drivers/power/pmic/pmic_tps65218.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2011-2013
   4  * Texas Instruments, <www.ti.com>
   5  */
   6
   7 #include <common.h>
   8 #include <i2c.h>
   9 #include <linux/errno.h>
  10 #include <power/pmic.h>
  11 #include <power/tps65218.h>
  12
  13 int tps65218_reg_read(uchar dest_reg, uchar *dest_val)
  14 {
  15         uchar read_val;
  16         int ret;
  17
  18         ret = i2c_read(TPS65218_CHIP_PM, dest_reg, 1, &read_val, 1);
  19         if (ret)
  20                 return ret;
  21
  22         *dest_val = read_val;
  23
  24         return 0;
  25 }
  26
  27 /**
  28  *  tps65218_reg_write() - Generic function that can write a TPS65218 PMIC
  29  *                         register or bit field regardless of protection
  30  *                         level.
  31  *
  32  *  @prot_level:           Register password protection.  Use
  33  *                         TPS65218_PROT_LEVEL_NONE,
  34  *                         TPS65218_PROT_LEVEL_1 or TPS65218_PROT_LEVEL_2
  35  *  @dest_reg:             Register address to write.
  36  *  @dest_val:             Value to write.
  37  *  @mask:                 Bit mask (8 bits) to be applied.  Function will only
  38  *                         change bits that are set in the bit mask.
  39  *
  40  *  @return:               0 for success, not 0 on failure, as per the i2c API
  41  */
  42 int tps65218_reg_write(uchar prot_level, uchar dest_reg, uchar dest_val,
  43                        uchar mask)
  44 {
  45         uchar read_val;
  46         uchar xor_reg;
  47         int ret;
  48
  49         /*
  50          * If we are affecting only a bit field, read dest_reg and apply the
  51          * mask
  52          */
  53         if (mask != TPS65218_MASK_ALL_BITS) {
  54                 ret = i2c_read(TPS65218_CHIP_PM, dest_reg, 1, &read_val, 1);
  55                 if (ret)
  56                         return ret;
  57                 read_val &= (~mask);
  58                 read_val |= (dest_val & mask);
  59                 dest_val = read_val;
  60         }
  61
  62         if (prot_level > 0) {
  63                 xor_reg = dest_reg ^ TPS65218_PASSWORD_UNLOCK;
  64                 ret = i2c_write(TPS65218_CHIP_PM, TPS65218_PASSWORD, 1,
  65                                 &xor_reg, 1);
  66                 if (ret)
  67                         return ret;
  68         }
  69
  70         ret = i2c_write(TPS65218_CHIP_PM, dest_reg, 1, &dest_val, 1);
  71         if (ret)
  72                 return ret;
  73
  74         if (prot_level == TPS65218_PROT_LEVEL_2) {
  75                 ret = i2c_write(TPS65218_CHIP_PM, TPS65218_PASSWORD, 1,
  76                                 &xor_reg, 1);
  77                 if (ret)
  78                         return ret;
  79
  80                 ret = i2c_write(TPS65218_CHIP_PM, dest_reg, 1, &dest_val, 1);
  81                 if (ret)
  82                         return ret;
  83         }
  84
  85         return 0;
  86 }
  87
  88 /**
  89  * tps65218_voltage_update() - Function to change a voltage level, as this
  90  *                             is a multi-step process.
  91  * @dc_cntrl_reg:              DC voltage control register to change.
  92  * @volt_sel:                  New value for the voltage register
  93  * @return:                    0 for success, not 0 on failure.
  94  */
  95 int tps65218_voltage_update(uchar dc_cntrl_reg, uchar volt_sel)
  96 {
  97         if ((dc_cntrl_reg != TPS65218_DCDC1) &&
  98             (dc_cntrl_reg != TPS65218_DCDC2) &&
  99             (dc_cntrl_reg != TPS65218_DCDC3))
 100                 return 1;
 101
 102         /* set voltage level */
 103         if (tps65218_reg_write(TPS65218_PROT_LEVEL_2, dc_cntrl_reg, volt_sel,
 104                                TPS65218_DCDC_VSEL_MASK))
 105                 return 1;
 106
 107         /* set GO bit to initiate voltage transition */
 108         if (tps65218_reg_write(TPS65218_PROT_LEVEL_2, TPS65218_SLEW,
 109                                TPS65218_DCDC_GO, TPS65218_DCDC_GO))
 110                 return 1;
 111
 112         return 0;
 113 }
 114
 115 /**
 116  * tps65218_toggle_fseal() - Perform the sequence that toggles the FSEAL bit.
 117  *
 118  * @return:                  0 on success, -EBADE if the sequence was broken
 119  */
 120 int tps65218_toggle_fseal(void)
 121 {
 122         if (tps65218_reg_write(TPS65218_PROT_LEVEL_NONE, TPS65218_PASSWORD,
 123                                0xb1, TPS65218_MASK_ALL_BITS))
 124                 return -EBADE;
 125
 126         if (tps65218_reg_write(TPS65218_PROT_LEVEL_NONE, TPS65218_PASSWORD,
 127                                0xfe, TPS65218_MASK_ALL_BITS))
 128                 return -EBADE;
 129
 130         if (tps65218_reg_write(TPS65218_PROT_LEVEL_NONE, TPS65218_PASSWORD,
 131                                0xa3, TPS65218_MASK_ALL_BITS))
 132                 return -EBADE;
 133
 134         return 0;
 135 }
 136
 137 /**
 138  * tps65218_lock_fseal() - Perform the sequence that locks the FSEAL bit to 1.
 139  *
 140  * The FSEAL bit prevents the PMIC from turning off DCDC5 and DCDC6. It can be
 141  * toggled at most 3 times: 0->1, 1->0, and finally 0->1. After the third switch
 142  * its value is locked and can only be reset by powering off the PMIC entirely.
 143  *
 144  * @return:                0 on success, -EBADE if the sequence was broken
 145  */
 146 int tps65218_lock_fseal(void)
 147 {
 148         int i;
 149
 150         for (i = 0; i < 3; i++)
 151                 if (tps65218_toggle_fseal())
 152                         return -EBADE;
 153
 154         return 0;
 155 }
 156
 157 int power_tps65218_init(unsigned char bus)
 158 {
 159         static const char name[] = "TPS65218_PMIC";
 160         struct pmic *p = pmic_alloc();
 161
 162         if (!p) {
 163                 printf("%s: POWER allocation error!\n", __func__);
 164                 return -ENOMEM;
 165         }
 166
 167         p->name = name;
 168         p->interface = PMIC_I2C;
 169         p->number_of_regs = TPS65218_PMIC_NUM_OF_REGS;
 170         p->hw.i2c.addr = TPS65218_CHIP_PM;
 171         p->hw.i2c.tx_num = 1;
 172         p->bus = bus;
 173
 174         return 0;
 175 }