From: Benson Leung <ble...@chromium.org>

This is the driver for the USB Type C cable detection mechanism
built into the ChromeOS Embedded Controller on systems that
have USB Type-C ports.

At present, this allows for the presence of display out, but in
future, it may also be used to notify host and device type cables
and the presence of power.

Signed-off-by: Benson Leung <ble...@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balle...@collabora.com>
---
Changes since v1:
 Requested by Chanwoo Choi
 - Rename files changing _ for -
 - Remove the unneeded blank line on bottom of header.
 - Remove kobject.h and cros_ec_commands.h includes.
 - Remove the debug message as is not necessary.
 - Use the tab for indentation instead of space for if sentence.
 - Define each variable on different lines when the variables should be
   initialized.
 - Remove EXTCON_USB and EXTCON_USB_HOST as are not really used for now.
 - Add one blank line to split out between state and property setting.
 - Add the author information (header and module)

 Enric Balletbo
 - As Rob suggested to rename the compatible name to something indicating that
   is USB Type C related I also renamed the file names, extcon-cros-ec ->
   extcon-usbc-cros-ec, I think it's more clear.

 drivers/extcon/Kconfig               |   7 +
 drivers/extcon/Makefile              |   1 +
 drivers/extcon/extcon-usbc-cros-ec.c | 415 +++++++++++++++++++++++++++++++++++
 include/linux/mfd/cros_ec_commands.h |  75 +++++++
 4 files changed, 498 insertions(+)
 create mode 100644 drivers/extcon/extcon-usbc-cros-ec.c

diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
index 96bbae5..9e67e68 100644
--- a/drivers/extcon/Kconfig
+++ b/drivers/extcon/Kconfig
@@ -142,4 +142,11 @@ config EXTCON_USB_GPIO
          Say Y here to enable GPIO based USB cable detection extcon support.
          Used typically if GPIO is used for USB ID pin detection.
 
+config EXTCON_USBC_CROS_EC
+       tristate "ChromeOS Embedded Controller EXTCON support"
+       depends on MFD_CROS_EC
+       help
+         Say Y here to enable USB Type C cable detection extcon support when
+         using Chrome OS EC based USB Type-C ports.
+
 endif
diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
index 237ac3f..e4422949 100644
--- a/drivers/extcon/Makefile
+++ b/drivers/extcon/Makefile
@@ -19,3 +19,4 @@ obj-$(CONFIG_EXTCON_QCOM_SPMI_MISC) += extcon-qcom-spmi-misc.o
 obj-$(CONFIG_EXTCON_RT8973A)   += extcon-rt8973a.o
 obj-$(CONFIG_EXTCON_SM5502)    += extcon-sm5502.o
 obj-$(CONFIG_EXTCON_USB_GPIO)  += extcon-usb-gpio.o
+obj-$(CONFIG_EXTCON_USBC_CROS_EC) += extcon-usbc-cros-ec.o
diff --git a/drivers/extcon/extcon-usbc-cros-ec.c 
b/drivers/extcon/extcon-usbc-cros-ec.c
new file mode 100644
index 0000000..e759ed4
--- /dev/null
+++ b/drivers/extcon/extcon-usbc-cros-ec.c
@@ -0,0 +1,415 @@
+/**
+ * drivers/extcon/extcon-usbc-cros-ec - ChromeOS Embedded Controller extcon
+ *
+ * Copyright (C) 2017 Google, Inc
+ * Author: Benson Leung <ble...@chromium.org>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/extcon.h>
+#include <linux/kernel.h>
+#include <linux/mfd/cros_ec.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+
+struct cros_ec_extcon_info {
+       struct device *dev;
+       struct extcon_dev *edev;
+
+       int port_id;
+
+       struct cros_ec_device *ec;
+
+       struct notifier_block notifier;
+
+       bool dp; /* DisplayPort enabled */
+       bool mux; /* SuperSpeed (usb3) enabled */
+       unsigned int power_type;
+};
+
+static const unsigned int usb_type_c_cable[] = {
+       EXTCON_DISP_DP,
+       EXTCON_NONE,
+};
+
+/**
+ * cros_ec_pd_command() - Send a command to the EC.
+ * @info: pointer to struct cros_ec_extcon_info
+ * @command: EC command
+ * @version: EC command version
+ * @outdata: EC command output data
+ * @outsize: Size of outdata
+ * @indata: EC command input data
+ * @insize: Size of indata
+ *
+ * Return: 0 on success, <0 on failure.
+ */
+static int cros_ec_pd_command(struct cros_ec_extcon_info *info,
+                             unsigned int command,
+                             unsigned int version,
+                             void *outdata,
+                             unsigned int outsize,
+                             void *indata,
+                             unsigned int insize)
+{
+       struct cros_ec_command *msg;
+       int ret;
+
+       msg = kzalloc(sizeof(*msg) + max(outsize, insize), GFP_KERNEL);
+
+       msg->version = version;
+       msg->command = command;
+       msg->outsize = outsize;
+       msg->insize = insize;
+
+       if (outsize)
+               memcpy(msg->data, outdata, outsize);
+
+       ret = cros_ec_cmd_xfer_status(info->ec, msg);
+       if (ret >= 0 && insize)
+               memcpy(indata, msg->data, insize);
+
+       kfree(msg);
+       return ret;
+}
+
+/**
+ * cros_ec_usb_get_power_type() - Get power type info about PD device attached
+ * to given port.
+ * @info: pointer to struct cros_ec_extcon_info
+ *
+ * Return: power type on success, <0 on failure.
+ */
+static int cros_ec_usb_get_power_type(struct cros_ec_extcon_info *info)
+{
+       struct ec_params_usb_pd_power_info req;
+       struct ec_response_usb_pd_power_info resp;
+       int ret;
+
+       req.port = info->port_id;
+       ret = cros_ec_pd_command(info, EC_CMD_USB_PD_POWER_INFO, 0,
+                                &req, sizeof(req), &resp, sizeof(resp));
+       if (ret < 0)
+               return ret;
+
+       return resp.type;
+}
+
+/**
+ * cros_ec_usb_get_pd_mux_state() - Get PD mux state for given port.
+ * @info: pointer to struct cros_ec_extcon_info
+ *
+ * Return: PD mux state on success, <0 on failure.
+ */
+static int cros_ec_usb_get_pd_mux_state(struct cros_ec_extcon_info *info)
+{
+       struct ec_params_usb_pd_mux_info req;
+       struct ec_response_usb_pd_mux_info resp;
+       int ret;
+
+       req.port = info->port_id;
+       ret = cros_ec_pd_command(info, EC_CMD_USB_PD_MUX_INFO, 0,
+                                &req, sizeof(req),
+                                &resp, sizeof(resp));
+       if (ret < 0)
+               return ret;
+
+       return resp.flags;
+}
+
+/**
+ * cros_ec_usb_get_role() - Get role info about possible PD device attached to 
a
+ * given port.
+ * @info: pointer to struct cros_ec_extcon_info
+ * @polarity: pointer to cable polarity (return value)
+ *
+ * Return: role info on success, -ENOTCONN if no cable is connected, <0 on
+ * failure.
+ */
+static int cros_ec_usb_get_role(struct cros_ec_extcon_info *info,
+                               bool *polarity)
+{
+       struct ec_params_usb_pd_control pd_control;
+       struct ec_response_usb_pd_control_v1 resp;
+       int ret;
+
+       pd_control.port = info->port_id;
+       pd_control.role = USB_PD_CTRL_ROLE_NO_CHANGE;
+       pd_control.mux = USB_PD_CTRL_MUX_NO_CHANGE;
+       ret = cros_ec_pd_command(info, EC_CMD_USB_PD_CONTROL, 1,
+                                &pd_control, sizeof(pd_control),
+                                &resp, sizeof(resp));
+       if (ret < 0)
+               return ret;
+
+       if (!(resp.enabled & PD_CTRL_RESP_ENABLED_CONNECTED))
+               return -ENOTCONN;
+
+       *polarity = resp.polarity;
+
+       return resp.role;
+}
+
+/**
+ * cros_ec_pd_get_num_ports() - Get number of EC charge ports.
+ * @info: pointer to struct cros_ec_extcon_info
+ *
+ * Return: number of ports on success, <0 on failure.
+ */
+static int cros_ec_pd_get_num_ports(struct cros_ec_extcon_info *info)
+{
+       struct ec_response_usb_pd_ports resp;
+       int ret;
+
+       ret = cros_ec_pd_command(info, EC_CMD_USB_PD_PORTS,
+                                0, NULL, 0, &resp, sizeof(resp));
+       if (ret < 0)
+               return ret;
+
+       return resp.num_ports;
+}
+
+static int extcon_cros_ec_detect_cable(struct cros_ec_extcon_info *info,
+                                      bool force)
+{
+       struct device *dev = info->dev;
+       int role, power_type;
+       bool polarity = false;
+       bool dp = false;
+       bool mux = false;
+       bool hpd = false;
+
+       power_type = cros_ec_usb_get_power_type(info);
+       if (power_type < 0) {
+               dev_err(dev, "failed getting power type err = %d\n",
+                       power_type);
+               return power_type;
+       }
+
+       role = cros_ec_usb_get_role(info, &polarity);
+       if (role < 0) {
+               if (role != -ENOTCONN) {
+                       dev_err(dev, "failed getting role err = %d\n", role);
+                       return role;
+               }
+       } else {
+               int pd_mux_state;
+
+               pd_mux_state = cros_ec_usb_get_pd_mux_state(info);
+               if (pd_mux_state < 0)
+                       pd_mux_state = USB_PD_MUX_USB_ENABLED;
+
+               dp = pd_mux_state & USB_PD_MUX_DP_ENABLED;
+               mux = pd_mux_state & USB_PD_MUX_USB_ENABLED;
+               hpd = pd_mux_state & USB_PD_MUX_HPD_IRQ;
+       }
+
+       if (force || info->dp != dp || info->mux != mux ||
+               info->power_type != power_type) {
+
+               info->dp = dp;
+               info->mux = mux;
+               info->power_type = power_type;
+
+               extcon_set_state(info->edev, EXTCON_DISP_DP, dp);
+
+               extcon_set_property(info->edev, EXTCON_DISP_DP,
+                                   EXTCON_PROP_USB_TYPEC_POLARITY,
+                                   (union extcon_property_value)(int)polarity);
+               extcon_set_property(info->edev, EXTCON_DISP_DP,
+                                   EXTCON_PROP_USB_SS,
+                                   (union extcon_property_value)(int)mux);
+               extcon_set_property(info->edev, EXTCON_DISP_DP,
+                                   EXTCON_PROP_DISP_HPD,
+                                   (union extcon_property_value)(int)hpd);
+
+               extcon_sync(info->edev, EXTCON_DISP_DP);
+
+       } else if (hpd) {
+               extcon_set_property(info->edev, EXTCON_DISP_DP,
+                                   EXTCON_PROP_DISP_HPD,
+                                   (union extcon_property_value)(int)hpd);
+               extcon_sync(info->edev, EXTCON_DISP_DP);
+       }
+
+       return 0;
+}
+
+static int extcon_cros_ec_event(struct notifier_block *nb,
+                               unsigned long queued_during_suspend,
+                               void *_notify)
+{
+       struct cros_ec_extcon_info *info;
+       struct cros_ec_device *ec;
+       u32 host_event;
+
+       info = container_of(nb, struct cros_ec_extcon_info, notifier);
+       ec = info->ec;
+
+       host_event = cros_ec_get_host_event(ec);
+       if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
+                         EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) {
+               extcon_cros_ec_detect_cable(info, false);
+               return NOTIFY_OK;
+       }
+
+       return NOTIFY_DONE;
+}
+
+static int extcon_cros_ec_probe(struct platform_device *pdev)
+{
+       struct cros_ec_extcon_info *info;
+       struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
+       struct device *dev = &pdev->dev;
+       struct device_node *np = dev->of_node;
+       int numports, ret;
+
+       info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
+       if (!info)
+               return -ENOMEM;
+
+       info->dev = dev;
+       info->ec = ec;
+
+       if (np) {
+               u32 port;
+
+               ret = of_property_read_u32(np, "google,usb-port-id", &port);
+               if (ret < 0) {
+                       dev_err(dev, "Missing google,usb-port-id property\n");
+                       return ret;
+               }
+               info->port_id = port;
+       } else {
+               info->port_id = pdev->id;
+       }
+
+       numports = cros_ec_pd_get_num_ports(info);
+       if (numports < 0) {
+               dev_err(dev, "failed getting number of ports! ret = %d\n",
+                       numports);
+               return numports;
+       }
+
+       if (info->port_id >= numports) {
+               dev_err(dev, "This system only supports %d ports\n", numports);
+               return -ENODEV;
+       }
+
+       info->edev = devm_extcon_dev_allocate(dev, usb_type_c_cable);
+       if (IS_ERR(info->edev)) {
+               dev_err(dev, "failed to allocate extcon device\n");
+               return -ENOMEM;
+       }
+
+       ret = devm_extcon_dev_register(dev, info->edev);
+       if (ret < 0) {
+               dev_err(dev, "failed to register extcon device\n");
+               return ret;
+       }
+
+       extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
+                                      EXTCON_PROP_USB_TYPEC_POLARITY);
+       extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
+                                      EXTCON_PROP_USB_SS);
+       extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
+                                      EXTCON_PROP_DISP_HPD);
+
+       platform_set_drvdata(pdev, info);
+
+       /* Get PD events from the EC */
+       info->notifier.notifier_call = extcon_cros_ec_event;
+       ret = blocking_notifier_chain_register(&info->ec->event_notifier,
+                                              &info->notifier);
+       if (ret < 0) {
+               dev_err(dev, "failed to register notifier\n");
+               return ret;
+       }
+
+       /* Perform initial detection */
+       ret = extcon_cros_ec_detect_cable(info, true);
+       if (ret < 0) {
+               dev_err(dev, "failed to detect initial cable state\n");
+               goto unregister_notifier;
+       }
+
+       return 0;
+
+unregister_notifier:
+       blocking_notifier_chain_unregister(&info->ec->event_notifier,
+                                          &info->notifier);
+       return ret;
+}
+
+static int extcon_cros_ec_remove(struct platform_device *pdev)
+{
+       struct cros_ec_extcon_info *info = platform_get_drvdata(pdev);
+
+       blocking_notifier_chain_unregister(&info->ec->event_notifier,
+                                          &info->notifier);
+
+       return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int extcon_cros_ec_suspend(struct device *dev)
+{
+       return 0;
+}
+
+static int extcon_cros_ec_resume(struct device *dev)
+{
+       int ret;
+       struct cros_ec_extcon_info *info = dev_get_drvdata(dev);
+
+       ret = extcon_cros_ec_detect_cable(info, true);
+       if (ret < 0)
+               dev_err(dev, "failed to detect cable state on resume\n");
+
+       return 0;
+}
+
+static const struct dev_pm_ops extcon_cros_ec_dev_pm_ops = {
+       SET_SYSTEM_SLEEP_PM_OPS(extcon_cros_ec_suspend, extcon_cros_ec_resume)
+};
+
+#define DEV_PM_OPS     (&extcon_cros_ec_dev_pm_ops)
+#else
+#define DEV_PM_OPS     NULL
+#endif /* CONFIG_PM_SLEEP */
+
+#ifdef CONFIG_OF
+static const struct of_device_id extcon_cros_ec_of_match[] = {
+       { .compatible = "google,extcon-usbc-cros-ec" },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, extcon_cros_ec_of_match);
+#endif /* CONFIG_OF */
+
+static struct platform_driver extcon_cros_ec_driver = {
+       .driver = {
+               .name  = "extcon-usbc-cros-ec",
+               .of_match_table = of_match_ptr(extcon_cros_ec_of_match),
+               .pm = DEV_PM_OPS,
+       },
+       .remove  = extcon_cros_ec_remove,
+       .probe   = extcon_cros_ec_probe,
+};
+
+module_platform_driver(extcon_cros_ec_driver);
+
+MODULE_DESCRIPTION("ChromeOS Embedded Controller extcon driver");
+MODULE_AUTHOR("Benson Leung <ble...@chromium.org>");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/cros_ec_commands.h 
b/include/linux/mfd/cros_ec_commands.h
index 255d14a..3ca9953 100644
--- a/include/linux/mfd/cros_ec_commands.h
+++ b/include/linux/mfd/cros_ec_commands.h
@@ -285,10 +285,15 @@ enum host_event_code {
        EC_HOST_EVENT_HANG_DETECT = 20,
        /* Hang detect logic detected a hang and warm rebooted the AP */
        EC_HOST_EVENT_HANG_REBOOT = 21,
+       /* PD MCU triggering host event */
+       EC_HOST_EVENT_PD_MCU = 22,
 
        /* EC RTC event occurred */
        EC_HOST_EVENT_RTC = 26,
 
+       /* EC desires to change state of host-controlled USB mux */
+       EC_HOST_EVENT_USB_MUX = 28,
+
        /*
         * The high bit of the event mask is not used as a host event code.  If
         * it reads back as set, then the entire event mask should be
@@ -2873,6 +2878,76 @@ struct ec_params_usb_pd_control {
        uint8_t mux;
 } __packed;
 
+#define PD_CTRL_RESP_ENABLED_COMMS      (1 << 0) /* Communication enabled */
+#define PD_CTRL_RESP_ENABLED_CONNECTED  (1 << 1) /* Device connected */
+#define PD_CTRL_RESP_ENABLED_PD_CAPABLE (1 << 2) /* Partner is PD capable */
+
+struct ec_response_usb_pd_control_v1 {
+       uint8_t enabled;
+       uint8_t role;
+       uint8_t polarity;
+       char state[32];
+} __packed;
+
+#define EC_CMD_USB_PD_PORTS 0x102
+
+struct ec_response_usb_pd_ports {
+       uint8_t num_ports;
+} __packed;
+
+#define EC_CMD_USB_PD_POWER_INFO 0x103
+
+#define PD_POWER_CHARGING_PORT 0xff
+struct ec_params_usb_pd_power_info {
+       uint8_t port;
+} __packed;
+
+enum usb_chg_type {
+       USB_CHG_TYPE_NONE,
+       USB_CHG_TYPE_PD,
+       USB_CHG_TYPE_C,
+       USB_CHG_TYPE_PROPRIETARY,
+       USB_CHG_TYPE_BC12_DCP,
+       USB_CHG_TYPE_BC12_CDP,
+       USB_CHG_TYPE_BC12_SDP,
+       USB_CHG_TYPE_OTHER,
+       USB_CHG_TYPE_VBUS,
+       USB_CHG_TYPE_UNKNOWN,
+};
+
+struct usb_chg_measures {
+       uint16_t voltage_max;
+       uint16_t voltage_now;
+       uint16_t current_max;
+       uint16_t current_lim;
+} __packed;
+
+struct ec_response_usb_pd_power_info {
+       uint8_t role;
+       uint8_t type;
+       uint8_t dualrole;
+       uint8_t reserved1;
+       struct usb_chg_measures meas;
+       uint32_t max_power;
+} __packed;
+
+/* Get info about USB-C SS muxes */
+#define EC_CMD_USB_PD_MUX_INFO 0x11a
+
+struct ec_params_usb_pd_mux_info {
+       uint8_t port; /* USB-C port number */
+} __packed;
+
+/* Flags representing mux state */
+#define USB_PD_MUX_USB_ENABLED       (1 << 0)
+#define USB_PD_MUX_DP_ENABLED        (1 << 1)
+#define USB_PD_MUX_POLARITY_INVERTED (1 << 2)
+#define USB_PD_MUX_HPD_IRQ           (1 << 3)
+
+struct ec_response_usb_pd_mux_info {
+       uint8_t flags; /* USB_PD_MUX_*-encoded USB mux state */
+} __packed;
+
 /*****************************************************************************/
 /*
  * Passthru commands
-- 
2.9.3

Reply via email to