Re: [PATCH v2 07/10] ARM: OMAP1: ams-delta FIQ: Keep serio input GPIOs requested

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Fri, Jun 22, 2018 at 12:41:25AM +0200, Janusz Krzysztofik wrote:
> From the very beginning, input GPIO pins of ams-delta serio port have
> been used by FIQ handler, not serio driver.
> 
> Don't request those pins from the ams-delta-serio driver any longer,
> instead keep them requested and initialized by the FIQ initialization
> routine which already requests them and releases while identifying GPIO
> IRQs.
> 
> Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>

Input bits look good.

Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

> ---
> Changelog:
> v2: rebased on v4.18-rc1, no conflicts
> 
>  arch/arm/mach-omap1/ams-delta-fiq.c   | 42 ++++++++++++++++++++++++++++++-----
>  drivers/input/serio/ams_delta_serio.c | 30 ++-----------------------
>  2 files changed, 39 insertions(+), 33 deletions(-)
> 
> diff --git a/arch/arm/mach-omap1/ams-delta-fiq.c b/arch/arm/mach-omap1/ams-delta-fiq.c
> index 1d54a6177f14..5a6c59ac9b5f 100644
> --- a/arch/arm/mach-omap1/ams-delta-fiq.c
> +++ b/arch/arm/mach-omap1/ams-delta-fiq.c
> @@ -45,6 +45,11 @@ static struct irq_chip *irq_chip;
>  static struct irq_data *irq_data[16];
>  static unsigned int irq_counter[16];
>  
> +static const char *pin_name[16] __initconst = {
> +	[AMS_DELTA_GPIO_PIN_KEYBRD_DATA]	= "keybrd_data",
> +	[AMS_DELTA_GPIO_PIN_KEYBRD_CLK]		= "keybrd_clk",
> +};
> +
>  static irqreturn_t deferred_fiq(int irq, void *dev_id)
>  {
>  	struct irq_data *d;
> @@ -80,7 +85,7 @@ static irqreturn_t deferred_fiq(int irq, void *dev_id)
>  
>  void __init ams_delta_init_fiq(struct gpio_chip *chip)
>  {
> -	struct gpio_desc *gpiod;
> +	struct gpio_desc *gpiod, *data = NULL, *clk = NULL;
>  	void *fiqhandler_start;
>  	unsigned int fiqhandler_length;
>  	struct pt_regs FIQ_regs;
> @@ -96,7 +101,7 @@ void __init ams_delta_init_fiq(struct gpio_chip *chip)
>  	}
>  
>  	for (i = 0; i < ARRAY_SIZE(irq_data); i++) {
> -		gpiod = gpiochip_request_own_desc(chip, i, NULL);
> +		gpiod = gpiochip_request_own_desc(chip, i, pin_name[i]);
>  		if (IS_ERR(gpiod)) {
>  			pr_err("%s: failed to get GPIO pin %d (%ld)\n",
>  			       __func__, i, PTR_ERR(gpiod));
> @@ -105,8 +110,27 @@ void __init ams_delta_init_fiq(struct gpio_chip *chip)
>  		/* Store irq_data location for IRQ handler use */
>  		irq_data[i] = irq_get_irq_data(gpiod_to_irq(gpiod));
>  
> -		gpiochip_free_own_desc(gpiod);
> +		/*
> +		 * FIQ handler takes full control over serio data and clk GPIO
> +		 * pins.  Initiaize them and keep requested so nobody can
> +		 * interfere.  Fail if any of those two couldn't be requested.
> +		 */
> +		switch (i) {
> +		case AMS_DELTA_GPIO_PIN_KEYBRD_DATA:
> +			data = gpiod;
> +			gpiod_direction_input(data);
> +			break;
> +		case AMS_DELTA_GPIO_PIN_KEYBRD_CLK:
> +			clk = gpiod;
> +			gpiod_direction_input(clk);
> +			break;
> +		default:
> +			gpiochip_free_own_desc(gpiod);
> +			break;
> +		}
>  	}
> +	if (!data || !clk)
> +		goto out_gpio;
>  
>  	fiqhandler_start = &qwerty_fiqin_start;
>  	fiqhandler_length = &qwerty_fiqin_end - &qwerty_fiqin_start;
> @@ -117,7 +141,7 @@ void __init ams_delta_init_fiq(struct gpio_chip *chip)
>  	if (retval) {
>  		pr_err("ams_delta_init_fiq(): couldn't claim FIQ, ret=%d\n",
>  				retval);
> -		return;
> +		goto out_gpio;
>  	}
>  
>  	retval = request_irq(INT_DEFERRED_FIQ, deferred_fiq,
> @@ -125,7 +149,7 @@ void __init ams_delta_init_fiq(struct gpio_chip *chip)
>  	if (retval < 0) {
>  		pr_err("Failed to get deferred_fiq IRQ, ret=%d\n", retval);
>  		release_fiq(&fh);
> -		return;
> +		goto out_gpio;
>  	}
>  	/*
>  	 * Since no set_type() method is provided by OMAP irq chip,
> @@ -175,4 +199,12 @@ void __init ams_delta_init_fiq(struct gpio_chip *chip)
>  	offset = IRQ_ILR0_REG_OFFSET + (INT_GPIO_BANK1 - NR_IRQS_LEGACY) * 0x4;
>  	val = omap_readl(OMAP_IH1_BASE + offset) | 1;
>  	omap_writel(val, OMAP_IH1_BASE + offset);
> +
> +	return;
> +
> +out_gpio:
> +	if (data)
> +		gpiochip_free_own_desc(data);
> +	if (clk)
> +		gpiochip_free_own_desc(clk);
>  }
> diff --git a/drivers/input/serio/ams_delta_serio.c b/drivers/input/serio/ams_delta_serio.c
> index b955c6a72e99..7952a29f9540 100644
> --- a/drivers/input/serio/ams_delta_serio.c
> +++ b/drivers/input/serio/ams_delta_serio.c
> @@ -110,19 +110,6 @@ static void ams_delta_serio_close(struct serio *serio)
>  	regulator_disable(priv->vcc);
>  }
>  
> -static const struct gpio ams_delta_gpios[] __initconst_or_module = {
> -	{
> -		.gpio	= AMS_DELTA_GPIO_PIN_KEYBRD_DATA,
> -		.flags	= GPIOF_DIR_IN,
> -		.label	= "serio-data",
> -	},
> -	{
> -		.gpio	= AMS_DELTA_GPIO_PIN_KEYBRD_CLK,
> -		.flags	= GPIOF_DIR_IN,
> -		.label	= "serio-clock",
> -	},
> -};
> -
>  static int ams_delta_serio_init(struct platform_device *pdev)
>  {
>  	struct ams_delta_serio *priv;
> @@ -133,13 +120,6 @@ static int ams_delta_serio_init(struct platform_device *pdev)
>  	if (!priv)
>  		return -ENOMEM;
>  
> -	err = gpio_request_array(ams_delta_gpios,
> -				ARRAY_SIZE(ams_delta_gpios));
> -	if (err) {
> -		dev_err(&pdev->dev, "Couldn't request gpio pins\n");
> -		goto serio;
> -	}
> -
>  	priv->vcc = devm_regulator_get(&pdev->dev, "vcc");
>  	if (IS_ERR(priv->vcc)) {
>  		err = PTR_ERR(priv->vcc);
> @@ -157,7 +137,7 @@ static int ams_delta_serio_init(struct platform_device *pdev)
>  		 */
>  		if (err == -ENODEV)
>  			err = -EPROBE_DEFER;
> -		goto gpio;
> +		return err;
>  	}
>  
>  	err = request_irq(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK),
> @@ -165,7 +145,7 @@ static int ams_delta_serio_init(struct platform_device *pdev)
>  			DRIVER_NAME, priv);
>  	if (err < 0) {
>  		dev_err(&pdev->dev, "IRQ request failed (%d)\n", err);
> -		goto gpio;
> +		return err;
>  	}
>  	/*
>  	 * Since GPIO register handling for keyboard clock pin is performed
> @@ -201,10 +181,6 @@ static int ams_delta_serio_init(struct platform_device *pdev)
>  
>  irq:
>  	free_irq(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK), priv);
> -gpio:
> -	gpio_free_array(ams_delta_gpios,
> -			ARRAY_SIZE(ams_delta_gpios));
> -serio:
>  	return err;
>  }
>  
> @@ -214,8 +190,6 @@ static int ams_delta_serio_exit(struct platform_device *pdev)
>  
>  	serio_unregister_port(priv->serio);
>  	free_irq(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK), 0);
> -	gpio_free_array(ams_delta_gpios,
> -			ARRAY_SIZE(ams_delta_gpios));
>  
>  	return 0;
>  }
> -- 
> 2.16.4
> 

-- 
Dmitry