Re: [PATCH 1/4] power: supply: add support for max77759 fuel gauge

[Dimitri Fedrau]

Hi Antoine,

Am Mon, Dec 02, 2024 at 02:07:15PM +0100 schrieb Thomas Antoine via B4 Relay:
> From: Thomas Antoine <t.antoine@xxxxxxxxxxxx>
> 
> The Maxim max77759 fuel gauge has the same interface as the Maxim max1720x
> except for the non-volatile memory slave address which is not available.
> No slave is available at address 0xb of the i2c bus, which is coherent
> with the following driver from google: line 5836 disables non-volatile
> memory for m5 gauge.
> 
> Link: https://android.googlesource.com/kernel/google-modules/bms/+/1a68c36bef474573cc8629cc1d121eb6a81ab68c/max1720x_battery.c
> 
> Add support for the max77759 by allowing to use the non-volatile
> memory or not based on the chip. Value for RSense comes from the following
> stock devicetree:
> 
> Link: https://android.googlesource.com/kernel/devices/google/gs101/+/33eca36d43da6c2b6a546806eb3e7411bbe6d60d/dts/gs101-raviole-battery.dtsi
> 
> Signed-off-by: Thomas Antoine <t.antoine@xxxxxxxxxxxx>
> ---
>  drivers/power/supply/max1720x_battery.c | 71 +++++++++++++++++++++++++++------
>  1 file changed, 59 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/power/supply/max1720x_battery.c b/drivers/power/supply/max1720x_battery.c
> index 33105419e2427bb37963bda9948b647c239f8faa..faf336938dd4306dd2ceeb0a84b90ca80ad41a9f 100644
> --- a/drivers/power/supply/max1720x_battery.c
> +++ b/drivers/power/supply/max1720x_battery.c
> @@ -13,6 +13,7 @@
>  #include <linux/nvmem-provider.h>
>  #include <linux/power_supply.h>
>  #include <linux/regmap.h>
> +#include <linux/types.h>
>  
No need to include it, it is done by <linux/i2.c> which includes
<linux/device.h> which includes <linux/types.h>
>  #include <linux/unaligned.h>
>  
> @@ -39,6 +40,7 @@
>  #define MAX172XX_DEV_NAME_TYPE_MASK	GENMASK(3, 0)
>  #define MAX172XX_DEV_NAME_TYPE_MAX17201	BIT(0)
>  #define MAX172XX_DEV_NAME_TYPE_MAX17205	(BIT(0) | BIT(2))
> +#define MAX172XX_DEV_NAME_TYPE_MAX77759	0
>  #define MAX172XX_QR_TABLE10		0x22
>  #define MAX172XX_BATT			0xDA	/* Battery voltage */
>  #define MAX172XX_ATAVCAP		0xDF
> @@ -46,6 +48,7 @@
>  static const char *const max1720x_manufacturer = "Maxim Integrated";
>  static const char *const max17201_model = "MAX17201";
>  static const char *const max17205_model = "MAX17205";
> +static const char *const max77759_model = "MAX77759";
>  
>  struct max1720x_device_info {
>  	struct regmap *regmap;
> @@ -54,6 +57,21 @@ struct max1720x_device_info {
>  	int rsense;
>  };
>  
> +struct chip_data {
> +	u16 default_nrsense; /* in regs in 10^-5 */
> +	u8 has_nvmem;
> +};
> +
> +static const struct chip_data max1720x_data  = {
> +	.default_nrsense = 1000,
> +	.has_nvmem = 1,
> +};
> +
> +static const struct chip_data max77759_data = {
> +	.default_nrsense = 500,
> +	.has_nvmem = 0,
> +};
> +
You can get rid of chip_data by reading rsense from DT and moving
has_nvmem to max1720x_device_info. By doing so you don't have to rely on
default values. Either it is specified by DT or by rsense value in
nvmem.

Best regards,
Dimitri Fedrau