xref: /linux/drivers/media/radio/tef6862.c (revision b77e0ce62d63a761ffb7f7245a215a49f5921c2f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * tef6862.c Philips TEF6862 Car Radio Enhanced Selectivity Tuner
4  * Copyright (c) 2009 Intel Corporation
5  */
6 
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/errno.h>
10 #include <linux/kernel.h>
11 #include <linux/interrupt.h>
12 #include <linux/i2c.h>
13 #include <linux/slab.h>
14 #include <media/v4l2-ioctl.h>
15 #include <media/v4l2-device.h>
16 
17 #define DRIVER_NAME "tef6862"
18 
19 #define FREQ_MUL 16000
20 
21 #define TEF6862_LO_FREQ (875U * FREQ_MUL / 10)
22 #define TEF6862_HI_FREQ (108U * FREQ_MUL)
23 
24 /* Write mode sub addresses */
25 #define WM_SUB_BANDWIDTH	0x0
26 #define WM_SUB_PLLM		0x1
27 #define WM_SUB_PLLL		0x2
28 #define WM_SUB_DAA		0x3
29 #define WM_SUB_AGC		0x4
30 #define WM_SUB_BAND		0x5
31 #define WM_SUB_CONTROL		0x6
32 #define WM_SUB_LEVEL		0x7
33 #define WM_SUB_IFCF		0x8
34 #define WM_SUB_IFCAP		0x9
35 #define WM_SUB_ACD		0xA
36 #define WM_SUB_TEST		0xF
37 
38 /* Different modes of the MSA register */
39 #define MSA_MODE_BUFFER		0x0
40 #define MSA_MODE_PRESET		0x1
41 #define MSA_MODE_SEARCH		0x2
42 #define MSA_MODE_AF_UPDATE	0x3
43 #define MSA_MODE_JUMP		0x4
44 #define MSA_MODE_CHECK		0x5
45 #define MSA_MODE_LOAD		0x6
46 #define MSA_MODE_END		0x7
47 #define MSA_MODE_SHIFT		5
48 
49 struct tef6862_state {
50 	struct v4l2_subdev sd;
51 	unsigned long freq;
52 };
53 
54 static inline struct tef6862_state *to_state(struct v4l2_subdev *sd)
55 {
56 	return container_of(sd, struct tef6862_state, sd);
57 }
58 
59 static u16 tef6862_sigstr(struct i2c_client *client)
60 {
61 	u8 buf[4];
62 	int err = i2c_master_recv(client, buf, sizeof(buf));
63 	if (err == sizeof(buf))
64 		return buf[3] << 8;
65 	return 0;
66 }
67 
68 static int tef6862_g_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *v)
69 {
70 	if (v->index > 0)
71 		return -EINVAL;
72 
73 	/* only support FM for now */
74 	strscpy(v->name, "FM", sizeof(v->name));
75 	v->type = V4L2_TUNER_RADIO;
76 	v->rangelow = TEF6862_LO_FREQ;
77 	v->rangehigh = TEF6862_HI_FREQ;
78 	v->rxsubchans = V4L2_TUNER_SUB_MONO;
79 	v->capability = V4L2_TUNER_CAP_LOW;
80 	v->audmode = V4L2_TUNER_MODE_STEREO;
81 	v->signal = tef6862_sigstr(v4l2_get_subdevdata(sd));
82 
83 	return 0;
84 }
85 
86 static int tef6862_s_tuner(struct v4l2_subdev *sd, const struct v4l2_tuner *v)
87 {
88 	return v->index ? -EINVAL : 0;
89 }
90 
91 static int tef6862_s_frequency(struct v4l2_subdev *sd, const struct v4l2_frequency *f)
92 {
93 	struct tef6862_state *state = to_state(sd);
94 	struct i2c_client *client = v4l2_get_subdevdata(sd);
95 	unsigned freq = f->frequency;
96 	u16 pll;
97 	u8 i2cmsg[3];
98 	int err;
99 
100 	if (f->tuner != 0)
101 		return -EINVAL;
102 
103 	freq = clamp(freq, TEF6862_LO_FREQ, TEF6862_HI_FREQ);
104 	pll = 1964 + ((freq - TEF6862_LO_FREQ) * 20) / FREQ_MUL;
105 	i2cmsg[0] = (MSA_MODE_PRESET << MSA_MODE_SHIFT) | WM_SUB_PLLM;
106 	i2cmsg[1] = (pll >> 8) & 0xff;
107 	i2cmsg[2] = pll & 0xff;
108 
109 	err = i2c_master_send(client, i2cmsg, sizeof(i2cmsg));
110 	if (err != sizeof(i2cmsg))
111 		return err < 0 ? err : -EIO;
112 
113 	state->freq = freq;
114 	return 0;
115 }
116 
117 static int tef6862_g_frequency(struct v4l2_subdev *sd, struct v4l2_frequency *f)
118 {
119 	struct tef6862_state *state = to_state(sd);
120 
121 	if (f->tuner != 0)
122 		return -EINVAL;
123 	f->type = V4L2_TUNER_RADIO;
124 	f->frequency = state->freq;
125 	return 0;
126 }
127 
128 static const struct v4l2_subdev_tuner_ops tef6862_tuner_ops = {
129 	.g_tuner = tef6862_g_tuner,
130 	.s_tuner = tef6862_s_tuner,
131 	.s_frequency = tef6862_s_frequency,
132 	.g_frequency = tef6862_g_frequency,
133 };
134 
135 static const struct v4l2_subdev_ops tef6862_ops = {
136 	.tuner = &tef6862_tuner_ops,
137 };
138 
139 /*
140  * Generic i2c probe
141  * concerning the addresses: i2c wants 7 bit (without the r/w bit), so '>>1'
142  */
143 
144 static int tef6862_probe(struct i2c_client *client,
145 			 const struct i2c_device_id *id)
146 {
147 	struct tef6862_state *state;
148 	struct v4l2_subdev *sd;
149 
150 	/* Check if the adapter supports the needed features */
151 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
152 		return -EIO;
153 
154 	v4l_info(client, "chip found @ 0x%02x (%s)\n",
155 			client->addr << 1, client->adapter->name);
156 
157 	state = kzalloc(sizeof(struct tef6862_state), GFP_KERNEL);
158 	if (state == NULL)
159 		return -ENOMEM;
160 	state->freq = TEF6862_LO_FREQ;
161 
162 	sd = &state->sd;
163 	v4l2_i2c_subdev_init(sd, client, &tef6862_ops);
164 
165 	return 0;
166 }
167 
168 static int tef6862_remove(struct i2c_client *client)
169 {
170 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
171 
172 	v4l2_device_unregister_subdev(sd);
173 	kfree(to_state(sd));
174 	return 0;
175 }
176 
177 static const struct i2c_device_id tef6862_id[] = {
178 	{DRIVER_NAME, 0},
179 	{},
180 };
181 
182 MODULE_DEVICE_TABLE(i2c, tef6862_id);
183 
184 static struct i2c_driver tef6862_driver = {
185 	.driver = {
186 		.name	= DRIVER_NAME,
187 	},
188 	.probe		= tef6862_probe,
189 	.remove		= tef6862_remove,
190 	.id_table	= tef6862_id,
191 };
192 
193 module_i2c_driver(tef6862_driver);
194 
195 MODULE_DESCRIPTION("TEF6862 Car Radio Enhanced Selectivity Tuner");
196 MODULE_AUTHOR("Mocean Laboratories");
197 MODULE_LICENSE("GPL v2");
198