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linux/drivers/pinctrl/sh-pfc/gpio.c
Geert Uytterhoeven 1d0f9e1e1e pinctrl: sh-pfc: Make legacy function GPIO handling less fragile
If there are no function GPIOs, sh_pfc_register_gpiochip() returns early
with a success indicator.  This is fragile, as new code may be added
after the #ifdef block, which won't be executed in case of early return.

Invert the logic, so the code always continues until the end of the
function on success.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/20191113101809.28600-1-geert+renesas@glider.be
2019-12-09 09:43:02 +01:00

398 lines
9.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* SuperH Pin Function Controller GPIO driver.
*
* Copyright (C) 2008 Magnus Damm
* Copyright (C) 2009 - 2012 Paul Mundt
*/
#include <linux/device.h>
#include <linux/gpio/driver.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/pinctrl/consumer.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include "core.h"
struct sh_pfc_gpio_data_reg {
const struct pinmux_data_reg *info;
u32 shadow;
};
struct sh_pfc_gpio_pin {
u8 dbit;
u8 dreg;
};
struct sh_pfc_chip {
struct sh_pfc *pfc;
struct gpio_chip gpio_chip;
struct sh_pfc_window *mem;
struct sh_pfc_gpio_data_reg *regs;
struct sh_pfc_gpio_pin *pins;
};
static struct sh_pfc *gpio_to_pfc(struct gpio_chip *gc)
{
struct sh_pfc_chip *chip = gpiochip_get_data(gc);
return chip->pfc;
}
static void gpio_get_data_reg(struct sh_pfc_chip *chip, unsigned int offset,
struct sh_pfc_gpio_data_reg **reg,
unsigned int *bit)
{
int idx = sh_pfc_get_pin_index(chip->pfc, offset);
struct sh_pfc_gpio_pin *gpio_pin = &chip->pins[idx];
*reg = &chip->regs[gpio_pin->dreg];
*bit = gpio_pin->dbit;
}
static u32 gpio_read_data_reg(struct sh_pfc_chip *chip,
const struct pinmux_data_reg *dreg)
{
phys_addr_t address = dreg->reg;
void __iomem *mem = address - chip->mem->phys + chip->mem->virt;
return sh_pfc_read_raw_reg(mem, dreg->reg_width);
}
static void gpio_write_data_reg(struct sh_pfc_chip *chip,
const struct pinmux_data_reg *dreg, u32 value)
{
phys_addr_t address = dreg->reg;
void __iomem *mem = address - chip->mem->phys + chip->mem->virt;
sh_pfc_write_raw_reg(mem, dreg->reg_width, value);
}
static void gpio_setup_data_reg(struct sh_pfc_chip *chip, unsigned idx)
{
struct sh_pfc *pfc = chip->pfc;
struct sh_pfc_gpio_pin *gpio_pin = &chip->pins[idx];
const struct sh_pfc_pin *pin = &pfc->info->pins[idx];
const struct pinmux_data_reg *dreg;
unsigned int bit;
unsigned int i;
for (i = 0, dreg = pfc->info->data_regs; dreg->reg_width; ++i, ++dreg) {
for (bit = 0; bit < dreg->reg_width; bit++) {
if (dreg->enum_ids[bit] == pin->enum_id) {
gpio_pin->dreg = i;
gpio_pin->dbit = bit;
return;
}
}
}
BUG();
}
static int gpio_setup_data_regs(struct sh_pfc_chip *chip)
{
struct sh_pfc *pfc = chip->pfc;
const struct pinmux_data_reg *dreg;
unsigned int i;
/* Count the number of data registers, allocate memory and initialize
* them.
*/
for (i = 0; pfc->info->data_regs[i].reg_width; ++i)
;
chip->regs = devm_kcalloc(pfc->dev, i, sizeof(*chip->regs),
GFP_KERNEL);
if (chip->regs == NULL)
return -ENOMEM;
for (i = 0, dreg = pfc->info->data_regs; dreg->reg_width; ++i, ++dreg) {
chip->regs[i].info = dreg;
chip->regs[i].shadow = gpio_read_data_reg(chip, dreg);
}
for (i = 0; i < pfc->info->nr_pins; i++) {
if (pfc->info->pins[i].enum_id == 0)
continue;
gpio_setup_data_reg(chip, i);
}
return 0;
}
/* -----------------------------------------------------------------------------
* Pin GPIOs
*/
static int gpio_pin_request(struct gpio_chip *gc, unsigned offset)
{
struct sh_pfc *pfc = gpio_to_pfc(gc);
int idx = sh_pfc_get_pin_index(pfc, offset);
if (idx < 0 || pfc->info->pins[idx].enum_id == 0)
return -EINVAL;
return pinctrl_gpio_request(offset);
}
static void gpio_pin_free(struct gpio_chip *gc, unsigned offset)
{
return pinctrl_gpio_free(offset);
}
static void gpio_pin_set_value(struct sh_pfc_chip *chip, unsigned offset,
int value)
{
struct sh_pfc_gpio_data_reg *reg;
unsigned int bit;
unsigned int pos;
gpio_get_data_reg(chip, offset, &reg, &bit);
pos = reg->info->reg_width - (bit + 1);
if (value)
reg->shadow |= BIT(pos);
else
reg->shadow &= ~BIT(pos);
gpio_write_data_reg(chip, reg->info, reg->shadow);
}
static int gpio_pin_direction_input(struct gpio_chip *gc, unsigned offset)
{
return pinctrl_gpio_direction_input(offset);
}
static int gpio_pin_direction_output(struct gpio_chip *gc, unsigned offset,
int value)
{
gpio_pin_set_value(gpiochip_get_data(gc), offset, value);
return pinctrl_gpio_direction_output(offset);
}
static int gpio_pin_get(struct gpio_chip *gc, unsigned offset)
{
struct sh_pfc_chip *chip = gpiochip_get_data(gc);
struct sh_pfc_gpio_data_reg *reg;
unsigned int bit;
unsigned int pos;
gpio_get_data_reg(chip, offset, &reg, &bit);
pos = reg->info->reg_width - (bit + 1);
return (gpio_read_data_reg(chip, reg->info) >> pos) & 1;
}
static void gpio_pin_set(struct gpio_chip *gc, unsigned offset, int value)
{
gpio_pin_set_value(gpiochip_get_data(gc), offset, value);
}
static int gpio_pin_to_irq(struct gpio_chip *gc, unsigned offset)
{
struct sh_pfc *pfc = gpio_to_pfc(gc);
unsigned int i, k;
for (i = 0; i < pfc->info->gpio_irq_size; i++) {
const short *gpios = pfc->info->gpio_irq[i].gpios;
for (k = 0; gpios[k] >= 0; k++) {
if (gpios[k] == offset)
goto found;
}
}
return 0;
found:
return pfc->irqs[i];
}
static int gpio_pin_setup(struct sh_pfc_chip *chip)
{
struct sh_pfc *pfc = chip->pfc;
struct gpio_chip *gc = &chip->gpio_chip;
int ret;
chip->pins = devm_kcalloc(pfc->dev,
pfc->info->nr_pins, sizeof(*chip->pins),
GFP_KERNEL);
if (chip->pins == NULL)
return -ENOMEM;
ret = gpio_setup_data_regs(chip);
if (ret < 0)
return ret;
gc->request = gpio_pin_request;
gc->free = gpio_pin_free;
gc->direction_input = gpio_pin_direction_input;
gc->get = gpio_pin_get;
gc->direction_output = gpio_pin_direction_output;
gc->set = gpio_pin_set;
gc->to_irq = gpio_pin_to_irq;
gc->label = pfc->info->name;
gc->parent = pfc->dev;
gc->owner = THIS_MODULE;
gc->base = 0;
gc->ngpio = pfc->nr_gpio_pins;
return 0;
}
/* -----------------------------------------------------------------------------
* Function GPIOs
*/
#ifdef CONFIG_PINCTRL_SH_FUNC_GPIO
static int gpio_function_request(struct gpio_chip *gc, unsigned offset)
{
struct sh_pfc *pfc = gpio_to_pfc(gc);
unsigned int mark = pfc->info->func_gpios[offset].enum_id;
unsigned long flags;
int ret;
dev_notice_once(pfc->dev,
"Use of GPIO API for function requests is deprecated, convert to pinctrl\n");
if (mark == 0)
return -EINVAL;
spin_lock_irqsave(&pfc->lock, flags);
ret = sh_pfc_config_mux(pfc, mark, PINMUX_TYPE_FUNCTION);
spin_unlock_irqrestore(&pfc->lock, flags);
return ret;
}
static int gpio_function_setup(struct sh_pfc_chip *chip)
{
struct sh_pfc *pfc = chip->pfc;
struct gpio_chip *gc = &chip->gpio_chip;
gc->request = gpio_function_request;
gc->label = pfc->info->name;
gc->owner = THIS_MODULE;
gc->base = pfc->nr_gpio_pins;
gc->ngpio = pfc->info->nr_func_gpios;
return 0;
}
#endif /* CONFIG_PINCTRL_SH_FUNC_GPIO */
/* -----------------------------------------------------------------------------
* Register/unregister
*/
static struct sh_pfc_chip *
sh_pfc_add_gpiochip(struct sh_pfc *pfc, int(*setup)(struct sh_pfc_chip *),
struct sh_pfc_window *mem)
{
struct sh_pfc_chip *chip;
int ret;
chip = devm_kzalloc(pfc->dev, sizeof(*chip), GFP_KERNEL);
if (unlikely(!chip))
return ERR_PTR(-ENOMEM);
chip->mem = mem;
chip->pfc = pfc;
ret = setup(chip);
if (ret < 0)
return ERR_PTR(ret);
ret = devm_gpiochip_add_data(pfc->dev, &chip->gpio_chip, chip);
if (unlikely(ret < 0))
return ERR_PTR(ret);
dev_info(pfc->dev, "%s handling gpio %u -> %u\n",
chip->gpio_chip.label, chip->gpio_chip.base,
chip->gpio_chip.base + chip->gpio_chip.ngpio - 1);
return chip;
}
int sh_pfc_register_gpiochip(struct sh_pfc *pfc)
{
struct sh_pfc_chip *chip;
phys_addr_t address;
unsigned int i;
if (pfc->info->data_regs == NULL)
return 0;
/* Find the memory window that contain the GPIO registers. Boards that
* register a separate GPIO device will not supply a memory resource
* that covers the data registers. In that case don't try to handle
* GPIOs.
*/
address = pfc->info->data_regs[0].reg;
for (i = 0; i < pfc->num_windows; ++i) {
struct sh_pfc_window *window = &pfc->windows[i];
if (address >= window->phys &&
address < window->phys + window->size)
break;
}
if (i == pfc->num_windows)
return 0;
/* If we have IRQ resources make sure their number is correct. */
if (pfc->num_irqs != pfc->info->gpio_irq_size) {
dev_err(pfc->dev, "invalid number of IRQ resources\n");
return -EINVAL;
}
/* Register the real GPIOs chip. */
chip = sh_pfc_add_gpiochip(pfc, gpio_pin_setup, &pfc->windows[i]);
if (IS_ERR(chip))
return PTR_ERR(chip);
pfc->gpio = chip;
if (IS_ENABLED(CONFIG_OF) && pfc->dev->of_node)
return 0;
#ifdef CONFIG_PINCTRL_SH_FUNC_GPIO
/*
* Register the GPIO to pin mappings. As pins with GPIO ports
* must come first in the ranges, skip the pins without GPIO
* ports by stopping at the first range that contains such a
* pin.
*/
for (i = 0; i < pfc->nr_ranges; ++i) {
const struct sh_pfc_pin_range *range = &pfc->ranges[i];
int ret;
if (range->start >= pfc->nr_gpio_pins)
break;
ret = gpiochip_add_pin_range(&chip->gpio_chip,
dev_name(pfc->dev), range->start, range->start,
range->end - range->start + 1);
if (ret < 0)
return ret;
}
/* Register the function GPIOs chip. */
if (pfc->info->nr_func_gpios) {
chip = sh_pfc_add_gpiochip(pfc, gpio_function_setup, NULL);
if (IS_ERR(chip))
return PTR_ERR(chip);
}
#endif /* CONFIG_PINCTRL_SH_FUNC_GPIO */
return 0;
}