drivers/power/tps6586x.c

   1 /*
   2  * Copyright (c) 2011 The Chromium OS Authors.
   3  * (C) Copyright 2010,2011 NVIDIA Corporation <www.nvidia.com>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <tps6586x.h>
  10 #include <asm/io.h>
  11 #include <i2c.h>
  12
  13 static struct udevice *tps6586x_dev;
  14
  15 enum {
  16         /* Registers that we access */
  17         SUPPLY_CONTROL1         = 0x20,
  18         SUPPLY_CONTROL2,
  19         SM1_VOLTAGE_V1          = 0x23,
  20         SM1_VOLTAGE_V2,
  21         SM0_VOLTAGE_V1          = 0x26,
  22         SM0_VOLTAGE_V2,
  23         PFM_MODE                = 0x47,
  24
  25         /* Bits in the supply control registers */
  26         CTRL_SM1_RAMP           = 0x01,
  27         CTRL_SM1_SUPPLY2        = 0x02,
  28         CTRL_SM0_RAMP           = 0x04,
  29         CTRL_SM0_SUPPLY2        = 0x08,
  30 };
  31
  32 #define MAX_I2C_RETRY   3
  33 static int tps6586x_read(int reg)
  34 {
  35         int     i;
  36         uchar   data;
  37         int     retval = -1;
  38
  39         for (i = 0; i < MAX_I2C_RETRY; ++i) {
  40                 if (!dm_i2c_read(tps6586x_dev, reg,  &data, 1)) {
  41                         retval = (int)data;
  42                         goto exit;
  43                 }
  44
  45                 /* i2c access failed, retry */
  46                 udelay(100);
  47         }
  48
  49 exit:
  50         debug("pmu_read %x=%x\n", reg, retval);
  51         if (retval < 0)
  52                 debug("%s: failed to read register %#x: %d\n", __func__, reg,
  53                       retval);
  54         return retval;
  55 }
  56
  57 static int tps6586x_write(int reg, uchar *data, uint len)
  58 {
  59         int     i;
  60         int     retval = -1;
  61
  62         for (i = 0; i < MAX_I2C_RETRY; ++i) {
  63                 if (!dm_i2c_write(tps6586x_dev, reg, data, len)) {
  64                         retval = 0;
  65                         goto exit;
  66                 }
  67
  68                 /* i2c access failed, retry */
  69                 udelay(100);
  70         }
  71
  72 exit:
  73         debug("pmu_write %x=%x: ", reg, retval);
  74         for (i = 0; i < len; i++)
  75                 debug("%x ", data[i]);
  76         if (retval)
  77                 debug("%s: failed to write register %#x\n", __func__, reg);
  78         return retval;
  79 }
  80
  81 /*
  82  * Get current voltage of SM0 and SM1
  83  *
  84  * @param sm0   Place to put SM0 voltage
  85  * @param sm1   Place to put SM1 voltage
  86  * @return 0 if ok, -1 on error
  87  */
  88 static int read_voltages(int *sm0, int *sm1)
  89 {
  90         int ctrl1, ctrl2;
  91         int is_v2;
  92
  93         /*
  94          * Each vdd has two supply sources, ie, v1 and v2.
  95          * The supply control reg1 and reg2 determine the current selection.
  96          */
  97         ctrl1 = tps6586x_read(SUPPLY_CONTROL1);
  98         ctrl2 = tps6586x_read(SUPPLY_CONTROL2);
  99         if (ctrl1 == -1 || ctrl2 == -1)
 100                 return -ENOTSUPP;
 101
 102         /* Figure out whether V1 or V2 is selected */
 103         is_v2 = (ctrl1 | ctrl2) & CTRL_SM0_SUPPLY2;
 104         *sm0 = tps6586x_read(is_v2 ? SM0_VOLTAGE_V2 : SM0_VOLTAGE_V1);
 105         *sm1 = tps6586x_read(is_v2 ? SM1_VOLTAGE_V2 : SM1_VOLTAGE_V1);
 106         if (*sm0 == -1 || *sm1 == -1)
 107                 return -ENOTSUPP;
 108
 109         return 0;
 110 }
 111
 112 static int set_voltage(int reg, int data, int rate)
 113 {
 114         uchar control_bit;
 115         uchar buff[3];
 116
 117         control_bit = (reg == SM0_VOLTAGE_V1 ? CTRL_SM0_RAMP : CTRL_SM1_RAMP);
 118
 119         /*
 120          * Only one supply is needed in u-boot. set both v1 and v2 to
 121          * same value.
 122          *
 123          * When both v1 and v2 are set to same value, we just need to set
 124          * control1 reg to trigger the supply selection.
 125          */
 126         buff[0] = buff[1] = (uchar)data;
 127         buff[2] = rate;
 128
 129         /* write v1, v2 and rate, then trigger */
 130         if (tps6586x_write(reg, buff, 3) ||
 131             tps6586x_write(SUPPLY_CONTROL1, &control_bit, 1))
 132                 return -ENOTSUPP;
 133
 134         return 0;
 135 }
 136
 137 static int calculate_next_voltage(int voltage, int target, int step)
 138 {
 139         int diff = voltage < target ? step : -step;
 140
 141         if (abs(target - voltage) > step)
 142                 voltage += diff;
 143         else
 144                 voltage = target;
 145
 146         return voltage;
 147 }
 148
 149 int tps6586x_set_pwm_mode(int mask)
 150 {
 151         uchar val;
 152         int ret;
 153
 154         assert(tps6586x_dev);
 155         ret = tps6586x_read(PFM_MODE);
 156         if (ret != -1) {
 157                 val = (uchar)ret;
 158                 val |= mask;
 159
 160                 ret = tps6586x_write(PFM_MODE, &val, 1);
 161         }
 162
 163         if (ret == -1)
 164                 debug("%s: Failed to read/write PWM mode reg\n", __func__);
 165
 166         return ret;
 167 }
 168
 169 int tps6586x_adjust_sm0_sm1(int sm0_target, int sm1_target, int step, int rate,
 170                             int min_sm0_over_sm1)
 171 {
 172         int sm0, sm1;
 173         int bad;
 174
 175         assert(tps6586x_dev);
 176
 177         /* get current voltage settings */
 178         if (read_voltages(&sm0, &sm1)) {
 179                 debug("%s: Cannot read voltage settings\n", __func__);
 180                 return -EINVAL;
 181         }
 182
 183         /*
 184          * if vdd_core < vdd_cpu + rel
 185          *    skip
 186          *
 187          * This condition may happen when system reboots due to kernel crash.
 188          */
 189         if (min_sm0_over_sm1 != -1 && sm0 < sm1 + min_sm0_over_sm1) {
 190                 debug("%s: SM0 is %d, SM1 is %d, but min_sm0_over_sm1 is %d\n",
 191                       __func__, sm0, sm1, min_sm0_over_sm1);
 192                 return -EINVAL;
 193         }
 194
 195         /*
 196          * Since vdd_core and vdd_cpu may both stand at either greater or less
 197          * than their nominal voltage, the adjustment may go either directions.
 198          *
 199          * Make sure vdd_core is always higher than vdd_cpu with certain margin.
 200          * So, find out which vdd to adjust first in each step.
 201          *
 202          * case 1: both sm0 and sm1 need to move up
 203          *              adjust sm0 before sm1
 204          *
 205          * case 2: both sm0 and sm1 need to move down
 206          *              adjust sm1 before sm0
 207          *
 208          * case 3: sm0 moves down and sm1 moves up
 209          *              adjusting either one first is fine.
 210          *
 211          * Adjust vdd_core and vdd_cpu one step at a time until they reach
 212          * their nominal values.
 213          */
 214         bad = 0;
 215         while (!bad && (sm0 != sm0_target || sm1 != sm1_target)) {
 216                 int adjust_sm0_late = 0; /* flag to adjust vdd_core later */
 217
 218                 debug("%d-%d   %d-%d   ", sm0, sm0_target, sm1, sm1_target);
 219
 220                 if (sm0 != sm0_target) {
 221                         /*
 222                          * if case 1 and case 3, set new sm0 first.
 223                          * otherwise, hold down until new sm1 is set.
 224                          */
 225                         sm0 = calculate_next_voltage(sm0, sm0_target, step);
 226                         if (sm1 < sm1_target)
 227                                 bad |= set_voltage(SM0_VOLTAGE_V1, sm0, rate);
 228                         else
 229                                 adjust_sm0_late = 1;
 230                 }
 231
 232                 if (sm1 != sm1_target) {
 233                         sm1 = calculate_next_voltage(sm1, sm1_target, step);
 234                         bad |= set_voltage(SM1_VOLTAGE_V1, sm1, rate);
 235                 }
 236
 237                 if (adjust_sm0_late)
 238                         bad |= set_voltage(SM0_VOLTAGE_V1, sm0, rate);
 239                 debug("%d\n", adjust_sm0_late);
 240         }
 241         debug("%d-%d   %d-%d   done\n", sm0, sm0_target, sm1, sm1_target);
 242
 243         return bad ? -EINVAL : 0;
 244 }
 245
 246 int tps6586x_init(struct udevice *dev)
 247 {
 248         tps6586x_dev = dev;
 249
 250         return 0;
 251 }