linux-kernel - Re: [PATCH v3 2/3] extcon: sm5502: Refactor driver to use chip-specific struct

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Date:   Wed, 2 Jun 2021 17:20:57 +0200
From:   Stephan Gerhold <stephan@...hold.net>
To:     Chanwoo Choi <cwchoi00@...il.com>
Cc:     Chanwoo Choi <cw00.choi@...sung.com>,
        MyungJoo Ham <myungjoo.ham@...sung.com>,
        Rob Herring <robh+dt@...nel.org>, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, Nikita Travkin <nikita@...n.ru>,
        ~postmarketos/upstreaming@...ts.sr.ht
Subject: Re: [PATCH v3 2/3] extcon: sm5502: Refactor driver to use
 chip-specific struct

On Thu, Jun 03, 2021 at 12:13:18AM +0900, Chanwoo Choi wrote:
> On 21. 6. 2. 오전 5:00, Stephan Gerhold wrote:
> > Prepare for supporting SM5504 in the extcon-sm5502 driver by replacing
> > enum sm5504_types with a struct sm5504_type that stores the chip-specific
> > definitions. This struct can then be defined separately for SM5504
> > without having to add if (type == TYPE_SM5504) everywhere in the code.
> > 
> > Signed-off-by: Stephan Gerhold <stephan@...hold.net>
> > ---
> > Changes in v3: New patch to simplify diff on next patch
> > ---
> >   drivers/extcon/extcon-sm5502.c | 64 +++++++++++++++++++++-------------
> >   drivers/extcon/extcon-sm5502.h |  4 ---
> >   2 files changed, 40 insertions(+), 28 deletions(-)
> > 
> > diff --git a/drivers/extcon/extcon-sm5502.c b/drivers/extcon/extcon-sm5502.c
> > index 9f40bb9f1f81..951f6ca4c479 100644
> > --- a/drivers/extcon/extcon-sm5502.c
> > +++ b/drivers/extcon/extcon-sm5502.c
> > @@ -40,17 +40,13 @@ struct sm5502_muic_info {
> >   	struct i2c_client *i2c;
> >   	struct regmap *regmap;
> > +	const struct sm5502_type *type;
> >   	struct regmap_irq_chip_data *irq_data;
> > -	struct muic_irq *muic_irqs;
> > -	unsigned int num_muic_irqs;
> >   	int irq;
> >   	bool irq_attach;
> >   	bool irq_detach;
> >   	struct work_struct irq_work;
> > -	struct reg_data *reg_data;
> > -	unsigned int num_reg_data;
> > -
> >   	struct mutex mutex;
> >   	/*
> > @@ -62,6 +58,17 @@ struct sm5502_muic_info {
> >   	struct delayed_work wq_detcable;
> >   };
> > +struct sm5502_type {
> > +	struct muic_irq *muic_irqs;
> > +	unsigned int num_muic_irqs;
> > +	const struct regmap_irq_chip *irq_chip;
> > +
> > +	struct reg_data *reg_data;
> > +	unsigned int num_reg_data;
> > +
> > +	int (*parse_irq)(struct sm5502_muic_info *info, int irq_type);
> > +};
> > +
> >   /* Default value of SM5502 register to bring up MUIC device. */
> >   static struct reg_data sm5502_reg_data[] = {
> >   	{
> > @@ -502,11 +509,11 @@ static irqreturn_t sm5502_muic_irq_handler(int irq, void *data)
> >   	struct sm5502_muic_info *info = data;
> >   	int i, irq_type = -1, ret;
> > -	for (i = 0; i < info->num_muic_irqs; i++)
> > -		if (irq == info->muic_irqs[i].virq)
> > -			irq_type = info->muic_irqs[i].irq;
> > +	for (i = 0; i < info->type->num_muic_irqs; i++)
> > +		if (irq == info->type->muic_irqs[i].virq)
> > +			irq_type = info->type->muic_irqs[i].irq;
> > -	ret = sm5502_parse_irq(info, irq_type);
> > +	ret = info->type->parse_irq(info, irq_type);
> 
> Looks good to me. But there is only one comment.
> Need to check the 'parse_irq' as following:
> 
> If you agree this suggestion, I'll apply with following changes by myself:
> 
> 	if (!info->type->parse_irq) {
> 		dev_err(info->dev, "failed to handle irq due to parse_irq\n",
> 		return IRQ_NONE;
> 	}
> 
> 

This condition should be impossible, since .parse_irq is set for both
SM5502 and SM5504:

static const struct sm5502_type sm5502_data = {
	/* ... */
	.parse_irq = sm5502_parse_irq,
};

static const struct sm5502_type sm5504_data = {
	/* ... */
	.parse_irq = sm5504_parse_irq,
};

Which failure case are you trying to handle with that if statement?

Thanks!
Stephan