/* * Copyright 2014 Freescale Semiconductor, Inc. * * SPDX-License-Identifier: GPL-2.0+ */ #include #include #include #include #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" )