| Message ID | 20241204194900.371696-3-ukaszb@chromium.org |
|---|---|
| State | New |
| Headers | show |
| Series | usb: typec: Implement UCSI driver for ChromeOS | expand |
On Wed, Dec 04, 2024 at 07:49:00PM +0000, Łukasz Bartosik wrote: > From: Pavan Holla <pholla@chromium.org> > > Implementation of a UCSI transport driver for ChromeOS. > This driver will be loaded if the ChromeOS EC implements a PPM. > > Signed-off-by: Pavan Holla <pholla@chromium.org> > Co-developed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> > Co-developed-by: Łukasz Bartosik <ukaszb@chromium.org> > Signed-off-by: Łukasz Bartosik <ukaszb@chromium.org> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> > --- > MAINTAINERS | 7 + > drivers/usb/typec/ucsi/Kconfig | 13 + > drivers/usb/typec/ucsi/Makefile | 1 + > drivers/usb/typec/ucsi/cros_ec_ucsi.c | 337 ++++++++++++++++++++++++++ > 4 files changed, 358 insertions(+) > create mode 100644 drivers/usb/typec/ucsi/cros_ec_ucsi.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 1e930c7a58b1..36eebe1ad078 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -5452,6 +5452,13 @@ L: chrome-platform@lists.linux.dev > S: Maintained > F: drivers/watchdog/cros_ec_wdt.c > > +CHROMEOS UCSI DRIVER > +M: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> > +M: Łukasz Bartosik <ukaszb@chromium.org> > +L: chrome-platform@lists.linux.dev > +S: Maintained > +F: drivers/usb/typec/ucsi/cros_ec_ucsi.c > + > CHRONTEL CH7322 CEC DRIVER > M: Joe Tessler <jrt@google.com> > L: linux-media@vger.kernel.org > diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig > index 680e1b87b152..75559601fe8f 100644 > --- a/drivers/usb/typec/ucsi/Kconfig > +++ b/drivers/usb/typec/ucsi/Kconfig > @@ -69,6 +69,19 @@ config UCSI_PMIC_GLINK > To compile the driver as a module, choose M here: the module will be > called ucsi_glink. > > +config CROS_EC_UCSI > + tristate "UCSI Driver for ChromeOS EC" > + depends on MFD_CROS_EC_DEV > + depends on CROS_USBPD_NOTIFY > + depends on !EXTCON_TCSS_CROS_EC > + default MFD_CROS_EC_DEV > + help > + This driver enables UCSI support for a ChromeOS EC. The EC is > + expected to implement a PPM. > + > + To compile the driver as a module, choose M here: the module > + will be called cros_ec_ucsi. > + > config UCSI_LENOVO_YOGA_C630 > tristate "UCSI Interface Driver for Lenovo Yoga C630" > depends on EC_LENOVO_YOGA_C630 > diff --git a/drivers/usb/typec/ucsi/Makefile b/drivers/usb/typec/ucsi/Makefile > index aed41d23887b..be98a879104d 100644 > --- a/drivers/usb/typec/ucsi/Makefile > +++ b/drivers/usb/typec/ucsi/Makefile > @@ -21,4 +21,5 @@ obj-$(CONFIG_UCSI_ACPI) += ucsi_acpi.o > obj-$(CONFIG_UCSI_CCG) += ucsi_ccg.o > obj-$(CONFIG_UCSI_STM32G0) += ucsi_stm32g0.o > obj-$(CONFIG_UCSI_PMIC_GLINK) += ucsi_glink.o > +obj-$(CONFIG_CROS_EC_UCSI) += cros_ec_ucsi.o > obj-$(CONFIG_UCSI_LENOVO_YOGA_C630) += ucsi_yoga_c630.o > diff --git a/drivers/usb/typec/ucsi/cros_ec_ucsi.c b/drivers/usb/typec/ucsi/cros_ec_ucsi.c > new file mode 100644 > index 000000000000..cd2231d6a0ea > --- /dev/null > +++ b/drivers/usb/typec/ucsi/cros_ec_ucsi.c > @@ -0,0 +1,337 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * UCSI driver for ChromeOS EC > + * > + * Copyright 2024 Google LLC. > + */ > + > +#include <linux/container_of.h> > +#include <linux/dev_printk.h> > +#include <linux/jiffies.h> > +#include <linux/mod_devicetable.h> > +#include <linux/module.h> > +#include <linux/platform_data/cros_ec_commands.h> > +#include <linux/platform_data/cros_usbpd_notify.h> > +#include <linux/platform_data/cros_ec_proto.h> > +#include <linux/platform_device.h> > +#include <linux/slab.h> > +#include <linux/wait.h> > + > +#include "ucsi.h" > + > +/* > + * Maximum size in bytes of a UCSI message between AP and EC > + */ > +#define MAX_EC_DATA_SIZE 256 > + > +/* > + * Maximum time in milliseconds the cros_ec_ucsi driver > + * will wait for a response to a command or and ack. > + */ > +#define WRITE_TMO_MS 5000 > + > +/* Number of times to attempt recovery from a write timeout before giving up. */ > +#define WRITE_TMO_CTR_MAX 5 > + > +struct cros_ucsi_data { > + struct device *dev; > + struct ucsi *ucsi; > + > + struct cros_ec_device *ec; > + struct notifier_block nb; > + struct work_struct work; > + struct delayed_work write_tmo; > + int tmo_counter; > + > + struct completion complete; > + unsigned long flags; > +}; > + > +static int cros_ucsi_read(struct ucsi *ucsi, unsigned int offset, void *val, > + size_t val_len) > +{ > + struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi); > + struct ec_params_ucsi_ppm_get req = { > + .offset = offset, > + .size = val_len, > + }; > + int ret; > + > + if (val_len > MAX_EC_DATA_SIZE) { > + dev_err(udata->dev, "Can't read %zu bytes. Too big.", val_len); > + return -EINVAL; > + } > + > + ret = cros_ec_cmd(udata->ec, 0, EC_CMD_UCSI_PPM_GET, > + &req, sizeof(req), val, val_len); > + if (ret < 0) { > + dev_warn(udata->dev, "Failed to send EC message UCSI_PPM_GET: error=%d", ret); > + return ret; > + } > + return 0; > +} > + > +static int cros_ucsi_read_version(struct ucsi *ucsi, u16 *version) > +{ > + return cros_ucsi_read(ucsi, UCSI_VERSION, version, sizeof(*version)); > +} > + > +static int cros_ucsi_read_cci(struct ucsi *ucsi, u32 *cci) > +{ > + return cros_ucsi_read(ucsi, UCSI_CCI, cci, sizeof(*cci)); > +} > + > +static int cros_ucsi_read_message_in(struct ucsi *ucsi, void *val, > + size_t val_len) > +{ > + return cros_ucsi_read(ucsi, UCSI_MESSAGE_IN, val, val_len); > +} > + > +static int cros_ucsi_async_control(struct ucsi *ucsi, u64 cmd) > +{ > + struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi); > + u8 ec_buf[sizeof(struct ec_params_ucsi_ppm_set) + sizeof(cmd)]; > + struct ec_params_ucsi_ppm_set *req = (struct ec_params_ucsi_ppm_set *) ec_buf; > + int ret; > + > + req->offset = UCSI_CONTROL; > + memcpy(req->data, &cmd, sizeof(cmd)); > + ret = cros_ec_cmd(udata->ec, 0, EC_CMD_UCSI_PPM_SET, > + req, sizeof(ec_buf), NULL, 0); > + if (ret < 0) { > + dev_warn(udata->dev, "Failed to send EC message UCSI_PPM_SET: error=%d", ret); > + return ret; > + } > + return 0; > +} > + > +static int cros_ucsi_sync_control(struct ucsi *ucsi, u64 cmd) > +{ > + struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi); > + int ret; > + > + ret = ucsi_sync_control_common(ucsi, cmd); > + switch (ret) { > + case -EBUSY: > + /* EC may return -EBUSY if CCI.busy is set. > + * Convert this to a timeout. > + */ > + case -ETIMEDOUT: > + /* Schedule recovery attempt when we timeout > + * or tried to send a command while still busy. > + */ > + cancel_delayed_work_sync(&udata->write_tmo); > + schedule_delayed_work(&udata->write_tmo, > + msecs_to_jiffies(WRITE_TMO_MS)); > + break; > + case 0: > + /* Successful write. Cancel any pending recovery work. */ > + cancel_delayed_work_sync(&udata->write_tmo); > + break; > + } > + > + return ret; > +} > + > +struct ucsi_operations cros_ucsi_ops = { > + .read_version = cros_ucsi_read_version, > + .read_cci = cros_ucsi_read_cci, > + .read_message_in = cros_ucsi_read_message_in, > + .async_control = cros_ucsi_async_control, > + .sync_control = cros_ucsi_sync_control, > +}; > + > +static void cros_ucsi_work(struct work_struct *work) > +{ > + struct cros_ucsi_data *udata = container_of(work, struct cros_ucsi_data, work); > + u32 cci; > + > + if (cros_ucsi_read_cci(udata->ucsi, &cci)) > + return; > + > + ucsi_notify_common(udata->ucsi, cci); > +} > + > +static void cros_ucsi_write_timeout(struct work_struct *work) > +{ > + struct cros_ucsi_data *udata = > + container_of(work, struct cros_ucsi_data, write_tmo.work); > + u32 cci; > + u64 cmd; > + > + if (cros_ucsi_read(udata->ucsi, UCSI_CCI, &cci, sizeof(cci))) { > + dev_err(udata->dev, > + "Reading CCI failed; no write timeout recovery possible."); > + return; > + } > + > + if (cci & UCSI_CCI_BUSY) { > + udata->tmo_counter++; > + > + if (udata->tmo_counter <= WRITE_TMO_CTR_MAX) > + schedule_delayed_work(&udata->write_tmo, > + msecs_to_jiffies(WRITE_TMO_MS)); > + else > + dev_err(udata->dev, > + "PPM unresponsive - too many write timeouts."); > + > + return; > + } > + > + /* No longer busy means we can reset our timeout counter. */ > + udata->tmo_counter = 0; > + > + /* Need to ack previous command which may have timed out. */ > + if (cci & UCSI_CCI_COMMAND_COMPLETE) { > + cmd = UCSI_ACK_CC_CI | UCSI_ACK_COMMAND_COMPLETE; > + cros_ucsi_async_control(udata->ucsi, &cmd); > + > + /* Check again after a few seconds that the system has > + * recovered to make sure our async write above was successful. > + */ > + schedule_delayed_work(&udata->write_tmo, > + msecs_to_jiffies(WRITE_TMO_MS)); > + return; > + } > + > + /* We recovered from a previous timeout. Treat this as a recovery from > + * suspend and call resume. > + */ > + ucsi_resume(udata->ucsi); > +} > + > +static int cros_ucsi_event(struct notifier_block *nb, > + unsigned long host_event, void *_notify) > +{ > + struct cros_ucsi_data *udata = container_of(nb, struct cros_ucsi_data, nb); > + > + if (!(host_event & PD_EVENT_PPM)) > + return NOTIFY_OK; > + > + dev_dbg(udata->dev, "UCSI notification received"); > + flush_work(&udata->work); > + schedule_work(&udata->work); > + > + return NOTIFY_OK; > +} > + > +static void cros_ucsi_destroy(struct cros_ucsi_data *udata) > +{ > + cros_usbpd_unregister_notify(&udata->nb); > + cancel_delayed_work(&udata->write_tmo); > + cancel_work_sync(&udata->work); > + ucsi_destroy(udata->ucsi); > +} > + > +static int cros_ucsi_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct cros_ec_dev *ec_data = dev_get_drvdata(dev->parent); > + struct cros_ucsi_data *udata; > + int ret; > + > + udata = devm_kzalloc(dev, sizeof(*udata), GFP_KERNEL); > + if (!udata) > + return -ENOMEM; > + > + udata->dev = dev; > + > + udata->ec = ec_data->ec_dev; > + if (!udata->ec) { > + dev_err(dev, "couldn't find parent EC device"); > + return -ENODEV; > + } > + > + platform_set_drvdata(pdev, udata); > + > + INIT_WORK(&udata->work, cros_ucsi_work); > + INIT_DELAYED_WORK(&udata->write_tmo, cros_ucsi_write_timeout); > + init_completion(&udata->complete); > + > + udata->ucsi = ucsi_create(dev, &cros_ucsi_ops); > + if (IS_ERR(udata->ucsi)) { > + dev_err(dev, "failed to allocate UCSI instance"); > + return PTR_ERR(udata->ucsi); > + } > + > + ucsi_set_drvdata(udata->ucsi, udata); > + > + udata->nb.notifier_call = cros_ucsi_event; > + ret = cros_usbpd_register_notify(&udata->nb); > + if (ret) { > + dev_err(dev, "failed to register notifier: error=%d", ret); > + ucsi_destroy(udata->ucsi); > + return ret; > + } > + > + ret = ucsi_register(udata->ucsi); > + if (ret) { > + dev_err(dev, "failed to register UCSI: error=%d", ret); > + cros_ucsi_destroy(udata); > + return ret; > + } > + > + return 0; > +} > + > +static void cros_ucsi_remove(struct platform_device *dev) > +{ > + struct cros_ucsi_data *udata = platform_get_drvdata(dev); > + > + ucsi_unregister(udata->ucsi); > + cros_ucsi_destroy(udata); > +} > + > +static int __maybe_unused cros_ucsi_suspend(struct device *dev) > +{ > + struct cros_ucsi_data *udata = dev_get_drvdata(dev); > + > + cancel_delayed_work(&udata->write_tmo); > + cancel_work_sync(&udata->work); > + > + return 0; > +} > + > +static void __maybe_unused cros_ucsi_complete(struct device *dev) > +{ > + struct cros_ucsi_data *udata = dev_get_drvdata(dev); > + > + ucsi_resume(udata->ucsi); > +} > + > +/* > + * UCSI protocol is also used on ChromeOS platforms which reply on > + * cros_ec_lpc.c driver for communication with embedded controller (EC). > + * On such platforms communication with the EC is not available until > + * the .complete() callback of the cros_ec_lpc driver is executed. > + * For this reason we delay ucsi_resume() until the .complete() stage > + * otherwise UCSI SET_NOTIFICATION_ENABLE command will fail and we won't > + * receive any UCSI notifications from the EC where PPM is implemented. > + */ > +static const struct dev_pm_ops cros_ucsi_pm_ops = { > +#ifdef CONFIG_PM_SLEEP > + .suspend = cros_ucsi_suspend, > + .complete = cros_ucsi_complete, > +#endif > +}; > + > +static const struct platform_device_id cros_ucsi_id[] = { > + { KBUILD_MODNAME, 0 }, > + {} > +}; > +MODULE_DEVICE_TABLE(platform, cros_ucsi_id); > + > +static struct platform_driver cros_ucsi_driver = { > + .driver = { > + .name = KBUILD_MODNAME, > + .pm = &cros_ucsi_pm_ops, > + }, > + .id_table = cros_ucsi_id, > + .probe = cros_ucsi_probe, > + .remove = cros_ucsi_remove, > +}; > + > +module_platform_driver(cros_ucsi_driver); > + > +MODULE_LICENSE("GPL"); > +MODULE_DESCRIPTION("UCSI driver for ChromeOS EC"); > -- > 2.47.0.338.g60cca15819-goog
diff --git a/MAINTAINERS b/MAINTAINERS index 1e930c7a58b1..36eebe1ad078 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5452,6 +5452,13 @@ L: chrome-platform@lists.linux.dev S: Maintained F: drivers/watchdog/cros_ec_wdt.c +CHROMEOS UCSI DRIVER +M: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> +M: Łukasz Bartosik <ukaszb@chromium.org> +L: chrome-platform@lists.linux.dev +S: Maintained +F: drivers/usb/typec/ucsi/cros_ec_ucsi.c + CHRONTEL CH7322 CEC DRIVER M: Joe Tessler <jrt@google.com> L: linux-media@vger.kernel.org diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig index 680e1b87b152..75559601fe8f 100644 --- a/drivers/usb/typec/ucsi/Kconfig +++ b/drivers/usb/typec/ucsi/Kconfig @@ -69,6 +69,19 @@ config UCSI_PMIC_GLINK To compile the driver as a module, choose M here: the module will be called ucsi_glink. +config CROS_EC_UCSI + tristate "UCSI Driver for ChromeOS EC" + depends on MFD_CROS_EC_DEV + depends on CROS_USBPD_NOTIFY + depends on !EXTCON_TCSS_CROS_EC + default MFD_CROS_EC_DEV + help + This driver enables UCSI support for a ChromeOS EC. The EC is + expected to implement a PPM. + + To compile the driver as a module, choose M here: the module + will be called cros_ec_ucsi. + config UCSI_LENOVO_YOGA_C630 tristate "UCSI Interface Driver for Lenovo Yoga C630" depends on EC_LENOVO_YOGA_C630 diff --git a/drivers/usb/typec/ucsi/Makefile b/drivers/usb/typec/ucsi/Makefile index aed41d23887b..be98a879104d 100644 --- a/drivers/usb/typec/ucsi/Makefile +++ b/drivers/usb/typec/ucsi/Makefile @@ -21,4 +21,5 @@ obj-$(CONFIG_UCSI_ACPI) += ucsi_acpi.o obj-$(CONFIG_UCSI_CCG) += ucsi_ccg.o obj-$(CONFIG_UCSI_STM32G0) += ucsi_stm32g0.o obj-$(CONFIG_UCSI_PMIC_GLINK) += ucsi_glink.o +obj-$(CONFIG_CROS_EC_UCSI) += cros_ec_ucsi.o obj-$(CONFIG_UCSI_LENOVO_YOGA_C630) += ucsi_yoga_c630.o diff --git a/drivers/usb/typec/ucsi/cros_ec_ucsi.c b/drivers/usb/typec/ucsi/cros_ec_ucsi.c new file mode 100644 index 000000000000..cd2231d6a0ea --- /dev/null +++ b/drivers/usb/typec/ucsi/cros_ec_ucsi.c @@ -0,0 +1,337 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * UCSI driver for ChromeOS EC + * + * Copyright 2024 Google LLC. + */ + +#include <linux/container_of.h> +#include <linux/dev_printk.h> +#include <linux/jiffies.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/platform_data/cros_ec_commands.h> +#include <linux/platform_data/cros_usbpd_notify.h> +#include <linux/platform_data/cros_ec_proto.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/wait.h> + +#include "ucsi.h" + +/* + * Maximum size in bytes of a UCSI message between AP and EC + */ +#define MAX_EC_DATA_SIZE 256 + +/* + * Maximum time in milliseconds the cros_ec_ucsi driver + * will wait for a response to a command or and ack. + */ +#define WRITE_TMO_MS 5000 + +/* Number of times to attempt recovery from a write timeout before giving up. */ +#define WRITE_TMO_CTR_MAX 5 + +struct cros_ucsi_data { + struct device *dev; + struct ucsi *ucsi; + + struct cros_ec_device *ec; + struct notifier_block nb; + struct work_struct work; + struct delayed_work write_tmo; + int tmo_counter; + + struct completion complete; + unsigned long flags; +}; + +static int cros_ucsi_read(struct ucsi *ucsi, unsigned int offset, void *val, + size_t val_len) +{ + struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi); + struct ec_params_ucsi_ppm_get req = { + .offset = offset, + .size = val_len, + }; + int ret; + + if (val_len > MAX_EC_DATA_SIZE) { + dev_err(udata->dev, "Can't read %zu bytes. Too big.", val_len); + return -EINVAL; + } + + ret = cros_ec_cmd(udata->ec, 0, EC_CMD_UCSI_PPM_GET, + &req, sizeof(req), val, val_len); + if (ret < 0) { + dev_warn(udata->dev, "Failed to send EC message UCSI_PPM_GET: error=%d", ret); + return ret; + } + return 0; +} + +static int cros_ucsi_read_version(struct ucsi *ucsi, u16 *version) +{ + return cros_ucsi_read(ucsi, UCSI_VERSION, version, sizeof(*version)); +} + +static int cros_ucsi_read_cci(struct ucsi *ucsi, u32 *cci) +{ + return cros_ucsi_read(ucsi, UCSI_CCI, cci, sizeof(*cci)); +} + +static int cros_ucsi_read_message_in(struct ucsi *ucsi, void *val, + size_t val_len) +{ + return cros_ucsi_read(ucsi, UCSI_MESSAGE_IN, val, val_len); +} + +static int cros_ucsi_async_control(struct ucsi *ucsi, u64 cmd) +{ + struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi); + u8 ec_buf[sizeof(struct ec_params_ucsi_ppm_set) + sizeof(cmd)]; + struct ec_params_ucsi_ppm_set *req = (struct ec_params_ucsi_ppm_set *) ec_buf; + int ret; + + req->offset = UCSI_CONTROL; + memcpy(req->data, &cmd, sizeof(cmd)); + ret = cros_ec_cmd(udata->ec, 0, EC_CMD_UCSI_PPM_SET, + req, sizeof(ec_buf), NULL, 0); + if (ret < 0) { + dev_warn(udata->dev, "Failed to send EC message UCSI_PPM_SET: error=%d", ret); + return ret; + } + return 0; +} + +static int cros_ucsi_sync_control(struct ucsi *ucsi, u64 cmd) +{ + struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi); + int ret; + + ret = ucsi_sync_control_common(ucsi, cmd); + switch (ret) { + case -EBUSY: + /* EC may return -EBUSY if CCI.busy is set. + * Convert this to a timeout. + */ + case -ETIMEDOUT: + /* Schedule recovery attempt when we timeout + * or tried to send a command while still busy. + */ + cancel_delayed_work_sync(&udata->write_tmo); + schedule_delayed_work(&udata->write_tmo, + msecs_to_jiffies(WRITE_TMO_MS)); + break; + case 0: + /* Successful write. Cancel any pending recovery work. */ + cancel_delayed_work_sync(&udata->write_tmo); + break; + } + + return ret; +} + +struct ucsi_operations cros_ucsi_ops = { + .read_version = cros_ucsi_read_version, + .read_cci = cros_ucsi_read_cci, + .read_message_in = cros_ucsi_read_message_in, + .async_control = cros_ucsi_async_control, + .sync_control = cros_ucsi_sync_control, +}; + +static void cros_ucsi_work(struct work_struct *work) +{ + struct cros_ucsi_data *udata = container_of(work, struct cros_ucsi_data, work); + u32 cci; + + if (cros_ucsi_read_cci(udata->ucsi, &cci)) + return; + + ucsi_notify_common(udata->ucsi, cci); +} + +static void cros_ucsi_write_timeout(struct work_struct *work) +{ + struct cros_ucsi_data *udata = + container_of(work, struct cros_ucsi_data, write_tmo.work); + u32 cci; + u64 cmd; + + if (cros_ucsi_read(udata->ucsi, UCSI_CCI, &cci, sizeof(cci))) { + dev_err(udata->dev, + "Reading CCI failed; no write timeout recovery possible."); + return; + } + + if (cci & UCSI_CCI_BUSY) { + udata->tmo_counter++; + + if (udata->tmo_counter <= WRITE_TMO_CTR_MAX) + schedule_delayed_work(&udata->write_tmo, + msecs_to_jiffies(WRITE_TMO_MS)); + else + dev_err(udata->dev, + "PPM unresponsive - too many write timeouts."); + + return; + } + + /* No longer busy means we can reset our timeout counter. */ + udata->tmo_counter = 0; + + /* Need to ack previous command which may have timed out. */ + if (cci & UCSI_CCI_COMMAND_COMPLETE) { + cmd = UCSI_ACK_CC_CI | UCSI_ACK_COMMAND_COMPLETE; + cros_ucsi_async_control(udata->ucsi, &cmd); + + /* Check again after a few seconds that the system has + * recovered to make sure our async write above was successful. + */ + schedule_delayed_work(&udata->write_tmo, + msecs_to_jiffies(WRITE_TMO_MS)); + return; + } + + /* We recovered from a previous timeout. Treat this as a recovery from + * suspend and call resume. + */ + ucsi_resume(udata->ucsi); +} + +static int cros_ucsi_event(struct notifier_block *nb, + unsigned long host_event, void *_notify) +{ + struct cros_ucsi_data *udata = container_of(nb, struct cros_ucsi_data, nb); + + if (!(host_event & PD_EVENT_PPM)) + return NOTIFY_OK; + + dev_dbg(udata->dev, "UCSI notification received"); + flush_work(&udata->work); + schedule_work(&udata->work); + + return NOTIFY_OK; +} + +static void cros_ucsi_destroy(struct cros_ucsi_data *udata) +{ + cros_usbpd_unregister_notify(&udata->nb); + cancel_delayed_work(&udata->write_tmo); + cancel_work_sync(&udata->work); + ucsi_destroy(udata->ucsi); +} + +static int cros_ucsi_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct cros_ec_dev *ec_data = dev_get_drvdata(dev->parent); + struct cros_ucsi_data *udata; + int ret; + + udata = devm_kzalloc(dev, sizeof(*udata), GFP_KERNEL); + if (!udata) + return -ENOMEM; + + udata->dev = dev; + + udata->ec = ec_data->ec_dev; + if (!udata->ec) { + dev_err(dev, "couldn't find parent EC device"); + return -ENODEV; + } + + platform_set_drvdata(pdev, udata); + + INIT_WORK(&udata->work, cros_ucsi_work); + INIT_DELAYED_WORK(&udata->write_tmo, cros_ucsi_write_timeout); + init_completion(&udata->complete); + + udata->ucsi = ucsi_create(dev, &cros_ucsi_ops); + if (IS_ERR(udata->ucsi)) { + dev_err(dev, "failed to allocate UCSI instance"); + return PTR_ERR(udata->ucsi); + } + + ucsi_set_drvdata(udata->ucsi, udata); + + udata->nb.notifier_call = cros_ucsi_event; + ret = cros_usbpd_register_notify(&udata->nb); + if (ret) { + dev_err(dev, "failed to register notifier: error=%d", ret); + ucsi_destroy(udata->ucsi); + return ret; + } + + ret = ucsi_register(udata->ucsi); + if (ret) { + dev_err(dev, "failed to register UCSI: error=%d", ret); + cros_ucsi_destroy(udata); + return ret; + } + + return 0; +} + +static void cros_ucsi_remove(struct platform_device *dev) +{ + struct cros_ucsi_data *udata = platform_get_drvdata(dev); + + ucsi_unregister(udata->ucsi); + cros_ucsi_destroy(udata); +} + +static int __maybe_unused cros_ucsi_suspend(struct device *dev) +{ + struct cros_ucsi_data *udata = dev_get_drvdata(dev); + + cancel_delayed_work(&udata->write_tmo); + cancel_work_sync(&udata->work); + + return 0; +} + +static void __maybe_unused cros_ucsi_complete(struct device *dev) +{ + struct cros_ucsi_data *udata = dev_get_drvdata(dev); + + ucsi_resume(udata->ucsi); +} + +/* + * UCSI protocol is also used on ChromeOS platforms which reply on + * cros_ec_lpc.c driver for communication with embedded controller (EC). + * On such platforms communication with the EC is not available until + * the .complete() callback of the cros_ec_lpc driver is executed. + * For this reason we delay ucsi_resume() until the .complete() stage + * otherwise UCSI SET_NOTIFICATION_ENABLE command will fail and we won't + * receive any UCSI notifications from the EC where PPM is implemented. + */ +static const struct dev_pm_ops cros_ucsi_pm_ops = { +#ifdef CONFIG_PM_SLEEP + .suspend = cros_ucsi_suspend, + .complete = cros_ucsi_complete, +#endif +}; + +static const struct platform_device_id cros_ucsi_id[] = { + { KBUILD_MODNAME, 0 }, + {} +}; +MODULE_DEVICE_TABLE(platform, cros_ucsi_id); + +static struct platform_driver cros_ucsi_driver = { + .driver = { + .name = KBUILD_MODNAME, + .pm = &cros_ucsi_pm_ops, + }, + .id_table = cros_ucsi_id, + .probe = cros_ucsi_probe, + .remove = cros_ucsi_remove, +}; + +module_platform_driver(cros_ucsi_driver); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("UCSI driver for ChromeOS EC");