[PATCH v6 5/6] regulator: pfuze100-regulator: provide pm_power_off_prepare handler

From: Oleksij Rempel
Date: Fri Oct 27 2017 - 05:50:43 EST


On some boards the SoC can use one pin "PMIC_STBY_REQ" to notify th PMIC
about state changes. In this case internal state of PMIC must be
preconfigured for upcomming state change.
It works fine with the current regulator framework, except with the
power-off case.

This patch is providing an optional pm_power_off_prepare 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
suspend to ram: 40 mA

Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
---
drivers/regulator/pfuze100-regulator.c | 92 ++++++++++++++++++++++++++++++++++
1 file changed, 92 insertions(+)

diff --git a/drivers/regulator/pfuze100-regulator.c b/drivers/regulator/pfuze100-regulator.c
index 63922a2167e5..f6c276ed91d8 100644
--- a/drivers/regulator/pfuze100-regulator.c
+++ b/drivers/regulator/pfuze100-regulator.c
@@ -28,6 +28,7 @@
#include <linux/regulator/pfuze100.h>
#include <linux/i2c.h>
#include <linux/slab.h>
+#include <linux/kallsyms.h>
#include <linux/regmap.h>

#define PFUZE_NUMREGS 128
@@ -42,11 +43,17 @@

#define PFUZE100_COINVOL 0x1a
#define PFUZE100_SW1ABVOL 0x20
+#define PFUZE100_SW1ABMODE 0x23
#define PFUZE100_SW1CVOL 0x2e
+#define PFUZE100_SW1CMODE 0x31
#define PFUZE100_SW2VOL 0x35
+#define PFUZE100_SW2MODE 0x38
#define PFUZE100_SW3AVOL 0x3c
+#define PFUZE100_SW3AMODE 0x3f
#define PFUZE100_SW3BVOL 0x43
+#define PFUZE100_SW3BMODE 0x46
#define PFUZE100_SW4VOL 0x4a
+#define PFUZE100_SW4MODE 0x4d
#define PFUZE100_SWBSTCON1 0x66
#define PFUZE100_VREFDDRCON 0x6a
#define PFUZE100_VSNVSVOL 0x6b
@@ -57,6 +64,13 @@
#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)
+
enum chips { PFUZE100, PFUZE200, PFUZE3000 = 3 };

struct pfuze_regulator {
@@ -489,6 +503,69 @@ static inline struct device_node *match_of_node(int index)
}
#endif

+static struct pfuze_chip *syspm_pfuze_chip;
+
+static void pfuze_power_off_prepare(void)
+{
+ dev_info(syspm_pfuze_chip->dev, "Configure standy mode for power off");
+
+ /* Switch from default mode: APS/APS to APS/Off */
+ regmap_update_bits(syspm_pfuze_chip->regmap, PFUZE100_SW1ABMODE,
+ PFUZE100_SWxMODE_MASK, PFUZE100_SWxMODE_APS_OFF);
+ regmap_update_bits(syspm_pfuze_chip->regmap, PFUZE100_SW1CMODE,
+ PFUZE100_SWxMODE_MASK, PFUZE100_SWxMODE_APS_OFF);
+ regmap_update_bits(syspm_pfuze_chip->regmap, PFUZE100_SW2MODE,
+ PFUZE100_SWxMODE_MASK, PFUZE100_SWxMODE_APS_OFF);
+ regmap_update_bits(syspm_pfuze_chip->regmap, PFUZE100_SW3AMODE,
+ PFUZE100_SWxMODE_MASK, PFUZE100_SWxMODE_APS_OFF);
+ regmap_update_bits(syspm_pfuze_chip->regmap, PFUZE100_SW3BMODE,
+ PFUZE100_SWxMODE_MASK, PFUZE100_SWxMODE_APS_OFF);
+ regmap_update_bits(syspm_pfuze_chip->regmap, PFUZE100_SW4MODE,
+ PFUZE100_SWxMODE_MASK, PFUZE100_SWxMODE_APS_OFF);
+
+ regmap_update_bits(syspm_pfuze_chip->regmap, PFUZE100_VGEN1VOL,
+ PFUZE100_VGENxLPWR | PFUZE100_VGENxSTBY,
+ PFUZE100_VGENxSTBY);
+ regmap_update_bits(syspm_pfuze_chip->regmap, PFUZE100_VGEN2VOL,
+ PFUZE100_VGENxLPWR | PFUZE100_VGENxSTBY,
+ PFUZE100_VGENxSTBY);
+ regmap_update_bits(syspm_pfuze_chip->regmap, PFUZE100_VGEN3VOL,
+ PFUZE100_VGENxLPWR | PFUZE100_VGENxSTBY,
+ PFUZE100_VGENxSTBY);
+ regmap_update_bits(syspm_pfuze_chip->regmap, PFUZE100_VGEN4VOL,
+ PFUZE100_VGENxLPWR | PFUZE100_VGENxSTBY,
+ PFUZE100_VGENxSTBY);
+ regmap_update_bits(syspm_pfuze_chip->regmap, PFUZE100_VGEN5VOL,
+ PFUZE100_VGENxLPWR | PFUZE100_VGENxSTBY,
+ PFUZE100_VGENxSTBY);
+ regmap_update_bits(syspm_pfuze_chip->regmap, PFUZE100_VGEN6VOL,
+ PFUZE100_VGENxLPWR | PFUZE100_VGENxSTBY,
+ PFUZE100_VGENxSTBY);
+}
+
+static int pfuze_power_off_prepare_init(struct pfuze_chip *pfuze_chip)
+{
+ if (pfuze_chip->chip_id != PFUZE100) {
+ dev_warn(pfuze_chip->dev, "Requested pm_power_off_prepare handler for not supported chip\n");
+ return -ENODEV;
+ }
+
+ if (pm_power_off_prepare) {
+ dev_warn(pfuze_chip->dev, "pm_power_off_prepare is already registered.\n");
+ return -EBUSY;
+ }
+
+ if (syspm_pfuze_chip) {
+ dev_warn(pfuze_chip->dev, "syspm_pfuze_chip is already set.\n");
+ return -EBUSY;
+ }
+
+ syspm_pfuze_chip = pfuze_chip;
+ pm_power_off_prepare = pfuze_power_off_prepare;
+
+ return 0;
+}
+
static int pfuze_identify(struct pfuze_chip *pfuze_chip)
{
unsigned int value;
@@ -659,6 +736,20 @@ static int pfuze100_regulator_probe(struct i2c_client *client,
}
}

+ if (of_property_read_bool(client->dev.of_node,
+ "fsl,pmic-stby-poweroff"))
+ return pfuze_power_off_prepare_init(pfuze_chip);
+
+ return 0;
+}
+
+static int pfuze100_regulator_remove(struct i2c_client *client)
+{
+ if (syspm_pfuze_chip) {
+ syspm_pfuze_chip = NULL;
+ pm_power_off_prepare = NULL;
+ }
+
return 0;
}

@@ -669,6 +760,7 @@ static struct i2c_driver pfuze_driver = {
.of_match_table = pfuze_dt_ids,
},
.probe = pfuze100_regulator_probe,
+ .remove = pfuze100_regulator_remove,
};
module_i2c_driver(pfuze_driver);

--
2.11.0