media/dvb-frontends/lnbh29.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 //
0003 // Driver for LNB supply and control IC STMicroelectronics LNBH29
0004 //
0005 // Copyright (c) 2018 Socionext Inc.
0006
0007 #include <linux/module.h>
0008 #include <linux/init.h>
0009 #include <linux/slab.h>
0010
0011 #include <media/dvb_frontend.h>
0012 #include "lnbh29.h"
0013
0014 /**
0015  * struct lnbh29_priv - LNBH29 driver private data
0016  * @i2c:         Pointer to the I2C adapter structure
0017  * @i2c_address: I2C address of LNBH29 chip
0018  * @config:      Registers configuration
0019  *               offset 0: 1st register address, always 0x01 (DATA)
0020  *               offset 1: DATA register value
0021  */
0022 struct lnbh29_priv {
0023     struct i2c_adapter *i2c;
0024     u8 i2c_address;
0025     u8 config[2];
0026 };
0027
0028 #define LNBH29_STATUS_OLF     BIT(0)
0029 #define LNBH29_STATUS_OTF     BIT(1)
0030 #define LNBH29_STATUS_VMON    BIT(2)
0031 #define LNBH29_STATUS_PNG     BIT(3)
0032 #define LNBH29_STATUS_PDO     BIT(4)
0033 #define LNBH29_VSEL_MASK      GENMASK(2, 0)
0034 #define LNBH29_VSEL_0         0x00
0035 /* Min: 13.188V, Typ: 13.667V, Max:14V */
0036 #define LNBH29_VSEL_13        0x03
0037 /* Min: 18.158V, Typ: 18.817V, Max:19.475V */
0038 #define LNBH29_VSEL_18        0x07
0039
0040 static int lnbh29_read_vmon(struct lnbh29_priv *priv)
0041 {
0042     u8 addr = 0x00;
0043     u8 status[2];
0044     int ret;
0045     struct i2c_msg msg[2] = {
0046         {
0047             .addr = priv->i2c_address,
0048             .flags = 0,
0049             .len = 1,
0050             .buf = &addr
0051         }, {
0052             .addr = priv->i2c_address,
0053             .flags = I2C_M_RD,
0054             .len = sizeof(status),
0055             .buf = status
0056         }
0057     };
0058
0059     ret = i2c_transfer(priv->i2c, msg, 2);
0060     if (ret >= 0 && ret != 2)
0061         ret = -EIO;
0062     if (ret < 0) {
0063         dev_dbg(&priv->i2c->dev, "LNBH29 I2C transfer failed (%d)\n",
0064             ret);
0065         return ret;
0066     }
0067
0068     if (status[0] & (LNBH29_STATUS_OLF | LNBH29_STATUS_VMON)) {
0069         dev_err(&priv->i2c->dev,
0070             "LNBH29 voltage in failure state, status reg 0x%x\n",
0071             status[0]);
0072         return -EIO;
0073     }
0074
0075     return 0;
0076 }
0077
0078 static int lnbh29_set_voltage(struct dvb_frontend *fe,
0079                   enum fe_sec_voltage voltage)
0080 {
0081     struct lnbh29_priv *priv = fe->sec_priv;
0082     u8 data_reg;
0083     int ret;
0084     struct i2c_msg msg = {
0085         .addr = priv->i2c_address,
0086         .flags = 0,
0087         .len = sizeof(priv->config),
0088         .buf = priv->config
0089     };
0090
0091     switch (voltage) {
0092     case SEC_VOLTAGE_OFF:
0093         data_reg = LNBH29_VSEL_0;
0094         break;
0095     case SEC_VOLTAGE_13:
0096         data_reg = LNBH29_VSEL_13;
0097         break;
0098     case SEC_VOLTAGE_18:
0099         data_reg = LNBH29_VSEL_18;
0100         break;
0101     default:
0102         return -EINVAL;
0103     }
0104     priv->config[1] &= ~LNBH29_VSEL_MASK;
0105     priv->config[1] |= data_reg;
0106
0107     ret = i2c_transfer(priv->i2c, &msg, 1);
0108     if (ret >= 0 && ret != 1)
0109         ret = -EIO;
0110     if (ret < 0) {
0111         dev_err(&priv->i2c->dev, "LNBH29 I2C transfer error (%d)\n",
0112             ret);
0113         return ret;
0114     }
0115
0116     /* Soft-start time (Vout 0V to 18V) is Typ. 6ms. */
0117     usleep_range(6000, 20000);
0118
0119     if (voltage == SEC_VOLTAGE_OFF)
0120         return 0;
0121
0122     return lnbh29_read_vmon(priv);
0123 }
0124
0125 static void lnbh29_release(struct dvb_frontend *fe)
0126 {
0127     lnbh29_set_voltage(fe, SEC_VOLTAGE_OFF);
0128     kfree(fe->sec_priv);
0129     fe->sec_priv = NULL;
0130 }
0131
0132 struct dvb_frontend *lnbh29_attach(struct dvb_frontend *fe,
0133                    struct lnbh29_config *cfg,
0134                    struct i2c_adapter *i2c)
0135 {
0136     struct lnbh29_priv *priv;
0137
0138     priv = kzalloc(sizeof(*priv), GFP_KERNEL);
0139     if (!priv)
0140         return NULL;
0141
0142     priv->i2c_address = (cfg->i2c_address >> 1);
0143     priv->i2c = i2c;
0144     priv->config[0] = 0x01;
0145     priv->config[1] = cfg->data_config;
0146     fe->sec_priv = priv;
0147
0148     if (lnbh29_set_voltage(fe, SEC_VOLTAGE_OFF)) {
0149         dev_err(&i2c->dev, "no LNBH29 found at I2C addr 0x%02x\n",
0150             priv->i2c_address);
0151         kfree(priv);
0152         fe->sec_priv = NULL;
0153         return NULL;
0154     }
0155
0156     fe->ops.release_sec = lnbh29_release;
0157     fe->ops.set_voltage = lnbh29_set_voltage;
0158
0159     dev_info(&i2c->dev, "LNBH29 attached at I2C addr 0x%02x\n",
0160          priv->i2c_address);
0161
0162     return fe;
0163 }
0164 EXPORT_SYMBOL(lnbh29_attach);
0165
0166 MODULE_AUTHOR("Katsuhiro Suzuki <suzuki.katsuhiro@socionext.com>");
0167 MODULE_DESCRIPTION("STMicroelectronics LNBH29 driver");
0168 MODULE_LICENSE("GPL v2");