[PATCH] regulator: twl: Enable regulators over the powerbus as well

Ivaylo Dimitrov
2016-03-23T19:24:18Z

Assigning a device group to a regulator does not change its state. To
change the state of a regulator a message over the powerbus is required.
Also, the check for the current state of a regulator should not count on
a device group being assigned, but on the current resource state.

Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
---
drivers/regulator/twl-regulator.c | 85 ++++++++++++++++++++++++++++++++++-----
1 file changed, 75 insertions(+), 10 deletions(-)

diff --git a/drivers/regulator/twl-regulator.c b/drivers/regulator/twl-regulator.c
index 955a6fb..125d5b1 100644
--- a/drivers/regulator/twl-regulator.c
+++ b/drivers/regulator/twl-regulator.c
@@ -21,7 +21,7 @@
#include <linux/regulator/machine.h>
#include <linux/regulator/of_regulator.h>
#include <linux/i2c/twl.h>
-
+#include <linux/delay.h>

/*
* The TWL4030/TW5030/TPS659x0/TWL6030 family chips include power management, a
@@ -165,7 +165,7 @@ static int twl4030reg_is_enabled(struct regulator_dev *rdev)
if (state < 0)
return state;

- return state & P1_GRP_4030;
+ return (state & 0x0f) != 0;
}

static int twl6030reg_is_enabled(struct regulator_dev *rdev)
@@ -188,11 +188,78 @@ static int twl6030reg_is_enabled(struct regulator_dev *rdev)
return grp && (val == TWL6030_CFG_STATE_ON);
}

+#define PB_I2C_BUSY BIT(0)
+#define PB_I2C_BWEN BIT(1)
+
+static int twl4030_wait_pb_ready(void)
+{
+
+ int ret;
+ int timeout = 10;
+ u8 val;
+
+ do {
+ ret = twl_i2c_read_u8(TWL_MODULE_PM_MASTER, &val,
+ TWL4030_PM_MASTER_PB_CFG);
+ if (ret < 0)
+ return ret;
+
+ if (!(val & PB_I2C_BUSY))
+ return 0;
+
+ mdelay(1);
+ timeout--;
+ } while (timeout);
+
+ return -ETIMEDOUT;
+}
+
+static int twl4030_send_pb_msg(unsigned msg)
+{
+ u8 val;
+ int ret;
+
+ /* save powerbus configuration */
+ ret = twl_i2c_read_u8(TWL_MODULE_PM_MASTER, &val,
+ TWL4030_PM_MASTER_PB_CFG);
+ if (ret < 0)
+ return ret;
+
+ /* Enable I2C access to powerbus */
+ ret = twl_i2c_write_u8(TWL_MODULE_PM_MASTER, val | PB_I2C_BWEN,
+ TWL4030_PM_MASTER_PB_CFG);
+ if (ret < 0)
+ return ret;
+
+ ret = twl4030_wait_pb_ready();
+ if (ret < 0)
+ return ret;
+
+ ret = twl_i2c_write_u8(TWL_MODULE_PM_MASTER, msg >> 8,
+ TWL4030_PM_MASTER_PB_WORD_MSB);
+ if (ret < 0)
+ return ret;
+
+ ret = twl_i2c_write_u8(TWL_MODULE_PM_MASTER, msg & 0xff,
+ TWL4030_PM_MASTER_PB_WORD_LSB);
+ if (ret < 0)
+ return ret;
+
+ ret = twl4030_wait_pb_ready();
+ if (ret < 0)
+ return ret;
+
+ /* Restore powerbus configuration */
+ return twl_i2c_write_u8(TWL_MODULE_PM_MASTER, val,
+ TWL_MODULE_PM_MASTER);
+}
+
static int twl4030reg_enable(struct regulator_dev *rdev)
{
struct twlreg_info *info = rdev_get_drvdata(rdev);
int grp;
int ret;
+ unsigned message;

grp = twlreg_grp(rdev);
if (grp < 0)
@@ -201,8 +268,12 @@ static int twl4030reg_enable(struct regulator_dev *rdev)
grp |= P1_GRP_4030;

ret = twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_GRP, grp);
+ if (ret < 0)
+ return ret;

- return ret;
+ message = MSG_SINGULAR(DEV_GRP_P1, info->id, RES_STATE_ACTIVE);
+
+ return twl4030_send_pb_msg(message);
}

static int twl6030reg_enable(struct regulator_dev *rdev)
@@ -324,13 +395,7 @@ static int twl4030reg_set_mode(struct regulator_dev *rdev, unsigned mode)
if (!(status & (P3_GRP_4030 | P2_GRP_4030 | P1_GRP_4030)))
return -EACCES;

- status = twl_i2c_write_u8(TWL_MODULE_PM_MASTER,
- message >> 8, TWL4030_PM_MASTER_PB_WORD_MSB);
- if (status < 0)
- return status;
-
- return twl_i2c_write_u8(TWL_MODULE_PM_MASTER,
- message & 0xff, TWL4030_PM_MASTER_PB_WORD_LSB);
+ return twl4030_send_pb_msg(message);
}

static int twl6030reg_set_mode(struct regulator_dev *rdev, unsigned mode)
--
1.9.1