ARM: S5P: Add function to register gpio interrupt bank data

This patch removes all global data from common s5p gpio interrupt
handler code. This enables to reuse this code on EXYNOS4 platform.
Instead of global data (IRQ_GPIOINT interrupt number,
S5P_GPIOINT_GROUP_MAXNR groups count), a s5p_register_gpioint_bank()
function is introduced. It is aimed to be called from gpiolib init.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/mach-s5pc100/gpiolib.c

@@ -348,6 +348,7 @@ static __init int s5pc100_gpiolib_init(void)
 	}
 
 	samsung_gpiolib_add_4bit_chips(s5pc100_gpio_chips, nr_chips);
+	s5p_register_gpioint_bank(IRQ_GPIOINT, 0, S5P_GPIOINT_GROUP_MAXNR);
 
 	return 0;
 }

arch/arm/mach-s5pv210/gpiolib.c

@@ -281,6 +281,7 @@ static __init int s5pv210_gpiolib_init(void)
 	}
 
 	samsung_gpiolib_add_4bit_chips(s5pv210_gpio_4bit, nr_chips);
+	s5p_register_gpioint_bank(IRQ_GPIOINT, 0, S5P_GPIOINT_GROUP_MAXNR);
 
 	return 0;
 }

arch/arm/plat-s5p/irq-gpioint.c

@@ -17,6 +17,7 @@
 #include <linux/irq.h>
 #include <linux/io.h>
 #include <linux/gpio.h>
+#include <linux/slab.h>
 
 #include <mach/map.h>
 #include <plat/gpio-core.h>
@@ -29,7 +30,16 @@
 #define PEND_OFFSET		0xA00
 #define REG_OFFSET(x)		((x) << 2)
 
-static struct s3c_gpio_chip *irq_chips[S5P_GPIOINT_GROUP_MAXNR];
+struct s5p_gpioint_bank {
+	struct list_head	list;
+	int			start;
+	int			nr_groups;
+	int			irq;
+	struct s3c_gpio_chip	**chips;
+	void			(*handler)(unsigned int, struct irq_desc *);
+};
+
+LIST_HEAD(banks);
 
 static int s5p_gpioint_get_offset(struct irq_data *data)
 {
@@ -139,11 +149,12 @@ static struct irq_chip s5p_gpioint = {
 
 static void s5p_gpioint_handler(unsigned int irq, struct irq_desc *desc)
 {
+	struct s5p_gpioint_bank *bank = get_irq_data(irq);
 	int group, pend_offset, mask_offset;
 	unsigned int pend, mask;
 
-	for (group = 0; group < S5P_GPIOINT_GROUP_MAXNR; group++) {
-		struct s3c_gpio_chip *chip = irq_chips[group];
+	for (group = 0; group < bank->nr_groups; group++) {
+		struct s3c_gpio_chip *chip = bank->chips[group];
 		if (!chip)
 			continue;
 
@@ -168,23 +179,44 @@ static void s5p_gpioint_handler(unsigned int irq, struct irq_desc *desc)
 static __init int s5p_gpioint_add(struct s3c_gpio_chip *chip)
 {
 	static int used_gpioint_groups = 0;
-	static bool handler_registered = 0;
 	int irq, group = chip->group;
 	int i;
+	struct s5p_gpioint_bank *bank = NULL;
 
 	if (used_gpioint_groups >= S5P_GPIOINT_GROUP_COUNT)
 		return -ENOMEM;
 
+	list_for_each_entry(bank, &banks, list) {
+		if (group >= bank->start &&
+		    group < bank->start + bank->nr_groups)
+			break;
+	}
+	if (!bank)
+		return -EINVAL;
+
+	if (!bank->handler) {
+		bank->chips = kzalloc(sizeof(struct s3c_gpio_chip *) *
+				      bank->nr_groups, GFP_KERNEL);
+		if (!bank->chips)
+			return -ENOMEM;
+
+		set_irq_chained_handler(bank->irq, s5p_gpioint_handler);
+		set_irq_data(bank->irq, bank);
+		bank->handler = s5p_gpioint_handler;
+		printk(KERN_INFO "Registered chained gpio int handler for interrupt %d.\n",
+		       bank->irq);
+	}
+
+	/*
+	 * chained GPIO irq has been sucessfully registered, allocate new gpio
+	 * int group and assign irq nubmers
+	 */
+
 	chip->irq_base = S5P_GPIOINT_BASE +
 			 used_gpioint_groups * S5P_GPIOINT_GROUP_SIZE;
 	used_gpioint_groups++;
 
-	if (!handler_registered) {
-		set_irq_chained_handler(IRQ_GPIOINT, s5p_gpioint_handler);
-		handler_registered = 1;
-	}
-
-	irq_chips[group] = chip;
+	bank->chips[group - bank->start] = chip;
 	for (i = 0; i < chip->chip.ngpio; i++) {
 		irq = chip->irq_base + i;
 		set_irq_chip(irq, &s5p_gpioint);
@@ -221,3 +253,19 @@ int __init s5p_register_gpio_interrupt(int pin)
 	}
 	return ret;
 }
+
+int __init s5p_register_gpioint_bank(int chain_irq, int start, int nr_groups)
+{
+	struct s5p_gpioint_bank *bank;
+
+	bank = kzalloc(sizeof(*bank), GFP_KERNEL);
+	if (!bank)
+		return -ENOMEM;
+
+	bank->start = start;
+	bank->nr_groups = nr_groups;
+	bank->irq = chain_irq;
+
+	list_add_tail(&bank->list, &banks);
+	return 0;
+}

arch/arm/plat-samsung/include/plat/gpio-cfg.h

@@ -225,4 +225,20 @@ extern int s5p_gpio_set_drvstr(unsigned int pin, s5p_gpio_drvstr_t drvstr);
  */
 extern int s5p_register_gpio_interrupt(int pin);
 
+/** s5p_register_gpioint_bank() - add gpio bank for further gpio interrupt
+ * registration (see s5p_register_gpio_interrupt function)
+ * @chain_irq: chained irq number for the gpio int handler for this bank
+ * @start: start gpio group number of this bank
+ * @nr_groups: number of gpio groups handled by this bank
+ *
+ * This functions registers initial information about gpio banks that
+ * can be later used by the s5p_register_gpio_interrupt() function to
+ * enable support for gpio interrupt for particular gpio group.
+ */
+#ifdef CONFIG_S5P_GPIO_INT
+extern int s5p_register_gpioint_bank(int chain_irq, int start, int nr_groups);
+#else
+#define s5p_register_gpioint_bank(chain_irq, start, nr_groups) do { } while (0)
+#endif
+
 #endif /* __PLAT_GPIO_CFG_H */