linux/drivers/pinctrl/sh-pfc/gpio.c
Laurent Pinchart ceef91dcc0 sh-pfc: Skip gpiochip registration when no GPIO resource is found
Boards/platforms that register dedicated GPIO devices will not supply a
memory resource for GPIOs. Try to locate the GPIO memory resource at
initialization time, and skip registration of the gpiochip if the
resource can't be found.

This is a temporary modification to ease the transition to separate GPIO
drivers. It should be reverted when all boards and platforms will have
been moved.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-04-03 10:30:36 +09:00

415 lines
9.4 KiB
C

/*
* SuperH Pin Function Controller GPIO driver.
*
* Copyright (C) 2008 Magnus Damm
* Copyright (C) 2009 - 2012 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/device.h>
#include <linux/gpio.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;
unsigned long 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_chip *gpio_to_pfc_chip(struct gpio_chip *gc)
{
return container_of(gc, struct sh_pfc_chip, gpio_chip);
}
static struct sh_pfc *gpio_to_pfc(struct gpio_chip *gc)
{
return gpio_to_pfc_chip(gc)->pfc;
}
static void gpio_get_data_reg(struct sh_pfc_chip *chip, unsigned int gpio,
struct sh_pfc_gpio_data_reg **reg,
unsigned int *bit)
{
int idx = sh_pfc_get_pin_index(chip->pfc, gpio);
struct sh_pfc_gpio_pin *gpio_pin = &chip->pins[idx];
*reg = &chip->regs[gpio_pin->dreg];
*bit = gpio_pin->dbit;
}
static unsigned long gpio_read_data_reg(struct sh_pfc_chip *chip,
const struct pinmux_data_reg *dreg)
{
void __iomem *mem = dreg->reg - 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,
unsigned long value)
{
void __iomem *mem = dreg->reg - 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 gpio)
{
struct sh_pfc *pfc = chip->pfc;
struct sh_pfc_gpio_pin *gpio_pin = &chip->pins[gpio];
const struct sh_pfc_pin *pin = &pfc->info->pins[gpio];
const struct pinmux_data_reg *dreg;
unsigned int bit;
unsigned int i;
for (i = 0, dreg = pfc->info->data_regs; dreg->reg; ++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_kzalloc(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_request_gpio(offset);
}
static void gpio_pin_free(struct gpio_chip *gc, unsigned offset)
{
return pinctrl_free_gpio(offset);
}
static void gpio_pin_set_value(struct sh_pfc_chip *chip, unsigned offset,
int value)
{
struct sh_pfc_gpio_data_reg *reg;
unsigned long pos;
unsigned int bit;
gpio_get_data_reg(chip, offset, &reg, &bit);
pos = reg->info->reg_width - (bit + 1);
if (value)
set_bit(pos, &reg->shadow);
else
clear_bit(pos, &reg->shadow);
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(gpio_to_pfc_chip(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 = gpio_to_pfc_chip(gc);
struct sh_pfc_gpio_data_reg *reg;
unsigned long pos;
unsigned int bit;
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(gpio_to_pfc_chip(gc), offset, value);
}
static int gpio_pin_to_irq(struct gpio_chip *gc, unsigned offset)
{
struct sh_pfc *pfc = gpio_to_pfc(gc);
int i, k;
for (i = 0; i < pfc->info->gpio_irq_size; i++) {
unsigned short *gpios = pfc->info->gpio_irq[i].gpios;
for (k = 0; gpios[k]; k++) {
if (gpios[k] == offset)
return pfc->info->gpio_irq[i].irq;
}
}
return -ENOSYS;
}
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_kzalloc(pfc->dev, pfc->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->dev = pfc->dev;
gc->owner = THIS_MODULE;
gc->base = 0;
gc->ngpio = pfc->nr_pins;
return 0;
}
/* -----------------------------------------------------------------------------
* Function GPIOs
*/
static int gpio_function_request(struct gpio_chip *gc, unsigned offset)
{
static bool __print_once;
struct sh_pfc *pfc = gpio_to_pfc(gc);
unsigned int mark = pfc->info->func_gpios[offset].enum_id;
unsigned long flags;
int ret;
if (!__print_once) {
dev_notice(pfc->dev,
"Use of GPIO API for function requests is deprecated."
" Convert to pinctrl\n");
__print_once = true;
}
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 void gpio_function_free(struct gpio_chip *gc, unsigned offset)
{
}
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->free = gpio_function_free;
gc->label = pfc->info->name;
gc->owner = THIS_MODULE;
gc->base = pfc->nr_pins;
gc->ngpio = pfc->info->nr_func_gpios;
return 0;
}
/* -----------------------------------------------------------------------------
* 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 = gpiochip_add(&chip->gpio_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)
{
const struct pinmux_range *ranges;
struct pinmux_range def_range;
struct sh_pfc_chip *chip;
unsigned int nr_ranges;
unsigned int i;
int ret;
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.
*/
for (i = 0; i < pfc->num_windows; ++i) {
struct sh_pfc_window *window = &pfc->window[i];
if (pfc->info->data_regs[0].reg >= window->phys &&
pfc->info->data_regs[0].reg < window->phys + window->size)
break;
}
if (i == pfc->num_windows)
return 0;
/* Register the real GPIOs chip. */
chip = sh_pfc_add_gpiochip(pfc, gpio_pin_setup, &pfc->window[i]);
if (IS_ERR(chip))
return PTR_ERR(chip);
pfc->gpio = chip;
/* Register the GPIO to pin mappings. */
if (pfc->info->ranges == NULL) {
def_range.begin = 0;
def_range.end = pfc->info->nr_pins - 1;
ranges = &def_range;
nr_ranges = 1;
} else {
ranges = pfc->info->ranges;
nr_ranges = pfc->info->nr_ranges;
}
for (i = 0; i < nr_ranges; ++i) {
const struct pinmux_range *range = &ranges[i];
ret = gpiochip_add_pin_range(&chip->gpio_chip,
dev_name(pfc->dev),
range->begin, range->begin,
range->end - range->begin + 1);
if (ret < 0)
return ret;
}
/* Register the function GPIOs chip. */
if (pfc->info->nr_func_gpios == 0)
return 0;
chip = sh_pfc_add_gpiochip(pfc, gpio_function_setup, NULL);
if (IS_ERR(chip))
return PTR_ERR(chip);
pfc->func = chip;
return 0;
}
int sh_pfc_unregister_gpiochip(struct sh_pfc *pfc)
{
int err;
int ret;
ret = gpiochip_remove(&pfc->gpio->gpio_chip);
err = gpiochip_remove(&pfc->func->gpio_chip);
return ret < 0 ? ret : err;
}