gpio: tb10x: Use GENERIC_GPIO

Instead of open coding logic for reading and writing GPIO lines,
use the generic GPIO library. Also switch to using the spinlock
from the generic GPIO to protect the registers.

Cc: linux-snps-arc@lists.infradead.org
Acked-by: Christian Ruppert <christian.ruppert@alitech.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/Kconfig

@@ -480,6 +480,7 @@ config GPIO_SYSCON
 
 config GPIO_TB10X
 	bool
+	select GPIO_GENERIC
 	select GENERIC_IRQ_CHIP
 	select OF_GPIO
 

drivers/gpio/gpio-tb10x.c

@@ -45,14 +45,12 @@
 
 
 /**
- * @spinlock: used for atomic read/modify/write of registers
  * @base: register base address
  * @domain: IRQ domain of GPIO generated interrupts managed by this controller
  * @irq: Interrupt line of parent interrupt controller
  * @gc: gpio_chip structure associated to this GPIO controller
  */
 struct tb10x_gpio {
-	spinlock_t spinlock;
 	void __iomem *base;
 	struct irq_domain *domain;
 	int irq;
@@ -76,60 +74,14 @@ static inline void tb10x_set_bits(struct tb10x_gpio *gpio, unsigned int offs,
 	u32 r;
 	unsigned long flags;
 
-	spin_lock_irqsave(&gpio->spinlock, flags);
+	spin_lock_irqsave(&gpio->gc.bgpio_lock, flags);
 
 	r = tb10x_reg_read(gpio, offs);
 	r = (r & ~mask) | (val & mask);
 
 	tb10x_reg_write(gpio, offs, r);
 
-	spin_unlock_irqrestore(&gpio->spinlock, flags);
-}
-
-static int tb10x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
-{
-	struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
-	int mask = BIT(offset);
-	int val = TB10X_GPIO_DIR_IN << offset;
-
-	tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val);
-
-	return 0;
-}
-
-static int tb10x_gpio_get(struct gpio_chip *chip, unsigned offset)
-{
-	struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
-	int val;
-
-	val = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_DATA);
-
-	if (val & BIT(offset))
-		return 1;
-	else
-		return 0;
-}
-
-static void tb10x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
-{
-	struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
-	int mask = BIT(offset);
-	int val = value << offset;
-
-	tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DATA, mask, val);
-}
-
-static int tb10x_gpio_direction_out(struct gpio_chip *chip,
-					unsigned offset, int value)
-{
-	struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
-	int mask = BIT(offset);
-	int val = TB10X_GPIO_DIR_OUT << offset;
-
-	tb10x_gpio_set(chip, offset, value);
-	tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val);
-
-	return 0;
+	spin_unlock_irqrestore(&gpio->gc.bgpio_lock, flags);
 }
 
 static int tb10x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
@@ -184,8 +136,6 @@ static int tb10x_gpio_probe(struct platform_device *pdev)
 	if (tb10x_gpio == NULL)
 		return -ENOMEM;
 
-	spin_lock_init(&tb10x_gpio->spinlock);
-
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	tb10x_gpio->base = devm_ioremap_resource(dev, mem);
 	if (IS_ERR(tb10x_gpio->base))
@@ -196,20 +146,34 @@ static int tb10x_gpio_probe(struct platform_device *pdev)
 	if (!tb10x_gpio->gc.label)
 		return -ENOMEM;
 
-	tb10x_gpio->gc.parent		= &pdev->dev;
+	/*
+	 * Initialize generic GPIO with one single register for reading and setting
+	 * the lines, no special set or clear registers and a data direction register
+	 * wher 1 means "output".
+	 */
+	ret = bgpio_init(&tb10x_gpio->gc, dev, 4,
+			 tb10x_gpio->base + OFFSET_TO_REG_DATA,
+			 NULL,
+			 NULL,
+			 tb10x_gpio->base + OFFSET_TO_REG_DDR,
+			 NULL,
+			 0);
+	if (ret) {
+		dev_err(dev, "unable to init generic GPIO\n");
+		return ret;
+	}
+	tb10x_gpio->gc.base = -1;
+	tb10x_gpio->gc.parent = dev;
 	tb10x_gpio->gc.owner = THIS_MODULE;
-	tb10x_gpio->gc.direction_input	= tb10x_gpio_direction_in;
-	tb10x_gpio->gc.get		= tb10x_gpio_get;
-	tb10x_gpio->gc.direction_output	= tb10x_gpio_direction_out;
-	tb10x_gpio->gc.set		= tb10x_gpio_set;
+	/*
+	 * ngpio is set by bgpio_init() but we override it, this .request()
+	 * callback also overrides the one set up by generic GPIO.
+	 */
+	tb10x_gpio->gc.ngpio = ngpio;
 	tb10x_gpio->gc.request = gpiochip_generic_request;
 	tb10x_gpio->gc.free = gpiochip_generic_free;
-	tb10x_gpio->gc.base		= -1;
-	tb10x_gpio->gc.ngpio		= ngpio;
-	tb10x_gpio->gc.can_sleep	= false;
-
 
-	ret = devm_gpiochip_add_data(&pdev->dev, &tb10x_gpio->gc, tb10x_gpio);
+	ret = devm_gpiochip_add_data(dev, &tb10x_gpio->gc, tb10x_gpio);
 	if (ret < 0) {
 		dev_err(dev, "Could not add gpiochip.\n");
 		return ret;