drivers/mfd/88pm860x-i2c.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * I2C driver for Marvell 88PM860x
   4  *
   5  * Copyright (C) 2009 Marvell International Ltd.
   6  *
   7  * Author: Haojian Zhuang <haojian.zhuang@marvell.com>
   8  */
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/i2c.h>
  12 #include <linux/regmap.h>
  13 #include <linux/mfd/88pm860x.h>
  14
  15 int pm860x_reg_read(struct i2c_client *i2c, int reg)
  16 {
  17         struct pm860x_chip *chip = i2c_get_clientdata(i2c);
  18         struct regmap *map = (i2c == chip->client) ? chip->regmap
  19                                 : chip->regmap_companion;
  20         unsigned int data;
  21         int ret;
  22
  23         ret = regmap_read(map, reg, &data);
  24         if (ret < 0)
  25                 return ret;
  26         else
  27                 return (int)data;
  28 }
  29 EXPORT_SYMBOL(pm860x_reg_read);
  30
  31 int pm860x_reg_write(struct i2c_client *i2c, int reg,
  32                      unsigned char data)
  33 {
  34         struct pm860x_chip *chip = i2c_get_clientdata(i2c);
  35         struct regmap *map = (i2c == chip->client) ? chip->regmap
  36                                 : chip->regmap_companion;
  37         int ret;
  38
  39         ret = regmap_write(map, reg, data);
  40         return ret;
  41 }
  42 EXPORT_SYMBOL(pm860x_reg_write);
  43
  44 int pm860x_bulk_read(struct i2c_client *i2c, int reg,
  45                      int count, unsigned char *buf)
  46 {
  47         struct pm860x_chip *chip = i2c_get_clientdata(i2c);
  48         struct regmap *map = (i2c == chip->client) ? chip->regmap
  49                                 : chip->regmap_companion;
  50         int ret;
  51
  52         ret = regmap_raw_read(map, reg, buf, count);
  53         return ret;
  54 }
  55 EXPORT_SYMBOL(pm860x_bulk_read);
  56
  57 int pm860x_bulk_write(struct i2c_client *i2c, int reg,
  58                       int count, unsigned char *buf)
  59 {
  60         struct pm860x_chip *chip = i2c_get_clientdata(i2c);
  61         struct regmap *map = (i2c == chip->client) ? chip->regmap
  62                                 : chip->regmap_companion;
  63         int ret;
  64
  65         ret = regmap_raw_write(map, reg, buf, count);
  66         return ret;
  67 }
  68 EXPORT_SYMBOL(pm860x_bulk_write);
  69
  70 int pm860x_set_bits(struct i2c_client *i2c, int reg,
  71                     unsigned char mask, unsigned char data)
  72 {
  73         struct pm860x_chip *chip = i2c_get_clientdata(i2c);
  74         struct regmap *map = (i2c == chip->client) ? chip->regmap
  75                                 : chip->regmap_companion;
  76         int ret;
  77
  78         ret = regmap_update_bits(map, reg, mask, data);
  79         return ret;
  80 }
  81 EXPORT_SYMBOL(pm860x_set_bits);
  82
  83 static int read_device(struct i2c_client *i2c, int reg,
  84                        int bytes, void *dest)
  85 {
  86         unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX + 3];
  87         unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX + 2];
  88         struct i2c_adapter *adap = i2c->adapter;
  89         struct i2c_msg msg[2] = {
  90                                         {
  91                                                 .addr = i2c->addr,
  92                                                 .flags = 0,
  93                                                 .len = 1,
  94                                                 .buf = msgbuf0
  95                                         },
  96                                         {       .addr = i2c->addr,
  97                                                 .flags = I2C_M_RD,
  98                                                 .len = 0,
  99                                                 .buf = msgbuf1
 100                                         },
 101                                 };
 102         int num = 1, ret = 0;
 103
 104         if (dest == NULL)
 105                 return -EINVAL;
 106         msgbuf0[0] = (unsigned char)reg;        /* command */
 107         msg[1].len = bytes;
 108
 109         /* if data needs to read back, num should be 2 */
 110         if (bytes > 0)
 111                 num = 2;
 112         ret = adap->algo->master_xfer(adap, msg, num);
 113         memcpy(dest, msgbuf1, bytes);
 114         if (ret < 0)
 115                 return ret;
 116         return 0;
 117 }
 118
 119 static int write_device(struct i2c_client *i2c, int reg,
 120                         int bytes, void *src)
 121 {
 122         unsigned char buf[2];
 123         struct i2c_adapter *adap = i2c->adapter;
 124         struct i2c_msg msg;
 125         int ret;
 126
 127         buf[0] = (unsigned char)reg;
 128         memcpy(&buf[1], src, bytes);
 129         msg.addr = i2c->addr;
 130         msg.flags = 0;
 131         msg.len = bytes + 1;
 132         msg.buf = buf;
 133
 134         ret = adap->algo->master_xfer(adap, &msg, 1);
 135         if (ret < 0)
 136                 return ret;
 137         return 0;
 138 }
 139
 140 int pm860x_page_reg_write(struct i2c_client *i2c, int reg,
 141                           unsigned char data)
 142 {
 143         unsigned char zero;
 144         int ret;
 145
 146         i2c_lock_bus(i2c->adapter, I2C_LOCK_SEGMENT);
 147         read_device(i2c, 0xFA, 0, &zero);
 148         read_device(i2c, 0xFB, 0, &zero);
 149         read_device(i2c, 0xFF, 0, &zero);
 150         ret = write_device(i2c, reg, 1, &data);
 151         read_device(i2c, 0xFE, 0, &zero);
 152         read_device(i2c, 0xFC, 0, &zero);
 153         i2c_unlock_bus(i2c->adapter, I2C_LOCK_SEGMENT);
 154         return ret;
 155 }
 156 EXPORT_SYMBOL(pm860x_page_reg_write);
 157
 158 int pm860x_page_bulk_read(struct i2c_client *i2c, int reg,
 159                           int count, unsigned char *buf)
 160 {
 161         unsigned char zero = 0;
 162         int ret;
 163
 164         i2c_lock_bus(i2c->adapter, I2C_LOCK_SEGMENT);
 165         read_device(i2c, 0xfa, 0, &zero);
 166         read_device(i2c, 0xfb, 0, &zero);
 167         read_device(i2c, 0xff, 0, &zero);
 168         ret = read_device(i2c, reg, count, buf);
 169         read_device(i2c, 0xFE, 0, &zero);
 170         read_device(i2c, 0xFC, 0, &zero);
 171         i2c_unlock_bus(i2c->adapter, I2C_LOCK_SEGMENT);
 172         return ret;
 173 }
 174 EXPORT_SYMBOL(pm860x_page_bulk_read);