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path: root/drivers/staging/dream/generic_gpio.c
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-rw-r--r--drivers/staging/dream/generic_gpio.c274
1 files changed, 274 insertions, 0 deletions
diff --git a/drivers/staging/dream/generic_gpio.c b/drivers/staging/dream/generic_gpio.c
new file mode 100644
index 000000000000..fe24d38345d0
--- /dev/null
+++ b/drivers/staging/dream/generic_gpio.c
@@ -0,0 +1,274 @@
+/* arch/arm/mach-msm/generic_gpio.c
+ *
+ * Copyright (C) 2007 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <asm/gpio.h>
+#include "gpio_chip.h"
+
+#define GPIO_NUM_TO_CHIP_INDEX(gpio) ((gpio)>>5)
+
+struct gpio_state {
+ unsigned long flags;
+ int refcount;
+};
+
+static DEFINE_SPINLOCK(gpio_chips_lock);
+static LIST_HEAD(gpio_chip_list);
+static struct gpio_chip **gpio_chip_array;
+static unsigned long gpio_chip_array_size;
+
+int register_gpio_chip(struct gpio_chip *new_gpio_chip)
+{
+ int err = 0;
+ struct gpio_chip *gpio_chip;
+ int i;
+ unsigned long irq_flags;
+ unsigned int chip_array_start_index, chip_array_end_index;
+
+ new_gpio_chip->state = kzalloc((new_gpio_chip->end + 1 - new_gpio_chip->start) * sizeof(new_gpio_chip->state[0]), GFP_KERNEL);
+ if (new_gpio_chip->state == NULL) {
+ printk(KERN_ERR "register_gpio_chip: failed to allocate state\n");
+ return -ENOMEM;
+ }
+
+ spin_lock_irqsave(&gpio_chips_lock, irq_flags);
+ chip_array_start_index = GPIO_NUM_TO_CHIP_INDEX(new_gpio_chip->start);
+ chip_array_end_index = GPIO_NUM_TO_CHIP_INDEX(new_gpio_chip->end);
+ if (chip_array_end_index >= gpio_chip_array_size) {
+ struct gpio_chip **new_gpio_chip_array;
+ unsigned long new_gpio_chip_array_size = chip_array_end_index + 1;
+
+ new_gpio_chip_array = kmalloc(new_gpio_chip_array_size * sizeof(new_gpio_chip_array[0]), GFP_ATOMIC);
+ if (new_gpio_chip_array == NULL) {
+ printk(KERN_ERR "register_gpio_chip: failed to allocate array\n");
+ err = -ENOMEM;
+ goto failed;
+ }
+ for (i = 0; i < gpio_chip_array_size; i++)
+ new_gpio_chip_array[i] = gpio_chip_array[i];
+ for (i = gpio_chip_array_size; i < new_gpio_chip_array_size; i++)
+ new_gpio_chip_array[i] = NULL;
+ gpio_chip_array = new_gpio_chip_array;
+ gpio_chip_array_size = new_gpio_chip_array_size;
+ }
+ list_for_each_entry(gpio_chip, &gpio_chip_list, list) {
+ if (gpio_chip->start > new_gpio_chip->end) {
+ list_add_tail(&new_gpio_chip->list, &gpio_chip->list);
+ goto added;
+ }
+ if (gpio_chip->end >= new_gpio_chip->start) {
+ printk(KERN_ERR "register_gpio_source %u-%u overlaps with %u-%u\n",
+ new_gpio_chip->start, new_gpio_chip->end,
+ gpio_chip->start, gpio_chip->end);
+ err = -EBUSY;
+ goto failed;
+ }
+ }
+ list_add_tail(&new_gpio_chip->list, &gpio_chip_list);
+added:
+ for (i = chip_array_start_index; i <= chip_array_end_index; i++) {
+ if (gpio_chip_array[i] == NULL || gpio_chip_array[i]->start > new_gpio_chip->start)
+ gpio_chip_array[i] = new_gpio_chip;
+ }
+failed:
+ spin_unlock_irqrestore(&gpio_chips_lock, irq_flags);
+ if (err)
+ kfree(new_gpio_chip->state);
+ return err;
+}
+
+static struct gpio_chip *get_gpio_chip_locked(unsigned int gpio)
+{
+ unsigned long i;
+ struct gpio_chip *chip;
+
+ i = GPIO_NUM_TO_CHIP_INDEX(gpio);
+ if (i >= gpio_chip_array_size)
+ return NULL;
+ chip = gpio_chip_array[i];
+ if (chip == NULL)
+ return NULL;
+ list_for_each_entry_from(chip, &gpio_chip_list, list) {
+ if (gpio < chip->start)
+ return NULL;
+ if (gpio <= chip->end)
+ return chip;
+ }
+ return NULL;
+}
+
+static int request_gpio(unsigned int gpio, unsigned long flags)
+{
+ int err = 0;
+ struct gpio_chip *chip;
+ unsigned long irq_flags;
+ unsigned long chip_index;
+
+ spin_lock_irqsave(&gpio_chips_lock, irq_flags);
+ chip = get_gpio_chip_locked(gpio);
+ if (chip == NULL) {
+ err = -EINVAL;
+ goto err;
+ }
+ chip_index = gpio - chip->start;
+ if (chip->state[chip_index].refcount == 0) {
+ chip->configure(chip, gpio, flags);
+ chip->state[chip_index].flags = flags;
+ chip->state[chip_index].refcount++;
+ } else if ((flags & IRQF_SHARED) && (chip->state[chip_index].flags & IRQF_SHARED))
+ chip->state[chip_index].refcount++;
+ else
+ err = -EBUSY;
+err:
+ spin_unlock_irqrestore(&gpio_chips_lock, irq_flags);
+ return err;
+}
+
+int gpio_request(unsigned gpio, const char *label)
+{
+ return request_gpio(gpio, 0);
+}
+EXPORT_SYMBOL(gpio_request);
+
+void gpio_free(unsigned gpio)
+{
+ struct gpio_chip *chip;
+ unsigned long irq_flags;
+ unsigned long chip_index;
+
+ spin_lock_irqsave(&gpio_chips_lock, irq_flags);
+ chip = get_gpio_chip_locked(gpio);
+ if (chip) {
+ chip_index = gpio - chip->start;
+ chip->state[chip_index].refcount--;
+ }
+ spin_unlock_irqrestore(&gpio_chips_lock, irq_flags);
+}
+EXPORT_SYMBOL(gpio_free);
+
+static int gpio_get_irq_num(unsigned int gpio, unsigned int *irqp, unsigned long *irqnumflagsp)
+{
+ int ret = -ENOTSUPP;
+ struct gpio_chip *chip;
+ unsigned long irq_flags;
+
+ spin_lock_irqsave(&gpio_chips_lock, irq_flags);
+ chip = get_gpio_chip_locked(gpio);
+ if (chip && chip->get_irq_num)
+ ret = chip->get_irq_num(chip, gpio, irqp, irqnumflagsp);
+ spin_unlock_irqrestore(&gpio_chips_lock, irq_flags);
+ return ret;
+}
+
+int gpio_to_irq(unsigned gpio)
+{
+ int ret, irq;
+ ret = gpio_get_irq_num(gpio, &irq, NULL);
+ if (ret)
+ return ret;
+ return irq;
+}
+EXPORT_SYMBOL(gpio_to_irq);
+
+int gpio_configure(unsigned int gpio, unsigned long flags)
+{
+ int ret = -ENOTSUPP;
+ struct gpio_chip *chip;
+ unsigned long irq_flags;
+
+ spin_lock_irqsave(&gpio_chips_lock, irq_flags);
+ chip = get_gpio_chip_locked(gpio);
+ if (chip)
+ ret = chip->configure(chip, gpio, flags);
+ spin_unlock_irqrestore(&gpio_chips_lock, irq_flags);
+ return ret;
+}
+EXPORT_SYMBOL(gpio_configure);
+
+int gpio_direction_input(unsigned gpio)
+{
+ return gpio_configure(gpio, GPIOF_INPUT);
+}
+EXPORT_SYMBOL(gpio_direction_input);
+
+int gpio_direction_output(unsigned gpio, int value)
+{
+ gpio_set_value(gpio, value);
+ return gpio_configure(gpio, GPIOF_DRIVE_OUTPUT);
+}
+EXPORT_SYMBOL(gpio_direction_output);
+
+int gpio_get_value(unsigned gpio)
+{
+ int ret = -ENOTSUPP;
+ struct gpio_chip *chip;
+ unsigned long irq_flags;
+
+ spin_lock_irqsave(&gpio_chips_lock, irq_flags);
+ chip = get_gpio_chip_locked(gpio);
+ if (chip && chip->read)
+ ret = chip->read(chip, gpio);
+ spin_unlock_irqrestore(&gpio_chips_lock, irq_flags);
+ return ret;
+}
+EXPORT_SYMBOL(gpio_get_value);
+
+void gpio_set_value(unsigned gpio, int on)
+{
+ int ret = -ENOTSUPP;
+ struct gpio_chip *chip;
+ unsigned long irq_flags;
+
+ spin_lock_irqsave(&gpio_chips_lock, irq_flags);
+ chip = get_gpio_chip_locked(gpio);
+ if (chip && chip->write)
+ ret = chip->write(chip, gpio, on);
+ spin_unlock_irqrestore(&gpio_chips_lock, irq_flags);
+}
+EXPORT_SYMBOL(gpio_set_value);
+
+int gpio_read_detect_status(unsigned int gpio)
+{
+ int ret = -ENOTSUPP;
+ struct gpio_chip *chip;
+ unsigned long irq_flags;
+
+ spin_lock_irqsave(&gpio_chips_lock, irq_flags);
+ chip = get_gpio_chip_locked(gpio);
+ if (chip && chip->read_detect_status)
+ ret = chip->read_detect_status(chip, gpio);
+ spin_unlock_irqrestore(&gpio_chips_lock, irq_flags);
+ return ret;
+}
+EXPORT_SYMBOL(gpio_read_detect_status);
+
+int gpio_clear_detect_status(unsigned int gpio)
+{
+ int ret = -ENOTSUPP;
+ struct gpio_chip *chip;
+ unsigned long irq_flags;
+
+ spin_lock_irqsave(&gpio_chips_lock, irq_flags);
+ chip = get_gpio_chip_locked(gpio);
+ if (chip && chip->clear_detect_status)
+ ret = chip->clear_detect_status(chip, gpio);
+ spin_unlock_irqrestore(&gpio_chips_lock, irq_flags);
+ return ret;
+}
+EXPORT_SYMBOL(gpio_clear_detect_status);