[PATCH 1/2] power: supply: Add STC3117 fuel gauge unit driver

[PATCH 1/2] power: supply: Add STC3117 fuel gauge unit driver

[Bhavin Sharma]

Adding support for stc3117 fuel gauge driver with
minimal functionality to read voltage level currently

Signed-off-by: Bhavin Sharma <bhavin.sharma@siliconsignals.io>
---
 drivers/power/supply/Kconfig              |   7 ++
 drivers/power/supply/Makefile             |   1 +
 drivers/power/supply/stc3117_fuel_gauge.c | 136 ++++++++++++++++++++++
 3 files changed, 144 insertions(+)
 create mode 100644 drivers/power/supply/stc3117_fuel_gauge.c

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index f21cb05815ec..02df55b0d5f0 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -875,6 +875,13 @@ config FUEL_GAUGE_SC27XX
 	  Say Y here to enable support for fuel gauge with SC27XX
 	  PMIC chips.
 
+config FUEL_GAUGE_STC3117
+	tristate "STMicroelectronics STC3117 fuel gauge driver"
+	depends on I2C
+	help
+	  Say Y here to enable support for fuel gauge with STC3117
+	  PMIC chips.
+
 config CHARGER_UCS1002
 	tristate "Microchip UCS1002 USB Port Power Controller"
 	depends on I2C
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index 58b567278034..f8ed3e5a8882 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -104,6 +104,7 @@ obj-$(CONFIG_CHARGER_CROS_USBPD)	+= cros_usbpd-charger.o
 obj-$(CONFIG_CHARGER_CROS_PCHG)	+= cros_peripheral_charger.o
 obj-$(CONFIG_CHARGER_SC2731)	+= sc2731_charger.o
 obj-$(CONFIG_FUEL_GAUGE_SC27XX)	+= sc27xx_fuel_gauge.o
+obj-$(CONFIG_FUEL_GAUGE_STC3117)	+= stc3117_fuel_gauge.o
 obj-$(CONFIG_CHARGER_UCS1002)	+= ucs1002_power.o
 obj-$(CONFIG_CHARGER_BD99954)	+= bd99954-charger.o
 obj-$(CONFIG_CHARGER_WILCO)	+= wilco-charger.o
diff --git a/drivers/power/supply/stc3117_fuel_gauge.c b/drivers/power/supply/stc3117_fuel_gauge.c
new file mode 100644
index 000000000000..bb033ac54858
--- /dev/null
+++ b/drivers/power/supply/stc3117_fuel_gauge.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * stc3117_fuel_gauge.c - STMicroelectronics STC3117 Fuel Gauge Driver
+ *
+ * Copyright (c) 2024 Silicon Signals Pvt Ltd.
+ * Author:      Bhavin Sharma <bhavin.sharma@siliconsignals.io>
+ *              Hardevsinh Palaniya <hardevsinh.palaniya@siliconsignals.com>
+ */
+
+
+#include <linux/i2c.h>
+#include <linux/i2c-dev.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/power_supply.h>
+
+#define VOLTAGE_REG_ADDR	0x08
+#define VOLTAGE_REG_ADDR_SIZE	1		//in bytes
+#define VOLTAGE_DATA_SIZE	2		//in bytes
+#define LSB_VALUE		2200		//in micro-volts
+
+
+static int stc3117_probe(struct i2c_client *client);
+static void stc3117_dev_remove(struct i2c_client *client);
+
+static int stc3117_get_property(struct power_supply *psy,
+	enum power_supply_property psp, union power_supply_propval *val);
+static int stc3117_get_batt_volt(const struct i2c_client *client);
+
+const struct i2c_client *tmp_client;
+struct power_supply *stc_sply;
+
+static const struct of_device_id stc3117_of_match[] = {
+	{ .compatible = "st,stc3117-fgu" },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, stc3117_of_match);
+
+static const struct i2c_device_id stc3117_id[] = {
+	{"stc3117", 0},
+	{},
+};
+
+
+MODULE_DEVICE_TABLE(i2c, stc3117_id);
+
+struct i2c_driver stc3117_i2c_driver = {
+	.driver = {
+		.name = "stc3117_i2c_driver",
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(stc3117_of_match),
+	},
+	.probe = stc3117_probe,
+	.id_table = stc3117_id,
+	.remove = stc3117_dev_remove,
+};
+
+
+static enum power_supply_property stc3117_battery_props[] = {
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+};
+
+static const struct power_supply_desc stc3117_battery_desc = {
+	.name = "stc3117-battery",
+	.type = POWER_SUPPLY_TYPE_BATTERY,
+	.get_property = stc3117_get_property,
+	.properties = stc3117_battery_props,
+	.num_properties = ARRAY_SIZE(stc3117_battery_props),
+};
+
+static int stc3117_get_property(struct power_supply *psy,
+	enum power_supply_property psp, union power_supply_propval *val)
+{
+	switch (psp) {
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		val->intval = stc3117_get_batt_volt(tmp_client);
+	break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+
+static int stc3117_get_batt_volt(const struct i2c_client *stc_client)
+{
+	int ret, volt = 0;
+	char i2c_tx = VOLTAGE_REG_ADDR, i2c_rx[2] = {0};
+
+	ret = i2c_master_send(stc_client, &i2c_tx, VOLTAGE_REG_ADDR_SIZE);
+	if (ret > 0) {
+
+		ret = i2c_master_recv(stc_client, i2c_rx, VOLTAGE_DATA_SIZE);
+		if (ret > 0) {
+
+			volt = (i2c_rx[1] << 8) + i2c_rx[0];
+			volt *= LSB_VALUE;
+
+			return volt;
+		}
+	}
+
+	return ret;
+}
+
+static int stc3117_probe(struct i2c_client *client)
+{
+	struct power_supply_config psy_cfg = {};
+	struct device *dev;
+
+	dev = &client->dev;
+
+	psy_cfg.of_node = dev->of_node;
+
+	tmp_client = client;
+
+	stc_sply = power_supply_register(dev, &stc3117_battery_desc, &psy_cfg);
+	if (IS_ERR(stc_sply))
+		pr_err("failed to register battery\n");
+
+	return 0;
+}
+
+static void stc3117_dev_remove(struct i2c_client *client)
+{
+	power_supply_unregister(stc_sply);
+}
+
+module_i2c_driver(stc3117_i2c_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Bhavin Sharma <bhavin.sharma@siliconsignals.io>");
+MODULE_AUTHOR("Hardevsinh Palaniya <hardevsinh.palaniya@siliconsignals.io>");
+MODULE_DESCRIPTION("STC3117 Fuel Gauge Driver");
+MODULE_VERSION("v1.0");
+
-- 
2.34.1

[PATCH 2/2] dt-bindings: power: supply: stc3117: Convert to DT schema format

[Bhavin Sharma]

Convert the binding to DT schema format.

Signed-off-by: Bhavin Sharma <bhavin.sharma@siliconsignals.io>
---
 .../bindings/power/supply/stc3117-fg.yaml     | 42 +++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/power/supply/stc3117-fg.yaml

diff --git a/Documentation/devicetree/bindings/power/supply/stc3117-fg.yaml b/Documentation/devicetree/bindings/power/supply/stc3117-fg.yaml
new file mode 100644
index 000000000000..2c33132ab785
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/supply/stc3117-fg.yaml
@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: GPL-2.0-only
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/power/supply/sc27xx-fg.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: STMicroelectronics STC3117 Fuel Gauge Unit Power Supply Bindings
+
+maintainers:
+  - Bhavin Sharma <bhavin.sharma@siliconsignals.io>
+  - Hardevsinh Palaniya <hardevsinh.palaniya@siliconsignals.io>
+
+allOf:
+  - $ref: power-supply.yaml#
+
+properties:
+  compatible:
+    enum:
+      - st,stc3117-fgu
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    &i2c6 {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      st3117: stc3117@70 {
+        compatible = "st,stc3117-fgu";
+        reg = <0x70>;
+	status = "okay";
+      };
+    };
+
-- 
2.34.1

Re: [PATCH 2/2] dt-bindings: power: supply: stc3117: Convert to DT schema format

[Rob Herring]

On Sat, 06 Jan 2024 15:44:34 +0530, Bhavin Sharma wrote:
> Convert the binding to DT schema format.
> 
> Signed-off-by: Bhavin Sharma <bhavin.sharma@siliconsignals.io>
> ---
>  .../bindings/power/supply/stc3117-fg.yaml     | 42 +++++++++++++++++++
>  1 file changed, 42 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/power/supply/stc3117-fg.yaml
> 

My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
on your patch (DT_CHECKER_FLAGS is new in v5.13):

yamllint warnings/errors:
./Documentation/devicetree/bindings/power/supply/stc3117-fg.yaml:4:6: [error] string value is redundantly quoted with any quotes (quoted-strings)
./Documentation/devicetree/bindings/power/supply/stc3117-fg.yaml:5:10: [error] string value is redundantly quoted with any quotes (quoted-strings)
./Documentation/devicetree/bindings/power/supply/stc3117-fg.yaml:39:1: [error] syntax error: found character '\t' that cannot start any token (syntax)

dtschema/dtc warnings/errors:
make[2]: *** Deleting file 'Documentation/devicetree/bindings/power/supply/stc3117-fg.example.dts'
Documentation/devicetree/bindings/power/supply/stc3117-fg.yaml:39:1: found a tab character where an indentation space is expected
make[2]: *** [Documentation/devicetree/bindings/Makefile:26: Documentation/devicetree/bindings/power/supply/stc3117-fg.example.dts] Error 1
make[2]: *** Waiting for unfinished jobs....
./Documentation/devicetree/bindings/power/supply/stc3117-fg.yaml:39:1: found a tab character where an indentation space is expected
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/power/supply/stc3117-fg.yaml: ignoring, error parsing file
make[1]: *** [/builds/robherring/dt-review-ci/linux/Makefile:1424: dt_binding_check] Error 2
make: *** [Makefile:234: __sub-make] Error 2

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20240106101435.2927116-2-bhavin.sharma@siliconsignals.io

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.

Re: [PATCH 1/2] power: supply: Add STC3117 fuel gauge unit driver

[Christophe JAILLET]

Le 06/01/2024 à 11:14, Bhavin Sharma a écrit :
> Adding support for stc3117 fuel gauge driver with
> minimal functionality to read voltage level currently
> 
> Signed-off-by: Bhavin Sharma <bhavin.sharma-TXG9oGKWPboh9/7i5KS7/GGXanvQGlWp@public.gmane.org>
> ---

Hi,

>   drivers/power/supply/Kconfig              |   7 ++
>   drivers/power/supply/Makefile             |   1 +
>   drivers/power/supply/stc3117_fuel_gauge.c | 136 ++++++++++++++++++++++
>   3 files changed, 144 insertions(+)
>   create mode 100644 drivers/power/supply/stc3117_fuel_gauge.c
> 
> diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
> index f21cb05815ec..02df55b0d5f0 100644
> --- a/drivers/power/supply/Kconfig
> +++ b/drivers/power/supply/Kconfig
> @@ -875,6 +875,13 @@ config FUEL_GAUGE_SC27XX
>   	  Say Y here to enable support for fuel gauge with SC27XX
>   	  PMIC chips.
>   
> +config FUEL_GAUGE_STC3117
> +	tristate "STMicroelectronics STC3117 fuel gauge driver"
> +	depends on I2C
> +	help
> +	  Say Y here to enable support for fuel gauge with STC3117
> +	  PMIC chips.
> +
>   config CHARGER_UCS1002
>   	tristate "Microchip UCS1002 USB Port Power Controller"
>   	depends on I2C
> diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
> index 58b567278034..f8ed3e5a8882 100644
> --- a/drivers/power/supply/Makefile
> +++ b/drivers/power/supply/Makefile
> @@ -104,6 +104,7 @@ obj-$(CONFIG_CHARGER_CROS_USBPD)	+= cros_usbpd-charger.o
>   obj-$(CONFIG_CHARGER_CROS_PCHG)	+= cros_peripheral_charger.o
>   obj-$(CONFIG_CHARGER_SC2731)	+= sc2731_charger.o
>   obj-$(CONFIG_FUEL_GAUGE_SC27XX)	+= sc27xx_fuel_gauge.o
> +obj-$(CONFIG_FUEL_GAUGE_STC3117)	+= stc3117_fuel_gauge.o
>   obj-$(CONFIG_CHARGER_UCS1002)	+= ucs1002_power.o
>   obj-$(CONFIG_CHARGER_BD99954)	+= bd99954-charger.o
>   obj-$(CONFIG_CHARGER_WILCO)	+= wilco-charger.o
> diff --git a/drivers/power/supply/stc3117_fuel_gauge.c b/drivers/power/supply/stc3117_fuel_gauge.c
> new file mode 100644
> index 000000000000..bb033ac54858
> --- /dev/null
> +++ b/drivers/power/supply/stc3117_fuel_gauge.c
> @@ -0,0 +1,136 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * stc3117_fuel_gauge.c - STMicroelectronics STC3117 Fuel Gauge Driver
> + *
> + * Copyright (c) 2024 Silicon Signals Pvt Ltd.
> + * Author:      Bhavin Sharma <bhavin.sharma-TXG9oGKWPboh9/7i5KS7/GGXanvQGlWp@public.gmane.org>
> + *              Hardevsinh Palaniya <hardevsinh.palaniya-TXG9oGKWPbrc8hPZMNZi9dBPR1lH4CV8@public.gmane.org>
> + */
> +
> +

Only 1 NL is enough.

> +#include <linux/i2c.h>
> +#include <linux/i2c-dev.h>
> +#include <linux/kernel.h>

Is it really needed for a small driver like this?

> +#include <linux/module.h>
> +#include <linux/uaccess.h>
> +#include <linux/power_supply.h>

Keep alphabetical order.

> +
> +#define VOLTAGE_REG_ADDR	0x08
> +#define VOLTAGE_REG_ADDR_SIZE	1		//in bytes
> +#define VOLTAGE_DATA_SIZE	2		//in bytes
> +#define LSB_VALUE		2200		//in micro-volts
> +
> +
> +static int stc3117_probe(struct i2c_client *client);
> +static void stc3117_dev_remove(struct i2c_client *client);

If struct i2c_driver stc3117_i2c_driver was declared at the end of the 
fine, these prototypes could be removed.

> +
> +static int stc3117_get_property(struct power_supply *psy,
> +	enum power_supply_property psp, union power_supply_propval *val);
> +static int stc3117_get_batt_volt(const struct i2c_client *client);

Same here.
I think that a different ordering could avoid these prototypes.

> +
> +const struct i2c_client *tmp_client;
> +struct power_supply *stc_sply;
> +
> +static const struct of_device_id stc3117_of_match[] = {
> +	{ .compatible = "st,stc3117-fgu" },
> +	{},
> +};
> +
> +MODULE_DEVICE_TABLE(of, stc3117_of_match);
> +
> +static const struct i2c_device_id stc3117_id[] = {
> +	{"stc3117", 0},
> +	{},
> +};
> +
> +

Only 1 NL is enough.

> +MODULE_DEVICE_TABLE(i2c, stc3117_id);
> +
> +struct i2c_driver stc3117_i2c_driver = {
> +	.driver = {
> +		.name = "stc3117_i2c_driver",
> +		.owner = THIS_MODULE,
> +		.of_match_table = of_match_ptr(stc3117_of_match),
> +	},
> +	.probe = stc3117_probe,
> +	.id_table = stc3117_id,
> +	.remove = stc3117_dev_remove,
> +};
> +
> +

Only 1 NL is enough.

> +static enum power_supply_property stc3117_battery_props[] = {
> +	POWER_SUPPLY_PROP_VOLTAGE_NOW,
> +};
> +
> +static const struct power_supply_desc stc3117_battery_desc = {
> +	.name = "stc3117-battery",
> +	.type = POWER_SUPPLY_TYPE_BATTERY,
> +	.get_property = stc3117_get_property,
> +	.properties = stc3117_battery_props,
> +	.num_properties = ARRAY_SIZE(stc3117_battery_props),
> +};
> +
> +static int stc3117_get_property(struct power_supply *psy,
> +	enum power_supply_property psp, union power_supply_propval *val)
> +{
> +	switch (psp) {
> +	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
> +		val->intval = stc3117_get_batt_volt(tmp_client);
> +	break;

This break should be indented by 1 more tab.

> +	default:
> +		return -EINVAL;
> +	}
> +	return 0;
> +}
> +
> +

Only 1 NL is enough.

> +static int stc3117_get_batt_volt(const struct i2c_client *stc_client)
> +{
> +	int ret, volt = 0;
> +	char i2c_tx = VOLTAGE_REG_ADDR, i2c_rx[2] = {0};

Maybe VOLTAGE_DATA_SIZE, instead of 2?

> +
> +	ret = i2c_master_send(stc_client, &i2c_tx, VOLTAGE_REG_ADDR_SIZE);
> +	if (ret > 0) {
> +
> +		ret = i2c_master_recv(stc_client, i2c_rx, VOLTAGE_DATA_SIZE);
> +		if (ret > 0) {
> +
> +			volt = (i2c_rx[1] << 8) + i2c_rx[0];
> +			volt *= LSB_VALUE;
> +
> +			return volt;
> +		}
> +	}
> +
> +	return ret;
> +}

Writting it as:
   ret = i2c_master_send()
   if (ret < 0)
	return ret;

   ret = i2c_master_recv();
   if (ret < 0)
	return ret;

   vols = ...

would save some indentation.

> +
> +static int stc3117_probe(struct i2c_client *client)
> +{
> +	struct power_supply_config psy_cfg = {};
> +	struct device *dev;
> +
> +	dev = &client->dev;
> +
> +	psy_cfg.of_node = dev->of_node;
> +
> +	tmp_client = client;
> +
> +	stc_sply = power_supply_register(dev, &stc3117_battery_desc, &psy_cfg);

devm_power_supply_register() ?
This would remove the need of the .remove() function.

> +	if (IS_ERR(stc_sply))
> +		pr_err("failed to register battery\n");

dev_err()?

Maybe this error code should be propagated. What the point of this 
driver if this function fails?

just my 2c,

CJ

> +
> +	return 0;
> +}
> +
> +static void stc3117_dev_remove(struct i2c_client *client)
> +{
> +	power_supply_unregister(stc_sply);
> +}
> +
> +module_i2c_driver(stc3117_i2c_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Bhavin Sharma <bhavin.sharma-TXG9oGKWPboh9/7i5KS7/GGXanvQGlWp@public.gmane.org>");
> +MODULE_AUTHOR("Hardevsinh Palaniya <hardevsinh.palaniya-TXG9oGKWPboh9/7i5KS7/GGXanvQGlWp@public.gmane.org>");
> +MODULE_DESCRIPTION("STC3117 Fuel Gauge Driver");
> +MODULE_VERSION("v1.0");
> +