drivers/power/pmic/pmic_tps65218.c

   1 /*
   2  * (C) Copyright 2011-2013
   3  * Texas Instruments, <www.ti.com>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <i2c.h>
  10 #include <linux/errno.h>
  11 #include <power/pmic.h>
  12 #include <power/tps65218.h>
  13
  14 int tps65218_reg_read(uchar dest_reg, uchar *dest_val)
  15 {
  16         uchar read_val;
  17         int ret;
  18
  19         ret = i2c_read(TPS65218_CHIP_PM, dest_reg, 1, &read_val, 1);
  20         if (ret)
  21                 return ret;
  22
  23         *dest_val = read_val;
  24
  25         return 0;
  26 }
  27
  28 /**
  29  *  tps65218_reg_write() - Generic function that can write a TPS65218 PMIC
  30  *                         register or bit field regardless of protection
  31  *                         level.
  32  *
  33  *  @prot_level:           Register password protection.  Use
  34  *                         TPS65218_PROT_LEVEL_NONE,
  35  *                         TPS65218_PROT_LEVEL_1 or TPS65218_PROT_LEVEL_2
  36  *  @dest_reg:             Register address to write.
  37  *  @dest_val:             Value to write.
  38  *  @mask:                 Bit mask (8 bits) to be applied.  Function will only
  39  *                         change bits that are set in the bit mask.
  40  *
  41  *  @return:               0 for success, not 0 on failure, as per the i2c API
  42  */
  43 int tps65218_reg_write(uchar prot_level, uchar dest_reg, uchar dest_val,
  44                        uchar mask)
  45 {
  46         uchar read_val;
  47         uchar xor_reg;
  48         int ret;
  49
  50         /*
  51          * If we are affecting only a bit field, read dest_reg and apply the
  52          * mask
  53          */
  54         if (mask != TPS65218_MASK_ALL_BITS) {
  55                 ret = i2c_read(TPS65218_CHIP_PM, dest_reg, 1, &read_val, 1);
  56                 if (ret)
  57                         return ret;
  58                 read_val &= (~mask);
  59                 read_val |= (dest_val & mask);
  60                 dest_val = read_val;
  61         }
  62
  63         if (prot_level > 0) {
  64                 xor_reg = dest_reg ^ TPS65218_PASSWORD_UNLOCK;
  65                 ret = i2c_write(TPS65218_CHIP_PM, TPS65218_PASSWORD, 1,
  66                                 &xor_reg, 1);
  67                 if (ret)
  68                         return ret;
  69         }
  70
  71         ret = i2c_write(TPS65218_CHIP_PM, dest_reg, 1, &dest_val, 1);
  72         if (ret)
  73                 return ret;
  74
  75         if (prot_level == TPS65218_PROT_LEVEL_2) {
  76                 ret = i2c_write(TPS65218_CHIP_PM, TPS65218_PASSWORD, 1,
  77                                 &xor_reg, 1);
  78                 if (ret)
  79                         return ret;
  80
  81                 ret = i2c_write(TPS65218_CHIP_PM, dest_reg, 1, &dest_val, 1);
  82                 if (ret)
  83                         return ret;
  84         }
  85
  86         return 0;
  87 }
  88
  89 /**
  90  * tps65218_voltage_update() - Function to change a voltage level, as this
  91  *                             is a multi-step process.
  92  * @dc_cntrl_reg:              DC voltage control register to change.
  93  * @volt_sel:                  New value for the voltage register
  94  * @return:                    0 for success, not 0 on failure.
  95  */
  96 int tps65218_voltage_update(uchar dc_cntrl_reg, uchar volt_sel)
  97 {
  98         if ((dc_cntrl_reg != TPS65218_DCDC1) &&
  99             (dc_cntrl_reg != TPS65218_DCDC2))
 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 }