drivers/media/dvb-frontends/lnbh29.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Driver for LNB supply and control IC STMicroelectronics LNBH29
   4 //
   5 // Copyright (c) 2018 Socionext Inc.
   6
   7 #include <linux/module.h>
   8 #include <linux/init.h>
   9 #include <linux/slab.h>
  10
  11 #include <media/dvb_frontend.h>
  12 #include "lnbh29.h"
  13
  14 /**
  15  * struct lnbh29_priv - LNBH29 driver private data
  16  * @i2c:         Pointer to the I2C adapter structure
  17  * @i2c_address: I2C address of LNBH29 chip
  18  * @config:      Registers configuration
  19  *               offset 0: 1st register address, always 0x01 (DATA)
  20  *               offset 1: DATA register value
  21  */
  22 struct lnbh29_priv {
  23         struct i2c_adapter *i2c;
  24         u8 i2c_address;
  25         u8 config[2];
  26 };
  27
  28 #define LNBH29_STATUS_OLF     BIT(0)
  29 #define LNBH29_STATUS_OTF     BIT(1)
  30 #define LNBH29_STATUS_VMON    BIT(2)
  31 #define LNBH29_STATUS_PNG     BIT(3)
  32 #define LNBH29_STATUS_PDO     BIT(4)
  33 #define LNBH29_VSEL_MASK      GENMASK(2, 0)
  34 #define LNBH29_VSEL_0         0x00
  35 /* Min: 13.188V, Typ: 13.667V, Max:14V */
  36 #define LNBH29_VSEL_13        0x03
  37 /* Min: 18.158V, Typ: 18.817V, Max:19.475V */
  38 #define LNBH29_VSEL_18        0x07
  39
  40 static int lnbh29_read_vmon(struct lnbh29_priv *priv)
  41 {
  42         u8 addr = 0x00;
  43         u8 status[2];
  44         int ret;
  45         struct i2c_msg msg[2] = {
  46                 {
  47                         .addr = priv->i2c_address,
  48                         .flags = 0,
  49                         .len = 1,
  50                         .buf = &addr
  51                 }, {
  52                         .addr = priv->i2c_address,
  53                         .flags = I2C_M_RD,
  54                         .len = sizeof(status),
  55                         .buf = status
  56                 }
  57         };
  58
  59         ret = i2c_transfer(priv->i2c, msg, 2);
  60         if (ret >= 0 && ret != 2)
  61                 ret = -EIO;
  62         if (ret < 0) {
  63                 dev_dbg(&priv->i2c->dev, "LNBH29 I2C transfer failed (%d)\n",
  64                         ret);
  65                 return ret;
  66         }
  67
  68         if (status[0] & (LNBH29_STATUS_OLF | LNBH29_STATUS_VMON)) {
  69                 dev_err(&priv->i2c->dev,
  70                         "LNBH29 voltage in failure state, status reg 0x%x\n",
  71                         status[0]);
  72                 return -EIO;
  73         }
  74
  75         return 0;
  76 }
  77
  78 static int lnbh29_set_voltage(struct dvb_frontend *fe,
  79                               enum fe_sec_voltage voltage)
  80 {
  81         struct lnbh29_priv *priv = fe->sec_priv;
  82         u8 data_reg;
  83         int ret;
  84         struct i2c_msg msg = {
  85                 .addr = priv->i2c_address,
  86                 .flags = 0,
  87                 .len = sizeof(priv->config),
  88                 .buf = priv->config
  89         };
  90
  91         switch (voltage) {
  92         case SEC_VOLTAGE_OFF:
  93                 data_reg = LNBH29_VSEL_0;
  94                 break;
  95         case SEC_VOLTAGE_13:
  96                 data_reg = LNBH29_VSEL_13;
  97                 break;
  98         case SEC_VOLTAGE_18:
  99                 data_reg = LNBH29_VSEL_18;
 100                 break;
 101         default:
 102                 return -EINVAL;
 103         }
 104         priv->config[1] &= ~LNBH29_VSEL_MASK;
 105         priv->config[1] |= data_reg;
 106
 107         ret = i2c_transfer(priv->i2c, &msg, 1);
 108         if (ret >= 0 && ret != 1)
 109                 ret = -EIO;
 110         if (ret < 0) {
 111                 dev_err(&priv->i2c->dev, "LNBH29 I2C transfer error (%d)\n",
 112                         ret);
 113                 return ret;
 114         }
 115
 116         /* Soft-start time (Vout 0V to 18V) is Typ. 6ms. */
 117         usleep_range(6000, 20000);
 118
 119         if (voltage == SEC_VOLTAGE_OFF)
 120                 return 0;
 121
 122         return lnbh29_read_vmon(priv);
 123 }
 124
 125 static void lnbh29_release(struct dvb_frontend *fe)
 126 {
 127         lnbh29_set_voltage(fe, SEC_VOLTAGE_OFF);
 128         kfree(fe->sec_priv);
 129         fe->sec_priv = NULL;
 130 }
 131
 132 struct dvb_frontend *lnbh29_attach(struct dvb_frontend *fe,
 133                                    struct lnbh29_config *cfg,
 134                                    struct i2c_adapter *i2c)
 135 {
 136         struct lnbh29_priv *priv;
 137
 138         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 139         if (!priv)
 140                 return NULL;
 141
 142         priv->i2c_address = (cfg->i2c_address >> 1);
 143         priv->i2c = i2c;
 144         priv->config[0] = 0x01;
 145         priv->config[1] = cfg->data_config;
 146         fe->sec_priv = priv;
 147
 148         if (lnbh29_set_voltage(fe, SEC_VOLTAGE_OFF)) {
 149                 dev_err(&i2c->dev, "no LNBH29 found at I2C addr 0x%02x\n",
 150                         priv->i2c_address);
 151                 kfree(priv);
 152                 fe->sec_priv = NULL;
 153                 return NULL;
 154         }
 155
 156         fe->ops.release_sec = lnbh29_release;
 157         fe->ops.set_voltage = lnbh29_set_voltage;
 158
 159         dev_info(&i2c->dev, "LNBH29 attached at I2C addr 0x%02x\n",
 160                  priv->i2c_address);
 161
 162         return fe;
 163 }
 164 EXPORT_SYMBOL(lnbh29_attach);
 165
 166 MODULE_AUTHOR("Katsuhiro Suzuki <suzuki.katsuhiro@socionext.com>");
 167 MODULE_DESCRIPTION("STMicroelectronics LNBH29 driver");
 168 MODULE_LICENSE("GPL v2");