diff options
author | Ying Zhang <b40530@freescale.com> | 2014-10-31 18:06:18 +0800 |
---|---|---|
committer | York Sun <yorksun@freescale.com> | 2014-12-05 08:06:09 -0800 |
commit | 3ad2737ee3faa291f75176b667ac3ad4408b023d (patch) | |
tree | ae8af89395aeb105fc38d7a1f06f7740b754d789 /board/freescale/common/vid.c | |
parent | e7f533cd5972d762e0544a38c74fce495a9d9d2f (diff) | |
download | u-boot-imx-3ad2737ee3faa291f75176b667ac3ad4408b023d.zip u-boot-imx-3ad2737ee3faa291f75176b667ac3ad4408b023d.tar.gz u-boot-imx-3ad2737ee3faa291f75176b667ac3ad4408b023d.tar.bz2 |
powerpc/t208xqds: VID support
The fuse status register provides the values from on-chip
voltage ID efuses programmed at the factory.
These values define the voltage requirements for
the chip. u-boot reads FUSESR and translates the values
into the appropriate commands to set the voltage output
value of an external voltage regulator.
Signed-off-by: Ying Zhang <b40530@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
Diffstat (limited to 'board/freescale/common/vid.c')
-rw-r--r-- | board/freescale/common/vid.c | 491 |
1 files changed, 491 insertions, 0 deletions
diff --git a/board/freescale/common/vid.c b/board/freescale/common/vid.c new file mode 100644 index 0000000..6b8af14 --- /dev/null +++ b/board/freescale/common/vid.c @@ -0,0 +1,491 @@ +/* + * 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" +) |