drivers/media/dvb-frontends/isl6421.c

   1 /*
   2  * isl6421.h - driver for lnb supply and control ic ISL6421
   3  *
   4  * Copyright (C) 2006 Andrew de Quincey
   5  * Copyright (C) 2006 Oliver Endriss
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version 2
  10  * of the License, or (at your option) any later version.
  11  *
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * To obtain the license, point your browser to
  19  * http://www.gnu.org/copyleft/gpl.html
  20  *
  21  *
  22  * the project's page is at https://linuxtv.org
  23  */
  24 #include <linux/delay.h>
  25 #include <linux/errno.h>
  26 #include <linux/init.h>
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/string.h>
  30 #include <linux/slab.h>
  31
  32 #include <media/dvb_frontend.h>
  33 #include "isl6421.h"
  34
  35 struct isl6421 {
  36         u8                      config;
  37         u8                      override_or;
  38         u8                      override_and;
  39         struct i2c_adapter      *i2c;
  40         u8                      i2c_addr;
  41         bool                    is_off;
  42 };
  43
  44 static int isl6421_set_voltage(struct dvb_frontend *fe,
  45                                enum fe_sec_voltage voltage)
  46 {
  47         int ret;
  48         u8 buf;
  49         bool is_off;
  50         struct isl6421 *isl6421 = (struct isl6421 *) fe->sec_priv;
  51         struct i2c_msg msg[2] = {
  52                 {
  53                   .addr = isl6421->i2c_addr,
  54                   .flags = 0,
  55                   .buf = &isl6421->config,
  56                   .len = 1,
  57                 }, {
  58                   .addr = isl6421->i2c_addr,
  59                   .flags = I2C_M_RD,
  60                   .buf = &buf,
  61                   .len = 1,
  62                 }
  63
  64         };
  65
  66         isl6421->config &= ~(ISL6421_VSEL1 | ISL6421_EN1);
  67
  68         switch(voltage) {
  69         case SEC_VOLTAGE_OFF:
  70                 is_off = true;
  71                 break;
  72         case SEC_VOLTAGE_13:
  73                 is_off = false;
  74                 isl6421->config |= ISL6421_EN1;
  75                 break;
  76         case SEC_VOLTAGE_18:
  77                 is_off = false;
  78                 isl6421->config |= (ISL6421_EN1 | ISL6421_VSEL1);
  79                 break;
  80         default:
  81                 return -EINVAL;
  82         }
  83
  84         /*
  85          * If LNBf were not powered on, disable dynamic current limit, as,
  86          * according with datasheet, highly capacitive load on the output may
  87          * cause a difficult start-up.
  88          */
  89         if (isl6421->is_off && !is_off)
  90                 isl6421->config |= ISL6421_DCL;
  91
  92         isl6421->config |= isl6421->override_or;
  93         isl6421->config &= isl6421->override_and;
  94
  95         ret = i2c_transfer(isl6421->i2c, msg, 2);
  96         if (ret < 0)
  97                 return ret;
  98         if (ret != 2)
  99                 return -EIO;
 100
 101         /* Store off status now incase future commands fail */
 102         isl6421->is_off = is_off;
 103
 104         /* On overflow, the device will try again after 900 ms (typically) */
 105         if (!is_off && (buf & ISL6421_OLF1))
 106                 msleep(1000);
 107
 108         /* Re-enable dynamic current limit */
 109         if ((isl6421->config & ISL6421_DCL) &&
 110             !(isl6421->override_or & ISL6421_DCL)) {
 111                 isl6421->config &= ~ISL6421_DCL;
 112
 113                 ret = i2c_transfer(isl6421->i2c, msg, 2);
 114                 if (ret < 0)
 115                         return ret;
 116                 if (ret != 2)
 117                         return -EIO;
 118         }
 119
 120         /* Check if overload flag is active. If so, disable power */
 121         if (!is_off && (buf & ISL6421_OLF1)) {
 122                 isl6421->config &= ~(ISL6421_VSEL1 | ISL6421_EN1);
 123                 ret = i2c_transfer(isl6421->i2c, msg, 1);
 124                 if (ret < 0)
 125                         return ret;
 126                 if (ret != 1)
 127                         return -EIO;
 128                 isl6421->is_off = true;
 129
 130                 dev_warn(&isl6421->i2c->dev,
 131                          "Overload current detected. disabling LNBf power\n");
 132                 return -EINVAL;
 133         }
 134
 135         return 0;
 136 }
 137
 138 static int isl6421_enable_high_lnb_voltage(struct dvb_frontend *fe, long arg)
 139 {
 140         struct isl6421 *isl6421 = (struct isl6421 *) fe->sec_priv;
 141         struct i2c_msg msg = {  .addr = isl6421->i2c_addr, .flags = 0,
 142                                 .buf = &isl6421->config,
 143                                 .len = sizeof(isl6421->config) };
 144
 145         if (arg)
 146                 isl6421->config |= ISL6421_LLC1;
 147         else
 148                 isl6421->config &= ~ISL6421_LLC1;
 149
 150         isl6421->config |= isl6421->override_or;
 151         isl6421->config &= isl6421->override_and;
 152
 153         return (i2c_transfer(isl6421->i2c, &msg, 1) == 1) ? 0 : -EIO;
 154 }
 155
 156 static int isl6421_set_tone(struct dvb_frontend *fe,
 157                             enum fe_sec_tone_mode tone)
 158 {
 159         struct isl6421 *isl6421 = (struct isl6421 *) fe->sec_priv;
 160         struct i2c_msg msg = { .addr = isl6421->i2c_addr, .flags = 0,
 161                                .buf = &isl6421->config,
 162                                .len = sizeof(isl6421->config) };
 163
 164         switch (tone) {
 165         case SEC_TONE_ON:
 166                 isl6421->config |= ISL6421_ENT1;
 167                 break;
 168         case SEC_TONE_OFF:
 169                 isl6421->config &= ~ISL6421_ENT1;
 170                 break;
 171         default:
 172                 return -EINVAL;
 173         }
 174
 175         isl6421->config |= isl6421->override_or;
 176         isl6421->config &= isl6421->override_and;
 177
 178         return (i2c_transfer(isl6421->i2c, &msg, 1) == 1) ? 0 : -EIO;
 179 }
 180
 181 static void isl6421_release(struct dvb_frontend *fe)
 182 {
 183         /* power off */
 184         isl6421_set_voltage(fe, SEC_VOLTAGE_OFF);
 185
 186         /* free */
 187         kfree(fe->sec_priv);
 188         fe->sec_priv = NULL;
 189 }
 190
 191 struct dvb_frontend *isl6421_attach(struct dvb_frontend *fe, struct i2c_adapter *i2c, u8 i2c_addr,
 192                    u8 override_set, u8 override_clear, bool override_tone)
 193 {
 194         struct isl6421 *isl6421 = kmalloc(sizeof(struct isl6421), GFP_KERNEL);
 195         if (!isl6421)
 196                 return NULL;
 197
 198         /* default configuration */
 199         isl6421->config = ISL6421_ISEL1;
 200         isl6421->i2c = i2c;
 201         isl6421->i2c_addr = i2c_addr;
 202         fe->sec_priv = isl6421;
 203
 204         /* bits which should be forced to '1' */
 205         isl6421->override_or = override_set;
 206
 207         /* bits which should be forced to '0' */
 208         isl6421->override_and = ~override_clear;
 209
 210         /* detect if it is present or not */
 211         if (isl6421_set_voltage(fe, SEC_VOLTAGE_OFF)) {
 212                 kfree(isl6421);
 213                 fe->sec_priv = NULL;
 214                 return NULL;
 215         }
 216
 217         isl6421->is_off = true;
 218
 219         /* install release callback */
 220         fe->ops.release_sec = isl6421_release;
 221
 222         /* override frontend ops */
 223         fe->ops.set_voltage = isl6421_set_voltage;
 224         fe->ops.enable_high_lnb_voltage = isl6421_enable_high_lnb_voltage;
 225         if (override_tone)
 226                 fe->ops.set_tone = isl6421_set_tone;
 227
 228         return fe;
 229 }
 230 EXPORT_SYMBOL(isl6421_attach);
 231
 232 MODULE_DESCRIPTION("Driver for lnb supply and control ic isl6421");
 233 MODULE_AUTHOR("Andrew de Quincey & Oliver Endriss");
 234 MODULE_LICENSE("GPL");