linux-kernel - [PATCH V2 2/2] power: twl4030_charger: attempt to power off in case of critical events

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Date:	Wed, 28 May 2014 16:46:50 -0500
From:	Nishanth Menon <nm@...com>
To:	<dbaryshkov@...il.com>, <tony@...mide.com>
CC:	<balbi@...com>, <linux@....linux.org.uk>, <dwmw2@...radead.org>,
	<linux-arm-kernel@...ts.infradead.org>,
	<linux-kernel@...r.kernel.org>, <linux-omap@...r.kernel.org>,
	Nishanth Menon <nm@...com>
Subject: [PATCH V2 2/2] power: twl4030_charger: attempt to power off in case of critical events

Attempt to power off in case of critical events such as battery removal,
over voltage events.

There is no guarentee that we'd be in a safe scenario here, but the very
least we can try to do is to power off the device to prevent damage to
the system instead of just printing a message and hoping for the best.

NOTE: twl4030 should attempt some form of recovery, but just depending
on that is never a safe alternative.

Signed-off-by: Nishanth Menon <nm@...com>
---
new patch. original attempt was: https://patchwork.kernel.org/patch/4002371/

NOTE: we dont have poweroff support yet enabled on LDP, but it just needs
relevant dts entry.

 drivers/power/twl4030_charger.c |   26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/drivers/power/twl4030_charger.c b/drivers/power/twl4030_charger.c
index 2598c58..ed0dbd2 100644
--- a/drivers/power/twl4030_charger.c
+++ b/drivers/power/twl4030_charger.c
@@ -22,6 +22,7 @@
 #include <linux/power_supply.h>
 #include <linux/notifier.h>
 #include <linux/usb/otg.h>
+#include <linux/reboot.h>
 #include <linux/regulator/machine.h>
 
 #define TWL4030_BCIMSTATEC	0x02
@@ -332,6 +333,7 @@ static irqreturn_t twl4030_bci_interrupt(int irq, void *arg)
 	struct twl4030_bci *bci = arg;
 	u8 irqs1, irqs2;
 	int ret;
+	bool power_off = false;
 
 	ret = twl_i2c_read_u8(TWL4030_MODULE_INTERRUPTS, &irqs1,
 			      TWL4030_INTERRUPTS_BCIISR1A);
@@ -352,20 +354,34 @@ static irqreturn_t twl4030_bci_interrupt(int irq, void *arg)
 	}
 
 	/* various monitoring events, for now we just log them here */
-	if (irqs1 & (TWL4030_TBATOR2 | TWL4030_TBATOR1))
+	if (irqs1 & (TWL4030_TBATOR2 | TWL4030_TBATOR1)) {
 		dev_warn(bci->dev, "battery temperature out of range\n");
+		power_off = true;
+	}
 
-	if (irqs1 & TWL4030_BATSTS)
+	if (irqs1 & TWL4030_BATSTS) {
 		dev_crit(bci->dev, "battery disconnected\n");
+		power_off = true;
+	}
 
-	if (irqs2 & TWL4030_VBATOV)
+	if (irqs2 & TWL4030_VBATOV) {
 		dev_crit(bci->dev, "VBAT overvoltage\n");
+		power_off = true;
+	}
 
-	if (irqs2 & TWL4030_VBUSOV)
+	if (irqs2 & TWL4030_VBUSOV) {
 		dev_crit(bci->dev, "VBUS overvoltage\n");
+		power_off = true;
+	}
 
-	if (irqs2 & TWL4030_ACCHGOV)
+	if (irqs2 & TWL4030_ACCHGOV) {
 		dev_crit(bci->dev, "Ac charger overvoltage\n");
+		power_off = true;
+	}
+
+	/* Try to shutdown the system */
+	if (power_off)
+		orderly_poweroff(true);
 
 	return IRQ_HANDLED;
 }
-- 
1.7.9.5

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