regulator: pfuze: provide power over standby handler

This patch is providing an optional power off handler
which will configure standby state of the PMIC to disable all power lines.

In my power consumption test on RIoTBoard, I got the following results:
power off without this patch:   320 mA
power off with this patch:      2   mA

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

2 files changed, 68 insertions, 0 deletions

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 6a6c6d2248..92db8dc0e0 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -19,5 +19,6 @@ config REGULATOR_BCM283X
 config REGULATOR_PFUZE
 	bool "Freescale PFUZE100/200/3000 regulator driver"
 	depends on I2C
+	depends on ARCH_IMX6
 
 endif
diff --git a/drivers/regulator/pfuze.c b/drivers/regulator/pfuze.c
index 2a5fb715ce..dc41e8f55b 100644
--- a/drivers/regulator/pfuze.c
+++ b/drivers/regulator/pfuze.c
@@ -26,10 +26,33 @@
 
 #include <i2c/i2c.h>
 
+#include <poweroff.h>
+#include <mach/imx6.h>
+
 #define DRIVERNAME		"pfuze"
 
 #define MC13XXX_NUMREGS		0x3f
 
+#define PFUZE100_SW1ABMODE	0x23
+#define PFUZE100_SW1CMODE	0x31
+#define PFUZE100_SW2MODE	0x38
+#define PFUZE100_SW3AMODE	0x3f
+#define PFUZE100_SW3BMODE	0x46
+#define PFUZE100_SW4MODE	0x4d
+#define PFUZE100_VGEN1VOL	0x6c
+#define PFUZE100_VGEN2VOL	0x6d
+#define PFUZE100_VGEN3VOL	0x6e
+#define PFUZE100_VGEN4VOL	0x6f
+#define PFUZE100_VGEN5VOL	0x70
+#define PFUZE100_VGEN6VOL	0x71
+
+#define PFUZE100_SWxMODE_MASK	0xf
+#define PFUZE100_SWxMODE_APS_APS	0x8
+#define PFUZE100_SWxMODE_APS_OFF	0x4
+
+#define PFUZE100_VGENxLPWR	BIT(6)
+#define PFUZE100_VGENxSTBY	BIT(5)
+
 struct pfuze {
 	struct device_d			*dev;
 	struct regmap			*map;
@@ -85,6 +108,46 @@ static int pfuze_i2c_reg_write(void *ctx, unsigned int reg, unsigned int val)
 	return ret == 1 ? 0 : ret;
 }
 
+static void pfuze_power_off_prepare(struct poweroff_handler *handler)
+{
+	dev_info(pfuze_dev->dev, "Configure standy mode for power off");
+
+	/* Switch from default mode: APS/APS to APS/Off */
+	regmap_write_bits(pfuze_dev->map, PFUZE100_SW1ABMODE,
+			  PFUZE100_SWxMODE_MASK, PFUZE100_SWxMODE_APS_OFF);
+	regmap_write_bits(pfuze_dev->map, PFUZE100_SW1CMODE,
+			  PFUZE100_SWxMODE_MASK, PFUZE100_SWxMODE_APS_OFF);
+	regmap_write_bits(pfuze_dev->map, PFUZE100_SW2MODE,
+			  PFUZE100_SWxMODE_MASK, PFUZE100_SWxMODE_APS_OFF);
+	regmap_write_bits(pfuze_dev->map, PFUZE100_SW3AMODE,
+			  PFUZE100_SWxMODE_MASK, PFUZE100_SWxMODE_APS_OFF);
+	regmap_write_bits(pfuze_dev->map, PFUZE100_SW3BMODE,
+			  PFUZE100_SWxMODE_MASK, PFUZE100_SWxMODE_APS_OFF);
+	regmap_write_bits(pfuze_dev->map, PFUZE100_SW4MODE,
+			  PFUZE100_SWxMODE_MASK, PFUZE100_SWxMODE_APS_OFF);
+
+	regmap_write_bits(pfuze_dev->map, PFUZE100_VGEN1VOL,
+			  PFUZE100_VGENxLPWR | PFUZE100_VGENxSTBY,
+			  PFUZE100_VGENxSTBY);
+	regmap_write_bits(pfuze_dev->map, PFUZE100_VGEN2VOL,
+			  PFUZE100_VGENxLPWR | PFUZE100_VGENxSTBY,
+			  PFUZE100_VGENxSTBY);
+	regmap_write_bits(pfuze_dev->map, PFUZE100_VGEN3VOL,
+			  PFUZE100_VGENxLPWR | PFUZE100_VGENxSTBY,
+			  PFUZE100_VGENxSTBY);
+	regmap_write_bits(pfuze_dev->map, PFUZE100_VGEN4VOL,
+			  PFUZE100_VGENxLPWR | PFUZE100_VGENxSTBY,
+			  PFUZE100_VGENxSTBY);
+	regmap_write_bits(pfuze_dev->map, PFUZE100_VGEN5VOL,
+			  PFUZE100_VGENxLPWR | PFUZE100_VGENxSTBY,
+			  PFUZE100_VGENxSTBY);
+	regmap_write_bits(pfuze_dev->map, PFUZE100_VGEN6VOL,
+			  PFUZE100_VGENxLPWR | PFUZE100_VGENxSTBY,
+			  PFUZE100_VGENxSTBY);
+
+	imx6_pm_stby_poweroff();
+}
+
 static struct regmap_bus regmap_pfuze_i2c_bus = {
 	.reg_write = pfuze_i2c_reg_write,
 	.reg_read = pfuze_i2c_reg_read,
@@ -122,6 +185,10 @@ static int __init pfuze_probe(struct device_d *dev)
 	if (pfuze_init_callback)
 		pfuze_init_callback(pfuze_dev->map);
 
+	if (of_property_read_bool(dev->device_node,
+				  "fsl,pmic-stby-poweroff"))
+		return poweroff_handler_register_fn(pfuze_power_off_prepare);
+
 	return 0;
 }