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

Thomas Antoine via B4 Relay
2024-12-02T13:08:21Z

From: Thomas Antoine <t.antoine@uclouvain.be>

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@uclouvain.be>
---
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>

#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,
+};
+
/*
* Model Gauge M5 Algorithm output register
* Volatile data (must not be cached)
@@ -369,6 +387,8 @@ static int max1720x_battery_get_property(struct power_supply *psy,
val->strval = max17201_model;
else if (reg_val == MAX172XX_DEV_NAME_TYPE_MAX17205)
val->strval = max17205_model;
+ else if (reg_val == MAX172XX_DEV_NAME_TYPE_MAX77759)
+ val->strval = max77759_model;
else
return -ENODEV;
break;
@@ -416,7 +436,6 @@ static int max1720x_probe_nvmem(struct i2c_client *client,
.priv = info,
};
struct nvmem_device *nvmem;
- unsigned int val;
int ret;

info->ancillary = i2c_new_ancillary_device(client, "nvmem", 0xb);
@@ -438,6 +457,27 @@ static int max1720x_probe_nvmem(struct i2c_client *client,
return PTR_ERR(info->regmap_nv);
}

+ nvmem = devm_nvmem_register(dev, &nvmem_config);
+ if (IS_ERR(nvmem)) {
+ dev_err(dev, "Could not register nvmem!");
+ return PTR_ERR(nvmem);
+ }
+
+ return 0;
+}
+
+static int max1720x_get_rsense(struct device *dev,
+ struct max1720x_device_info *info,
+ const struct chip_data *data)
+{
+ unsigned int val;
+ int ret;
+
+ if (!data->has_nvmem) {
+ info->rsense = data->default_nrsense;
+ return 0;
+ }
+
ret = regmap_read(info->regmap_nv, MAX1720X_NRSENSE, &val);
if (ret < 0) {
dev_err(dev, "Failed to read sense resistor value\n");
@@ -446,14 +486,9 @@ static int max1720x_probe_nvmem(struct i2c_client *client,

info->rsense = val;
if (!info->rsense) {
- dev_warn(dev, "RSense not calibrated, set 10 mOhms!\n");
- info->rsense = 1000; /* in regs in 10^-5 */
- }
-
- nvmem = devm_nvmem_register(dev, &nvmem_config);
- if (IS_ERR(nvmem)) {
- dev_err(dev, "Could not register nvmem!");
- return PTR_ERR(nvmem);
+ dev_warn(dev, "RSense not calibrated, set %d mOhms!\n",
+ data->default_nrsense/100);
+ info->rsense = data->default_nrsense;
}

return 0;
@@ -474,6 +509,7 @@ static int max1720x_probe(struct i2c_client *client)
struct device *dev = &client->dev;
struct max1720x_device_info *info;
struct power_supply *bat;
+ const struct chip_data *data;
int ret;

info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
@@ -488,9 +524,19 @@ static int max1720x_probe(struct i2c_client *client)
return dev_err_probe(dev, PTR_ERR(info->regmap),
"regmap initialization failed\n");

- ret = max1720x_probe_nvmem(client, info);
+ data = device_get_match_data(dev);
+ if (!data)
+ return dev_err_probe(dev, ret, "Failed to get chip data\n");
+
+ if (data->has_nvmem) {
+ ret = max1720x_probe_nvmem(client, info);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to probe nvmem\n");
+ }
+
+ ret = max1720x_get_rsense(dev, info, data);
if (ret)
- return dev_err_probe(dev, ret, "Failed to probe nvmem\n");
+ return dev_err_probe(dev, ret, "Failed to get RSense");

bat = devm_power_supply_register(dev, &max1720x_bat_desc, &psy_cfg);
if (IS_ERR(bat))
@@ -501,7 +547,8 @@ static int max1720x_probe(struct i2c_client *client)
}

static const struct of_device_id max1720x_of_match[] = {
- { .compatible = "maxim,max17201" },
+ { .compatible = "maxim,max17201", .data = (void *) &max1720x_data },
+ { .compatible = "maxim,max77759-fg", .data = (void *) &max77759_data},
{}
};
MODULE_DEVICE_TABLE(of, max1720x_of_match);

--
2.47.1