70728c2946
The priv->data->set can be NULL while flags contains GPIO_SYSCON_FEAT_OUT and chip->set is valid pointer. This happens in case the controller uses the default GPIO setter. Always use chip->set to access the setter to avoid possible NULL pointer dereferencing. Signed-off-by: Marek Vasut <marex@denx.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
284 lines
7.5 KiB
C
284 lines
7.5 KiB
C
/*
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* SYSCON GPIO driver
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*
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* Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/err.h>
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#include <linux/gpio/driver.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/platform_device.h>
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#include <linux/regmap.h>
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#include <linux/mfd/syscon.h>
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#define GPIO_SYSCON_FEAT_IN BIT(0)
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#define GPIO_SYSCON_FEAT_OUT BIT(1)
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#define GPIO_SYSCON_FEAT_DIR BIT(2)
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/* SYSCON driver is designed to use 32-bit wide registers */
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#define SYSCON_REG_SIZE (4)
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#define SYSCON_REG_BITS (SYSCON_REG_SIZE * 8)
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/**
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* struct syscon_gpio_data - Configuration for the device.
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* compatible: SYSCON driver compatible string.
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* flags: Set of GPIO_SYSCON_FEAT_ flags:
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* GPIO_SYSCON_FEAT_IN: GPIOs supports input,
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* GPIO_SYSCON_FEAT_OUT: GPIOs supports output,
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* GPIO_SYSCON_FEAT_DIR: GPIOs supports switch direction.
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* bit_count: Number of bits used as GPIOs.
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* dat_bit_offset: Offset (in bits) to the first GPIO bit.
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* dir_bit_offset: Optional offset (in bits) to the first bit to switch
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* GPIO direction (Used with GPIO_SYSCON_FEAT_DIR flag).
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* set: HW specific callback to assigns output value
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* for signal "offset"
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*/
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struct syscon_gpio_data {
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const char *compatible;
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unsigned int flags;
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unsigned int bit_count;
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unsigned int dat_bit_offset;
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unsigned int dir_bit_offset;
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void (*set)(struct gpio_chip *chip,
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unsigned offset, int value);
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};
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struct syscon_gpio_priv {
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struct gpio_chip chip;
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struct regmap *syscon;
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const struct syscon_gpio_data *data;
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u32 dreg_offset;
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u32 dir_reg_offset;
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};
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static int syscon_gpio_get(struct gpio_chip *chip, unsigned offset)
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{
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struct syscon_gpio_priv *priv = gpiochip_get_data(chip);
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unsigned int val, offs;
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int ret;
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offs = priv->dreg_offset + priv->data->dat_bit_offset + offset;
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ret = regmap_read(priv->syscon,
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(offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE, &val);
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if (ret)
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return ret;
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return !!(val & BIT(offs % SYSCON_REG_BITS));
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}
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static void syscon_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
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{
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struct syscon_gpio_priv *priv = gpiochip_get_data(chip);
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unsigned int offs;
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offs = priv->dreg_offset + priv->data->dat_bit_offset + offset;
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regmap_update_bits(priv->syscon,
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(offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
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BIT(offs % SYSCON_REG_BITS),
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val ? BIT(offs % SYSCON_REG_BITS) : 0);
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}
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static int syscon_gpio_dir_in(struct gpio_chip *chip, unsigned offset)
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{
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struct syscon_gpio_priv *priv = gpiochip_get_data(chip);
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if (priv->data->flags & GPIO_SYSCON_FEAT_DIR) {
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unsigned int offs;
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offs = priv->dir_reg_offset +
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priv->data->dir_bit_offset + offset;
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regmap_update_bits(priv->syscon,
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(offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
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BIT(offs % SYSCON_REG_BITS), 0);
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}
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return 0;
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}
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static int syscon_gpio_dir_out(struct gpio_chip *chip, unsigned offset, int val)
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{
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struct syscon_gpio_priv *priv = gpiochip_get_data(chip);
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if (priv->data->flags & GPIO_SYSCON_FEAT_DIR) {
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unsigned int offs;
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offs = priv->dir_reg_offset +
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priv->data->dir_bit_offset + offset;
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regmap_update_bits(priv->syscon,
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(offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
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BIT(offs % SYSCON_REG_BITS),
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BIT(offs % SYSCON_REG_BITS));
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}
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chip->set(chip, offset, val);
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return 0;
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}
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static const struct syscon_gpio_data clps711x_mctrl_gpio = {
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/* ARM CLPS711X SYSFLG1 Bits 8-10 */
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.compatible = "cirrus,ep7209-syscon1",
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.flags = GPIO_SYSCON_FEAT_IN,
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.bit_count = 3,
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.dat_bit_offset = 0x40 * 8 + 8,
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};
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static void rockchip_gpio_set(struct gpio_chip *chip, unsigned int offset,
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int val)
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{
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struct syscon_gpio_priv *priv = gpiochip_get_data(chip);
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unsigned int offs;
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u8 bit;
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u32 data;
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int ret;
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offs = priv->dreg_offset + priv->data->dat_bit_offset + offset;
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bit = offs % SYSCON_REG_BITS;
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data = (val ? BIT(bit) : 0) | BIT(bit + 16);
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ret = regmap_write(priv->syscon,
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(offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
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data);
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if (ret < 0)
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dev_err(chip->parent, "gpio write failed ret(%d)\n", ret);
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}
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static const struct syscon_gpio_data rockchip_rk3328_gpio_mute = {
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/* RK3328 GPIO_MUTE is an output only pin at GRF_SOC_CON10[1] */
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.flags = GPIO_SYSCON_FEAT_OUT,
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.bit_count = 1,
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.dat_bit_offset = 0x0428 * 8 + 1,
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.set = rockchip_gpio_set,
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};
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#define KEYSTONE_LOCK_BIT BIT(0)
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static void keystone_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
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{
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struct syscon_gpio_priv *priv = gpiochip_get_data(chip);
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unsigned int offs;
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int ret;
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offs = priv->dreg_offset + priv->data->dat_bit_offset + offset;
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if (!val)
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return;
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ret = regmap_update_bits(
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priv->syscon,
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(offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
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BIT(offs % SYSCON_REG_BITS) | KEYSTONE_LOCK_BIT,
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BIT(offs % SYSCON_REG_BITS) | KEYSTONE_LOCK_BIT);
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if (ret < 0)
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dev_err(chip->parent, "gpio write failed ret(%d)\n", ret);
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}
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static const struct syscon_gpio_data keystone_dsp_gpio = {
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/* ARM Keystone 2 */
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.compatible = NULL,
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.flags = GPIO_SYSCON_FEAT_OUT,
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.bit_count = 28,
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.dat_bit_offset = 4,
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.set = keystone_gpio_set,
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};
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static const struct of_device_id syscon_gpio_ids[] = {
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{
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.compatible = "cirrus,ep7209-mctrl-gpio",
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.data = &clps711x_mctrl_gpio,
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},
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{
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.compatible = "ti,keystone-dsp-gpio",
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.data = &keystone_dsp_gpio,
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},
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{
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.compatible = "rockchip,rk3328-grf-gpio",
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.data = &rockchip_rk3328_gpio_mute,
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},
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{ }
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};
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MODULE_DEVICE_TABLE(of, syscon_gpio_ids);
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static int syscon_gpio_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct syscon_gpio_priv *priv;
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struct device_node *np = dev->of_node;
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int ret;
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priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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priv->data = of_device_get_match_data(dev);
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if (priv->data->compatible) {
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priv->syscon = syscon_regmap_lookup_by_compatible(
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priv->data->compatible);
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if (IS_ERR(priv->syscon))
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return PTR_ERR(priv->syscon);
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} else {
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priv->syscon =
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syscon_regmap_lookup_by_phandle(np, "gpio,syscon-dev");
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if (IS_ERR(priv->syscon) && np->parent)
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priv->syscon = syscon_node_to_regmap(np->parent);
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if (IS_ERR(priv->syscon))
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return PTR_ERR(priv->syscon);
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ret = of_property_read_u32_index(np, "gpio,syscon-dev", 1,
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&priv->dreg_offset);
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if (ret)
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dev_err(dev, "can't read the data register offset!\n");
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priv->dreg_offset <<= 3;
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ret = of_property_read_u32_index(np, "gpio,syscon-dev", 2,
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&priv->dir_reg_offset);
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if (ret)
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dev_dbg(dev, "can't read the dir register offset!\n");
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priv->dir_reg_offset <<= 3;
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}
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priv->chip.parent = dev;
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priv->chip.owner = THIS_MODULE;
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priv->chip.label = dev_name(dev);
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priv->chip.base = -1;
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priv->chip.ngpio = priv->data->bit_count;
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priv->chip.get = syscon_gpio_get;
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if (priv->data->flags & GPIO_SYSCON_FEAT_IN)
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priv->chip.direction_input = syscon_gpio_dir_in;
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if (priv->data->flags & GPIO_SYSCON_FEAT_OUT) {
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priv->chip.set = priv->data->set ? : syscon_gpio_set;
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priv->chip.direction_output = syscon_gpio_dir_out;
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}
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platform_set_drvdata(pdev, priv);
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return devm_gpiochip_add_data(&pdev->dev, &priv->chip, priv);
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}
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static struct platform_driver syscon_gpio_driver = {
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.driver = {
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.name = "gpio-syscon",
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.of_match_table = syscon_gpio_ids,
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},
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.probe = syscon_gpio_probe,
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};
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module_platform_driver(syscon_gpio_driver);
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MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
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MODULE_DESCRIPTION("SYSCON GPIO driver");
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MODULE_LICENSE("GPL");
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