[PATCH v2 5/7] platform/chrome: cros_ec_typec: Displayport support

Abhishek Pandit-Subedi
2024-10-30T21:29:13Z

Add support for entering and exiting displayport alt-mode on systems
using AP driven alt-mode.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

Changes in v2:
- Refactored displayport into cros_typec_altmode.c to extract common
implementation between altmodes

MAINTAINERS | 3 +
drivers/platform/chrome/Makefile | 3 +-
drivers/platform/chrome/cros_ec_typec.c | 13 +-
drivers/platform/chrome/cros_ec_typec.h | 1 +
drivers/platform/chrome/cros_typec_altmode.c | 277 +++++++++++++++++++
drivers/platform/chrome/cros_typec_altmode.h | 34 +++
6 files changed, 329 insertions(+), 2 deletions(-)
create mode 100644 drivers/platform/chrome/cros_typec_altmode.c
create mode 100644 drivers/platform/chrome/cros_typec_altmode.h

diff --git a/MAINTAINERS b/MAINTAINERS
index e9659a5a7fb3..de99bcbda7d4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5369,9 +5369,12 @@ F: include/linux/platform_data/cros_usbpd_notify.h

CHROMEOS EC USB TYPE-C DRIVER
M: Prashant Malani <pmalani@chromium.org>
+M: Benson Leung <bleung@chromium.org>
+M: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
L: chrome-platform@lists.linux.dev
S: Maintained
F: drivers/platform/chrome/cros_ec_typec.*
+F: drivers/platform/chrome/cros_typec_altmode.*
F: drivers/platform/chrome/cros_typec_switch.c
F: drivers/platform/chrome/cros_typec_vdm.*

diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
index 2dcc6ccc2302..8b007404c024 100644
--- a/drivers/platform/chrome/Makefile
+++ b/drivers/platform/chrome/Makefile
@@ -17,8 +17,9 @@ obj-$(CONFIG_CROS_EC_RPMSG) += cros_ec_rpmsg.o
obj-$(CONFIG_CROS_EC_SPI) += cros_ec_spi.o
obj-$(CONFIG_CROS_EC_UART) += cros_ec_uart.o
cros_ec_lpcs-objs := cros_ec_lpc.o cros_ec_lpc_mec.o
-cros-ec-typec-objs := cros_ec_typec.o cros_typec_vdm.o
+cros-ec-typec-objs := cros_ec_typec.o cros_typec_vdm.o cros_typec_altmode.o
obj-$(CONFIG_CROS_EC_TYPEC) += cros-ec-typec.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_typec.c b/drivers/platform/chrome/cros_ec_typec.c
index 0c8db11bd8a4..7997e7136c4c 100644
--- a/drivers/platform/chrome/cros_ec_typec.c
+++ b/drivers/platform/chrome/cros_ec_typec.c
@@ -18,6 +18,7 @@

#include "cros_ec_typec.h"
#include "cros_typec_vdm.h"
+#include "cros_typec_altmode.h"

#define DRV_NAME "cros-ec-typec"

@@ -293,12 +294,16 @@ static int cros_typec_register_port_altmodes(struct cros_typec_data *typec,
desc.svid = USB_TYPEC_DP_SID;
desc.mode = USB_TYPEC_DP_MODE;
desc.vdo = DP_PORT_VDO;
- amode = typec_port_register_altmode(port->port, &desc);
+ amode = cros_typec_register_displayport(port, &desc,
+ typec->ap_driven_altmode);
if (IS_ERR(amode))
return PTR_ERR(amode);
port->port_altmode[CROS_EC_ALTMODE_DP] = amode;
+
+#if !IS_ENABLED(CONFIG_TYPEC_DP_ALTMODE)
typec_altmode_set_drvdata(amode, port);
amode->ops = &port_amode_ops;
+#endif

/*
* Register TBT compatibility alt mode. The EC will not enter the mode
@@ -575,6 +580,10 @@ static int cros_typec_enable_dp(struct cros_typec_data *typec,
if (!ret)
ret = typec_mux_set(port->mux, &port->state);

+ if (!ret)
+ cros_typec_displayport_status_update(port->state.alt,
+ port->state.data);
+
return ret;
}

@@ -1254,6 +1263,8 @@ static int cros_typec_probe(struct platform_device *pdev)

typec->typec_cmd_supported = cros_ec_check_features(ec_dev, EC_FEATURE_TYPEC_CMD);
typec->needs_mux_ack = cros_ec_check_features(ec_dev, EC_FEATURE_TYPEC_MUX_REQUIRE_AP_ACK);
+ typec->ap_driven_altmode = cros_ec_check_features(
+ ec_dev, EC_FEATURE_TYPEC_REQUIRE_AP_MODE_ENTRY);

ret = cros_ec_cmd(typec->ec, 0, EC_CMD_USB_PD_PORTS, NULL, 0,
&resp, sizeof(resp));
diff --git a/drivers/platform/chrome/cros_ec_typec.h b/drivers/platform/chrome/cros_ec_typec.h
index deda180a646f..9fd5342bb0ad 100644
--- a/drivers/platform/chrome/cros_ec_typec.h
+++ b/drivers/platform/chrome/cros_ec_typec.h
@@ -39,6 +39,7 @@ struct cros_typec_data {
struct work_struct port_work;
bool typec_cmd_supported;
bool needs_mux_ack;
+ bool ap_driven_altmode;
};

/* Per port data. */
diff --git a/drivers/platform/chrome/cros_typec_altmode.c b/drivers/platform/chrome/cros_typec_altmode.c
new file mode 100644
index 000000000000..af2f077674f1
--- /dev/null
+++ b/drivers/platform/chrome/cros_typec_altmode.c
@@ -0,0 +1,277 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Alt-mode implementation on ChromeOS EC.
+ *
+ * Copyright 2024 Google LLC
+ * Author: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
+ */
+#include "cros_ec_typec.h"
+
+#include <linux/usb/typec_dp.h>
+#include <linux/usb/pd_vdo.h>
+
+#include "cros_typec_altmode.h"
+
+struct cros_typec_dp_data {
+ struct typec_displayport_data data;
+
+ bool configured;
+ bool pending_status_update;
+};
+
+struct cros_typec_altmode_data {
+ struct work_struct work;
+ struct cros_typec_port *port;
+ struct typec_altmode *alt;
+ bool ap_mode_entry;
+
+ u32 header;
+ u32 *vdo_data;
+ u8 vdo_size;
+
+ u16 sid;
+ u8 mode;
+
+ union am_specific {
+ struct cros_typec_dp_data dp;
+ } am_data;
+};
+
+static void cros_typec_altmode_work(struct work_struct *work)
+{
+ struct cros_typec_altmode_data *data =
+ container_of(work, struct cros_typec_altmode_data, work);
+
+ if (typec_altmode_vdm(data->alt, data->header, data->vdo_data,
+ data->vdo_size))
+ dev_err(&data->alt->dev, "VDM 0x%x failed", data->header);
+
+ data->header = 0;
+ data->vdo_data = NULL;
+ data->vdo_size = 0;
+}
+
+static int cros_typec_altmode_enter(struct typec_altmode *alt, u32 *vdo)
+{
+ struct cros_typec_altmode_data *data = typec_altmode_get_drvdata(alt);
+ struct ec_params_typec_control req = {
+ .port = data->port->port_num,
+ .command = TYPEC_CONTROL_COMMAND_ENTER_MODE,
+ };
+ int svdm_version;
+ int ret;
+
+ if (!data->ap_mode_entry) {
+ const struct typec_altmode *partner =
+ typec_altmode_get_partner(alt);
+ dev_warn(&partner->dev,
+ "EC does not support ap driven mode entry\n");
+ return -EOPNOTSUPP;
+ }
+
+ if (data->sid == USB_TYPEC_DP_SID)
+ req.mode_to_enter = CROS_EC_ALTMODE_DP;
+ else
+ return -EOPNOTSUPP;
+
+ ret = cros_ec_cmd(data->port->typec_data->ec, 0, EC_CMD_TYPEC_CONTROL,
+ &req, sizeof(req), NULL, 0);
+ if (ret < 0)
+ return ret;
+
+ svdm_version = typec_altmode_get_svdm_version(alt);
+ if (svdm_version < 0)
+ return svdm_version;
+
+ data->header = VDO(data->sid, 1, svdm_version, CMD_ENTER_MODE);
+ data->header |= VDO_OPOS(data->mode);
+ data->header |= VDO_CMDT(CMDT_RSP_ACK);
+
+ data->vdo_data = NULL;
+ data->vdo_size = 1;
+
+ schedule_work(&data->work);
+
+ return ret;
+}
+
+static int cros_typec_altmode_exit(struct typec_altmode *alt)
+{
+ struct cros_typec_altmode_data *data = typec_altmode_get_drvdata(alt);
+ struct ec_params_typec_control req = {
+ .port = data->port->port_num,
+ .command = TYPEC_CONTROL_COMMAND_EXIT_MODES,
+ };
+ int svdm_version;
+ int ret;
+
+ if (!data->ap_mode_entry) {
+ const struct typec_altmode *partner =
+ typec_altmode_get_partner(alt);
+ dev_warn(&partner->dev,
+ "EC does not support ap driven mode entry\n");
+ return -EOPNOTSUPP;
+ }
+
+ ret = cros_ec_cmd(data->port->typec_data->ec, 0, EC_CMD_TYPEC_CONTROL,
+ &req, sizeof(req), NULL, 0);
+
+ if (ret < 0)
+ return ret;
+
+ svdm_version = typec_altmode_get_svdm_version(alt);
+ if (svdm_version < 0)
+ return svdm_version;
+
+ data->header = VDO(data->sid, 1, svdm_version, CMD_EXIT_MODE);
+ data->header |= VDO_OPOS(data->mode);
+ data->header |= VDO_CMDT(CMDT_RSP_ACK);
+
+ data->vdo_data = NULL;
+ data->vdo_size = 1;
+
+ schedule_work(&data->work);
+
+ return ret;
+}
+
+static int cros_typec_displayport_vdm(struct typec_altmode *alt, u32 header,
+ const u32 *data, int count)
+{
+ struct cros_typec_altmode_data *adata = typec_altmode_get_drvdata(alt);
+
+ int cmd_type = PD_VDO_CMDT(header);
+ int cmd = PD_VDO_CMD(header);
+ int svdm_version;
+
+ if (!adata->ap_mode_entry) {
+ const struct typec_altmode *partner =
+ typec_altmode_get_partner(alt);
+ dev_warn(&partner->dev,
+ "EC does not support ap driven mode entry\n");
+ return -EOPNOTSUPP;
+ }
+
+ svdm_version = typec_altmode_get_svdm_version(alt);
+ if (svdm_version < 0)
+ return svdm_version;
+
+ switch (cmd_type) {
+ case CMDT_INIT:
+ if (PD_VDO_SVDM_VER(header) < svdm_version) {
+ typec_partner_set_svdm_version(adata->port->partner,
+ PD_VDO_SVDM_VER(header));
+ svdm_version = PD_VDO_SVDM_VER(header);
+ }
+
+ adata->header = VDO(adata->sid, 1, svdm_version, cmd);
+ adata->header |= VDO_OPOS(adata->mode);
+
+ /*
+ * DP_CMD_CONFIGURE: We can't actually do anything with the
+ * provided VDO yet so just send back an ACK.
+ *
+ * DP_CMD_STATUS_UPDATE: We wait for Mux changes to send
+ * DPStatus Acks.
+ */
+ switch (cmd) {
+ case DP_CMD_CONFIGURE:
+ adata->am_data.dp.data.conf = *data;
+ adata->header |= VDO_CMDT(CMDT_RSP_ACK);
+ adata->am_data.dp.configured = true;
+ schedule_work(&adata->work);
+ break;
+ case DP_CMD_STATUS_UPDATE:
+ adata->am_data.dp.pending_status_update = true;
+ break;
+ default:
+ adata->header |= VDO_CMDT(CMDT_RSP_ACK);
+ schedule_work(&adata->work);
+ break;
+ }
+
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static int cros_typec_altmode_vdm(struct typec_altmode *alt, u32 header,
+ const u32 *data, int count)
+{
+ struct cros_typec_altmode_data *adata = typec_altmode_get_drvdata(alt);
+
+ if (adata->sid == USB_TYPEC_DP_SID)
+ return cros_typec_displayport_vdm(alt, header, data, count);
+
+ return -EINVAL;
+}
+
+static const struct typec_altmode_ops cros_typec_altmode_ops = {
+ .enter = cros_typec_altmode_enter,
+ .exit = cros_typec_altmode_exit,
+ .vdm = cros_typec_altmode_vdm,
+};
+
+#if IS_ENABLED(CONFIG_TYPEC_DP_ALTMODE)
+int cros_typec_displayport_status_update(struct typec_altmode *altmode,
+ struct typec_displayport_data *data)
+{
+ struct cros_typec_altmode_data *adata =
+ typec_altmode_get_drvdata(altmode);
+
+ if (!adata->am_data.dp.pending_status_update) {
+ dev_dbg(&altmode->dev,
+ "Got DPStatus without a pending request");
+ return 0;
+ }
+
+ if (adata->am_data.dp.configured && adata->am_data.dp.data.conf != data->conf)
+ dev_dbg(&altmode->dev,
+ "DP Conf doesn't match. Requested 0x%04x, Actual 0x%04x",
+ adata->am_data.dp.data.conf, data->conf);
+
+ adata->am_data.dp.data = *data;
+ adata->am_data.dp.pending_status_update = false;
+ adata->header |= VDO_CMDT(CMDT_RSP_ACK);
+ adata->vdo_data = &adata->am_data.dp.data.status;
+ adata->vdo_size = 2;
+
+ schedule_work(&adata->work);
+ return 0;
+}
+
+struct typec_altmode *
+cros_typec_register_displayport(struct cros_typec_port *port,
+ struct typec_altmode_desc *desc,
+ bool ap_mode_entry)
+{
+ struct typec_altmode *alt;
+ struct cros_typec_altmode_data *data;
+
+ alt = typec_port_register_altmode(port->port, desc);
+ if (IS_ERR(alt))
+ return alt;
+
+ data = devm_kzalloc(&alt->dev, sizeof(*data), GFP_KERNEL);
+ if (!data) {
+ typec_unregister_altmode(alt);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ INIT_WORK(&data->work, cros_typec_altmode_work);
+ data->alt = alt;
+ data->port = port;
+ data->ap_mode_entry = ap_mode_entry;
+ data->sid = USB_TYPEC_DP_SID;
+ data->mode = USB_TYPEC_DP_MODE;
+
+ data->am_data.dp.configured = false;
+ typec_altmode_set_ops(alt, &cros_typec_altmode_ops);
+ typec_altmode_set_drvdata(alt, data);
+
+ return alt;
+}
+#endif
diff --git a/drivers/platform/chrome/cros_typec_altmode.h b/drivers/platform/chrome/cros_typec_altmode.h
new file mode 100644
index 000000000000..c6f8fb02c99c
--- /dev/null
+++ b/drivers/platform/chrome/cros_typec_altmode.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __CROS_TYPEC_ALTMODE_H__
+#define __CROS_TYPEC_ALTMODE_H__
+
+struct cros_typec_port;
+struct typec_altmode;
+struct typec_altmode_desc;
+struct typec_displayport_data;
+
+#if IS_ENABLED(CONFIG_TYPEC_DP_ALTMODE)
+struct typec_altmode *
+cros_typec_register_displayport(struct cros_typec_port *port,
+ struct typec_altmode_desc *desc,
+ bool ap_mode_entry);
+
+int cros_typec_displayport_status_update(struct typec_altmode *altmode,
+ struct typec_displayport_data *data);
+#else
+static inline struct typec_altmode *
+cros_typec_register_displayport(struct cros_typec_port *port,
+ struct typec_altmode_desc *desc,
+ bool ap_mode_entry)
+{
+ return typec_port_register_altmode(port->port, desc);
+}
+
+static inline int cros_typec_displayport_status_update(struct typec_altmode *altmode,
+ struct typec_displayport_data *data)
+{
+ return 0;
+}
+#endif
+#endif /* __CROS_TYPEC_ALTMODE_H__ */
--
2.47.0.163.g1226f6d8fa-goog