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
lnbh29_read_vmon(struct lnbh29_priv * priv)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
lnbh29_set_voltage(struct dvb_frontend * fe,enum fe_sec_voltage voltage)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
lnbh29_release(struct dvb_frontend * fe)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
lnbh29_attach(struct dvb_frontend * fe,struct lnbh29_config * cfg,struct i2c_adapter * i2c)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");
169