linux-kernel - [PATCH] platform/chrome: mfd/cros_ec_sysfs: Add sysfs entry to retrieve EC uptime.

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Message-Id: <20190315170413.108114-2-twawrzynczak@chromium.org>
Date:   Fri, 15 Mar 2019 11:04:13 -0600
From:   Tim Wawrzynczak <twawrzynczak@...omium.org>
To:     bleung@...omium.org
Cc:     olof@...om.net, lee.jones@...aro.org, linux-kernel@...r.kernel.org,
        Tim Wawrzynczak <twawrzynczak@...omium.org>
Subject: [PATCH] platform/chrome: mfd/cros_ec_sysfs: Add sysfs entry to retrieve EC uptime.

Adds a new sysfs node under the cros_ec device which contains the uptime
of the EC in milliseconds since boot.

Signed-off-by: Tim Wawrzynczak <twawrzynczak@...omium.org>
---
 drivers/platform/chrome/cros_ec_sysfs.c | 34 +++++++++++++++++++++++++
 include/linux/mfd/cros_ec_commands.h    | 15 +++++++++++
 2 files changed, 49 insertions(+)

diff --git a/drivers/platform/chrome/cros_ec_sysfs.c b/drivers/platform/chrome/cros_ec_sysfs.c
index 5a6db3fe213a..7e5ca1e2900b 100644
--- a/drivers/platform/chrome/cros_ec_sysfs.c
+++ b/drivers/platform/chrome/cros_ec_sysfs.c
@@ -123,6 +123,38 @@ static ssize_t reboot_store(struct device *dev,
 	return count;
 }
 
+static ssize_t uptime_show(struct device *dev,
+			   struct device_attribute *attr, char *buf)
+{
+	struct ec_response_uptime_info *resp;
+	struct cros_ec_command *msg;
+	int ret;
+	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
+	u32 time_since_ec_boot_ms;
+
+	msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	/* Get EC uptime information */
+	msg->version = 0;
+	msg->command = EC_CMD_GET_UPTIME_INFO + ec->cmd_offset;
+	msg->insize = sizeof(*resp);
+	msg->outsize = 0;
+	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
+	if (ret < 0) {
+		time_since_ec_boot_ms = 0;
+	} else {
+		resp = (struct ec_response_uptime_info *)msg->data;
+		time_since_ec_boot_ms = resp->time_since_ec_boot_ms;
+	}
+
+	ret = scnprintf(buf, PAGE_SIZE, "%u\n", time_since_ec_boot_ms);
+
+	kfree(msg);
+	return ret;
+}
+
 static ssize_t version_show(struct device *dev,
 			    struct device_attribute *attr, char *buf)
 {
@@ -330,12 +362,14 @@ static DEVICE_ATTR_RW(reboot);
 static DEVICE_ATTR_RO(version);
 static DEVICE_ATTR_RO(flashinfo);
 static DEVICE_ATTR_RW(kb_wake_angle);
+static DEVICE_ATTR_RO(uptime);
 
 static struct attribute *__ec_attrs[] = {
 	&dev_attr_kb_wake_angle.attr,
 	&dev_attr_reboot.attr,
 	&dev_attr_version.attr,
 	&dev_attr_flashinfo.attr,
+	&dev_attr_uptime.attr,
 	NULL,
 };
 
diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h
index a8c882b5c222..38e7e6dcca97 100644
--- a/include/linux/mfd/cros_ec_commands.h
+++ b/include/linux/mfd/cros_ec_commands.h
@@ -4697,6 +4697,21 @@ struct __ec_align4 ec_params_rwsig_action {
 	uint32_t action;
 };
 
+/* For getting EC uptime & AP reset information */
+#define EC_CMD_GET_UPTIME_INFO	0x0121
+
+struct __ec_align4 ec_response_uptime_info {
+	uint32_t time_since_ec_boot_ms;   /* uptime in ms */
+	uint32_t ap_resets_since_ec_boot; /* AP resets recorded by EC */
+	uint32_t ec_reset_flags;          /* RESET_* flags */
+	/* Empty log entries have cause and timestamp set to zero */
+	struct ap_reset_log_entry {
+		uint16_t reset_cause;     /* enum chipset_*_reason */
+		uint16_t reserved;        /* reserved for protocol growth */
+		uint32_t reset_time_ms;   /* time of reset assertion */
+	} recent_ap_reset[4];
+};
+
 /*****************************************************************************/
 /* The command range 0x200-0x2FF is reserved for Rotor. */
 
-- 
2.20.1