gpio: davinci: Use unique labels for each gpio chip

The gpiod framework uses the chip label to match a specific chip.
The davinci gpio driver, creates several chips using always the same
label, which is not compatible with gpiod.

To allow platform data to declare gpio lookup tables, and for drivers
to use the gpiod framework, allocate unique label per registered chip.
Signed-off-by: Axel Haslam <ahaslam@baylibre.com>
Reviewed-by: Sekhar Nori <nsekhar@ti.com>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-davinci.c

@@ -40,6 +40,7 @@ struct davinci_gpio_regs {
 typedef struct irq_chip *(*gpio_get_irq_chip_cb_t)(unsigned int irq);
 
 #define BINTEN	0x8 /* GPIO Interrupt Per-Bank Enable Register */
+#define MAX_LABEL_SIZE 20
 
 static void __iomem *gpio_base;
 
@@ -201,6 +202,7 @@ static int davinci_gpio_probe(struct platform_device *pdev)
 	struct davinci_gpio_regs __iomem *regs;
 	struct device *dev = &pdev->dev;
 	struct resource *res;
+	char label[MAX_LABEL_SIZE];
 
 	pdata = davinci_gpio_get_pdata(pdev);
 	if (!pdata) {
@@ -237,7 +239,10 @@ static int davinci_gpio_probe(struct platform_device *pdev)
 		return PTR_ERR(gpio_base);
 
 	for (i = 0, base = 0; base < ngpio; i++, base += 32) {
-		chips[i].chip.label = "DaVinci";
+		snprintf(label, MAX_LABEL_SIZE, "davinci_gpio.%d", i);
+		chips[i].chip.label = devm_kstrdup(dev, label, GFP_KERNEL);
+		if (!chips[i].chip.label)
+			return -ENOMEM;
 
 		chips[i].chip.direction_input = davinci_direction_in;
 		chips[i].chip.get = davinci_gpio_get;