[PATCH v3 0/5] ChromeOS Embedded Controller charge control driver

[PATCH v3 0/5] ChromeOS Embedded Controller charge control driver

[Thomas Weißschuh]

Note:
To be useful, this series depends on
commit 08dbad2c7c32 ("mfd: cros_ec: Register charge control subdevice")
from the MFD tree [0].

Add a power supply driver that supports charge thresholds and behaviour
configuration.

This is a complete rework of
"platform/chrome: cros_ec_framework_laptop: new driver" [1], which used
Framework specific EC commands.

The driver propsed in this series only uses upstream CrOS functionality.

Tested on a Framework 13 AMD, Firmware 3.05.

This driver should go through the chrome-platform tree.
Otherwise "platform/chrome: cros_ec_proto: Introduce cros_ec_cmd_versions()"
will conflict with
commit a14a569a9918 ("platform/chrome: cros_ec_proto: Introduce cros_ec_cmd_readmem()")
from chrome-platform/for-next.

The patch
"platform/chrome: cros_ec_proto: Introduce cros_ec_cmd_versions()"
is also part of my series
"hwmon: (cros_ec): fan target, fan pwm control and temperature thresholds"[2].

Based on chrome-platform/for-next.

[0] https://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd.git/commit/?h=for-mfd-next&id=08dbad2c7c3275e0e79190dca139bc65ce775a92
[1] https://lore.kernel.org/lkml/20240505-cros_ec-framework-v1-0-402662d6276b@weissschuh.net/
[2] https://lore.kernel.org/lkml/20240608-cros_ec-hwmon-pwm-v1-0-d29dfc26fbc3@weissschuh.net/

Changes in v3:
- Drop MFD patch that was already applied
  (therefore drop Lee from series recipients)
- Introduce and use devm_battery_hook_register()
- Note that the driver should go through the chrome-platform tree
- Introduce and use cros_ec_cmd_versions()
- Drop logging about impossible charge behaviours
- Use sysfs_attr_init()
- Disable probing on incompatible Framework devices by default
- Link to v2: https://lore.kernel.org/r/20240528-cros_ec-charge-control-v2-0-81fb27e1cff4@weissschuh.net

Changes in v2:
- Accept "0" as charge_start_threshold
- Don't include linux/kernel.h
- Only bind to the first found battery
- Import EC_CMD_CHARGE_CONTROL v3 headers
- Add support for v1 and v3 commands
- Sort mfd cell entry alphabetically
- Link to v1: https://lore.kernel.org/r/20240519-cros_ec-charge-control-v1-0-baf305dc79b8@weissschuh.net

---
Thomas Weißschuh (5):
      ACPI: battery: add devm_battery_hook_register()
      platform/chrome: Update binary interface for EC-based charge control
      platform/chrome: cros_ec_proto: Introduce cros_ec_cmd_versions()
      power: supply: add ChromeOS EC based charge control driver
      power: supply: cros_charge-control: don't probe if Framework control is present

 MAINTAINERS                                    |   6 +
 drivers/acpi/battery.c                         |  15 ++
 drivers/platform/chrome/cros_ec_proto.c        |  26 ++
 drivers/power/supply/Kconfig                   |  12 +
 drivers/power/supply/Makefile                  |   1 +
 drivers/power/supply/cros_charge-control.c     | 359 +++++++++++++++++++++++++
 include/acpi/battery.h                         |   2 +
 include/linux/platform_data/cros_ec_commands.h |  49 +++-
 include/linux/platform_data/cros_ec_proto.h    |   2 +
 9 files changed, 470 insertions(+), 2 deletions(-)
---
base-commit: c8a4bdca928debacf49524d1b09dbf27e88e1f18
change-id: 20240506-cros_ec-charge-control-685617e8ed87

Best regards,
-- 
Thomas Weißschuh <linux@weissschuh.net>

[PATCH v3 1/5] ACPI: battery: add devm_battery_hook_register()

[Thomas Weißschuh]

Add a utility function for device-managed registration of battery hooks.
The function makes it easier to manage the lifecycle of a hook.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 drivers/acpi/battery.c | 15 +++++++++++++++
 include/acpi/battery.h |  2 ++
 2 files changed, 17 insertions(+)

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index b379401ff1c2..6ea979f76f84 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -756,6 +756,21 @@ void battery_hook_register(struct acpi_battery_hook *hook)
 }
 EXPORT_SYMBOL_GPL(battery_hook_register);
 
+static void devm_battery_hook_unregister(void *data)
+{
+	struct acpi_battery_hook *hook = data;
+
+	battery_hook_unregister(hook);
+}
+
+int devm_battery_hook_register(struct device *dev, struct acpi_battery_hook *hook)
+{
+	battery_hook_register(hook);
+
+	return devm_add_action_or_reset(dev, devm_battery_hook_unregister, hook);
+}
+EXPORT_SYMBOL_GPL(devm_battery_hook_register);
+
 /*
  * This function gets called right after the battery sysfs
  * attributes have been added, so that the drivers that
diff --git a/include/acpi/battery.h b/include/acpi/battery.h
index 611a2561a014..c93f16dfb944 100644
--- a/include/acpi/battery.h
+++ b/include/acpi/battery.h
@@ -2,6 +2,7 @@
 #ifndef __ACPI_BATTERY_H
 #define __ACPI_BATTERY_H
 
+#include <linux/device.h>
 #include <linux/power_supply.h>
 
 #define ACPI_BATTERY_CLASS "battery"
@@ -19,5 +20,6 @@ struct acpi_battery_hook {
 
 void battery_hook_register(struct acpi_battery_hook *hook);
 void battery_hook_unregister(struct acpi_battery_hook *hook);
+int devm_battery_hook_register(struct device *dev, struct acpi_battery_hook *hook);
 
 #endif

-- 
2.45.2

Re: [PATCH v3 1/5] ACPI: battery: add devm_battery_hook_register()

[Rafael J. Wysocki]

On Mon, Jun 10, 2024 at 5:52 PM Thomas Weißschuh <linux@weissschuh.net> wrote:
>
> Add a utility function for device-managed registration of battery hooks.
> The function makes it easier to manage the lifecycle of a hook.
>
> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

Please feel free to add

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

to this patch and route it along with the rest of the series as needed.

Thanks!

> ---
>  drivers/acpi/battery.c | 15 +++++++++++++++
>  include/acpi/battery.h |  2 ++
>  2 files changed, 17 insertions(+)
>
> diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
> index b379401ff1c2..6ea979f76f84 100644
> --- a/drivers/acpi/battery.c
> +++ b/drivers/acpi/battery.c
> @@ -756,6 +756,21 @@ void battery_hook_register(struct acpi_battery_hook *hook)
>  }
>  EXPORT_SYMBOL_GPL(battery_hook_register);
>
> +static void devm_battery_hook_unregister(void *data)
> +{
> +       struct acpi_battery_hook *hook = data;
> +
> +       battery_hook_unregister(hook);
> +}
> +
> +int devm_battery_hook_register(struct device *dev, struct acpi_battery_hook *hook)
> +{
> +       battery_hook_register(hook);
> +
> +       return devm_add_action_or_reset(dev, devm_battery_hook_unregister, hook);
> +}
> +EXPORT_SYMBOL_GPL(devm_battery_hook_register);
> +
>  /*
>   * This function gets called right after the battery sysfs
>   * attributes have been added, so that the drivers that
> diff --git a/include/acpi/battery.h b/include/acpi/battery.h
> index 611a2561a014..c93f16dfb944 100644
> --- a/include/acpi/battery.h
> +++ b/include/acpi/battery.h
> @@ -2,6 +2,7 @@
>  #ifndef __ACPI_BATTERY_H
>  #define __ACPI_BATTERY_H
>
> +#include <linux/device.h>
>  #include <linux/power_supply.h>
>
>  #define ACPI_BATTERY_CLASS "battery"
> @@ -19,5 +20,6 @@ struct acpi_battery_hook {
>
>  void battery_hook_register(struct acpi_battery_hook *hook);
>  void battery_hook_unregister(struct acpi_battery_hook *hook);
> +int devm_battery_hook_register(struct device *dev, struct acpi_battery_hook *hook);
>
>  #endif
>
> --
> 2.45.2
>
>

[PATCH v3 2/5] platform/chrome: Update binary interface for EC-based charge control

[Thomas Weißschuh]

The charge-control command v2/v3 is more featureful than v1, it
additionally supports charge thresholds.

The definitions were imported from ChromeOS EC commit
32870d602317 ("squirtle: modify motionsense rotation matrix")

Acked-by: Tzung-Bi Shih <tzungbi@kernel.org>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 include/linux/platform_data/cros_ec_commands.h | 49 ++++++++++++++++++++++++--
 1 file changed, 47 insertions(+), 2 deletions(-)

diff --git a/include/linux/platform_data/cros_ec_commands.h b/include/linux/platform_data/cros_ec_commands.h
index ec598057d1da..e574b790be6f 100644
--- a/include/linux/platform_data/cros_ec_commands.h
+++ b/include/linux/platform_data/cros_ec_commands.h
@@ -3843,16 +3843,61 @@ struct ec_params_i2c_write {
  * discharge the battery.
  */
 #define EC_CMD_CHARGE_CONTROL 0x0096
-#define EC_VER_CHARGE_CONTROL 1
+#define EC_VER_CHARGE_CONTROL 3
 
 enum ec_charge_control_mode {
 	CHARGE_CONTROL_NORMAL = 0,
 	CHARGE_CONTROL_IDLE,
 	CHARGE_CONTROL_DISCHARGE,
+	/* Add no more entry below. */
+	CHARGE_CONTROL_COUNT,
+};
+
+#define EC_CHARGE_MODE_TEXT                               \
+	{                                                 \
+		[CHARGE_CONTROL_NORMAL] = "NORMAL",       \
+		[CHARGE_CONTROL_IDLE] = "IDLE",           \
+		[CHARGE_CONTROL_DISCHARGE] = "DISCHARGE", \
+	}
+
+enum ec_charge_control_cmd {
+	EC_CHARGE_CONTROL_CMD_SET = 0,
+	EC_CHARGE_CONTROL_CMD_GET,
+};
+
+enum ec_charge_control_flag {
+	EC_CHARGE_CONTROL_FLAG_NO_IDLE = BIT(0),
 };
 
 struct ec_params_charge_control {
-	uint32_t mode;  /* enum charge_control_mode */
+	uint32_t mode; /* enum charge_control_mode */
+
+	/* Below are the fields added in V2. */
+	uint8_t cmd; /* enum ec_charge_control_cmd. */
+	uint8_t flags; /* enum ec_charge_control_flag (v3+) */
+	/*
+	 * Lower and upper thresholds for battery sustainer. This struct isn't
+	 * named to avoid tainting foreign projects' name spaces.
+	 *
+	 * If charge mode is explicitly set (e.g. DISCHARGE), battery sustainer
+	 * will be disabled. To disable battery sustainer, set mode=NORMAL,
+	 * lower=-1, upper=-1.
+	 */
+	struct {
+		int8_t lower; /* Display SoC in percentage. */
+		int8_t upper; /* Display SoC in percentage. */
+	} sustain_soc;
+} __ec_align4;
+
+/* Added in v2 */
+struct ec_response_charge_control {
+	uint32_t mode; /* enum charge_control_mode */
+	struct { /* Battery sustainer thresholds */
+		int8_t lower;
+		int8_t upper;
+	} sustain_soc;
+	uint8_t flags; /* enum ec_charge_control_flag (v3+) */
+	uint8_t reserved;
 } __ec_align4;
 
 /*****************************************************************************/

-- 
2.45.2

[PATCH v3 3/5] platform/chrome: cros_ec_proto: Introduce cros_ec_cmd_versions()

[Thomas Weißschuh]

Retrieving the supported versions of a command is a fairly common
operation. Provide a helper for it.

If the command is not supported at all the EC returns
-EINVAL/EC_RES_INVALID_PARAMS.

This error is translated into an empty version mask as that is easier to
handle for callers and they don't need to know about the error details.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 drivers/platform/chrome/cros_ec_proto.c     | 26 ++++++++++++++++++++++++++
 include/linux/platform_data/cros_ec_proto.h |  2 ++
 2 files changed, 28 insertions(+)

diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index fe68be66ee98..9cfe885a5301 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -1069,3 +1069,29 @@ int cros_ec_cmd_readmem(struct cros_ec_device *ec_dev, u8 offset, u8 size, void
 			   &params, sizeof(params), dest, size);
 }
 EXPORT_SYMBOL_GPL(cros_ec_cmd_readmem);
+
+/**
+ * cros_ec_cmd_versions - Get supported version mask.
+ *
+ * @ec_dev: EC device
+ * @cmd: Command to test
+ *
+ * Return: version mask on success, negative error number on failure.
+ */
+int cros_ec_cmd_versions(struct cros_ec_device *ec_dev, u16 cmd)
+{
+	struct ec_params_get_cmd_versions_v1 req = {};
+	struct ec_response_get_cmd_versions resp;
+	int ret;
+
+	req.cmd = cmd;
+	ret = cros_ec_cmd(ec_dev, 1, EC_CMD_GET_CMD_VERSIONS,
+			  &req, sizeof(req), &resp, sizeof(resp));
+	if (ret == -EINVAL)
+		return 0; /* Command not implemented */
+	else if (ret < 0)
+		return ret;
+	else
+		return resp.version_mask;
+}
+EXPORT_SYMBOL_GPL(cros_ec_cmd_versions);
diff --git a/include/linux/platform_data/cros_ec_proto.h b/include/linux/platform_data/cros_ec_proto.h
index 6e9225bdf903..98ab5986f543 100644
--- a/include/linux/platform_data/cros_ec_proto.h
+++ b/include/linux/platform_data/cros_ec_proto.h
@@ -263,6 +263,8 @@ int cros_ec_cmd(struct cros_ec_device *ec_dev, unsigned int version, int command
 
 int cros_ec_cmd_readmem(struct cros_ec_device *ec_dev, u8 offset, u8 size, void *dest);
 
+int cros_ec_cmd_versions(struct cros_ec_device *ec_dev, u16 cmd);
+
 /**
  * cros_ec_get_time_ns() - Return time in ns.
  *

-- 
2.45.2

Re: [PATCH v3 3/5] platform/chrome: cros_ec_proto: Introduce cros_ec_cmd_versions()

[Tzung-Bi Shih]

On Mon, Jun 10, 2024 at 05:51:08PM +0200, Thomas Weißschuh wrote:
> If the command is not supported at all the EC returns
> -EINVAL/EC_RES_INVALID_PARAMS.
> 
> This error is translated into an empty version mask as that is easier to
> handle for callers and they don't need to know about the error details.

I'm not sure whether the behavior is what we want or not as existing
EC_CMD_GET_CMD_VERSIONS usages don't have it.

Re: [PATCH v3 3/5] platform/chrome: cros_ec_proto: Introduce cros_ec_cmd_versions()

[Thomas Weißschuh]

On 2024-06-11 06:32:38+0000, Tzung-Bi Shih wrote:
> On Mon, Jun 10, 2024 at 05:51:08PM +0200, Thomas Weißschuh wrote:
> > If the command is not supported at all the EC returns
> > -EINVAL/EC_RES_INVALID_PARAMS.
> > 
> > This error is translated into an empty version mask as that is easier to
> > handle for callers and they don't need to know about the error details.
> 
> I'm not sure whether the behavior is what we want or not as existing
> EC_CMD_GET_CMD_VERSIONS usages don't have it.

At least the caller of cros_ec_get_host_command_version_mask() expects
it:

ret = cros_ec_get_host_command_version_mask(..., &ver_mask);
if (ret < 0 || ver_mask == 0)
...

ver_mask == 0 will never happen as in that case -EINVAL would have been
returned.

Others, like cros_ec_cec_get_write_cmd_version(), expect the current
semantic of ver_mask != 0 but log spurious errors in case of -EINVAL.
cros_pchg_cmd_ver_check(), works with both semantics, but currently also
logs a spurious error message.

To me the new semantic looks more obvious and much easier to handle.
For each command version a bit is set. no command versions -> no bits.

Re: [PATCH v3 3/5] platform/chrome: cros_ec_proto: Introduce cros_ec_cmd_versions()

[Tzung-Bi Shih]

On Tue, Jun 11, 2024 at 09:23:24AM +0200, Thomas Weißschuh wrote:
> On 2024-06-11 06:32:38+0000, Tzung-Bi Shih wrote:
> > On Mon, Jun 10, 2024 at 05:51:08PM +0200, Thomas Weißschuh wrote:
> > > If the command is not supported at all the EC returns
> > > -EINVAL/EC_RES_INVALID_PARAMS.
> > > 
> > > This error is translated into an empty version mask as that is easier to
> > > handle for callers and they don't need to know about the error details.
> > 
> > I'm not sure whether the behavior is what we want or not as existing
> > EC_CMD_GET_CMD_VERSIONS usages don't have it.
> 
> At least the caller of cros_ec_get_host_command_version_mask() expects
> it:
> 
> ret = cros_ec_get_host_command_version_mask(..., &ver_mask);
> if (ret < 0 || ver_mask == 0)
> ...
> 
> ver_mask == 0 will never happen as in that case -EINVAL would have been
> returned.
> 
> Others, like cros_ec_cec_get_write_cmd_version(), expect the current
> semantic of ver_mask != 0 but log spurious errors in case of -EINVAL.
> cros_pchg_cmd_ver_check(), works with both semantics, but currently also
> logs a spurious error message.
> 
> To me the new semantic looks more obvious and much easier to handle.
> For each command version a bit is set. no command versions -> no bits.

Ack.

Re: [PATCH v3 3/5] platform/chrome: cros_ec_proto: Introduce cros_ec_cmd_versions()

[Tzung-Bi Shih]

On Mon, Jun 10, 2024 at 05:51:08PM +0200, Thomas Weißschuh wrote:
> +/**
> + * cros_ec_cmd_versions - Get supported version mask.

I guess we would like to call it something like "cros_ec_get_cmd_versions".

> + *
> + * @ec_dev: EC device
> + * @cmd: Command to test
> + *
> + * Return: version mask on success, negative error number on failure.
> + */
> +int cros_ec_cmd_versions(struct cros_ec_device *ec_dev, u16 cmd)

Could it support a "version" parameter as existing EC_CMD_GET_CMD_VERSIONS
usages use both versions?  An `u16 cmd` parameter and down-cast to u8 for v0
should be fine. (ec_params_get_cmd_versions vs. ec_params_get_cmd_versions_v1)

Re: [PATCH v3 3/5] platform/chrome: cros_ec_proto: Introduce cros_ec_cmd_versions()

[Thomas Weißschuh]

On 2024-06-11 11:35:39+0000, Tzung-Bi Shih wrote:
> On Mon, Jun 10, 2024 at 05:51:08PM +0200, Thomas Weißschuh wrote:
> > +/**
> > + * cros_ec_cmd_versions - Get supported version mask.
> 
> I guess we would like to call it something like "cros_ec_get_cmd_versions".

Ack.

> > + *
> > + * @ec_dev: EC device
> > + * @cmd: Command to test
> > + *
> > + * Return: version mask on success, negative error number on failure.
> > + */
> > +int cros_ec_cmd_versions(struct cros_ec_device *ec_dev, u16 cmd)
> 
> Could it support a "version" parameter as existing EC_CMD_GET_CMD_VERSIONS
> usages use both versions?  An `u16 cmd` parameter and down-cast to u8 for v0
> should be fine. (ec_params_get_cmd_versions vs. ec_params_get_cmd_versions_v1)

Ack.

Or we could automatically use v0 if cmd <= U8_MAX?

Re: [PATCH v3 3/5] platform/chrome: cros_ec_proto: Introduce cros_ec_cmd_versions()

[Tzung-Bi Shih]

On Tue, Jun 11, 2024 at 02:14:33PM +0200, Thomas Weißschuh wrote:
> On 2024-06-11 11:35:39+0000, Tzung-Bi Shih wrote:
> > On Mon, Jun 10, 2024 at 05:51:08PM +0200, Thomas Weißschuh wrote:
> > > + *
> > > + * @ec_dev: EC device
> > > + * @cmd: Command to test
> > > + *
> > > + * Return: version mask on success, negative error number on failure.
> > > + */
> > > +int cros_ec_cmd_versions(struct cros_ec_device *ec_dev, u16 cmd)
> > 
> > Could it support a "version" parameter as existing EC_CMD_GET_CMD_VERSIONS
> > usages use both versions?  An `u16 cmd` parameter and down-cast to u8 for v0
> > should be fine. (ec_params_get_cmd_versions vs. ec_params_get_cmd_versions_v1)
> 
> Ack.
> 
> Or we could automatically use v0 if cmd <= U8_MAX?

Ack.  Looks feasible.

[PATCH v3 4/5] power: supply: add ChromeOS EC based charge control driver

[Thomas Weißschuh]

The ChromeOS Embedded Controller implements a command to control charge
thresholds and behaviour.

Use it to implement the standard Linux charge_control_start_threshold,
charge_control_end_threshold and charge_behaviour sysfs UAPIs.

The driver is designed to be probed via the cros_ec mfd device.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 MAINTAINERS                                |   6 +
 drivers/power/supply/Kconfig               |  12 +
 drivers/power/supply/Makefile              |   1 +
 drivers/power/supply/cros_charge-control.c | 337 +++++++++++++++++++++++++++++
 4 files changed, 356 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index e4e6aad46668..8101cd0df305 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5135,6 +5135,11 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/sound/google,cros-ec-codec.yaml
 F:	sound/soc/codecs/cros_ec_codec.*
 
+CHROMEOS EC CHARGE CONTROL
+M:	Thomas Weißschuh <thomas@weissschuh.net>
+S:	Maintained
+F:	drivers/power/supply/cros_charge-control.c
+
 CHROMEOS EC HARDWARE MONITORING
 M:	Thomas Weißschuh <thomas@weissschuh.net>
 L:	chrome-platform@lists.linux.dev
@@ -5148,6 +5153,7 @@ M:	Benson Leung <bleung@chromium.org>
 R:	Guenter Roeck <groeck@chromium.org>
 L:	chrome-platform@lists.linux.dev
 S:	Maintained
+F:	drivers/power/supply/cros_charge-control.c
 F:	drivers/power/supply/cros_usbpd-charger.c
 N:	cros_ec
 N:	cros-ec
diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 3e31375491d5..f6321a42aa53 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -860,6 +860,18 @@ config CHARGER_CROS_PCHG
 	  the peripheral charge ports from the EC and converts that into
 	  power_supply properties.
 
+config CHARGER_CROS_CONTROL
+	tristate "ChromeOS EC based charge control"
+	depends on MFD_CROS_EC_DEV
+	depends on ACPI_BATTERY
+	default MFD_CROS_EC_DEV
+	help
+	  Say Y here to enable ChromeOS EC based battery charge control.
+	  This driver can manage charge thresholds and behaviour.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called cros_charge-control.
+
 config CHARGER_SC2731
 	tristate "Spreadtrum SC2731 charger driver"
 	depends on MFD_SC27XX_PMIC || COMPILE_TEST
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index 58b567278034..31ca6653a564 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -100,6 +100,7 @@ obj-$(CONFIG_CHARGER_TPS65090)	+= tps65090-charger.o
 obj-$(CONFIG_CHARGER_TPS65217)	+= tps65217_charger.o
 obj-$(CONFIG_AXP288_FUEL_GAUGE) += axp288_fuel_gauge.o
 obj-$(CONFIG_AXP288_CHARGER)	+= axp288_charger.o
+obj-$(CONFIG_CHARGER_CROS_CONTROL)	+= cros_charge-control.o
 obj-$(CONFIG_CHARGER_CROS_USBPD)	+= cros_usbpd-charger.o
 obj-$(CONFIG_CHARGER_CROS_PCHG)	+= cros_peripheral_charger.o
 obj-$(CONFIG_CHARGER_SC2731)	+= sc2731_charger.o
diff --git a/drivers/power/supply/cros_charge-control.c b/drivers/power/supply/cros_charge-control.c
new file mode 100644
index 000000000000..056346850c6d
--- /dev/null
+++ b/drivers/power/supply/cros_charge-control.c
@@ -0,0 +1,337 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  ChromeOS EC driver for charge control
+ *
+ *  Copyright (C) 2024 Thomas Weißschuh <linux@weissschuh.net>
+ */
+#include <acpi/battery.h>
+#include <linux/container_of.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_data/cros_ec_commands.h>
+#include <linux/platform_data/cros_ec_proto.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+
+#define DRV_NAME	"cros-charge-control"
+
+#define EC_CHARGE_CONTROL_BEHAVIOURS	(BIT(POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO)             | \
+					 BIT(POWER_SUPPLY_CHARGE_BEHAVIOUR_INHIBIT_CHARGE)   | \
+					 BIT(POWER_SUPPLY_CHARGE_BEHAVIOUR_FORCE_DISCHARGE))
+
+enum CROS_CHCTL_ATTR {
+	CROS_CHCTL_ATTR_START_THRESHOLD,
+	CROS_CHCTL_ATTR_END_THRESHOLD,
+	CROS_CHCTL_ATTR_CHARGE_BEHAVIOUR,
+
+	_CROS_CHCTL_ATTR_COUNT,
+};
+
+/*
+ * Semantics of data *returned* from the EC API and Linux sysfs differ
+ * slightly, also the v1 API can not return any data.
+ * To match the expected sysfs API, data is never read back from the EC but
+ * cached in the driver.
+ *
+ * Changes to the EC bypassing the driver will not be reflected in sysfs.
+ * Any change to "charge_behaviour" will synchronize the EC with the driver state.
+ */
+
+struct cros_chctl_priv {
+	struct cros_ec_device *cros_ec;
+	struct acpi_battery_hook battery_hook;
+	struct power_supply *hooked_battery;
+	u8 cmd_version;
+
+	/* The callbacks need to access this priv structure.
+	 * As neither the struct device nor power_supply are under the drivers
+	 * control, embed the attributes within priv to use with container_of().
+	 */
+	struct device_attribute device_attrs[_CROS_CHCTL_ATTR_COUNT];
+	struct attribute *attributes[_CROS_CHCTL_ATTR_COUNT];
+	struct attribute_group group;
+
+	enum power_supply_charge_behaviour current_behaviour;
+	u8 current_start_threshold, current_end_threshold;
+};
+
+static int cros_chctl_send_charge_control_cmd(struct cros_ec_device *cros_ec,
+					      u8 cmd_version, struct ec_params_charge_control *req)
+{
+	static const u8 outsizes[] = {
+		[1] = offsetof(struct ec_params_charge_control, cmd),
+		[2] = sizeof(struct ec_params_charge_control),
+		[3] = sizeof(struct ec_params_charge_control),
+	};
+
+	struct {
+		struct cros_ec_command msg;
+		union {
+			struct ec_params_charge_control req;
+			struct ec_response_charge_control resp;
+		} __packed data;
+	} __packed buf = {
+		.msg = {
+			.command = EC_CMD_CHARGE_CONTROL,
+			.version = cmd_version,
+			.insize  = 0,
+			.outsize = outsizes[cmd_version],
+		},
+		.data.req = *req,
+	};
+
+	return cros_ec_cmd_xfer_status(cros_ec, &buf.msg);
+}
+
+static int cros_chctl_configure_ec(struct cros_chctl_priv *priv)
+{
+	struct ec_params_charge_control req = { };
+
+	req.cmd = EC_CHARGE_CONTROL_CMD_SET;
+
+	switch (priv->current_behaviour) {
+	case POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO:
+		req.mode = CHARGE_CONTROL_NORMAL;
+		break;
+	case POWER_SUPPLY_CHARGE_BEHAVIOUR_INHIBIT_CHARGE:
+		req.mode = CHARGE_CONTROL_IDLE;
+		break;
+	case POWER_SUPPLY_CHARGE_BEHAVIOUR_FORCE_DISCHARGE:
+		req.mode = CHARGE_CONTROL_DISCHARGE;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (priv->current_behaviour == POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO &&
+	    !(priv->current_start_threshold == 0 && priv->current_end_threshold == 100)) {
+		req.sustain_soc.lower = priv->current_start_threshold;
+		req.sustain_soc.upper = priv->current_end_threshold;
+	} else {
+		/* Disable charging limits */
+		req.sustain_soc.lower = -1;
+		req.sustain_soc.upper = -1;
+	}
+
+	return cros_chctl_send_charge_control_cmd(priv->cros_ec, priv->cmd_version, &req);
+}
+
+static struct cros_chctl_priv *cros_chctl_attr_to_priv(struct attribute *attr,
+						       enum CROS_CHCTL_ATTR idx)
+{
+	struct device_attribute *dev_attr = container_of(attr, struct device_attribute, attr);
+
+	return container_of(dev_attr, struct cros_chctl_priv, device_attrs[idx]);
+}
+
+static ssize_t cros_chctl_store_threshold(struct device *dev, struct cros_chctl_priv *priv,
+					  int is_end_threshold, const char *buf, size_t count)
+{
+	int ret, val;
+
+	ret = kstrtoint(buf, 10, &val);
+	if (ret < 0)
+		return ret;
+	if (val < 0 || val > 100)
+		return -EINVAL;
+
+	if (is_end_threshold) {
+		if (val <= priv->current_start_threshold)
+			return -EINVAL;
+		priv->current_end_threshold = val;
+	} else {
+		if (val >= priv->current_end_threshold)
+			return -EINVAL;
+		priv->current_start_threshold = val;
+	}
+
+	if (priv->current_behaviour == POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO) {
+		ret = cros_chctl_configure_ec(priv);
+		if (ret < 0)
+			return ret;
+	}
+
+	return count;
+}
+
+static ssize_t charge_control_start_threshold_show(struct device *dev,
+						   struct device_attribute *attr,
+						   char *buf)
+{
+	struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(&attr->attr,
+							       CROS_CHCTL_ATTR_START_THRESHOLD);
+
+	return sysfs_emit(buf, "%u\n", (unsigned int)priv->current_start_threshold);
+}
+
+static ssize_t charge_control_start_threshold_store(struct device *dev,
+						    struct device_attribute *attr,
+						    const char *buf, size_t count)
+{
+	struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(&attr->attr,
+							       CROS_CHCTL_ATTR_START_THRESHOLD);
+
+	return cros_chctl_store_threshold(dev, priv, 0, buf, count);
+}
+
+static ssize_t charge_control_end_threshold_show(struct device *dev, struct device_attribute *attr,
+						 char *buf)
+{
+	struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(&attr->attr,
+							       CROS_CHCTL_ATTR_END_THRESHOLD);
+
+	return sysfs_emit(buf, "%u\n", (unsigned int)priv->current_end_threshold);
+}
+
+static ssize_t charge_control_end_threshold_store(struct device *dev, struct device_attribute *attr,
+						  const char *buf, size_t count)
+{
+	struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(&attr->attr,
+							       CROS_CHCTL_ATTR_END_THRESHOLD);
+
+	return cros_chctl_store_threshold(dev, priv, 1, buf, count);
+}
+
+static ssize_t charge_behaviour_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(&attr->attr,
+							       CROS_CHCTL_ATTR_CHARGE_BEHAVIOUR);
+
+	return power_supply_charge_behaviour_show(dev, EC_CHARGE_CONTROL_BEHAVIOURS,
+						  priv->current_behaviour, buf);
+}
+
+static ssize_t charge_behaviour_store(struct device *dev, struct device_attribute *attr,
+				      const char *buf, size_t count)
+{
+	struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(&attr->attr,
+							       CROS_CHCTL_ATTR_CHARGE_BEHAVIOUR);
+	enum power_supply_charge_behaviour behaviour;
+	int ret;
+
+	behaviour = power_supply_charge_behaviour_parse(EC_CHARGE_CONTROL_BEHAVIOURS, buf);
+	if (behaviour < 0)
+		return behaviour;
+
+	priv->current_behaviour = behaviour;
+
+	ret = cros_chctl_configure_ec(priv);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static umode_t cros_chtl_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n)
+{
+	struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(attr, n);
+
+	if (priv->cmd_version < 2) {
+		if (n == CROS_CHCTL_ATTR_START_THRESHOLD)
+			return 0;
+		if (n == CROS_CHCTL_ATTR_END_THRESHOLD)
+			return 0;
+	}
+
+	return attr->mode;
+}
+
+static int cros_chctl_add_battery(struct power_supply *battery, struct acpi_battery_hook *hook)
+{
+	struct cros_chctl_priv *priv = container_of(hook, struct cros_chctl_priv, battery_hook);
+
+	if (priv->hooked_battery)
+		return 0;
+
+	priv->hooked_battery = battery;
+	return device_add_group(&battery->dev, &priv->group);
+}
+
+static int cros_chctl_remove_battery(struct power_supply *battery, struct acpi_battery_hook *hook)
+{
+	struct cros_chctl_priv *priv = container_of(hook, struct cros_chctl_priv, battery_hook);
+
+	if (priv->hooked_battery == battery) {
+		device_remove_group(&battery->dev, &priv->group);
+		priv->hooked_battery = NULL;
+	}
+
+	return 0;
+}
+
+static int cros_chctl_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
+	struct cros_ec_device *cros_ec = ec_dev->ec_dev;
+	struct cros_chctl_priv *priv;
+	size_t i;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	ret = cros_ec_cmd_versions(cros_ec, EC_CMD_CHARGE_CONTROL);
+	if (ret < 0)
+		return ret;
+	else if (ret & EC_VER_MASK(3))
+		priv->cmd_version = 3;
+	else if (ret & EC_VER_MASK(2))
+		priv->cmd_version = 2;
+	else if (ret & EC_VER_MASK(1))
+		priv->cmd_version = 1;
+	else
+		return -ENODEV;
+
+	dev_dbg(dev, "Command version: %u\n", (unsigned int)priv->cmd_version);
+
+	priv->cros_ec = cros_ec;
+	priv->device_attrs[CROS_CHCTL_ATTR_START_THRESHOLD] =
+		(struct device_attribute)__ATTR_RW(charge_control_start_threshold);
+	priv->device_attrs[CROS_CHCTL_ATTR_END_THRESHOLD] =
+		(struct device_attribute)__ATTR_RW(charge_control_end_threshold);
+	priv->device_attrs[CROS_CHCTL_ATTR_CHARGE_BEHAVIOUR] =
+		(struct device_attribute)__ATTR_RW(charge_behaviour);
+	for (i = 0; i < _CROS_CHCTL_ATTR_COUNT; i++) {
+		sysfs_attr_init(&priv->device_attrs[i].attr);
+		priv->attributes[i] = &priv->device_attrs[i].attr;
+	}
+	priv->attributes[_CROS_CHCTL_ATTR_COUNT] = NULL;
+	priv->group.is_visible = cros_chtl_attr_is_visible;
+	priv->group.attrs = priv->attributes;
+
+	priv->battery_hook.name = dev_name(dev),
+	priv->battery_hook.add_battery = cros_chctl_add_battery,
+	priv->battery_hook.remove_battery = cros_chctl_remove_battery,
+
+	priv->current_behaviour = POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO;
+	priv->current_start_threshold = 0;
+	priv->current_end_threshold = 100;
+
+	/* Bring EC into well-known state */
+	ret = cros_chctl_configure_ec(priv);
+	if (ret == -EOPNOTSUPP)
+		return -ENODEV;
+	else if (ret < 0)
+		return ret;
+
+	return devm_battery_hook_register(dev, &priv->battery_hook);
+}
+
+static const struct platform_device_id cros_chctl_id[] = {
+	{ DRV_NAME, 0 },
+	{ }
+};
+
+static struct platform_driver cros_chctl_driver = {
+	.driver.name	= DRV_NAME,
+	.probe		= cros_chctl_probe,
+	.id_table	= cros_chctl_id,
+};
+module_platform_driver(cros_chctl_driver);
+
+MODULE_DEVICE_TABLE(platform, cros_chctl_id);
+MODULE_DESCRIPTION("ChromeOS EC charge control");
+MODULE_AUTHOR("Thomas Weißschuh <linux@weissschuh.net>");
+MODULE_LICENSE("GPL");

-- 
2.45.2

[PATCH v3 5/5] power: supply: cros_charge-control: don't probe if Framework control is present

[Thomas Weißschuh]

Framework laptops implement a custom charge control EC command.
The upstream CrOS EC command is also present and functional but can get
overridden by the custom one.

Until Framework make both commands compatible or remove their custom
one, don't load the driver on those machines.

If the user knows they are not going to use the custom command they can
use a module parameter to load cros_charge-control anyways.

Note that the UEFI setup configuration for battery control also uses
their custom command.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 drivers/power/supply/cros_charge-control.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/power/supply/cros_charge-control.c b/drivers/power/supply/cros_charge-control.c
index 056346850c6d..3688e021b4da 100644
--- a/drivers/power/supply/cros_charge-control.c
+++ b/drivers/power/supply/cros_charge-control.c
@@ -6,6 +6,7 @@
  */
 #include <acpi/battery.h>
 #include <linux/container_of.h>
+#include <linux/dmi.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/platform_data/cros_ec_commands.h>
@@ -259,6 +260,19 @@ static int cros_chctl_remove_battery(struct power_supply *battery, struct acpi_b
 	return 0;
 }
 
+static bool probe_with_fwk_charge_control;
+module_param(probe_with_fwk_charge_control, bool, 0644);
+MODULE_PARM_DESC(probe_with_fwk_charge_control,
+		 "Probe the driver in the presence of the custom Framework EC charge control");
+
+static int cros_chctl_fwk_charge_control_versions(struct cros_ec_device *cros_ec)
+{
+	if (!dmi_match(DMI_SYS_VENDOR, "Framework"))
+		return 0;
+
+	return cros_ec_cmd_versions(cros_ec, 0x3E03 /* FW_EC_CMD_CHARGE_LIMIT */);
+}
+
 static int cros_chctl_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -268,6 +282,14 @@ static int cros_chctl_probe(struct platform_device *pdev)
 	size_t i;
 	int ret;
 
+	ret = cros_chctl_fwk_charge_control_versions(cros_ec);
+	if (ret < 0)
+		return ret;
+	if (ret > 0 && !probe_with_fwk_charge_control) {
+		dev_info(dev, "Framework charge control detected, not probing\n");
+		return -ENODEV;
+	}
+
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;

-- 
2.45.2