drivers/power/pmic/pmic_tps65090_ec.c

   1 /*
   2  * Copyright (c) 2013 The Chromium OS Authors.
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #include <common.h>
   8 #include <cros_ec.h>
   9 #include <errno.h>
  10 #include <power/tps65090_pmic.h>
  11
  12 DECLARE_GLOBAL_DATA_PTR;
  13
  14 #define TPS65090_ADDR           0x48
  15
  16 static struct tps65090 {
  17         struct cros_ec_dev *dev;                /* The CROS_EC device */
  18 } config;
  19
  20 /* TPS65090 register addresses */
  21 enum {
  22         REG_IRQ1 = 0,
  23         REG_CG_CTRL0 = 4,
  24         REG_CG_STATUS1 = 0xa,
  25         REG_FET1_CTRL = 0x0f,
  26         REG_FET2_CTRL,
  27         REG_FET3_CTRL,
  28         REG_FET4_CTRL,
  29         REG_FET5_CTRL,
  30         REG_FET6_CTRL,
  31         REG_FET7_CTRL,
  32         TPS65090_NUM_REGS,
  33 };
  34
  35 enum {
  36         IRQ1_VBATG = 1 << 3,
  37         CG_CTRL0_ENC_MASK       = 0x01,
  38
  39         MAX_FET_NUM     = 7,
  40         MAX_CTRL_READ_TRIES = 5,
  41
  42         /* TPS65090 FET_CTRL register values */
  43         FET_CTRL_TOFET          = 1 << 7,  /* Timeout, startup, overload */
  44         FET_CTRL_PGFET          = 1 << 4,  /* Power good for FET status */
  45         FET_CTRL_WAIT           = 3 << 2,  /* Overcurrent timeout max */
  46         FET_CTRL_ADENFET        = 1 << 1,  /* Enable output auto discharge */
  47         FET_CTRL_ENFET          = 1 << 0,  /* Enable FET */
  48 };
  49
  50 /**
  51  * tps65090_read - read a byte from tps6090
  52  *
  53  * @param reg           The register address to read from.
  54  * @param val           We'll return value value read here.
  55  * @return 0 if ok; error if EC returns failure.
  56  */
  57 static int tps65090_read(u32 reg, u8 *val)
  58 {
  59         return cros_ec_i2c_xfer_old(config.dev, TPS65090_ADDR, reg, 1,
  60                                     val, 1, true);
  61 }
  62
  63 /**
  64  * tps65090_write - write a byte to tps6090
  65  *
  66  * @param reg           The register address to write to.
  67  * @param val           The value to write.
  68  * @return 0 if ok; error if EC returns failure.
  69  */
  70 static int tps65090_write(u32 reg, u8 val)
  71 {
  72         return cros_ec_i2c_xfer_old(config.dev, TPS65090_ADDR, reg, 1,
  73                                     &val, 1, false);
  74 }
  75
  76 /**
  77  * Checks for a valid FET number
  78  *
  79  * @param fet_id        FET number to check
  80  * @return 0 if ok, -EINVAL if FET value is out of range
  81  */
  82 static int tps65090_check_fet(unsigned int fet_id)
  83 {
  84         if (fet_id == 0 || fet_id > MAX_FET_NUM) {
  85                 debug("parameter fet_id is out of range, %u not in 1 ~ %u\n",
  86                       fet_id, MAX_FET_NUM);
  87                 return -EINVAL;
  88         }
  89
  90         return 0;
  91 }
  92
  93 /**
  94  * Set the power state for a FET
  95  *
  96  * @param fet_id        Fet number to set (1..MAX_FET_NUM)
  97  * @param set           1 to power on FET, 0 to power off
  98  * @return -EIO if we got a comms error, -EAGAIN if the FET failed to
  99  * change state. If all is ok, returns 0.
 100  */
 101 static int tps65090_fet_set(int fet_id, bool set)
 102 {
 103         int retry;
 104         u8 reg, value;
 105
 106         value = FET_CTRL_ADENFET | FET_CTRL_WAIT;
 107         if (set)
 108                 value |= FET_CTRL_ENFET;
 109
 110         if (tps65090_write(REG_FET1_CTRL + fet_id - 1, value))
 111                 return -EIO;
 112
 113         /* Try reading until we get a result */
 114         for (retry = 0; retry < MAX_CTRL_READ_TRIES; retry++) {
 115                 if (tps65090_read(REG_FET1_CTRL + fet_id - 1, &reg))
 116                         return -EIO;
 117
 118                 /* Check that the fet went into the expected state */
 119                 if (!!(reg & FET_CTRL_PGFET) == set)
 120                         return 0;
 121
 122                 /* If we got a timeout, there is no point in waiting longer */
 123                 if (reg & FET_CTRL_TOFET)
 124                         break;
 125
 126                 mdelay(1);
 127         }
 128
 129         debug("FET %d: Power good should have set to %d but reg=%#02x\n",
 130               fet_id, set, reg);
 131         return -EAGAIN;
 132 }
 133
 134 int tps65090_fet_enable(unsigned int fet_id)
 135 {
 136         ulong start;
 137         int loops;
 138         int ret;
 139
 140         ret = tps65090_check_fet(fet_id);
 141         if (ret)
 142                 return ret;
 143
 144         start = get_timer(0);
 145         for (loops = 0;; loops++) {
 146                 ret = tps65090_fet_set(fet_id, true);
 147                 if (!ret)
 148                         break;
 149
 150                 if (get_timer(start) > 100)
 151                         break;
 152
 153                 /* Turn it off and try again until we time out */
 154                 tps65090_fet_set(fet_id, false);
 155         }
 156
 157         if (ret) {
 158                 debug("%s: FET%d failed to power on: time=%lums, loops=%d\n",
 159                       __func__, fet_id, get_timer(start), loops);
 160         } else if (loops) {
 161                 debug("%s: FET%d powered on after %lums, loops=%d\n",
 162                       __func__, fet_id, get_timer(start), loops);
 163         }
 164         /*
 165          * Unfortunately, there are some conditions where the power
 166          * good bit will be 0, but the fet still comes up. One such
 167          * case occurs with the lcd backlight. We'll just return 0 here
 168          * and assume that the fet will eventually come up.
 169          */
 170         if (ret == -EAGAIN)
 171                 ret = 0;
 172
 173         return ret;
 174 }
 175
 176 int tps65090_fet_disable(unsigned int fet_id)
 177 {
 178         int ret;
 179
 180         ret = tps65090_check_fet(fet_id);
 181         if (ret)
 182                 return ret;
 183
 184         ret = tps65090_fet_set(fet_id, false);
 185
 186         return ret;
 187 }
 188
 189 int tps65090_fet_is_enabled(unsigned int fet_id)
 190 {
 191         u8 reg = 0;
 192         int ret;
 193
 194         ret = tps65090_check_fet(fet_id);
 195         if (ret)
 196                 return ret;
 197         ret = tps65090_read(REG_FET1_CTRL + fet_id - 1, &reg);
 198         if (ret) {
 199                 debug("fail to read FET%u_CTRL register over I2C", fet_id);
 200                 return -EIO;
 201         }
 202
 203         return reg & FET_CTRL_ENFET;
 204 }
 205
 206 int tps65090_init(void)
 207 {
 208         puts("TPS65090 PMIC EC init\n");
 209
 210         config.dev = board_get_cros_ec_dev();
 211         if (!config.dev) {
 212                 debug("%s: no cros_ec device: cannot init tps65090\n",
 213                       __func__);
 214                 return -ENODEV;
 215         }
 216
 217         return 0;
 218 }