* @chip: The chip structure to be exported via gpiolib.
* @base: The base pointer to the gpio configuration registers.
* @config: special function and pull-resistor control information.
+ * @lock: Lock for exclusive access to this gpio bank.
* @pm_save: Save information for suspend/resume support.
*
* This wrapper provides the necessary information for the Samsung
* specific gpios being registered with gpiolib.
+ *
+ * The lock protects each gpio bank from multiple access of the shared
+ * configuration registers, or from reading of data whilst another thread
+ * is writing to the register set.
+ *
+ * Each chip has its own lock to avoid any contention between different
+ * CPU cores trying to get one lock for different GPIO banks, where each
+ * bank of GPIO has its own register space and configuration registers.
*/
struct s3c_gpio_chip {
struct gpio_chip chip;
struct s3c_gpio_cfg *config;
struct s3c_gpio_pm *pm;
void __iomem *base;
+ spinlock_t lock;
#ifdef CONFIG_PM
u32 pm_save[4];
#endif
extern void samsung_gpiolib_add_4bit(struct s3c_gpio_chip *chip);
extern void samsung_gpiolib_add_4bit2(struct s3c_gpio_chip *chip);
+/* exported for core SoC support to change */
+extern struct s3c_gpio_cfg s3c24xx_gpiocfg_default;
+
#ifdef CONFIG_S3C_GPIO_TRACK
extern struct s3c_gpio_chip *s3c_gpios[S3C_GPIO_END];
#define __gpio_pm(x) NULL
#endif /* CONFIG_PM */
+
+/* locking wrappers to deal with multiple access to the same gpio bank */
+#define s3c_gpio_lock(_oc, _fl) spin_lock_irqsave(&(_oc)->lock, _fl)
+#define s3c_gpio_unlock(_oc, _fl) spin_unlock_irqrestore(&(_oc)->lock, _fl)