[PATCH v2 0/3] platform/chrome: notify: Use PD_HOST_EVENT_STATUS

[PATCH v2 0/3] platform/chrome: notify: Use PD_HOST_EVENT_STATUS

[Prashant Malani]

This series improves the PD notifier driver to get the
EC_CMD_PD_HOST_EVENT_STATUS bits from the Chrome EC, and send those to
the notifier listeners. Earlier, the "event" param of the notifier was
always being hard-coded to a single value (corresponding to PD_MCU
events on ACPI and DT platforms) which wasn't of much use to the
listeners.

Changes in v2:
- Fixed unnecessary error checks.
- Removed extraneous dev_info prints about device registration.
- Rixed pd_command() return codes to be standard Linux error codes.

v1: https://lkml.org/lkml/2020/3/12/287

Prashant Malani (3):
  platform/chrome: notify: Add driver data struct
  platform/chrome: notify: Amend ACPI driver to plat
  platform/chrome: notify: Pull PD_HOST_EVENT status

 drivers/platform/chrome/cros_usbpd_notify.c | 183 +++++++++++++++++---
 1 file changed, 160 insertions(+), 23 deletions(-)

-- 
2.25.1.481.gfbce0eb801-goog

[PATCH v2 1/3] platform/chrome: notify: Add driver data struct

[Prashant Malani]

Introduce a device driver data structure, cros_usbpd_notify_data, in
which we can store the notifier block object and pointers to the struct
cros_ec_device and struct device objects.

This will make it more convenient to access these pointers when
executing both platform and ACPI callbacks.

Signed-off-by: Prashant Malani <pmalani@chromium.org>
---

Changes in v2:
- Removed unnecessary dev_info print at the end of probe.

 drivers/platform/chrome/cros_usbpd_notify.c | 28 ++++++++++++++-------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/drivers/platform/chrome/cros_usbpd_notify.c b/drivers/platform/chrome/cros_usbpd_notify.c
index 3851bbd6e9a39..99cc245354ae7 100644
--- a/drivers/platform/chrome/cros_usbpd_notify.c
+++ b/drivers/platform/chrome/cros_usbpd_notify.c
@@ -16,6 +16,12 @@
 
 static BLOCKING_NOTIFIER_HEAD(cros_usbpd_notifier_list);
 
+struct cros_usbpd_notify_data {
+	struct device *dev;
+	struct cros_ec_device *ec;
+	struct notifier_block nb;
+};
+
 /**
  * cros_usbpd_register_notify - Register a notifier callback for PD events.
  * @nb: Notifier block pointer to register
@@ -98,18 +104,21 @@ 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;
+	struct cros_usbpd_notify_data *pdnotify;
 	int ret;
 
-	nb = devm_kzalloc(dev, sizeof(*nb), GFP_KERNEL);
-	if (!nb)
+	pdnotify = devm_kzalloc(dev, sizeof(*pdnotify), GFP_KERNEL);
+	if (!pdnotify)
 		return -ENOMEM;
 
-	nb->notifier_call = cros_usbpd_notify_plat;
-	dev_set_drvdata(dev, nb);
+	pdnotify->dev = dev;
+	pdnotify->ec = ecdev->ec_dev;
+	pdnotify->nb.notifier_call = cros_usbpd_notify_plat;
+
+	dev_set_drvdata(dev, pdnotify);
 
 	ret = blocking_notifier_chain_register(&ecdev->ec_dev->event_notifier,
-					       nb);
+					       &pdnotify->nb);
 	if (ret < 0) {
 		dev_err(dev, "Failed to register notifier\n");
 		return ret;
@@ -122,10 +131,11 @@ 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);
+	struct cros_usbpd_notify_data *pdnotify =
+		(struct cros_usbpd_notify_data *)dev_get_drvdata(dev);
 
-	blocking_notifier_chain_unregister(&ecdev->ec_dev->event_notifier, nb);
+	blocking_notifier_chain_unregister(&ecdev->ec_dev->event_notifier,
+					   &pdnotify->nb);
 
 	return 0;
 }
-- 
2.25.1.481.gfbce0eb801-goog

[PATCH v2 2/3] platform/chrome: notify: Amend ACPI driver to plat

[Prashant Malani]

Convert the ACPI driver into the equivalent platform driver, with the
same ACPI match table as before. This allows the device driver to access
the parent platform EC device and its cros_ec_device struct, which will
be required to communicate with the EC to pull PD Host event information
from it.

Also change the ACPI driver name to "cros-usbpd-notify-acpi" so that
there is no confusion between it and the "regular" platform driver on
platforms that have both CONFIG_ACPI and CONFIG_OF enabled.

Signed-off-by: Prashant Malani <pmalani@chromium.org>
---

Changes in v2:
- Removed unrequired adev pointer checks, and a dev_info print.

 drivers/platform/chrome/cros_usbpd_notify.c | 71 +++++++++++++++++----
 1 file changed, 59 insertions(+), 12 deletions(-)

diff --git a/drivers/platform/chrome/cros_usbpd_notify.c b/drivers/platform/chrome/cros_usbpd_notify.c
index 99cc245354ae7..5507d93c0ce7b 100644
--- a/drivers/platform/chrome/cros_usbpd_notify.c
+++ b/drivers/platform/chrome/cros_usbpd_notify.c
@@ -12,6 +12,7 @@
 #include <linux/platform_device.h>
 
 #define DRV_NAME "cros-usbpd-notify"
+#define DRV_NAME_PLAT_ACPI "cros-usbpd-notify-acpi"
 #define ACPI_DRV_NAME "GOOG0003"
 
 static BLOCKING_NOTIFIER_HEAD(cros_usbpd_notifier_list);
@@ -54,14 +55,61 @@ EXPORT_SYMBOL_GPL(cros_usbpd_unregister_notify);
 
 #ifdef CONFIG_ACPI
 
-static int cros_usbpd_notify_add_acpi(struct acpi_device *adev)
+static void cros_usbpd_notify_acpi(acpi_handle device, u32 event, void *data)
 {
+	blocking_notifier_call_chain(&cros_usbpd_notifier_list, event, NULL);
+}
+
+static int cros_usbpd_notify_probe_acpi(struct platform_device *pdev)
+{
+	struct cros_usbpd_notify_data *pdnotify;
+	struct device *dev = &pdev->dev;
+	struct acpi_device *adev;
+	struct cros_ec_device *ec_dev;
+	acpi_status status;
+
+	adev = ACPI_COMPANION(dev);
+
+	pdnotify = devm_kzalloc(dev, sizeof(*pdnotify), GFP_KERNEL);
+	if (!pdnotify)
+		return -ENOMEM;
+
+	/* Get the EC device pointer needed to talk to the EC. */
+	ec_dev = dev_get_drvdata(dev->parent);
+	if (!ec_dev) {
+		/*
+		 * We continue even for older devices which don't have the
+		 * correct device heirarchy, namely, GOOG0003 is a child
+		 * of GOOG0004.
+		 */
+		dev_warn(dev, "Couldn't get Chrome EC device pointer.\n");
+	}
+
+	pdnotify->dev = dev;
+	pdnotify->ec = ec_dev;
+
+	status = acpi_install_notify_handler(adev->handle,
+					     ACPI_ALL_NOTIFY,
+					     cros_usbpd_notify_acpi,
+					     pdnotify);
+	if (ACPI_FAILURE(status)) {
+		dev_warn(dev, "Failed to register notify handler %08x\n",
+			 status);
+		return -EINVAL;
+	}
+
 	return 0;
 }
 
-static void cros_usbpd_notify_acpi(struct acpi_device *adev, u32 event)
+static int cros_usbpd_notify_remove_acpi(struct platform_device *pdev)
 {
-	blocking_notifier_call_chain(&cros_usbpd_notifier_list, event, NULL);
+	struct device *dev = &pdev->dev;
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+
+	acpi_remove_notify_handler(adev->handle, ACPI_ALL_NOTIFY,
+				   cros_usbpd_notify_acpi);
+
+	return 0;
 }
 
 static const struct acpi_device_id cros_usbpd_notify_acpi_device_ids[] = {
@@ -70,14 +118,13 @@ static const struct acpi_device_id cros_usbpd_notify_acpi_device_ids[] = {
 };
 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,
+static struct platform_driver cros_usbpd_notify_acpi_driver = {
+	.driver = {
+		.name = DRV_NAME_PLAT_ACPI,
+		.acpi_match_table = cros_usbpd_notify_acpi_device_ids,
 	},
+	.probe = cros_usbpd_notify_probe_acpi,
+	.remove = cros_usbpd_notify_remove_acpi,
 };
 
 #endif /* CONFIG_ACPI */
@@ -157,7 +204,7 @@ static int __init cros_usbpd_notify_init(void)
 		return ret;
 
 #ifdef CONFIG_ACPI
-	acpi_bus_register_driver(&cros_usbpd_notify_acpi_driver);
+	platform_driver_register(&cros_usbpd_notify_acpi_driver);
 #endif
 	return 0;
 }
@@ -165,7 +212,7 @@ static int __init cros_usbpd_notify_init(void)
 static void __exit cros_usbpd_notify_exit(void)
 {
 #ifdef CONFIG_ACPI
-	acpi_bus_unregister_driver(&cros_usbpd_notify_acpi_driver);
+	platform_driver_unregister(&cros_usbpd_notify_acpi_driver);
 #endif
 	platform_driver_unregister(&cros_usbpd_notify_plat_driver);
 }
-- 
2.25.1.481.gfbce0eb801-goog

[PATCH v2 3/3] platform/chrome: notify: Pull PD_HOST_EVENT status

[Prashant Malani]

Read the PD host even status from the EC and send that to the notifier
listeners, for more fine-grained event information.

Signed-off-by: Prashant Malani <pmalani@chromium.org>
---

Changes in v2:
- Fixed variable declaration ordering.
- Updated cros_ec_pd_command() to use standard Linux error codes.

 drivers/platform/chrome/cros_usbpd_notify.c | 86 ++++++++++++++++++++-
 1 file changed, 83 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/chrome/cros_usbpd_notify.c b/drivers/platform/chrome/cros_usbpd_notify.c
index 5507d93c0ce7b..59df762b5e6d7 100644
--- a/drivers/platform/chrome/cros_usbpd_notify.c
+++ b/drivers/platform/chrome/cros_usbpd_notify.c
@@ -53,11 +53,90 @@ void cros_usbpd_unregister_notify(struct notifier_block *nb)
 }
 EXPORT_SYMBOL_GPL(cros_usbpd_unregister_notify);
 
+/**
+ * cros_ec_pd_command - Send a command to the EC.
+ *
+ * @ec_dev: EC device
+ * @command: EC command
+ * @outdata: EC command output data
+ * @outsize: Size of outdata
+ * @indata: EC command input data
+ * @insize: Size of indata
+ *
+ * Return: >= 0 on success, negative error number on failure.
+ */
+static int cros_ec_pd_command(struct cros_ec_device *ec_dev,
+			      int command,
+			      uint8_t *outdata,
+			      int outsize,
+			      uint8_t *indata,
+			      int insize)
+{
+	struct cros_ec_command *msg;
+	int ret;
+
+	msg = kzalloc(sizeof(*msg) + max(insize, outsize), GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	msg->command = command;
+	msg->outsize = outsize;
+	msg->insize = insize;
+
+	if (outsize)
+		memcpy(msg->data, outdata, outsize);
+
+	ret = cros_ec_cmd_xfer_status(ec_dev, msg);
+	if (ret < 0)
+		goto error;
+
+	if (insize)
+		memcpy(indata, msg->data, insize);
+error:
+	kfree(msg);
+	return ret;
+}
+
+static void cros_usbpd_get_event_and_notify(struct device  *dev,
+					    struct cros_ec_device *ec_dev)
+{
+	struct ec_response_host_event_status host_event_status;
+	u32 event = 0;
+	int ret;
+
+	/*
+	 * We still send a 0 event out to older devices which don't
+	 * have the updated device heirarchy.
+	 */
+	if (!ec_dev) {
+		dev_dbg(dev,
+			"EC device inaccessible; sending 0 event status.\n");
+		goto send_notify;
+	}
+
+	/* Check for PD host events on EC. */
+	ret = cros_ec_pd_command(ec_dev, EC_CMD_PD_HOST_EVENT_STATUS,
+				 NULL, 0,
+				 (uint8_t *)&host_event_status,
+				 sizeof(host_event_status));
+	if (ret < 0) {
+		dev_warn(dev, "Can't get host event status (err: %d)\n", ret);
+		goto send_notify;
+	}
+
+	event = host_event_status.status;
+
+send_notify:
+	blocking_notifier_call_chain(&cros_usbpd_notifier_list, event, NULL);
+}
+
 #ifdef CONFIG_ACPI
 
 static void cros_usbpd_notify_acpi(acpi_handle device, u32 event, void *data)
 {
-	blocking_notifier_call_chain(&cros_usbpd_notifier_list, event, NULL);
+	struct cros_usbpd_notify_data *pdnotify = data;
+
+	cros_usbpd_get_event_and_notify(pdnotify->dev, pdnotify->ec);
 }
 
 static int cros_usbpd_notify_probe_acpi(struct platform_device *pdev)
@@ -133,6 +212,8 @@ static int cros_usbpd_notify_plat(struct notifier_block *nb,
 				  unsigned long queued_during_suspend,
 				  void *data)
 {
+	struct cros_usbpd_notify_data *pdnotify = container_of(nb,
+			struct cros_usbpd_notify_data, nb);
 	struct cros_ec_device *ec_dev = (struct cros_ec_device *)data;
 	u32 host_event = cros_ec_get_host_event(ec_dev);
 
@@ -140,8 +221,7 @@ static int cros_usbpd_notify_plat(struct notifier_block *nb,
 		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);
+		cros_usbpd_get_event_and_notify(pdnotify->dev, ec_dev);
 		return NOTIFY_OK;
 	}
 	return NOTIFY_DONE;
-- 
2.25.1.481.gfbce0eb801-goog

Re: [PATCH v2 0/3] platform/chrome: notify: Use PD_HOST_EVENT_STATUS

[Enric Balletbo i Serra]

Hi Prashant,

On 16/3/20 9:28, Prashant Malani wrote:
> This series improves the PD notifier driver to get the
> EC_CMD_PD_HOST_EVENT_STATUS bits from the Chrome EC, and send those to
> the notifier listeners. Earlier, the "event" param of the notifier was
> always being hard-coded to a single value (corresponding to PD_MCU
> events on ACPI and DT platforms) which wasn't of much use to the
> listeners.
> 
> Changes in v2:
> - Fixed unnecessary error checks.
> - Removed extraneous dev_info prints about device registration.
> - Rixed pd_command() return codes to be standard Linux error codes.
> 
> v1: https://lkml.org/lkml/2020/3/12/287
> 
> Prashant Malani (3):
>   platform/chrome: notify: Add driver data struct
>   platform/chrome: notify: Amend ACPI driver to plat
>   platform/chrome: notify: Pull PD_HOST_EVENT status
> 
>  drivers/platform/chrome/cros_usbpd_notify.c | 183 +++++++++++++++++---
>  1 file changed, 160 insertions(+), 23 deletions(-)
> 

Queued all for 5.7. Thanks.

~ Enric