drivers/media/dvb-frontends/isl6421.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * isl6421.h - driver for lnb supply and control ic ISL6421
   4  *
   5  * Copyright (C) 2006 Andrew de Quincey
   6  * Copyright (C) 2006 Oliver Endriss
   7  *
   8  * the project's page is at https://linuxtv.org
   9  */
  10 #include <linux/delay.h>
  11 #include <linux/errno.h>
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/string.h>
  16 #include <linux/slab.h>
  17
  18 #include <media/dvb_frontend.h>
  19 #include "isl6421.h"
  20
  21 struct isl6421 {
  22         u8                      config;
  23         u8                      override_or;
  24         u8                      override_and;
  25         struct i2c_adapter      *i2c;
  26         u8                      i2c_addr;
  27         bool                    is_off;
  28 };
  29
  30 static int isl6421_set_voltage(struct dvb_frontend *fe,
  31                                enum fe_sec_voltage voltage)
  32 {
  33         int ret;
  34         u8 buf;
  35         bool is_off;
  36         struct isl6421 *isl6421 = (struct isl6421 *) fe->sec_priv;
  37         struct i2c_msg msg[2] = {
  38                 {
  39                   .addr = isl6421->i2c_addr,
  40                   .flags = 0,
  41                   .buf = &isl6421->config,
  42                   .len = 1,
  43                 }, {
  44                   .addr = isl6421->i2c_addr,
  45                   .flags = I2C_M_RD,
  46                   .buf = &buf,
  47                   .len = 1,
  48                 }
  49
  50         };
  51
  52         isl6421->config &= ~(ISL6421_VSEL1 | ISL6421_EN1);
  53
  54         switch(voltage) {
  55         case SEC_VOLTAGE_OFF:
  56                 is_off = true;
  57                 break;
  58         case SEC_VOLTAGE_13:
  59                 is_off = false;
  60                 isl6421->config |= ISL6421_EN1;
  61                 break;
  62         case SEC_VOLTAGE_18:
  63                 is_off = false;
  64                 isl6421->config |= (ISL6421_EN1 | ISL6421_VSEL1);
  65                 break;
  66         default:
  67                 return -EINVAL;
  68         }
  69
  70         /*
  71          * If LNBf were not powered on, disable dynamic current limit, as,
  72          * according with datasheet, highly capacitive load on the output may
  73          * cause a difficult start-up.
  74          */
  75         if (isl6421->is_off && !is_off)
  76                 isl6421->config |= ISL6421_DCL;
  77
  78         isl6421->config |= isl6421->override_or;
  79         isl6421->config &= isl6421->override_and;
  80
  81         ret = i2c_transfer(isl6421->i2c, msg, 2);
  82         if (ret < 0)
  83                 return ret;
  84         if (ret != 2)
  85                 return -EIO;
  86
  87         /* Store off status now in case future commands fail */
  88         isl6421->is_off = is_off;
  89
  90         /* On overflow, the device will try again after 900 ms (typically) */
  91         if (!is_off && (buf & ISL6421_OLF1))
  92                 msleep(1000);
  93
  94         /* Re-enable dynamic current limit */
  95         if ((isl6421->config & ISL6421_DCL) &&
  96             !(isl6421->override_or & ISL6421_DCL)) {
  97                 isl6421->config &= ~ISL6421_DCL;
  98
  99                 ret = i2c_transfer(isl6421->i2c, msg, 2);
 100                 if (ret < 0)
 101                         return ret;
 102                 if (ret != 2)
 103                         return -EIO;
 104         }
 105
 106         /* Check if overload flag is active. If so, disable power */
 107         if (!is_off && (buf & ISL6421_OLF1)) {
 108                 isl6421->config &= ~(ISL6421_VSEL1 | ISL6421_EN1);
 109                 ret = i2c_transfer(isl6421->i2c, msg, 1);
 110                 if (ret < 0)
 111                         return ret;
 112                 if (ret != 1)
 113                         return -EIO;
 114                 isl6421->is_off = true;
 115
 116                 dev_warn(&isl6421->i2c->dev,
 117                          "Overload current detected. disabling LNBf power\n");
 118                 return -EINVAL;
 119         }
 120
 121         return 0;
 122 }
 123
 124 static int isl6421_enable_high_lnb_voltage(struct dvb_frontend *fe, long arg)
 125 {
 126         struct isl6421 *isl6421 = (struct isl6421 *) fe->sec_priv;
 127         struct i2c_msg msg = {  .addr = isl6421->i2c_addr, .flags = 0,
 128                                 .buf = &isl6421->config,
 129                                 .len = sizeof(isl6421->config) };
 130
 131         if (arg)
 132                 isl6421->config |= ISL6421_LLC1;
 133         else
 134                 isl6421->config &= ~ISL6421_LLC1;
 135
 136         isl6421->config |= isl6421->override_or;
 137         isl6421->config &= isl6421->override_and;
 138
 139         return (i2c_transfer(isl6421->i2c, &msg, 1) == 1) ? 0 : -EIO;
 140 }
 141
 142 static int isl6421_set_tone(struct dvb_frontend *fe,
 143                             enum fe_sec_tone_mode tone)
 144 {
 145         struct isl6421 *isl6421 = (struct isl6421 *) fe->sec_priv;
 146         struct i2c_msg msg = { .addr = isl6421->i2c_addr, .flags = 0,
 147                                .buf = &isl6421->config,
 148                                .len = sizeof(isl6421->config) };
 149
 150         switch (tone) {
 151         case SEC_TONE_ON:
 152                 isl6421->config |= ISL6421_ENT1;
 153                 break;
 154         case SEC_TONE_OFF:
 155                 isl6421->config &= ~ISL6421_ENT1;
 156                 break;
 157         default:
 158                 return -EINVAL;
 159         }
 160
 161         isl6421->config |= isl6421->override_or;
 162         isl6421->config &= isl6421->override_and;
 163
 164         return (i2c_transfer(isl6421->i2c, &msg, 1) == 1) ? 0 : -EIO;
 165 }
 166
 167 static void isl6421_release(struct dvb_frontend *fe)
 168 {
 169         /* power off */
 170         isl6421_set_voltage(fe, SEC_VOLTAGE_OFF);
 171
 172         /* free */
 173         kfree(fe->sec_priv);
 174         fe->sec_priv = NULL;
 175 }
 176
 177 struct dvb_frontend *isl6421_attach(struct dvb_frontend *fe, struct i2c_adapter *i2c, u8 i2c_addr,
 178                    u8 override_set, u8 override_clear, bool override_tone)
 179 {
 180         struct isl6421 *isl6421 = kmalloc(sizeof(struct isl6421), GFP_KERNEL);
 181         if (!isl6421)
 182                 return NULL;
 183
 184         /* default configuration */
 185         isl6421->config = ISL6421_ISEL1;
 186         isl6421->i2c = i2c;
 187         isl6421->i2c_addr = i2c_addr;
 188         fe->sec_priv = isl6421;
 189
 190         /* bits which should be forced to '1' */
 191         isl6421->override_or = override_set;
 192
 193         /* bits which should be forced to '0' */
 194         isl6421->override_and = ~override_clear;
 195
 196         /* detect if it is present or not */
 197         if (isl6421_set_voltage(fe, SEC_VOLTAGE_OFF)) {
 198                 kfree(isl6421);
 199                 fe->sec_priv = NULL;
 200                 return NULL;
 201         }
 202
 203         isl6421->is_off = true;
 204
 205         /* install release callback */
 206         fe->ops.release_sec = isl6421_release;
 207
 208         /* override frontend ops */
 209         fe->ops.set_voltage = isl6421_set_voltage;
 210         fe->ops.enable_high_lnb_voltage = isl6421_enable_high_lnb_voltage;
 211         if (override_tone)
 212                 fe->ops.set_tone = isl6421_set_tone;
 213
 214         return fe;
 215 }
 216 EXPORT_SYMBOL(isl6421_attach);
 217
 218 MODULE_DESCRIPTION("Driver for lnb supply and control ic isl6421");
 219 MODULE_AUTHOR("Andrew de Quincey & Oliver Endriss");
 220 MODULE_LICENSE("GPL");