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* [PATCH v10 0/2] usb: typec: Implement UCSI driver for ChromeOS
@ 2024-12-04 19:48 Łukasz Bartosik
  2024-12-04 19:48 ` [PATCH v10 1/2] platform/chrome: Update ChromeOS EC header for UCSI Łukasz Bartosik
  2024-12-04 19:49 ` [PATCH v10 2/2] usb: typec: ucsi: Implement ChromeOS UCSI driver Łukasz Bartosik
  0 siblings, 2 replies; 6+ messages in thread
From: Łukasz Bartosik @ 2024-12-04 19:48 UTC (permalink / raw)
  To: Heikki Krogerus, Greg Kroah-Hartman, Benson Leung,
	Dmitry Baryshkov
  Cc: Abhishek Pandit-Subedi, Jameson Thies, Pavan Holla, Tzung-Bi Shih,
	linux-usb, chrome-platform

This series implements a UCSI ChromeOS EC transport driver. 
The ChromeOS EC is expected to implement UCSI Platform Policy
Manager (PPM).

---
Changes in v10:
- Added cancel_delayed_work() in the cros_ucsi_suspend() in order
to prevent premature wake up during suspend.
- Added cancel_delayed_work() in the cros_ucsi_destroy() as well.
- Link to v9: https://lore.kernel.org/linux-usb/20241203142314.3892422-1-ukaszb@chromium.org/

Changes in v9:
- Squash "usb: typec: cros_ec_ucsi: Recover from write timeouts" commit
into "usb: typec: ucsi: Implement ChromeOS UCSI driver".
- Replaced out label in cros_ucsi_sync_control() with switch statement.
- Link to v8: https://lore.kernel.org/linux-usb/20241128232035.1525978-1-ukaszb@chromium.org/ 

Changes in v8:
- Set .sync_control in cros_ucsi_ops struct to point
to ucsi_sync_control_common().
- Added explanation why complete() is used instead of resume()
in cros_ucsi_pm_ops struct.
- Updated s/miliseconds/milliseconds/.
- Link to v7: https://lore.kernel.org/linux-usb/20241115155234.1587589-1-ukaszb@chromium.org/ 

Changes in v7:
- Dropped the following commits for now as I want to focus
on upstreaming cros_ec_ucsi driver first. Then I will get
back to the topic of trace events and netlink:
  "usb: typec: cros_ec_ucsi: Add trace events"
  "usb: typec: cros_ec_ucsi: Add netlink"
- Squashed "usb: typec: cros_ec_ucsi: Use complete instead of resume"
into "usb: typec: ucsi: Implement ChromeOS UCSI driver".
- Added "usb: typec: cros_ec_ucsi: Recover from write timeouts" commmit.
- Added usage of common functins ucsi_sync_control_common()
and ucsi_notify_common().
- Commits:
  "platform/chrome: Update EC feature flags"
  "mfd: cros_ec: Load cros_ec_ucsi on supported ECs"
  "mfd: cros_ec: Don't load charger with UCSI"
landed in the tree https://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd.git/log/?h=for-mfd-next    
- Link to v6: https://lore.kernel.org/linux-usb/20240910101527.603452-1-ukaszb@chromium.org

Changes in v6:
- Reverted to type names uint*_t in cros_ec_commands.h in order 
to be consistent with type names used in other parts of the file.
- Updated comments in cros_ec_commands.h related to UCSI.
- Added missing sign-offs.
- Fixed memory leak in cros_ucsi_async_control() by moving
ec_params_ucsi_ppm_set request buffer to stack.
- Replaced cros_ucsi_read with cros_ucsi_read_cci in cros_ucsi_work().
- Updated changes in v5, it was missing information related to
commits addition:
  platform/chrome: Update EC feature flags
  usb: typec: cros_ec_ucsi: Use complete instead of resume
  mfd: cros_ec: Load cros_ec_ucsi on supported ECs
  mfd: cros_ec: Don't load charger with UCSI
- Link to v5: https://lore.kernel.org/r/all/20240903163033.3170815-1-ukaszb@chromium.org/

Changes in v5:
- Increased WRITE_TMO_MS to 5000.
- Replaced DRV_NAME with KBUILD_MODNAME.
- Added comments for WRITE_TMO_MS and MAX_EC_DATA_SIZE defines.
- Refactored cros_ucsi_async_control() to dynamically allocate memory
for a message to EC instead of allocating the message on stack.
- Replaced type names uint*_t with u*.
- Removed ret variable in cros_ucsi_work().
- Updated ucsi_operations interface to align with changes introduced in
  v6.11.
- Replaced test_bit() with test_and_clear_bit() in cros_ucsi_work().
- Updated EC feature flags in commit "platform/chrome: Update EC feature
  flags".
- Added new commit "usb: typec: cros_ec_ucsi: Use complete instead
of resume".
- Added trace events in commit "usb: typec: cros_ec_ucsi: Add trace
  events".
- Added netlink in commit "usb: typec: cros_ec_ucsi: Add netlink"
for debugging and testing puropses.
- Added new commit "mfd: cros_ec: Load cros_ec_ucsi on supported ECs".
- Added new commit "mfd: cros_ec: Don't load charger with UCSI".
- Link to v4: https://lore.kernel.org/all/CAB2FV=6We88NrvN8NZYt8NkMFH9N_ZBGyUWVUpGwPdja2X_+NA@mail.gmail.com/T/

Changes in v4:
- Setup notifications before calling ucsi_register.
- Cancel work before destroying driver data.
- Link to v3: https://lore.kernel.org/r/20240403-public-ucsi-h-v3-0-f848e18c8ed2@chromium.org

Changes in v3:
- Moved driver from platform/chrome to usb/typec/ucsi.
- Used id_table instead of MODULE_ALIAS.
- Split EC header changes into seperate commit.
- Fixes from additional internal reviews and kernel bot warnings.
- Link to v2: https://lore.kernel.org/r/20240325-public-ucsi-h-v2-0-a6d716968bb1@chromium.org

Changes in v2:
- No code or commit message changes.
- Added drivers/platform/chrome maintainers for review.

Pavan Holla (2):
  platform/chrome: Update ChromeOS EC header for UCSI
  usb: typec: ucsi: Implement ChromeOS UCSI driver

 MAINTAINERS                                   |   7 +
 drivers/usb/typec/ucsi/Kconfig                |  13 +
 drivers/usb/typec/ucsi/Makefile               |   1 +
 drivers/usb/typec/ucsi/cros_ec_ucsi.c         | 337 ++++++++++++++++++
 .../linux/platform_data/cros_ec_commands.h    |  28 +-
 5 files changed, 385 insertions(+), 1 deletion(-)
 create mode 100644 drivers/usb/typec/ucsi/cros_ec_ucsi.c

-- 
2.47.0.338.g60cca15819-goog


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v10 1/2] platform/chrome: Update ChromeOS EC header for UCSI
  2024-12-04 19:48 [PATCH v10 0/2] usb: typec: Implement UCSI driver for ChromeOS Łukasz Bartosik
@ 2024-12-04 19:48 ` Łukasz Bartosik
  2024-12-04 19:49 ` [PATCH v10 2/2] usb: typec: ucsi: Implement ChromeOS UCSI driver Łukasz Bartosik
  1 sibling, 0 replies; 6+ messages in thread
From: Łukasz Bartosik @ 2024-12-04 19:48 UTC (permalink / raw)
  To: Heikki Krogerus, Greg Kroah-Hartman, Benson Leung,
	Dmitry Baryshkov
  Cc: Abhishek Pandit-Subedi, Jameson Thies, Pavan Holla, Tzung-Bi Shih,
	linux-usb, chrome-platform

From: Pavan Holla <pholla@chromium.org>

Add EC host commands for reading and writing UCSI structures
in the EC. The corresponding kernel driver is cros-ec-ucsi.

Also update PD events supported by the EC.

Acked-by: Tzung-Bi Shih <tzungbi@kernel.org>
Signed-off-by: Pavan Holla <pholla@chromium.org>
Signed-off-by: Łukasz Bartosik <ukaszb@chromium.org>
---
 .../linux/platform_data/cros_ec_commands.h    | 28 ++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/include/linux/platform_data/cros_ec_commands.h b/include/linux/platform_data/cros_ec_commands.h
index b3c4993e656e..ecf290a0c98f 100644
--- a/include/linux/platform_data/cros_ec_commands.h
+++ b/include/linux/platform_data/cros_ec_commands.h
@@ -5044,8 +5044,11 @@ struct ec_response_pd_status {
 #define PD_EVENT_POWER_CHANGE      BIT(1)
 #define PD_EVENT_IDENTITY_RECEIVED BIT(2)
 #define PD_EVENT_DATA_SWAP         BIT(3)
+#define PD_EVENT_TYPEC             BIT(4)
+#define PD_EVENT_PPM               BIT(5)
+
 struct ec_response_host_event_status {
-	uint32_t status;      /* PD MCU host event status */
+	uint32_t status; /* PD MCU host event status */
 } __ec_align4;
 
 /* Set USB type-C port role and muxes */
@@ -6105,6 +6108,29 @@ struct ec_response_typec_vdm_response {
 
 #undef VDO_MAX_SIZE
 
+/*
+ * UCSI OPM-PPM commands
+ *
+ * These commands are used for communication between OPM and PPM.
+ * Only UCSI3.0 is tested.
+ */
+
+#define EC_CMD_UCSI_PPM_SET 0x0140
+
+/* The data size is stored in the host command protocol header. */
+struct ec_params_ucsi_ppm_set {
+	uint16_t offset;
+	uint8_t data[];
+} __ec_align2;
+
+#define EC_CMD_UCSI_PPM_GET 0x0141
+
+/* For 'GET' sub-commands, data will be returned as a raw payload. */
+struct ec_params_ucsi_ppm_get {
+	uint16_t offset;
+	uint8_t size;
+} __ec_align2;
+
 /*****************************************************************************/
 /* The command range 0x200-0x2FF is reserved for Rotor. */
 
-- 
2.47.0.338.g60cca15819-goog


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH v10 2/2] usb: typec: ucsi: Implement ChromeOS UCSI driver
  2024-12-04 19:48 [PATCH v10 0/2] usb: typec: Implement UCSI driver for ChromeOS Łukasz Bartosik
  2024-12-04 19:48 ` [PATCH v10 1/2] platform/chrome: Update ChromeOS EC header for UCSI Łukasz Bartosik
@ 2024-12-04 19:49 ` Łukasz Bartosik
  2024-12-05 14:48   ` Heikki Krogerus
  2024-12-09 16:48   ` Abhishek Pandit-Subedi
  1 sibling, 2 replies; 6+ messages in thread
From: Łukasz Bartosik @ 2024-12-04 19:49 UTC (permalink / raw)
  To: Heikki Krogerus, Greg Kroah-Hartman, Benson Leung,
	Dmitry Baryshkov
  Cc: Abhishek Pandit-Subedi, Jameson Thies, Pavan Holla, Tzung-Bi Shih,
	linux-usb, chrome-platform

From: Pavan Holla <pholla@chromium.org>

Implementation of a UCSI transport driver for ChromeOS.
This driver will be loaded if the ChromeOS EC implements a PPM.

Signed-off-by: Pavan Holla <pholla@chromium.org>
Co-developed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Co-developed-by: Łukasz Bartosik <ukaszb@chromium.org>
Signed-off-by: Łukasz Bartosik <ukaszb@chromium.org>
---
 MAINTAINERS                           |   7 +
 drivers/usb/typec/ucsi/Kconfig        |  13 +
 drivers/usb/typec/ucsi/Makefile       |   1 +
 drivers/usb/typec/ucsi/cros_ec_ucsi.c | 337 ++++++++++++++++++++++++++
 4 files changed, 358 insertions(+)
 create mode 100644 drivers/usb/typec/ucsi/cros_ec_ucsi.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 1e930c7a58b1..36eebe1ad078 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5452,6 +5452,13 @@ L:	chrome-platform@lists.linux.dev
 S:	Maintained
 F:	drivers/watchdog/cros_ec_wdt.c
 
+CHROMEOS UCSI DRIVER
+M:	Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
+M:	Łukasz Bartosik <ukaszb@chromium.org>
+L:	chrome-platform@lists.linux.dev
+S:	Maintained
+F:	drivers/usb/typec/ucsi/cros_ec_ucsi.c
+
 CHRONTEL CH7322 CEC DRIVER
 M:	Joe Tessler <jrt@google.com>
 L:	linux-media@vger.kernel.org
diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig
index 680e1b87b152..75559601fe8f 100644
--- a/drivers/usb/typec/ucsi/Kconfig
+++ b/drivers/usb/typec/ucsi/Kconfig
@@ -69,6 +69,19 @@ config UCSI_PMIC_GLINK
 	  To compile the driver as a module, choose M here: the module will be
 	  called ucsi_glink.
 
+config CROS_EC_UCSI
+	tristate "UCSI Driver for ChromeOS EC"
+	depends on MFD_CROS_EC_DEV
+	depends on CROS_USBPD_NOTIFY
+	depends on !EXTCON_TCSS_CROS_EC
+	default MFD_CROS_EC_DEV
+	help
+	  This driver enables UCSI support for a ChromeOS EC. The EC is
+	  expected to implement a PPM.
+
+	  To compile the driver as a module, choose M here: the module
+	  will be called cros_ec_ucsi.
+
 config UCSI_LENOVO_YOGA_C630
 	tristate "UCSI Interface Driver for Lenovo Yoga C630"
 	depends on EC_LENOVO_YOGA_C630
diff --git a/drivers/usb/typec/ucsi/Makefile b/drivers/usb/typec/ucsi/Makefile
index aed41d23887b..be98a879104d 100644
--- a/drivers/usb/typec/ucsi/Makefile
+++ b/drivers/usb/typec/ucsi/Makefile
@@ -21,4 +21,5 @@ obj-$(CONFIG_UCSI_ACPI)			+= ucsi_acpi.o
 obj-$(CONFIG_UCSI_CCG)			+= ucsi_ccg.o
 obj-$(CONFIG_UCSI_STM32G0)		+= ucsi_stm32g0.o
 obj-$(CONFIG_UCSI_PMIC_GLINK)		+= ucsi_glink.o
+obj-$(CONFIG_CROS_EC_UCSI)		+= cros_ec_ucsi.o
 obj-$(CONFIG_UCSI_LENOVO_YOGA_C630)	+= ucsi_yoga_c630.o
diff --git a/drivers/usb/typec/ucsi/cros_ec_ucsi.c b/drivers/usb/typec/ucsi/cros_ec_ucsi.c
new file mode 100644
index 000000000000..cd2231d6a0ea
--- /dev/null
+++ b/drivers/usb/typec/ucsi/cros_ec_ucsi.c
@@ -0,0 +1,337 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * UCSI driver for ChromeOS EC
+ *
+ * Copyright 2024 Google LLC.
+ */
+
+#include <linux/container_of.h>
+#include <linux/dev_printk.h>
+#include <linux/jiffies.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_data/cros_ec_commands.h>
+#include <linux/platform_data/cros_usbpd_notify.h>
+#include <linux/platform_data/cros_ec_proto.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+
+#include "ucsi.h"
+
+/*
+ * Maximum size in bytes of a UCSI message between AP and EC
+ */
+#define MAX_EC_DATA_SIZE	256
+
+/*
+ * Maximum time in milliseconds the cros_ec_ucsi driver
+ * will wait for a response to a command or and ack.
+ */
+#define WRITE_TMO_MS		5000
+
+/* Number of times to attempt recovery from a write timeout before giving up. */
+#define WRITE_TMO_CTR_MAX	5
+
+struct cros_ucsi_data {
+	struct device *dev;
+	struct ucsi *ucsi;
+
+	struct cros_ec_device *ec;
+	struct notifier_block nb;
+	struct work_struct work;
+	struct delayed_work write_tmo;
+	int tmo_counter;
+
+	struct completion complete;
+	unsigned long flags;
+};
+
+static int cros_ucsi_read(struct ucsi *ucsi, unsigned int offset, void *val,
+			  size_t val_len)
+{
+	struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi);
+	struct ec_params_ucsi_ppm_get req = {
+		.offset = offset,
+		.size = val_len,
+	};
+	int ret;
+
+	if (val_len > MAX_EC_DATA_SIZE) {
+		dev_err(udata->dev, "Can't read %zu bytes. Too big.", val_len);
+		return -EINVAL;
+	}
+
+	ret = cros_ec_cmd(udata->ec, 0, EC_CMD_UCSI_PPM_GET,
+			  &req, sizeof(req), val, val_len);
+	if (ret < 0) {
+		dev_warn(udata->dev, "Failed to send EC message UCSI_PPM_GET: error=%d", ret);
+		return ret;
+	}
+	return 0;
+}
+
+static int cros_ucsi_read_version(struct ucsi *ucsi, u16 *version)
+{
+	return cros_ucsi_read(ucsi, UCSI_VERSION, version, sizeof(*version));
+}
+
+static int cros_ucsi_read_cci(struct ucsi *ucsi, u32 *cci)
+{
+	return cros_ucsi_read(ucsi, UCSI_CCI, cci, sizeof(*cci));
+}
+
+static int cros_ucsi_read_message_in(struct ucsi *ucsi, void *val,
+				     size_t val_len)
+{
+	return cros_ucsi_read(ucsi, UCSI_MESSAGE_IN, val, val_len);
+}
+
+static int cros_ucsi_async_control(struct ucsi *ucsi, u64 cmd)
+{
+	struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi);
+	u8 ec_buf[sizeof(struct ec_params_ucsi_ppm_set) + sizeof(cmd)];
+	struct ec_params_ucsi_ppm_set *req = (struct ec_params_ucsi_ppm_set *) ec_buf;
+	int ret;
+
+	req->offset = UCSI_CONTROL;
+	memcpy(req->data, &cmd, sizeof(cmd));
+	ret = cros_ec_cmd(udata->ec, 0, EC_CMD_UCSI_PPM_SET,
+			  req, sizeof(ec_buf), NULL, 0);
+	if (ret < 0) {
+		dev_warn(udata->dev, "Failed to send EC message UCSI_PPM_SET: error=%d", ret);
+		return ret;
+	}
+	return 0;
+}
+
+static int cros_ucsi_sync_control(struct ucsi *ucsi, u64 cmd)
+{
+	struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi);
+	int ret;
+
+	ret = ucsi_sync_control_common(ucsi, cmd);
+	switch (ret) {
+	case -EBUSY:
+		/* EC may return -EBUSY if CCI.busy is set.
+		 * Convert this to a timeout.
+		 */
+	case -ETIMEDOUT:
+		/* Schedule recovery attempt when we timeout
+		 * or tried to send a command while still busy.
+		 */
+		cancel_delayed_work_sync(&udata->write_tmo);
+		schedule_delayed_work(&udata->write_tmo,
+				      msecs_to_jiffies(WRITE_TMO_MS));
+		break;
+	case 0:
+		/* Successful write. Cancel any pending recovery work. */
+		cancel_delayed_work_sync(&udata->write_tmo);
+		break;
+	}
+
+	return ret;
+}
+
+struct ucsi_operations cros_ucsi_ops = {
+	.read_version = cros_ucsi_read_version,
+	.read_cci = cros_ucsi_read_cci,
+	.read_message_in = cros_ucsi_read_message_in,
+	.async_control = cros_ucsi_async_control,
+	.sync_control = cros_ucsi_sync_control,
+};
+
+static void cros_ucsi_work(struct work_struct *work)
+{
+	struct cros_ucsi_data *udata = container_of(work, struct cros_ucsi_data, work);
+	u32 cci;
+
+	if (cros_ucsi_read_cci(udata->ucsi, &cci))
+		return;
+
+	ucsi_notify_common(udata->ucsi, cci);
+}
+
+static void cros_ucsi_write_timeout(struct work_struct *work)
+{
+	struct cros_ucsi_data *udata =
+		container_of(work, struct cros_ucsi_data, write_tmo.work);
+	u32 cci;
+	u64 cmd;
+
+	if (cros_ucsi_read(udata->ucsi, UCSI_CCI, &cci, sizeof(cci))) {
+		dev_err(udata->dev,
+			"Reading CCI failed; no write timeout recovery possible.");
+		return;
+	}
+
+	if (cci & UCSI_CCI_BUSY) {
+		udata->tmo_counter++;
+
+		if (udata->tmo_counter <= WRITE_TMO_CTR_MAX)
+			schedule_delayed_work(&udata->write_tmo,
+					      msecs_to_jiffies(WRITE_TMO_MS));
+		else
+			dev_err(udata->dev,
+				"PPM unresponsive - too many write timeouts.");
+
+		return;
+	}
+
+	/* No longer busy means we can reset our timeout counter. */
+	udata->tmo_counter = 0;
+
+	/* Need to ack previous command which may have timed out. */
+	if (cci & UCSI_CCI_COMMAND_COMPLETE) {
+		cmd = UCSI_ACK_CC_CI | UCSI_ACK_COMMAND_COMPLETE;
+		cros_ucsi_async_control(udata->ucsi, &cmd);
+
+		/* Check again after a few seconds that the system has
+		 * recovered to make sure our async write above was successful.
+		 */
+		schedule_delayed_work(&udata->write_tmo,
+				      msecs_to_jiffies(WRITE_TMO_MS));
+		return;
+	}
+
+	/* We recovered from a previous timeout. Treat this as a recovery from
+	 * suspend and call resume.
+	 */
+	ucsi_resume(udata->ucsi);
+}
+
+static int cros_ucsi_event(struct notifier_block *nb,
+			   unsigned long host_event, void *_notify)
+{
+	struct cros_ucsi_data *udata = container_of(nb, struct cros_ucsi_data, nb);
+
+	if (!(host_event & PD_EVENT_PPM))
+		return NOTIFY_OK;
+
+	dev_dbg(udata->dev, "UCSI notification received");
+	flush_work(&udata->work);
+	schedule_work(&udata->work);
+
+	return NOTIFY_OK;
+}
+
+static void cros_ucsi_destroy(struct cros_ucsi_data *udata)
+{
+	cros_usbpd_unregister_notify(&udata->nb);
+	cancel_delayed_work(&udata->write_tmo);
+	cancel_work_sync(&udata->work);
+	ucsi_destroy(udata->ucsi);
+}
+
+static int cros_ucsi_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct cros_ec_dev *ec_data = dev_get_drvdata(dev->parent);
+	struct cros_ucsi_data *udata;
+	int ret;
+
+	udata = devm_kzalloc(dev, sizeof(*udata), GFP_KERNEL);
+	if (!udata)
+		return -ENOMEM;
+
+	udata->dev = dev;
+
+	udata->ec = ec_data->ec_dev;
+	if (!udata->ec) {
+		dev_err(dev, "couldn't find parent EC device");
+		return -ENODEV;
+	}
+
+	platform_set_drvdata(pdev, udata);
+
+	INIT_WORK(&udata->work, cros_ucsi_work);
+	INIT_DELAYED_WORK(&udata->write_tmo, cros_ucsi_write_timeout);
+	init_completion(&udata->complete);
+
+	udata->ucsi = ucsi_create(dev, &cros_ucsi_ops);
+	if (IS_ERR(udata->ucsi)) {
+		dev_err(dev, "failed to allocate UCSI instance");
+		return PTR_ERR(udata->ucsi);
+	}
+
+	ucsi_set_drvdata(udata->ucsi, udata);
+
+	udata->nb.notifier_call = cros_ucsi_event;
+	ret = cros_usbpd_register_notify(&udata->nb);
+	if (ret) {
+		dev_err(dev, "failed to register notifier: error=%d", ret);
+		ucsi_destroy(udata->ucsi);
+		return ret;
+	}
+
+	ret = ucsi_register(udata->ucsi);
+	if (ret) {
+		dev_err(dev, "failed to register UCSI: error=%d", ret);
+		cros_ucsi_destroy(udata);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void cros_ucsi_remove(struct platform_device *dev)
+{
+	struct cros_ucsi_data *udata = platform_get_drvdata(dev);
+
+	ucsi_unregister(udata->ucsi);
+	cros_ucsi_destroy(udata);
+}
+
+static int __maybe_unused cros_ucsi_suspend(struct device *dev)
+{
+	struct cros_ucsi_data *udata = dev_get_drvdata(dev);
+
+	cancel_delayed_work(&udata->write_tmo);
+	cancel_work_sync(&udata->work);
+
+	return 0;
+}
+
+static void __maybe_unused cros_ucsi_complete(struct device *dev)
+{
+	struct cros_ucsi_data *udata = dev_get_drvdata(dev);
+
+	ucsi_resume(udata->ucsi);
+}
+
+/*
+ * UCSI protocol is also used on ChromeOS platforms which reply on
+ * cros_ec_lpc.c driver for communication with embedded controller (EC).
+ * On such platforms communication with the EC is not available until
+ * the .complete() callback of the cros_ec_lpc driver is executed.
+ * For this reason we delay ucsi_resume() until the .complete() stage
+ * otherwise UCSI SET_NOTIFICATION_ENABLE command will fail and we won't
+ * receive any UCSI notifications from the EC where PPM is implemented.
+ */
+static const struct dev_pm_ops cros_ucsi_pm_ops = {
+#ifdef CONFIG_PM_SLEEP
+	.suspend = cros_ucsi_suspend,
+	.complete = cros_ucsi_complete,
+#endif
+};
+
+static const struct platform_device_id cros_ucsi_id[] = {
+	{ KBUILD_MODNAME, 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(platform, cros_ucsi_id);
+
+static struct platform_driver cros_ucsi_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.pm = &cros_ucsi_pm_ops,
+	},
+	.id_table = cros_ucsi_id,
+	.probe = cros_ucsi_probe,
+	.remove = cros_ucsi_remove,
+};
+
+module_platform_driver(cros_ucsi_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("UCSI driver for ChromeOS EC");
-- 
2.47.0.338.g60cca15819-goog


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v10 2/2] usb: typec: ucsi: Implement ChromeOS UCSI driver
  2024-12-04 19:49 ` [PATCH v10 2/2] usb: typec: ucsi: Implement ChromeOS UCSI driver Łukasz Bartosik
@ 2024-12-05 14:48   ` Heikki Krogerus
  2024-12-09 16:48   ` Abhishek Pandit-Subedi
  1 sibling, 0 replies; 6+ messages in thread
From: Heikki Krogerus @ 2024-12-05 14:48 UTC (permalink / raw)
  To: Łukasz Bartosik
  Cc: Greg Kroah-Hartman, Benson Leung, Dmitry Baryshkov,
	Abhishek Pandit-Subedi, Jameson Thies, Pavan Holla, Tzung-Bi Shih,
	linux-usb, chrome-platform

On Wed, Dec 04, 2024 at 07:49:00PM +0000, Łukasz Bartosik wrote:
> From: Pavan Holla <pholla@chromium.org>
> 
> Implementation of a UCSI transport driver for ChromeOS.
> This driver will be loaded if the ChromeOS EC implements a PPM.
> 
> Signed-off-by: Pavan Holla <pholla@chromium.org>
> Co-developed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> Co-developed-by: Łukasz Bartosik <ukaszb@chromium.org>
> Signed-off-by: Łukasz Bartosik <ukaszb@chromium.org>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
>  MAINTAINERS                           |   7 +
>  drivers/usb/typec/ucsi/Kconfig        |  13 +
>  drivers/usb/typec/ucsi/Makefile       |   1 +
>  drivers/usb/typec/ucsi/cros_ec_ucsi.c | 337 ++++++++++++++++++++++++++
>  4 files changed, 358 insertions(+)
>  create mode 100644 drivers/usb/typec/ucsi/cros_ec_ucsi.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 1e930c7a58b1..36eebe1ad078 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -5452,6 +5452,13 @@ L:	chrome-platform@lists.linux.dev
>  S:	Maintained
>  F:	drivers/watchdog/cros_ec_wdt.c
>  
> +CHROMEOS UCSI DRIVER
> +M:	Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> +M:	Łukasz Bartosik <ukaszb@chromium.org>
> +L:	chrome-platform@lists.linux.dev
> +S:	Maintained
> +F:	drivers/usb/typec/ucsi/cros_ec_ucsi.c
> +
>  CHRONTEL CH7322 CEC DRIVER
>  M:	Joe Tessler <jrt@google.com>
>  L:	linux-media@vger.kernel.org
> diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig
> index 680e1b87b152..75559601fe8f 100644
> --- a/drivers/usb/typec/ucsi/Kconfig
> +++ b/drivers/usb/typec/ucsi/Kconfig
> @@ -69,6 +69,19 @@ config UCSI_PMIC_GLINK
>  	  To compile the driver as a module, choose M here: the module will be
>  	  called ucsi_glink.
>  
> +config CROS_EC_UCSI
> +	tristate "UCSI Driver for ChromeOS EC"
> +	depends on MFD_CROS_EC_DEV
> +	depends on CROS_USBPD_NOTIFY
> +	depends on !EXTCON_TCSS_CROS_EC
> +	default MFD_CROS_EC_DEV
> +	help
> +	  This driver enables UCSI support for a ChromeOS EC. The EC is
> +	  expected to implement a PPM.
> +
> +	  To compile the driver as a module, choose M here: the module
> +	  will be called cros_ec_ucsi.
> +
>  config UCSI_LENOVO_YOGA_C630
>  	tristate "UCSI Interface Driver for Lenovo Yoga C630"
>  	depends on EC_LENOVO_YOGA_C630
> diff --git a/drivers/usb/typec/ucsi/Makefile b/drivers/usb/typec/ucsi/Makefile
> index aed41d23887b..be98a879104d 100644
> --- a/drivers/usb/typec/ucsi/Makefile
> +++ b/drivers/usb/typec/ucsi/Makefile
> @@ -21,4 +21,5 @@ obj-$(CONFIG_UCSI_ACPI)			+= ucsi_acpi.o
>  obj-$(CONFIG_UCSI_CCG)			+= ucsi_ccg.o
>  obj-$(CONFIG_UCSI_STM32G0)		+= ucsi_stm32g0.o
>  obj-$(CONFIG_UCSI_PMIC_GLINK)		+= ucsi_glink.o
> +obj-$(CONFIG_CROS_EC_UCSI)		+= cros_ec_ucsi.o
>  obj-$(CONFIG_UCSI_LENOVO_YOGA_C630)	+= ucsi_yoga_c630.o
> diff --git a/drivers/usb/typec/ucsi/cros_ec_ucsi.c b/drivers/usb/typec/ucsi/cros_ec_ucsi.c
> new file mode 100644
> index 000000000000..cd2231d6a0ea
> --- /dev/null
> +++ b/drivers/usb/typec/ucsi/cros_ec_ucsi.c
> @@ -0,0 +1,337 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * UCSI driver for ChromeOS EC
> + *
> + * Copyright 2024 Google LLC.
> + */
> +
> +#include <linux/container_of.h>
> +#include <linux/dev_printk.h>
> +#include <linux/jiffies.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/platform_data/cros_ec_commands.h>
> +#include <linux/platform_data/cros_usbpd_notify.h>
> +#include <linux/platform_data/cros_ec_proto.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/wait.h>
> +
> +#include "ucsi.h"
> +
> +/*
> + * Maximum size in bytes of a UCSI message between AP and EC
> + */
> +#define MAX_EC_DATA_SIZE	256
> +
> +/*
> + * Maximum time in milliseconds the cros_ec_ucsi driver
> + * will wait for a response to a command or and ack.
> + */
> +#define WRITE_TMO_MS		5000
> +
> +/* Number of times to attempt recovery from a write timeout before giving up. */
> +#define WRITE_TMO_CTR_MAX	5
> +
> +struct cros_ucsi_data {
> +	struct device *dev;
> +	struct ucsi *ucsi;
> +
> +	struct cros_ec_device *ec;
> +	struct notifier_block nb;
> +	struct work_struct work;
> +	struct delayed_work write_tmo;
> +	int tmo_counter;
> +
> +	struct completion complete;
> +	unsigned long flags;
> +};
> +
> +static int cros_ucsi_read(struct ucsi *ucsi, unsigned int offset, void *val,
> +			  size_t val_len)
> +{
> +	struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi);
> +	struct ec_params_ucsi_ppm_get req = {
> +		.offset = offset,
> +		.size = val_len,
> +	};
> +	int ret;
> +
> +	if (val_len > MAX_EC_DATA_SIZE) {
> +		dev_err(udata->dev, "Can't read %zu bytes. Too big.", val_len);
> +		return -EINVAL;
> +	}
> +
> +	ret = cros_ec_cmd(udata->ec, 0, EC_CMD_UCSI_PPM_GET,
> +			  &req, sizeof(req), val, val_len);
> +	if (ret < 0) {
> +		dev_warn(udata->dev, "Failed to send EC message UCSI_PPM_GET: error=%d", ret);
> +		return ret;
> +	}
> +	return 0;
> +}
> +
> +static int cros_ucsi_read_version(struct ucsi *ucsi, u16 *version)
> +{
> +	return cros_ucsi_read(ucsi, UCSI_VERSION, version, sizeof(*version));
> +}
> +
> +static int cros_ucsi_read_cci(struct ucsi *ucsi, u32 *cci)
> +{
> +	return cros_ucsi_read(ucsi, UCSI_CCI, cci, sizeof(*cci));
> +}
> +
> +static int cros_ucsi_read_message_in(struct ucsi *ucsi, void *val,
> +				     size_t val_len)
> +{
> +	return cros_ucsi_read(ucsi, UCSI_MESSAGE_IN, val, val_len);
> +}
> +
> +static int cros_ucsi_async_control(struct ucsi *ucsi, u64 cmd)
> +{
> +	struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi);
> +	u8 ec_buf[sizeof(struct ec_params_ucsi_ppm_set) + sizeof(cmd)];
> +	struct ec_params_ucsi_ppm_set *req = (struct ec_params_ucsi_ppm_set *) ec_buf;
> +	int ret;
> +
> +	req->offset = UCSI_CONTROL;
> +	memcpy(req->data, &cmd, sizeof(cmd));
> +	ret = cros_ec_cmd(udata->ec, 0, EC_CMD_UCSI_PPM_SET,
> +			  req, sizeof(ec_buf), NULL, 0);
> +	if (ret < 0) {
> +		dev_warn(udata->dev, "Failed to send EC message UCSI_PPM_SET: error=%d", ret);
> +		return ret;
> +	}
> +	return 0;
> +}
> +
> +static int cros_ucsi_sync_control(struct ucsi *ucsi, u64 cmd)
> +{
> +	struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi);
> +	int ret;
> +
> +	ret = ucsi_sync_control_common(ucsi, cmd);
> +	switch (ret) {
> +	case -EBUSY:
> +		/* EC may return -EBUSY if CCI.busy is set.
> +		 * Convert this to a timeout.
> +		 */
> +	case -ETIMEDOUT:
> +		/* Schedule recovery attempt when we timeout
> +		 * or tried to send a command while still busy.
> +		 */
> +		cancel_delayed_work_sync(&udata->write_tmo);
> +		schedule_delayed_work(&udata->write_tmo,
> +				      msecs_to_jiffies(WRITE_TMO_MS));
> +		break;
> +	case 0:
> +		/* Successful write. Cancel any pending recovery work. */
> +		cancel_delayed_work_sync(&udata->write_tmo);
> +		break;
> +	}
> +
> +	return ret;
> +}
> +
> +struct ucsi_operations cros_ucsi_ops = {
> +	.read_version = cros_ucsi_read_version,
> +	.read_cci = cros_ucsi_read_cci,
> +	.read_message_in = cros_ucsi_read_message_in,
> +	.async_control = cros_ucsi_async_control,
> +	.sync_control = cros_ucsi_sync_control,
> +};
> +
> +static void cros_ucsi_work(struct work_struct *work)
> +{
> +	struct cros_ucsi_data *udata = container_of(work, struct cros_ucsi_data, work);
> +	u32 cci;
> +
> +	if (cros_ucsi_read_cci(udata->ucsi, &cci))
> +		return;
> +
> +	ucsi_notify_common(udata->ucsi, cci);
> +}
> +
> +static void cros_ucsi_write_timeout(struct work_struct *work)
> +{
> +	struct cros_ucsi_data *udata =
> +		container_of(work, struct cros_ucsi_data, write_tmo.work);
> +	u32 cci;
> +	u64 cmd;
> +
> +	if (cros_ucsi_read(udata->ucsi, UCSI_CCI, &cci, sizeof(cci))) {
> +		dev_err(udata->dev,
> +			"Reading CCI failed; no write timeout recovery possible.");
> +		return;
> +	}
> +
> +	if (cci & UCSI_CCI_BUSY) {
> +		udata->tmo_counter++;
> +
> +		if (udata->tmo_counter <= WRITE_TMO_CTR_MAX)
> +			schedule_delayed_work(&udata->write_tmo,
> +					      msecs_to_jiffies(WRITE_TMO_MS));
> +		else
> +			dev_err(udata->dev,
> +				"PPM unresponsive - too many write timeouts.");
> +
> +		return;
> +	}
> +
> +	/* No longer busy means we can reset our timeout counter. */
> +	udata->tmo_counter = 0;
> +
> +	/* Need to ack previous command which may have timed out. */
> +	if (cci & UCSI_CCI_COMMAND_COMPLETE) {
> +		cmd = UCSI_ACK_CC_CI | UCSI_ACK_COMMAND_COMPLETE;
> +		cros_ucsi_async_control(udata->ucsi, &cmd);
> +
> +		/* Check again after a few seconds that the system has
> +		 * recovered to make sure our async write above was successful.
> +		 */
> +		schedule_delayed_work(&udata->write_tmo,
> +				      msecs_to_jiffies(WRITE_TMO_MS));
> +		return;
> +	}
> +
> +	/* We recovered from a previous timeout. Treat this as a recovery from
> +	 * suspend and call resume.
> +	 */
> +	ucsi_resume(udata->ucsi);
> +}
> +
> +static int cros_ucsi_event(struct notifier_block *nb,
> +			   unsigned long host_event, void *_notify)
> +{
> +	struct cros_ucsi_data *udata = container_of(nb, struct cros_ucsi_data, nb);
> +
> +	if (!(host_event & PD_EVENT_PPM))
> +		return NOTIFY_OK;
> +
> +	dev_dbg(udata->dev, "UCSI notification received");
> +	flush_work(&udata->work);
> +	schedule_work(&udata->work);
> +
> +	return NOTIFY_OK;
> +}
> +
> +static void cros_ucsi_destroy(struct cros_ucsi_data *udata)
> +{
> +	cros_usbpd_unregister_notify(&udata->nb);
> +	cancel_delayed_work(&udata->write_tmo);
> +	cancel_work_sync(&udata->work);
> +	ucsi_destroy(udata->ucsi);
> +}
> +
> +static int cros_ucsi_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct cros_ec_dev *ec_data = dev_get_drvdata(dev->parent);
> +	struct cros_ucsi_data *udata;
> +	int ret;
> +
> +	udata = devm_kzalloc(dev, sizeof(*udata), GFP_KERNEL);
> +	if (!udata)
> +		return -ENOMEM;
> +
> +	udata->dev = dev;
> +
> +	udata->ec = ec_data->ec_dev;
> +	if (!udata->ec) {
> +		dev_err(dev, "couldn't find parent EC device");
> +		return -ENODEV;
> +	}
> +
> +	platform_set_drvdata(pdev, udata);
> +
> +	INIT_WORK(&udata->work, cros_ucsi_work);
> +	INIT_DELAYED_WORK(&udata->write_tmo, cros_ucsi_write_timeout);
> +	init_completion(&udata->complete);
> +
> +	udata->ucsi = ucsi_create(dev, &cros_ucsi_ops);
> +	if (IS_ERR(udata->ucsi)) {
> +		dev_err(dev, "failed to allocate UCSI instance");
> +		return PTR_ERR(udata->ucsi);
> +	}
> +
> +	ucsi_set_drvdata(udata->ucsi, udata);
> +
> +	udata->nb.notifier_call = cros_ucsi_event;
> +	ret = cros_usbpd_register_notify(&udata->nb);
> +	if (ret) {
> +		dev_err(dev, "failed to register notifier: error=%d", ret);
> +		ucsi_destroy(udata->ucsi);
> +		return ret;
> +	}
> +
> +	ret = ucsi_register(udata->ucsi);
> +	if (ret) {
> +		dev_err(dev, "failed to register UCSI: error=%d", ret);
> +		cros_ucsi_destroy(udata);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static void cros_ucsi_remove(struct platform_device *dev)
> +{
> +	struct cros_ucsi_data *udata = platform_get_drvdata(dev);
> +
> +	ucsi_unregister(udata->ucsi);
> +	cros_ucsi_destroy(udata);
> +}
> +
> +static int __maybe_unused cros_ucsi_suspend(struct device *dev)
> +{
> +	struct cros_ucsi_data *udata = dev_get_drvdata(dev);
> +
> +	cancel_delayed_work(&udata->write_tmo);
> +	cancel_work_sync(&udata->work);
> +
> +	return 0;
> +}
> +
> +static void __maybe_unused cros_ucsi_complete(struct device *dev)
> +{
> +	struct cros_ucsi_data *udata = dev_get_drvdata(dev);
> +
> +	ucsi_resume(udata->ucsi);
> +}
> +
> +/*
> + * UCSI protocol is also used on ChromeOS platforms which reply on
> + * cros_ec_lpc.c driver for communication with embedded controller (EC).
> + * On such platforms communication with the EC is not available until
> + * the .complete() callback of the cros_ec_lpc driver is executed.
> + * For this reason we delay ucsi_resume() until the .complete() stage
> + * otherwise UCSI SET_NOTIFICATION_ENABLE command will fail and we won't
> + * receive any UCSI notifications from the EC where PPM is implemented.
> + */
> +static const struct dev_pm_ops cros_ucsi_pm_ops = {
> +#ifdef CONFIG_PM_SLEEP
> +	.suspend = cros_ucsi_suspend,
> +	.complete = cros_ucsi_complete,
> +#endif
> +};
> +
> +static const struct platform_device_id cros_ucsi_id[] = {
> +	{ KBUILD_MODNAME, 0 },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(platform, cros_ucsi_id);
> +
> +static struct platform_driver cros_ucsi_driver = {
> +	.driver = {
> +		.name = KBUILD_MODNAME,
> +		.pm = &cros_ucsi_pm_ops,
> +	},
> +	.id_table = cros_ucsi_id,
> +	.probe = cros_ucsi_probe,
> +	.remove = cros_ucsi_remove,
> +};
> +
> +module_platform_driver(cros_ucsi_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("UCSI driver for ChromeOS EC");
> -- 
> 2.47.0.338.g60cca15819-goog

-- 
heikki

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v10 2/2] usb: typec: ucsi: Implement ChromeOS UCSI driver
  2024-12-04 19:49 ` [PATCH v10 2/2] usb: typec: ucsi: Implement ChromeOS UCSI driver Łukasz Bartosik
  2024-12-05 14:48   ` Heikki Krogerus
@ 2024-12-09 16:48   ` Abhishek Pandit-Subedi
  2024-12-10 10:35     ` Łukasz Bartosik
  1 sibling, 1 reply; 6+ messages in thread
From: Abhishek Pandit-Subedi @ 2024-12-09 16:48 UTC (permalink / raw)
  To: Łukasz Bartosik
  Cc: Heikki Krogerus, Greg Kroah-Hartman, Benson Leung,
	Dmitry Baryshkov, Jameson Thies, Pavan Holla, Tzung-Bi Shih,
	linux-usb, chrome-platform

On Wed, Dec 4, 2024 at 11:49 AM Łukasz Bartosik <ukaszb@chromium.org> wrote:
>
> From: Pavan Holla <pholla@chromium.org>
>
> Implementation of a UCSI transport driver for ChromeOS.
> This driver will be loaded if the ChromeOS EC implements a PPM.
>
> Signed-off-by: Pavan Holla <pholla@chromium.org>
> Co-developed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> Co-developed-by: Łukasz Bartosik <ukaszb@chromium.org>
> Signed-off-by: Łukasz Bartosik <ukaszb@chromium.org>
> ---
>  MAINTAINERS                           |   7 +
>  drivers/usb/typec/ucsi/Kconfig        |  13 +
>  drivers/usb/typec/ucsi/Makefile       |   1 +
>  drivers/usb/typec/ucsi/cros_ec_ucsi.c | 337 ++++++++++++++++++++++++++
>  4 files changed, 358 insertions(+)
>  create mode 100644 drivers/usb/typec/ucsi/cros_ec_ucsi.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 1e930c7a58b1..36eebe1ad078 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -5452,6 +5452,13 @@ L:       chrome-platform@lists.linux.dev
>  S:     Maintained
>  F:     drivers/watchdog/cros_ec_wdt.c
>
> +CHROMEOS UCSI DRIVER
> +M:     Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> +M:     Łukasz Bartosik <ukaszb@chromium.org>
> +L:     chrome-platform@lists.linux.dev
> +S:     Maintained
> +F:     drivers/usb/typec/ucsi/cros_ec_ucsi.c
> +
>  CHRONTEL CH7322 CEC DRIVER
>  M:     Joe Tessler <jrt@google.com>
>  L:     linux-media@vger.kernel.org
> diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig
> index 680e1b87b152..75559601fe8f 100644
> --- a/drivers/usb/typec/ucsi/Kconfig
> +++ b/drivers/usb/typec/ucsi/Kconfig
> @@ -69,6 +69,19 @@ config UCSI_PMIC_GLINK
>           To compile the driver as a module, choose M here: the module will be
>           called ucsi_glink.
>
> +config CROS_EC_UCSI
> +       tristate "UCSI Driver for ChromeOS EC"
> +       depends on MFD_CROS_EC_DEV
> +       depends on CROS_USBPD_NOTIFY
> +       depends on !EXTCON_TCSS_CROS_EC
> +       default MFD_CROS_EC_DEV
> +       help
> +         This driver enables UCSI support for a ChromeOS EC. The EC is
> +         expected to implement a PPM.
> +
> +         To compile the driver as a module, choose M here: the module
> +         will be called cros_ec_ucsi.
> +
>  config UCSI_LENOVO_YOGA_C630
>         tristate "UCSI Interface Driver for Lenovo Yoga C630"
>         depends on EC_LENOVO_YOGA_C630
> diff --git a/drivers/usb/typec/ucsi/Makefile b/drivers/usb/typec/ucsi/Makefile
> index aed41d23887b..be98a879104d 100644
> --- a/drivers/usb/typec/ucsi/Makefile
> +++ b/drivers/usb/typec/ucsi/Makefile
> @@ -21,4 +21,5 @@ obj-$(CONFIG_UCSI_ACPI)                       += ucsi_acpi.o
>  obj-$(CONFIG_UCSI_CCG)                 += ucsi_ccg.o
>  obj-$(CONFIG_UCSI_STM32G0)             += ucsi_stm32g0.o
>  obj-$(CONFIG_UCSI_PMIC_GLINK)          += ucsi_glink.o
> +obj-$(CONFIG_CROS_EC_UCSI)             += cros_ec_ucsi.o
>  obj-$(CONFIG_UCSI_LENOVO_YOGA_C630)    += ucsi_yoga_c630.o
> diff --git a/drivers/usb/typec/ucsi/cros_ec_ucsi.c b/drivers/usb/typec/ucsi/cros_ec_ucsi.c
> new file mode 100644
> index 000000000000..cd2231d6a0ea
> --- /dev/null
> +++ b/drivers/usb/typec/ucsi/cros_ec_ucsi.c
> @@ -0,0 +1,337 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * UCSI driver for ChromeOS EC
> + *
> + * Copyright 2024 Google LLC.
> + */
> +
> +#include <linux/container_of.h>
> +#include <linux/dev_printk.h>
> +#include <linux/jiffies.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/platform_data/cros_ec_commands.h>
> +#include <linux/platform_data/cros_usbpd_notify.h>
> +#include <linux/platform_data/cros_ec_proto.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/wait.h>
> +
> +#include "ucsi.h"
> +
> +/*
> + * Maximum size in bytes of a UCSI message between AP and EC
> + */
> +#define MAX_EC_DATA_SIZE       256
> +
> +/*
> + * Maximum time in milliseconds the cros_ec_ucsi driver
> + * will wait for a response to a command or and ack.
> + */
> +#define WRITE_TMO_MS           5000
> +
> +/* Number of times to attempt recovery from a write timeout before giving up. */
> +#define WRITE_TMO_CTR_MAX      5
> +
> +struct cros_ucsi_data {
> +       struct device *dev;
> +       struct ucsi *ucsi;
> +
> +       struct cros_ec_device *ec;
> +       struct notifier_block nb;
> +       struct work_struct work;
> +       struct delayed_work write_tmo;
> +       int tmo_counter;
> +
> +       struct completion complete;
> +       unsigned long flags;
> +};
> +
> +static int cros_ucsi_read(struct ucsi *ucsi, unsigned int offset, void *val,
> +                         size_t val_len)
> +{
> +       struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi);
> +       struct ec_params_ucsi_ppm_get req = {
> +               .offset = offset,
> +               .size = val_len,
> +       };
> +       int ret;
> +
> +       if (val_len > MAX_EC_DATA_SIZE) {
> +               dev_err(udata->dev, "Can't read %zu bytes. Too big.", val_len);
> +               return -EINVAL;
> +       }
> +
> +       ret = cros_ec_cmd(udata->ec, 0, EC_CMD_UCSI_PPM_GET,
> +                         &req, sizeof(req), val, val_len);
> +       if (ret < 0) {
> +               dev_warn(udata->dev, "Failed to send EC message UCSI_PPM_GET: error=%d", ret);
> +               return ret;
> +       }
> +       return 0;
> +}
> +
> +static int cros_ucsi_read_version(struct ucsi *ucsi, u16 *version)
> +{
> +       return cros_ucsi_read(ucsi, UCSI_VERSION, version, sizeof(*version));
> +}
> +
> +static int cros_ucsi_read_cci(struct ucsi *ucsi, u32 *cci)
> +{
> +       return cros_ucsi_read(ucsi, UCSI_CCI, cci, sizeof(*cci));
> +}
> +
> +static int cros_ucsi_read_message_in(struct ucsi *ucsi, void *val,
> +                                    size_t val_len)
> +{
> +       return cros_ucsi_read(ucsi, UCSI_MESSAGE_IN, val, val_len);
> +}
> +
> +static int cros_ucsi_async_control(struct ucsi *ucsi, u64 cmd)
> +{
> +       struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi);
> +       u8 ec_buf[sizeof(struct ec_params_ucsi_ppm_set) + sizeof(cmd)];
> +       struct ec_params_ucsi_ppm_set *req = (struct ec_params_ucsi_ppm_set *) ec_buf;
> +       int ret;
> +
> +       req->offset = UCSI_CONTROL;
> +       memcpy(req->data, &cmd, sizeof(cmd));
> +       ret = cros_ec_cmd(udata->ec, 0, EC_CMD_UCSI_PPM_SET,
> +                         req, sizeof(ec_buf), NULL, 0);
> +       if (ret < 0) {
> +               dev_warn(udata->dev, "Failed to send EC message UCSI_PPM_SET: error=%d", ret);
> +               return ret;
> +       }
> +       return 0;
> +}
> +
> +static int cros_ucsi_sync_control(struct ucsi *ucsi, u64 cmd)
> +{
> +       struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi);
> +       int ret;
> +
> +       ret = ucsi_sync_control_common(ucsi, cmd);
> +       switch (ret) {
> +       case -EBUSY:
> +               /* EC may return -EBUSY if CCI.busy is set.
> +                * Convert this to a timeout.
> +                */
> +       case -ETIMEDOUT:
> +               /* Schedule recovery attempt when we timeout
> +                * or tried to send a command while still busy.
> +                */
> +               cancel_delayed_work_sync(&udata->write_tmo);
> +               schedule_delayed_work(&udata->write_tmo,
> +                                     msecs_to_jiffies(WRITE_TMO_MS));
> +               break;
> +       case 0:
> +               /* Successful write. Cancel any pending recovery work. */
> +               cancel_delayed_work_sync(&udata->write_tmo);
> +               break;
> +       }
> +
> +       return ret;
> +}
> +
> +struct ucsi_operations cros_ucsi_ops = {
> +       .read_version = cros_ucsi_read_version,
> +       .read_cci = cros_ucsi_read_cci,
> +       .read_message_in = cros_ucsi_read_message_in,
> +       .async_control = cros_ucsi_async_control,
> +       .sync_control = cros_ucsi_sync_control,
> +};
> +
> +static void cros_ucsi_work(struct work_struct *work)
> +{
> +       struct cros_ucsi_data *udata = container_of(work, struct cros_ucsi_data, work);
> +       u32 cci;
> +
> +       if (cros_ucsi_read_cci(udata->ucsi, &cci))
> +               return;
> +
> +       ucsi_notify_common(udata->ucsi, cci);
> +}
> +
> +static void cros_ucsi_write_timeout(struct work_struct *work)
> +{
> +       struct cros_ucsi_data *udata =
> +               container_of(work, struct cros_ucsi_data, write_tmo.work);
> +       u32 cci;
> +       u64 cmd;
> +
> +       if (cros_ucsi_read(udata->ucsi, UCSI_CCI, &cci, sizeof(cci))) {
> +               dev_err(udata->dev,
> +                       "Reading CCI failed; no write timeout recovery possible.");
> +               return;
> +       }
> +
> +       if (cci & UCSI_CCI_BUSY) {
> +               udata->tmo_counter++;
> +
> +               if (udata->tmo_counter <= WRITE_TMO_CTR_MAX)
> +                       schedule_delayed_work(&udata->write_tmo,
> +                                             msecs_to_jiffies(WRITE_TMO_MS));
> +               else
> +                       dev_err(udata->dev,
> +                               "PPM unresponsive - too many write timeouts.");
> +
> +               return;
> +       }
> +
> +       /* No longer busy means we can reset our timeout counter. */
> +       udata->tmo_counter = 0;
> +
> +       /* Need to ack previous command which may have timed out. */
> +       if (cci & UCSI_CCI_COMMAND_COMPLETE) {
> +               cmd = UCSI_ACK_CC_CI | UCSI_ACK_COMMAND_COMPLETE;
> +               cros_ucsi_async_control(udata->ucsi, &cmd);
> +
> +               /* Check again after a few seconds that the system has
> +                * recovered to make sure our async write above was successful.
> +                */
> +               schedule_delayed_work(&udata->write_tmo,
> +                                     msecs_to_jiffies(WRITE_TMO_MS));
> +               return;
> +       }
> +
> +       /* We recovered from a previous timeout. Treat this as a recovery from
> +        * suspend and call resume.
> +        */
> +       ucsi_resume(udata->ucsi);
> +}
> +
> +static int cros_ucsi_event(struct notifier_block *nb,
> +                          unsigned long host_event, void *_notify)
> +{
> +       struct cros_ucsi_data *udata = container_of(nb, struct cros_ucsi_data, nb);
> +
> +       if (!(host_event & PD_EVENT_PPM))
> +               return NOTIFY_OK;
> +
> +       dev_dbg(udata->dev, "UCSI notification received");
> +       flush_work(&udata->work);
> +       schedule_work(&udata->work);
> +
> +       return NOTIFY_OK;
> +}
> +
> +static void cros_ucsi_destroy(struct cros_ucsi_data *udata)
> +{
> +       cros_usbpd_unregister_notify(&udata->nb);
> +       cancel_delayed_work(&udata->write_tmo);

Prefer cancel_delayed_work_sync.

> +       cancel_work_sync(&udata->work);
> +       ucsi_destroy(udata->ucsi);
> +}
> +
> +static int cros_ucsi_probe(struct platform_device *pdev)
> +{
> +       struct device *dev = &pdev->dev;
> +       struct cros_ec_dev *ec_data = dev_get_drvdata(dev->parent);
> +       struct cros_ucsi_data *udata;
> +       int ret;
> +
> +       udata = devm_kzalloc(dev, sizeof(*udata), GFP_KERNEL);
> +       if (!udata)
> +               return -ENOMEM;
> +
> +       udata->dev = dev;
> +
> +       udata->ec = ec_data->ec_dev;
> +       if (!udata->ec) {
> +               dev_err(dev, "couldn't find parent EC device");
> +               return -ENODEV;
> +       }
> +
> +       platform_set_drvdata(pdev, udata);
> +
> +       INIT_WORK(&udata->work, cros_ucsi_work);
> +       INIT_DELAYED_WORK(&udata->write_tmo, cros_ucsi_write_timeout);
> +       init_completion(&udata->complete);
> +
> +       udata->ucsi = ucsi_create(dev, &cros_ucsi_ops);
> +       if (IS_ERR(udata->ucsi)) {
> +               dev_err(dev, "failed to allocate UCSI instance");
> +               return PTR_ERR(udata->ucsi);
> +       }
> +
> +       ucsi_set_drvdata(udata->ucsi, udata);
> +
> +       udata->nb.notifier_call = cros_ucsi_event;
> +       ret = cros_usbpd_register_notify(&udata->nb);
> +       if (ret) {
> +               dev_err(dev, "failed to register notifier: error=%d", ret);
> +               ucsi_destroy(udata->ucsi);
> +               return ret;
> +       }
> +
> +       ret = ucsi_register(udata->ucsi);
> +       if (ret) {
> +               dev_err(dev, "failed to register UCSI: error=%d", ret);
> +               cros_ucsi_destroy(udata);
> +               return ret;
> +       }
> +
> +       return 0;
> +}
> +
> +static void cros_ucsi_remove(struct platform_device *dev)
> +{
> +       struct cros_ucsi_data *udata = platform_get_drvdata(dev);
> +
> +       ucsi_unregister(udata->ucsi);
> +       cros_ucsi_destroy(udata);
> +}
> +
> +static int __maybe_unused cros_ucsi_suspend(struct device *dev)
> +{
> +       struct cros_ucsi_data *udata = dev_get_drvdata(dev);
> +
> +       cancel_delayed_work(&udata->write_tmo);

This should probably be cancel_delayed_work_sync. Otherwise, the
writes coming from that work item may cause an interrupt after this
suspend method completes.

> +       cancel_work_sync(&udata->work);
> +
> +       return 0;
> +}
> +
> +static void __maybe_unused cros_ucsi_complete(struct device *dev)
> +{
> +       struct cros_ucsi_data *udata = dev_get_drvdata(dev);
> +
> +       ucsi_resume(udata->ucsi);
> +}
> +
> +/*
> + * UCSI protocol is also used on ChromeOS platforms which reply on
> + * cros_ec_lpc.c driver for communication with embedded controller (EC).
> + * On such platforms communication with the EC is not available until
> + * the .complete() callback of the cros_ec_lpc driver is executed.
> + * For this reason we delay ucsi_resume() until the .complete() stage
> + * otherwise UCSI SET_NOTIFICATION_ENABLE command will fail and we won't
> + * receive any UCSI notifications from the EC where PPM is implemented.
> + */
> +static const struct dev_pm_ops cros_ucsi_pm_ops = {
> +#ifdef CONFIG_PM_SLEEP
> +       .suspend = cros_ucsi_suspend,
> +       .complete = cros_ucsi_complete,
> +#endif
> +};
> +
> +static const struct platform_device_id cros_ucsi_id[] = {
> +       { KBUILD_MODNAME, 0 },
> +       {}
> +};
> +MODULE_DEVICE_TABLE(platform, cros_ucsi_id);
> +
> +static struct platform_driver cros_ucsi_driver = {
> +       .driver = {
> +               .name = KBUILD_MODNAME,
> +               .pm = &cros_ucsi_pm_ops,
> +       },
> +       .id_table = cros_ucsi_id,
> +       .probe = cros_ucsi_probe,
> +       .remove = cros_ucsi_remove,
> +};
> +
> +module_platform_driver(cros_ucsi_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("UCSI driver for ChromeOS EC");
> --
> 2.47.0.338.g60cca15819-goog
>

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v10 2/2] usb: typec: ucsi: Implement ChromeOS UCSI driver
  2024-12-09 16:48   ` Abhishek Pandit-Subedi
@ 2024-12-10 10:35     ` Łukasz Bartosik
  0 siblings, 0 replies; 6+ messages in thread
From: Łukasz Bartosik @ 2024-12-10 10:35 UTC (permalink / raw)
  To: Abhishek Pandit-Subedi, Heikki Krogerus
  Cc: Greg Kroah-Hartman, Benson Leung, Dmitry Baryshkov, Jameson Thies,
	Pavan Holla, Tzung-Bi Shih, linux-usb, chrome-platform

On Mon, Dec 9, 2024 at 5:48 PM Abhishek Pandit-Subedi
<abhishekpandit@chromium.org> wrote:
>
> On Wed, Dec 4, 2024 at 11:49 AM Łukasz Bartosik <ukaszb@chromium.org> wrote:
> >
> > From: Pavan Holla <pholla@chromium.org>
> >
> > Implementation of a UCSI transport driver for ChromeOS.
> > This driver will be loaded if the ChromeOS EC implements a PPM.
> >
> > Signed-off-by: Pavan Holla <pholla@chromium.org>
> > Co-developed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > Co-developed-by: Łukasz Bartosik <ukaszb@chromium.org>
> > Signed-off-by: Łukasz Bartosik <ukaszb@chromium.org>
> > ---
> >  MAINTAINERS                           |   7 +
> >  drivers/usb/typec/ucsi/Kconfig        |  13 +
> >  drivers/usb/typec/ucsi/Makefile       |   1 +
> >  drivers/usb/typec/ucsi/cros_ec_ucsi.c | 337 ++++++++++++++++++++++++++
> >  4 files changed, 358 insertions(+)
> >  create mode 100644 drivers/usb/typec/ucsi/cros_ec_ucsi.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 1e930c7a58b1..36eebe1ad078 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -5452,6 +5452,13 @@ L:       chrome-platform@lists.linux.dev
> >  S:     Maintained
> >  F:     drivers/watchdog/cros_ec_wdt.c
> >
> > +CHROMEOS UCSI DRIVER
> > +M:     Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > +M:     Łukasz Bartosik <ukaszb@chromium.org>
> > +L:     chrome-platform@lists.linux.dev
> > +S:     Maintained
> > +F:     drivers/usb/typec/ucsi/cros_ec_ucsi.c
> > +
> >  CHRONTEL CH7322 CEC DRIVER
> >  M:     Joe Tessler <jrt@google.com>
> >  L:     linux-media@vger.kernel.org
> > diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig
> > index 680e1b87b152..75559601fe8f 100644
> > --- a/drivers/usb/typec/ucsi/Kconfig
> > +++ b/drivers/usb/typec/ucsi/Kconfig
> > @@ -69,6 +69,19 @@ config UCSI_PMIC_GLINK
> >           To compile the driver as a module, choose M here: the module will be
> >           called ucsi_glink.
> >
> > +config CROS_EC_UCSI
> > +       tristate "UCSI Driver for ChromeOS EC"
> > +       depends on MFD_CROS_EC_DEV
> > +       depends on CROS_USBPD_NOTIFY
> > +       depends on !EXTCON_TCSS_CROS_EC
> > +       default MFD_CROS_EC_DEV
> > +       help
> > +         This driver enables UCSI support for a ChromeOS EC. The EC is
> > +         expected to implement a PPM.
> > +
> > +         To compile the driver as a module, choose M here: the module
> > +         will be called cros_ec_ucsi.
> > +
> >  config UCSI_LENOVO_YOGA_C630
> >         tristate "UCSI Interface Driver for Lenovo Yoga C630"
> >         depends on EC_LENOVO_YOGA_C630
> > diff --git a/drivers/usb/typec/ucsi/Makefile b/drivers/usb/typec/ucsi/Makefile
> > index aed41d23887b..be98a879104d 100644
> > --- a/drivers/usb/typec/ucsi/Makefile
> > +++ b/drivers/usb/typec/ucsi/Makefile
> > @@ -21,4 +21,5 @@ obj-$(CONFIG_UCSI_ACPI)                       += ucsi_acpi.o
> >  obj-$(CONFIG_UCSI_CCG)                 += ucsi_ccg.o
> >  obj-$(CONFIG_UCSI_STM32G0)             += ucsi_stm32g0.o
> >  obj-$(CONFIG_UCSI_PMIC_GLINK)          += ucsi_glink.o
> > +obj-$(CONFIG_CROS_EC_UCSI)             += cros_ec_ucsi.o
> >  obj-$(CONFIG_UCSI_LENOVO_YOGA_C630)    += ucsi_yoga_c630.o
> > diff --git a/drivers/usb/typec/ucsi/cros_ec_ucsi.c b/drivers/usb/typec/ucsi/cros_ec_ucsi.c
> > new file mode 100644
> > index 000000000000..cd2231d6a0ea
> > --- /dev/null
> > +++ b/drivers/usb/typec/ucsi/cros_ec_ucsi.c
> > @@ -0,0 +1,337 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * UCSI driver for ChromeOS EC
> > + *
> > + * Copyright 2024 Google LLC.
> > + */
> > +
> > +#include <linux/container_of.h>
> > +#include <linux/dev_printk.h>
> > +#include <linux/jiffies.h>
> > +#include <linux/mod_devicetable.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_data/cros_ec_commands.h>
> > +#include <linux/platform_data/cros_usbpd_notify.h>
> > +#include <linux/platform_data/cros_ec_proto.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/slab.h>
> > +#include <linux/wait.h>
> > +
> > +#include "ucsi.h"
> > +
> > +/*
> > + * Maximum size in bytes of a UCSI message between AP and EC
> > + */
> > +#define MAX_EC_DATA_SIZE       256
> > +
> > +/*
> > + * Maximum time in milliseconds the cros_ec_ucsi driver
> > + * will wait for a response to a command or and ack.
> > + */
> > +#define WRITE_TMO_MS           5000
> > +
> > +/* Number of times to attempt recovery from a write timeout before giving up. */
> > +#define WRITE_TMO_CTR_MAX      5
> > +
> > +struct cros_ucsi_data {
> > +       struct device *dev;
> > +       struct ucsi *ucsi;
> > +
> > +       struct cros_ec_device *ec;
> > +       struct notifier_block nb;
> > +       struct work_struct work;
> > +       struct delayed_work write_tmo;
> > +       int tmo_counter;
> > +
> > +       struct completion complete;
> > +       unsigned long flags;
> > +};
> > +
> > +static int cros_ucsi_read(struct ucsi *ucsi, unsigned int offset, void *val,
> > +                         size_t val_len)
> > +{
> > +       struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi);
> > +       struct ec_params_ucsi_ppm_get req = {
> > +               .offset = offset,
> > +               .size = val_len,
> > +       };
> > +       int ret;
> > +
> > +       if (val_len > MAX_EC_DATA_SIZE) {
> > +               dev_err(udata->dev, "Can't read %zu bytes. Too big.", val_len);
> > +               return -EINVAL;
> > +       }
> > +
> > +       ret = cros_ec_cmd(udata->ec, 0, EC_CMD_UCSI_PPM_GET,
> > +                         &req, sizeof(req), val, val_len);
> > +       if (ret < 0) {
> > +               dev_warn(udata->dev, "Failed to send EC message UCSI_PPM_GET: error=%d", ret);
> > +               return ret;
> > +       }
> > +       return 0;
> > +}
> > +
> > +static int cros_ucsi_read_version(struct ucsi *ucsi, u16 *version)
> > +{
> > +       return cros_ucsi_read(ucsi, UCSI_VERSION, version, sizeof(*version));
> > +}
> > +
> > +static int cros_ucsi_read_cci(struct ucsi *ucsi, u32 *cci)
> > +{
> > +       return cros_ucsi_read(ucsi, UCSI_CCI, cci, sizeof(*cci));
> > +}
> > +
> > +static int cros_ucsi_read_message_in(struct ucsi *ucsi, void *val,
> > +                                    size_t val_len)
> > +{
> > +       return cros_ucsi_read(ucsi, UCSI_MESSAGE_IN, val, val_len);
> > +}
> > +
> > +static int cros_ucsi_async_control(struct ucsi *ucsi, u64 cmd)
> > +{
> > +       struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi);
> > +       u8 ec_buf[sizeof(struct ec_params_ucsi_ppm_set) + sizeof(cmd)];
> > +       struct ec_params_ucsi_ppm_set *req = (struct ec_params_ucsi_ppm_set *) ec_buf;
> > +       int ret;
> > +
> > +       req->offset = UCSI_CONTROL;
> > +       memcpy(req->data, &cmd, sizeof(cmd));
> > +       ret = cros_ec_cmd(udata->ec, 0, EC_CMD_UCSI_PPM_SET,
> > +                         req, sizeof(ec_buf), NULL, 0);
> > +       if (ret < 0) {
> > +               dev_warn(udata->dev, "Failed to send EC message UCSI_PPM_SET: error=%d", ret);
> > +               return ret;
> > +       }
> > +       return 0;
> > +}
> > +
> > +static int cros_ucsi_sync_control(struct ucsi *ucsi, u64 cmd)
> > +{
> > +       struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi);
> > +       int ret;
> > +
> > +       ret = ucsi_sync_control_common(ucsi, cmd);
> > +       switch (ret) {
> > +       case -EBUSY:
> > +               /* EC may return -EBUSY if CCI.busy is set.
> > +                * Convert this to a timeout.
> > +                */
> > +       case -ETIMEDOUT:
> > +               /* Schedule recovery attempt when we timeout
> > +                * or tried to send a command while still busy.
> > +                */
> > +               cancel_delayed_work_sync(&udata->write_tmo);
> > +               schedule_delayed_work(&udata->write_tmo,
> > +                                     msecs_to_jiffies(WRITE_TMO_MS));
> > +               break;
> > +       case 0:
> > +               /* Successful write. Cancel any pending recovery work. */
> > +               cancel_delayed_work_sync(&udata->write_tmo);
> > +               break;
> > +       }
> > +
> > +       return ret;
> > +}
> > +
> > +struct ucsi_operations cros_ucsi_ops = {
> > +       .read_version = cros_ucsi_read_version,
> > +       .read_cci = cros_ucsi_read_cci,
> > +       .read_message_in = cros_ucsi_read_message_in,
> > +       .async_control = cros_ucsi_async_control,
> > +       .sync_control = cros_ucsi_sync_control,
> > +};
> > +
> > +static void cros_ucsi_work(struct work_struct *work)
> > +{
> > +       struct cros_ucsi_data *udata = container_of(work, struct cros_ucsi_data, work);
> > +       u32 cci;
> > +
> > +       if (cros_ucsi_read_cci(udata->ucsi, &cci))
> > +               return;
> > +
> > +       ucsi_notify_common(udata->ucsi, cci);
> > +}
> > +
> > +static void cros_ucsi_write_timeout(struct work_struct *work)
> > +{
> > +       struct cros_ucsi_data *udata =
> > +               container_of(work, struct cros_ucsi_data, write_tmo.work);
> > +       u32 cci;
> > +       u64 cmd;
> > +
> > +       if (cros_ucsi_read(udata->ucsi, UCSI_CCI, &cci, sizeof(cci))) {
> > +               dev_err(udata->dev,
> > +                       "Reading CCI failed; no write timeout recovery possible.");
> > +               return;
> > +       }
> > +
> > +       if (cci & UCSI_CCI_BUSY) {
> > +               udata->tmo_counter++;
> > +
> > +               if (udata->tmo_counter <= WRITE_TMO_CTR_MAX)
> > +                       schedule_delayed_work(&udata->write_tmo,
> > +                                             msecs_to_jiffies(WRITE_TMO_MS));
> > +               else
> > +                       dev_err(udata->dev,
> > +                               "PPM unresponsive - too many write timeouts.");
> > +
> > +               return;
> > +       }
> > +
> > +       /* No longer busy means we can reset our timeout counter. */
> > +       udata->tmo_counter = 0;
> > +
> > +       /* Need to ack previous command which may have timed out. */
> > +       if (cci & UCSI_CCI_COMMAND_COMPLETE) {
> > +               cmd = UCSI_ACK_CC_CI | UCSI_ACK_COMMAND_COMPLETE;
> > +               cros_ucsi_async_control(udata->ucsi, &cmd);
> > +
> > +               /* Check again after a few seconds that the system has
> > +                * recovered to make sure our async write above was successful.
> > +                */
> > +               schedule_delayed_work(&udata->write_tmo,
> > +                                     msecs_to_jiffies(WRITE_TMO_MS));
> > +               return;
> > +       }
> > +
> > +       /* We recovered from a previous timeout. Treat this as a recovery from
> > +        * suspend and call resume.
> > +        */
> > +       ucsi_resume(udata->ucsi);
> > +}
> > +
> > +static int cros_ucsi_event(struct notifier_block *nb,
> > +                          unsigned long host_event, void *_notify)
> > +{
> > +       struct cros_ucsi_data *udata = container_of(nb, struct cros_ucsi_data, nb);
> > +
> > +       if (!(host_event & PD_EVENT_PPM))
> > +               return NOTIFY_OK;
> > +
> > +       dev_dbg(udata->dev, "UCSI notification received");
> > +       flush_work(&udata->work);
> > +       schedule_work(&udata->work);
> > +
> > +       return NOTIFY_OK;
> > +}
> > +
> > +static void cros_ucsi_destroy(struct cros_ucsi_data *udata)
> > +{
> > +       cros_usbpd_unregister_notify(&udata->nb);
> > +       cancel_delayed_work(&udata->write_tmo);
>
> Prefer cancel_delayed_work_sync.
>
> > +       cancel_work_sync(&udata->work);
> > +       ucsi_destroy(udata->ucsi);
> > +}
> > +
> > +static int cros_ucsi_probe(struct platform_device *pdev)
> > +{
> > +       struct device *dev = &pdev->dev;
> > +       struct cros_ec_dev *ec_data = dev_get_drvdata(dev->parent);
> > +       struct cros_ucsi_data *udata;
> > +       int ret;
> > +
> > +       udata = devm_kzalloc(dev, sizeof(*udata), GFP_KERNEL);
> > +       if (!udata)
> > +               return -ENOMEM;
> > +
> > +       udata->dev = dev;
> > +
> > +       udata->ec = ec_data->ec_dev;
> > +       if (!udata->ec) {
> > +               dev_err(dev, "couldn't find parent EC device");
> > +               return -ENODEV;
> > +       }
> > +
> > +       platform_set_drvdata(pdev, udata);
> > +
> > +       INIT_WORK(&udata->work, cros_ucsi_work);
> > +       INIT_DELAYED_WORK(&udata->write_tmo, cros_ucsi_write_timeout);
> > +       init_completion(&udata->complete);
> > +
> > +       udata->ucsi = ucsi_create(dev, &cros_ucsi_ops);
> > +       if (IS_ERR(udata->ucsi)) {
> > +               dev_err(dev, "failed to allocate UCSI instance");
> > +               return PTR_ERR(udata->ucsi);
> > +       }
> > +
> > +       ucsi_set_drvdata(udata->ucsi, udata);
> > +
> > +       udata->nb.notifier_call = cros_ucsi_event;
> > +       ret = cros_usbpd_register_notify(&udata->nb);
> > +       if (ret) {
> > +               dev_err(dev, "failed to register notifier: error=%d", ret);
> > +               ucsi_destroy(udata->ucsi);
> > +               return ret;
> > +       }
> > +
> > +       ret = ucsi_register(udata->ucsi);
> > +       if (ret) {
> > +               dev_err(dev, "failed to register UCSI: error=%d", ret);
> > +               cros_ucsi_destroy(udata);
> > +               return ret;
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +static void cros_ucsi_remove(struct platform_device *dev)
> > +{
> > +       struct cros_ucsi_data *udata = platform_get_drvdata(dev);
> > +
> > +       ucsi_unregister(udata->ucsi);
> > +       cros_ucsi_destroy(udata);
> > +}
> > +
> > +static int __maybe_unused cros_ucsi_suspend(struct device *dev)
> > +{
> > +       struct cros_ucsi_data *udata = dev_get_drvdata(dev);
> > +
> > +       cancel_delayed_work(&udata->write_tmo);
>
> This should probably be cancel_delayed_work_sync. Otherwise, the
> writes coming from that work item may cause an interrupt after this
> suspend method completes.
>

You're right. I need to send the next patchset version then.
Stay tuned ;).

Thanks,
Lukasz

> > +       cancel_work_sync(&udata->work);
> > +
> > +       return 0;
> > +}
> > +
> > +static void __maybe_unused cros_ucsi_complete(struct device *dev)
> > +{
> > +       struct cros_ucsi_data *udata = dev_get_drvdata(dev);
> > +
> > +       ucsi_resume(udata->ucsi);
> > +}
> > +
> > +/*
> > + * UCSI protocol is also used on ChromeOS platforms which reply on
> > + * cros_ec_lpc.c driver for communication with embedded controller (EC).
> > + * On such platforms communication with the EC is not available until
> > + * the .complete() callback of the cros_ec_lpc driver is executed.
> > + * For this reason we delay ucsi_resume() until the .complete() stage
> > + * otherwise UCSI SET_NOTIFICATION_ENABLE command will fail and we won't
> > + * receive any UCSI notifications from the EC where PPM is implemented.
> > + */
> > +static const struct dev_pm_ops cros_ucsi_pm_ops = {
> > +#ifdef CONFIG_PM_SLEEP
> > +       .suspend = cros_ucsi_suspend,
> > +       .complete = cros_ucsi_complete,
> > +#endif
> > +};
> > +
> > +static const struct platform_device_id cros_ucsi_id[] = {
> > +       { KBUILD_MODNAME, 0 },
> > +       {}
> > +};
> > +MODULE_DEVICE_TABLE(platform, cros_ucsi_id);
> > +
> > +static struct platform_driver cros_ucsi_driver = {
> > +       .driver = {
> > +               .name = KBUILD_MODNAME,
> > +               .pm = &cros_ucsi_pm_ops,
> > +       },
> > +       .id_table = cros_ucsi_id,
> > +       .probe = cros_ucsi_probe,
> > +       .remove = cros_ucsi_remove,
> > +};
> > +
> > +module_platform_driver(cros_ucsi_driver);
> > +
> > +MODULE_LICENSE("GPL");
> > +MODULE_DESCRIPTION("UCSI driver for ChromeOS EC");
> > --
> > 2.47.0.338.g60cca15819-goog
> >

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2024-12-10 10:36 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-12-04 19:48 [PATCH v10 0/2] usb: typec: Implement UCSI driver for ChromeOS Łukasz Bartosik
2024-12-04 19:48 ` [PATCH v10 1/2] platform/chrome: Update ChromeOS EC header for UCSI Łukasz Bartosik
2024-12-04 19:49 ` [PATCH v10 2/2] usb: typec: ucsi: Implement ChromeOS UCSI driver Łukasz Bartosik
2024-12-05 14:48   ` Heikki Krogerus
2024-12-09 16:48   ` Abhishek Pandit-Subedi
2024-12-10 10:35     ` Łukasz Bartosik

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