[PATCH v5 4/7] power: supply: max17040: Support compatible devices

From: Iskren Chernev
Date: Tue Sep 22 2020 - 07:48:29 EST


The max17040 fuel gauge is part of a family of 8 chips that have very
similar mode of operations and registers.

This change adds:
- compatible strings for all supported devices and handling for the
minor differences between them;
- handling for devices reporting double capacity via maxim,double-soc;

The datasheets of the supported devices are linked [0] [1] [2] [3].

[0] https://datasheets.maximintegrated.com/en/ds/MAX17040-MAX17041.pdf
[1] https://datasheets.maximintegrated.com/en/ds/MAX17043-MAX17044.pdf
[2] https://datasheets.maximintegrated.com/en/ds/MAX17048-MAX17049.pdf
[3] https://datasheets.maximintegrated.com/en/ds/MAX17058-MAX17059.pdf

Signed-off-by: Iskren Chernev <iskren.chernev@xxxxxxxxx>
Tested-by: Jonathan Bakker <xc-racer2@xxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
---
drivers/power/supply/Kconfig | 10 +-
drivers/power/supply/max17040_battery.c | 155 +++++++++++++++++++++---
2 files changed, 143 insertions(+), 22 deletions(-)

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 47a4e1d363fc3..de9e0fa9a861b 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -369,9 +369,13 @@ config BATTERY_MAX17040
depends on I2C
select REGMAP_I2C
help
- MAX17040 is fuel-gauge systems for lithium-ion (Li+) batteries
- in handheld and portable equipment. The MAX17040 is configured
- to operate with a single lithium cell
+ Maxim models with ModelGauge are fuel-gauge systems for lithium-ion
+ (Li+) batteries in handheld and portable equipment, including
+ max17040, max17041, max17043, max17044, max17048, max17049, max17058,
+ max17059. It is also included in some batteries like max77836.
+
+ Driver supports reporting SOC (State of Charge, i.e capacity),
+ voltage and configurable low-SOC wakeup interrupt.

config BATTERY_MAX17042
tristate "Maxim MAX17042/17047/17050/8997/8966 Fuel Gauge"
diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c
index fae4217960761..4bcec86d92098 100644
--- a/drivers/power/supply/max17040_battery.c
+++ b/drivers/power/supply/max17040_battery.c
@@ -15,6 +15,7 @@
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/power_supply.h>
+#include <linux/of_device.h>
#include <linux/max17040_battery.h>
#include <linux/regmap.h>
#include <linux/slab.h>
@@ -33,12 +34,92 @@
#define MAX17040_ATHD_MASK 0x3f
#define MAX17040_ATHD_DEFAULT_POWER_UP 4

+enum chip_id {
+ ID_MAX17040,
+ ID_MAX17041,
+ ID_MAX17043,
+ ID_MAX17044,
+ ID_MAX17048,
+ ID_MAX17049,
+ ID_MAX17058,
+ ID_MAX17059,
+};
+
+/* values that differ by chip_id */
+struct chip_data {
+ u16 reset_val;
+ u16 vcell_shift;
+ u16 vcell_mul;
+ u16 vcell_div;
+ u8 has_low_soc_alert;
+};
+
+static struct chip_data max17040_family[] = {
+ [ID_MAX17040] = {
+ .reset_val = 0x0054,
+ .vcell_shift = 4,
+ .vcell_mul = 1250,
+ .vcell_div = 1,
+ .has_low_soc_alert = 0,
+ },
+ [ID_MAX17041] = {
+ .reset_val = 0x0054,
+ .vcell_shift = 4,
+ .vcell_mul = 2500,
+ .vcell_div = 1,
+ .has_low_soc_alert = 0,
+ },
+ [ID_MAX17043] = {
+ .reset_val = 0x0054,
+ .vcell_shift = 4,
+ .vcell_mul = 1250,
+ .vcell_div = 1,
+ .has_low_soc_alert = 1,
+ },
+ [ID_MAX17044] = {
+ .reset_val = 0x0054,
+ .vcell_shift = 4,
+ .vcell_mul = 2500,
+ .vcell_div = 1,
+ .has_low_soc_alert = 1,
+ },
+ [ID_MAX17048] = {
+ .reset_val = 0x5400,
+ .vcell_shift = 0,
+ .vcell_mul = 625,
+ .vcell_div = 8,
+ .has_low_soc_alert = 1,
+ },
+ [ID_MAX17049] = {
+ .reset_val = 0x5400,
+ .vcell_shift = 0,
+ .vcell_mul = 625,
+ .vcell_div = 4,
+ .has_low_soc_alert = 1,
+ },
+ [ID_MAX17058] = {
+ .reset_val = 0x5400,
+ .vcell_shift = 0,
+ .vcell_mul = 625,
+ .vcell_div = 8,
+ .has_low_soc_alert = 1,
+ },
+ [ID_MAX17059] = {
+ .reset_val = 0x5400,
+ .vcell_shift = 0,
+ .vcell_mul = 625,
+ .vcell_div = 4,
+ .has_low_soc_alert = 1,
+ },
+};
+
struct max17040_chip {
struct i2c_client *client;
struct regmap *regmap;
struct delayed_work work;
struct power_supply *battery;
struct max17040_platform_data *pdata;
+ struct chip_data data;

/* battery capacity */
int soc;
@@ -46,27 +127,37 @@ struct max17040_chip {
int status;
/* Low alert threshold from 32% to 1% of the State of Charge */
u32 low_soc_alert;
+ /* some devices return twice the capacity */
+ bool quirk_double_soc;
};

static int max17040_reset(struct max17040_chip *chip)
{
- return regmap_write(chip->regmap, MAX17040_CMD, 0x0054);
+ return regmap_write(chip->regmap, MAX17040_CMD, chip->data.reset_val);
}

static int max17040_set_low_soc_alert(struct max17040_chip *chip, u32 level)
{
- level = 32 - level;
+ level = 32 - level * (chip->quirk_double_soc ? 2 : 1);
return regmap_update_bits(chip->regmap, MAX17040_CONFIG,
MAX17040_ATHD_MASK, level);
}

+static int max17040_raw_vcell_to_uvolts(struct max17040_chip *chip, u16 vcell)
+{
+ struct chip_data *d = &chip->data;
+
+ return (vcell >> d->vcell_shift) * d->vcell_mul / d->vcell_div;
+}
+
+
static int max17040_get_vcell(struct max17040_chip *chip)
{
u32 vcell;

regmap_read(chip->regmap, MAX17040_VCELL, &vcell);

- return (vcell >> 4) * 1250;
+ return max17040_raw_vcell_to_uvolts(chip, vcell);
}

static int max17040_get_soc(struct max17040_chip *chip)
@@ -75,7 +166,7 @@ static int max17040_get_soc(struct max17040_chip *chip)

regmap_read(chip->regmap, MAX17040_SOC, &soc);

- return soc >> 8;
+ return soc >> (chip->quirk_double_soc ? 9 : 8);
}

static int max17040_get_version(struct max17040_chip *chip)
@@ -116,12 +207,16 @@ static int max17040_get_of_data(struct max17040_chip *chip)
{
struct device *dev = &chip->client->dev;

+ chip->quirk_double_soc = device_property_read_bool(dev,
+ "maxim,double-soc");
+
chip->low_soc_alert = MAX17040_ATHD_DEFAULT_POWER_UP;
device_property_read_u32(dev,
"maxim,alert-low-soc-level",
&chip->low_soc_alert);

- if (chip->low_soc_alert <= 0 || chip->low_soc_alert >= 33) {
+ if (chip->low_soc_alert <= 0 ||
+ chip->low_soc_alert > (chip->quirk_double_soc ? 16 : 32)) {
dev_err(dev, "maxim,alert-low-soc-level out of bounds\n");
return -EINVAL;
}
@@ -219,8 +314,9 @@ static int max17040_set_property(struct power_supply *psy,

switch (psp) {
case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
- /* alert threshold can be programmed from 1% up to 32% */
- if ((val->intval < 1) || (val->intval > 32)) {
+ /* alert threshold can be programmed from 1% up to 16/32% */
+ if ((val->intval < 1) ||
+ (val->intval > (chip->quirk_double_soc ? 16 : 32))) {
ret = -EINVAL;
break;
}
@@ -293,6 +389,7 @@ static int max17040_probe(struct i2c_client *client,
struct i2c_adapter *adapter = client->adapter;
struct power_supply_config psy_cfg = {};
struct max17040_chip *chip;
+ enum chip_id chip_id;
int ret;

if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
@@ -305,9 +402,15 @@ static int max17040_probe(struct i2c_client *client,
chip->client = client;
chip->regmap = devm_regmap_init_i2c(client, &max17040_regmap);
chip->pdata = client->dev.platform_data;
- ret = max17040_get_of_data(chip);
- if (ret)
- return ret;
+ chip_id = (enum chip_id) id->driver_data;
+ if (client->dev.of_node) {
+ ret = max17040_get_of_data(chip);
+ if (ret)
+ return ret;
+ chip_id = (enum chip_id) (uintptr_t)
+ of_device_get_match_data(&client->dev);
+ }
+ chip->data = max17040_family[chip_id];

i2c_set_clientdata(client, chip);
psy_cfg.drv_data = chip;
@@ -324,11 +427,11 @@ static int max17040_probe(struct i2c_client *client,
return ret;
dev_dbg(&chip->client->dev, "MAX17040 Fuel-Gauge Ver 0x%x\n", ret);

- max17040_reset(chip);
+ if (chip_id == ID_MAX17040 || chip_id == ID_MAX17041)
+ max17040_reset(chip);

/* check interrupt */
- if (client->irq && of_device_is_compatible(client->dev.of_node,
- "maxim,max77836-battery")) {
+ if (client->irq && chip->data.has_low_soc_alert) {
ret = max17040_set_low_soc_alert(chip, chip->low_soc_alert);
if (ret) {
dev_err(&client->dev,
@@ -391,16 +494,30 @@ static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume);
#endif /* CONFIG_PM_SLEEP */

static const struct i2c_device_id max17040_id[] = {
- { "max17040" },
- { "max77836-battery" },
- { }
+ { "max17040", ID_MAX17040 },
+ { "max17041", ID_MAX17041 },
+ { "max17043", ID_MAX17043 },
+ { "max77836-battery", ID_MAX17043 },
+ { "max17044", ID_MAX17044 },
+ { "max17048", ID_MAX17048 },
+ { "max17049", ID_MAX17049 },
+ { "max17058", ID_MAX17058 },
+ { "max17059", ID_MAX17059 },
+ { /* sentinel */ }
};
MODULE_DEVICE_TABLE(i2c, max17040_id);

static const struct of_device_id max17040_of_match[] = {
- { .compatible = "maxim,max17040" },
- { .compatible = "maxim,max77836-battery" },
- { },
+ { .compatible = "maxim,max17040", .data = (void *) ID_MAX17040 },
+ { .compatible = "maxim,max17041", .data = (void *) ID_MAX17041 },
+ { .compatible = "maxim,max17043", .data = (void *) ID_MAX17043 },
+ { .compatible = "maxim,max77836-battery", .data = (void *) ID_MAX17043 },
+ { .compatible = "maxim,max17044", .data = (void *) ID_MAX17044 },
+ { .compatible = "maxim,max17048", .data = (void *) ID_MAX17048 },
+ { .compatible = "maxim,max17049", .data = (void *) ID_MAX17049 },
+ { .compatible = "maxim,max17058", .data = (void *) ID_MAX17058 },
+ { .compatible = "maxim,max17059", .data = (void *) ID_MAX17059 },
+ { /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, max17040_of_match);

--
2.28.0