[2/2] 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
Cc: Christian Ruppert <christian.ruppert@alitech.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/gpio/Kconfig      |  1 +
 drivers/gpio/gpio-tb10x.c | 96 ++++++++++++---------------------------
 2 files changed, 31 insertions(+), 66 deletions(-)

Acked-by: Christian Ruppert <christian.ruppert@alitech.com>

On 06.08.2018 17:12, Linus Walleij wrote:
> 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
> Cc: Christian Ruppert <christian.ruppert@alitech.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  drivers/gpio/Kconfig      |  1 +
>  drivers/gpio/gpio-tb10x.c | 96 ++++++++++++---------------------------
>  2 files changed, 31 insertions(+), 66 deletions(-)
> 
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 7429b30e61b0..d351548d0257 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -480,6 +480,7 @@ config GPIO_SYSCON
>  
>  config GPIO_TB10X
>  	bool
> +	select GPIO_GENERIC
>  	select GENERIC_IRQ_CHIP
>  	select OF_GPIO
>  
> diff --git a/drivers/gpio/gpio-tb10x.c b/drivers/gpio/gpio-tb10x.c
> index 422b0ac5a9de..d5e5d19f4c0a 100644
> --- a/drivers/gpio/gpio-tb10x.c
> +++ b/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;
> -	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;
> -	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);
> +	/*
> +	 * 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;
> +	/*
> +	 * 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;
> +
> +	ret = devm_gpiochip_add_data(dev, &tb10x_gpio->gc, tb10x_gpio);
>  	if (ret < 0) {
>  		dev_err(dev, "Could not add gpiochip.\n");
>  		return ret;
>