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 */
 22struct 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
 40static 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
 78static 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
125static 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
132struct 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}
164EXPORT_SYMBOL(lnbh29_attach);
165
166MODULE_AUTHOR("Katsuhiro Suzuki <suzuki.katsuhiro@socionext.com>");
167MODULE_DESCRIPTION("STMicroelectronics LNBH29 driver");
168MODULE_LICENSE("GPL v2");