gpio: davinci: Add support for multiple GPIO controllers

Update GPIO driver to support Multiple GPIO controllers by updating
the base of subsequent GPIO chips with total of previous chips
gpio count so that gpio_add_chip gets unique numbers.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-davinci.c

@@ -186,7 +186,7 @@ static int davinci_gpio_of_xlate(struct gpio_chip *gc,
 
 static int davinci_gpio_probe(struct platform_device *pdev)
 {
-	static int ctrl_num;
+	static int ctrl_num, bank_base;
 	int gpio, bank;
 	unsigned ngpio, nbank;
 	struct davinci_gpio_controller *chips;
@@ -240,6 +240,7 @@ static int davinci_gpio_probe(struct platform_device *pdev)
 	chips->chip.set = davinci_gpio_set;
 
 	chips->chip.ngpio = ngpio;
+	chips->chip.base = bank_base;
 
 #ifdef CONFIG_OF_GPIO
 	chips->chip.of_gpio_n_cells = 2;
@@ -248,6 +249,7 @@ static int davinci_gpio_probe(struct platform_device *pdev)
 	chips->chip.of_node = dev->of_node;
 #endif
 	spin_lock_init(&chips->lock);
+	bank_base += ngpio;
 
 	for (gpio = 0, bank = 0; gpio < ngpio; gpio += 32, bank++)
 		chips->regs[bank] = gpio_base + offset_array[bank];

include/linux/platform_data/gpio-davinci.h

@@ -42,6 +42,7 @@ struct davinci_gpio_controller {
 	void __iomem		*regs[MAX_REGS_BANKS];
 	int			gpio_unbanked;
 	unsigned int		base_irq;
+	unsigned int		base;
 };
 
 /*