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-rw-r--r--drivers/gpio/gpiolib.c129
-rw-r--r--drivers/gpio/mcp23s08.c3
-rw-r--r--drivers/gpio/pca953x.c30
-rw-r--r--drivers/gpio/pcf857x.c37
4 files changed, 145 insertions, 54 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index d8db2f8ee41..beaf6b3a37d 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -43,6 +43,7 @@ struct gpio_desc {
/* flag symbols are bit numbers */
#define FLAG_REQUESTED 0
#define FLAG_IS_OUT 1
+#define FLAG_RESERVED 2
#ifdef CONFIG_DEBUG_FS
const char *label;
@@ -68,6 +69,9 @@ static void gpio_ensure_requested(struct gpio_desc *desc)
if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
pr_warning("GPIO-%d autorequested\n", (int)(desc - gpio_desc));
desc_set_label(desc, "[auto]");
+ if (!try_module_get(desc->chip->owner))
+ pr_err("GPIO-%d: module can't be gotten \n",
+ (int)(desc - gpio_desc));
}
}
@@ -77,6 +81,76 @@ static inline struct gpio_chip *gpio_to_chip(unsigned gpio)
return gpio_desc[gpio].chip;
}
+/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
+static int gpiochip_find_base(int ngpio)
+{
+ int i;
+ int spare = 0;
+ int base = -ENOSPC;
+
+ for (i = ARCH_NR_GPIOS - 1; i >= 0 ; i--) {
+ struct gpio_desc *desc = &gpio_desc[i];
+ struct gpio_chip *chip = desc->chip;
+
+ if (!chip && !test_bit(FLAG_RESERVED, &desc->flags)) {
+ spare++;
+ if (spare == ngpio) {
+ base = i;
+ break;
+ }
+ } else {
+ spare = 0;
+ if (chip)
+ i -= chip->ngpio - 1;
+ }
+ }
+
+ if (gpio_is_valid(base))
+ pr_debug("%s: found new base at %d\n", __func__, base);
+ return base;
+}
+
+/**
+ * gpiochip_reserve() - reserve range of gpios to use with platform code only
+ * @start: starting gpio number
+ * @ngpio: number of gpios to reserve
+ * Context: platform init, potentially before irqs or kmalloc will work
+ *
+ * Returns a negative errno if any gpio within the range is already reserved
+ * or registered, else returns zero as a success code. Use this function
+ * to mark a range of gpios as unavailable for dynamic gpio number allocation,
+ * for example because its driver support is not yet loaded.
+ */
+int __init gpiochip_reserve(int start, int ngpio)
+{
+ int ret = 0;
+ unsigned long flags;
+ int i;
+
+ if (!gpio_is_valid(start) || !gpio_is_valid(start + ngpio - 1))
+ return -EINVAL;
+
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ for (i = start; i < start + ngpio; i++) {
+ struct gpio_desc *desc = &gpio_desc[i];
+
+ if (desc->chip || test_bit(FLAG_RESERVED, &desc->flags)) {
+ ret = -EBUSY;
+ goto err;
+ }
+
+ set_bit(FLAG_RESERVED, &desc->flags);
+ }
+
+ pr_debug("%s: reserved gpios from %d to %d\n",
+ __func__, start, start + ngpio - 1);
+err:
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
+ return ret;
+}
+
/**
* gpiochip_add() - register a gpio_chip
* @chip: the chip to register, with chip->base initialized
@@ -85,44 +159,55 @@ static inline struct gpio_chip *gpio_to_chip(unsigned gpio)
* Returns a negative errno if the chip can't be registered, such as
* because the chip->base is invalid or already associated with a
* different chip. Otherwise it returns zero as a success code.
+ *
+ * If chip->base is negative, this requests dynamic assignment of
+ * a range of valid GPIOs.
*/
int gpiochip_add(struct gpio_chip *chip)
{
unsigned long flags;
int status = 0;
unsigned id;
+ int base = chip->base;
- /* NOTE chip->base negative is reserved to mean a request for
- * dynamic allocation. We don't currently support that.
- */
-
- if (chip->base < 0 || (chip->base + chip->ngpio) >= ARCH_NR_GPIOS) {
+ if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1))
+ && base >= 0) {
status = -EINVAL;
goto fail;
}
spin_lock_irqsave(&gpio_lock, flags);
+ if (base < 0) {
+ base = gpiochip_find_base(chip->ngpio);
+ if (base < 0) {
+ status = base;
+ goto fail_unlock;
+ }
+ chip->base = base;
+ }
+
/* these GPIO numbers must not be managed by another gpio_chip */
- for (id = chip->base; id < chip->base + chip->ngpio; id++) {
+ for (id = base; id < base + chip->ngpio; id++) {
if (gpio_desc[id].chip != NULL) {
status = -EBUSY;
break;
}
}
if (status == 0) {
- for (id = chip->base; id < chip->base + chip->ngpio; id++) {
+ for (id = base; id < base + chip->ngpio; id++) {
gpio_desc[id].chip = chip;
gpio_desc[id].flags = 0;
}
}
+fail_unlock:
spin_unlock_irqrestore(&gpio_lock, flags);
fail:
/* failures here can mean systems won't boot... */
if (status)
pr_err("gpiochip_add: gpios %d..%d (%s) not registered\n",
- chip->base, chip->base + chip->ngpio,
+ chip->base, chip->base + chip->ngpio - 1,
chip->label ? : "generic");
return status;
}
@@ -171,12 +256,15 @@ int gpio_request(unsigned gpio, const char *label)
spin_lock_irqsave(&gpio_lock, flags);
- if (gpio >= ARCH_NR_GPIOS)
+ if (!gpio_is_valid(gpio))
goto done;
desc = &gpio_desc[gpio];
if (desc->chip == NULL)
goto done;
+ if (!try_module_get(desc->chip->owner))
+ goto done;
+
/* NOTE: gpio_request() can be called in early boot,
* before IRQs are enabled.
*/
@@ -184,8 +272,10 @@ int gpio_request(unsigned gpio, const char *label)
if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
desc_set_label(desc, label ? : "?");
status = 0;
- } else
+ } else {
status = -EBUSY;
+ module_put(desc->chip->owner);
+ }
done:
if (status)
@@ -201,7 +291,7 @@ void gpio_free(unsigned gpio)
unsigned long flags;
struct gpio_desc *desc;
- if (gpio >= ARCH_NR_GPIOS) {
+ if (!gpio_is_valid(gpio)) {
WARN_ON(extra_checks);
return;
}
@@ -209,9 +299,10 @@ void gpio_free(unsigned gpio)
spin_lock_irqsave(&gpio_lock, flags);
desc = &gpio_desc[gpio];
- if (desc->chip && test_and_clear_bit(FLAG_REQUESTED, &desc->flags))
+ if (desc->chip && test_and_clear_bit(FLAG_REQUESTED, &desc->flags)) {
desc_set_label(desc, NULL);
- else
+ module_put(desc->chip->owner);
+ } else
WARN_ON(extra_checks);
spin_unlock_irqrestore(&gpio_lock, flags);
@@ -236,7 +327,7 @@ const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
{
unsigned gpio = chip->base + offset;
- if (gpio >= ARCH_NR_GPIOS || gpio_desc[gpio].chip != chip)
+ if (!gpio_is_valid(gpio) || gpio_desc[gpio].chip != chip)
return NULL;
if (test_bit(FLAG_REQUESTED, &gpio_desc[gpio].flags) == 0)
return NULL;
@@ -267,7 +358,7 @@ int gpio_direction_input(unsigned gpio)
spin_lock_irqsave(&gpio_lock, flags);
- if (gpio >= ARCH_NR_GPIOS)
+ if (!gpio_is_valid(gpio))
goto fail;
chip = desc->chip;
if (!chip || !chip->get || !chip->direction_input)
@@ -291,7 +382,7 @@ fail:
spin_unlock_irqrestore(&gpio_lock, flags);
if (status)
pr_debug("%s: gpio-%d status %d\n",
- __FUNCTION__, gpio, status);
+ __func__, gpio, status);
return status;
}
EXPORT_SYMBOL_GPL(gpio_direction_input);
@@ -305,7 +396,7 @@ int gpio_direction_output(unsigned gpio, int value)
spin_lock_irqsave(&gpio_lock, flags);
- if (gpio >= ARCH_NR_GPIOS)
+ if (!gpio_is_valid(gpio))
goto fail;
chip = desc->chip;
if (!chip || !chip->set || !chip->direction_output)
@@ -329,7 +420,7 @@ fail:
spin_unlock_irqrestore(&gpio_lock, flags);
if (status)
pr_debug("%s: gpio-%d status %d\n",
- __FUNCTION__, gpio, status);
+ __func__, gpio, status);
return status;
}
EXPORT_SYMBOL_GPL(gpio_direction_output);
@@ -522,7 +613,7 @@ static int gpiolib_show(struct seq_file *s, void *unused)
/* REVISIT this isn't locked against gpio_chip removal ... */
- for (gpio = 0; gpio < ARCH_NR_GPIOS; gpio++) {
+ for (gpio = 0; gpio_is_valid(gpio); gpio++) {
if (chip == gpio_desc[gpio].chip)
continue;
chip = gpio_desc[gpio].chip;
diff --git a/drivers/gpio/mcp23s08.c b/drivers/gpio/mcp23s08.c
index bb60e8c1a1f..7f92fdd5f0e 100644
--- a/drivers/gpio/mcp23s08.c
+++ b/drivers/gpio/mcp23s08.c
@@ -168,7 +168,7 @@ static void mcp23s08_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
struct mcp23s08 *mcp;
char bank;
- unsigned t;
+ int t;
unsigned mask;
mcp = container_of(chip, struct mcp23s08, chip);
@@ -239,6 +239,7 @@ static int mcp23s08_probe(struct spi_device *spi)
mcp->chip.base = pdata->base;
mcp->chip.ngpio = 8;
mcp->chip.can_sleep = 1;
+ mcp->chip.owner = THIS_MODULE;
spi_set_drvdata(spi, mcp);
diff --git a/drivers/gpio/pca953x.c b/drivers/gpio/pca953x.c
index 6e72fd31184..7e40e8a55ed 100644
--- a/drivers/gpio/pca953x.c
+++ b/drivers/gpio/pca953x.c
@@ -23,21 +23,20 @@
#define PCA953X_INVERT 2
#define PCA953X_DIRECTION 3
-/* This is temporary - in 2.6.26 i2c_driver_data should replace it. */
-struct pca953x_desc {
- char name[I2C_NAME_SIZE];
- unsigned long driver_data;
-};
-
-static const struct pca953x_desc pca953x_descs[] = {
+static const struct i2c_device_id pca953x_id[] = {
{ "pca9534", 8, },
{ "pca9535", 16, },
{ "pca9536", 4, },
{ "pca9537", 4, },
{ "pca9538", 8, },
{ "pca9539", 16, },
+ { "pca9554", 8, },
+ { "pca9555", 16, },
+ { "pca9557", 8, },
/* REVISIT several pca955x parts should work here too */
+ { }
};
+MODULE_DEVICE_TABLE(i2c, pca953x_id);
struct pca953x_chip {
unsigned gpio_start;
@@ -189,28 +188,20 @@ static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
gc->base = chip->gpio_start;
gc->ngpio = gpios;
gc->label = chip->client->name;
+ gc->owner = THIS_MODULE;
}
-static int __devinit pca953x_probe(struct i2c_client *client)
+static int __devinit pca953x_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
{
struct pca953x_platform_data *pdata;
struct pca953x_chip *chip;
- int ret, i;
- const struct pca953x_desc *id = NULL;
+ int ret;
pdata = client->dev.platform_data;
if (pdata == NULL)
return -ENODEV;
- /* this loop vanishes when we get i2c_device_id */
- for (i = 0; i < ARRAY_SIZE(pca953x_descs); i++)
- if (!strcmp(pca953x_descs[i].name, client->name)) {
- id = pca953x_descs + i;
- break;
- }
- if (!id)
- return -ENODEV;
-
chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL);
if (chip == NULL)
return -ENOMEM;
@@ -290,6 +281,7 @@ static struct i2c_driver pca953x_driver = {
},
.probe = pca953x_probe,
.remove = pca953x_remove,
+ .id_table = pca953x_id,
};
static int __init pca953x_init(void)
diff --git a/drivers/gpio/pcf857x.c b/drivers/gpio/pcf857x.c
index c6b3b537838..aa6cc8b2a2b 100644
--- a/drivers/gpio/pcf857x.c
+++ b/drivers/gpio/pcf857x.c
@@ -26,6 +26,21 @@
#include <asm/gpio.h>
+static const struct i2c_device_id pcf857x_id[] = {
+ { "pcf8574", 8 },
+ { "pca8574", 8 },
+ { "pca9670", 8 },
+ { "pca9672", 8 },
+ { "pca9674", 8 },
+ { "pcf8575", 16 },
+ { "pca8575", 16 },
+ { "pca9671", 16 },
+ { "pca9673", 16 },
+ { "pca9675", 16 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, pcf857x_id);
+
/*
* The pcf857x, pca857x, and pca967x chips only expose one read and one
* write register. Writing a "one" bit (to match the reset state) lets
@@ -142,7 +157,8 @@ static void pcf857x_set16(struct gpio_chip *chip, unsigned offset, int value)
/*-------------------------------------------------------------------------*/
-static int pcf857x_probe(struct i2c_client *client)
+static int pcf857x_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
{
struct pcf857x_platform_data *pdata;
struct pcf857x *gpio;
@@ -159,6 +175,7 @@ static int pcf857x_probe(struct i2c_client *client)
gpio->chip.base = pdata->gpio_base;
gpio->chip.can_sleep = 1;
+ gpio->chip.owner = THIS_MODULE;
/* NOTE: the OnSemi jlc1562b is also largely compatible with
* these parts, notably for output. It has a low-resolution
@@ -171,13 +188,8 @@ static int pcf857x_probe(struct i2c_client *client)
*
* NOTE: we don't distinguish here between *4 and *4a parts.
*/
- if (strcmp(client->name, "pcf8574") == 0
- || strcmp(client->name, "pca8574") == 0
- || strcmp(client->name, "pca9670") == 0
- || strcmp(client->name, "pca9672") == 0
- || strcmp(client->name, "pca9674") == 0
- ) {
- gpio->chip.ngpio = 8;
+ gpio->chip.ngpio = id->driver_data;
+ if (gpio->chip.ngpio == 8) {
gpio->chip.direction_input = pcf857x_input8;
gpio->chip.get = pcf857x_get8;
gpio->chip.direction_output = pcf857x_output8;
@@ -197,13 +209,7 @@ static int pcf857x_probe(struct i2c_client *client)
*
* NOTE: we don't distinguish here between '75 and '75c parts.
*/
- } else if (strcmp(client->name, "pcf8575") == 0
- || strcmp(client->name, "pca8575") == 0
- || strcmp(client->name, "pca9671") == 0
- || strcmp(client->name, "pca9673") == 0
- || strcmp(client->name, "pca9675") == 0
- ) {
- gpio->chip.ngpio = 16;
+ } else if (gpio->chip.ngpio == 16) {
gpio->chip.direction_input = pcf857x_input16;
gpio->chip.get = pcf857x_get16;
gpio->chip.direction_output = pcf857x_output16;
@@ -312,6 +318,7 @@ static struct i2c_driver pcf857x_driver = {
},
.probe = pcf857x_probe,
.remove = pcf857x_remove,
+ .id_table = pcf857x_id,
};
static int __init pcf857x_init(void)
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-29 08:04:43 +0000