xref: /openbmc/linux/drivers/media/radio/tef6862.c (revision eb3fcf00)
1 /*
2  * tef6862.c Philips TEF6862 Car Radio Enhanced Selectivity Tuner
3  * Copyright (c) 2009 Intel Corporation
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17  */
18 
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/errno.h>
22 #include <linux/kernel.h>
23 #include <linux/interrupt.h>
24 #include <linux/i2c.h>
25 #include <linux/slab.h>
26 #include <media/v4l2-ioctl.h>
27 #include <media/v4l2-device.h>
28 
29 #define DRIVER_NAME "tef6862"
30 
31 #define FREQ_MUL 16000
32 
33 #define TEF6862_LO_FREQ (875U * FREQ_MUL / 10)
34 #define TEF6862_HI_FREQ (108U * FREQ_MUL)
35 
36 /* Write mode sub addresses */
37 #define WM_SUB_BANDWIDTH	0x0
38 #define WM_SUB_PLLM		0x1
39 #define WM_SUB_PLLL		0x2
40 #define WM_SUB_DAA		0x3
41 #define WM_SUB_AGC		0x4
42 #define WM_SUB_BAND		0x5
43 #define WM_SUB_CONTROL		0x6
44 #define WM_SUB_LEVEL		0x7
45 #define WM_SUB_IFCF		0x8
46 #define WM_SUB_IFCAP		0x9
47 #define WM_SUB_ACD		0xA
48 #define WM_SUB_TEST		0xF
49 
50 /* Different modes of the MSA register */
51 #define MSA_MODE_BUFFER		0x0
52 #define MSA_MODE_PRESET		0x1
53 #define MSA_MODE_SEARCH		0x2
54 #define MSA_MODE_AF_UPDATE	0x3
55 #define MSA_MODE_JUMP		0x4
56 #define MSA_MODE_CHECK		0x5
57 #define MSA_MODE_LOAD		0x6
58 #define MSA_MODE_END		0x7
59 #define MSA_MODE_SHIFT		5
60 
61 struct tef6862_state {
62 	struct v4l2_subdev sd;
63 	unsigned long freq;
64 };
65 
66 static inline struct tef6862_state *to_state(struct v4l2_subdev *sd)
67 {
68 	return container_of(sd, struct tef6862_state, sd);
69 }
70 
71 static u16 tef6862_sigstr(struct i2c_client *client)
72 {
73 	u8 buf[4];
74 	int err = i2c_master_recv(client, buf, sizeof(buf));
75 	if (err == sizeof(buf))
76 		return buf[3] << 8;
77 	return 0;
78 }
79 
80 static int tef6862_g_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *v)
81 {
82 	if (v->index > 0)
83 		return -EINVAL;
84 
85 	/* only support FM for now */
86 	strlcpy(v->name, "FM", sizeof(v->name));
87 	v->type = V4L2_TUNER_RADIO;
88 	v->rangelow = TEF6862_LO_FREQ;
89 	v->rangehigh = TEF6862_HI_FREQ;
90 	v->rxsubchans = V4L2_TUNER_SUB_MONO;
91 	v->capability = V4L2_TUNER_CAP_LOW;
92 	v->audmode = V4L2_TUNER_MODE_STEREO;
93 	v->signal = tef6862_sigstr(v4l2_get_subdevdata(sd));
94 
95 	return 0;
96 }
97 
98 static int tef6862_s_tuner(struct v4l2_subdev *sd, const struct v4l2_tuner *v)
99 {
100 	return v->index ? -EINVAL : 0;
101 }
102 
103 static int tef6862_s_frequency(struct v4l2_subdev *sd, const struct v4l2_frequency *f)
104 {
105 	struct tef6862_state *state = to_state(sd);
106 	struct i2c_client *client = v4l2_get_subdevdata(sd);
107 	unsigned freq = f->frequency;
108 	u16 pll;
109 	u8 i2cmsg[3];
110 	int err;
111 
112 	if (f->tuner != 0)
113 		return -EINVAL;
114 
115 	freq = clamp(freq, TEF6862_LO_FREQ, TEF6862_HI_FREQ);
116 	pll = 1964 + ((freq - TEF6862_LO_FREQ) * 20) / FREQ_MUL;
117 	i2cmsg[0] = (MSA_MODE_PRESET << MSA_MODE_SHIFT) | WM_SUB_PLLM;
118 	i2cmsg[1] = (pll >> 8) & 0xff;
119 	i2cmsg[2] = pll & 0xff;
120 
121 	err = i2c_master_send(client, i2cmsg, sizeof(i2cmsg));
122 	if (err != sizeof(i2cmsg))
123 		return err < 0 ? err : -EIO;
124 
125 	state->freq = freq;
126 	return 0;
127 }
128 
129 static int tef6862_g_frequency(struct v4l2_subdev *sd, struct v4l2_frequency *f)
130 {
131 	struct tef6862_state *state = to_state(sd);
132 
133 	if (f->tuner != 0)
134 		return -EINVAL;
135 	f->type = V4L2_TUNER_RADIO;
136 	f->frequency = state->freq;
137 	return 0;
138 }
139 
140 static const struct v4l2_subdev_tuner_ops tef6862_tuner_ops = {
141 	.g_tuner = tef6862_g_tuner,
142 	.s_tuner = tef6862_s_tuner,
143 	.s_frequency = tef6862_s_frequency,
144 	.g_frequency = tef6862_g_frequency,
145 };
146 
147 static const struct v4l2_subdev_ops tef6862_ops = {
148 	.tuner = &tef6862_tuner_ops,
149 };
150 
151 /*
152  * Generic i2c probe
153  * concerning the addresses: i2c wants 7 bit (without the r/w bit), so '>>1'
154  */
155 
156 static int tef6862_probe(struct i2c_client *client,
157 			 const struct i2c_device_id *id)
158 {
159 	struct tef6862_state *state;
160 	struct v4l2_subdev *sd;
161 
162 	/* Check if the adapter supports the needed features */
163 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
164 		return -EIO;
165 
166 	v4l_info(client, "chip found @ 0x%02x (%s)\n",
167 			client->addr << 1, client->adapter->name);
168 
169 	state = kzalloc(sizeof(struct tef6862_state), GFP_KERNEL);
170 	if (state == NULL)
171 		return -ENOMEM;
172 	state->freq = TEF6862_LO_FREQ;
173 
174 	sd = &state->sd;
175 	v4l2_i2c_subdev_init(sd, client, &tef6862_ops);
176 
177 	return 0;
178 }
179 
180 static int tef6862_remove(struct i2c_client *client)
181 {
182 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
183 
184 	v4l2_device_unregister_subdev(sd);
185 	kfree(to_state(sd));
186 	return 0;
187 }
188 
189 static const struct i2c_device_id tef6862_id[] = {
190 	{DRIVER_NAME, 0},
191 	{},
192 };
193 
194 MODULE_DEVICE_TABLE(i2c, tef6862_id);
195 
196 static struct i2c_driver tef6862_driver = {
197 	.driver = {
198 		.name	= DRIVER_NAME,
199 	},
200 	.probe		= tef6862_probe,
201 	.remove		= tef6862_remove,
202 	.id_table	= tef6862_id,
203 };
204 
205 module_i2c_driver(tef6862_driver);
206 
207 MODULE_DESCRIPTION("TEF6862 Car Radio Enhanced Selectivity Tuner");
208 MODULE_AUTHOR("Mocean Laboratories");
209 MODULE_LICENSE("GPL v2");
210