platform: chrome: Add cros-usbpd-notify driver

Add the cros-usbpd-notify driver as a subdevice on platforms that support the EC_FEATURE_USB_PD EC feature flag and don't have the ACPI PD notification device defined.

This driver allows other cros-ec devices to receive PD event notifications from the Chrome OS Embedded Controller (EC) via a notification chain.

Signed-off-by Prashant Malani <[email protected]>

---

Changes in v6:
- No changes.

Changes in v5:
- Updated the IS_ENABLED() check to check for CONFIG_OF instead of !CONFIG_ACPI according to upstream comments.

Changes in v4:
- Removed #ifndef usage; instead, moved cros-usbpd-notify to a separate mfd_cell and used an IS_ENABLED() check.
- Changed commit title and description slightly to reflect change in code.

 drivers/mfd/cros_ec_dev.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

Add the cros-usbpd-notify driver as a subdevice on platforms that support the EC_FEATURE_USB_PD EC feature flag and don't have the ACPI PD notification device defined.

This driver allows other cros-ec devices to receive PD event notifications from the Chrome OS Embedded Controller (EC) via a notification chain.

Signed-off-by Prashant Malani <[email protected]>

---

Changes in v6:
- No changes.

Changes in v5:
- Updated the IS_ENABLED() check to check for CONFIG_OF instead of !CONFIG_ACPI according to upstream comments.

Changes in v4:
- Removed #ifndef usage; instead, moved cros-usbpd-notify to a separate mfd_cell and used an IS_ENABLED() check.
- Changed commit title and description slightly to reflect change in code.

 drivers/mfd/cros_ec_dev.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

drivers/mfd/cros_ec_dev.c +22 -0

index c4b977a5dd966..d0c28a4c10ad0 100644
@@ -5,6 +5,7 @@
  * Copyright (C) 2014 Google, Inc.
  */
 
+#include <linux/kconfig.h>
 #include <linux/mfd/core.h>
 #include <linux/mfd/cros_ec.h>
 #include <linux/module.h>

@@ -87,6 +88,10 @@ static const struct mfd_cell cros_usbpd_charger_cells[] = {
 	{ .name = "cros-usbpd-logger", },
 };
 
+static const struct mfd_cell cros_usbpd_notify_cells[] = {
+	{ .name = "cros-usbpd-notify", },
+};
+
 static const struct cros_feature_to_cells cros_subdevices[] = {
 	{
 		.id		= EC_FEATURE_CEC,

@@ -202,6 +207,23 @@ static int ec_device_probe(struct platform_device *pdev)
 		}
 	}
 
+	/*
+	 * The PD notifier driver cell is separate since it only needs to be
+	 * explicitly added on platforms that don't have the PD notifier ACPI
+	 * device entry defined.
+	 */
+	if (IS_ENABLED(CONFIG_OF)) {
+		if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) {
+			retval = mfd_add_hotplug_devices(ec->dev,
+					cros_usbpd_notify_cells,
+					ARRAY_SIZE(cros_usbpd_notify_cells));
+			if (retval)
+				dev_err(ec->dev,
+					"failed to add PD notify devices: %d\n",
+					retval);
+		}
+	}
+
 	/*
 	 * The following subdevices cannot be detected by sending the
 	 * EC_FEATURE_GET_CMD to the Embedded Controller device.

Signature · 1 line

2.25.0.341.g760bfbb309-goog

Add the cros-usbpd-notify driver as a subdevice on platforms that support the EC_FEATURE_USB_PD EC feature flag and don't have the ACPI PD notification device defined.

This driver allows other cros-ec devices to receive PD event notifications from the Chrome OS Embedded Controller (EC) via a notification chain.

Signed-off-by Prashant Malani <[email protected]>

---

Changes in v6:
- No changes.

Changes in v5:
- Updated the IS_ENABLED() check to check for CONFIG_OF instead of !CONFIG_ACPI according to upstream comments.

Changes in v4:
- Removed #ifndef usage; instead, moved cros-usbpd-notify to a separate mfd_cell and used an IS_ENABLED() check.
- Changed commit title and description slightly to reflect change in code.

 drivers/mfd/cros_ec_dev.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

From: Jon Flatley <[email protected]>

There's a bug on ACPI platforms where host events from the ECPD ACPI device never make their way to the cros-ec-usbpd-charger driver. This makes it so the only time the charger driver updates its state is when user space accesses its sysfs attributes.

Now that these events have been unified into a single notifier chain on both ACPI and non-ACPI platforms, update the charger driver to use this new notifier.

Signed-off-by Jon Flatley <[email protected]>

Signed-off-by Prashant Malani <[email protected]>

---

Changes in v6([email protected]):
- Patch first introduced into the series in v6.

 drivers/power/supply/Kconfig              |  2 +-
 drivers/power/supply/cros_usbpd-charger.c | 50 ++++++++---------------
 2 files changed, 19 insertions(+), 33 deletions(-)

drivers/power/supply/Kconfig +1 -1

index 27164a1d3c7c4..ba74ddd793c3d 100644
@@ -659,7 +659,7 @@ config CHARGER_RT9455
 
 config CHARGER_CROS_USBPD
 	tristate "ChromeOS EC based USBPD charger"
-	depends on CROS_EC
+	depends on CROS_USBPD_NOTIFY
 	default n
 	help
 	  Say Y here to enable ChromeOS EC based USBPD charger

drivers/power/supply/cros_usbpd-charger.c +0 -0

index 6cc7c3910e098..7f7e051262170 100644

drivers/power/supply/cros_usbpd-charger.c +17 -32

 #include <linux/platform_data/cros_ec_proto.h>
 #include <linux/platform_device.h>
 #include <linux/power_supply.h>

@@ -524,32 +525,21 @@ static int cros_usbpd_charger_property_is_writeable(struct power_supply *psy,
 }
 
 static int cros_usbpd_charger_ec_event(struct notifier_block *nb,
-				       unsigned long queued_during_suspend,
+				       unsigned long host_event,
 				       void *_notify)
 {
-	struct cros_ec_device *ec_device;
-	struct charger_data *charger;
-	u32 host_event;
+	struct charger_data *charger = container_of(nb, struct charger_data,
+						    notifier);
 
-	charger = container_of(nb, struct charger_data, notifier);
-	ec_device = charger->ec_device;
-
-	host_event = cros_ec_get_host_event(ec_device);
-	if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU)) {
-		cros_usbpd_charger_power_changed(charger->ports[0]->psy);
-		return NOTIFY_OK;
-	} else {
-		return NOTIFY_DONE;
-	}
+	cros_usbpd_charger_power_changed(charger->ports[0]->psy);
+	return NOTIFY_OK;
 }
 
 static void cros_usbpd_charger_unregister_notifier(void *data)
 {
 	struct charger_data *charger = data;
-	struct cros_ec_device *ec_device = charger->ec_device;
 
-	blocking_notifier_chain_unregister(&ec_device->event_notifier,
-					   &charger->notifier);
+	cros_usbpd_unregister_notify(&charger->notifier);
 }
 
 static int cros_usbpd_charger_probe(struct platform_device *pd)

@@ -683,21 +673,17 @@ static int cros_usbpd_charger_probe(struct platform_device *pd)
 		goto fail;
 	}
 
-	if (ec_device->mkbp_event_supported) {
-		/* Get PD events from the EC */
-		charger->notifier.notifier_call = cros_usbpd_charger_ec_event;
-		ret = blocking_notifier_chain_register(
-						&ec_device->event_notifier,
-						&charger->notifier);
-		if (ret < 0) {
-			dev_warn(dev, "failed to register notifier\n");
-		} else {
-			ret = devm_add_action_or_reset(dev,
-					cros_usbpd_charger_unregister_notifier,
-					charger);
-			if (ret < 0)
-				goto fail;
-		}
+	/* Get PD events from the EC */
+	charger->notifier.notifier_call = cros_usbpd_charger_ec_event;
+	ret = cros_usbpd_register_notify(&charger->notifier);
+	if (ret < 0) {
+		dev_warn(dev, "failed to register notifier\n");
+	} else {
+		ret = devm_add_action_or_reset(dev,
+				cros_usbpd_charger_unregister_notifier,
+				charger);
+		if (ret < 0)
+			goto fail;
 	}
 
 	return 0;

Signature · 1 line

2.25.0.341.g760bfbb309-goog

Quoted 7 lines · Prashant Malani

From: Jon Flatley <[email protected]>

There's a bug on ACPI platforms where host events from the ECPD ACPI device never make their way to the cros-ec-usbpd-charger driver. This makes it so the only time the charger driver updates its state is when user space accesses its sysfs attributes.

Quoted 6 lines

Now that these events have been unified into a single notifier chain on both ACPI and non-ACPI platforms, update the charger driver to use this new notifier.

Signed-off-by Jon Flatley <[email protected]>

Signed-off-by Prashant Malani <[email protected]>

Only a minor nit. Otherwise,

Reviewed-by Benson Leung <[email protected]>

Quoted 26 lines

---

Changes in v6([email protected]):
- Patch first introduced into the series in v6.

 drivers/power/supply/Kconfig              |  2 +-
 drivers/power/supply/cros_usbpd-charger.c | 50 ++++++++---------------
 2 files changed, 19 insertions(+), 33 deletions(-)

drivers/power/supply/Kconfig +1 -1

index 27164a1d3c7c4..ba74ddd793c3d 100644
@@ -659,7 +659,7 @@ config CHARGER_RT9455
 
 config CHARGER_CROS_USBPD
      tristate "ChromeOS EC based USBPD charger"
-     depends on CROS_EC
+     depends on CROS_USBPD_NOTIFY
      default n
      help
        Say Y here to enable ChromeOS EC based USBPD charger

drivers/power/supply/cros_usbpd-charger.c +0 -0

index 6cc7c3910e098..7f7e051262170 100644

drivers/power/supply/cros_usbpd-charger.c line 11

Quoted 5 lines

drivers/power/supply/cros_usbpd-charger.c +1 -0

@@ -8,6 +8,7 @@
 #include <linux/mfd/cros_ec.h>
 #include <linux/module.h>
 #include <linux/platform_data/cros_ec_commands.h>
+#include <linux/platform_data/cros_usbpd_notify.h>

Really minor nit. Alphabetize this #include. This insertion should be one line below.

Quoted 77 lines

drivers/power/supply/cros_usbpd-charger.c +17 -33

 #include <linux/platform_data/cros_ec_proto.h>
 #include <linux/platform_device.h>
 #include <linux/power_supply.h>

@@ -524,32 +525,21 @@ static int cros_usbpd_charger_property_is_writeable(struct power_supply *psy,
 }
 
 static int cros_usbpd_charger_ec_event(struct notifier_block *nb,
-                                    unsigned long queued_during_suspend,
+                                    unsigned long host_event,
                                     void *_notify)
 {
-     struct cros_ec_device *ec_device;
-     struct charger_data *charger;
-     u32 host_event;
+     struct charger_data *charger = container_of(nb, struct charger_data,
+                                                 notifier);
 
-     charger = container_of(nb, struct charger_data, notifier);
-     ec_device = charger->ec_device;
-
-     host_event = cros_ec_get_host_event(ec_device);
-     if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU)) {
-             cros_usbpd_charger_power_changed(charger->ports[0]->psy);
-             return NOTIFY_OK;
-     } else {
-             return NOTIFY_DONE;
-     }
+     cros_usbpd_charger_power_changed(charger->ports[0]->psy);
+     return NOTIFY_OK;
 }
 
 static void cros_usbpd_charger_unregister_notifier(void *data)
 {
      struct charger_data *charger = data;
-     struct cros_ec_device *ec_device = charger->ec_device;
 
-     blocking_notifier_chain_unregister(&ec_device->event_notifier,
-                                        &charger->notifier);
+     cros_usbpd_unregister_notify(&charger->notifier);
 }
 
 static int cros_usbpd_charger_probe(struct platform_device *pd)

@@ -683,21 +673,17 @@ static int cros_usbpd_charger_probe(struct platform_device *pd)
              goto fail;
      }
 
-     if (ec_device->mkbp_event_supported) {
-             /* Get PD events from the EC */
-             charger->notifier.notifier_call = cros_usbpd_charger_ec_event;
-             ret = blocking_notifier_chain_register(
-                                             &ec_device->event_notifier,
-                                             &charger->notifier);
-             if (ret < 0) {
-                     dev_warn(dev, "failed to register notifier\n");
-             } else {
-                     ret = devm_add_action_or_reset(dev,
-                                     cros_usbpd_charger_unregister_notifier,
-                                     charger);
-                     if (ret < 0)
-                             goto fail;
-             }
+     /* Get PD events from the EC */
+     charger->notifier.notifier_call = cros_usbpd_charger_ec_event;
+     ret = cros_usbpd_register_notify(&charger->notifier);
+     if (ret < 0) {
+             dev_warn(dev, "failed to register notifier\n");
+     } else {
+             ret = devm_add_action_or_reset(dev,
+                             cros_usbpd_charger_unregister_notifier,
+                             charger);
+             if (ret < 0)
+                     goto fail;
      }
 
      return 0;
--

Quoted 2 lines

2.25.0.341.g760bfbb309-goog

--
Benson Leung
Staff Software Engineer
Chrome OS Kernel
Google Inc.
[email protected]
Chromium OS Project
[email protected]

From: Jon Flatley <[email protected]>

ChromiumOS uses ACPI device with HID "GOOG0003" for power delivery related events. The existing cros-usbpd-charger driver relies on these events without ever actually receiving them on ACPI platforms. This is because in the ChromeOS kernel trees, the GOOG0003 device is owned by an ACPI driver that offers firmware updates to USB-C chargers.

Introduce a new platform driver under cros-ec, the ChromeOS embedded controller, that handles these PD events and dispatches them appropriately over a notifier chain to all drivers that use them.

On platforms that don't have the ACPI device defined, the driver gets instantiated for ECs which support the EC_FEATURE_USB_PD feature bit, and the notification events will get delivered using the MKBP event handling mechanism.

Co-Developed-by Prashant Malani <[email protected]>

Reviewed-by Gwendal Grignou <[email protected]>

Signed-off-by Jon Flatley <[email protected]>

Signed-off-by Prashant Malani <[email protected]>

---

Changes in v6([email protected]):
- Fix build error from typo in cros_usbpd_notify_acpi_device_ids variable name.

Changes in v5([email protected]):
- Split the driver into platform and ACPI variants, each enclosed by CONFIG_OF and CONFIG_ACPI #ifdefs respectively.
- Updated the copyright year to 2020.
- Reworded the commit message and Kconfig description to incorporate the modified driver structure.

Changes in v4([email protected]):
- No code changes, but added new version so that versioning is consistent with the next patch in the series.

Changes in v3 ([email protected]):
- Renamed driver and files from "cros_ec_pd_notify" to "cros_usbpd_notify" to be more consistent with other naming.
- Moved the change to include cros-usbpd-notify in the charger MFD into a separate follow-on patch.

Changes in v2 ([email protected]):
- Removed dependency on DT entry; instead, we will instantiate the driver on detecting EC_FEATURE_USB_PD for non-ACPI platforms.
- Modified the cros-ec-pd-notify device to be an mfd_cell under usbpdcharger for non-ACPI platforms. Altered the platform_probe() call to derive the cros EC structs appropriately.
- Replaced "usbpd_notify" with "pd_notify" in functions and structures.
- Addressed comments from upstream maintainer.

 drivers/platform/chrome/Kconfig               |  10 ++
 drivers/platform/chrome/Makefile              |   1 +
 drivers/platform/chrome/cros_usbpd_notify.c   | 153 ++++++++++++++++++
 .../linux/platform_data/cros_usbpd_notify.h   |  17 ++
 4 files changed, 181 insertions(+)
 create mode 100644 drivers/platform/chrome/cros_usbpd_notify.c
 create mode 100644 include/linux/platform_data/cros_usbpd_notify.h

drivers/platform/chrome/Kconfig +10 -0

index 5f57282a28da0..89df6c991089d 100644
@@ -226,6 +226,16 @@ config CROS_USBPD_LOGGER
 	  To compile this driver as a module, choose M here: the
 	  module will be called cros_usbpd_logger.
 
+config CROS_USBPD_NOTIFY
+	tristate "ChromeOS Type-C power delivery event notifier"
+	depends on CROS_EC
+	help
+	  If you say Y here, you get support for Type-C PD event notifications
+	  from the ChromeOS EC. On ACPI platorms this driver will bind to the
+	  GOOG0003 ACPI device, and on platforms which don't have this device it
+	  will get initialized on ECs which support the feature
+	  EC_FEATURE_USB_PD.
+
 source "drivers/platform/chrome/wilco_ec/Kconfig"
 
 endif # CHROMEOS_PLATFORMS

drivers/platform/chrome/Makefile +1 -0

index aacd5920d8a18..f6465f8ef0b5e 100644
@@ -22,5 +22,6 @@ obj-$(CONFIG_CROS_EC_DEBUGFS)		+= cros_ec_debugfs.o
 obj-$(CONFIG_CROS_EC_SENSORHUB)		+= cros_ec_sensorhub.o
 obj-$(CONFIG_CROS_EC_SYSFS)		+= cros_ec_sysfs.o
 obj-$(CONFIG_CROS_USBPD_LOGGER)		+= cros_usbpd_logger.o
+obj-$(CONFIG_CROS_USBPD_NOTIFY)		+= cros_usbpd_notify.o
 
 obj-$(CONFIG_WILCO_EC)			+= wilco_ec/

drivers/platform/chrome/cros_usbpd_notify.c new file +2 -0

new file mode 100644
index 0000000000000..858e494995843
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*

drivers/platform/chrome/cros_usbpd_notify.c new file +141 -0

+#include <linux/platform_data/cros_ec_proto.h>
+#include <linux/platform_device.h>
+
+#define DRV_NAME "cros-usbpd-notify"
+#define ACPI_DRV_NAME "GOOG0003"
+
+static BLOCKING_NOTIFIER_HEAD(cros_usbpd_notifier_list);
+
+/**
+ * cros_usbpd_register_notify - Register a notifier callback for PD events.
+ * @nb: Notifier block pointer to register
+ *
+ * On ACPI platforms this corresponds to host events on the ECPD
+ * "GOOG0003" ACPI device. On non-ACPI platforms this will filter mkbp events
+ * for USB PD events.
+ *
+ * Return: 0 on success or negative error code.
+ */
+int cros_usbpd_register_notify(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(
+			&cros_usbpd_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(cros_usbpd_register_notify);
+
+
+/**
+ * cros_usbpd_unregister_notify - Unregister notifier callback for PD events.
+ * @nb: Notifier block pointer to unregister
+ *
+ * Unregister a notifier callback that was previously registered with
+ * cros_usbpd_register_notify().
+ */
+void cros_usbpd_unregister_notify(struct notifier_block *nb)
+{
+	blocking_notifier_chain_unregister(&cros_usbpd_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(cros_usbpd_unregister_notify);
+
+#ifdef CONFIG_ACPI
+
+static int cros_usbpd_notify_add_acpi(struct acpi_device *adev)
+{
+	return 0;
+}
+
+static void cros_usbpd_notify_acpi(struct acpi_device *adev, u32 event)
+{
+	blocking_notifier_call_chain(&cros_usbpd_notifier_list, event, NULL);
+}
+
+static const struct acpi_device_id cros_usbpd_notify_acpi_device_ids[] = {
+	{ ACPI_DRV_NAME, 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, cros_usbpd_notify_acpi_device_ids);
+
+static struct acpi_driver cros_usbpd_notify_acpi_driver = {
+	.name = DRV_NAME,
+	.class = DRV_NAME,
+	.ids = cros_usbpd_notify_acpi_device_ids,
+	.ops = {
+		.add = cros_usbpd_notify_add_acpi,
+		.notify = cros_usbpd_notify_acpi,
+	},
+};
+module_acpi_driver(cros_usbpd_notify_acpi_driver);
+
+#endif /* CONFIG_ACPI */
+
+#ifdef CONFIG_OF
+
+static int cros_usbpd_notify_plat(struct notifier_block *nb,
+		unsigned long queued_during_suspend, void *data)
+{
+	struct cros_ec_device *ec_dev = (struct cros_ec_device *)data;
+	u32 host_event = cros_ec_get_host_event(ec_dev);
+
+	if (!host_event)
+		return NOTIFY_BAD;
+
+	if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU)) {
+		blocking_notifier_call_chain(&cros_usbpd_notifier_list,
+				host_event, NULL);
+		return NOTIFY_OK;
+	}
+	return NOTIFY_DONE;
+}
+
+static int cros_usbpd_notify_probe_plat(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent);
+	struct notifier_block *nb;
+	int ret;
+
+	nb = devm_kzalloc(dev, sizeof(*nb), GFP_KERNEL);
+	if (!nb)
+		return -ENOMEM;
+
+	nb->notifier_call = cros_usbpd_notify_plat;
+	dev_set_drvdata(dev, nb);
+
+	ret = blocking_notifier_chain_register(&ecdev->ec_dev->event_notifier,
+						nb);
+	if (ret < 0) {
+		dev_err(dev, "Failed to register notifier\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int cros_usbpd_notify_remove_plat(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent);
+	struct notifier_block *nb =
+		(struct notifier_block *)dev_get_drvdata(dev);
+
+	blocking_notifier_chain_unregister(&ecdev->ec_dev->event_notifier,
+			nb);
+
+	return 0;
+}
+
+static struct platform_driver cros_usbpd_notify_plat_driver = {
+	.driver = {
+		.name = DRV_NAME,
+	},
+	.probe = cros_usbpd_notify_probe_plat,
+	.remove = cros_usbpd_notify_remove_plat,
+};
+module_platform_driver(cros_usbpd_notify_plat_driver);
+
+#endif /* CONFIG_OF */
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ChromeOS power delivery notifier device");
+MODULE_AUTHOR("Jon Flatley <[email protected]>");
+MODULE_ALIAS("platform:" DRV_NAME);

include/linux/platform_data/cros_usbpd_notify.h new file +17 -0

new file mode 100644
index 0000000000000..4f2791722b6d3
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ChromeOS EC Power Delivery Notifier Driver
+ *
+ * Copyright 2020 Google LLC
+ */
+
+#ifndef __LINUX_PLATFORM_DATA_CROS_USBPD_NOTIFY_H
+#define __LINUX_PLATFORM_DATA_CROS_USBPD_NOTIFY_H
+
+#include <linux/notifier.h>
+
+int cros_usbpd_register_notify(struct notifier_block *nb);
+
+void cros_usbpd_unregister_notify(struct notifier_block *nb);
+
+#endif  /* __LINUX_PLATFORM_DATA_CROS_USBPD_NOTIFY_H */

Signature · 1 line

2.25.0.341.g760bfbb309-goog

Quoted 17 lines · Prashant Malani

From: Jon Flatley <[email protected]>

ChromiumOS uses ACPI device with HID "GOOG0003" for power delivery related events. The existing cros-usbpd-charger driver relies on these events without ever actually receiving them on ACPI platforms. This is because in the ChromeOS kernel trees, the GOOG0003 device is owned by an ACPI driver that offers firmware updates to USB-C chargers.

Introduce a new platform driver under cros-ec, the ChromeOS embedded controller, that handles these PD events and dispatches them appropriately over a notifier chain to all drivers that use them.

On platforms that don't have the ACPI device defined, the driver gets instantiated for ECs which support the EC_FEATURE_USB_PD feature bit, and the notification events will get delivered using the MKBP event handling mechanism.

Quoted 4 lines

Co-Developed-by Prashant Malani <[email protected]>

Reviewed-by Gwendal Grignou <[email protected]>

Signed-off-by Jon Flatley <[email protected]>

Signed-off-by Prashant Malani <[email protected]>

Minor nit, otherwise,

Reviewed-by Benson Leung <[email protected]>

Quoted 15 lines

---

drivers/platform/chrome/cros_usbpd_notify.c new file +6 -0

new file mode 100644
index 0000000000000..858e494995843
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2020 Google LLC
+ *
+ * This driver serves as the receiver of cros_ec PD host events.
+ */

drivers/platform/chrome/cros_usbpd_notify.c line 12

Quoted 6 lines

drivers/platform/chrome/cros_usbpd_notify.c new file +6 -0

+
+#include <linux/acpi.h>
+#include <linux/module.h>
+#include <linux/mfd/cros_ec.h>
+#include <linux/platform_data/cros_ec_commands.h>
+#include <linux/platform_data/cros_usbpd_notify.h>

Same nit as other: Alphabetize #include list.

Quoted 166 lines

drivers/platform/chrome/cros_usbpd_notify.c new file +141 -0

+#include <linux/platform_data/cros_ec_proto.h>
+#include <linux/platform_device.h>
+
+#define DRV_NAME "cros-usbpd-notify"
+#define ACPI_DRV_NAME "GOOG0003"
+
+static BLOCKING_NOTIFIER_HEAD(cros_usbpd_notifier_list);
+
+/**
+ * cros_usbpd_register_notify - Register a notifier callback for PD events.
+ * @nb: Notifier block pointer to register
+ *
+ * On ACPI platforms this corresponds to host events on the ECPD
+ * "GOOG0003" ACPI device. On non-ACPI platforms this will filter mkbp events
+ * for USB PD events.
+ *
+ * Return: 0 on success or negative error code.
+ */
+int cros_usbpd_register_notify(struct notifier_block *nb)
+{
+     return blocking_notifier_chain_register(
+                     &cros_usbpd_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(cros_usbpd_register_notify);
+
+
+/**
+ * cros_usbpd_unregister_notify - Unregister notifier callback for PD events.
+ * @nb: Notifier block pointer to unregister
+ *
+ * Unregister a notifier callback that was previously registered with
+ * cros_usbpd_register_notify().
+ */
+void cros_usbpd_unregister_notify(struct notifier_block *nb)
+{
+     blocking_notifier_chain_unregister(&cros_usbpd_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(cros_usbpd_unregister_notify);
+
+#ifdef CONFIG_ACPI
+
+static int cros_usbpd_notify_add_acpi(struct acpi_device *adev)
+{
+     return 0;
+}
+
+static void cros_usbpd_notify_acpi(struct acpi_device *adev, u32 event)
+{
+     blocking_notifier_call_chain(&cros_usbpd_notifier_list, event, NULL);
+}
+
+static const struct acpi_device_id cros_usbpd_notify_acpi_device_ids[] = {
+     { ACPI_DRV_NAME, 0 },
+     { }
+};
+MODULE_DEVICE_TABLE(acpi, cros_usbpd_notify_acpi_device_ids);
+
+static struct acpi_driver cros_usbpd_notify_acpi_driver = {
+     .name = DRV_NAME,
+     .class = DRV_NAME,
+     .ids = cros_usbpd_notify_acpi_device_ids,
+     .ops = {
+             .add = cros_usbpd_notify_add_acpi,
+             .notify = cros_usbpd_notify_acpi,
+     },
+};
+module_acpi_driver(cros_usbpd_notify_acpi_driver);
+
+#endif /* CONFIG_ACPI */
+
+#ifdef CONFIG_OF
+
+static int cros_usbpd_notify_plat(struct notifier_block *nb,
+             unsigned long queued_during_suspend, void *data)
+{
+     struct cros_ec_device *ec_dev = (struct cros_ec_device *)data;
+     u32 host_event = cros_ec_get_host_event(ec_dev);
+
+     if (!host_event)
+             return NOTIFY_BAD;
+
+     if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU)) {
+             blocking_notifier_call_chain(&cros_usbpd_notifier_list,
+                             host_event, NULL);
+             return NOTIFY_OK;
+     }
+     return NOTIFY_DONE;
+}
+
+static int cros_usbpd_notify_probe_plat(struct platform_device *pdev)
+{
+     struct device *dev = &pdev->dev;
+     struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent);
+     struct notifier_block *nb;
+     int ret;
+
+     nb = devm_kzalloc(dev, sizeof(*nb), GFP_KERNEL);
+     if (!nb)
+             return -ENOMEM;
+
+     nb->notifier_call = cros_usbpd_notify_plat;
+     dev_set_drvdata(dev, nb);
+
+     ret = blocking_notifier_chain_register(&ecdev->ec_dev->event_notifier,
+                                             nb);
+     if (ret < 0) {
+             dev_err(dev, "Failed to register notifier\n");
+             return ret;
+     }
+
+     return 0;
+}
+
+static int cros_usbpd_notify_remove_plat(struct platform_device *pdev)
+{
+     struct device *dev = &pdev->dev;
+     struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent);
+     struct notifier_block *nb =
+             (struct notifier_block *)dev_get_drvdata(dev);
+
+     blocking_notifier_chain_unregister(&ecdev->ec_dev->event_notifier,
+                     nb);
+
+     return 0;
+}
+
+static struct platform_driver cros_usbpd_notify_plat_driver = {
+     .driver = {
+             .name = DRV_NAME,
+     },
+     .probe = cros_usbpd_notify_probe_plat,
+     .remove = cros_usbpd_notify_remove_plat,
+};
+module_platform_driver(cros_usbpd_notify_plat_driver);
+
+#endif /* CONFIG_OF */
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ChromeOS power delivery notifier device");
+MODULE_AUTHOR("Jon Flatley <[email protected]>");
+MODULE_ALIAS("platform:" DRV_NAME);

include/linux/platform_data/cros_usbpd_notify.h new file +17 -1

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@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ChromeOS EC Power Delivery Notifier Driver
+ *
+ * Copyright 2020 Google LLC
+ */
+
+#ifndef __LINUX_PLATFORM_DATA_CROS_USBPD_NOTIFY_H
+#define __LINUX_PLATFORM_DATA_CROS_USBPD_NOTIFY_H
+
+#include <linux/notifier.h>
+
+int cros_usbpd_register_notify(struct notifier_block *nb);
+
+void cros_usbpd_unregister_notify(struct notifier_block *nb);
+
+#endif  /* __LINUX_PLATFORM_DATA_CROS_USBPD_NOTIFY_H */
--

Quoted 2 lines

2.25.0.341.g760bfbb309-goog

--
Benson Leung
Staff Software Engineer
Chrome OS Kernel
Google Inc.
[email protected]
Chromium OS Project
[email protected]