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kernel-fxtec-pro1x/drivers/gpio/gpio-syscon.c
Grygorii Strashko 2134cb997f gpio: syscon: reuse for keystone 2 socs 
On Keystone SOCs, ARM host can send interrupts to DSP cores using the
DSP GPIO controller IP. Each DSP GPIO controller provides 28 IRQ signals for
each DSP core. This is one of the component used by the IPC mechanism used
on Keystone SOCs.

Keystone 2 DSP GPIO controller has specific features:
- each GPIO can be configured only as output pin;
- setting GPIO value to 1 causes IRQ generation on target DSP core;
- reading pin value returns 0 - if IRQ was handled or 1 - IRQ is still
  pending.

This patch updates gpio-syscon driver to be reused by Keystone 2 SoCs,
because the Keystone 2 DSP GPIO controller is controlled through Syscon
devices and, as requested by Linus Walleij, such kind of GPIO controllers
should be integrated with drivers/gpio/gpio-syscon.c driver.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-09-16 14:42:16 -07:00

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/*
* SYSCON GPIO driver
*
* Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#define GPIO_SYSCON_FEAT_IN BIT(0)
#define GPIO_SYSCON_FEAT_OUT BIT(1)
#define GPIO_SYSCON_FEAT_DIR BIT(2)
/* SYSCON driver is designed to use 32-bit wide registers */
#define SYSCON_REG_SIZE (4)
#define SYSCON_REG_BITS (SYSCON_REG_SIZE * 8)
/**
* struct syscon_gpio_data - Configuration for the device.
* compatible: SYSCON driver compatible string.
* flags: Set of GPIO_SYSCON_FEAT_ flags:
* GPIO_SYSCON_FEAT_IN: GPIOs supports input,
* GPIO_SYSCON_FEAT_OUT: GPIOs supports output,
* GPIO_SYSCON_FEAT_DIR: GPIOs supports switch direction.
* bit_count: Number of bits used as GPIOs.
* dat_bit_offset: Offset (in bits) to the first GPIO bit.
* dir_bit_offset: Optional offset (in bits) to the first bit to switch
* GPIO direction (Used with GPIO_SYSCON_FEAT_DIR flag).
* set: HW specific callback to assigns output value
* for signal "offset"
*/
struct syscon_gpio_data {
const char *compatible;
unsigned int flags;
unsigned int bit_count;
unsigned int dat_bit_offset;
unsigned int dir_bit_offset;
void (*set)(struct gpio_chip *chip,
unsigned offset, int value);
};
struct syscon_gpio_priv {
struct gpio_chip chip;
struct regmap *syscon;
const struct syscon_gpio_data *data;
u32 dreg_offset;
u32 dir_reg_offset;
};
static inline struct syscon_gpio_priv *to_syscon_gpio(struct gpio_chip *chip)
{
return container_of(chip, struct syscon_gpio_priv, chip);
}
static int syscon_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct syscon_gpio_priv *priv = to_syscon_gpio(chip);
unsigned int val, offs;
int ret;
offs = priv->dreg_offset + priv->data->dat_bit_offset + offset;
ret = regmap_read(priv->syscon,
(offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE, &val);
if (ret)
return ret;
return !!(val & BIT(offs % SYSCON_REG_BITS));
}
static void syscon_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
{
struct syscon_gpio_priv *priv = to_syscon_gpio(chip);
unsigned int offs;
offs = priv->dreg_offset + priv->data->dat_bit_offset + offset;
regmap_update_bits(priv->syscon,
(offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
BIT(offs % SYSCON_REG_BITS),
val ? BIT(offs % SYSCON_REG_BITS) : 0);
}
static int syscon_gpio_dir_in(struct gpio_chip *chip, unsigned offset)
{
struct syscon_gpio_priv *priv = to_syscon_gpio(chip);
if (priv->data->flags & GPIO_SYSCON_FEAT_DIR) {
unsigned int offs;
offs = priv->dir_reg_offset +
priv->data->dir_bit_offset + offset;
regmap_update_bits(priv->syscon,
(offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
BIT(offs % SYSCON_REG_BITS), 0);
}
return 0;
}
static int syscon_gpio_dir_out(struct gpio_chip *chip, unsigned offset, int val)
{
struct syscon_gpio_priv *priv = to_syscon_gpio(chip);
if (priv->data->flags & GPIO_SYSCON_FEAT_DIR) {
unsigned int offs;
offs = priv->dir_reg_offset +
priv->data->dir_bit_offset + offset;
regmap_update_bits(priv->syscon,
(offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
BIT(offs % SYSCON_REG_BITS),
BIT(offs % SYSCON_REG_BITS));
}
priv->data->set(chip, offset, val);
return 0;
}
static const struct syscon_gpio_data clps711x_mctrl_gpio = {
/* ARM CLPS711X SYSFLG1 Bits 8-10 */
.compatible = "cirrus,clps711x-syscon1",
.flags = GPIO_SYSCON_FEAT_IN,
.bit_count = 3,
.dat_bit_offset = 0x40 * 8 + 8,
};
#define KEYSTONE_LOCK_BIT BIT(0)
static void keystone_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
{
struct syscon_gpio_priv *priv = to_syscon_gpio(chip);
unsigned int offs;
int ret;
offs = priv->dreg_offset + priv->data->dat_bit_offset + offset;
if (!val)
return;
ret = regmap_update_bits(
priv->syscon,
(offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
BIT(offs % SYSCON_REG_BITS) | KEYSTONE_LOCK_BIT,
BIT(offs % SYSCON_REG_BITS) | KEYSTONE_LOCK_BIT);
if (ret < 0)
dev_err(chip->dev, "gpio write failed ret(%d)\n", ret);
}
static const struct syscon_gpio_data keystone_dsp_gpio = {
/* ARM Keystone 2 */
.compatible = NULL,
.flags = GPIO_SYSCON_FEAT_OUT,
.bit_count = 28,
.dat_bit_offset = 4,
.set = keystone_gpio_set,
};
static const struct of_device_id syscon_gpio_ids[] = {
{
.compatible = "cirrus,clps711x-mctrl-gpio",
.data = &clps711x_mctrl_gpio,
},
{
.compatible = "ti,keystone-dsp-gpio",
.data = &keystone_dsp_gpio,
},
{ }
};
MODULE_DEVICE_TABLE(of, syscon_gpio_ids);
static int syscon_gpio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
const struct of_device_id *of_id = of_match_device(syscon_gpio_ids, dev);
struct syscon_gpio_priv *priv;
struct device_node *np = dev->of_node;
int ret;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->data = of_id->data;
if (priv->data->compatible) {
priv->syscon = syscon_regmap_lookup_by_compatible(
priv->data->compatible);
if (IS_ERR(priv->syscon))
return PTR_ERR(priv->syscon);
} else {
priv->syscon =
syscon_regmap_lookup_by_phandle(np, "gpio,syscon-dev");
if (IS_ERR(priv->syscon))
return PTR_ERR(priv->syscon);
ret = of_property_read_u32_index(np, "gpio,syscon-dev", 1,
&priv->dreg_offset);
if (ret)
dev_err(dev, "can't read the data register offset!\n");
priv->dreg_offset <<= 3;
ret = of_property_read_u32_index(np, "gpio,syscon-dev", 2,
&priv->dir_reg_offset);
if (ret)
dev_err(dev, "can't read the dir register offset!\n");
priv->dir_reg_offset <<= 3;
}
priv->chip.dev = dev;
priv->chip.owner = THIS_MODULE;
priv->chip.label = dev_name(dev);
priv->chip.base = -1;
priv->chip.ngpio = priv->data->bit_count;
priv->chip.get = syscon_gpio_get;
if (priv->data->flags & GPIO_SYSCON_FEAT_IN)
priv->chip.direction_input = syscon_gpio_dir_in;
if (priv->data->flags & GPIO_SYSCON_FEAT_OUT) {
priv->chip.set = priv->data->set ? : syscon_gpio_set;
priv->chip.direction_output = syscon_gpio_dir_out;
}
platform_set_drvdata(pdev, priv);
return gpiochip_add(&priv->chip);
}
static int syscon_gpio_remove(struct platform_device *pdev)
{
struct syscon_gpio_priv *priv = platform_get_drvdata(pdev);
gpiochip_remove(&priv->chip);
return 0;
}
static struct platform_driver syscon_gpio_driver = {
.driver = {
.name = "gpio-syscon",
.owner = THIS_MODULE,
.of_match_table = syscon_gpio_ids,
},
.probe = syscon_gpio_probe,
.remove = syscon_gpio_remove,
};
module_platform_driver(syscon_gpio_driver);
MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
MODULE_DESCRIPTION("SYSCON GPIO driver");
MODULE_LICENSE("GPL");
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