linux-kernel - Re: [PATCH 3/3] power: supply: cpcap_battery: Read battery parameters from nvram

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Message-ID: <6d5e2890-a86b-1b9b-bb8f-474838d9bd86@gmail.com>
Date:   Mon, 5 Dec 2022 22:28:02 +0200
From:   Ivaylo Dimitrov <ivo.g.dimitrov.75@...il.com>
To:     sre@...nel.org
Cc:     linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
        tony@...mide.com, philipp@...s.xyz
Subject: Re: [PATCH 3/3] power: supply: cpcap_battery: Read battery parameters
 from nvram

ping

On 5.11.22 г. 13:25 ч., Ivaylo Dimitrov wrote:
> Formulas were taken from android blob
> 
> Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@...il.com>
> ---
>   drivers/power/supply/cpcap-battery.c | 88 ++++++++++++++++++++----------------
>   1 file changed, 48 insertions(+), 40 deletions(-)
> 
> diff --git a/drivers/power/supply/cpcap-battery.c b/drivers/power/supply/cpcap-battery.c
> index ca6ee2b..92aa66c 100644
> --- a/drivers/power/supply/cpcap-battery.c
> +++ b/drivers/power/supply/cpcap-battery.c
> @@ -74,9 +74,6 @@
>   
>   #define CPCAP_BATTERY_CC_SAMPLE_PERIOD_MS	250
>   
> -#define CPCAP_BATTERY_EB41_HW4X_ID 0x9E
> -#define CPCAP_BATTERY_BW8X_ID 0x98
> -
>   enum {
>   	CPCAP_BATTERY_IIO_BATTDET,
>   	CPCAP_BATTERY_IIO_VOLTAGE,
> @@ -388,22 +385,9 @@ static int cpcap_battery_cc_to_ua(struct cpcap_battery_ddata *ddata,
>    * kernel on droid 4, full is 4351000 and software initiates shutdown
>    * at 3078000. The device will die around 2743000.
>    */
> -static const struct cpcap_battery_config cpcap_battery_eb41_data = {
> -	.cd_factor = 0x3cc,
> -	.info.technology = POWER_SUPPLY_TECHNOLOGY_LION,
> -	.info.voltage_max_design = 4351000,
> -	.info.voltage_min_design = 3100000,
> -	.info.charge_full_design = 1740000,
> -	.bat.constant_charge_voltage_max_uv = 4200000,
> -};
> -
> -/* Values for the extended Droid Bionic battery bw8x. */
> -static const struct cpcap_battery_config cpcap_battery_bw8x_data = {
> +static struct cpcap_battery_config cpcap_battery_mot_data = {
>   	.cd_factor = 0x3cc,
>   	.info.technology = POWER_SUPPLY_TECHNOLOGY_LION,
> -	.info.voltage_max_design = 4200000,
> -	.info.voltage_min_design = 3200000,
> -	.info.charge_full_design = 2760000,
>   	.bat.constant_charge_voltage_max_uv = 4200000,
>   };
>   
> @@ -431,39 +415,63 @@ static int cpcap_battery_match_nvmem(struct device *dev, const void *data)
>   static void cpcap_battery_detect_battery_type(struct cpcap_battery_ddata *ddata)
>   {
>   	struct nvmem_device *nvmem;
> -	u8 battery_id = 0;
> +	char buf[24];
> +	u8 capacity;
> +	u8 mul_idx;
> +	u8 charge_voltage;
> +	u32 v;
> +	static const u32 multipliers[] = {20, 10, 10, 10, 10, 40, 10, 20, 40};
>   
>   	ddata->check_nvmem = false;
>   
>   	nvmem = nvmem_device_find(NULL, &cpcap_battery_match_nvmem);
>   	if (IS_ERR_OR_NULL(nvmem)) {
> -		ddata->check_nvmem = true;
>   		dev_info_once(ddata->dev, "Can not find battery nvmem device. Assuming generic lipo battery\n");
> -	} else {
> -		char buf[24];
> -
> -		if (nvmem_device_read(nvmem, 96, 4, buf) < 0 ||
> -		    strncmp(buf, "COPR", 4) != 0 ||
> -		    nvmem_device_read(nvmem, 104, 24, buf) < 0 ||
> -		    strncmp(buf, "MOTOROLA E.P CHARGE ONLY", 24) != 0 ||
> -		    nvmem_device_read(nvmem, 2, 1, &battery_id) < 0) {
> -			battery_id = 0;
> -			ddata->check_nvmem = true;
> -			dev_warn(ddata->dev, "Can not read battery nvmem device. Assuming generic lipo battery\n");
> -		}
> +		goto unknown;
> +	}
>   
> +	if (nvmem_device_read(nvmem, 96, 4, buf) < 0 ||
> +	    strncmp(buf, "COPR", 4) != 0 ||
> +	    nvmem_device_read(nvmem, 104, 24, buf) < 0 ||
> +	    strncmp(buf, "MOTOROLA E.P CHARGE ONLY", 24) != 0) {
> +		dev_warn(ddata->dev, "Unknown battery nvmem device. Assuming generic lipo battery\n");
> +		goto unknown;
>   	}
>   
> -	switch (battery_id) {
> -	case CPCAP_BATTERY_EB41_HW4X_ID:
> -		ddata->config = cpcap_battery_eb41_data;
> -		break;
> -	case CPCAP_BATTERY_BW8X_ID:
> -		ddata->config = cpcap_battery_bw8x_data;
> -		break;
> -	default:
> -		ddata->config = cpcap_battery_unkown_data;
> +	if (nvmem_device_read(nvmem, 49, 1, &mul_idx) < 0 ||
> +	    nvmem_device_read(nvmem, 34, 1, &capacity) < 0 ||
> +	    nvmem_device_read(nvmem, 65, 1, &charge_voltage) < 0) {
> +		dev_warn(ddata->dev, "Can not read battery nvmem device. Assuming generic lipo battery\n");
> +		goto unknown;
>   	}
> +
> +	/* design capacity */
> +	mul_idx -= 2;
> +
> +	if (mul_idx < ARRAY_SIZE(multipliers))
> +		v = multipliers[mul_idx];
> +	else
> +		v = 10;
> +
> +	cpcap_battery_mot_data.info.charge_full_design = 1000 * v * capacity;
> +
> +	/* design max voltage */
> +	v = 1000 * ((16702 * charge_voltage) / 1000 + 1260);
> +	cpcap_battery_mot_data.info.voltage_max_design = v;
> +
> +	/* design min voltage */
> +	if (v > 4200000)
> +		cpcap_battery_mot_data.info.voltage_min_design = 3100000;
> +	else
> +		cpcap_battery_mot_data.info.voltage_min_design = 3200000;
> +
> +	ddata->config = cpcap_battery_mot_data;
> +
> +	return;
> +
> +unknown:
> +	ddata->check_nvmem = true;
> +	ddata->config = cpcap_battery_unkown_data;
>   }
>   
>   /**
>