Commit 6c0b4e6c authored by Alexandre Courbot's avatar Alexandre Courbot Committed by Grant Likely

gpiolib: let gpio_chip reference its descriptors

Add a pointer to the gpio_chip structure that references the array of
GPIO descriptors belonging to the chip, and update gpiolib code to use
this pointer instead of the global gpio_desc[] array. This is another
step towards the removal of the gpio_desc[] global array.
Signed-off-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.orh>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent 372e722e
......@@ -72,6 +72,8 @@ struct gpio_desc {
};
static struct gpio_desc gpio_desc[ARCH_NR_GPIOS];
#define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio)
static LIST_HEAD(gpio_chips);
#ifdef CONFIG_GPIO_SYSFS
......@@ -112,7 +114,7 @@ static inline void desc_set_label(struct gpio_desc *d, const char *label)
*/
static int gpio_chip_hwgpio(const struct gpio_desc *desc)
{
return (desc - &gpio_desc[0]) - desc->chip->base;
return desc - &desc->chip->desc[0];
}
/**
......@@ -133,7 +135,7 @@ static struct gpio_desc *gpio_to_desc(unsigned gpio)
*/
static int desc_to_gpio(const struct gpio_desc *desc)
{
return desc - &gpio_desc[0];
return desc->chip->base + gpio_chip_hwgpio(desc);
}
......@@ -1007,9 +1009,9 @@ static int gpiochip_export(struct gpio_chip *chip)
unsigned gpio;
spin_lock_irqsave(&gpio_lock, flags);
gpio = chip->base;
while (gpio_desc[gpio].chip == chip)
gpio_desc[gpio++].chip = NULL;
gpio = 0;
while (gpio < chip->ngpio)
chip->desc[gpio++].chip = NULL;
spin_unlock_irqrestore(&gpio_lock, flags);
pr_debug("%s: chip %s status %d\n", __func__,
......@@ -1186,8 +1188,11 @@ int gpiochip_add(struct gpio_chip *chip)
status = gpiochip_add_to_list(chip);
if (status == 0) {
for (id = base; id < base + chip->ngpio; id++) {
gpio_desc[id].chip = chip;
chip->desc = &gpio_desc[chip->base];
for (id = 0; id < chip->ngpio; id++) {
struct gpio_desc *desc = &chip->desc[id];
desc->chip = chip;
/* REVISIT: most hardware initializes GPIOs as
* inputs (often with pullups enabled) so power
......@@ -1196,7 +1201,7 @@ int gpiochip_add(struct gpio_chip *chip)
* and in case chip->get_direction is not set,
* we may expose the wrong direction in sysfs.
*/
gpio_desc[id].flags = !chip->direction_input
desc->flags = !chip->direction_input
? (1 << FLAG_IS_OUT)
: 0;
}
......@@ -1249,15 +1254,15 @@ int gpiochip_remove(struct gpio_chip *chip)
gpiochip_remove_pin_ranges(chip);
of_gpiochip_remove(chip);
for (id = chip->base; id < chip->base + chip->ngpio; id++) {
if (test_bit(FLAG_REQUESTED, &gpio_desc[id].flags)) {
for (id = 0; id < chip->ngpio; id++) {
if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) {
status = -EBUSY;
break;
}
}
if (status == 0) {
for (id = chip->base; id < chip->base + chip->ngpio; id++)
gpio_desc[id].chip = NULL;
for (id = 0; id < chip->ngpio; id++)
chip->desc[id].chip = NULL;
list_del(&chip->list);
}
......@@ -1582,11 +1587,13 @@ EXPORT_SYMBOL_GPL(gpio_free_array);
*/
const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
{
unsigned gpio = chip->base + offset;
struct gpio_desc *desc = &gpio_desc[gpio];
struct gpio_desc *desc;
if (!gpio_is_valid(gpio) || desc->chip != chip)
if (!GPIO_OFFSET_VALID(chip, offset))
return NULL;
desc = &chip->desc[offset];
if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
return NULL;
#ifdef CONFIG_DEBUG_FS
......@@ -2025,7 +2032,7 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
unsigned i;
unsigned gpio = chip->base;
struct gpio_desc *gdesc = &gpio_desc[gpio];
struct gpio_desc *gdesc = &chip->desc[0];
int is_out;
for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) {
......
......@@ -47,6 +47,7 @@ struct gpio;
struct seq_file;
struct module;
struct device_node;
struct gpio_desc;
/**
* struct gpio_chip - abstract a GPIO controller
......@@ -76,6 +77,7 @@ struct device_node;
* negative during registration, requests dynamic ID allocation.
* @ngpio: the number of GPIOs handled by this controller; the last GPIO
* handled is (base + ngpio - 1).
* @desc: array of ngpio descriptors. Private.
* @can_sleep: flag must be set iff get()/set() methods sleep, as they
* must while accessing GPIO expander chips over I2C or SPI
* @names: if set, must be an array of strings to use as alternative
......@@ -126,6 +128,7 @@ struct gpio_chip {
struct gpio_chip *chip);
int base;
u16 ngpio;
struct gpio_desc *desc;
const char *const *names;
unsigned can_sleep:1;
unsigned exported:1;
......
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