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board: common: vid: Add support for LTC3882 voltage regulator chip

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Restructures common driver to support LTC3882 voltage regulator
chip.

Signed-off-by: Ashish Kumar <Ashish.Kumar@nxp.com>
Signed-off-by: Rajesh Bhagat <rajesh.bhagat@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>
This commit is contained in:
Rajesh Bhagat
2018-01-17 16:13:05 +05:30
committed by York Sun
parent 6f2d0a5020
commit 23a12cb3d0
4 changed files with 115 additions and 2 deletions
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77
board/freescale/common/vid.c
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@@ -174,6 +174,36 @@ static int read_voltage_from_IR(int i2caddress)
}
#endif
#ifdef CONFIG_VOL_MONITOR_LTC3882_READ
/* read the current value of the LTC Regulator Voltage */
static int read_voltage_from_LTC(int i2caddress)
{
int ret, vcode = 0;
u8 chan = PWM_CHANNEL0;
/* select the PAGE 0 using PMBus commands PAGE for VDD*/
ret = i2c_write(I2C_VOL_MONITOR_ADDR,
PMBUS_CMD_PAGE, 1, &chan, 1);
if (ret) {
printf("VID: failed to select VDD Page 0\n");
return ret;
}
/*read the output voltage using PMBus command READ_VOUT*/
ret = i2c_read(I2C_VOL_MONITOR_ADDR,
PMBUS_CMD_READ_VOUT, 1, (void *)&vcode, 2);
if (ret) {
printf("VID: failed to read the volatge\n");
return ret;
}
/* Scale down to the real mV as LTC resolution is 1/4096V,rounding up */
vcode = DIV_ROUND_UP(vcode * 1000, 4096);
return vcode;
}
#endif
static int read_voltage(int i2caddress)
{
int voltage_read;
@@ -181,6 +211,8 @@ static int read_voltage(int i2caddress)
voltage_read = read_voltage_from_INA220(i2caddress);
#elif defined CONFIG_VOL_MONITOR_IR36021_READ
voltage_read = read_voltage_from_IR(i2caddress);
#elif defined CONFIG_VOL_MONITOR_LTC3882_READ
voltage_read = read_voltage_from_LTC(i2caddress);
#else
return -1;
#endif
@@ -281,6 +313,43 @@ static int set_voltage_to_IR(int i2caddress, int vdd)
debug("VID: Current voltage is %d mV\n", vdd_last);
return vdd_last;
}
#endif
#ifdef CONFIG_VOL_MONITOR_LTC3882_SET
/* this function sets the VDD and returns the value set */
static int set_voltage_to_LTC(int i2caddress, int vdd)
{
int ret, vdd_last, vdd_target = vdd;
/* Scale up to the LTC resolution is 1/4096V */
vdd = (vdd * 4096) / 1000;
/* 5-byte buffer which needs to be sent following the
* PMBus command PAGE_PLUS_WRITE.
*/
u8 buff[5] = {0x04, PWM_CHANNEL0, PMBUS_CMD_VOUT_COMMAND,
vdd & 0xFF, (vdd & 0xFF00) >> 8};
/* Write the desired voltage code to the regulator */
ret = i2c_write(I2C_VOL_MONITOR_ADDR,
PMBUS_CMD_PAGE_PLUS_WRITE, 1, (void *)&buff, 5);
if (ret) {
printf("VID: I2C failed to write to the volatge regulator\n");
return -1;
}
/* Wait for the volatge to get to the desired value */
do {
vdd_last = read_voltage_from_LTC(i2caddress);
if (vdd_last < 0) {
printf("VID: Couldn't read sensor abort VID adjust\n");
return -1;
}
} while (vdd_last != vdd_target);
return vdd_last;
}
#endif
static int set_voltage(int i2caddress, int vdd)
@@ -289,6 +358,8 @@ static int set_voltage(int i2caddress, int vdd)
#ifdef CONFIG_VOL_MONITOR_IR36021_SET
vdd_last = set_voltage_to_IR(i2caddress, vdd);
#elif defined CONFIG_VOL_MONITOR_LTC3882_SET
vdd_last = set_voltage_to_LTC(i2caddress, vdd);
#else
#error Specific voltage monitor must be defined
#endif
@@ -472,6 +543,11 @@ int adjust_vdd(ulong vdd_override)
}
vdd_current = vdd_last;
debug("VID: Core voltage is currently at %d mV\n", vdd_last);
#ifdef CONFIG_VOL_MONITOR_LTC3882_SET
/* Set the target voltage */
vdd_last = vdd_current = set_voltage(i2caddress, vdd_target);
#else
/*
* Adjust voltage to at or one step above target.
* As measurements are less precise than setting the values
@@ -489,6 +565,7 @@ int adjust_vdd(ulong vdd_override)
vdd_last = set_voltage(i2caddress, vdd_current);
}
#endif
if (board_adjust_vdd(vdd_target) < 0) {
ret = -1;
goto exit;