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>
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"
+)