kernel/drivers/base/regmap/regmap-spmi.c

   1 /*
   2  * Register map access API - SPMI support
   3  *
   4  * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
   5  *
   6  * Based on regmap-i2c.c:
   7  * Copyright 2011 Wolfson Microelectronics plc
   8  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 and
  12  * only version 2 as published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  */
  20 #include <linux/regmap.h>
  21 #include <linux/spmi.h>
  22 #include <linux/module.h>
  23 #include <linux/init.h>
  24
  25 static int regmap_spmi_base_read(void *context,
  26                                  const void *reg, size_t reg_size,
  27                                  void *val, size_t val_size)
  28 {
  29         u8 addr = *(u8 *)reg;
  30         int err = 0;
  31
  32         BUG_ON(reg_size != 1);
  33
  34         while (val_size-- && !err)
  35                 err = spmi_register_read(context, addr++, val++);
  36
  37         return err;
  38 }
  39
  40 static int regmap_spmi_base_gather_write(void *context,
  41                                          const void *reg, size_t reg_size,
  42                                          const void *val, size_t val_size)
  43 {
  44         const u8 *data = val;
  45         u8 addr = *(u8 *)reg;
  46         int err = 0;
  47
  48         BUG_ON(reg_size != 1);
  49
  50         /*
  51          * SPMI defines a more bandwidth-efficient 'Register 0 Write' sequence,
  52          * use it when possible.
  53          */
  54         if (addr == 0 && val_size) {
  55                 err = spmi_register_zero_write(context, *data);
  56                 if (err)
  57                         goto err_out;
  58
  59                 data++;
  60                 addr++;
  61                 val_size--;
  62         }
  63
  64         while (val_size) {
  65                 err = spmi_register_write(context, addr, *data);
  66                 if (err)
  67                         goto err_out;
  68
  69                 data++;
  70                 addr++;
  71                 val_size--;
  72         }
  73
  74 err_out:
  75         return err;
  76 }
  77
  78 static int regmap_spmi_base_write(void *context, const void *data,
  79                                   size_t count)
  80 {
  81         BUG_ON(count < 1);
  82         return regmap_spmi_base_gather_write(context, data, 1, data + 1,
  83                                              count - 1);
  84 }
  85
  86 static struct regmap_bus regmap_spmi_base = {
  87         .read                           = regmap_spmi_base_read,
  88         .write                          = regmap_spmi_base_write,
  89         .gather_write                   = regmap_spmi_base_gather_write,
  90         .reg_format_endian_default      = REGMAP_ENDIAN_NATIVE,
  91         .val_format_endian_default      = REGMAP_ENDIAN_NATIVE,
  92 };
  93
  94 struct regmap *__regmap_init_spmi_base(struct spmi_device *sdev,
  95                                        const struct regmap_config *config,
  96                                        struct lock_class_key *lock_key,
  97                                        const char *lock_name)
  98 {
  99         return __regmap_init(&sdev->dev, &regmap_spmi_base, sdev, config,
 100                              lock_key, lock_name);
 101 }
 102 EXPORT_SYMBOL_GPL(__regmap_init_spmi_base);
 103
 104 struct regmap *__devm_regmap_init_spmi_base(struct spmi_device *sdev,
 105                                             const struct regmap_config *config,
 106                                             struct lock_class_key *lock_key,
 107                                             const char *lock_name)
 108 {
 109         return __devm_regmap_init(&sdev->dev, &regmap_spmi_base, sdev, config,
 110                                   lock_key, lock_name);
 111 }
 112 EXPORT_SYMBOL_GPL(__devm_regmap_init_spmi_base);
 113
 114 static int regmap_spmi_ext_read(void *context,
 115                                 const void *reg, size_t reg_size,
 116                                 void *val, size_t val_size)
 117 {
 118         int err = 0;
 119         size_t len;
 120         u16 addr;
 121
 122         BUG_ON(reg_size != 2);
 123
 124         addr = *(u16 *)reg;
 125
 126         /*
 127          * Split accesses into two to take advantage of the more
 128          * bandwidth-efficient 'Extended Register Read' command when possible
 129          */
 130         while (addr <= 0xFF && val_size) {
 131                 len = min_t(size_t, val_size, 16);
 132
 133                 err = spmi_ext_register_read(context, addr, val, len);
 134                 if (err)
 135                         goto err_out;
 136
 137                 addr += len;
 138                 val += len;
 139                 val_size -= len;
 140         }
 141
 142         while (val_size) {
 143                 len = min_t(size_t, val_size, 8);
 144
 145                 err = spmi_ext_register_readl(context, addr, val, val_size);
 146                 if (err)
 147                         goto err_out;
 148
 149                 addr += len;
 150                 val += len;
 151                 val_size -= len;
 152         }
 153
 154 err_out:
 155         return err;
 156 }
 157
 158 static int regmap_spmi_ext_gather_write(void *context,
 159                                         const void *reg, size_t reg_size,
 160                                         const void *val, size_t val_size)
 161 {
 162         int err = 0;
 163         size_t len;
 164         u16 addr;
 165
 166         BUG_ON(reg_size != 2);
 167
 168         addr = *(u16 *)reg;
 169
 170         while (addr <= 0xFF && val_size) {
 171                 len = min_t(size_t, val_size, 16);
 172
 173                 err = spmi_ext_register_write(context, addr, val, len);
 174                 if (err)
 175                         goto err_out;
 176
 177                 addr += len;
 178                 val += len;
 179                 val_size -= len;
 180         }
 181
 182         while (val_size) {
 183                 len = min_t(size_t, val_size, 8);
 184
 185                 err = spmi_ext_register_writel(context, addr, val, len);
 186                 if (err)
 187                         goto err_out;
 188
 189                 addr += len;
 190                 val += len;
 191                 val_size -= len;
 192         }
 193
 194 err_out:
 195         return err;
 196 }
 197
 198 static int regmap_spmi_ext_write(void *context, const void *data,
 199                                  size_t count)
 200 {
 201         BUG_ON(count < 2);
 202         return regmap_spmi_ext_gather_write(context, data, 2, data + 2,
 203                                             count - 2);
 204 }
 205
 206 static struct regmap_bus regmap_spmi_ext = {
 207         .read                           = regmap_spmi_ext_read,
 208         .write                          = regmap_spmi_ext_write,
 209         .gather_write                   = regmap_spmi_ext_gather_write,
 210         .reg_format_endian_default      = REGMAP_ENDIAN_NATIVE,
 211         .val_format_endian_default      = REGMAP_ENDIAN_NATIVE,
 212 };
 213
 214 struct regmap *__regmap_init_spmi_ext(struct spmi_device *sdev,
 215                                       const struct regmap_config *config,
 216                                       struct lock_class_key *lock_key,
 217                                       const char *lock_name)
 218 {
 219         return __regmap_init(&sdev->dev, &regmap_spmi_ext, sdev, config,
 220                              lock_key, lock_name);
 221 }
 222 EXPORT_SYMBOL_GPL(__regmap_init_spmi_ext);
 223
 224 struct regmap *__devm_regmap_init_spmi_ext(struct spmi_device *sdev,
 225                                            const struct regmap_config *config,
 226                                            struct lock_class_key *lock_key,
 227                                            const char *lock_name)
 228 {
 229         return __devm_regmap_init(&sdev->dev, &regmap_spmi_ext, sdev, config,
 230                                   lock_key, lock_name);
 231 }
 232 EXPORT_SYMBOL_GPL(__devm_regmap_init_spmi_ext);
 233
 234 MODULE_LICENSE("GPL");