From 5a313f8705efcb1f4bd77bb20ecf49f6be1d2d7c Mon Sep 17 00:00:00 2001
From: xizx <xizx@motorola.com>
Date: Fri, 17 Apr 2020 20:28:56 +0800
Subject: [PATCH] qpnp-power-on-mmi: support hw_warmreset feature

When system is freezed or has no response, DFers often reset the phone
by long-press power btn. So there is no useful log for developpers and
the issue becomes very hard to analysis.

This hw_warmreset feature will trigger a warmreset reboot, so that next
cycle system can save the lastkmsg and re-trigger a clean hardware
cold reboot.

Only when the command line is configured with "hw_warmreset_enable=1",
the feature will take effect.

Change-Id: I9e0abcf3757b69175125bcf14188ad54f78a087d
Reviewed-on: https://gerrit.mot.com/1536790
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Zhenxin Xi <xizx@motorola.com>
Submit-Approved: Jira Key
---
 .../qpnp_power_on_mmi/qpnp-power-on-mmi.c     | 98 ++++++++++++++++++-
 1 file changed, 93 insertions(+), 5 deletions(-)

diff --git a/drivers/input/misc/qpnp_power_on_mmi/qpnp-power-on-mmi.c b/drivers/input/misc/qpnp_power_on_mmi/qpnp-power-on-mmi.c
index 4e2b152296b5..07639fd4c070 100644
--- a/drivers/input/misc/qpnp_power_on_mmi/qpnp-power-on-mmi.c
+++ b/drivers/input/misc/qpnp_power_on_mmi/qpnp-power-on-mmi.c
@@ -40,8 +40,28 @@ struct qpnp_pon_mmi {
 	struct platform_device	*pdev;
 	struct delayed_work	kpd_bark_work;
 	u32 			kpd_bark_irq;
+	u32 			kpd_hw_warmreset;
 };
 
+static bool is_hw_warmreset_enabled()
+{
+	struct device_node *np = of_find_node_by_path("/chosen");
+	bool value = false;
+	const char *bootargs = NULL;
+
+	if (!np)
+		return false;
+
+	if ((!of_property_read_string(np, "bootargs", &bootargs))
+		&& (strstr(bootargs, "hw_warmreset_enable=1"))) {
+		value = true;
+	}
+
+	of_node_put(np);
+
+	return value;
+}
+
 static bool mmi_kungpow_check(void)
 {
 	struct device_node *soc = of_find_node_by_path("/soc");
@@ -58,16 +78,79 @@ static bool mmi_kungpow_check(void)
 	return has_kungpow;
 }
 
+static unsigned int get_boot_seq(void)
+{
+	unsigned int boot_seq = 0;
+	struct device_node *n = of_find_node_by_path("/chosen");
+
+	if (n == NULL)
+		return 0;
+
+	of_property_read_u32(n, "mmi,boot_seq", &boot_seq);
+	of_node_put(n);
+
+	return boot_seq;
+}
+
+static int print_blocked_tasks()
+{
+	mm_segment_t fs;
+	char cmd;
+	size_t written;
+	loff_t pos = 0;
+	struct file *filep;
+	int rc = 0;
+
+	fs = get_fs();
+	set_fs(KERNEL_DS);
+
+	filep = filp_open("/proc/sysrq-trigger", O_WRONLY, 0200);
+	if (IS_ERR_OR_NULL(filep)) {
+		rc = PTR_ERR(filep);
+		pr_err("opening sysrq errno=%d\n", rc);
+		set_fs(fs);
+		return rc;
+	}
+
+	pr_info("set default console loglevel\n");
+	cmd = '7';
+	written = vfs_write(filep, &cmd, 1, &pos);
+	if (written < 1) {
+		pr_err("failed to write sysrq\n");
+		rc = -EIO;
+	}
+
+	pr_info("start to print block task\n");
+	cmd = 'w';
+	written = vfs_write(filep, &cmd, 1, &pos);
+	if (written < 1) {
+		pr_err("failed to write sysrq\n");
+		rc = -EIO;
+	}
+
+	set_fs(fs);
+	filp_close(filep, NULL);
+
+	return rc;
+}
+
 static void kpd_bark_work_func(struct work_struct *work)
 {
 	struct qpnp_pon_mmi *pon =
 		container_of(work, struct qpnp_pon_mmi, kpd_bark_work.work);
 
-	dev_err(&pon->pdev->dev, "HW User Reset! 2 sec to Reset!\n");
-	qpnp_pon_store_extra_reset_info(RESET_EXTRA_RESET_KUNPOW_REASON,
-		mmi_kungpow_check() ? 0 : RESET_EXTRA_RESET_KUNPOW_REASON);
-	qpnp_pon_system_pwr_off(PON_POWER_OFF_HARD_RESET);
-	kernel_halt();
+	if (pon->kpd_hw_warmreset) {
+		pr_err("trigger hw_warmreset, BOOT_SEQ=%d\n", get_boot_seq());
+		/* print blocked tasks */
+		print_blocked_tasks();
+		kernel_restart("hw_warmreset");
+	} else {
+		dev_err(&pon->pdev->dev, "HW User Reset! 2 sec to Reset!\n");
+		qpnp_pon_store_extra_reset_info(RESET_EXTRA_RESET_KUNPOW_REASON,
+			mmi_kungpow_check() ? 0 : RESET_EXTRA_RESET_KUNPOW_REASON);
+		qpnp_pon_system_pwr_off(PON_POWER_OFF_HARD_RESET);
+		kernel_halt();
+	}
 }
 
 static irqreturn_t qpnp_kpdpwr_bark_irq(int irq, void *_pon)
@@ -114,6 +197,11 @@ static int qpnp_pon_mmi_probe(struct platform_device *pdev)
 		return rc;
 	}
 
+	if (is_hw_warmreset_enabled()) {
+		pon->kpd_hw_warmreset = 1;
+		pr_info("hw_warmreset feature is enabled\n");
+	}
+
 	return 0;
 }