Re: [PATCH v2 7/8] mfd: intel_soc_pmic_bxtwc: use chained irqs for second level irq chips

[Lee Jones]

On Fri, 14 Apr 2017, sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx wrote:

> From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
> 
> Whishkey cove PMIC has support to mask/unmask interrupts at two levels.
> At first level we can mask/unmask interrupt domains like TMU, GPIO, ADC,
> CHGR, BCU THERMAL and PWRBTN and at second level, it provides facility
> to mask/unmask individual interrupts belong each of this domain. For
> example, in case of TMU, at first level we have TMU interrupt domain,
> and at second level we have two interrupts, wake alarm, system alarm that
> belong to the TMU interrupt domain.
> 
> Currently, in this driver all first level irqs are registered as part of
> irq chip(bxtwc_regmap_irq_chip). By default, after you register the irq
> chip from your driver, all irqs in that chip will masked and can only be
> enabled if that irq is requested using request_irq call. This is the
> default Linux irq behavior model. And whenever a dependent device that
> belongs to PMIC requests only the second level irq and not explicitly
> unmask the first level irq, then in essence the second level irq will
> still be disabled. For example, if TMU device driver request wake_alarm
> irq and not explicitly unmask TMU level 1 irq then according to the default
> Linux irq model,  wake_alarm irq will still be disabled. So the proper
> solution to fix this issue is to use the chained irq chip concept. We
> should chain all the second level chip irqs to the corresponding first
> level irq. To do this, we need to create separate irq chips for every
> group of second level irqs.
> 
> In case of TMU, when adding second level irq chip, instead of using pmic
> irq we should use the corresponding first level irq. So the following
> code will change from
> 
> ret = regmap_add_irq_chip(pmic->regmap, pmic->irq, ...)
> 
> to,
> 
> virq = regmap_irq_get_virq(&pmic->irq_chip_data, BXTWC_TMU_LVL1_IRQ);
> 
> ret = regmap_add_irq_chip(pmic->regmap, virq, ...)
> 
> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
> ---
>  drivers/mfd/intel_soc_pmic_bxtwc.c | 174 +++++++++++++++++++++++++++++--------
>  include/linux/mfd/intel_soc_pmic.h |   5 +-
>  2 files changed, 144 insertions(+), 35 deletions(-)

For my own reference:
  Acked-for-MFD-by: Lee Jones <lee.jones@xxxxxxxxxx>
  
> Changes since v1:
>  * Rebased on top of dev_* cleanup patch.
>  * Fixed style & grammer issues reported by Lee Jones
> 
> diff --git a/drivers/mfd/intel_soc_pmic_bxtwc.c b/drivers/mfd/intel_soc_pmic_bxtwc.c
> index 442dc29..9a04187 100644
> --- a/drivers/mfd/intel_soc_pmic_bxtwc.c
> +++ b/drivers/mfd/intel_soc_pmic_bxtwc.c
> @@ -81,18 +81,26 @@ enum bxtwc_irqs {
>  	BXTWC_PWRBTN_IRQ,
>  };
>  
> -enum bxtwc_irqs_level2 {
> -	/* Level 2 */
> +enum bxtwc_irqs_tmu {
> +	BXTWC_TMU_IRQ = 0,
> +};
> +
> +enum bxtwc_irqs_bcu {
>  	BXTWC_BCU_IRQ = 0,
> -	BXTWC_ADC_IRQ,
> -	BXTWC_USBC_IRQ,
> +};
> +
> +enum bxtwc_irqs_adc {
> +	BXTWC_ADC_IRQ = 0,
> +};
> +
> +enum bxtwc_irqs_chgr {
> +	BXTWC_USBC_IRQ = 0,
>  	BXTWC_CHGR0_IRQ,
>  	BXTWC_CHGR1_IRQ,
> -	BXTWC_CRIT_IRQ,
>  };
>  
> -enum bxtwc_irqs_tmu {
> -	BXTWC_TMU_IRQ = 0,
> +enum bxtwc_irqs_crit {
> +	BXTWC_CRIT_IRQ = 0,
>  };
>  
>  static const struct regmap_irq bxtwc_regmap_irqs[] = {
> @@ -107,17 +115,26 @@ static const struct regmap_irq bxtwc_regmap_irqs[] = {
>  	REGMAP_IRQ_REG(BXTWC_PWRBTN_IRQ, 1, 0x03),
>  };
>  
> -static const struct regmap_irq bxtwc_regmap_irqs_level2[] = {
> +static const struct regmap_irq bxtwc_regmap_irqs_tmu[] = {
> +	REGMAP_IRQ_REG(BXTWC_TMU_IRQ, 0, 0x06),
> +};
> +
> +static const struct regmap_irq bxtwc_regmap_irqs_bcu[] = {
>  	REGMAP_IRQ_REG(BXTWC_BCU_IRQ, 0, 0x1f),
> -	REGMAP_IRQ_REG(BXTWC_ADC_IRQ, 1, 0xff),
> -	REGMAP_IRQ_REG(BXTWC_USBC_IRQ, 2, BIT(5)),
> -	REGMAP_IRQ_REG(BXTWC_CHGR0_IRQ, 2, 0x1f),
> -	REGMAP_IRQ_REG(BXTWC_CHGR1_IRQ, 3, 0x1f),
> -	REGMAP_IRQ_REG(BXTWC_CRIT_IRQ, 6, 0x03),
>  };
>  
> -static const struct regmap_irq bxtwc_regmap_irqs_tmu[] = {
> -	REGMAP_IRQ_REG(BXTWC_TMU_IRQ, 0, 0x06),
> +static const struct regmap_irq bxtwc_regmap_irqs_adc[] = {
> +	REGMAP_IRQ_REG(BXTWC_ADC_IRQ, 0, 0xff),
> +};
> +
> +static const struct regmap_irq bxtwc_regmap_irqs_chgr[] = {
> +	REGMAP_IRQ_REG(BXTWC_USBC_IRQ, 0, BIT(5)),
> +	REGMAP_IRQ_REG(BXTWC_CHGR0_IRQ, 0, 0x1f),
> +	REGMAP_IRQ_REG(BXTWC_CHGR1_IRQ, 1, 0x1f),
> +};
> +
> +static const struct regmap_irq bxtwc_regmap_irqs_crit[] = {
> +	REGMAP_IRQ_REG(BXTWC_CRIT_IRQ, 0, 0x03),
>  };
>  
>  static struct regmap_irq_chip bxtwc_regmap_irq_chip = {
> @@ -129,15 +146,6 @@ static struct regmap_irq_chip bxtwc_regmap_irq_chip = {
>  	.num_regs = 2,
>  };
>  
> -static struct regmap_irq_chip bxtwc_regmap_irq_chip_level2 = {
> -	.name = "bxtwc_irq_chip_level2",
> -	.status_base = BXTWC_BCUIRQ,
> -	.mask_base = BXTWC_MBCUIRQ,
> -	.irqs = bxtwc_regmap_irqs_level2,
> -	.num_irqs = ARRAY_SIZE(bxtwc_regmap_irqs_level2),
> -	.num_regs = 10,
> -};
> -
>  static struct regmap_irq_chip bxtwc_regmap_irq_chip_tmu = {
>  	.name = "bxtwc_irq_chip_tmu",
>  	.status_base = BXTWC_TMUIRQ,
> @@ -147,6 +155,42 @@ static struct regmap_irq_chip bxtwc_regmap_irq_chip_tmu = {
>  	.num_regs = 1,
>  };
>  
> +static struct regmap_irq_chip bxtwc_regmap_irq_chip_bcu = {
> +	.name = "bxtwc_irq_chip_bcu",
> +	.status_base = BXTWC_BCUIRQ,
> +	.mask_base = BXTWC_MBCUIRQ,
> +	.irqs = bxtwc_regmap_irqs_bcu,
> +	.num_irqs = ARRAY_SIZE(bxtwc_regmap_irqs_bcu),
> +	.num_regs = 1,
> +};
> +
> +static struct regmap_irq_chip bxtwc_regmap_irq_chip_adc = {
> +	.name = "bxtwc_irq_chip_adc",
> +	.status_base = BXTWC_ADCIRQ,
> +	.mask_base = BXTWC_MADCIRQ,
> +	.irqs = bxtwc_regmap_irqs_adc,
> +	.num_irqs = ARRAY_SIZE(bxtwc_regmap_irqs_adc),
> +	.num_regs = 1,
> +};
> +
> +static struct regmap_irq_chip bxtwc_regmap_irq_chip_chgr = {
> +	.name = "bxtwc_irq_chip_chgr",
> +	.status_base = BXTWC_CHGR0IRQ,
> +	.mask_base = BXTWC_MCHGR0IRQ,
> +	.irqs = bxtwc_regmap_irqs_chgr,
> +	.num_irqs = ARRAY_SIZE(bxtwc_regmap_irqs_chgr),
> +	.num_regs = 2,
> +};
> +
> +static struct regmap_irq_chip bxtwc_regmap_irq_chip_crit = {
> +	.name = "bxtwc_irq_chip_crit",
> +	.status_base = BXTWC_CRITIRQ,
> +	.mask_base = BXTWC_MCRITIRQ,
> +	.irqs = bxtwc_regmap_irqs_crit,
> +	.num_irqs = ARRAY_SIZE(bxtwc_regmap_irqs_crit),
> +	.num_regs = 1,
> +};
> +
>  static struct resource gpio_resources[] = {
>  	DEFINE_RES_IRQ_NAMED(BXTWC_GPIO_LVL1_IRQ, "GPIO"),
>  };
> @@ -358,6 +402,24 @@ static const struct regmap_config bxtwc_regmap_config = {
>  	.reg_read = regmap_ipc_byte_reg_read,
>  };
>  
> +static int bxtwc_add_chained_irq_chip(struct intel_soc_pmic *pmic,
> +				struct regmap_irq_chip_data *pdata,
> +				int pirq, int irq_flags,
> +				const struct regmap_irq_chip *chip,
> +				struct regmap_irq_chip_data **data)
> +{
> +	int irq;
> +
> +	irq = regmap_irq_get_virq(pdata, pirq);
> +	if (irq < 0) {
> +		dev_err(pmic->dev, "failed to get virtual interrupt:%d\n", irq);
> +		return irq;
> +	}
> +
> +	return devm_regmap_add_irq_chip(pmic->dev, pmic->regmap, irq, irq_flags,
> +					0, chip, data);
> +}
> +
>  static int bxtwc_probe(struct platform_device *pdev)
>  {
>  	int ret;
> @@ -409,21 +471,65 @@ static int bxtwc_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  
> -	ret = devm_regmap_add_irq_chip(&pdev->dev, pmic->regmap, pmic->irq,
> -				       IRQF_ONESHOT | IRQF_SHARED,
> -				       0, &bxtwc_regmap_irq_chip_level2,
> -				       &pmic->irq_chip_data_level2);
> +	ret = bxtwc_add_chained_irq_chip(pmic, pmic->irq_chip_data,
> +					 BXTWC_TMU_LVL1_IRQ,
> +					 IRQF_ONESHOT,
> +					 &bxtwc_regmap_irq_chip_tmu,
> +					 &pmic->irq_chip_data_tmu);
>  	if (ret) {
> -		dev_err(&pdev->dev, "Failed to add secondary IRQ chip\n");
> +		dev_err(&pdev->dev, "Failed to add TMU IRQ chip\n");
>  		return ret;
>  	}
>  
> -	ret = devm_regmap_add_irq_chip(&pdev->dev, pmic->regmap, pmic->irq,
> -				       IRQF_ONESHOT | IRQF_SHARED,
> -				       0, &bxtwc_regmap_irq_chip_tmu,
> -				       &pmic->irq_chip_data_tmu);
> +	/* Add chained IRQ handler for BCU IRQs */
> +	ret = bxtwc_add_chained_irq_chip(pmic, pmic->irq_chip_data,
> +					 BXTWC_BCU_LVL1_IRQ,
> +					 IRQF_ONESHOT,
> +					 &bxtwc_regmap_irq_chip_bcu,
> +					 &pmic->irq_chip_data_bcu);
> +
> +
>  	if (ret) {
> -		dev_err(&pdev->dev, "Failed to add TMU IRQ chip\n");
> +		dev_err(&pdev->dev, "Failed to add BUC IRQ chip\n");
> +		return ret;
> +	}
> +
> +	/* Add chained IRQ handler for ADC IRQs */
> +	ret = bxtwc_add_chained_irq_chip(pmic, pmic->irq_chip_data,
> +					 BXTWC_ADC_LVL1_IRQ,
> +					 IRQF_ONESHOT,
> +					 &bxtwc_regmap_irq_chip_adc,
> +					 &pmic->irq_chip_data_adc);
> +
> +
> +	if (ret) {
> +		dev_err(&pdev->dev, "Failed to add ADC IRQ chip\n");
> +		return ret;
> +	}
> +
> +	/* Add chained IRQ handler for CHGR IRQs */
> +	ret = bxtwc_add_chained_irq_chip(pmic, pmic->irq_chip_data,
> +					 BXTWC_CHGR_LVL1_IRQ,
> +					 IRQF_ONESHOT,
> +					 &bxtwc_regmap_irq_chip_chgr,
> +					 &pmic->irq_chip_data_chgr);
> +
> +
> +	if (ret) {
> +		dev_err(&pdev->dev, "Failed to add CHGR IRQ chip\n");
> +		return ret;
> +	}
> +
> +	/* Add chained IRQ handler for CRIT IRQs */
> +	ret = bxtwc_add_chained_irq_chip(pmic, pmic->irq_chip_data,
> +					 BXTWC_CRIT_LVL1_IRQ,
> +					 IRQF_ONESHOT,
> +					 &bxtwc_regmap_irq_chip_crit,
> +					 &pmic->irq_chip_data_crit);
> +
> +
> +	if (ret) {
> +		dev_err(&pdev->dev, "Failed to add CRIT IRQ chip\n");
>  		return ret;
>  	}
>  
> diff --git a/include/linux/mfd/intel_soc_pmic.h b/include/linux/mfd/intel_soc_pmic.h
> index 956caa0..5aacdb0 100644
> --- a/include/linux/mfd/intel_soc_pmic.h
> +++ b/include/linux/mfd/intel_soc_pmic.h
> @@ -25,8 +25,11 @@ struct intel_soc_pmic {
>  	int irq;
>  	struct regmap *regmap;
>  	struct regmap_irq_chip_data *irq_chip_data;
> -	struct regmap_irq_chip_data *irq_chip_data_level2;
>  	struct regmap_irq_chip_data *irq_chip_data_tmu;
> +	struct regmap_irq_chip_data *irq_chip_data_bcu;
> +	struct regmap_irq_chip_data *irq_chip_data_adc;
> +	struct regmap_irq_chip_data *irq_chip_data_chgr;
> +	struct regmap_irq_chip_data *irq_chip_data_crit;
>  	struct device *dev;
>  };
>  

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