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
21struct 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
30static 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
124static 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
142static 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
167static 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
177struct 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}
216EXPORT_SYMBOL_GPL(isl6421_attach);
217
218MODULE_DESCRIPTION("Driver for lnb supply and control ic isl6421");
219MODULE_AUTHOR("Andrew de Quincey & Oliver Endriss");
220MODULE_LICENSE("GPL");
221