Quelle  cros_usbpd_logger.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/*
 * Logging driver for ChromeOS EC based USBPD Charger.
 *
 * Copyright 2018 Google LLC.
 */

#include <linux/ktime.h>
#include <linux/math64.h>
#include <linux/mod_devicetable.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/rtc.h>
#include <linux/string_choices.h>

#define DRV_NAME "cros-usbpd-logger"

#define CROS_USBPD_MAX_LOG_ENTRIES 30
#define CROS_USBPD_LOG_UPDATE_DELAY msecs_to_jiffies(60000)
#define CROS_USBPD_DATA_SIZE  16
#define CROS_USBPD_LOG_RESP_SIZE (sizeof(struct ec_response_pd_log) + \
      CROS_USBPD_DATA_SIZE)
#define CROS_USBPD_BUFFER_SIZE  (sizeof(struct cros_ec_command) + \
      CROS_USBPD_LOG_RESP_SIZE)
/* Buffer for building the PDLOG string */
#define BUF_SIZE 80

struct logger_data {
 struct device *dev;
 struct cros_ec_dev *ec_dev;
 u8 ec_buffer[CROS_USBPD_BUFFER_SIZE];
 struct delayed_work log_work;
 struct workqueue_struct *log_workqueue;
};

static const char * const chg_type_names[] = {
 "None", "PD", "Type-C", "Proprietary", "DCP", "CDP", "SDP",
 "Other", "VBUS"
};

static const char * const role_names[] = {
 "Disconnected", "SRC", "SNK", "SNK (not charging)"
};

static const char * const fault_names[] = {
 "---", "OCP", "fast OCP", "OVP", "Discharge"
};

__printf(3, 4)
static int append_str(char *buf, int pos, const char *fmt, ...)
{
 va_list args;
 int i;

 va_start(args, fmt);
 i = vsnprintf(buf + pos, BUF_SIZE - pos, fmt, args);
 va_end(args);

 return i;
}

static struct ec_response_pd_log *ec_get_log_entry(struct logger_data *logger)
{
 struct cros_ec_dev *ec_dev = logger->ec_dev;
 struct cros_ec_command *msg;
 int ret;

 msg = (struct cros_ec_command *)logger->ec_buffer;

 msg->command = ec_dev->cmd_offset + EC_CMD_PD_GET_LOG_ENTRY;
 msg->insize = CROS_USBPD_LOG_RESP_SIZE;

 ret = cros_ec_cmd_xfer_status(ec_dev->ec_dev, msg);
 if (ret < 0)
  return ERR_PTR(ret);

 return (struct ec_response_pd_log *)msg->data;
}

static void cros_usbpd_print_log_entry(struct ec_response_pd_log *r,
           ktime_t tstamp)
{
 const char *fault, *role, *chg_type;
 struct usb_chg_measures *meas;
 struct mcdp_info *minfo;
 int role_idx, type_idx;
 char buf[BUF_SIZE + 1];
 struct rtc_time rt;
 int len = 0;
 s32 rem;
 int i;

 /* The timestamp is the number of 1024th of seconds in the past */
 tstamp = ktime_sub_us(tstamp, r->timestamp << PD_LOG_TIMESTAMP_SHIFT);
 rt = rtc_ktime_to_tm(tstamp);

 switch (r->type) {
 case PD_EVENT_MCU_CHARGE:
  if (r->data & CHARGE_FLAGS_OVERRIDE)
   len += append_str(buf, len, "override ");

  if (r->data & CHARGE_FLAGS_DELAYED_OVERRIDE)
   len += append_str(buf, len, "pending_override ");

  role_idx = r->data & CHARGE_FLAGS_ROLE_MASK;
  role = role_idx < ARRAY_SIZE(role_names) ?
   role_names[role_idx] : "Unknown";

  type_idx = (r->data & CHARGE_FLAGS_TYPE_MASK)
    >> CHARGE_FLAGS_TYPE_SHIFT;

  chg_type = type_idx < ARRAY_SIZE(chg_type_names) ?
   chg_type_names[type_idx] : "???";

  if (role_idx == USB_PD_PORT_POWER_DISCONNECTED ||
      role_idx == USB_PD_PORT_POWER_SOURCE) {
   len += append_str(buf, len, "%s", role);
   break;
  }

  meas = (struct usb_chg_measures *)r->payload;
  len += append_str(buf, len, "%s %s %s %dmV max %dmV / %dmA",
      role, r->data & CHARGE_FLAGS_DUAL_ROLE ?
      "DRP" : "Charger",
      chg_type, meas->voltage_now,
      meas->voltage_max, meas->current_max);
  break;
 case PD_EVENT_ACC_RW_FAIL:
  len += append_str(buf, len, "RW signature check failed");
  break;
 case PD_EVENT_PS_FAULT:
  fault = r->data < ARRAY_SIZE(fault_names) ? fault_names[r->data]
         : "???";
  len += append_str(buf, len, "Power supply fault: %s", fault);
  break;
 case PD_EVENT_VIDEO_DP_MODE:
  len += append_str(buf, len, "DP mode %s",
      str_enabled_disabled(r->data == 1));
  break;
 case PD_EVENT_VIDEO_CODEC:
  minfo = (struct mcdp_info *)r->payload;
  len += append_str(buf, len, "HDMI info: family:%04x chipid:%04x ",
      MCDP_FAMILY(minfo->family),
      MCDP_CHIPID(minfo->chipid));
  len += append_str(buf, len, "irom:%d.%d.%d fw:%d.%d.%d",
      minfo->irom.major, minfo->irom.minor,
      minfo->irom.build, minfo->fw.major,
      minfo->fw.minor, minfo->fw.build);
  break;
 default:
  len += append_str(buf, len, "Event %02x (%04x) [", r->type,
      r->data);

  for (i = 0; i < PD_LOG_SIZE(r->size_port); i++)
   len += append_str(buf, len, "%02x ", r->payload[i]);

  len += append_str(buf, len, "]");
  break;
 }

 div_s64_rem(ktime_to_ms(tstamp), MSEC_PER_SEC, &rem);
 pr_info("PDLOG %d/%02d/%02d %02d:%02d:%02d.%03d P%d %s\n",
  rt.tm_year + 1900, rt.tm_mon + 1, rt.tm_mday,
  rt.tm_hour, rt.tm_min, rt.tm_sec, rem,
  PD_LOG_PORT(r->size_port), buf);
}

static void cros_usbpd_log_check(struct work_struct *work)
{
 struct logger_data *logger = container_of(to_delayed_work(work),
        struct logger_data,
        log_work);
 struct device *dev = logger->dev;
 struct ec_response_pd_log *r;
 int entries = 0;
 ktime_t now;

 while (entries++ < CROS_USBPD_MAX_LOG_ENTRIES) {
  r = ec_get_log_entry(logger);
  now = ktime_get_real();
  if (IS_ERR(r)) {
   dev_dbg(dev, "Cannot get PD log %ld\n", PTR_ERR(r));
   break;
  }
  if (r->type == PD_EVENT_NO_ENTRY)
   break;

  cros_usbpd_print_log_entry(r, now);
 }

 queue_delayed_work(logger->log_workqueue, &logger->log_work,
      CROS_USBPD_LOG_UPDATE_DELAY);
}

static int cros_usbpd_logger_probe(struct platform_device *pd)
{
 struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
 struct device *dev = &pd->dev;
 struct logger_data *logger;

 logger = devm_kzalloc(dev, sizeof(*logger), GFP_KERNEL);
 if (!logger)
  return -ENOMEM;

 logger->dev = dev;
 logger->ec_dev = ec_dev;

 platform_set_drvdata(pd, logger);

 /* Retrieve PD event logs periodically */
 INIT_DELAYED_WORK(&logger->log_work, cros_usbpd_log_check);
 logger->log_workqueue = create_singlethread_workqueue("cros_usbpd_log");
 if (!logger->log_workqueue)
  return -ENOMEM;

 queue_delayed_work(logger->log_workqueue, &logger->log_work,
      CROS_USBPD_LOG_UPDATE_DELAY);

 return 0;
}

static void cros_usbpd_logger_remove(struct platform_device *pd)
{
 struct logger_data *logger = platform_get_drvdata(pd);

 cancel_delayed_work_sync(&logger->log_work);
 destroy_workqueue(logger->log_workqueue);
}

static int __maybe_unused cros_usbpd_logger_resume(struct device *dev)
{
 struct logger_data *logger = dev_get_drvdata(dev);

 queue_delayed_work(logger->log_workqueue, &logger->log_work,
      CROS_USBPD_LOG_UPDATE_DELAY);

 return 0;
}

static int __maybe_unused cros_usbpd_logger_suspend(struct device *dev)
{
 struct logger_data *logger = dev_get_drvdata(dev);

 cancel_delayed_work_sync(&logger->log_work);

 return 0;
}

static SIMPLE_DEV_PM_OPS(cros_usbpd_logger_pm_ops, cros_usbpd_logger_suspend,
    cros_usbpd_logger_resume);

static const struct platform_device_id cros_usbpd_logger_id[] = {
 { DRV_NAME, 0 },
 {}
};
MODULE_DEVICE_TABLE(platform, cros_usbpd_logger_id);

static struct platform_driver cros_usbpd_logger_driver = {
 .driver = {
  .name = DRV_NAME,
  .pm = &cros_usbpd_logger_pm_ops,
 },
 .probe = cros_usbpd_logger_probe,
 .remove = cros_usbpd_logger_remove,
 .id_table = cros_usbpd_logger_id,
};

module_platform_driver(cros_usbpd_logger_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Logging driver for ChromeOS EC USBPD Charger.");