[PATCH 0/3] usb: typec: Implement UCSI driver for ChromeOS

[PATCH 0/3] usb: typec: Implement UCSI driver for ChromeOS

[Pavan Holla]

We are developing a UCSI ChromeOS EC transport driver. The ChromeOS EC
implements a UCSI PPM. This driver is being developed in
drivers/platform/chrome since

1) Most other drivers which depend on ChromeOS EC reside there.

2) Our architecture might undergo a few revisions rapidly, so
   platform/chrome seems like a good place while we finalize our
   design.

This patch series creates a public include/usb/ucsi.h that can be used
by transport drivers outside drivers/usb/typec/ucsi. Then, we use this
interface and ChromeOS EC host commands to send UCSI commands in
drivers/platform/chrome/cros_ec_ucsi.c.

Signed-off-by: Pavan Holla <pholla@chromium.org>
---
Pavan Holla (3):
      usb: typec: ucsi: Provide interface for UCSI transport
      usb: typec: ucsi: Import interface for UCSI transport
      platform/chrome: cros_ec_ucsi: Implement UCSI PDC driver

 MAINTAINERS                                    |   1 +
 drivers/platform/chrome/Kconfig                |  14 ++
 drivers/platform/chrome/Makefile               |   1 +
 drivers/platform/chrome/cros_ec_ucsi.c         | 247 +++++++++++++++++++++++++
 drivers/usb/typec/ucsi/ucsi.h                  |  54 +-----
 include/linux/platform_data/cros_ec_commands.h |  19 ++
 include/linux/usb/ucsi.h                       |  66 +++++++
 7 files changed, 349 insertions(+), 53 deletions(-)
---
base-commit: 4cece764965020c22cff7665b18a012006359095
change-id: 20240325-public-ucsi-h-3ecee4106a58

Best regards,
-- 
Pavan Holla <pholla@chromium.org>

[PATCH 1/3] usb: typec: ucsi: Provide interface for UCSI transport

[Pavan Holla]

The ucsi.h include can be used by driver implementations that
provide transport for UCSI commands.

Signed-off-by: Pavan Holla <pholla@chromium.org>
---
 MAINTAINERS              |  1 +
 include/linux/usb/ucsi.h | 66 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index aa3b947fb080..e799d67a8fa5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22987,6 +22987,7 @@ F:	Documentation/ABI/testing/sysfs-class-typec
 F:	Documentation/driver-api/usb/typec.rst
 F:	drivers/usb/typec/
 F:	include/linux/usb/typec.h
+F:	include/linux/usb/ucsi.h
 
 USB TYPEC INTEL PMC MUX DRIVER
 M:	Heikki Krogerus <heikki.krogerus@linux.intel.com>
diff --git a/include/linux/usb/ucsi.h b/include/linux/usb/ucsi.h
new file mode 100644
index 000000000000..3ec1db968070
--- /dev/null
+++ b/include/linux/usb/ucsi.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __LINUX_USB_UCSI_H
+#define __LINUX_USB_UCSI_H
+
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/types.h>
+
+/* -------------------------------------------------------------------------- */
+
+struct ucsi;
+struct ucsi_altmode;
+
+/* UCSI offsets (Bytes) */
+#define UCSI_VERSION			0
+#define UCSI_CCI			4
+#define UCSI_CONTROL			8
+#define UCSI_MESSAGE_IN			16
+#define UCSI_MESSAGE_OUT		32
+#define UCSIv2_MESSAGE_OUT		272
+
+/* Command Status and Connector Change Indication (CCI) bits */
+#define UCSI_CCI_CONNECTOR(_c_)		(((_c_) & GENMASK(7, 1)) >> 1)
+#define UCSI_CCI_LENGTH(_c_)		(((_c_) & GENMASK(15, 8)) >> 8)
+#define UCSI_CCI_NOT_SUPPORTED		BIT(25)
+#define UCSI_CCI_CANCEL_COMPLETE	BIT(26)
+#define UCSI_CCI_RESET_COMPLETE		BIT(27)
+#define UCSI_CCI_BUSY			BIT(28)
+#define UCSI_CCI_ACK_COMPLETE		BIT(29)
+#define UCSI_CCI_ERROR			BIT(30)
+#define UCSI_CCI_COMMAND_COMPLETE	BIT(31)
+
+/**
+ * struct ucsi_operations - UCSI I/O operations
+ * @read: Read operation
+ * @sync_write: Blocking write operation
+ * @async_write: Non-blocking write operation
+ * @update_altmodes: Squashes duplicate DP altmodes
+ *
+ * Read and write routines for UCSI interface. @sync_write must wait for the
+ * Command Completion Event from the PPM before returning, and @async_write must
+ * return immediately after sending the data to the PPM.
+ */
+struct ucsi_operations {
+	int (*read)(struct ucsi *ucsi, unsigned int offset,
+		    void *val, size_t val_len);
+	int (*sync_write)(struct ucsi *ucsi, unsigned int offset,
+			  const void *val, size_t val_len);
+	int (*async_write)(struct ucsi *ucsi, unsigned int offset,
+			   const void *val, size_t val_len);
+	bool (*update_altmodes)(struct ucsi *ucsi, struct ucsi_altmode *orig,
+				struct ucsi_altmode *updated);
+};
+
+struct ucsi *ucsi_create(struct device *dev, const struct ucsi_operations *ops);
+void ucsi_destroy(struct ucsi *ucsi);
+int ucsi_register(struct ucsi *ucsi);
+void ucsi_unregister(struct ucsi *ucsi);
+int ucsi_resume(struct ucsi *ucsi);
+void *ucsi_get_drvdata(struct ucsi *ucsi);
+void ucsi_set_drvdata(struct ucsi *ucsi, void *data);
+
+void ucsi_connector_change(struct ucsi *ucsi, u8 num);
+
+#endif /* __LINUX_USB_UCSI_H */

-- 
2.44.0.396.g6e790dbe36-goog

[PATCH 2/3] usb: typec: ucsi: Import interface for UCSI transport

[Pavan Holla]

Import include/linux/usb/ucsi.h and remove any duplicate declarations.

Signed-off-by: Pavan Holla <pholla@chromium.org>
---
 drivers/usb/typec/ucsi/ucsi.h | 54 +------------------------------------------
 1 file changed, 1 insertion(+), 53 deletions(-)

diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
index 32daf5f58650..167951538030 100644
--- a/drivers/usb/typec/ucsi/ucsi.h
+++ b/drivers/usb/typec/ucsi/ucsi.h
@@ -10,22 +10,13 @@
 #include <linux/usb/typec.h>
 #include <linux/usb/pd.h>
 #include <linux/usb/role.h>
+#include <linux/usb/ucsi.h>
 #include <asm/unaligned.h>
 
 /* -------------------------------------------------------------------------- */
 
-struct ucsi;
-struct ucsi_altmode;
 struct dentry;
 
-/* UCSI offsets (Bytes) */
-#define UCSI_VERSION			0
-#define UCSI_CCI			4
-#define UCSI_CONTROL			8
-#define UCSI_MESSAGE_IN			16
-#define UCSI_MESSAGE_OUT		32
-#define UCSIv2_MESSAGE_OUT		272
-
 /* UCSI versions */
 #define UCSI_VERSION_1_2	0x0120
 #define UCSI_VERSION_2_0	0x0200
@@ -42,48 +33,6 @@ struct dentry;
  */
 #define UCSI_SPEC_REVISION_TO_BCD(_v_)  (((_v_) + 1) << 8)
 
-/* Command Status and Connector Change Indication (CCI) bits */
-#define UCSI_CCI_CONNECTOR(_c_)		(((_c_) & GENMASK(7, 1)) >> 1)
-#define UCSI_CCI_LENGTH(_c_)		(((_c_) & GENMASK(15, 8)) >> 8)
-#define UCSI_CCI_NOT_SUPPORTED		BIT(25)
-#define UCSI_CCI_CANCEL_COMPLETE	BIT(26)
-#define UCSI_CCI_RESET_COMPLETE		BIT(27)
-#define UCSI_CCI_BUSY			BIT(28)
-#define UCSI_CCI_ACK_COMPLETE		BIT(29)
-#define UCSI_CCI_ERROR			BIT(30)
-#define UCSI_CCI_COMMAND_COMPLETE	BIT(31)
-
-/**
- * struct ucsi_operations - UCSI I/O operations
- * @read: Read operation
- * @sync_write: Blocking write operation
- * @async_write: Non-blocking write operation
- * @update_altmodes: Squashes duplicate DP altmodes
- *
- * Read and write routines for UCSI interface. @sync_write must wait for the
- * Command Completion Event from the PPM before returning, and @async_write must
- * return immediately after sending the data to the PPM.
- */
-struct ucsi_operations {
-	int (*read)(struct ucsi *ucsi, unsigned int offset,
-		    void *val, size_t val_len);
-	int (*sync_write)(struct ucsi *ucsi, unsigned int offset,
-			  const void *val, size_t val_len);
-	int (*async_write)(struct ucsi *ucsi, unsigned int offset,
-			   const void *val, size_t val_len);
-	bool (*update_altmodes)(struct ucsi *ucsi, struct ucsi_altmode *orig,
-				struct ucsi_altmode *updated);
-};
-
-struct ucsi *ucsi_create(struct device *dev, const struct ucsi_operations *ops);
-void ucsi_destroy(struct ucsi *ucsi);
-int ucsi_register(struct ucsi *ucsi);
-void ucsi_unregister(struct ucsi *ucsi);
-void *ucsi_get_drvdata(struct ucsi *ucsi);
-void ucsi_set_drvdata(struct ucsi *ucsi, void *data);
-
-void ucsi_connector_change(struct ucsi *ucsi, u8 num);
-
 /* -------------------------------------------------------------------------- */
 
 /* Commands */
@@ -465,7 +414,6 @@ int ucsi_send_command(struct ucsi *ucsi, u64 command,
 		      void *retval, size_t size);
 
 void ucsi_altmode_update_active(struct ucsi_connector *con);
-int ucsi_resume(struct ucsi *ucsi);
 
 #if IS_ENABLED(CONFIG_POWER_SUPPLY)
 int ucsi_register_port_psy(struct ucsi_connector *con);

-- 
2.44.0.396.g6e790dbe36-goog

[PATCH 3/3] platform/chrome: cros_ec_ucsi: Implement UCSI PDC driver

[Pavan Holla]

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

Signed-off-by: Pavan Holla <pholla@chromium.org>
---
 drivers/platform/chrome/Kconfig                |  14 ++
 drivers/platform/chrome/Makefile               |   1 +
 drivers/platform/chrome/cros_ec_ucsi.c         | 247 +++++++++++++++++++++++++
 include/linux/platform_data/cros_ec_commands.h |  19 ++
 4 files changed, 281 insertions(+)

diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
index 7a83346bfa53..67ab79a6815b 100644
--- a/drivers/platform/chrome/Kconfig
+++ b/drivers/platform/chrome/Kconfig
@@ -238,6 +238,20 @@ config CROS_EC_TYPEC
 	  To compile this driver as a module, choose M here: the module will be
 	  called cros-ec-typec.
 
+config CROS_EC_UCSI
+	tristate "UCSI Driver for ChromeOS EC"
+	depends on MFD_CROS_EC_DEV
+	depends on CROS_USBPD_NOTIFY
+	depends on TYPEC_UCSI
+	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 CROS_HPS_I2C
 	tristate "ChromeOS HPS device"
 	depends on HID && I2C && PM
diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
index 2dcc6ccc2302..85964e165a70 100644
--- a/drivers/platform/chrome/Makefile
+++ b/drivers/platform/chrome/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_CROS_EC_UART)		+= cros_ec_uart.o
 cros_ec_lpcs-objs			:= cros_ec_lpc.o cros_ec_lpc_mec.o
 cros-ec-typec-objs			:= cros_ec_typec.o cros_typec_vdm.o
 obj-$(CONFIG_CROS_EC_TYPEC)		+= cros-ec-typec.o
+obj-$(CONFIG_CROS_EC_UCSI)		+= cros_ec_ucsi.o
 obj-$(CONFIG_CROS_EC_LPC)		+= cros_ec_lpcs.o
 obj-$(CONFIG_CROS_EC_PROTO)		+= cros_ec_proto.o cros_ec_trace.o
 obj-$(CONFIG_CROS_KBD_LED_BACKLIGHT)	+= cros_kbd_led_backlight.o
diff --git a/drivers/platform/chrome/cros_ec_ucsi.c b/drivers/platform/chrome/cros_ec_ucsi.c
new file mode 100644
index 000000000000..9fee300a3d93
--- /dev/null
+++ b/drivers/platform/chrome/cros_ec_ucsi.c
@@ -0,0 +1,247 @@
+// 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/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/usb/ucsi.h>
+#include <linux/wait.h>
+
+#define DRV_NAME "cros-ec-ucsi"
+
+#define MAX_EC_DATA_SIZE 256
+#define WRITE_TMO_MS 500
+
+#define COMMAND_PENDING 1
+#define ACK_PENDING     2
+
+#define UCSI_COMMAND(_cmd_) ((_cmd_) & 0xff)
+#define UCSI_ACK_CC_CI 0x04
+
+struct cros_ucsi_data {
+	struct device *dev;
+	struct ucsi *ucsi;
+
+	struct cros_ec_device *ec;
+	struct notifier_block nb;
+	struct work_struct work;
+
+	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_async_write(struct ucsi *ucsi, unsigned int offset,
+				 const void *val, size_t val_len)
+{
+	struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi);
+	uint8_t ec_buffer[MAX_EC_DATA_SIZE + sizeof(struct ec_params_ucsi_ppm_set)];
+	struct ec_params_ucsi_ppm_set *req = (struct ec_params_ucsi_ppm_set *)ec_buffer;
+	int ret = 0;
+
+	if (val_len > MAX_EC_DATA_SIZE) {
+		dev_err(udata->dev, "Can't write %zu bytes. Too big.", val_len);
+		return -EINVAL;
+	}
+
+	memset(req, 0, sizeof(ec_buffer));
+	req->offset = offset;
+	memcpy(req->data, val, val_len);
+	ret = cros_ec_cmd(udata->ec, 0, EC_CMD_UCSI_PPM_SET,
+			  req, sizeof(struct ec_params_ucsi_ppm_set) + val_len, 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_write(struct ucsi *ucsi, unsigned int offset,
+				const void *val, size_t val_len)
+{
+	struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi);
+	bool ack = UCSI_COMMAND(*(u64 *)val) == UCSI_ACK_CC_CI;
+	int ret;
+
+	if (ack)
+		set_bit(ACK_PENDING, &udata->flags);
+	else
+		set_bit(COMMAND_PENDING, &udata->flags);
+
+	ret = cros_ucsi_async_write(ucsi, offset, val, val_len);
+	if (ret)
+		goto out;
+
+	if (!wait_for_completion_timeout(&udata->complete, WRITE_TMO_MS))
+		ret = -ETIMEDOUT;
+
+out:
+	if (ack)
+		clear_bit(ACK_PENDING, &udata->flags);
+	else
+		clear_bit(COMMAND_PENDING, &udata->flags);
+	return ret;
+}
+
+struct ucsi_operations cros_ucsi_ops = {
+	.read = cros_ucsi_read,
+	.async_write = cros_ucsi_async_write,
+	.sync_write = cros_ucsi_sync_write,
+};
+
+static void cros_ucsi_work(struct work_struct *work)
+{
+	struct cros_ucsi_data *udata = container_of(work, struct cros_ucsi_data, work);
+	u32 cci;
+	int ret;
+
+	ret = cros_ucsi_read(udata->ucsi, UCSI_CCI, &cci, sizeof(cci));
+	if (ret)
+		return;
+
+	if (UCSI_CCI_CONNECTOR(cci))
+		ucsi_connector_change(udata->ucsi, UCSI_CCI_CONNECTOR(cci));
+
+	if (cci & UCSI_CCI_ACK_COMPLETE && test_bit(ACK_PENDING, &udata->flags))
+		complete(&udata->complete);
+	if (cci & UCSI_CCI_COMMAND_COMPLETE &&
+	    test_bit(COMMAND_PENDING, &udata->flags))
+		complete(&udata->complete);
+}
+
+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 int cros_ucsi_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct cros_ucsi_data *udata;
+	int ret;
+
+	udata = devm_kzalloc(dev, sizeof(*udata), GFP_KERNEL);
+	if (!udata)
+		return -ENOMEM;
+
+	udata->dev = dev;
+
+	udata->ec = ((struct cros_ec_dev *) dev_get_drvdata(pdev->dev.parent))->ec_dev;
+	if (!udata->ec) {
+		dev_err(dev, "couldn't find parent EC device\n");
+		return -ENODEV;
+	}
+
+	platform_set_drvdata(pdev, udata);
+
+	INIT_WORK(&udata->work, cros_ucsi_work);
+	init_completion(&udata->complete);
+
+	udata->ucsi = ucsi_create(udata->dev, &cros_ucsi_ops);
+	if (IS_ERR(udata->ucsi)) {
+		dev_err(dev, "failed to allocate UCSI instance\n");
+		return PTR_ERR(udata->ucsi);
+	}
+
+	ucsi_set_drvdata(udata->ucsi, udata);
+
+	ret = ucsi_register(udata->ucsi);
+	if (ret) {
+		ucsi_destroy(udata->ucsi);
+		udata->ucsi = NULL;
+		return ret;
+	}
+
+	udata->nb.notifier_call = cros_ucsi_event;
+	ret = cros_usbpd_register_notify(&udata->nb);
+	return ret;
+}
+
+static int cros_ucsi_remove(struct platform_device *dev)
+{
+	struct cros_ucsi_data *udata = platform_get_drvdata(dev);
+
+	if (udata->ucsi) {
+		ucsi_unregister(udata->ucsi);
+		ucsi_destroy(udata->ucsi);
+		udata->ucsi = NULL;
+	}
+	return 0;
+}
+
+static int cros_ucsi_suspend(struct device *dev)
+{
+	struct cros_ucsi_data *udata = dev_get_drvdata(dev);
+
+	cancel_work_sync(&udata->work);
+
+	return 0;
+}
+
+static int cros_ucsi_resume(struct device *dev)
+{
+	struct cros_ucsi_data *udata = dev_get_drvdata(dev);
+
+	return ucsi_resume(udata->ucsi);
+}
+
+static SIMPLE_DEV_PM_OPS(cros_ucsi_pm_ops, cros_ucsi_suspend,
+			 cros_ucsi_resume);
+
+static struct platform_driver cros_ucsi_driver = {
+	.driver = {
+		.name = DRV_NAME,
+		.pm = &cros_ucsi_pm_ops,
+	},
+	.probe = cros_ucsi_probe,
+	.remove = cros_ucsi_remove,
+};
+
+module_platform_driver(cros_ucsi_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("UCSI driver for ChromeOS EC.");
+MODULE_ALIAS("platform:" DRV_NAME);
diff --git a/include/linux/platform_data/cros_ec_commands.h b/include/linux/platform_data/cros_ec_commands.h
index ecc47d5fe239..39f6f54bbe4c 100644
--- a/include/linux/platform_data/cros_ec_commands.h
+++ b/include/linux/platform_data/cros_ec_commands.h
@@ -4933,6 +4933,7 @@ 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_PPM               BIT(5)
 struct ec_response_host_event_status {
 	uint32_t status;      /* PD MCU host event status */
 } __ec_align4;
@@ -5994,6 +5995,24 @@ struct ec_response_typec_vdm_response {
 
 #undef VDO_MAX_SIZE
 
+/*
+ * Read/write interface for UCSI OPM <-> PPM communication.
+ */
+#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
+
+struct ec_params_ucsi_ppm_get {
+	uint16_t offset;
+	uint8_t size;
+} __ec_align2;
+
 /*****************************************************************************/
 /* The command range 0x200-0x2FF is reserved for Rotor. */
 

-- 
2.44.0.396.g6e790dbe36-goog

Re: [PATCH 2/3] usb: typec: ucsi: Import interface for UCSI transport

[Prashant Malani]

Hi Pavan,

On Mon, Mar 25, 2024 at 4:37 PM Pavan Holla <pholla@chromium.org> wrote:
>
> Import include/linux/usb/ucsi.h and remove any duplicate declarations.
>
> Signed-off-by: Pavan Holla <pholla@chromium.org>

Can you squash Patch 1/3 and this Patch (2/3)? It sounds like an
atomic change that doesn't need two patches.

BR,

-Prashant

Re: [PATCH 3/3] platform/chrome: cros_ec_ucsi: Implement UCSI PDC driver

[Krzysztof Kozlowski]

On 26/03/2024 00:37, Pavan Holla wrote:
> Implementation of transport driver for UCSI. This driver will be used
> if the ChromeOS EC implements a PPM.
> 


> +static struct platform_driver cros_ucsi_driver = {
> +	.driver = {
> +		.name = DRV_NAME,
> +		.pm = &cros_ucsi_pm_ops,
> +	},
> +	.probe = cros_ucsi_probe,
> +	.remove = cros_ucsi_remove,
> +};
> +
> +module_platform_driver(cros_ucsi_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("UCSI driver for ChromeOS EC.");
> +MODULE_ALIAS("platform:" DRV_NAME);

You should not need MODULE_ALIAS() in normal cases. If you need it,
usually it means your device ID table is wrong (e.g. misses either
entries or MODULE_DEVICE_TABLE()). MODULE_ALIAS() is not a substitute
for incomplete ID table.

Using DRV_NAME here brings even more confusion...

Best regards,
Krzysztof

Re: [PATCH 1/3] usb: typec: ucsi: Provide interface for UCSI transport

[Greg Kroah-Hartman]

On Mon, Mar 25, 2024 at 11:37:28PM +0000, Pavan Holla wrote:
> The ucsi.h include can be used by driver implementations that
> provide transport for UCSI commands.
> 
> Signed-off-by: Pavan Holla <pholla@chromium.org>
> ---
>  MAINTAINERS              |  1 +
>  include/linux/usb/ucsi.h | 66 ++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 67 insertions(+)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index aa3b947fb080..e799d67a8fa5 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -22987,6 +22987,7 @@ F:	Documentation/ABI/testing/sysfs-class-typec
>  F:	Documentation/driver-api/usb/typec.rst
>  F:	drivers/usb/typec/
>  F:	include/linux/usb/typec.h
> +F:	include/linux/usb/ucsi.h
>  
>  USB TYPEC INTEL PMC MUX DRIVER
>  M:	Heikki Krogerus <heikki.krogerus@linux.intel.com>
> diff --git a/include/linux/usb/ucsi.h b/include/linux/usb/ucsi.h
> new file mode 100644
> index 000000000000..3ec1db968070
> --- /dev/null
> +++ b/include/linux/usb/ucsi.h
> @@ -0,0 +1,66 @@
> +/* SPDX-License-Identifier: GPL-2.0 */

No copyright line?  I think your employer would not like it if they saw
that :(

Please get review from some internal-to-google developers before
submitting your next version of this series.

thanks,

greg k-h

Re: [PATCH 3/3] platform/chrome: cros_ec_ucsi: Implement UCSI PDC driver

[kernel test robot]

Hi Pavan,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 4cece764965020c22cff7665b18a012006359095]

url:    https://github.com/intel-lab-lkp/linux/commits/Pavan-Holla/usb-typec-ucsi-Provide-interface-for-UCSI-transport/20240326-074003
base:   4cece764965020c22cff7665b18a012006359095
patch link:    https://lore.kernel.org/r/20240325-public-ucsi-h-v1-3-7c7e888edc0a%40chromium.org
patch subject: [PATCH 3/3] platform/chrome: cros_ec_ucsi: Implement UCSI PDC driver
config: alpha-allyesconfig (https://download.01.org/0day-ci/archive/20240327/202403270732.SwdF4BV2-lkp@intel.com/config)
compiler: alpha-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240327/202403270732.SwdF4BV2-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202403270732.SwdF4BV2-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/platform/chrome/cros_ec_ucsi.c:224:12: warning: 'cros_ucsi_resume' defined but not used [-Wunused-function]
     224 | static int cros_ucsi_resume(struct device *dev)
         |            ^~~~~~~~~~~~~~~~
>> drivers/platform/chrome/cros_ec_ucsi.c:215:12: warning: 'cros_ucsi_suspend' defined but not used [-Wunused-function]
     215 | static int cros_ucsi_suspend(struct device *dev)
         |            ^~~~~~~~~~~~~~~~~


vim +/cros_ucsi_resume +224 drivers/platform/chrome/cros_ec_ucsi.c

   214	
 > 215	static int cros_ucsi_suspend(struct device *dev)
   216	{
   217		struct cros_ucsi_data *udata = dev_get_drvdata(dev);
   218	
   219		cancel_work_sync(&udata->work);
   220	
   221		return 0;
   222	}
   223	
 > 224	static int cros_ucsi_resume(struct device *dev)
   225	{
   226		struct cros_ucsi_data *udata = dev_get_drvdata(dev);
   227	
   228		return ucsi_resume(udata->ucsi);
   229	}
   230	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH 1/3] usb: typec: ucsi: Provide interface for UCSI transport

[Pavan Holla]

Hi Greg,

Thanks for the review.

On Tue, Mar 26, 2024 at 2:12 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
> No copyright line?  I think your employer would not like it if they saw
> that :(

My employer ( Google ) does not want me to insert a copyright notice
if third party code
was copied verbatim. I plan to squash commit 1 and commit 2 in my next
version so that
the move becomes clearer. I will keep your comment in mind for future CL's.

> Please get review from some internal-to-google developers before
> submitting your next version of this series.

Acknowledged.

Best Regards,
Pavan

Re: [PATCH 2/3] usb: typec: ucsi: Import interface for UCSI transport

[Pavan Holla]

On Mon, Mar 25, 2024 at 7:11 PM Prashant Malani <pmalani@chromium.org> wrote:
> Can you squash Patch 1/3 and this Patch (2/3)? It sounds like an
> atomic change that doesn't need two patches.

Acknowledged. Will do it in the next version.

Thanks,
Pavan

Re: [PATCH 3/3] platform/chrome: cros_ec_ucsi: Implement UCSI PDC driver

[kernel test robot]

Hi Pavan,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 4cece764965020c22cff7665b18a012006359095]

url:    https://github.com/intel-lab-lkp/linux/commits/Pavan-Holla/usb-typec-ucsi-Provide-interface-for-UCSI-transport/20240326-074003
base:   4cece764965020c22cff7665b18a012006359095
patch link:    https://lore.kernel.org/r/20240325-public-ucsi-h-v1-3-7c7e888edc0a%40chromium.org
patch subject: [PATCH 3/3] platform/chrome: cros_ec_ucsi: Implement UCSI PDC driver
config: x86_64-randconfig-123-20240328 (https://download.01.org/0day-ci/archive/20240328/202403281639.AVfLPAVm-lkp@intel.com/config)
compiler: gcc-12 (Ubuntu 12.3.0-9ubuntu2) 12.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240328/202403281639.AVfLPAVm-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202403281639.AVfLPAVm-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> drivers/platform/chrome/cros_ec_ucsi.c:119:24: sparse: sparse: symbol 'cros_ucsi_ops' was not declared. Should it be static?

vim +/cros_ucsi_ops +119 drivers/platform/chrome/cros_ec_ucsi.c

   118	
 > 119	struct ucsi_operations cros_ucsi_ops = {
   120		.read = cros_ucsi_read,
   121		.async_write = cros_ucsi_async_write,
   122		.sync_write = cros_ucsi_sync_write,
   123	};
   124	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki