linux-kernel - Re: [PATCH V2 2/2] mfd: max77620: Mask/unmask interrupt before/after servicing it

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Message-ID: <20160610145915.GD7351@dell>
Date:	Fri, 10 Jun 2016 15:59:15 +0100
From:	Lee Jones <lee.jones@...aro.org>
To:	Laxman Dewangan <ldewangan@...dia.com>
Cc:	broonie@...nel.org, gregkh@...uxfoundation.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH V2 2/2] mfd: max77620: Mask/unmask interrupt before/after
 servicing it

On Thu, 09 Jun 2016, Laxman Dewangan wrote:

> The programming guidelines of the MAX77620 for servicing interrupt is:
> 1. When interrupt occurs from PMIC, mask the PMIC interrupt by
>    setting GLBLM.
> 2. Read IRQTOP and service the interrupt.
> 3. Once all interrupts has been checked and serviced, the interrupt
>    service routine un-masks the hardware interrupt line by clearing
>    GLBLM.
> 
> Add the pre and post interrupt service handler for mask and unmask the
> global interrupt mask bit (for step 1 and 3) as callback from regmap-irq.
> 
> Signed-off-by: Laxman Dewangan <ldewangan@...dia.com>
> 
> ---
> Changes from V1:
> - Rename pre/post handler to max77620_irq_{mask/unmask}
> - Change commit description to say mask/unamsk clearly.
> 
>  drivers/mfd/max77620.c | 55 +++++++++++++++++++++++++++++++++++++++++---------
>  1 file changed, 46 insertions(+), 9 deletions(-)

Applied, thanks.

> diff --git a/drivers/mfd/max77620.c b/drivers/mfd/max77620.c
> index f32fbb8..6005fe2 100644
> --- a/drivers/mfd/max77620.c
> +++ b/drivers/mfd/max77620.c
> @@ -111,15 +111,6 @@ static const struct mfd_cell max20024_children[] = {
>  	},
>  };
>  
> -static struct regmap_irq_chip max77620_top_irq_chip = {
> -	.name = "max77620-top",
> -	.irqs = max77620_top_irqs,
> -	.num_irqs = ARRAY_SIZE(max77620_top_irqs),
> -	.num_regs = 2,
> -	.status_base = MAX77620_REG_IRQTOP,
> -	.mask_base = MAX77620_REG_IRQTOPM,
> -};
> -
>  static const struct regmap_range max77620_readable_ranges[] = {
>  	regmap_reg_range(MAX77620_REG_CNFGGLBL1, MAX77620_REG_DVSSD4),
>  };
> @@ -180,6 +171,51 @@ static const struct regmap_config max20024_regmap_config = {
>  	.volatile_table = &max77620_volatile_table,
>  };
>  
> +/*
> + * MAX77620 and MAX20024 has the following steps of the interrupt handling
> + * for TOP interrupts:
> + * 1. When interrupt occurs from PMIC, mask the PMIC interrupt by setting GLBLM.
> + * 2. Read IRQTOP and service the interrupt.
> + * 3. Once all interrupts has been checked and serviced, the interrupt service
> + *    routine un-masks the hardware interrupt line by clearing GLBLM.
> + */
> +static int max77620_irq_global_mask(void *irq_drv_data)
> +{
> +	struct max77620_chip *chip = irq_drv_data;
> +	int ret;
> +
> +	ret = regmap_update_bits(chip->rmap, MAX77620_REG_INTENLBT,
> +				 MAX77620_GLBLM_MASK, MAX77620_GLBLM_MASK);
> +	if (ret < 0)
> +		dev_err(chip->dev, "Failed to set GLBLM: %d\n", ret);
> +
> +	return ret;
> +}
> +
> +static int max77620_irq_global_unmask(void *irq_drv_data)
> +{
> +	struct max77620_chip *chip = irq_drv_data;
> +	int ret;
> +
> +	ret = regmap_update_bits(chip->rmap, MAX77620_REG_INTENLBT,
> +				 MAX77620_GLBLM_MASK, 0);
> +	if (ret < 0)
> +		dev_err(chip->dev, "Failed to reset GLBLM: %d\n", ret);
> +
> +	return ret;
> +}
> +
> +static struct regmap_irq_chip max77620_top_irq_chip = {
> +	.name = "max77620-top",
> +	.irqs = max77620_top_irqs,
> +	.num_irqs = ARRAY_SIZE(max77620_top_irqs),
> +	.num_regs = 2,
> +	.status_base = MAX77620_REG_IRQTOP,
> +	.mask_base = MAX77620_REG_IRQTOPM,
> +	.handle_pre_irq = max77620_irq_global_mask,
> +	.handle_post_irq = max77620_irq_global_unmask,
> +};
> +
>  /* max77620_get_fps_period_reg_value:  Get FPS bit field value from
>   *				       requested periods.
>   * MAX77620 supports the FPS period of 40, 80, 160, 320, 540, 1280, 2560
> @@ -433,6 +469,7 @@ static int max77620_probe(struct i2c_client *client,
>  	if (ret < 0)
>  		return ret;
>  
> +	max77620_top_irq_chip.irq_drv_data = chip;
>  	ret = devm_regmap_add_irq_chip(chip->dev, chip->rmap, client->irq,
>  				       IRQF_ONESHOT | IRQF_SHARED,
>  				       chip->irq_base, &max77620_top_irq_chip,

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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