RE: [PATCH v3 11/12] mfd: bd9571mwv: Make the driver more generic

[Yoshihiro Shimoda]

Hi Lee,

Thank you for your review!

> From: Lee Jones, Sent: Thursday, December 17, 2020 12:35 AM
> 
> On Wed, 16 Dec 2020, Yoshihiro Shimoda wrote:
> 
> > From: Khiem Nguyen <khiem.nguyen.xt@xxxxxxxxxxx>
> >
> > Since the driver supports BD9571MWV PMIC only,
> > this patch makes the functions and data structure become more generic
> > so that it can support other PMIC variants as well.
> >
> > Signed-off-by: Khiem Nguyen <khiem.nguyen.xt@xxxxxxxxxxx>
> > [shimoda: rebase and refactor]
> 
> This is kind of expected.  Please just add Co-developed-by instead.

I got it.

> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> > ---
> >  drivers/mfd/bd9571mwv.c       | 95 +++++++++++++++++++++++++++----------------
> >  include/linux/mfd/bd9571mwv.h | 18 ++------
> >  2 files changed, 63 insertions(+), 50 deletions(-)
> >
> > diff --git a/drivers/mfd/bd9571mwv.c b/drivers/mfd/bd9571mwv.c
> > index 49e968e..ccf1a60 100644
> > --- a/drivers/mfd/bd9571mwv.c
> > +++ b/drivers/mfd/bd9571mwv.c
> > @@ -3,6 +3,7 @@
> >   * ROHM BD9571MWV-M MFD driver
> >   *
> >   * Copyright (C) 2017 Marek Vasut <marek.vasut+renesas@xxxxxxxxx>
> > + * Copyright (C) 2020 Renesas Electronics Corporation
> >   *
> >   * Based on the TPS65086 driver
> >   */
> > @@ -14,6 +15,19 @@
> >
> >  #include <linux/mfd/bd9571mwv.h>
> >
> > +/**
> 
> This is wrong.  Please do not abuse kernel-doc formatting.

Oops. I'll use just "/*" here.

> > + * struct bd957x_data - internal data for the bd957x driverbd957x_data
> > + *
> > + * Internal data to distinguish bd957x variants
> > + */
> > +struct bd957x_data {
> 
> Call this bd957x_ddata please.
> 
> ddata == driver data.

I got it.

> > +	char *part_name;
> 
> What is this used for besides a print?  Those kinds of log messages
> are usually frowned upon anyway.  Probably best to just remove the
> print, along with the variable.

I got it. I'll remove the print.

> > +	const struct regmap_config *regmap_config;
> > +	const struct regmap_irq_chip *irq_chip;
> > +	const struct mfd_cell *cells;
> > +	int num_cells;
> > +};
> > +
> >  static const struct mfd_cell bd9571mwv_cells[] = {
> >  	{ .name = "bd9571mwv-regulator", },
> >  	{ .name = "bd9571mwv-gpio", },
> > @@ -102,13 +116,21 @@ static struct regmap_irq_chip bd9571mwv_irq_chip = {
> >  	.num_irqs	= ARRAY_SIZE(bd9571mwv_irqs),
> >  };
> >
> > -static int bd9571mwv_identify(struct bd9571mwv *bd)
> > +static const struct bd957x_data bd9571mwv_data = {
> > +	.part_name = BD9571MWV_PART_NAME,
> > +	.regmap_config = &bd9571mwv_regmap_config,
> > +	.irq_chip = &bd9571mwv_irq_chip,
> > +	.cells = bd9571mwv_cells,
> > +	.num_cells = ARRAY_SIZE(bd9571mwv_cells),
> > +};
> > +
> > +static int bd9571mwv_identify(struct device *dev, struct regmap *regmap,
> 
> I guess this function name also needs to change?
> 
> And all other occurences of bd9571mwv?

Hmm, "bd957x" prefix is already used on a regulator driver (bd9576-regulator.c)
so that I'm thinking keep "bd9571mwv" is better to avoid confusing.
But, this is not a strong opinion so that if you prefer "bd957x" here,
I'll rename.

> > +			      const char *part_name)
> >  {
> > -	struct device *dev = bd->dev;
> >  	unsigned int value;
> >  	int ret;
> >
> > -	ret = regmap_read(bd->regmap, BD9571MWV_VENDOR_CODE, &value);
> > +	ret = regmap_read(regmap, BD9571MWV_VENDOR_CODE, &value);
> >  	if (ret) {
> >  		dev_err(dev, "Failed to read vendor code register (ret=%i)\n",
> >  			ret);
> > @@ -121,27 +143,20 @@ static int bd9571mwv_identify(struct bd9571mwv *bd)
> >  		return -EINVAL;
> >  	}
> >
> > -	ret = regmap_read(bd->regmap, BD9571MWV_PRODUCT_CODE, &value);
> > +	ret = regmap_read(regmap, BD9571MWV_PRODUCT_CODE, &value);
> >  	if (ret) {
> >  		dev_err(dev, "Failed to read product code register (ret=%i)\n",
> >  			ret);
> >  		return ret;
> >  	}
> > -
> > -	if (value != BD9571MWV_PRODUCT_CODE_VAL) {
> > -		dev_err(dev, "Invalid product code ID %02x (expected %02x)\n",
> > -			value, BD9571MWV_PRODUCT_CODE_VAL);
> > -		return -EINVAL;
> > -	}
> > -
> > -	ret = regmap_read(bd->regmap, BD9571MWV_PRODUCT_REVISION, &value);
> > +	ret = regmap_read(regmap, BD9571MWV_PRODUCT_REVISION, &value);
> >  	if (ret) {
> >  		dev_err(dev, "Failed to read revision register (ret=%i)\n",
> >  			ret);
> >  		return ret;
> >  	}
> >
> > -	dev_info(dev, "Device: BD9571MWV rev. %d\n", value & 0xff);
> > +	dev_info(dev, "Device: %s rev. %d\n", part_name, value & 0xff);
> >
> >  	return 0;
> >  }
> > @@ -149,38 +164,48 @@ static int bd9571mwv_identify(struct bd9571mwv *bd)
> >  static int bd9571mwv_probe(struct i2c_client *client,
> >  			  const struct i2c_device_id *ids)
> >  {
> > -	struct bd9571mwv *bd;
> > -	int ret;
> > -
> > -	bd = devm_kzalloc(&client->dev, sizeof(*bd), GFP_KERNEL);
> > -	if (!bd)
> > -		return -ENOMEM;
> > -
> > -	i2c_set_clientdata(client, bd);
> > -	bd->dev = &client->dev;
> > -	bd->irq = client->irq;
> > +	const struct bd957x_data *data;
> 
> ddata

I'll change it.

> > +	struct device *dev = &client->dev;
> > +	struct regmap *regmap;
> > +	struct regmap_irq_chip_data *irq_data;
> > +	int ret, irq = client->irq;
> > +
> > +	/* Read the PMIC product code */
> > +	ret = i2c_smbus_read_byte_data(client, BD9571MWV_PRODUCT_CODE);
> > +	if (ret < 0) {
> > +		dev_err(dev, "failed reading at 0x%02x\n",
> > +			BD9571MWV_PRODUCT_CODE);
> 
> "Failed to read product code" is more user friendly.

I got it. Thank you for your suggestion.

> > +		return ret;
> > +	}
> > +	switch (ret) {
> > +	case BD9571MWV_PRODUCT_CODE_VAL:
> 
> Suggest:
> 
> s/BD9571MWV_PRODUCT_CODE/BD9571MWV_PRODUCT_CODE_CMD/
>   then
> s/BD9571MWV_PRODUCT_CODE_VAL/BD9571MWV_PRODUCT_CODE/

Hmm, if we use "BD9571MWV_PRODUCT_CODE_CMD", this causes
inconsistence other registers' definitions. So, perhaps,
BD9571MWV_PRODUCT_CODE_BD9571MWV (and BD9571MWV_PRODUCT_CODE_BD9574MWF
in the patch 12/12) instead of "_VAL" are better.

> > +		data = &bd9571mwv_data;
> > +		break;
> > +	default:
> > +		dev_err(dev, "Unsupported device 0x%x\n", ret);
> > +		return -ENOENT;
> 
> ENOENT == "No such file or directory"
> 
> I think you mean -ENODEV.

Oops. I'll fix it.

> > +	}
> >
> > -	bd->regmap = devm_regmap_init_i2c(client, &bd9571mwv_regmap_config);
> > -	if (IS_ERR(bd->regmap)) {
> > -		dev_err(bd->dev, "Failed to initialize register map\n");
> > -		return PTR_ERR(bd->regmap);
> > +	regmap = devm_regmap_init_i2c(client, data->regmap_config);
> > +	if (IS_ERR(regmap)) {
> > +		dev_err(dev, "Failed to initialize register map\n");
> > +		return PTR_ERR(regmap);
> >  	}
> >
> > -	ret = bd9571mwv_identify(bd);
> > +	ret = bd9571mwv_identify(dev, regmap, data->part_name);
> 
> Just pass ddata, then you'll have 'dev' and 'regmap'.

Now "bd9571mwv_ddata" is const and doesn't have 'dev' and 'regmap'.
Does this means I should not use const and add device and regmap into
struct bd957x_ddata?

> I'd remove 'part_name' completely.

I got it.

Best regards,
Yoshihiro Shimoda