summaryrefslogtreecommitdiff
path: root/drivers/gpio/gpiolib.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/gpio/gpiolib.c')
-rw-r--r--drivers/gpio/gpiolib.c143
1 files changed, 126 insertions, 17 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 5dfd3c17fffc..e11a3bb03820 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -61,6 +61,11 @@ static struct bus_type gpio_bus_type = {
.name = "gpio",
};
+/*
+ * Number of GPIOs to use for the fast path in set array
+ */
+#define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
+
/* gpio_lock prevents conflicts during gpio_desc[] table updates.
* While any GPIO is requested, its gpio_chip is not removable;
* each GPIO's "requested" flag serves as a lock and refcount.
@@ -71,6 +76,9 @@ static DEFINE_MUTEX(gpio_lookup_lock);
static LIST_HEAD(gpio_lookup_list);
LIST_HEAD(gpio_devices);
+static DEFINE_MUTEX(gpio_machine_hogs_mutex);
+static LIST_HEAD(gpio_machine_hogs);
+
static void gpiochip_free_hogs(struct gpio_chip *chip);
static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
struct lock_class_key *lock_key,
@@ -450,12 +458,11 @@ static long linehandle_ioctl(struct file *filep, unsigned int cmd,
vals[i] = !!ghd.values[i];
/* Reuse the array setting function */
- gpiod_set_array_value_complex(false,
+ return gpiod_set_array_value_complex(false,
true,
lh->numdescs,
lh->descs,
vals);
- return 0;
}
return -EINVAL;
}
@@ -1172,6 +1179,41 @@ err_remove_device:
return status;
}
+static void gpiochip_machine_hog(struct gpio_chip *chip, struct gpiod_hog *hog)
+{
+ struct gpio_desc *desc;
+ int rv;
+
+ desc = gpiochip_get_desc(chip, hog->chip_hwnum);
+ if (IS_ERR(desc)) {
+ pr_err("%s: unable to get GPIO desc: %ld\n",
+ __func__, PTR_ERR(desc));
+ return;
+ }
+
+ if (test_bit(FLAG_IS_HOGGED, &desc->flags))
+ return;
+
+ rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
+ if (rv)
+ pr_err("%s: unable to hog GPIO line (%s:%u): %d\n",
+ __func__, chip->label, hog->chip_hwnum, rv);
+}
+
+static void machine_gpiochip_add(struct gpio_chip *chip)
+{
+ struct gpiod_hog *hog;
+
+ mutex_lock(&gpio_machine_hogs_mutex);
+
+ list_for_each_entry(hog, &gpio_machine_hogs, list) {
+ if (!strcmp(chip->label, hog->chip_label))
+ gpiochip_machine_hog(chip, hog);
+ }
+
+ mutex_unlock(&gpio_machine_hogs_mutex);
+}
+
static void gpiochip_setup_devs(void)
{
struct gpio_device *gdev;
@@ -1244,6 +1286,10 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
goto err_free_descs;
}
+ if (chip->ngpio > FASTPATH_NGPIO)
+ chip_warn(chip, "line cnt %u is greater than fast path cnt %u\n",
+ chip->ngpio, FASTPATH_NGPIO);
+
gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
if (!gdev->label) {
status = -ENOMEM;
@@ -1327,6 +1373,8 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
acpi_gpiochip_add(chip);
+ machine_gpiochip_add(chip);
+
/*
* By first adding the chardev, and then adding the device,
* we get a device node entry in sysfs under
@@ -2729,16 +2777,28 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep,
while (i < array_size) {
struct gpio_chip *chip = desc_array[i]->gdev->chip;
- unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
- unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
+ unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
+ unsigned long *mask, *bits;
int first, j, ret;
+ if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
+ mask = fastpath;
+ } else {
+ mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
+ sizeof(*mask),
+ can_sleep ? GFP_KERNEL : GFP_ATOMIC);
+ if (!mask)
+ return -ENOMEM;
+ }
+
+ bits = mask + BITS_TO_LONGS(chip->ngpio);
+ bitmap_zero(mask, chip->ngpio);
+
if (!can_sleep)
WARN_ON(chip->can_sleep);
/* collect all inputs belonging to the same chip */
first = i;
- memset(mask, 0, sizeof(mask));
do {
const struct gpio_desc *desc = desc_array[i];
int hwgpio = gpio_chip_hwgpio(desc);
@@ -2749,8 +2809,11 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep,
(desc_array[i]->gdev->chip == chip));
ret = gpio_chip_get_multiple(chip, mask, bits);
- if (ret)
+ if (ret) {
+ if (mask != fastpath)
+ kfree(mask);
return ret;
+ }
for (j = first; j < i; j++) {
const struct gpio_desc *desc = desc_array[j];
@@ -2762,6 +2825,9 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep,
value_array[j] = value;
trace_gpio_value(desc_to_gpio(desc), 1, value);
}
+
+ if (mask != fastpath)
+ kfree(mask);
}
return 0;
}
@@ -2945,7 +3011,7 @@ static void gpio_chip_set_multiple(struct gpio_chip *chip,
}
}
-void gpiod_set_array_value_complex(bool raw, bool can_sleep,
+int gpiod_set_array_value_complex(bool raw, bool can_sleep,
unsigned int array_size,
struct gpio_desc **desc_array,
int *value_array)
@@ -2954,14 +3020,26 @@ void gpiod_set_array_value_complex(bool raw, bool can_sleep,
while (i < array_size) {
struct gpio_chip *chip = desc_array[i]->gdev->chip;
- unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
- unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
+ unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
+ unsigned long *mask, *bits;
int count = 0;
+ if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
+ mask = fastpath;
+ } else {
+ mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
+ sizeof(*mask),
+ can_sleep ? GFP_KERNEL : GFP_ATOMIC);
+ if (!mask)
+ return -ENOMEM;
+ }
+
+ bits = mask + BITS_TO_LONGS(chip->ngpio);
+ bitmap_zero(mask, chip->ngpio);
+
if (!can_sleep)
WARN_ON(chip->can_sleep);
- memset(mask, 0, sizeof(mask));
do {
struct gpio_desc *desc = desc_array[i];
int hwgpio = gpio_chip_hwgpio(desc);
@@ -2992,7 +3070,11 @@ void gpiod_set_array_value_complex(bool raw, bool can_sleep,
/* push collected bits to outputs */
if (count != 0)
gpio_chip_set_multiple(chip, mask, bits);
+
+ if (mask != fastpath)
+ kfree(mask);
}
+ return 0;
}
/**
@@ -3067,13 +3149,13 @@ EXPORT_SYMBOL_GPL(gpiod_set_value);
* This function should be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
-void gpiod_set_raw_array_value(unsigned int array_size,
+int gpiod_set_raw_array_value(unsigned int array_size,
struct gpio_desc **desc_array, int *value_array)
{
if (!desc_array)
- return;
- gpiod_set_array_value_complex(true, false, array_size, desc_array,
- value_array);
+ return -EINVAL;
+ return gpiod_set_array_value_complex(true, false, array_size,
+ desc_array, value_array);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
@@ -3393,14 +3475,14 @@ EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
*
* This function is to be called from contexts that can sleep.
*/
-void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
+int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
int *value_array)
{
might_sleep_if(extra_checks);
if (!desc_array)
- return;
- gpiod_set_array_value_complex(true, true, array_size, desc_array,
+ return -EINVAL;
+ return gpiod_set_array_value_complex(true, true, array_size, desc_array,
value_array);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
@@ -3473,6 +3555,33 @@ void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
}
EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
+/**
+ * gpiod_add_hogs() - register a set of GPIO hogs from machine code
+ * @hogs: table of gpio hog entries with a zeroed sentinel at the end
+ */
+void gpiod_add_hogs(struct gpiod_hog *hogs)
+{
+ struct gpio_chip *chip;
+ struct gpiod_hog *hog;
+
+ mutex_lock(&gpio_machine_hogs_mutex);
+
+ for (hog = &hogs[0]; hog->chip_label; hog++) {
+ list_add_tail(&hog->list, &gpio_machine_hogs);
+
+ /*
+ * The chip may have been registered earlier, so check if it
+ * exists and, if so, try to hog the line now.
+ */
+ chip = find_chip_by_name(hog->chip_label);
+ if (chip)
+ gpiochip_machine_hog(chip, hog);
+ }
+
+ mutex_unlock(&gpio_machine_hogs_mutex);
+}
+EXPORT_SYMBOL_GPL(gpiod_add_hogs);
+
static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
{
const char *dev_id = dev ? dev_name(dev) : NULL;
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-26 23:37:11 +0300