Re: [PATCH 3/4] iio: accel: mc3230: add mc3510c support

[Markuss Broks <markuss.broks@xxxxxxxxx>]

On 1/11/25 10:11 PM, Vasiliy Doylov via B4 Relay wrote:
> From: Vasiliy Doylov <nekodevelopper@xxxxxxxxx>
>
> This commit integrates support for the mc3510c into the mc3230 driver.
>
> Tested on Huawei MediaPad T3 10 (huawei-agassi)
>
> Signed-off-by: Vasiliy Doylov <nekodevelopper@xxxxxxxxx>
> ---
>   drivers/iio/accel/mc3230.c | 55 ++++++++++++++++++++++++++++++++++++----------
>   1 file changed, 44 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/iio/accel/mc3230.c b/drivers/iio/accel/mc3230.c
> index 3cad6f2d7a2a79df38f90e5656763f6ed019a920..ebbb96c658d87a83007c7c3c7212ce9ebf039963 100644
> --- a/drivers/iio/accel/mc3230.c
> +++ b/drivers/iio/accel/mc3230.c
> @@ -22,20 +22,41 @@
>   #define MC3230_MODE_OPCON_STANDBY	0x03
>   
>   #define MC3230_REG_CHIP_ID		0x18
> -#define MC3230_CHIP_ID			0x01
> -
>   #define MC3230_REG_PRODUCT_CODE		0x3b
> -#define MC3230_PRODUCT_CODE		0x19
>   
>   /*
>    * The accelerometer has one measurement range:
>    *
>    * -1.5g - +1.5g (8-bit, signed)
>    *
> - * scale = (1.5 + 1.5) * 9.81 / (2^8 - 1)	= 0.115411765
>    */
>   
> -static const int mc3230_nscale = 115411765;
> +enum mc3xxx_chips {
> +	MC3230,
> +	MC3510C,
> +};
> +
> +struct mc3xxx_chip_info {
> +	const char *name;
> +	const u8 chip_id;
> +	const u8 product_code;
> +	const int scale;
> +};
The struct members are usually ordered alphabetically. Also, const 
specifiers for u8s and int are redundant, you will only want it for the 
pointer, usually.
> +
> +static struct mc3xxx_chip_info mc3xxx_chip_info_tbl[] = {
> +	[MC3230] = {
> +		.name = "mc3230",
> +		.chip_id = 0x01,
> +		.product_code = 0x19,
> +		.scale = 115411765, // (1.5 + 1.5) * 9.81 / (2^8 - 1) = 0.115411765
/* */ style comments are preferred. Also, it should be above the .scale 
to not make the line so long (even if the line length requirement is met).
> +	},
> +	[MC3510C] = {
> +		.name = "mc3510c",
> +		.chip_id = 0x23,
> +		.product_code = 0x10,
> +		.scale = 625000000, // Was obtained empirically
Same here.
> +	},
> +};
>   
>   #define MC3230_CHANNEL(reg, axis) {	\
>   	.type = IIO_ACCEL,	\
> @@ -50,6 +71,7 @@ static const int mc3230_nscale = 115411765;
>   struct mc3230_data {
>   	struct i2c_client *client;
>   	struct iio_mount_matrix orientation;
> +	const struct mc3xxx_chip_info *chip_info;
Same here, order alphabetically.
>   };
>   
>   static const struct iio_mount_matrix *
> @@ -111,7 +133,7 @@ static int mc3230_read_raw(struct iio_dev *indio_dev,
>   		return IIO_VAL_INT;
>   	case IIO_CHAN_INFO_SCALE:
>   		*val = 0;
> -		*val2 = mc3230_nscale;
> +		*val2 = data->chip_info->scale;
>   		return IIO_VAL_INT_PLUS_NANO;
>   	default:
>   		return -EINVAL;
> @@ -127,15 +149,23 @@ static int mc3230_probe(struct i2c_client *client)
>   	int ret;
>   	struct iio_dev *indio_dev;
>   	struct mc3230_data *data;
> +	const struct mc3xxx_chip_info *chip_info;
>   
> +	chip_info = i2c_get_match_data(client);
>   	/* First check chip-id and product-id */
>   	ret = i2c_smbus_read_byte_data(client, MC3230_REG_CHIP_ID);
> -	if (ret != MC3230_CHIP_ID)
> +	if (ret != chip_info->chip_id) {
> +		dev_err(&client->dev,
> +		"chip id check fail: 0x%x != 0x%x !\n", ret, chip_info->chip_id);
>   		return (ret < 0) ? ret : -ENODEV;
> +	}
>   
>   	ret = i2c_smbus_read_byte_data(client, MC3230_REG_PRODUCT_CODE);
> -	if (ret != MC3230_PRODUCT_CODE)
> +	if (ret != chip_info->product_code) {
> +		dev_err(&client->dev,
> +		"product code check fail: 0x%x != 0x%x !\n", ret, chip_info->product_code);
>   		return (ret < 0) ? ret : -ENODEV;
> +	}
>   
>   	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
>   	if (!indio_dev) {
> @@ -145,10 +175,11 @@ static int mc3230_probe(struct i2c_client *client)
>   
>   	data = iio_priv(indio_dev);
>   	data->client = client;
> +	data->chip_info = chip_info;
>   	i2c_set_clientdata(client, indio_dev);
>   
>   	indio_dev->info = &mc3230_info;
> -	indio_dev->name = "mc3230";
> +	indio_dev->name = chip_info->name;
>   	indio_dev->modes = INDIO_DIRECT_MODE;
>   	indio_dev->channels = mc3230_channels;
>   	indio_dev->num_channels = ARRAY_SIZE(mc3230_channels);
> @@ -200,13 +231,15 @@ static int mc3230_resume(struct device *dev)
>   static DEFINE_SIMPLE_DEV_PM_OPS(mc3230_pm_ops, mc3230_suspend, mc3230_resume);
>   
>   static const struct i2c_device_id mc3230_i2c_id[] = {
> -	{ "mc3230" },
> +	{ "mc3230", (kernel_ulong_t)&mc3xxx_chip_info_tbl[MC3230] },
> +	{ "mc3510c", (kernel_ulong_t)&mc3xxx_chip_info_tbl[MC3510C] },
>   	{}
>   };
>   MODULE_DEVICE_TABLE(i2c, mc3230_i2c_id);
>   
>   static const struct of_device_id mc3230_of_match[] = {
> -	{ .compatible = "mcube,mc3230" },
> +	{ .compatible = "mcube,mc3230", &mc3xxx_chip_info_tbl[MC3230] },
> +	{ .compatible = "mcube,mc3510c", &mc3xxx_chip_info_tbl[MC3510C] },
>   	{ },
>   };
>   MODULE_DEVICE_TABLE(of, mc3230_of_match);