[U-Boot] [PATCH v3 1/3] arm: odroid: pmic77686: allow buck voltage settings

[Suriyan Ramasami]

Allow to set the buck voltage for the max77686.
This will be used to reset the SMC LAN9730 ethernet on the odroids.

Signed-off-by: Suriyan Ramasami <suriyan.r at gmail.com>

---

Changes in v3:
* Correct ldo and buck validation logic
* Jaehoon/Przemyslaw - Use negative errno values for error condistions
* Albert - its buck not bucket

Changes in v2:
* Jaehoon - separate out this patch

Changes in v1:
- First try

 drivers/power/pmic/pmic_max77686.c | 52 +++++++++++++++++++++++++++++++++++---
 include/power/max77686_pmic.h      |  3 +++
 2 files changed, 52 insertions(+), 3 deletions(-)

diff --git a/drivers/power/pmic/pmic_max77686.c b/drivers/power/pmic/pmic_max77686.c
index df1fd91..95b1a57 100644
--- a/drivers/power/pmic/pmic_max77686.c
+++ b/drivers/power/pmic/pmic_max77686.c
@@ -42,11 +42,30 @@ static unsigned int max77686_ldo_volt2hex(int ldo, ulong uV)
 	return 0;
 }
 
+static int max77686_buck_volt2hex(int buck, ulong uV)
+{
+	int hex = 0;
+
+	if (buck < 5 || buck > 9) {
+		debug("%s: buck %d is not supported\n", __func__, buck);
+		return -EINVAL;
+	}
+
+	hex = (uV - 750000) / 50000;
+
+	if (hex >= 0 && hex <= MAX77686_BUCK_VOLT_MAX_HEX)
+		return hex;
+
+	debug("%s: %ld is wrong voltage value for BUCK%d\n",
+	      __func__, uV, buck);
+	return -EINVAL;
+}
+
 int max77686_set_ldo_voltage(struct pmic *p, int ldo, ulong uV)
 {
 	unsigned int val, ret, hex, adr;
 
-	if (ldo < 1 && ldo > 26) {
+	if (ldo < 1 || ldo > 26) {
 		printf("%s: %d is wrong ldo number\n", __func__, ldo);
 		return -1;
 	}
@@ -68,11 +87,38 @@ int max77686_set_ldo_voltage(struct pmic *p, int ldo, ulong uV)
 	return ret;
 }
 
+int max77686_set_buck_voltage(struct pmic *p, int buck, ulong uV)
+{
+	unsigned int val, adr;
+	int hex, ret;
+
+	if (buck < 5 || buck > 9) {
+		printf("%s: %d is an unsupported bucket number\n",
+		       __func__, buck);
+		return -EINVAL;
+	}
+
+	adr = max77686_buck_addr[buck] + 1;
+	hex = max77686_buck_volt2hex(buck, uV);
+
+	if (hex < 0)
+		return hex;
+
+	ret = pmic_reg_read(p, adr, &val);
+	if (ret)
+		return ret;
+
+	val &= ~MAX77686_BUCK_VOLT_MASK;
+	ret |= pmic_reg_write(p, adr, val | hex);
+
+	return ret;
+}
+
 int max77686_set_ldo_mode(struct pmic *p, int ldo, char opmode)
 {
 	unsigned int val, ret, adr, mode;
 
-	if (ldo < 1 && 26 < ldo) {
+	if (ldo < 1 || 26 < ldo) {
 		printf("%s: %d is wrong ldo number\n", __func__, ldo);
 		return -1;
 	}
@@ -157,7 +203,7 @@ int max77686_set_buck_mode(struct pmic *p, int buck, char opmode)
 	/* mode */
 	switch (opmode) {
 	case OPMODE_OFF:
-		mode = MAX77686_BUCK_MODE_OFF;
+		mode = MAX77686_BUCK_MODE_OFF << mode_shift;
 		break;
 	case OPMODE_STANDBY:
 		switch (buck) {
diff --git a/include/power/max77686_pmic.h b/include/power/max77686_pmic.h
index c2a772a..b0e4255 100644
--- a/include/power/max77686_pmic.h
+++ b/include/power/max77686_pmic.h
@@ -150,6 +150,7 @@ enum {
 
 int max77686_set_ldo_voltage(struct pmic *p, int ldo, ulong uV);
 int max77686_set_ldo_mode(struct pmic *p, int ldo, char opmode);
+int max77686_set_buck_voltage(struct pmic *p, int buck, ulong uV);
 int max77686_set_buck_mode(struct pmic *p, int buck, char opmode);
 
 #define MAX77686_LDO_VOLT_MAX_HEX	0x3f
@@ -159,6 +160,8 @@ int max77686_set_buck_mode(struct pmic *p, int buck, char opmode);
 #define MAX77686_LDO_MODE_STANDBY	(0x01 << 0x06)
 #define MAX77686_LDO_MODE_LPM		(0x02 << 0x06)
 #define MAX77686_LDO_MODE_ON		(0x03 << 0x06)
+#define MAX77686_BUCK_VOLT_MAX_HEX	0x3f
+#define MAX77686_BUCK_VOLT_MASK		0x3f
 #define MAX77686_BUCK_MODE_MASK		0x03
 #define MAX77686_BUCK_MODE_SHIFT_1	0x00
 #define MAX77686_BUCK_MODE_SHIFT_2	0x04
-- 
1.9.1