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_GPL(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");
221