usb: typec: ucsi: Implement ChromeOS UCSI driver
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> Link: https://lore.kernel.org/r/20241231131047.1757434-3-ukaszb@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Pavan Holla
Greg Kroah-Hartman
parent
401d07d530
commit
f1a2241778
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@ -5457,6 +5457,13 @@ L: chrome-platform@lists.linux.dev
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S: Maintained
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F: drivers/watchdog/cros_ec_wdt.c
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CHROMEOS UCSI DRIVER
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M: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
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M: Łukasz Bartosik <ukaszb@chromium.org>
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L: chrome-platform@lists.linux.dev
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S: Maintained
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F: drivers/usb/typec/ucsi/cros_ec_ucsi.c
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CHRONTEL CH7322 CEC DRIVER
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M: Joe Tessler <jrt@google.com>
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L: linux-media@vger.kernel.org
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@ -69,6 +69,19 @@ config UCSI_PMIC_GLINK
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To compile the driver as a module, choose M here: the module will be
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called ucsi_glink.
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config CROS_EC_UCSI
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tristate "UCSI Driver for ChromeOS EC"
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depends on MFD_CROS_EC_DEV
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depends on CROS_USBPD_NOTIFY
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depends on !EXTCON_TCSS_CROS_EC
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default MFD_CROS_EC_DEV
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help
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This driver enables UCSI support for a ChromeOS EC. The EC is
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expected to implement a PPM.
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To compile the driver as a module, choose M here: the module
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will be called cros_ec_ucsi.
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config UCSI_LENOVO_YOGA_C630
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tristate "UCSI Interface Driver for Lenovo Yoga C630"
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depends on EC_LENOVO_YOGA_C630
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@ -21,4 +21,5 @@ obj-$(CONFIG_UCSI_ACPI) += ucsi_acpi.o
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obj-$(CONFIG_UCSI_CCG) += ucsi_ccg.o
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obj-$(CONFIG_UCSI_STM32G0) += ucsi_stm32g0.o
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obj-$(CONFIG_UCSI_PMIC_GLINK) += ucsi_glink.o
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obj-$(CONFIG_CROS_EC_UCSI) += cros_ec_ucsi.o
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obj-$(CONFIG_UCSI_LENOVO_YOGA_C630) += ucsi_yoga_c630.o
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@ -0,0 +1,337 @@
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// SPDX-License-Identifier: GPL-2.0
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/*
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* UCSI driver for ChromeOS EC
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*
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* Copyright 2024 Google LLC.
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*/
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#include <linux/container_of.h>
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#include <linux/dev_printk.h>
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#include <linux/jiffies.h>
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#include <linux/mod_devicetable.h>
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#include <linux/module.h>
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#include <linux/platform_data/cros_ec_commands.h>
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#include <linux/platform_data/cros_usbpd_notify.h>
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#include <linux/platform_data/cros_ec_proto.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/wait.h>
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#include "ucsi.h"
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/*
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* Maximum size in bytes of a UCSI message between AP and EC
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*/
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#define MAX_EC_DATA_SIZE 256
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/*
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* Maximum time in milliseconds the cros_ec_ucsi driver
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* will wait for a response to a command or and ack.
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*/
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#define WRITE_TMO_MS 5000
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/* Number of times to attempt recovery from a write timeout before giving up. */
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#define WRITE_TMO_CTR_MAX 5
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struct cros_ucsi_data {
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struct device *dev;
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struct ucsi *ucsi;
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struct cros_ec_device *ec;
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struct notifier_block nb;
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struct work_struct work;
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struct delayed_work write_tmo;
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int tmo_counter;
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struct completion complete;
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unsigned long flags;
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};
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static int cros_ucsi_read(struct ucsi *ucsi, unsigned int offset, void *val,
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size_t val_len)
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{
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struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi);
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struct ec_params_ucsi_ppm_get req = {
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.offset = offset,
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.size = val_len,
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};
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int ret;
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if (val_len > MAX_EC_DATA_SIZE) {
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dev_err(udata->dev, "Can't read %zu bytes. Too big.", val_len);
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return -EINVAL;
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}
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ret = cros_ec_cmd(udata->ec, 0, EC_CMD_UCSI_PPM_GET,
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&req, sizeof(req), val, val_len);
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if (ret < 0) {
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dev_warn(udata->dev, "Failed to send EC message UCSI_PPM_GET: error=%d", ret);
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return ret;
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}
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return 0;
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}
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static int cros_ucsi_read_version(struct ucsi *ucsi, u16 *version)
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{
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return cros_ucsi_read(ucsi, UCSI_VERSION, version, sizeof(*version));
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}
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static int cros_ucsi_read_cci(struct ucsi *ucsi, u32 *cci)
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{
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return cros_ucsi_read(ucsi, UCSI_CCI, cci, sizeof(*cci));
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}
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static int cros_ucsi_read_message_in(struct ucsi *ucsi, void *val,
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size_t val_len)
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{
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return cros_ucsi_read(ucsi, UCSI_MESSAGE_IN, val, val_len);
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}
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static int cros_ucsi_async_control(struct ucsi *ucsi, u64 cmd)
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{
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struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi);
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u8 ec_buf[sizeof(struct ec_params_ucsi_ppm_set) + sizeof(cmd)];
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struct ec_params_ucsi_ppm_set *req = (struct ec_params_ucsi_ppm_set *) ec_buf;
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int ret;
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req->offset = UCSI_CONTROL;
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memcpy(req->data, &cmd, sizeof(cmd));
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ret = cros_ec_cmd(udata->ec, 0, EC_CMD_UCSI_PPM_SET,
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req, sizeof(ec_buf), NULL, 0);
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if (ret < 0) {
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dev_warn(udata->dev, "Failed to send EC message UCSI_PPM_SET: error=%d", ret);
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return ret;
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}
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return 0;
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}
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static int cros_ucsi_sync_control(struct ucsi *ucsi, u64 cmd)
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{
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struct cros_ucsi_data *udata = ucsi_get_drvdata(ucsi);
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int ret;
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ret = ucsi_sync_control_common(ucsi, cmd);
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switch (ret) {
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case -EBUSY:
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/* EC may return -EBUSY if CCI.busy is set.
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* Convert this to a timeout.
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*/
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case -ETIMEDOUT:
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/* Schedule recovery attempt when we timeout
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* or tried to send a command while still busy.
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*/
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cancel_delayed_work_sync(&udata->write_tmo);
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schedule_delayed_work(&udata->write_tmo,
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msecs_to_jiffies(WRITE_TMO_MS));
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break;
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case 0:
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/* Successful write. Cancel any pending recovery work. */
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cancel_delayed_work_sync(&udata->write_tmo);
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break;
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}
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return ret;
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}
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struct ucsi_operations cros_ucsi_ops = {
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.read_version = cros_ucsi_read_version,
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.read_cci = cros_ucsi_read_cci,
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.read_message_in = cros_ucsi_read_message_in,
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.async_control = cros_ucsi_async_control,
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.sync_control = cros_ucsi_sync_control,
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};
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static void cros_ucsi_work(struct work_struct *work)
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{
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struct cros_ucsi_data *udata = container_of(work, struct cros_ucsi_data, work);
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u32 cci;
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if (cros_ucsi_read_cci(udata->ucsi, &cci))
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return;
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ucsi_notify_common(udata->ucsi, cci);
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}
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static void cros_ucsi_write_timeout(struct work_struct *work)
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{
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struct cros_ucsi_data *udata =
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container_of(work, struct cros_ucsi_data, write_tmo.work);
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u32 cci;
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u64 cmd;
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if (cros_ucsi_read(udata->ucsi, UCSI_CCI, &cci, sizeof(cci))) {
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dev_err(udata->dev,
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"Reading CCI failed; no write timeout recovery possible.");
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return;
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}
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if (cci & UCSI_CCI_BUSY) {
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udata->tmo_counter++;
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if (udata->tmo_counter <= WRITE_TMO_CTR_MAX)
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schedule_delayed_work(&udata->write_tmo,
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msecs_to_jiffies(WRITE_TMO_MS));
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else
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dev_err(udata->dev,
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"PPM unresponsive - too many write timeouts.");
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return;
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}
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/* No longer busy means we can reset our timeout counter. */
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udata->tmo_counter = 0;
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/* Need to ack previous command which may have timed out. */
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if (cci & UCSI_CCI_COMMAND_COMPLETE) {
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cmd = UCSI_ACK_CC_CI | UCSI_ACK_COMMAND_COMPLETE;
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cros_ucsi_async_control(udata->ucsi, cmd);
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/* Check again after a few seconds that the system has
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* recovered to make sure our async write above was successful.
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*/
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schedule_delayed_work(&udata->write_tmo,
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msecs_to_jiffies(WRITE_TMO_MS));
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return;
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}
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/* We recovered from a previous timeout. Treat this as a recovery from
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* suspend and call resume.
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*/
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ucsi_resume(udata->ucsi);
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}
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static int cros_ucsi_event(struct notifier_block *nb,
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unsigned long host_event, void *_notify)
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{
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struct cros_ucsi_data *udata = container_of(nb, struct cros_ucsi_data, nb);
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if (!(host_event & PD_EVENT_PPM))
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return NOTIFY_OK;
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dev_dbg(udata->dev, "UCSI notification received");
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flush_work(&udata->work);
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schedule_work(&udata->work);
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return NOTIFY_OK;
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}
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static void cros_ucsi_destroy(struct cros_ucsi_data *udata)
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{
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cros_usbpd_unregister_notify(&udata->nb);
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cancel_delayed_work_sync(&udata->write_tmo);
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cancel_work_sync(&udata->work);
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ucsi_destroy(udata->ucsi);
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}
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static int cros_ucsi_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct cros_ec_dev *ec_data = dev_get_drvdata(dev->parent);
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struct cros_ucsi_data *udata;
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int ret;
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udata = devm_kzalloc(dev, sizeof(*udata), GFP_KERNEL);
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if (!udata)
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return -ENOMEM;
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udata->dev = dev;
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udata->ec = ec_data->ec_dev;
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if (!udata->ec) {
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dev_err(dev, "couldn't find parent EC device");
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return -ENODEV;
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}
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platform_set_drvdata(pdev, udata);
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INIT_WORK(&udata->work, cros_ucsi_work);
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INIT_DELAYED_WORK(&udata->write_tmo, cros_ucsi_write_timeout);
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init_completion(&udata->complete);
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udata->ucsi = ucsi_create(dev, &cros_ucsi_ops);
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if (IS_ERR(udata->ucsi)) {
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dev_err(dev, "failed to allocate UCSI instance");
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return PTR_ERR(udata->ucsi);
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}
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ucsi_set_drvdata(udata->ucsi, udata);
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udata->nb.notifier_call = cros_ucsi_event;
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ret = cros_usbpd_register_notify(&udata->nb);
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if (ret) {
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dev_err(dev, "failed to register notifier: error=%d", ret);
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ucsi_destroy(udata->ucsi);
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return ret;
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}
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ret = ucsi_register(udata->ucsi);
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if (ret) {
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dev_err(dev, "failed to register UCSI: error=%d", ret);
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cros_ucsi_destroy(udata);
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return ret;
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}
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return 0;
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}
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static void cros_ucsi_remove(struct platform_device *dev)
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{
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struct cros_ucsi_data *udata = platform_get_drvdata(dev);
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ucsi_unregister(udata->ucsi);
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cros_ucsi_destroy(udata);
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}
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static int __maybe_unused cros_ucsi_suspend(struct device *dev)
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{
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struct cros_ucsi_data *udata = dev_get_drvdata(dev);
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cancel_delayed_work_sync(&udata->write_tmo);
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cancel_work_sync(&udata->work);
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return 0;
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}
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static void __maybe_unused cros_ucsi_complete(struct device *dev)
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{
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struct cros_ucsi_data *udata = dev_get_drvdata(dev);
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ucsi_resume(udata->ucsi);
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}
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/*
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* UCSI protocol is also used on ChromeOS platforms which reply on
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* cros_ec_lpc.c driver for communication with embedded controller (EC).
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* On such platforms communication with the EC is not available until
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* the .complete() callback of the cros_ec_lpc driver is executed.
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* For this reason we delay ucsi_resume() until the .complete() stage
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* otherwise UCSI SET_NOTIFICATION_ENABLE command will fail and we won't
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* receive any UCSI notifications from the EC where PPM is implemented.
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*/
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static const struct dev_pm_ops cros_ucsi_pm_ops = {
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#ifdef CONFIG_PM_SLEEP
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.suspend = cros_ucsi_suspend,
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.complete = cros_ucsi_complete,
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#endif
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};
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static const struct platform_device_id cros_ucsi_id[] = {
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{ KBUILD_MODNAME, 0 },
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{}
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};
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MODULE_DEVICE_TABLE(platform, cros_ucsi_id);
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static struct platform_driver cros_ucsi_driver = {
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.driver = {
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.name = KBUILD_MODNAME,
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.pm = &cros_ucsi_pm_ops,
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},
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.id_table = cros_ucsi_id,
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.probe = cros_ucsi_probe,
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.remove = cros_ucsi_remove,
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};
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module_platform_driver(cros_ucsi_driver);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("UCSI driver for ChromeOS EC");
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