linux-stable/drivers/gpio/gpio-kempld.c
Thomas Gleixner 9f8068503d treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 294
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license 2 as published
  by the free software foundation this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation this program is distributed in the hope
  that it [would] be useful but without any warranty without even the
  implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 9 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.804956444@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:36:38 +02:00

197 lines
5 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Kontron PLD GPIO driver
*
* Copyright (c) 2010-2013 Kontron Europe GmbH
* Author: Michael Brunner <michael.brunner@kontron.com>
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/platform_device.h>
#include <linux/gpio/driver.h>
#include <linux/mfd/kempld.h>
#define KEMPLD_GPIO_MAX_NUM 16
#define KEMPLD_GPIO_MASK(x) (BIT((x) % 8))
#define KEMPLD_GPIO_DIR_NUM(x) (0x40 + (x) / 8)
#define KEMPLD_GPIO_LVL_NUM(x) (0x42 + (x) / 8)
#define KEMPLD_GPIO_EVT_LVL_EDGE 0x46
#define KEMPLD_GPIO_IEN 0x4A
struct kempld_gpio_data {
struct gpio_chip chip;
struct kempld_device_data *pld;
};
/*
* Set or clear GPIO bit
* kempld_get_mutex must be called prior to calling this function.
*/
static void kempld_gpio_bitop(struct kempld_device_data *pld,
u8 reg, u8 bit, u8 val)
{
u8 status;
status = kempld_read8(pld, reg);
if (val)
status |= KEMPLD_GPIO_MASK(bit);
else
status &= ~KEMPLD_GPIO_MASK(bit);
kempld_write8(pld, reg, status);
}
static int kempld_gpio_get_bit(struct kempld_device_data *pld, u8 reg, u8 bit)
{
u8 status;
kempld_get_mutex(pld);
status = kempld_read8(pld, reg);
kempld_release_mutex(pld);
return !!(status & KEMPLD_GPIO_MASK(bit));
}
static int kempld_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
struct kempld_device_data *pld = gpio->pld;
return !!kempld_gpio_get_bit(pld, KEMPLD_GPIO_LVL_NUM(offset), offset);
}
static void kempld_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
struct kempld_device_data *pld = gpio->pld;
kempld_get_mutex(pld);
kempld_gpio_bitop(pld, KEMPLD_GPIO_LVL_NUM(offset), offset, value);
kempld_release_mutex(pld);
}
static int kempld_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
struct kempld_device_data *pld = gpio->pld;
kempld_get_mutex(pld);
kempld_gpio_bitop(pld, KEMPLD_GPIO_DIR_NUM(offset), offset, 0);
kempld_release_mutex(pld);
return 0;
}
static int kempld_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
int value)
{
struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
struct kempld_device_data *pld = gpio->pld;
kempld_get_mutex(pld);
kempld_gpio_bitop(pld, KEMPLD_GPIO_LVL_NUM(offset), offset, value);
kempld_gpio_bitop(pld, KEMPLD_GPIO_DIR_NUM(offset), offset, 1);
kempld_release_mutex(pld);
return 0;
}
static int kempld_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
{
struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
struct kempld_device_data *pld = gpio->pld;
return !kempld_gpio_get_bit(pld, KEMPLD_GPIO_DIR_NUM(offset), offset);
}
static int kempld_gpio_pincount(struct kempld_device_data *pld)
{
u16 evt, evt_back;
kempld_get_mutex(pld);
/* Backup event register as it might be already initialized */
evt_back = kempld_read16(pld, KEMPLD_GPIO_EVT_LVL_EDGE);
/* Clear event register */
kempld_write16(pld, KEMPLD_GPIO_EVT_LVL_EDGE, 0x0000);
/* Read back event register */
evt = kempld_read16(pld, KEMPLD_GPIO_EVT_LVL_EDGE);
/* Restore event register */
kempld_write16(pld, KEMPLD_GPIO_EVT_LVL_EDGE, evt_back);
kempld_release_mutex(pld);
return evt ? __ffs(evt) : 16;
}
static int kempld_gpio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct kempld_device_data *pld = dev_get_drvdata(dev->parent);
struct kempld_platform_data *pdata = dev_get_platdata(pld->dev);
struct kempld_gpio_data *gpio;
struct gpio_chip *chip;
int ret;
if (pld->info.spec_major < 2) {
dev_err(dev,
"Driver only supports GPIO devices compatible to PLD spec. rev. 2.0 or higher\n");
return -ENODEV;
}
gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
if (!gpio)
return -ENOMEM;
gpio->pld = pld;
platform_set_drvdata(pdev, gpio);
chip = &gpio->chip;
chip->label = "gpio-kempld";
chip->owner = THIS_MODULE;
chip->parent = dev;
chip->can_sleep = true;
if (pdata && pdata->gpio_base)
chip->base = pdata->gpio_base;
else
chip->base = -1;
chip->direction_input = kempld_gpio_direction_input;
chip->direction_output = kempld_gpio_direction_output;
chip->get_direction = kempld_gpio_get_direction;
chip->get = kempld_gpio_get;
chip->set = kempld_gpio_set;
chip->ngpio = kempld_gpio_pincount(pld);
if (chip->ngpio == 0) {
dev_err(dev, "No GPIO pins detected\n");
return -ENODEV;
}
ret = devm_gpiochip_add_data(dev, chip, gpio);
if (ret) {
dev_err(dev, "Could not register GPIO chip\n");
return ret;
}
dev_info(dev, "GPIO functionality initialized with %d pins\n",
chip->ngpio);
return 0;
}
static struct platform_driver kempld_gpio_driver = {
.driver = {
.name = "kempld-gpio",
},
.probe = kempld_gpio_probe,
};
module_platform_driver(kempld_gpio_driver);
MODULE_DESCRIPTION("KEM PLD GPIO Driver");
MODULE_AUTHOR("Michael Brunner <michael.brunner@kontron.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:kempld-gpio");