drivers/media/dvb-frontends/a8293.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Allegro A8293 SEC driver
   4  *
   5  * Copyright (C) 2011 Antti Palosaari <crope@iki.fi>
   6  */
   7
   8 #include "a8293.h"
   9
  10 #define A8293_FLAG_ODT                  0x10
  11
  12 struct a8293_dev {
  13         struct i2c_client *client;
  14         u8 reg[2];
  15         int volt_slew_nanos_per_mv;
  16 };
  17
  18 /*
  19  * When increasing voltage, do so in minimal steps over time, minimizing
  20  * risk of vIN undervoltage.
  21  */
  22
  23 static int a8293_set_voltage_slew(struct a8293_dev *dev,
  24                                   struct i2c_client *client,
  25                                   enum fe_sec_voltage fe_sec_voltage,
  26                                   int min_nanos_per_mv)
  27 {
  28         int ret;
  29         u8 reg0, reg1;
  30         int new_volt_idx;
  31         const int idx_to_mv[] = {
  32                 0,    12709, 13042, 13375, 14042, 15042, 18042, 18709, 19042
  33         };
  34         const u8 idx_to_reg[] = {
  35                 0x00, 0x20,  0x21,  0x22,  0x24,  0x27,  0x28,  0x2A,  0x2B
  36         };
  37         int this_volt_idx;
  38         u8 status;
  39         int prev_volt_idx;
  40
  41         dev_dbg(&client->dev, "set_voltage_slew fe_sec_voltage=%d\n",
  42                 fe_sec_voltage);
  43
  44         /* Read status register to clear any stale faults. */
  45         ret = i2c_master_recv(client, &status, 1);
  46         if (ret < 0)
  47                 goto err;
  48
  49         /* Determine previous voltage */
  50         switch (dev->reg[0] & 0x2F) {
  51         case 0x00:
  52                 prev_volt_idx = 0;
  53                 break;
  54         case 0x20:
  55                 prev_volt_idx = 1;
  56                 break;
  57         case 0x21:
  58                 prev_volt_idx = 2;
  59                 break;
  60         case 0x22:
  61                 prev_volt_idx = 3;
  62                 break;
  63         case 0x24:
  64                 prev_volt_idx = 4;
  65                 break;
  66         case 0x27:
  67                 prev_volt_idx = 5;
  68                 break;
  69         case 0x28:
  70                 prev_volt_idx = 6;
  71                 break;
  72         case 0x2A:
  73                 prev_volt_idx = 7;
  74                 break;
  75         case 0x2B:
  76                 prev_volt_idx = 8;
  77                 break;
  78         default:
  79                 prev_volt_idx = 0;
  80         }
  81
  82         /* Determine new voltage */
  83         switch (fe_sec_voltage) {
  84         case SEC_VOLTAGE_OFF:
  85                 new_volt_idx = 0;
  86                 break;
  87         case SEC_VOLTAGE_13:
  88                 new_volt_idx = 2;
  89                 break;
  90         case SEC_VOLTAGE_18:
  91                 new_volt_idx = 6;
  92                 break;
  93         default:
  94                 ret = -EINVAL;
  95                 goto err;
  96         }
  97
  98         /* Slew to new voltage if new voltage is greater than current voltage */
  99         this_volt_idx = prev_volt_idx;
 100         if (this_volt_idx < new_volt_idx) {
 101                 while (this_volt_idx < new_volt_idx) {
 102                         int delta_mv = idx_to_mv[this_volt_idx+1] - idx_to_mv[this_volt_idx];
 103                         int min_wait_time = delta_mv * min_nanos_per_mv;
 104
 105                         reg0 = idx_to_reg[this_volt_idx+1];
 106                         reg0 |= A8293_FLAG_ODT;
 107
 108                         ret = i2c_master_send(client, &reg0, 1);
 109                         if (ret < 0)
 110                                 goto err;
 111                         dev->reg[0] = reg0;
 112                         this_volt_idx++;
 113                         usleep_range(min_wait_time, min_wait_time * 2);
 114                 }
 115         } else { /* Else just set the voltage */
 116                 reg0 = idx_to_reg[new_volt_idx];
 117                 reg0 |= A8293_FLAG_ODT;
 118                 ret = i2c_master_send(client, &reg0, 1);
 119                 if (ret < 0)
 120                         goto err;
 121                 dev->reg[0] = reg0;
 122         }
 123
 124         /* TMODE=0, TGATE=1 */
 125         reg1 = 0x82;
 126         if (reg1 != dev->reg[1]) {
 127                 ret = i2c_master_send(client, &reg1, 1);
 128                 if (ret < 0)
 129                         goto err;
 130                 dev->reg[1] = reg1;
 131         }
 132
 133         usleep_range(1500, 5000);
 134
 135         return 0;
 136 err:
 137         dev_dbg(&client->dev, "failed=%d\n", ret);
 138         return ret;
 139 }
 140
 141
 142 static int a8293_set_voltage_noslew(struct dvb_frontend *fe,
 143                                     enum fe_sec_voltage fe_sec_voltage)
 144 {
 145         struct a8293_dev *dev = fe->sec_priv;
 146         struct i2c_client *client = dev->client;
 147         int ret;
 148         u8 reg0, reg1;
 149
 150         dev_dbg(&client->dev, "set_voltage_noslew fe_sec_voltage=%d\n",
 151                 fe_sec_voltage);
 152
 153         switch (fe_sec_voltage) {
 154         case SEC_VOLTAGE_OFF:
 155                 /* ENB=0 */
 156                 reg0 = 0x10;
 157                 break;
 158         case SEC_VOLTAGE_13:
 159                 /* VSEL0=1, VSEL1=0, VSEL2=0, VSEL3=0, ENB=1*/
 160                 reg0 = 0x31;
 161                 break;
 162         case SEC_VOLTAGE_18:
 163                 /* VSEL0=0, VSEL1=0, VSEL2=0, VSEL3=1, ENB=1*/
 164                 reg0 = 0x38;
 165                 break;
 166         default:
 167                 ret = -EINVAL;
 168                 goto err;
 169         }
 170         if (reg0 != dev->reg[0]) {
 171                 ret = i2c_master_send(client, &reg0, 1);
 172                 if (ret < 0)
 173                         goto err;
 174                 dev->reg[0] = reg0;
 175         }
 176
 177         /* TMODE=0, TGATE=1 */
 178         reg1 = 0x82;
 179         if (reg1 != dev->reg[1]) {
 180                 ret = i2c_master_send(client, &reg1, 1);
 181                 if (ret < 0)
 182                         goto err;
 183                 dev->reg[1] = reg1;
 184         }
 185
 186         usleep_range(1500, 50000);
 187         return 0;
 188 err:
 189         dev_dbg(&client->dev, "failed=%d\n", ret);
 190         return ret;
 191 }
 192
 193 static int a8293_set_voltage(struct dvb_frontend *fe,
 194                              enum fe_sec_voltage fe_sec_voltage)
 195 {
 196         struct a8293_dev *dev = fe->sec_priv;
 197         struct i2c_client *client = dev->client;
 198         int volt_slew_nanos_per_mv = dev->volt_slew_nanos_per_mv;
 199
 200         dev_dbg(&client->dev, "set_voltage volt_slew_nanos_per_mv=%d\n",
 201                 volt_slew_nanos_per_mv);
 202
 203         /* Use slew version if slew rate is set to a sane value */
 204         if (volt_slew_nanos_per_mv > 0 && volt_slew_nanos_per_mv < 1600)
 205                 a8293_set_voltage_slew(dev, client, fe_sec_voltage,
 206                                        volt_slew_nanos_per_mv);
 207         else
 208                 a8293_set_voltage_noslew(fe, fe_sec_voltage);
 209
 210         return 0;
 211 }
 212
 213 static int a8293_probe(struct i2c_client *client)
 214 {
 215         struct a8293_dev *dev;
 216         struct a8293_platform_data *pdata = client->dev.platform_data;
 217         struct dvb_frontend *fe = pdata->dvb_frontend;
 218         int ret;
 219         u8 buf[2];
 220
 221         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 222         if (!dev) {
 223                 ret = -ENOMEM;
 224                 goto err;
 225         }
 226
 227         dev->client = client;
 228         dev->volt_slew_nanos_per_mv = pdata->volt_slew_nanos_per_mv;
 229
 230         /* check if the SEC is there */
 231         ret = i2c_master_recv(client, buf, 2);
 232         if (ret < 0)
 233                 goto err_kfree;
 234
 235         /* override frontend ops */
 236         fe->ops.set_voltage = a8293_set_voltage;
 237         fe->sec_priv = dev;
 238         i2c_set_clientdata(client, dev);
 239
 240         dev_info(&client->dev, "Allegro A8293 SEC successfully attached\n");
 241         return 0;
 242 err_kfree:
 243         kfree(dev);
 244 err:
 245         dev_dbg(&client->dev, "failed=%d\n", ret);
 246         return ret;
 247 }
 248
 249 static void a8293_remove(struct i2c_client *client)
 250 {
 251         struct a8293_dev *dev = i2c_get_clientdata(client);
 252
 253         dev_dbg(&client->dev, "\n");
 254
 255         kfree(dev);
 256 }
 257
 258 static const struct i2c_device_id a8293_id_table[] = {
 259         {"a8293", 0},
 260         {}
 261 };
 262 MODULE_DEVICE_TABLE(i2c, a8293_id_table);
 263
 264 static struct i2c_driver a8293_driver = {
 265         .driver = {
 266                 .name   = "a8293",
 267                 .suppress_bind_attrs = true,
 268         },
 269         .probe          = a8293_probe,
 270         .remove         = a8293_remove,
 271         .id_table       = a8293_id_table,
 272 };
 273
 274 module_i2c_driver(a8293_driver);
 275
 276 MODULE_AUTHOR("Antti Palosaari <crope@iki.fi>");
 277 MODULE_DESCRIPTION("Allegro A8293 SEC driver");
 278 MODULE_LICENSE("GPL");