[PATCH v8 0/5] power: supply: MAX17040: Add IRQ for low level and alert SOC changes

[PATCH v8 0/5] power: supply: MAX17040: Add IRQ for low level and alert SOC changes

[Matheus Castello]

This series add IRQ handler for low level SOC alert, define a devicetree
binding attribute to configure the alert level threshold and check for
changes in SOC and power supply status for send uevents.

Max17043/17044 have a pin for alert host about low level state of charge and
this alert can be configured in a threshold from 1% up to 32% of SOC.

Thanks Krzysztof Kozlowski, Lee Jones, Rob Herring and Sebastian Reichel for
your time reviewing it.

Changes since v7:
(Suggested by Sebastian Reichel)
- Fix unrelated change
- Use device_property_read_u32() and simplify the code
- Check the irq and of_device_is_compatible in the first patch

Changes since v6:
(Suggested by Lee Jones)
- Use relative paths in documentation

Matheus Castello (5):
  power: supply: max17040: Add IRQ handler for low SOC alert
  dt-bindings: power: supply: Max17040: Add DT bindings for max17040
    fuel gauge
  devicetree: mfd: max14577: Add reference to max14040_battery.txt
    descriptions
  power: supply: max17040: Config alert SOC low level threshold from FDT
  power: supply: max17040: Send uevent in SOC and status change

 .../devicetree/bindings/mfd/max14577.txt      |   2 +
 .../power/supply/max17040_battery.txt         |  33 +++++
 drivers/power/supply/max17040_battery.c       | 130 +++++++++++++++++-
 3 files changed, 161 insertions(+), 4 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/power/supply/max17040_battery.txt

--
2.24.0.rc2

[PATCH v8 1/5] power: supply: max17040: Add IRQ handler for low SOC alert

[Matheus Castello]

According datasheet max17040 has a pin for alert host for low SOC.
This pin can be used as external interrupt, so we need to check for
interrupts assigned for device and handle it.

In handler we are checking and storing fuel gauge registers values
and send an uevent to notificate user space, so user space can decide
save work or turn off since the alert demonstrate that the battery may
no have the power to keep the system turned on for much longer.

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 drivers/power/supply/max17040_battery.c | 73 +++++++++++++++++++++++--
 1 file changed, 68 insertions(+), 5 deletions(-)

diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c
index 62499018e68b..5a8cd365a61e 100644
--- a/drivers/power/supply/max17040_battery.c
+++ b/drivers/power/supply/max17040_battery.c
@@ -13,6 +13,7 @@
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/delay.h>
+#include <linux/interrupt.h>
 #include <linux/power_supply.h>
 #include <linux/max17040_battery.h>
 #include <linux/slab.h>
@@ -160,21 +161,54 @@ static void max17040_get_status(struct i2c_client *client)
 		chip->status = POWER_SUPPLY_STATUS_FULL;
 }

+static void max17040_check_changes(struct i2c_client *client)
+{
+	max17040_get_vcell(client);
+	max17040_get_soc(client);
+	max17040_get_online(client);
+	max17040_get_status(client);
+}
+
 static void max17040_work(struct work_struct *work)
 {
 	struct max17040_chip *chip;

 	chip = container_of(work, struct max17040_chip, work.work);
-
-	max17040_get_vcell(chip->client);
-	max17040_get_soc(chip->client);
-	max17040_get_online(chip->client);
-	max17040_get_status(chip->client);
+	max17040_check_changes(chip->client);

 	queue_delayed_work(system_power_efficient_wq, &chip->work,
 			   MAX17040_DELAY);
 }

+static irqreturn_t max17040_thread_handler(int id, void *dev)
+{
+	struct max17040_chip *chip = dev;
+	struct i2c_client *client = chip->client;
+
+	dev_warn(&client->dev, "IRQ: Alert battery low level");
+	/* read registers */
+	max17040_check_changes(chip->client);
+
+	/* send uevent */
+	power_supply_changed(chip->battery);
+
+	return IRQ_HANDLED;
+}
+
+static int max17040_enable_alert_irq(struct max17040_chip *chip)
+{
+	struct i2c_client *client = chip->client;
+	unsigned int flags;
+	int ret;
+
+	flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT;
+	ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
+					max17040_thread_handler, flags,
+					chip->battery->desc->name, chip);
+
+	return ret;
+}
+
 static enum power_supply_property max17040_battery_props[] = {
 	POWER_SUPPLY_PROP_STATUS,
 	POWER_SUPPLY_PROP_ONLINE,
@@ -220,6 +254,19 @@ static int max17040_probe(struct i2c_client *client,
 	max17040_reset(client);
 	max17040_get_version(client);

+	/* check interrupt */
+	if (client->irq && of_device_is_compatible(client->dev.of_node,
+						   "maxim,max77836-battery")) {
+		int ret;
+
+		ret = max17040_enable_alert_irq(chip);
+		if (ret) {
+			client->irq = 0;
+			dev_warn(&client->dev,
+				 "Failed to get IRQ err %d\n", ret);
+		}
+	}
+
 	INIT_DEFERRABLE_WORK(&chip->work, max17040_work);
 	queue_delayed_work(system_power_efficient_wq, &chip->work,
 			   MAX17040_DELAY);
@@ -244,6 +291,14 @@ static int max17040_suspend(struct device *dev)
 	struct max17040_chip *chip = i2c_get_clientdata(client);

 	cancel_delayed_work(&chip->work);
+
+	if (client->irq) {
+		if (device_may_wakeup(dev))
+			enable_irq_wake(client->irq);
+		else
+			disable_irq_wake(client->irq);
+	}
+
 	return 0;
 }

@@ -254,6 +309,14 @@ static int max17040_resume(struct device *dev)

 	queue_delayed_work(system_power_efficient_wq, &chip->work,
 			   MAX17040_DELAY);
+
+	if (client->irq) {
+		if (device_may_wakeup(dev))
+			disable_irq_wake(client->irq);
+		else
+			enable_irq_wake(client->irq);
+	}
+
 	return 0;
 }

--
2.24.0.rc2

[PATCH v8 2/5] dt-bindings: power: supply: Max17040: Add DT bindings for max17040 fuel gauge

[Matheus Castello]

Documentation of max17040 based fuel gauge characteristics.
For configure low level state of charge threshold alert signaled from
max17043/max17044 we add "maxim,alert-low-soc-level" property.

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../power/supply/max17040_battery.txt         | 33 +++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/power/supply/max17040_battery.txt

diff --git a/Documentation/devicetree/bindings/power/supply/max17040_battery.txt b/Documentation/devicetree/bindings/power/supply/max17040_battery.txt
new file mode 100644
index 000000000000..f2d0b22b5f79
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/supply/max17040_battery.txt
@@ -0,0 +1,33 @@
+max17040_battery
+~~~~~~~~~~~~~~~~
+
+Required properties :
+ - compatible : "maxim,max17040" or "maxim,max77836-battery"
+ - reg: i2c slave address
+
+Optional properties :
+- maxim,alert-low-soc-level :	The alert threshold that sets the state of
+ 				charge level (%) where an interrupt is
+				generated. Can be configured from 1 up to 32
+				(%). If skipped the power up default value of
+				4 (%) will be used.
+- interrupts : 			Interrupt line see Documentation/devicetree/
+				bindings/interrupt-controller/interrupts.txt
+- wakeup-source :		This device has wakeup capabilities. Use this
+				property to use alert low SOC level interrupt
+				as wake up source.
+
+Optional properties support interrupt functionality for alert low state of
+charge level, present in some ICs in the same family, and should be used with
+compatible "maxim,max77836-battery".
+
+Example:
+
+	battery-fuel-gauge@36 {
+		compatible = "maxim,max77836-battery";
+		reg = <0x36>;
+		maxim,alert-low-soc-level = <10>;
+		interrupt-parent = <&gpio7>;
+		interrupts = <2 IRQ_TYPE_EDGE_FALLING>;
+		wakeup-source;
+	};
--
2.24.0.rc2

[PATCH v8 3/5] devicetree: mfd: max14577: Add reference to max14040_battery.txt descriptions

[Matheus Castello]

max77836 MFD has a fuel gauge that has a low SOC alert feature that is
described in Documentation/devicetree/bindings/power/supply/max17040_battery.txt.
Adding the reference to de documentation here.

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/mfd/max14577.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/mfd/max14577.txt b/Documentation/devicetree/bindings/mfd/max14577.txt
index fc6f0f4e8beb..45c7f414aee0 100644
--- a/Documentation/devicetree/bindings/mfd/max14577.txt
+++ b/Documentation/devicetree/bindings/mfd/max14577.txt
@@ -5,6 +5,8 @@ Battery Charger and SFOUT LDO output for powering USB devices. It is
 interfaced to host controller using I2C.

 MAX77836 additionally contains PMIC (with two LDO regulators) and Fuel Gauge.
+For the description of Fuel Gauge low SOC alert interrupt see:
+power/supply/max17040_battery.txt


 Required properties:
--
2.24.0.rc2

Re: [PATCH v8 3/5] devicetree: mfd: max14577: Add reference to max14040_battery.txt descriptions

[Krzysztof Kozlowski]

On Thu, Dec 05, 2019 at 12:44:08PM -0300, Matheus Castello wrote:
> max77836 MFD has a fuel gauge that has a low SOC alert feature that is
> described in Documentation/devicetree/bindings/power/supply/max17040_battery.txt.
> Adding the reference to de documentation here.

The subject prefix should be:
dt-bindings: mfd: max14577: ...

Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>

Best regards,
Krzysztof


> 
> Signed-off-by: Matheus Castello <matheus@castello.eng.br>
> Acked-by: Lee Jones <lee.jones@linaro.org>
> Acked-by: Rob Herring <robh@kernel.org>
> ---
>  Documentation/devicetree/bindings/mfd/max14577.txt | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mfd/max14577.txt b/Documentation/devicetree/bindings/mfd/max14577.txt
> index fc6f0f4e8beb..45c7f414aee0 100644
> --- a/Documentation/devicetree/bindings/mfd/max14577.txt
> +++ b/Documentation/devicetree/bindings/mfd/max14577.txt
> @@ -5,6 +5,8 @@ Battery Charger and SFOUT LDO output for powering USB devices. It is
>  interfaced to host controller using I2C.
> 
>  MAX77836 additionally contains PMIC (with two LDO regulators) and Fuel Gauge.
> +For the description of Fuel Gauge low SOC alert interrupt see:
> +power/supply/max17040_battery.txt
> 
> 
>  Required properties:
> --
> 2.24.0.rc2
> 

Re: [PATCH v8 3/5] devicetree: mfd: max14577: Add reference to max14040_battery.txt descriptions

[Lee Jones]

On Thu, 05 Dec 2019, Matheus Castello wrote:

> max77836 MFD has a fuel gauge that has a low SOC alert feature that is
> described in Documentation/devicetree/bindings/power/supply/max17040_battery.txt.
> Adding the reference to de documentation here.
> 
> Signed-off-by: Matheus Castello <matheus@castello.eng.br>
> Acked-by: Lee Jones <lee.jones@linaro.org>
> Acked-by: Rob Herring <robh@kernel.org>
> ---
>  Documentation/devicetree/bindings/mfd/max14577.txt | 2 ++
>  1 file changed, 2 insertions(+)

Applied, thanks.

-- 
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

[PATCH v8 4/5] power: supply: max17040: Config alert SOC low level threshold from FDT

[Matheus Castello]

For configuration of fuel gauge alert for a low level state of charge
interrupt we add a function to config level threshold and a device tree
binding property to set it in flatned device tree node.

Now we can use "maxim,alert-low-soc-level" property with the values from
1% up to 32% to configure alert interrupt threshold.

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
---
 drivers/power/supply/max17040_battery.c | 52 ++++++++++++++++++++++++-
 1 file changed, 51 insertions(+), 1 deletion(-)

diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c
index 5a8cd365a61e..2a2a1fd8d4eb 100644
--- a/drivers/power/supply/max17040_battery.c
+++ b/drivers/power/supply/max17040_battery.c
@@ -29,6 +29,9 @@
 #define MAX17040_DELAY		1000
 #define MAX17040_BATTERY_FULL	95

+#define MAX17040_ATHD_MASK		0xFFC0
+#define MAX17040_ATHD_DEFAULT_POWER_UP	4
+
 struct max17040_chip {
 	struct i2c_client		*client;
 	struct delayed_work		work;
@@ -43,6 +46,8 @@ struct max17040_chip {
 	int soc;
 	/* State Of Charge */
 	int status;
+	/* Low alert threshold from 32% to 1% of the State of Charge */
+	u32 low_soc_alert;
 };

 static int max17040_get_property(struct power_supply *psy,
@@ -99,6 +104,21 @@ static void max17040_reset(struct i2c_client *client)
 	max17040_write_reg(client, MAX17040_CMD, 0x0054);
 }

+static int max17040_set_low_soc_alert(struct i2c_client *client, u32 level)
+{
+	int ret;
+	u16 data;
+
+	level = 32 - level;
+	data = max17040_read_reg(client, MAX17040_RCOMP);
+	/* clear the alrt bit and set LSb 5 bits */
+	data &= MAX17040_ATHD_MASK;
+	data |= level;
+	ret = max17040_write_reg(client, MAX17040_RCOMP, data);
+
+	return ret;
+}
+
 static void max17040_get_vcell(struct i2c_client *client)
 {
 	struct max17040_chip *chip = i2c_get_clientdata(client);
@@ -161,6 +181,21 @@ static void max17040_get_status(struct i2c_client *client)
 		chip->status = POWER_SUPPLY_STATUS_FULL;
 }

+static int max17040_get_of_data(struct max17040_chip *chip)
+{
+	struct device *dev = &chip->client->dev;
+
+	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)
+		return -EINVAL;
+
+	return 0;
+}
+
 static void max17040_check_changes(struct i2c_client *client)
 {
 	max17040_get_vcell(client);
@@ -192,6 +227,9 @@ static irqreturn_t max17040_thread_handler(int id, void *dev)
 	/* send uevent */
 	power_supply_changed(chip->battery);

+	/* reset alert bit */
+	max17040_set_low_soc_alert(client, chip->low_soc_alert);
+
 	return IRQ_HANDLED;
 }

@@ -230,6 +268,7 @@ static int max17040_probe(struct i2c_client *client,
 	struct i2c_adapter *adapter = client->adapter;
 	struct power_supply_config psy_cfg = {};
 	struct max17040_chip *chip;
+	int ret;

 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
 		return -EIO;
@@ -240,6 +279,12 @@ static int max17040_probe(struct i2c_client *client,

 	chip->client = client;
 	chip->pdata = client->dev.platform_data;
+	ret = max17040_get_of_data(chip);
+	if (ret) {
+		dev_err(&client->dev,
+			"failed: low SOC alert OF data out of bounds\n");
+		return ret;
+	}

 	i2c_set_clientdata(client, chip);
 	psy_cfg.drv_data = chip;
@@ -257,7 +302,12 @@ static int max17040_probe(struct i2c_client *client,
 	/* check interrupt */
 	if (client->irq && of_device_is_compatible(client->dev.of_node,
 						   "maxim,max77836-battery")) {
-		int ret;
+		ret = max17040_set_low_soc_alert(client, chip->low_soc_alert);
+		if (ret) {
+			dev_err(&client->dev,
+				"Failed to set low SOC alert: err %d\n", ret);
+			return ret;
+		}

 		ret = max17040_enable_alert_irq(chip);
 		if (ret) {
--
2.24.0.rc2

Re: [PATCH v8 4/5] power: supply: max17040: Config alert SOC low level threshold from FDT

[Krzysztof Kozlowski]

On Thu, Dec 05, 2019 at 12:44:09PM -0300, Matheus Castello wrote:
> For configuration of fuel gauge alert for a low level state of charge
> interrupt we add a function to config level threshold and a device tree
> binding property to set it in flatned device tree node.
> 
> Now we can use "maxim,alert-low-soc-level" property with the values from
> 1% up to 32% to configure alert interrupt threshold.
> 
> Signed-off-by: Matheus Castello <matheus@castello.eng.br>
> ---
>  drivers/power/supply/max17040_battery.c | 52 ++++++++++++++++++++++++-
>  1 file changed, 51 insertions(+), 1 deletion(-)

Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>

Best regards,
Krzysztof

[PATCH v8 5/5] power: supply: max17040: Send uevent in SOC and status change

[Matheus Castello]

Notify core through power_supply_changed() in case of changes in state
of charge and power supply status. This is useful for user-space to
efficiently update current battery level.

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 drivers/power/supply/max17040_battery.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c
index 2a2a1fd8d4eb..c1188e94cf54 100644
--- a/drivers/power/supply/max17040_battery.c
+++ b/drivers/power/supply/max17040_battery.c
@@ -207,10 +207,19 @@ static void max17040_check_changes(struct i2c_client *client)
 static void max17040_work(struct work_struct *work)
 {
 	struct max17040_chip *chip;
+	int last_soc, last_status;

 	chip = container_of(work, struct max17040_chip, work.work);
+
+	/* store SOC and status to check changes */
+	last_soc = chip->soc;
+	last_status = chip->status;
 	max17040_check_changes(chip->client);

+	/* check changes and send uevent */
+	if (last_soc != chip->soc || last_status != chip->status)
+		power_supply_changed(chip->battery);
+
 	queue_delayed_work(system_power_efficient_wq, &chip->work,
 			   MAX17040_DELAY);
 }
--
2.24.0.rc2

Re: [PATCH v8 0/5] power: supply: MAX17040: Add IRQ for low level and alert SOC changes

[Sebastian Reichel]

[-- Attachment #1: Type: text/plain, Size: 1738 bytes --]

Hi,

On Thu, Dec 05, 2019 at 12:44:05PM -0300, Matheus Castello wrote:
> This series add IRQ handler for low level SOC alert, define a devicetree
> binding attribute to configure the alert level threshold and check for
> changes in SOC and power supply status for send uevents.
> 
> Max17043/17044 have a pin for alert host about low level state of charge and
> this alert can be configured in a threshold from 1% up to 32% of SOC.
> 
> Thanks Krzysztof Kozlowski, Lee Jones, Rob Herring and Sebastian Reichel for
> your time reviewing it.

Thanks, I queued all but the MFD patch to power-supply's for-next
branch.

-- Sebastian

> Changes since v7:
> (Suggested by Sebastian Reichel)
> - Fix unrelated change
> - Use device_property_read_u32() and simplify the code
> - Check the irq and of_device_is_compatible in the first patch
> 
> Changes since v6:
> (Suggested by Lee Jones)
> - Use relative paths in documentation
> 
> Matheus Castello (5):
>   power: supply: max17040: Add IRQ handler for low SOC alert
>   dt-bindings: power: supply: Max17040: Add DT bindings for max17040
>     fuel gauge
>   devicetree: mfd: max14577: Add reference to max14040_battery.txt
>     descriptions
>   power: supply: max17040: Config alert SOC low level threshold from FDT
>   power: supply: max17040: Send uevent in SOC and status change
> 
>  .../devicetree/bindings/mfd/max14577.txt      |   2 +
>  .../power/supply/max17040_battery.txt         |  33 +++++
>  drivers/power/supply/max17040_battery.c       | 130 +++++++++++++++++-
>  3 files changed, 161 insertions(+), 4 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/power/supply/max17040_battery.txt
> 
> --
> 2.24.0.rc2
> 

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