[PATCH v3 0/5] Introduce Embedded Controller driver for Acer A500

[PATCH v3 0/5] Introduce Embedded Controller driver for Acer A500

[Dmitry Osipenko]

Hello!

This series adds support for the Embedded Controller which is found on
Acer Iconia Tab A500 (Android tablet device).

The Embedded Controller is ENE KB930 and it's running firmware customized
for the A500. The firmware interface may be reused by some other sibling
Acer tablets, although none of those tablets are supported in upstream yet.
Please review and apply, thanks in advance!

Changelog:

v3: - Rebased on a recent linux-next. Fixed new merge conflict and dropped
      "regmap: Use flexible sleep" patch because it's already applied.

v2: - Factored out KB930 device-tree binding into a separate file, like it
      was suggested by Lubomir Rintel.

    - Switched to use regmap API like it was suggested by Lubomir Rintel.

    - Added patch "regmap: Use flexible sleep" which allows not to hog
      CPU while LED is switching state.

    - Corrected MODULE_LICENSE to use "GPL" in all patches.

    - Corrected MFD driver Kconfig entry like it was suggested by
      Lubomir Rintel, it now depends on I2C.

    - Switched to use I2C probe_new() in the MFD driver.

    - Renamed the global pm_off variable, like it was suggested by
      Lubomir Rintel and Lee Jones.

    - Dropped serial number from the battery driver because I realized
      that it's not a battery serial, but a device serial.

    - Battery driver now uses dev_err_probe(), like it was suggested by
      Sebastian Reichel.

    - Dropped legacy LED_ON usage from the LED driver and renamed the
      LEDs, like it was suggested by Pavel Machek. I also checked whether
      LED-name customization via device-tree could be needed by other
      potentially compatible devices and it shouldn't be needed, anyways it
      won't be difficult to extend the code even if I'm wrong.

Dmitry Osipenko (5):
  dt-bindings: mfd: Add ENE KB930 Embedded Controller binding
  mfd: Add driver for Embedded Controller found on Acer Iconia Tab A500
  power: supply: Add battery gauge driver for Acer Iconia Tab A500
  leds: Add driver for Acer Iconia Tab A500
  ARM: tegra: acer-a500: Add Embedded Controller

 .../devicetree/bindings/mfd/ene-kb930.yaml    |  66 ++++
 .../boot/dts/tegra20-acer-a500-picasso.dts    |  17 +
 drivers/leds/Kconfig                          |   7 +
 drivers/leds/Makefile                         |   1 +
 drivers/leds/leds-acer-a500.c                 | 129 ++++++++
 drivers/mfd/Kconfig                           |  12 +
 drivers/mfd/Makefile                          |   1 +
 drivers/mfd/acer-ec-a500.c                    | 203 ++++++++++++
 drivers/power/supply/Kconfig                  |   6 +
 drivers/power/supply/Makefile                 |   1 +
 drivers/power/supply/acer_a500_battery.c      | 297 ++++++++++++++++++
 11 files changed, 740 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/ene-kb930.yaml
 create mode 100644 drivers/leds/leds-acer-a500.c
 create mode 100644 drivers/mfd/acer-ec-a500.c
 create mode 100644 drivers/power/supply/acer_a500_battery.c

-- 
2.27.0

[PATCH v3 1/5] dt-bindings: mfd: Add ENE KB930 Embedded Controller binding

[Dmitry Osipenko]

Add binding document for the ENE KB930 Embedded Controller.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 .../devicetree/bindings/mfd/ene-kb930.yaml    | 66 +++++++++++++++++++
 1 file changed, 66 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/ene-kb930.yaml

diff --git a/Documentation/devicetree/bindings/mfd/ene-kb930.yaml b/Documentation/devicetree/bindings/mfd/ene-kb930.yaml
new file mode 100644
index 000000000000..635c8966ca22
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/ene-kb930.yaml
@@ -0,0 +1,66 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/ene-kb930.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ENE KB930 Embedded Controller bindings
+
+description: |
+  This binding describes the ENE KB930 Embedded Controller attached to an
+  I2C bus.
+
+maintainers:
+  - Dmitry Osipenko <digetx@gmail.com>
+
+properties:
+  compatible:
+    items:
+      - enum:
+        - acer,a500-iconia-ec # Acer A500 Iconia tablet device
+      - enum:
+        - ene,kb930
+  reg:
+    maxItems: 1
+
+  monitored-battery: true
+  power-supplies: true
+  system-power-controller: true
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    battery: battery-cell {
+      compatible = "simple-battery";
+      charge-full-design-microamp-hours = <3260000>;
+      energy-full-design-microwatt-hours = <24000000>;
+      operating-range-celsius = <0 40>;
+    };
+
+    mains: ac-adapter {
+      compatible = "gpio-charger";
+      charger-type = "mains";
+      gpios = <&gpio 125 0>;
+    };
+
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      embedded-controller@58 {
+        compatible = "acer,a500-iconia-ec", "ene,kb930";
+        reg = <0x58>;
+
+        system-power-controller;
+
+        monitored-battery = <&battery>;
+        power-supplies = <&mains>;
+      };
+    };
+
+...
-- 
2.27.0

Re: [PATCH v3 1/5] dt-bindings: mfd: Add ENE KB930 Embedded Controller binding

[Rob Herring]

On Sun, 06 Sep 2020 22:50:59 +0300, Dmitry Osipenko wrote:
> Add binding document for the ENE KB930 Embedded Controller.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  .../devicetree/bindings/mfd/ene-kb930.yaml    | 66 +++++++++++++++++++
>  1 file changed, 66 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mfd/ene-kb930.yaml
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v3 1/5] dt-bindings: mfd: Add ENE KB930 Embedded Controller binding

[Sebastian Reichel]

[-- Attachment #1: Type: text/plain, Size: 2470 bytes --]

Hi,

On Sun, Sep 06, 2020 at 10:50:59PM +0300, Dmitry Osipenko wrote:
> Add binding document for the ENE KB930 Embedded Controller.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  .../devicetree/bindings/mfd/ene-kb930.yaml    | 66 +++++++++++++++++++
>  1 file changed, 66 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mfd/ene-kb930.yaml
> 
> diff --git a/Documentation/devicetree/bindings/mfd/ene-kb930.yaml b/Documentation/devicetree/bindings/mfd/ene-kb930.yaml
> new file mode 100644
> index 000000000000..635c8966ca22
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/ene-kb930.yaml
> @@ -0,0 +1,66 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/mfd/ene-kb930.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: ENE KB930 Embedded Controller bindings
> +
> +description: |
> +  This binding describes the ENE KB930 Embedded Controller attached to an
> +  I2C bus.
> +
> +maintainers:
> +  - Dmitry Osipenko <digetx@gmail.com>
> +
> +properties:
> +  compatible:
> +    items:
> +      - enum:
> +        - acer,a500-iconia-ec # Acer A500 Iconia tablet device
> +      - enum:
> +        - ene,kb930
> +  reg:
> +    maxItems: 1
> +
> +  monitored-battery: true

^^^ this is not being used by your battery driver. Do you plan
to use it in the future or is it a copy&paste mistake? :)

-- Sebastian

> +  power-supplies: true
> +  system-power-controller: true
> +
> +required:
> +  - compatible
> +  - reg
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    battery: battery-cell {
> +      compatible = "simple-battery";
> +      charge-full-design-microamp-hours = <3260000>;
> +      energy-full-design-microwatt-hours = <24000000>;
> +      operating-range-celsius = <0 40>;
> +    };
> +
> +    mains: ac-adapter {
> +      compatible = "gpio-charger";
> +      charger-type = "mains";
> +      gpios = <&gpio 125 0>;
> +    };
> +
> +    i2c {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      embedded-controller@58 {
> +        compatible = "acer,a500-iconia-ec", "ene,kb930";
> +        reg = <0x58>;
> +
> +        system-power-controller;
> +
> +        monitored-battery = <&battery>;
> +        power-supplies = <&mains>;
> +      };
> +    };
> +
> +...
> -- 
> 2.27.0
> 

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Re: [PATCH v3 1/5] dt-bindings: mfd: Add ENE KB930 Embedded Controller binding

[Dmitry Osipenko]

09.10.2020 02:00, Sebastian Reichel пишет:
> Hi,
> 
> On Sun, Sep 06, 2020 at 10:50:59PM +0300, Dmitry Osipenko wrote:
>> Add binding document for the ENE KB930 Embedded Controller.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>> ---
>>  .../devicetree/bindings/mfd/ene-kb930.yaml    | 66 +++++++++++++++++++
>>  1 file changed, 66 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/mfd/ene-kb930.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/mfd/ene-kb930.yaml b/Documentation/devicetree/bindings/mfd/ene-kb930.yaml
>> new file mode 100644
>> index 000000000000..635c8966ca22
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/mfd/ene-kb930.yaml
>> @@ -0,0 +1,66 @@
>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/mfd/ene-kb930.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: ENE KB930 Embedded Controller bindings
>> +
>> +description: |
>> +  This binding describes the ENE KB930 Embedded Controller attached to an
>> +  I2C bus.
>> +
>> +maintainers:
>> +  - Dmitry Osipenko <digetx@gmail.com>
>> +
>> +properties:
>> +  compatible:
>> +    items:
>> +      - enum:
>> +        - acer,a500-iconia-ec # Acer A500 Iconia tablet device
>> +      - enum:
>> +        - ene,kb930
>> +  reg:
>> +    maxItems: 1
>> +
>> +  monitored-battery: true
> 
> ^^^ this is not being used by your battery driver. Do you plan
> to use it in the future or is it a copy&paste mistake? :)

Hello, this is correct that driver doesn't use monitored-battery info,
but I was thinking that it's good to have anyways in the device-tree
because this completes hardware description + the gauge driver isn't
aware about maximal battery temperature. Hence it may become useful and
it doesn't hurt to have that additional information about battery cell.

[PATCH v3 2/5] mfd: Add driver for Embedded Controller found on Acer Iconia Tab A500

[Dmitry Osipenko]

Acer Iconia Tab A500 is an Android tablet device, it has ENE KB930
Embedded Controller which provides battery-gauge, LED, GPIO and some
other functions. The EC uses firmware that is specifically customized
for Acer A500. This patch adds MFD driver for the Embedded Controller
which allows to power-off / reboot the A500 device, it also provides
a common register read/write API that will be used by the sub-devices.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/mfd/Kconfig        |  12 +++
 drivers/mfd/Makefile       |   1 +
 drivers/mfd/acer-ec-a500.c | 203 +++++++++++++++++++++++++++++++++++++
 3 files changed, 216 insertions(+)
 create mode 100644 drivers/mfd/acer-ec-a500.c

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 231095933778..9b10e5895136 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -2062,6 +2062,18 @@ config MFD_KHADAS_MCU
 	  additional drivers must be enabled in order to use the functionality
 	  of the device.
 
+config MFD_ACER_A500_EC
+	tristate "Embedded Controller driver for Acer Iconia Tab A500"
+	depends on I2C
+	depends on ARCH_TEGRA_2x_SOC || COMPILE_TEST
+	select MFD_CORE
+	select REGMAP
+	help
+	  Support for Acer Iconia Tab A500 Embedded Controller.
+
+	  The controller itself is ENE KB930, it is running firmware
+	  customized for the specific needs of the Acer A500 hardware.
+
 menu "Multimedia Capabilities Port drivers"
 	depends on ARCH_SA1100
 
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index a60e5f835283..6e3a6162ad94 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -262,5 +262,6 @@ obj-$(CONFIG_MFD_ROHM_BD71828)	+= rohm-bd71828.o
 obj-$(CONFIG_MFD_ROHM_BD718XX)	+= rohm-bd718x7.o
 obj-$(CONFIG_MFD_STMFX) 	+= stmfx.o
 obj-$(CONFIG_MFD_KHADAS_MCU) 	+= khadas-mcu.o
+obj-$(CONFIG_MFD_ACER_A500_EC)	+= acer-ec-a500.o
 
 obj-$(CONFIG_SGI_MFD_IOC3)	+= ioc3.o
diff --git a/drivers/mfd/acer-ec-a500.c b/drivers/mfd/acer-ec-a500.c
new file mode 100644
index 000000000000..2785a6d9bcc4
--- /dev/null
+++ b/drivers/mfd/acer-ec-a500.c
@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * MFD driver for Acer Iconia Tab A500 Embedded Controller.
+ *
+ * Copyright 2020 GRATE-driver project.
+ *
+ * Based on downstream driver from Acer Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/reboot.h>
+
+#define A500_EC_I2C_ERR_TIMEOUT		500
+#define A500_EC_POWER_CMD_TIMEOUT	1000
+
+enum {
+	REG_CURRENT_NOW = 0x03,
+	REG_SHUTDOWN = 0x52,
+	REG_WARM_REBOOT = 0x54,
+	REG_COLD_REBOOT = 0x55,
+};
+
+static struct i2c_client *a500_ec_client_pm_off;
+
+static int a500_ec_read(void *context, const void *reg_buf, size_t reg_size,
+			void *val_buf, size_t val_sizel)
+{
+	struct i2c_client *client = context;
+	unsigned int reg, retries = 5;
+	u16 *ret_val = val_buf;
+	s32 ret = 0;
+
+	if (reg_size != 1 || val_sizel != 2)
+		return -EOPNOTSUPP;
+
+	reg = *(u8 *)reg_buf;
+
+	while (retries-- > 0) {
+		ret = i2c_smbus_read_word_data(client, reg);
+		if (ret >= 0)
+			break;
+
+		msleep(A500_EC_I2C_ERR_TIMEOUT);
+	}
+
+	if (ret < 0) {
+		dev_err(&client->dev, "read 0x%x failed: %d\n", reg, ret);
+		return ret;
+	}
+
+	*ret_val = ret;
+
+	if (reg == REG_CURRENT_NOW)
+		fsleep(10000);
+
+	return 0;
+}
+
+static int a500_ec_write(void *context, const void *data, size_t count)
+{
+	struct i2c_client *client = context;
+	unsigned int reg, val, retries = 5;
+	s32 ret = 0;
+
+	if (count != 3)
+		return -EOPNOTSUPP;
+
+	reg = *(u8  *)(data + 0);
+	val = *(u16 *)(data + 1);
+
+	while (retries-- > 0) {
+		ret = i2c_smbus_write_word_data(client, reg, val);
+		if (ret >= 0)
+			break;
+
+		msleep(A500_EC_I2C_ERR_TIMEOUT);
+	}
+
+	if (ret < 0) {
+		dev_err(&client->dev, "write 0x%x failed: %d\n", reg, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct regmap_config a500_ec_regmap_config = {
+	.name = "KB930",
+	.reg_bits = 8,
+	.val_bits = 16,
+	.max_register = 0xff,
+};
+
+static const struct regmap_bus a500_ec_regmap_bus = {
+	.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
+	.val_format_endian_default = REGMAP_ENDIAN_LITTLE,
+	.write = a500_ec_write,
+	.read = a500_ec_read,
+	.max_raw_read = 2,
+};
+
+static void a500_ec_poweroff(void)
+{
+	i2c_smbus_write_word_data(a500_ec_client_pm_off, REG_SHUTDOWN, 0);
+
+	mdelay(A500_EC_POWER_CMD_TIMEOUT);
+}
+
+static int a500_ec_restart_notify(struct notifier_block *this,
+				  unsigned long reboot_mode, void *data)
+{
+	if (reboot_mode == REBOOT_WARM)
+		i2c_smbus_write_word_data(a500_ec_client_pm_off,
+					  REG_WARM_REBOOT, 0);
+	else
+		i2c_smbus_write_word_data(a500_ec_client_pm_off,
+					  REG_COLD_REBOOT, 1);
+
+	mdelay(A500_EC_POWER_CMD_TIMEOUT);
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block a500_ec_restart_handler = {
+	.notifier_call = a500_ec_restart_notify,
+	.priority = 200,
+};
+
+static const struct mfd_cell a500_ec_cells[] = {
+	{ .name = "acer-a500-iconia-battery", },
+	{ .name = "acer-a500-iconia-leds", },
+};
+
+static int a500_ec_probe(struct i2c_client *client)
+{
+	struct regmap *rmap;
+	int err;
+
+	rmap = devm_regmap_init(&client->dev, &a500_ec_regmap_bus,
+				client, &a500_ec_regmap_config);
+	if (IS_ERR(rmap))
+		return PTR_ERR(rmap);
+
+	/* register battery and LED sub-devices */
+	err = devm_mfd_add_devices(&client->dev, PLATFORM_DEVID_AUTO,
+				   a500_ec_cells, ARRAY_SIZE(a500_ec_cells),
+				   NULL, 0, NULL);
+	if (err) {
+		dev_err(&client->dev, "failed to add sub-devices: %d\n", err);
+		return err;
+	}
+
+	/* set up power management functions */
+	if (of_device_is_system_power_controller(client->dev.of_node)) {
+		a500_ec_client_pm_off = client;
+
+		err = register_restart_handler(&a500_ec_restart_handler);
+		if (err)
+			return err;
+
+		if (!pm_power_off)
+			pm_power_off = a500_ec_poweroff;
+	}
+
+	return 0;
+}
+
+static int a500_ec_remove(struct i2c_client *client)
+{
+	if (of_device_is_system_power_controller(client->dev.of_node)) {
+		if (pm_power_off == a500_ec_poweroff)
+			pm_power_off = NULL;
+
+		unregister_restart_handler(&a500_ec_restart_handler);
+	}
+
+	return 0;
+}
+
+static const struct of_device_id a500_ec_match[] = {
+	{ .compatible = "acer,a500-iconia-ec" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, a500_ec_match);
+
+static struct i2c_driver a500_ec_driver = {
+	.driver = {
+		.name = "acer-a500-embedded-controller",
+		.of_match_table = a500_ec_match,
+	},
+	.probe_new = a500_ec_probe,
+	.remove = a500_ec_remove,
+};
+module_i2c_driver(a500_ec_driver);
+
+MODULE_DESCRIPTION("Acer Iconia Tab A500 Embedded Controller driver");
+MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
+MODULE_LICENSE("GPL");
-- 
2.27.0

[PATCH v3 3/5] power: supply: Add battery gauge driver for Acer Iconia Tab A500

[Dmitry Osipenko]

This patch adds battery gauge driver for Acer Iconia Tab A500 device.
The battery gauge function is provided via the Embedded Controller,
which is found on the Acer A500.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/power/supply/Kconfig             |   6 +
 drivers/power/supply/Makefile            |   1 +
 drivers/power/supply/acer_a500_battery.c | 297 +++++++++++++++++++++++
 3 files changed, 304 insertions(+)
 create mode 100644 drivers/power/supply/acer_a500_battery.c

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index a4657484f38b..21257a81b55b 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -760,4 +760,10 @@ config RN5T618_POWER
 	  This driver can also be built as a module. If so, the module will be
 	  called rn5t618_power.
 
+config BATTERY_ACER_A500
+	tristate "Acer Iconia Tab A500 battery driver"
+	depends on MFD_ACER_A500_EC
+	help
+	  Say Y to include support for Acer Iconia Tab A500 battery fuel gauge.
+
 endif # POWER_SUPPLY
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index 293d4a5d80d3..d0f1b77c5c49 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -97,3 +97,4 @@ obj-$(CONFIG_CHARGER_BD70528)	+= bd70528-charger.o
 obj-$(CONFIG_CHARGER_BD99954)	+= bd99954-charger.o
 obj-$(CONFIG_CHARGER_WILCO)	+= wilco-charger.o
 obj-$(CONFIG_RN5T618_POWER)	+= rn5t618_power.o
+obj-$(CONFIG_BATTERY_ACER_A500)	+= acer_a500_battery.o
diff --git a/drivers/power/supply/acer_a500_battery.c b/drivers/power/supply/acer_a500_battery.c
new file mode 100644
index 000000000000..93135933c8af
--- /dev/null
+++ b/drivers/power/supply/acer_a500_battery.c
@@ -0,0 +1,297 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Battery driver for Acer Iconia Tab A500.
+ *
+ * Copyright 2020 GRATE-driver project.
+ *
+ * Based on downstream driver from Acer Inc.
+ * Based on NVIDIA Gas Gauge driver for SBS Compliant Batteries.
+ *
+ * Copyright (c) 2010, NVIDIA Corporation.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/regmap.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+enum {
+	REG_CAPACITY,
+	REG_VOLTAGE,
+	REG_CURRENT,
+	REG_DESIGN_CAPACITY,
+	REG_TEMPERATURE,
+};
+
+#define EC_DATA(_reg, _psp) {			\
+	.psp = POWER_SUPPLY_PROP_ ## _psp,	\
+	.reg = _reg,				\
+}
+
+static const struct battery_register {
+	enum power_supply_property psp;
+	unsigned int reg;
+} ec_data[] = {
+	[REG_CAPACITY]		= EC_DATA(0x00, CAPACITY),
+	[REG_VOLTAGE]		= EC_DATA(0x01, VOLTAGE_NOW),
+	[REG_CURRENT]		= EC_DATA(0x03, CURRENT_NOW),
+	[REG_DESIGN_CAPACITY]	= EC_DATA(0x08, CHARGE_FULL_DESIGN),
+	[REG_TEMPERATURE]	= EC_DATA(0x0a, TEMP),
+};
+
+static const enum power_supply_property a500_battery_properties[] = {
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
+	POWER_SUPPLY_PROP_CURRENT_NOW,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_TECHNOLOGY,
+	POWER_SUPPLY_PROP_TEMP,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+};
+
+struct a500_battery {
+	struct delayed_work poll_work;
+	struct power_supply *psy;
+	struct regmap *rmap;
+	unsigned int capacity;
+};
+
+static bool a500_battery_update_capacity(struct a500_battery *bat)
+{
+	unsigned int capacity;
+	int err;
+
+	err = regmap_read(bat->rmap, ec_data[REG_CAPACITY].reg, &capacity);
+	if (err)
+		return false;
+
+	/* capacity can be >100% even if max value is 100% */
+	capacity = min(capacity, 100u);
+
+	if (bat->capacity != capacity) {
+		bat->capacity = capacity;
+		return true;
+	}
+
+	return false;
+}
+
+static int a500_battery_get_status(struct a500_battery *bat)
+{
+	if (bat->capacity < 100) {
+		if (power_supply_am_i_supplied(bat->psy))
+			return POWER_SUPPLY_STATUS_CHARGING;
+		else
+			return POWER_SUPPLY_STATUS_DISCHARGING;
+	}
+
+	return POWER_SUPPLY_STATUS_FULL;
+}
+
+static void a500_battery_unit_adjustment(struct device *dev,
+					 enum power_supply_property psp,
+					 union power_supply_propval *val)
+{
+	const unsigned int base_unit_conversion = 1000;
+	const unsigned int temp_kelvin_to_celsius = 2731;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
+	case POWER_SUPPLY_PROP_CURRENT_NOW:
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		val->intval *= base_unit_conversion;
+		break;
+
+	case POWER_SUPPLY_PROP_TEMP:
+		val->intval -= temp_kelvin_to_celsius;
+		break;
+
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = !!val->intval;
+		break;
+
+	default:
+		dev_dbg(dev,
+			"%s: no need for unit conversion %d\n", __func__, psp);
+	}
+}
+
+static int a500_battery_get_ec_data_index(struct device *dev,
+					  enum power_supply_property psp)
+{
+	unsigned int i;
+
+	/*
+	 * DESIGN_CAPACITY register always returns a non-zero value if
+	 * battery is connected and zero if disconnected, hence we'll use
+	 * it for judging the battery presence.
+	 */
+	if (psp == POWER_SUPPLY_PROP_PRESENT)
+		psp = POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN;
+
+	for (i = 0; i < ARRAY_SIZE(ec_data); i++)
+		if (psp == ec_data[i].psp)
+			return i;
+
+	dev_dbg(dev, "%s: invalid property %u\n", __func__, psp);
+
+	return -EINVAL;
+}
+
+static int a500_battery_get_property(struct power_supply *psy,
+				     enum power_supply_property psp,
+				     union power_supply_propval *val)
+{
+	struct a500_battery *bat = power_supply_get_drvdata(psy);
+	struct device *dev = psy->dev.parent;
+	int ret = 0;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		val->intval = a500_battery_get_status(bat);
+		break;
+
+	case POWER_SUPPLY_PROP_TECHNOLOGY:
+		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
+		break;
+
+	case POWER_SUPPLY_PROP_CAPACITY:
+		a500_battery_update_capacity(bat);
+		val->intval = bat->capacity;
+		break;
+
+	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
+	case POWER_SUPPLY_PROP_CURRENT_NOW:
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+	case POWER_SUPPLY_PROP_PRESENT:
+	case POWER_SUPPLY_PROP_TEMP:
+		ret = a500_battery_get_ec_data_index(dev, psp);
+		if (ret < 0)
+			break;
+
+		ret = regmap_read(bat->rmap, ec_data[ret].reg, &val->intval);
+		break;
+
+	default:
+		dev_err(dev, "%s: invalid property %u\n", __func__, psp);
+		return -EINVAL;
+	}
+
+	if (!ret) {
+		/* convert units to match requirements of power supply class */
+		a500_battery_unit_adjustment(dev, psp, val);
+	}
+
+	dev_dbg(dev, "%s: property = %d, value = %x\n",
+		__func__, psp, val->intval);
+
+	/* return NODATA for properties if battery not presents */
+	if (ret)
+		return -ENODATA;
+
+	return 0;
+}
+
+static void a500_battery_poll_work(struct work_struct *work)
+{
+	struct a500_battery *bat;
+	bool capacity_changed;
+
+	bat = container_of(work, struct a500_battery, poll_work.work);
+	capacity_changed = a500_battery_update_capacity(bat);
+
+	if (capacity_changed)
+		power_supply_changed(bat->psy);
+
+	/* continuously send uevent notification */
+	schedule_delayed_work(&bat->poll_work, 30 * HZ);
+}
+
+static const struct power_supply_desc a500_battery_desc = {
+	.name = "ec-battery",
+	.type = POWER_SUPPLY_TYPE_BATTERY,
+	.properties = a500_battery_properties,
+	.get_property = a500_battery_get_property,
+	.num_properties = ARRAY_SIZE(a500_battery_properties),
+	.external_power_changed = power_supply_changed,
+};
+
+static int a500_battery_probe(struct platform_device *pdev)
+{
+	struct power_supply_config psy_cfg = {};
+	struct a500_battery *bat;
+
+	bat = devm_kzalloc(&pdev->dev, sizeof(*bat), GFP_KERNEL);
+	if (!bat)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, bat);
+
+	psy_cfg.of_node = pdev->dev.parent->of_node;
+	psy_cfg.drv_data = bat;
+
+	bat->rmap = dev_get_regmap(pdev->dev.parent, "KB930");
+	if (!bat->rmap)
+		return -EINVAL;
+
+	bat->psy = devm_power_supply_register_no_ws(&pdev->dev,
+						    &a500_battery_desc,
+						    &psy_cfg);
+	if (IS_ERR(bat->psy))
+		return dev_err_probe(&pdev->dev, PTR_ERR(bat->psy),
+				     "failed to register battery\n");
+
+	INIT_DELAYED_WORK(&bat->poll_work, a500_battery_poll_work);
+	schedule_delayed_work(&bat->poll_work, HZ);
+
+	return 0;
+}
+
+static int a500_battery_remove(struct platform_device *pdev)
+{
+	struct a500_battery *bat = dev_get_drvdata(&pdev->dev);
+
+	cancel_delayed_work_sync(&bat->poll_work);
+
+	return 0;
+}
+
+static int __maybe_unused a500_battery_suspend(struct device *dev)
+{
+	struct a500_battery *bat = dev_get_drvdata(dev);
+
+	cancel_delayed_work_sync(&bat->poll_work);
+
+	return 0;
+}
+
+static int __maybe_unused a500_battery_resume(struct device *dev)
+{
+	struct a500_battery *bat = dev_get_drvdata(dev);
+
+	schedule_delayed_work(&bat->poll_work, HZ);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(a500_battery_pm_ops,
+			 a500_battery_suspend, a500_battery_resume);
+
+static struct platform_driver a500_battery_driver = {
+	.driver = {
+		.name = "acer-a500-iconia-battery",
+		.pm = &a500_battery_pm_ops,
+	},
+	.probe = a500_battery_probe,
+	.remove = a500_battery_remove,
+};
+module_platform_driver(a500_battery_driver);
+
+MODULE_DESCRIPTION("Battery gauge driver for Acer Iconia Tab A500");
+MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
+MODULE_ALIAS("platform:acer-a500-iconia-battery");
+MODULE_LICENSE("GPL");
-- 
2.27.0

Re: [PATCH v3 3/5] power: supply: Add battery gauge driver for Acer Iconia Tab A500

[Sebastian Reichel]

[-- Attachment #1: Type: text/plain, Size: 10425 bytes --]

Hi,

On Sun, Sep 06, 2020 at 10:51:01PM +0300, Dmitry Osipenko wrote:
> This patch adds battery gauge driver for Acer Iconia Tab A500 device.
> The battery gauge function is provided via the Embedded Controller,
> which is found on the Acer A500.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---

Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>

-- Sebastian

>  drivers/power/supply/Kconfig             |   6 +
>  drivers/power/supply/Makefile            |   1 +
>  drivers/power/supply/acer_a500_battery.c | 297 +++++++++++++++++++++++
>  3 files changed, 304 insertions(+)
>  create mode 100644 drivers/power/supply/acer_a500_battery.c
> 
> diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
> index a4657484f38b..21257a81b55b 100644
> --- a/drivers/power/supply/Kconfig
> +++ b/drivers/power/supply/Kconfig
> @@ -760,4 +760,10 @@ config RN5T618_POWER
>  	  This driver can also be built as a module. If so, the module will be
>  	  called rn5t618_power.
>  
> +config BATTERY_ACER_A500
> +	tristate "Acer Iconia Tab A500 battery driver"
> +	depends on MFD_ACER_A500_EC
> +	help
> +	  Say Y to include support for Acer Iconia Tab A500 battery fuel gauge.
> +
>  endif # POWER_SUPPLY
> diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
> index 293d4a5d80d3..d0f1b77c5c49 100644
> --- a/drivers/power/supply/Makefile
> +++ b/drivers/power/supply/Makefile
> @@ -97,3 +97,4 @@ obj-$(CONFIG_CHARGER_BD70528)	+= bd70528-charger.o
>  obj-$(CONFIG_CHARGER_BD99954)	+= bd99954-charger.o
>  obj-$(CONFIG_CHARGER_WILCO)	+= wilco-charger.o
>  obj-$(CONFIG_RN5T618_POWER)	+= rn5t618_power.o
> +obj-$(CONFIG_BATTERY_ACER_A500)	+= acer_a500_battery.o
> diff --git a/drivers/power/supply/acer_a500_battery.c b/drivers/power/supply/acer_a500_battery.c
> new file mode 100644
> index 000000000000..93135933c8af
> --- /dev/null
> +++ b/drivers/power/supply/acer_a500_battery.c
> @@ -0,0 +1,297 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Battery driver for Acer Iconia Tab A500.
> + *
> + * Copyright 2020 GRATE-driver project.
> + *
> + * Based on downstream driver from Acer Inc.
> + * Based on NVIDIA Gas Gauge driver for SBS Compliant Batteries.
> + *
> + * Copyright (c) 2010, NVIDIA Corporation.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/power_supply.h>
> +#include <linux/regmap.h>
> +#include <linux/sched.h>
> +#include <linux/slab.h>
> +#include <linux/workqueue.h>
> +
> +enum {
> +	REG_CAPACITY,
> +	REG_VOLTAGE,
> +	REG_CURRENT,
> +	REG_DESIGN_CAPACITY,
> +	REG_TEMPERATURE,
> +};
> +
> +#define EC_DATA(_reg, _psp) {			\
> +	.psp = POWER_SUPPLY_PROP_ ## _psp,	\
> +	.reg = _reg,				\
> +}
> +
> +static const struct battery_register {
> +	enum power_supply_property psp;
> +	unsigned int reg;
> +} ec_data[] = {
> +	[REG_CAPACITY]		= EC_DATA(0x00, CAPACITY),
> +	[REG_VOLTAGE]		= EC_DATA(0x01, VOLTAGE_NOW),
> +	[REG_CURRENT]		= EC_DATA(0x03, CURRENT_NOW),
> +	[REG_DESIGN_CAPACITY]	= EC_DATA(0x08, CHARGE_FULL_DESIGN),
> +	[REG_TEMPERATURE]	= EC_DATA(0x0a, TEMP),
> +};
> +
> +static const enum power_supply_property a500_battery_properties[] = {
> +	POWER_SUPPLY_PROP_CAPACITY,
> +	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
> +	POWER_SUPPLY_PROP_CURRENT_NOW,
> +	POWER_SUPPLY_PROP_PRESENT,
> +	POWER_SUPPLY_PROP_STATUS,
> +	POWER_SUPPLY_PROP_TECHNOLOGY,
> +	POWER_SUPPLY_PROP_TEMP,
> +	POWER_SUPPLY_PROP_VOLTAGE_NOW,
> +};
> +
> +struct a500_battery {
> +	struct delayed_work poll_work;
> +	struct power_supply *psy;
> +	struct regmap *rmap;
> +	unsigned int capacity;
> +};
> +
> +static bool a500_battery_update_capacity(struct a500_battery *bat)
> +{
> +	unsigned int capacity;
> +	int err;
> +
> +	err = regmap_read(bat->rmap, ec_data[REG_CAPACITY].reg, &capacity);
> +	if (err)
> +		return false;
> +
> +	/* capacity can be >100% even if max value is 100% */
> +	capacity = min(capacity, 100u);
> +
> +	if (bat->capacity != capacity) {
> +		bat->capacity = capacity;
> +		return true;
> +	}
> +
> +	return false;
> +}
> +
> +static int a500_battery_get_status(struct a500_battery *bat)
> +{
> +	if (bat->capacity < 100) {
> +		if (power_supply_am_i_supplied(bat->psy))
> +			return POWER_SUPPLY_STATUS_CHARGING;
> +		else
> +			return POWER_SUPPLY_STATUS_DISCHARGING;
> +	}
> +
> +	return POWER_SUPPLY_STATUS_FULL;
> +}
> +
> +static void a500_battery_unit_adjustment(struct device *dev,
> +					 enum power_supply_property psp,
> +					 union power_supply_propval *val)
> +{
> +	const unsigned int base_unit_conversion = 1000;
> +	const unsigned int temp_kelvin_to_celsius = 2731;
> +
> +	switch (psp) {
> +	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
> +	case POWER_SUPPLY_PROP_CURRENT_NOW:
> +	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
> +		val->intval *= base_unit_conversion;
> +		break;
> +
> +	case POWER_SUPPLY_PROP_TEMP:
> +		val->intval -= temp_kelvin_to_celsius;
> +		break;
> +
> +	case POWER_SUPPLY_PROP_PRESENT:
> +		val->intval = !!val->intval;
> +		break;
> +
> +	default:
> +		dev_dbg(dev,
> +			"%s: no need for unit conversion %d\n", __func__, psp);
> +	}
> +}
> +
> +static int a500_battery_get_ec_data_index(struct device *dev,
> +					  enum power_supply_property psp)
> +{
> +	unsigned int i;
> +
> +	/*
> +	 * DESIGN_CAPACITY register always returns a non-zero value if
> +	 * battery is connected and zero if disconnected, hence we'll use
> +	 * it for judging the battery presence.
> +	 */
> +	if (psp == POWER_SUPPLY_PROP_PRESENT)
> +		psp = POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN;
> +
> +	for (i = 0; i < ARRAY_SIZE(ec_data); i++)
> +		if (psp == ec_data[i].psp)
> +			return i;
> +
> +	dev_dbg(dev, "%s: invalid property %u\n", __func__, psp);
> +
> +	return -EINVAL;
> +}
> +
> +static int a500_battery_get_property(struct power_supply *psy,
> +				     enum power_supply_property psp,
> +				     union power_supply_propval *val)
> +{
> +	struct a500_battery *bat = power_supply_get_drvdata(psy);
> +	struct device *dev = psy->dev.parent;
> +	int ret = 0;
> +
> +	switch (psp) {
> +	case POWER_SUPPLY_PROP_STATUS:
> +		val->intval = a500_battery_get_status(bat);
> +		break;
> +
> +	case POWER_SUPPLY_PROP_TECHNOLOGY:
> +		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
> +		break;
> +
> +	case POWER_SUPPLY_PROP_CAPACITY:
> +		a500_battery_update_capacity(bat);
> +		val->intval = bat->capacity;
> +		break;
> +
> +	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
> +	case POWER_SUPPLY_PROP_CURRENT_NOW:
> +	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
> +	case POWER_SUPPLY_PROP_PRESENT:
> +	case POWER_SUPPLY_PROP_TEMP:
> +		ret = a500_battery_get_ec_data_index(dev, psp);
> +		if (ret < 0)
> +			break;
> +
> +		ret = regmap_read(bat->rmap, ec_data[ret].reg, &val->intval);
> +		break;
> +
> +	default:
> +		dev_err(dev, "%s: invalid property %u\n", __func__, psp);
> +		return -EINVAL;
> +	}
> +
> +	if (!ret) {
> +		/* convert units to match requirements of power supply class */
> +		a500_battery_unit_adjustment(dev, psp, val);
> +	}
> +
> +	dev_dbg(dev, "%s: property = %d, value = %x\n",
> +		__func__, psp, val->intval);
> +
> +	/* return NODATA for properties if battery not presents */
> +	if (ret)
> +		return -ENODATA;
> +
> +	return 0;
> +}
> +
> +static void a500_battery_poll_work(struct work_struct *work)
> +{
> +	struct a500_battery *bat;
> +	bool capacity_changed;
> +
> +	bat = container_of(work, struct a500_battery, poll_work.work);
> +	capacity_changed = a500_battery_update_capacity(bat);
> +
> +	if (capacity_changed)
> +		power_supply_changed(bat->psy);
> +
> +	/* continuously send uevent notification */
> +	schedule_delayed_work(&bat->poll_work, 30 * HZ);
> +}
> +
> +static const struct power_supply_desc a500_battery_desc = {
> +	.name = "ec-battery",
> +	.type = POWER_SUPPLY_TYPE_BATTERY,
> +	.properties = a500_battery_properties,
> +	.get_property = a500_battery_get_property,
> +	.num_properties = ARRAY_SIZE(a500_battery_properties),
> +	.external_power_changed = power_supply_changed,
> +};
> +
> +static int a500_battery_probe(struct platform_device *pdev)
> +{
> +	struct power_supply_config psy_cfg = {};
> +	struct a500_battery *bat;
> +
> +	bat = devm_kzalloc(&pdev->dev, sizeof(*bat), GFP_KERNEL);
> +	if (!bat)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, bat);
> +
> +	psy_cfg.of_node = pdev->dev.parent->of_node;
> +	psy_cfg.drv_data = bat;
> +
> +	bat->rmap = dev_get_regmap(pdev->dev.parent, "KB930");
> +	if (!bat->rmap)
> +		return -EINVAL;
> +
> +	bat->psy = devm_power_supply_register_no_ws(&pdev->dev,
> +						    &a500_battery_desc,
> +						    &psy_cfg);
> +	if (IS_ERR(bat->psy))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(bat->psy),
> +				     "failed to register battery\n");
> +
> +	INIT_DELAYED_WORK(&bat->poll_work, a500_battery_poll_work);
> +	schedule_delayed_work(&bat->poll_work, HZ);
> +
> +	return 0;
> +}
> +
> +static int a500_battery_remove(struct platform_device *pdev)
> +{
> +	struct a500_battery *bat = dev_get_drvdata(&pdev->dev);
> +
> +	cancel_delayed_work_sync(&bat->poll_work);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused a500_battery_suspend(struct device *dev)
> +{
> +	struct a500_battery *bat = dev_get_drvdata(dev);
> +
> +	cancel_delayed_work_sync(&bat->poll_work);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused a500_battery_resume(struct device *dev)
> +{
> +	struct a500_battery *bat = dev_get_drvdata(dev);
> +
> +	schedule_delayed_work(&bat->poll_work, HZ);
> +
> +	return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(a500_battery_pm_ops,
> +			 a500_battery_suspend, a500_battery_resume);
> +
> +static struct platform_driver a500_battery_driver = {
> +	.driver = {
> +		.name = "acer-a500-iconia-battery",
> +		.pm = &a500_battery_pm_ops,
> +	},
> +	.probe = a500_battery_probe,
> +	.remove = a500_battery_remove,
> +};
> +module_platform_driver(a500_battery_driver);
> +
> +MODULE_DESCRIPTION("Battery gauge driver for Acer Iconia Tab A500");
> +MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
> +MODULE_ALIAS("platform:acer-a500-iconia-battery");
> +MODULE_LICENSE("GPL");
> -- 
> 2.27.0
> 

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[PATCH v3 4/5] leds: Add driver for Acer Iconia Tab A500

[Dmitry Osipenko]

Acer Iconia Tab A500 is an Android tablet device which has two LEDs
embedded into the Power Button. Orange LED indicates "battery charging"
status and white LED indicates "wake-up/charge-done" status. The new LED
driver provides control over both LEDs to userspace.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/leds/Kconfig          |   7 ++
 drivers/leds/Makefile         |   1 +
 drivers/leds/leds-acer-a500.c | 129 ++++++++++++++++++++++++++++++++++
 3 files changed, 137 insertions(+)
 create mode 100644 drivers/leds/leds-acer-a500.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 4f6464a169d5..4c39b53bcf1f 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -921,6 +921,13 @@ config LEDS_SGM3140
 	  This option enables support for the SGM3140 500mA Buck/Boost Charge
 	  Pump LED Driver.
 
+config LEDS_ACER_A500
+	tristate "Power button LED support for Acer Iconia Tab A500"
+	depends on LEDS_CLASS && MFD_ACER_A500_EC
+	help
+	  This option enables support for the Power Button LED of
+	  Acer Iconia Tab A500.
+
 comment "LED Triggers"
 source "drivers/leds/trigger/Kconfig"
 
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 778cb4bb8c52..73e603e1727e 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_LEDS_TRIGGERS)		+= led-triggers.o
 # LED Platform Drivers (keep this sorted, M-| sort)
 obj-$(CONFIG_LEDS_88PM860X)		+= leds-88pm860x.o
 obj-$(CONFIG_LEDS_AAT1290)		+= leds-aat1290.o
+obj-$(CONFIG_LEDS_ACER_A500)		+= leds-acer-a500.o
 obj-$(CONFIG_LEDS_ADP5520)		+= leds-adp5520.o
 obj-$(CONFIG_LEDS_AN30259A)		+= leds-an30259a.o
 obj-$(CONFIG_LEDS_APU)			+= leds-apu.o
diff --git a/drivers/leds/leds-acer-a500.c b/drivers/leds/leds-acer-a500.c
new file mode 100644
index 000000000000..8cf0b11f4390
--- /dev/null
+++ b/drivers/leds/leds-acer-a500.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define A500_EC_LED_DELAY_USEC	(100 * 1000)
+
+enum {
+	REG_RESET_LEDS = 0x40,
+	REG_POWER_LED_ON = 0x42,
+	REG_CHARGE_LED_ON = 0x43,
+	REG_ANDROID_LEDS_OFF = 0x5a,
+};
+
+struct a500_led {
+	struct led_classdev cdev;
+	const struct reg_sequence *enable_seq;
+	struct a500_led *other;
+	struct regmap *rmap;
+};
+
+static const struct reg_sequence a500_ec_leds_reset_seq[] = {
+	REG_SEQ(REG_RESET_LEDS, 0x0, A500_EC_LED_DELAY_USEC),
+	REG_SEQ(REG_ANDROID_LEDS_OFF, 0x0, A500_EC_LED_DELAY_USEC),
+};
+
+static const struct reg_sequence a500_ec_white_led_enable_seq[] = {
+	REG_SEQ(REG_POWER_LED_ON, 0x0, A500_EC_LED_DELAY_USEC),
+};
+
+static const struct reg_sequence a500_ec_orange_led_enable_seq[] = {
+	REG_SEQ(REG_CHARGE_LED_ON, 0x0, A500_EC_LED_DELAY_USEC),
+};
+
+static int a500_ec_led_brightness_set(struct led_classdev *led_cdev,
+				      enum led_brightness value)
+{
+	struct a500_led *led = container_of(led_cdev, struct a500_led, cdev);
+	struct reg_sequence control_seq[2];
+	unsigned int num_regs = 1;
+
+	if (value) {
+		control_seq[0] = led->enable_seq[0];
+	} else {
+		/*
+		 * There is no separate controls which can disable LEDs
+		 * individually, there is only RESET_LEDS command that turns
+		 * off both LEDs.
+		 *
+		 * RESET_LEDS turns off both LEDs, thus restore other LED if
+		 * it's turned ON.
+		 */
+		if (led->other->cdev.brightness)
+			num_regs = 2;
+
+		control_seq[0] = a500_ec_leds_reset_seq[0];
+		control_seq[1] = led->other->enable_seq[0];
+	}
+
+	return regmap_multi_reg_write(led->rmap, control_seq, num_regs);
+}
+
+static int a500_ec_leds_probe(struct platform_device *pdev)
+{
+	struct a500_led *white_led, *orange_led;
+	struct regmap *rmap;
+	int err;
+
+	rmap = dev_get_regmap(pdev->dev.parent, "KB930");
+	if (!rmap)
+		return -EINVAL;
+
+	/* reset and turn off LEDs */
+	regmap_multi_reg_write(rmap, a500_ec_leds_reset_seq, 2);
+
+	white_led = devm_kzalloc(&pdev->dev, sizeof(*white_led), GFP_KERNEL);
+	if (!white_led)
+		return -ENOMEM;
+
+	white_led->cdev.name = "power:white";
+	white_led->cdev.brightness_set_blocking = a500_ec_led_brightness_set;
+	white_led->cdev.flags = LED_CORE_SUSPENDRESUME;
+	white_led->cdev.max_brightness = 1;
+	white_led->enable_seq = a500_ec_white_led_enable_seq;
+	white_led->rmap = rmap;
+
+	orange_led = devm_kzalloc(&pdev->dev, sizeof(*orange_led), GFP_KERNEL);
+	if (!orange_led)
+		return -ENOMEM;
+
+	orange_led->cdev.name = "power:orange";
+	orange_led->cdev.brightness_set_blocking = a500_ec_led_brightness_set;
+	orange_led->cdev.flags = LED_CORE_SUSPENDRESUME;
+	orange_led->cdev.max_brightness = 1;
+	orange_led->enable_seq = a500_ec_orange_led_enable_seq;
+	orange_led->rmap = rmap;
+
+	white_led->other = orange_led;
+	orange_led->other = white_led;
+
+	err = devm_led_classdev_register(&pdev->dev, &white_led->cdev);
+	if (err) {
+		dev_err(&pdev->dev, "failed to register white LED\n");
+		return err;
+	}
+
+	err = devm_led_classdev_register(&pdev->dev, &orange_led->cdev);
+	if (err) {
+		dev_err(&pdev->dev, "failed to register orange LED\n");
+		return err;
+	}
+
+	return 0;
+}
+
+static struct platform_driver a500_ec_leds_driver = {
+	.driver = {
+		.name = "acer-a500-iconia-leds",
+	},
+	.probe = a500_ec_leds_probe,
+};
+module_platform_driver(a500_ec_leds_driver);
+
+MODULE_DESCRIPTION("LED driver for Acer Iconia Tab A500 Power Button");
+MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
+MODULE_ALIAS("platform:acer-a500-iconia-leds");
+MODULE_LICENSE("GPL");
-- 
2.27.0

Re: [PATCH v3 4/5] leds: Add driver for Acer Iconia Tab A500

[Pavel Machek]

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On Sun 2020-09-06 22:51:02, Dmitry Osipenko wrote:
> Acer Iconia Tab A500 is an Android tablet device which has two LEDs
> embedded into the Power Button. Orange LED indicates "battery charging"
> status and white LED indicates "wake-up/charge-done" status. The new LED
> driver provides control over both LEDs to userspace.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>

Thanks, applied.

									Pavel
									
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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Re: [PATCH v3 4/5] leds: Add driver for Acer Iconia Tab A500

[Dmitry Osipenko]

24.09.2020 15:00, Pavel Machek пишет:
> On Sun 2020-09-06 22:51:02, Dmitry Osipenko wrote:
>> Acer Iconia Tab A500 is an Android tablet device which has two LEDs
>> embedded into the Power Button. Orange LED indicates "battery charging"
>> status and white LED indicates "wake-up/charge-done" status. The new LED
>> driver provides control over both LEDs to userspace.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> 
> Thanks, applied.

Thank you :)

[PATCH v3 5/5] ARM: tegra: acer-a500: Add Embedded Controller

[Dmitry Osipenko]

This patch adds device-tree node for the Embedded Controller which is
found on the Picasso board. The Embedded Controller itself is ENE KB930,
it provides functions like battery-gauge/LED/GPIO/etc and it uses firmware
that is specifically customized for the Acer A500 device.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 arch/arm/boot/dts/tegra20-acer-a500-picasso.dts | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/arch/arm/boot/dts/tegra20-acer-a500-picasso.dts b/arch/arm/boot/dts/tegra20-acer-a500-picasso.dts
index 2d683c9a1a5d..f92712e4bd34 100644
--- a/arch/arm/boot/dts/tegra20-acer-a500-picasso.dts
+++ b/arch/arm/boot/dts/tegra20-acer-a500-picasso.dts
@@ -502,6 +502,16 @@ panel_ddc: i2c@1 {
 			reg = <1>;
 			#address-cells = <1>;
 			#size-cells = <0>;
+
+			embedded-controller@58 {
+				compatible = "acer,a500-iconia-ec", "ene,kb930";
+				reg = <0x58>;
+
+				system-power-controller;
+
+				monitored-battery = <&bat1010>;
+				power-supplies = <&mains>;
+			};
 		};
 	};
 
@@ -780,6 +790,13 @@ backlight: backlight {
 		default-brightness-level = <20>;
 	};
 
+	bat1010: battery-2s1p {
+		compatible = "simple-battery";
+		charge-full-design-microamp-hours = <3260000>;
+		energy-full-design-microwatt-hours = <24000000>;
+		operating-range-celsius = <0 40>;
+	};
+
 	/* PMIC has a built-in 32KHz oscillator which is used by PMC */
 	clk32k_in: clock@0 {
 		compatible = "fixed-clock";
-- 
2.27.0