[PATCH v5 0/7] platform/chrome: Type-C switch driver

[PATCH v5 0/7] platform/chrome: Type-C switch driver

[Prashant Malani]

v4 of this series was originally merged to the USB maintainer tree, but
there were dependencies from the chrome-platform tree which caused
conflicts in the merge tree, so the chrome specific parts were
reverted [1].

v5 is a resubmission of the series with the Chrome-only parts (since the
USB framework parts were merged successfully).

[1] https://lore.kernel.org/lkml/YtadE201j+dt5jJx@kroah.com/

Original cover letter (with parts relating to USB patches removed):

This series introduces a retimer class to the USB Type-C framework,
It also introduces a Chrome EC (Embedded Controller) switch driver which
registers the aforementioned retimer switches as well as mode-switches.

v4: https://lore.kernel.org/linux-usb/20220711072333.2064341-1-pmalani@chromium.org/

Changes in v5:
- Removed first 2 patches for retimer class support, since those were
  merged in 5.20.
- Added missing ACPI Kconfig to Patch 2/7.
- Updated patches 3/7 and 4/7 to use new function name cros_ec_cmd().


Prashant Malani (7):
  platform/chrome: Add Type-C mux set command definitions
  platform/chrome: cros_typec_switch: Add switch driver
  platform/chrome: cros_typec_switch: Set EC retimer
  platform/chrome: cros_typec_switch: Add event check
  platform/chrome: cros_typec_switch: Register mode switches
  platform/chrome: cros_ec_typec: Cleanup switch handle return paths
  platform/chrome: cros_ec_typec: Get retimer handle

 MAINTAINERS                                   |   1 +
 drivers/platform/chrome/Kconfig               |  11 +
 drivers/platform/chrome/Makefile              |   1 +
 drivers/platform/chrome/cros_ec_typec.c       |  50 ++-
 drivers/platform/chrome/cros_typec_switch.c   | 332 ++++++++++++++++++
 .../linux/platform_data/cros_ec_commands.h    |  18 +
 6 files changed, 406 insertions(+), 7 deletions(-)
 create mode 100644 drivers/platform/chrome/cros_typec_switch.c

-- 
2.37.1.595.g718a3a8f04-goog

[PATCH v5 1/7] platform/chrome: Add Type-C mux set command definitions

[Prashant Malani]

Copy EC header definitions for the USB Type-C Mux control command from
the EC code base. Also pull in "TBT_UFP_REPLY" definitions, since that
is the prior entry in the enum.

These headers are already present in the EC code base. [1]

[1] https://chromium.googlesource.com/chromiumos/platform/ec/+/b80f85a94a423273c1638ef7b662c56931a138dd/include/ec_commands.h

Signed-off-by: Prashant Malani <pmalani@chromium.org>
---
Changes since v4:
- No changes.

Changes since v3:
- No changes.

Changes since v2:
- No changes.

Changes since v1:
- No changes.

 include/linux/platform_data/cros_ec_commands.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/include/linux/platform_data/cros_ec_commands.h b/include/linux/platform_data/cros_ec_commands.h
index 8b1b795867a1..5744a2d746aa 100644
--- a/include/linux/platform_data/cros_ec_commands.h
+++ b/include/linux/platform_data/cros_ec_commands.h
@@ -5724,8 +5724,21 @@ enum typec_control_command {
 	TYPEC_CONTROL_COMMAND_EXIT_MODES,
 	TYPEC_CONTROL_COMMAND_CLEAR_EVENTS,
 	TYPEC_CONTROL_COMMAND_ENTER_MODE,
+	TYPEC_CONTROL_COMMAND_TBT_UFP_REPLY,
+	TYPEC_CONTROL_COMMAND_USB_MUX_SET,
 };
 
+/* Replies the AP may specify to the TBT EnterMode command as a UFP */
+enum typec_tbt_ufp_reply {
+	TYPEC_TBT_UFP_REPLY_NAK,
+	TYPEC_TBT_UFP_REPLY_ACK,
+};
+
+struct typec_usb_mux_set {
+	uint8_t mux_index;	/* Index of the mux to set in the chain */
+	uint8_t mux_flags;	/* USB_PD_MUX_*-encoded USB mux state to set */
+} __ec_align1;
+
 struct ec_params_typec_control {
 	uint8_t port;
 	uint8_t command;	/* enum typec_control_command */
@@ -5739,6 +5752,8 @@ struct ec_params_typec_control {
 	union {
 		uint32_t clear_events_mask;
 		uint8_t mode_to_enter;      /* enum typec_mode */
+		uint8_t tbt_ufp_reply;      /* enum typec_tbt_ufp_reply */
+		struct typec_usb_mux_set mux_params;
 		uint8_t placeholder[128];
 	};
 } __ec_align1;
@@ -5817,6 +5832,9 @@ enum tcpc_cc_polarity {
 #define PD_STATUS_EVENT_SOP_DISC_DONE		BIT(0)
 #define PD_STATUS_EVENT_SOP_PRIME_DISC_DONE	BIT(1)
 #define PD_STATUS_EVENT_HARD_RESET		BIT(2)
+#define PD_STATUS_EVENT_DISCONNECTED		BIT(3)
+#define PD_STATUS_EVENT_MUX_0_SET_DONE		BIT(4)
+#define PD_STATUS_EVENT_MUX_1_SET_DONE		BIT(5)
 
 struct ec_params_typec_status {
 	uint8_t port;
-- 
2.37.1.595.g718a3a8f04-goog

[PATCH v5 2/7] platform/chrome: cros_typec_switch: Add switch driver

[Prashant Malani]

Introduce a driver to configure USB Type-C mode switches and retimers
which are controlled by the Chrome OS EC (Embedded Controller).
This allows Type-C port drivers, as well as alternate mode drivers to
configure their relevant mode switches and retimers according to the
Type-C state they want to achieve.

ACPI devices with ID GOOG001A will bind to this driver.

Currently, we only register a retimer switch with a stub set function.
Subsequent patches will implement the host command set functionality,
and introduce mode switches.

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

Changes since v4:
- Add ACPI dependency to Kconfig.

Changes since v3:
- No changes.

Changes since v2:
- Fixed missing "static" identifier.
- Removed unnecessary new line for function signature.

Changes since v1:
- No changes.

 MAINTAINERS                                 |   1 +
 drivers/platform/chrome/Kconfig             |  11 ++
 drivers/platform/chrome/Makefile            |   1 +
 drivers/platform/chrome/cros_typec_switch.c | 170 ++++++++++++++++++++
 4 files changed, 183 insertions(+)
 create mode 100644 drivers/platform/chrome/cros_typec_switch.c

diff --git a/MAINTAINERS b/MAINTAINERS
index b7221f4143cb..6fa4da411275 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4884,6 +4884,7 @@ M:	Prashant Malani <pmalani@chromium.org>
 L:	chrome-platform@lists.linux.dev
 S:	Maintained
 F:	drivers/platform/chrome/cros_ec_typec.c
+F:	drivers/platform/chrome/cros_typec_switch.c
 
 CHROMEOS EC USB PD NOTIFY DRIVER
 M:	Prashant Malani <pmalani@chromium.org>
diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
index c45fb376d653..55b68f247f02 100644
--- a/drivers/platform/chrome/Kconfig
+++ b/drivers/platform/chrome/Kconfig
@@ -265,6 +265,17 @@ config CHROMEOS_PRIVACY_SCREEN
 	  this should probably always be built into the kernel to avoid or
 	  minimize drm probe deferral.
 
+config CROS_TYPEC_SWITCH
+	tristate "ChromeOS EC Type-C Switch Control"
+	depends on MFD_CROS_EC_DEV && TYPEC && ACPI
+	default MFD_CROS_EC_DEV
+	help
+	  If you say Y here, you get support for configuring the Chrome OS EC Type C
+	  muxes and retimers.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called cros_typec_switch.
+
 source "drivers/platform/chrome/wilco_ec/Kconfig"
 
 # Kunit test cases
diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
index f7e74a845afc..2950610101f1 100644
--- a/drivers/platform/chrome/Makefile
+++ b/drivers/platform/chrome/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_CHROMEOS_TBMC)		+= chromeos_tbmc.o
 obj-$(CONFIG_CROS_EC)			+= cros_ec.o
 obj-$(CONFIG_CROS_EC_I2C)		+= cros_ec_i2c.o
 obj-$(CONFIG_CROS_EC_ISHTP)		+= cros_ec_ishtp.o
+obj-$(CONFIG_CROS_TYPEC_SWITCH)		+= cros_typec_switch.o
 obj-$(CONFIG_CROS_EC_RPMSG)		+= cros_ec_rpmsg.o
 obj-$(CONFIG_CROS_EC_SPI)		+= cros_ec_spi.o
 cros_ec_lpcs-objs			:= cros_ec_lpc.o cros_ec_lpc_mec.o
diff --git a/drivers/platform/chrome/cros_typec_switch.c b/drivers/platform/chrome/cros_typec_switch.c
new file mode 100644
index 000000000000..0d319e315d57
--- /dev/null
+++ b/drivers/platform/chrome/cros_typec_switch.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2022 Google LLC
+ *
+ * This driver provides the ability to configure Type C muxes and retimers which are controlled by
+ * the Chrome OS EC.
+ */
+
+#include <linux/acpi.h>
+#include <linux/module.h>
+#include <linux/platform_data/cros_ec_commands.h>
+#include <linux/platform_device.h>
+#include <linux/usb/typec_retimer.h>
+
+#define DRV_NAME "cros-typec-switch"
+
+/* Handles and other relevant data required for each port's switches. */
+struct cros_typec_port {
+	int port_num;
+	struct typec_retimer *retimer;
+	struct cros_typec_switch_data *sdata;
+};
+
+/* Driver-specific data. */
+struct cros_typec_switch_data {
+	struct device *dev;
+	struct cros_ec_device *ec;
+	struct cros_typec_port *ports[EC_USB_PD_MAX_PORTS];
+};
+
+static int cros_typec_retimer_set(struct typec_retimer *retimer, struct typec_retimer_state *state)
+{
+	return 0;
+}
+
+static void cros_typec_unregister_switches(struct cros_typec_switch_data *sdata)
+{
+	int i;
+
+	for (i = 0; i < EC_USB_PD_MAX_PORTS; i++) {
+		if (!sdata->ports[i])
+			continue;
+		typec_retimer_unregister(sdata->ports[i]->retimer);
+	}
+}
+
+static int cros_typec_register_retimer(struct cros_typec_port *port, struct fwnode_handle *fwnode)
+{
+	struct typec_retimer_desc retimer_desc = {
+		.fwnode = fwnode,
+		.drvdata = port,
+		.name = fwnode_get_name(fwnode),
+		.set = cros_typec_retimer_set,
+	};
+
+	port->retimer = typec_retimer_register(port->sdata->dev, &retimer_desc);
+	if (IS_ERR(port->retimer))
+		return PTR_ERR(port->retimer);
+
+	return 0;
+}
+
+static int cros_typec_register_switches(struct cros_typec_switch_data *sdata)
+{
+	struct cros_typec_port *port = NULL;
+	struct device *dev = sdata->dev;
+	struct fwnode_handle *fwnode;
+	struct acpi_device *adev;
+	unsigned long long index;
+	int ret = 0;
+	int nports;
+
+	nports = device_get_child_node_count(dev);
+	if (nports == 0) {
+		dev_err(dev, "No switch devices found.\n");
+		return -ENODEV;
+	}
+
+	device_for_each_child_node(dev, fwnode) {
+		port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
+		if (!port) {
+			ret = -ENOMEM;
+			goto err_switch;
+		}
+
+		adev = to_acpi_device_node(fwnode);
+		if (!adev) {
+			dev_err(fwnode->dev, "Couldn't get ACPI device handle\n");
+			ret = -ENODEV;
+			goto err_switch;
+		}
+
+		ret = acpi_evaluate_integer(adev->handle, "_ADR", NULL, &index);
+		if (ACPI_FAILURE(ret)) {
+			dev_err(fwnode->dev, "_ADR wasn't evaluated\n");
+			ret = -ENODATA;
+			goto err_switch;
+		}
+
+		if (index < 0 || index >= EC_USB_PD_MAX_PORTS) {
+			dev_err(fwnode->dev, "Invalid port index number: %llu", index);
+			ret = -EINVAL;
+			goto err_switch;
+		}
+		port->sdata = sdata;
+		port->port_num = index;
+		sdata->ports[index] = port;
+
+		ret = cros_typec_register_retimer(port, fwnode);
+		if (ret) {
+			dev_err(dev, "Retimer switch register failed\n");
+			goto err_switch;
+		}
+
+		dev_dbg(dev, "Retimer switch registered for index %llu\n", index);
+	}
+
+	return 0;
+err_switch:
+	cros_typec_unregister_switches(sdata);
+	return ret;
+}
+
+static int cros_typec_switch_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct cros_typec_switch_data *sdata;
+
+	sdata = devm_kzalloc(dev, sizeof(*sdata), GFP_KERNEL);
+	if (!sdata)
+		return -ENOMEM;
+
+	sdata->dev = dev;
+	sdata->ec = dev_get_drvdata(pdev->dev.parent);
+
+	platform_set_drvdata(pdev, sdata);
+
+	return cros_typec_register_switches(sdata);
+}
+
+static int cros_typec_switch_remove(struct platform_device *pdev)
+{
+	struct cros_typec_switch_data *sdata = platform_get_drvdata(pdev);
+
+	cros_typec_unregister_switches(sdata);
+	return 0;
+}
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id cros_typec_switch_acpi_id[] = {
+	{ "GOOG001A", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, cros_typec_switch_acpi_id);
+#endif
+
+static struct platform_driver cros_typec_switch_driver = {
+	.driver	= {
+		.name = DRV_NAME,
+		.acpi_match_table = ACPI_PTR(cros_typec_switch_acpi_id),
+	},
+	.probe = cros_typec_switch_probe,
+	.remove = cros_typec_switch_remove,
+};
+
+module_platform_driver(cros_typec_switch_driver);
+
+MODULE_AUTHOR("Prashant Malani <pmalani@chromium.org>");
+MODULE_DESCRIPTION("Chrome OS EC Type C Switch control");
+MODULE_LICENSE("GPL");
-- 
2.37.1.595.g718a3a8f04-goog

[PATCH v5 3/7] platform/chrome: cros_typec_switch: Set EC retimer

[Prashant Malani]

Invoke Chrome EC host commands to set EC-controlled retimer switches to
the state the Type-C framework instructs.

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

Changes since v4:
- Update cros_ec_command() to cros_ec_cmd().

Changes since v3:
- No changes.

Changes since v2:
- No changes.

Changes since v1:
- No changes.

 drivers/platform/chrome/cros_typec_switch.c | 56 ++++++++++++++++++++-
 1 file changed, 55 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/chrome/cros_typec_switch.c b/drivers/platform/chrome/cros_typec_switch.c
index 0d319e315d57..befe35655a9a 100644
--- a/drivers/platform/chrome/cros_typec_switch.c
+++ b/drivers/platform/chrome/cros_typec_switch.c
@@ -9,7 +9,10 @@
 #include <linux/acpi.h>
 #include <linux/module.h>
 #include <linux/platform_data/cros_ec_commands.h>
+#include <linux/platform_data/cros_ec_proto.h>
 #include <linux/platform_device.h>
+#include <linux/usb/typec_altmode.h>
+#include <linux/usb/typec_dp.h>
 #include <linux/usb/typec_retimer.h>
 
 #define DRV_NAME "cros-typec-switch"
@@ -28,9 +31,60 @@ struct cros_typec_switch_data {
 	struct cros_typec_port *ports[EC_USB_PD_MAX_PORTS];
 };
 
+static int cros_typec_cmd_mux_set(struct cros_typec_switch_data *sdata, int port_num, u8 index,
+				  u8 state)
+{
+	struct typec_usb_mux_set params = {
+		.mux_index = index,
+		.mux_flags = state,
+	};
+
+	struct ec_params_typec_control req = {
+		.port = port_num,
+		.command = TYPEC_CONTROL_COMMAND_USB_MUX_SET,
+		.mux_params = params,
+	};
+
+	return cros_ec_cmd(sdata->ec, 0, EC_CMD_TYPEC_CONTROL, &req,
+			   sizeof(req), NULL, 0);
+}
+
+static int cros_typec_get_mux_state(unsigned long mode, struct typec_altmode *alt)
+{
+	int ret = -EOPNOTSUPP;
+
+	if (mode == TYPEC_STATE_SAFE)
+		ret = USB_PD_MUX_SAFE_MODE;
+	else if (mode == TYPEC_STATE_USB)
+		ret = USB_PD_MUX_USB_ENABLED;
+	else if (alt && alt->svid == USB_TYPEC_DP_SID)
+		ret = USB_PD_MUX_DP_ENABLED;
+
+	return ret;
+}
+
+/*
+ * The Chrome EC treats both mode-switches and retimers as "muxes" for the purposes of the
+ * host command API. This common function configures and verifies the retimer/mode-switch
+ * according to the provided setting.
+ */
+static int cros_typec_configure_mux(struct cros_typec_switch_data *sdata, int port_num, int index,
+				    unsigned long mode, struct typec_altmode *alt)
+{
+	int ret = cros_typec_get_mux_state(mode, alt);
+
+	if (ret < 0)
+		return ret;
+
+	return cros_typec_cmd_mux_set(sdata, port_num, index, (u8)ret);
+}
+
 static int cros_typec_retimer_set(struct typec_retimer *retimer, struct typec_retimer_state *state)
 {
-	return 0;
+	struct cros_typec_port *port = typec_retimer_get_drvdata(retimer);
+
+	/* Retimers have index 1. */
+	return cros_typec_configure_mux(port->sdata, port->port_num, 1, state->mode, state->alt);
 }
 
 static void cros_typec_unregister_switches(struct cros_typec_switch_data *sdata)
-- 
2.37.1.595.g718a3a8f04-goog

[PATCH v5 4/7] platform/chrome: cros_typec_switch: Add event check

[Prashant Malani]

The Chrome EC updates Type-C status events when mux set requests from
the Application Processor (AP) are completed. Add a check to the
flow of configuring muxes to look for this status done bit, so that
the driver is aware that the mux set completed successfully or not.

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

Changes since v4:
- Update cros_ec_command() to cros_ec_cmd().
- Dropped unnecessary Reported-by tag (since this patch is not a
  bug fix).

Changes since v3:
- No changes.

Changes since v2:
- Fixed missing "static" identifier.

Changes since v1:
- No changes.

 drivers/platform/chrome/cros_typec_switch.c | 72 ++++++++++++++++++++-
 1 file changed, 70 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/chrome/cros_typec_switch.c b/drivers/platform/chrome/cros_typec_switch.c
index befe35655a9a..a9e114391321 100644
--- a/drivers/platform/chrome/cros_typec_switch.c
+++ b/drivers/platform/chrome/cros_typec_switch.c
@@ -7,6 +7,8 @@
  */
 
 #include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/jiffies.h>
 #include <linux/module.h>
 #include <linux/platform_data/cros_ec_commands.h>
 #include <linux/platform_data/cros_ec_proto.h>
@@ -63,6 +65,40 @@ static int cros_typec_get_mux_state(unsigned long mode, struct typec_altmode *al
 	return ret;
 }
 
+static int cros_typec_send_clear_event(struct cros_typec_switch_data *sdata, int port_num,
+				       u32 events_mask)
+{
+	struct ec_params_typec_control req = {
+		.port = port_num,
+		.command = TYPEC_CONTROL_COMMAND_CLEAR_EVENTS,
+		.clear_events_mask = events_mask,
+	};
+
+	return cros_ec_cmd(sdata->ec, 0, EC_CMD_TYPEC_CONTROL, &req,
+			   sizeof(req), NULL, 0);
+}
+
+static bool cros_typec_check_event(struct cros_typec_switch_data *sdata, int port_num, u32 mask)
+{
+	struct ec_response_typec_status resp;
+	struct ec_params_typec_status req = {
+		.port = port_num,
+	};
+	int ret;
+
+	ret = cros_ec_cmd(sdata->ec, 0, EC_CMD_TYPEC_STATUS, &req, sizeof(req),
+			  &resp, sizeof(resp));
+	if (ret < 0) {
+		dev_warn(sdata->dev, "EC_CMD_TYPEC_STATUS failed for port: %d\n", port_num);
+		return false;
+	}
+
+	if (resp.events & mask)
+		return true;
+
+	return false;
+}
+
 /*
  * The Chrome EC treats both mode-switches and retimers as "muxes" for the purposes of the
  * host command API. This common function configures and verifies the retimer/mode-switch
@@ -71,12 +107,44 @@ static int cros_typec_get_mux_state(unsigned long mode, struct typec_altmode *al
 static int cros_typec_configure_mux(struct cros_typec_switch_data *sdata, int port_num, int index,
 				    unsigned long mode, struct typec_altmode *alt)
 {
-	int ret = cros_typec_get_mux_state(mode, alt);
+	unsigned long end;
+	u32 event_mask;
+	u8 mux_state;
+	int ret;
+
+	ret = cros_typec_get_mux_state(mode, alt);
+	if (ret < 0)
+		return ret;
+	mux_state = (u8)ret;
 
+	/* Clear any old mux set done event. */
+	if (index == 0)
+		event_mask = PD_STATUS_EVENT_MUX_0_SET_DONE;
+	else
+		event_mask = PD_STATUS_EVENT_MUX_1_SET_DONE;
+
+	ret = cros_typec_send_clear_event(sdata, port_num, event_mask);
+	if (ret < 0)
+		return ret;
+
+	/* Send the set command. */
+	ret = cros_typec_cmd_mux_set(sdata, port_num, index, mux_state);
 	if (ret < 0)
 		return ret;
 
-	return cros_typec_cmd_mux_set(sdata, port_num, index, (u8)ret);
+	/* Check for the mux set done event. */
+	end = jiffies + msecs_to_jiffies(1000);
+	do {
+		if (cros_typec_check_event(sdata, port_num, event_mask))
+			return 0;
+
+		usleep_range(500, 1000);
+	} while (time_before(jiffies, end));
+
+	dev_err(sdata->dev, "Timed out waiting for mux set done on index: %d, state: %d\n",
+		index, mux_state);
+
+	return -ETIMEDOUT;
 }
 
 static int cros_typec_retimer_set(struct typec_retimer *retimer, struct typec_retimer_state *state)
-- 
2.37.1.595.g718a3a8f04-goog

[PATCH v5 5/7] platform/chrome: cros_typec_switch: Register mode switches

[Prashant Malani]

Register mode switch devices for Type C connectors, when they are
specified by firmware. These control Type C configuration for any USB
Type-C mode switches (sometimes known as "muxes") which are controlled
by the Chrome EC.

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

Changes since v4:
- No changes.

Changes since v3:
- No changes.

Changes since v2:
- Fixed missing "static" identifier.

Changes since v1:
- No changes.

 drivers/platform/chrome/cros_typec_switch.c | 40 +++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/drivers/platform/chrome/cros_typec_switch.c b/drivers/platform/chrome/cros_typec_switch.c
index a9e114391321..9eb37b3b754f 100644
--- a/drivers/platform/chrome/cros_typec_switch.c
+++ b/drivers/platform/chrome/cros_typec_switch.c
@@ -15,6 +15,7 @@
 #include <linux/platform_device.h>
 #include <linux/usb/typec_altmode.h>
 #include <linux/usb/typec_dp.h>
+#include <linux/usb/typec_mux.h>
 #include <linux/usb/typec_retimer.h>
 
 #define DRV_NAME "cros-typec-switch"
@@ -22,6 +23,7 @@
 /* Handles and other relevant data required for each port's switches. */
 struct cros_typec_port {
 	int port_num;
+	struct typec_mux_dev *mode_switch;
 	struct typec_retimer *retimer;
 	struct cros_typec_switch_data *sdata;
 };
@@ -147,6 +149,15 @@ static int cros_typec_configure_mux(struct cros_typec_switch_data *sdata, int po
 	return -ETIMEDOUT;
 }
 
+static int cros_typec_mode_switch_set(struct typec_mux_dev *mode_switch,
+				      struct typec_mux_state *state)
+{
+	struct cros_typec_port *port = typec_mux_get_drvdata(mode_switch);
+
+	/* Mode switches have index 0. */
+	return cros_typec_configure_mux(port->sdata, port->port_num, 0, state->mode, state->alt);
+}
+
 static int cros_typec_retimer_set(struct typec_retimer *retimer, struct typec_retimer_state *state)
 {
 	struct cros_typec_port *port = typec_retimer_get_drvdata(retimer);
@@ -163,9 +174,27 @@ static void cros_typec_unregister_switches(struct cros_typec_switch_data *sdata)
 		if (!sdata->ports[i])
 			continue;
 		typec_retimer_unregister(sdata->ports[i]->retimer);
+		typec_mux_unregister(sdata->ports[i]->mode_switch);
 	}
 }
 
+static int cros_typec_register_mode_switch(struct cros_typec_port *port,
+					   struct fwnode_handle *fwnode)
+{
+	struct typec_mux_desc mode_switch_desc = {
+		.fwnode = fwnode,
+		.drvdata = port,
+		.name = fwnode_get_name(fwnode),
+		.set = cros_typec_mode_switch_set,
+	};
+
+	port->mode_switch = typec_mux_register(port->sdata->dev, &mode_switch_desc);
+	if (IS_ERR(port->mode_switch))
+		return PTR_ERR(port->mode_switch);
+
+	return 0;
+}
+
 static int cros_typec_register_retimer(struct cros_typec_port *port, struct fwnode_handle *fwnode)
 {
 	struct typec_retimer_desc retimer_desc = {
@@ -235,6 +264,17 @@ static int cros_typec_register_switches(struct cros_typec_switch_data *sdata)
 		}
 
 		dev_dbg(dev, "Retimer switch registered for index %llu\n", index);
+
+		if (!fwnode_property_read_bool(fwnode, "mode-switch"))
+			continue;
+
+		ret = cros_typec_register_mode_switch(port, fwnode);
+		if (ret) {
+			dev_err(dev, "Mode switch register failed\n");
+			goto err_switch;
+		}
+
+		dev_dbg(dev, "Mode switch registered for index %llu\n", index);
 	}
 
 	return 0;
-- 
2.37.1.595.g718a3a8f04-goog

[PATCH v5 6/7] platform/chrome: cros_ec_typec: Cleanup switch handle return paths

[Prashant Malani]

Some of the return paths for the cros_typec_get_switch_handles()
aren't necessary. Clean up the return paths to only undo the handle
get's which succeeded.

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

Changes since v4:
- No changes.

Changes since v3:
- No changes.

Changes since v2:
- No changes.

Changes since v1:
- No changes.

 drivers/platform/chrome/cros_ec_typec.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
index de6ee0f926a6..ee54add992db 100644
--- a/drivers/platform/chrome/cros_ec_typec.c
+++ b/drivers/platform/chrome/cros_ec_typec.c
@@ -158,12 +158,10 @@ static int cros_typec_get_switch_handles(struct cros_typec_port *port,
 	return 0;
 
 role_sw_err:
-	usb_role_switch_put(port->role_sw);
-ori_sw_err:
 	typec_switch_put(port->ori_sw);
-mux_err:
+ori_sw_err:
 	typec_mux_put(port->mux);
-
+mux_err:
 	return -ENODEV;
 }
 
-- 
2.37.1.595.g718a3a8f04-goog

[PATCH v5 7/7] platform/chrome: cros_ec_typec: Get retimer handle

[Prashant Malani]

Where available, obtain the handle to retimer switch specified via
firmware, and update the mux configuration callsites to add retimer
support for supported modes.

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

Changes since v4:
- No changes.

Changes since v3:
- No changes.

Changes since v2:
- No changes.

Changes since v1:
- No changes.

 drivers/platform/chrome/cros_ec_typec.c | 44 +++++++++++++++++++++++--
 1 file changed, 41 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
index ee54add992db..a1f804ba9dca 100644
--- a/drivers/platform/chrome/cros_ec_typec.c
+++ b/drivers/platform/chrome/cros_ec_typec.c
@@ -20,6 +20,7 @@
 #include <linux/usb/typec_altmode.h>
 #include <linux/usb/typec_dp.h>
 #include <linux/usb/typec_mux.h>
+#include <linux/usb/typec_retimer.h>
 #include <linux/usb/typec_tbt.h>
 #include <linux/usb/role.h>
 
@@ -55,6 +56,7 @@ struct cros_typec_port {
 	struct usb_pd_identity c_identity;
 	struct typec_switch *ori_sw;
 	struct typec_mux *mux;
+	struct typec_retimer *retimer;
 	struct usb_role_switch *role_sw;
 
 	/* Variables keeping track of switch state. */
@@ -143,6 +145,12 @@ static int cros_typec_get_switch_handles(struct cros_typec_port *port,
 		goto mux_err;
 	}
 
+	port->retimer = fwnode_typec_retimer_get(fwnode);
+	if (IS_ERR(port->retimer)) {
+		dev_dbg(dev, "Retimer handle not found.\n");
+		goto retimer_sw_err;
+	}
+
 	port->ori_sw = fwnode_typec_switch_get(fwnode);
 	if (IS_ERR(port->ori_sw)) {
 		dev_dbg(dev, "Orientation switch handle not found.\n");
@@ -160,6 +168,8 @@ static int cros_typec_get_switch_handles(struct cros_typec_port *port,
 role_sw_err:
 	typec_switch_put(port->ori_sw);
 ori_sw_err:
+	typec_retimer_put(port->retimer);
+retimer_sw_err:
 	typec_mux_put(port->mux);
 mux_err:
 	return -ENODEV;
@@ -204,6 +214,21 @@ static void cros_typec_unregister_altmodes(struct cros_typec_data *typec, int po
 	}
 }
 
+/*
+ * Map the Type-C Mux state to retimer state and call the retimer set function. We need this
+ * because we re-use the Type-C mux state for retimers.
+ */
+static int cros_typec_retimer_set(struct typec_retimer  *retimer, struct typec_mux_state state)
+{
+	struct typec_retimer_state rstate = {
+		.alt = state.alt,
+		.mode = state.mode,
+		.data = state.data,
+	};
+
+	return typec_retimer_set(retimer, &rstate);
+}
+
 static int cros_typec_usb_disconnect_state(struct cros_typec_port *port)
 {
 	port->state.alt = NULL;
@@ -212,6 +237,7 @@ static int cros_typec_usb_disconnect_state(struct cros_typec_port *port)
 
 	usb_role_switch_set_role(port->role_sw, USB_ROLE_NONE);
 	typec_switch_set(port->ori_sw, TYPEC_ORIENTATION_NONE);
+	cros_typec_retimer_set(port->retimer, port->state);
 
 	return typec_mux_set(port->mux, &port->state);
 }
@@ -409,9 +435,14 @@ static int cros_typec_init_ports(struct cros_typec_data *typec)
 
 static int cros_typec_usb_safe_state(struct cros_typec_port *port)
 {
+	int ret;
 	port->state.mode = TYPEC_STATE_SAFE;
 
-	return typec_mux_set(port->mux, &port->state);
+	ret = cros_typec_retimer_set(port->retimer, port->state);
+	if (!ret)
+		ret = typec_mux_set(port->mux, &port->state);
+
+	return ret;
 }
 
 /*
@@ -508,7 +539,11 @@ static int cros_typec_enable_dp(struct cros_typec_data *typec,
 	port->state.data = &dp_data;
 	port->state.mode = TYPEC_MODAL_STATE(ffs(pd_ctrl->dp_mode));
 
-	return typec_mux_set(port->mux, &port->state);
+	ret = cros_typec_retimer_set(port->retimer, port->state);
+	if (!ret)
+		ret = typec_mux_set(port->mux, &port->state);
+
+	return ret;
 }
 
 static int cros_typec_enable_usb4(struct cros_typec_data *typec,
@@ -597,7 +632,10 @@ static int cros_typec_configure_mux(struct cros_typec_data *typec, int port_num,
 	} else if (port->mux_flags & USB_PD_MUX_USB_ENABLED) {
 		port->state.alt = NULL;
 		port->state.mode = TYPEC_STATE_USB;
-		ret = typec_mux_set(port->mux, &port->state);
+
+		ret = cros_typec_retimer_set(port->retimer, port->state);
+		if (!ret)
+			ret = typec_mux_set(port->mux, &port->state);
 	} else {
 		dev_dbg(typec->dev,
 			"Unrecognized mode requested, mux flags: %x\n",
-- 
2.37.1.595.g718a3a8f04-goog

Re: [PATCH v5 1/7] platform/chrome: Add Type-C mux set command definitions

[Tzung-Bi Shih]

On Mon, Aug 15, 2022 at 06:34:17AM +0000, Prashant Malani wrote:
> Copy EC header definitions for the USB Type-C Mux control command from
> the EC code base. Also pull in "TBT_UFP_REPLY" definitions, since that
> is the prior entry in the enum.
> 
> These headers are already present in the EC code base. [1]
> 
> [1] https://chromium.googlesource.com/chromiumos/platform/ec/+/b80f85a94a423273c1638ef7b662c56931a138dd/include/ec_commands.h
> 
> Signed-off-by: Prashant Malani <pmalani@chromium.org>

Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>

Re: [PATCH v5 2/7] platform/chrome: cros_typec_switch: Add switch driver

[Tzung-Bi Shih]

On Mon, Aug 15, 2022 at 06:34:19AM +0000, Prashant Malani wrote:
> Introduce a driver to configure USB Type-C mode switches and retimers
> which are controlled by the Chrome OS EC (Embedded Controller).
> This allows Type-C port drivers, as well as alternate mode drivers to
> configure their relevant mode switches and retimers according to the
> Type-C state they want to achieve.

s/Chrome OS/ChromeOS/.

> diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
[...]
> +config CROS_TYPEC_SWITCH
> +	tristate "ChromeOS EC Type-C Switch Control"
> +	depends on MFD_CROS_EC_DEV && TYPEC && ACPI
> +	default MFD_CROS_EC_DEV
> +	help
> +	  If you say Y here, you get support for configuring the Chrome OS EC Type C
> +	  muxes and retimers.

s/Chrome OS/ChromeOS/.

Up to you, s/Type C/Type-C/g.

> diff --git a/drivers/platform/chrome/cros_typec_switch.c b/drivers/platform/chrome/cros_typec_switch.c
> new file mode 100644
> index 000000000000..0d319e315d57
> --- /dev/null
> +++ b/drivers/platform/chrome/cros_typec_switch.c
> @@ -0,0 +1,170 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright 2022 Google LLC
> + *
> + * This driver provides the ability to configure Type C muxes and retimers which are controlled by
> + * the Chrome OS EC.
> + */

s/Chrome OS/ChromeOS/.

> +static int cros_typec_register_switches(struct cros_typec_switch_data *sdata)
> +{
> +	struct cros_typec_port *port = NULL;
> +	struct device *dev = sdata->dev;
> +	struct fwnode_handle *fwnode;
> +	struct acpi_device *adev;
> +	unsigned long long index;
> +	int ret = 0;

`port` and `ret` don't need to be initialized.

> +MODULE_DESCRIPTION("Chrome OS EC Type C Switch control");

s/Chrome OS/ChromeOS/.

Re: [PATCH v5 3/7] platform/chrome: cros_typec_switch: Set EC retimer

[Tzung-Bi Shih]

On Mon, Aug 15, 2022 at 06:34:21AM +0000, Prashant Malani wrote:
> +static int cros_typec_cmd_mux_set(struct cros_typec_switch_data *sdata, int port_num, u8 index,
> +				  u8 state)
> +{
> +	struct typec_usb_mux_set params = {
> +		.mux_index = index,
> +		.mux_flags = state,
> +	};
> +
> +	struct ec_params_typec_control req = {
> +		.port = port_num,
> +		.command = TYPEC_CONTROL_COMMAND_USB_MUX_SET,
> +		.mux_params = params,
> +	};

Would it be better to avoid the memory copy by making `params` inline?

E.g.:
struct ec_params_typec_control req = {
    ...
    .mux_params = {
        ...
    },
    ...

> +/*
> + * The Chrome EC treats both mode-switches and retimers as "muxes" for the purposes of the

To be consistent to the series, I guess you would like to use ChromeOS
instead of Chrome?

Re: [PATCH v5 4/7] platform/chrome: cros_typec_switch: Add event check

[Tzung-Bi Shih]

On Mon, Aug 15, 2022 at 06:34:24AM +0000, Prashant Malani wrote:
> The Chrome EC updates Type-C status events when mux set requests from

To be consistent to the series, I guess you would like to use ChromeOS
instead of Chrome?

> +static int cros_typec_send_clear_event(struct cros_typec_switch_data *sdata, int port_num,
> +				       u32 events_mask)
> +{
[...]
> +	return cros_ec_cmd(sdata->ec, 0, EC_CMD_TYPEC_CONTROL, &req,
> +			   sizeof(req), NULL, 0);

The line can join to the previous line without exceeding col-100.

Re: [PATCH v5 5/7] platform/chrome: cros_typec_switch: Register mode switches

[Tzung-Bi Shih]

On Mon, Aug 15, 2022 at 06:34:26AM +0000, Prashant Malani wrote:
> Register mode switch devices for Type C connectors, when they are
> specified by firmware. These control Type C configuration for any USB
> Type-C mode switches (sometimes known as "muxes") which are controlled
> by the Chrome EC.

To be consistent to the commit message, s/Type C/Type-C/g.

To be consistent to the series, I guess you would like to use ChromeOS
instead of Chrome?

> @@ -235,6 +264,17 @@ static int cros_typec_register_switches(struct cros_typec_switch_data *sdata)
>  		}
>  
>  		dev_dbg(dev, "Retimer switch registered for index %llu\n", index);
> +
> +		if (!fwnode_property_read_bool(fwnode, "mode-switch"))
> +			continue;

Would it be better to use device_property_present()?

Re: [PATCH v5 6/7] platform/chrome: cros_ec_typec: Cleanup switch handle return paths

[Tzung-Bi Shih]

On Mon, Aug 15, 2022 at 06:34:28AM +0000, Prashant Malani wrote:
> Some of the return paths for the cros_typec_get_switch_handles()
> aren't necessary. Clean up the return paths to only undo the handle
> get's which succeeded.
> 
> Signed-off-by: Prashant Malani <pmalani@chromium.org>

Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>

Re: [PATCH v5 7/7] platform/chrome: cros_ec_typec: Get retimer handle

[Tzung-Bi Shih]

On Mon, Aug 15, 2022 at 06:34:30AM +0000, Prashant Malani wrote:
> Where available, obtain the handle to retimer switch specified via
> firmware, and update the mux configuration callsites to add retimer
> support for supported modes.
> 
> Signed-off-by: Prashant Malani <pmalani@chromium.org>

With a nit,
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>

> +static int cros_typec_retimer_set(struct typec_retimer  *retimer, struct typec_mux_state state)

nit: double spaces.

Re: [PATCH v5 2/7] platform/chrome: cros_typec_switch: Add switch driver

[Prashant Malani]

Hi Tzung-Bi,

Thanks for reviewing the patch series.

On Mon, Aug 15, 2022 at 10:11 PM Tzung-Bi Shih <tzungbi@kernel.org> wrote:
>
> On Mon, Aug 15, 2022 at 06:34:19AM +0000, Prashant Malani wrote:
> > Introduce a driver to configure USB Type-C mode switches and retimers
> > which are controlled by the Chrome OS EC (Embedded Controller).
> > This allows Type-C port drivers, as well as alternate mode drivers to
> > configure their relevant mode switches and retimers according to the
> > Type-C state they want to achieve.
>
> s/Chrome OS/ChromeOS/.

Fixed in v6.

>
> > diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
> [...]
> > +config CROS_TYPEC_SWITCH
> > +     tristate "ChromeOS EC Type-C Switch Control"
> > +     depends on MFD_CROS_EC_DEV && TYPEC && ACPI
> > +     default MFD_CROS_EC_DEV
> > +     help
> > +       If you say Y here, you get support for configuring the Chrome OS EC Type C
> > +       muxes and retimers.
>
> s/Chrome OS/ChromeOS/.
>
> Up to you, s/Type C/Type-C/g.

Fixed in v6.

>
> > diff --git a/drivers/platform/chrome/cros_typec_switch.c b/drivers/platform/chrome/cros_typec_switch.c
> > new file mode 100644
> > index 000000000000..0d319e315d57
> > --- /dev/null
> > +++ b/drivers/platform/chrome/cros_typec_switch.c
> > @@ -0,0 +1,170 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Copyright 2022 Google LLC
> > + *
> > + * This driver provides the ability to configure Type C muxes and retimers which are controlled by
> > + * the Chrome OS EC.
> > + */
>
> s/Chrome OS/ChromeOS/.
Fixed in v6.

>
> > +static int cros_typec_register_switches(struct cros_typec_switch_data *sdata)
> > +{
> > +     struct cros_typec_port *port = NULL;
> > +     struct device *dev = sdata->dev;
> > +     struct fwnode_handle *fwnode;
> > +     struct acpi_device *adev;
> > +     unsigned long long index;
> > +     int ret = 0;
>
> `port` and `ret` don't need to be initialized.
Fixed in v6.

>
> > +MODULE_DESCRIPTION("Chrome OS EC Type C Switch control");
>
> s/Chrome OS/ChromeOS/.

Fixed in v6.

Re: [PATCH v5 3/7] platform/chrome: cros_typec_switch: Set EC retimer

[Prashant Malani]

On Mon, Aug 15, 2022 at 10:11 PM Tzung-Bi Shih <tzungbi@kernel.org> wrote:
>
> On Mon, Aug 15, 2022 at 06:34:21AM +0000, Prashant Malani wrote:
> > +static int cros_typec_cmd_mux_set(struct cros_typec_switch_data *sdata, int port_num, u8 index,
> > +                               u8 state)
> > +{
> > +     struct typec_usb_mux_set params = {
> > +             .mux_index = index,
> > +             .mux_flags = state,
> > +     };
> > +
> > +     struct ec_params_typec_control req = {
> > +             .port = port_num,
> > +             .command = TYPEC_CONTROL_COMMAND_USB_MUX_SET,
> > +             .mux_params = params,
> > +     };
>
> Would it be better to avoid the memory copy by making `params` inline?
>
> E.g.:
> struct ec_params_typec_control req = {
>     ...
>     .mux_params = {
>         ...
>     },
>     ...

Done.

>
> > +/*
> > + * The Chrome EC treats both mode-switches and retimers as "muxes" for the purposes of the
>
> To be consistent to the series, I guess you would like to use ChromeOS
> instead of Chrome?
Fixed in v6.

>

Re: [PATCH v5 4/7] platform/chrome: cros_typec_switch: Add event check

[Prashant Malani]

On Mon, Aug 15, 2022 at 10:11 PM Tzung-Bi Shih <tzungbi@kernel.org> wrote:
>
> On Mon, Aug 15, 2022 at 06:34:24AM +0000, Prashant Malani wrote:
> > The Chrome EC updates Type-C status events when mux set requests from
>
> To be consistent to the series, I guess you would like to use ChromeOS
> instead of Chrome?

Fixed in v6.

>
> > +static int cros_typec_send_clear_event(struct cros_typec_switch_data *sdata, int port_num,
> > +                                    u32 events_mask)
> > +{
> [...]
> > +     return cros_ec_cmd(sdata->ec, 0, EC_CMD_TYPEC_CONTROL, &req,
> > +                        sizeof(req), NULL, 0);
>
> The line can join to the previous line without exceeding col-100.
Fixed in v6.

Re: [PATCH v5 5/7] platform/chrome: cros_typec_switch: Register mode switches

[Prashant Malani]

On Mon, Aug 15, 2022 at 10:12 PM Tzung-Bi Shih <tzungbi@kernel.org> wrote:
>
> On Mon, Aug 15, 2022 at 06:34:26AM +0000, Prashant Malani wrote:
> > Register mode switch devices for Type C connectors, when they are
> > specified by firmware. These control Type C configuration for any USB
> > Type-C mode switches (sometimes known as "muxes") which are controlled
> > by the Chrome EC.
>
> To be consistent to the commit message, s/Type C/Type-C/g.
>
> To be consistent to the series, I guess you would like to use ChromeOS
> instead of Chrome?

Done.

>
> > @@ -235,6 +264,17 @@ static int cros_typec_register_switches(struct cros_typec_switch_data *sdata)
> >               }
> >
> >               dev_dbg(dev, "Retimer switch registered for index %llu\n", index);
> > +
> > +             if (!fwnode_property_read_bool(fwnode, "mode-switch"))
> > +                     continue;
>
> Would it be better to use device_property_present()?

Fixed in v6.