Instruments, Inc.");
    116MODULE_DESCRIPTION("GPO interface for TWL6040");
    117MODULE_LICENSE("GPL");