u-boot/board/freescale/common/vid.c

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/*
* Copyright 2014 Freescale Semiconductor, Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <command.h>
#include <i2c.h>
#include <asm/immap_85xx.h>
#include "vid.h"
DECLARE_GLOBAL_DATA_PTR;
int __weak i2c_multiplexer_select_vid_channel(u8 channel)
{
return 0;
}
/*
* Compensate for a board specific voltage drop between regulator and SoC
* return a value in mV
*/
int __weak board_vdd_drop_compensation(void)
{
return 0;
}
/*
* Get the i2c address configuration for the IR regulator chip
*
* There are some variance in the RDB HW regarding the I2C address configuration
* for the IR regulator chip, which is likely a problem of external resistor
* accuracy. So we just check each address in a hopefully non-intrusive mode
* and use the first one that seems to work
*
* The IR chip can show up under the following addresses:
* 0x08 (Verified on T1040RDB-PA,T4240RDB-PB,X-T4240RDB-16GPA)
* 0x09 (Verified on T1040RDB-PA)
* 0x38 (Verified on T2080QDS, T2081QDS)
*/
static int find_ir_chip_on_i2c(void)
{
int i2caddress;
int ret;
u8 byte;
int i;
const int ir_i2c_addr[] = {0x38, 0x08, 0x09};
/* Check all the address */
for (i = 0; i < (sizeof(ir_i2c_addr)/sizeof(ir_i2c_addr[0])); i++) {
i2caddress = ir_i2c_addr[i];
ret = i2c_read(i2caddress,
IR36021_MFR_ID_OFFSET, 1, (void *)&byte,
sizeof(byte));
if ((ret >= 0) && (byte == IR36021_MFR_ID))
return i2caddress;
}
return -1;
}
/* Maximum loop count waiting for new voltage to take effect */
#define MAX_LOOP_WAIT_NEW_VOL 100
/* Maximum loop count waiting for the voltage to be stable */
#define MAX_LOOP_WAIT_VOL_STABLE 100
/*
* read_voltage from sensor on I2C bus
* We use average of 4 readings, waiting for WAIT_FOR_ADC before
* another reading
*/
#define NUM_READINGS 4 /* prefer to be power of 2 for efficiency */
/* If an INA220 chip is available, we can use it to read back the voltage
* as it may have a higher accuracy than the IR chip for the same purpose
*/
#ifdef CONFIG_VOL_MONITOR_INA220
#define WAIT_FOR_ADC 532 /* wait for 532 microseconds for ADC */
#define ADC_MIN_ACCURACY 4
#else
#define WAIT_FOR_ADC 138 /* wait for 138 microseconds for ADC */
#define ADC_MIN_ACCURACY 4
#endif
#ifdef CONFIG_VOL_MONITOR_INA220
static int read_voltage_from_INA220(int i2caddress)
{
int i, ret, voltage_read = 0;
u16 vol_mon;
u8 buf[2];
for (i = 0; i < NUM_READINGS; i++) {
ret = i2c_read(I2C_VOL_MONITOR_ADDR,
I2C_VOL_MONITOR_BUS_V_OFFSET, 1,
(void *)&buf, 2);
if (ret) {
printf("VID: failed to read core voltage\n");
return ret;
}
vol_mon = (buf[0] << 8) | buf[1];
if (vol_mon & I2C_VOL_MONITOR_BUS_V_OVF) {
printf("VID: Core voltage sensor error\n");
return -1;
}
debug("VID: bus voltage reads 0x%04x\n", vol_mon);
/* LSB = 4mv */
voltage_read += (vol_mon >> I2C_VOL_MONITOR_BUS_V_SHIFT) * 4;
udelay(WAIT_FOR_ADC);
}
/* calculate the average */
voltage_read /= NUM_READINGS;
return voltage_read;
}
#endif
/* read voltage from IR */
#ifdef CONFIG_VOL_MONITOR_IR36021_READ
static int read_voltage_from_IR(int i2caddress)
{
int i, ret, voltage_read = 0;
u16 vol_mon;
u8 buf;
for (i = 0; i < NUM_READINGS; i++) {
ret = i2c_read(i2caddress,
IR36021_LOOP1_VOUT_OFFSET,
1, (void *)&buf, 1);
if (ret) {
printf("VID: failed to read vcpu\n");
return ret;
}
vol_mon = buf;
if (!vol_mon) {
printf("VID: Core voltage sensor error\n");
return -1;
}
debug("VID: bus voltage reads 0x%02x\n", vol_mon);
/* Resolution is 1/128V. We scale up here to get 1/128mV
* and divide at the end
*/
voltage_read += vol_mon * 1000;
udelay(WAIT_FOR_ADC);
}
/* Scale down to the real mV as IR resolution is 1/128V, rounding up */
voltage_read = DIV_ROUND_UP(voltage_read, 128);
/* calculate the average */
voltage_read /= NUM_READINGS;
/* Compensate for a board specific voltage drop between regulator and
* SoC before converting into an IR VID value
*/
voltage_read -= board_vdd_drop_compensation();
return voltage_read;
}
#endif
static int read_voltage(int i2caddress)
{
int voltage_read;
#ifdef CONFIG_VOL_MONITOR_INA220
voltage_read = read_voltage_from_INA220(i2caddress);
#elif defined CONFIG_VOL_MONITOR_IR36021_READ
voltage_read = read_voltage_from_IR(i2caddress);
#else
return -1;
#endif
return voltage_read;
}
/*
* We need to calculate how long before the voltage stops to drop
* or increase. It returns with the loop count. Each loop takes
* several readings (WAIT_FOR_ADC)
*/
static int wait_for_new_voltage(int vdd, int i2caddress)
{
int timeout, vdd_current;
vdd_current = read_voltage(i2caddress);
/* wait until voltage starts to reach the target. Voltage slew
* rates by typical regulators will always lead to stable readings
* within each fairly long ADC interval in comparison to the
* intended voltage delta change until the target voltage is
* reached. The fairly small voltage delta change to any target
* VID voltage also means that this function will always complete
* within few iterations. If the timeout was ever reached, it would
* point to a serious failure in the regulator system.
*/
for (timeout = 0;
abs(vdd - vdd_current) > (IR_VDD_STEP_UP + IR_VDD_STEP_DOWN) &&
timeout < MAX_LOOP_WAIT_NEW_VOL; timeout++) {
vdd_current = read_voltage(i2caddress);
}
if (timeout >= MAX_LOOP_WAIT_NEW_VOL) {
printf("VID: Voltage adjustment timeout\n");
return -1;
}
return timeout;
}
/*
* this function keeps reading the voltage until it is stable or until the
* timeout expires
*/
static int wait_for_voltage_stable(int i2caddress)
{
int timeout, vdd_current, vdd;
vdd = read_voltage(i2caddress);
udelay(NUM_READINGS * WAIT_FOR_ADC);
/* wait until voltage is stable */
vdd_current = read_voltage(i2caddress);
/* The maximum timeout is
* MAX_LOOP_WAIT_VOL_STABLE * NUM_READINGS * WAIT_FOR_ADC
*/
for (timeout = MAX_LOOP_WAIT_VOL_STABLE;
abs(vdd - vdd_current) > ADC_MIN_ACCURACY &&
timeout > 0; timeout--) {
vdd = vdd_current;
udelay(NUM_READINGS * WAIT_FOR_ADC);
vdd_current = read_voltage(i2caddress);
}
if (timeout == 0)
return -1;
return vdd_current;
}
#ifdef CONFIG_VOL_MONITOR_IR36021_SET
/* Set the voltage to the IR chip */
static int set_voltage_to_IR(int i2caddress, int vdd)
{
int wait, vdd_last;
int ret;
u8 vid;
/* Compensate for a board specific voltage drop between regulator and
* SoC before converting into an IR VID value
*/
vdd += board_vdd_drop_compensation();
vid = DIV_ROUND_UP(vdd - 245, 5);
ret = i2c_write(i2caddress, IR36021_LOOP1_MANUAL_ID_OFFSET,
1, (void *)&vid, sizeof(vid));
if (ret) {
printf("VID: failed to write VID\n");
return -1;
}
wait = wait_for_new_voltage(vdd, i2caddress);
if (wait < 0)
return -1;
debug("VID: Waited %d us\n", wait * NUM_READINGS * WAIT_FOR_ADC);
vdd_last = wait_for_voltage_stable(i2caddress);
if (vdd_last < 0)
return -1;
debug("VID: Current voltage is %d mV\n", vdd_last);
return vdd_last;
}
#endif
static int set_voltage(int i2caddress, int vdd)
{
int vdd_last = -1;
#ifdef CONFIG_VOL_MONITOR_IR36021_SET
vdd_last = set_voltage_to_IR(i2caddress, vdd);
#else
#error Specific voltage monitor must be defined
#endif
return vdd_last;
}
int adjust_vdd(ulong vdd_override)
{
int re_enable = disable_interrupts();
ccsr_gur_t __iomem *gur =
(void __iomem *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
u32 fusesr;
u8 vid;
int vdd_target, vdd_current, vdd_last;
int ret, i2caddress;
unsigned long vdd_string_override;
char *vdd_string;
static const uint16_t vdd[32] = {
0, /* unused */
9875, /* 0.9875V */
9750,
9625,
9500,
9375,
9250,
9125,
9000,
8875,
8750,
8625,
8500,
8375,
8250,
8125,
10000, /* 1.0000V */
10125,
10250,
10375,
10500,
10625,
10750,
10875,
11000,
0, /* reserved */
};
struct vdd_drive {
u8 vid;
unsigned voltage;
};
ret = i2c_multiplexer_select_vid_channel(I2C_MUX_CH_VOL_MONITOR);
if (ret) {
debug("VID: I2C failed to switch channel\n");
ret = -1;
goto exit;
}
ret = find_ir_chip_on_i2c();
if (ret < 0) {
printf("VID: Could not find voltage regulator on I2C.\n");
ret = -1;
goto exit;
} else {
i2caddress = ret;
debug("VID: IR Chip found on I2C address 0x%02x\n", i2caddress);
}
/* get the voltage ID from fuse status register */
fusesr = in_be32(&gur->dcfg_fusesr);
/*
* VID is used according to the table below
* ---------------------------------------
* | DA_V |
* |-------------------------------------|
* | 5b00000 | 5b00001-5b11110 | 5b11111 |
* ---------------+---------+-----------------+---------|
* | D | 5b00000 | NO VID | VID = DA_V | NO VID |
* | A |----------+---------+-----------------+---------|
* | _ | 5b00001 |VID = | VID = |VID = |
* | V | ~ | DA_V_ALT| DA_V_ALT | DA_A_VLT|
* | _ | 5b11110 | | | |
* | A |----------+---------+-----------------+---------|
* | L | 5b11111 | No VID | VID = DA_V | NO VID |
* | T | | | | |
* ------------------------------------------------------
*/
vid = (fusesr >> FSL_CORENET_DCFG_FUSESR_ALTVID_SHIFT) &
FSL_CORENET_DCFG_FUSESR_ALTVID_MASK;
if ((vid == 0) || (vid == FSL_CORENET_DCFG_FUSESR_ALTVID_MASK)) {
vid = (fusesr >> FSL_CORENET_DCFG_FUSESR_VID_SHIFT) &
FSL_CORENET_DCFG_FUSESR_VID_MASK;
}
vdd_target = vdd[vid];
/* check override variable for overriding VDD */
vdd_string = getenv(CONFIG_VID_FLS_ENV);
if (vdd_override == 0 && vdd_string &&
!strict_strtoul(vdd_string, 10, &vdd_string_override))
vdd_override = vdd_string_override;
if (vdd_override >= VDD_MV_MIN && vdd_override <= VDD_MV_MAX) {
vdd_target = vdd_override * 10; /* convert to 1/10 mV */
debug("VDD override is %lu\n", vdd_override);
} else if (vdd_override != 0) {
printf("Invalid value.\n");
}
if (vdd_target == 0) {
debug("VID: VID not used\n");
ret = 0;
goto exit;
} else {
/* divide and round up by 10 to get a value in mV */
vdd_target = DIV_ROUND_UP(vdd_target, 10);
debug("VID: vid = %d mV\n", vdd_target);
}
/*
* Read voltage monitor to check real voltage.
*/
vdd_last = read_voltage(i2caddress);
if (vdd_last < 0) {
printf("VID: Couldn't read sensor abort VID adjustment\n");
ret = -1;
goto exit;
}
vdd_current = vdd_last;
debug("VID: Core voltage is currently at %d mV\n", vdd_last);
/*
* Adjust voltage to at or one step above target.
* As measurements are less precise than setting the values
* we may run through dummy steps that cancel each other
* when stepping up and then down.
*/
while (vdd_last > 0 &&
vdd_last < vdd_target) {
vdd_current += IR_VDD_STEP_UP;
vdd_last = set_voltage(i2caddress, vdd_current);
}
while (vdd_last > 0 &&
vdd_last > vdd_target + (IR_VDD_STEP_DOWN - 1)) {
vdd_current -= IR_VDD_STEP_DOWN;
vdd_last = set_voltage(i2caddress, vdd_current);
}
if (vdd_last > 0)
printf("VID: Core voltage after adjustment is at %d mV\n",
vdd_last);
else
ret = -1;
exit:
if (re_enable)
enable_interrupts();
return ret;
}
static int print_vdd(void)
{
int vdd_last, ret, i2caddress;
ret = i2c_multiplexer_select_vid_channel(I2C_MUX_CH_VOL_MONITOR);
if (ret) {
debug("VID : I2c failed to switch channel\n");
return -1;
}
ret = find_ir_chip_on_i2c();
if (ret < 0) {
printf("VID: Could not find voltage regulator on I2C.\n");
return -1;
} else {
i2caddress = ret;
debug("VID: IR Chip found on I2C address 0x%02x\n", i2caddress);
}
/*
* Read voltage monitor to check real voltage.
*/
vdd_last = read_voltage(i2caddress);
if (vdd_last < 0) {
printf("VID: Couldn't read sensor abort VID adjustment\n");
return -1;
}
printf("VID: Core voltage is at %d mV\n", vdd_last);
return 0;
}
static int do_vdd_override(cmd_tbl_t *cmdtp,
int flag, int argc,
char * const argv[])
{
ulong override;
if (argc < 2)
return CMD_RET_USAGE;
if (!strict_strtoul(argv[1], 10, &override))
adjust_vdd(override); /* the value is checked by callee */
else
return CMD_RET_USAGE;
return 0;
}
static int do_vdd_read(cmd_tbl_t *cmdtp,
int flag, int argc,
char * const argv[])
{
if (argc < 1)
return CMD_RET_USAGE;
print_vdd();
return 0;
}
U_BOOT_CMD(
vdd_override, 2, 0, do_vdd_override,
"override VDD",
" - override with the voltage specified in mV, eg. 1050"
);
U_BOOT_CMD(
vdd_read, 1, 0, do_vdd_read,
"read VDD",
" - Read the voltage specified in mV"
)