1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 	TDA8261 8PSK/QPSK tuner driver
4 	Copyright (C) Manu Abraham (abraham.manu@gmail.com)
5 
6 */
7 
8 
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/slab.h>
13 
14 #include <media/dvb_frontend.h>
15 #include "tda8261.h"
16 
17 struct tda8261_state {
18 	struct dvb_frontend		*fe;
19 	struct i2c_adapter		*i2c;
20 	const struct tda8261_config	*config;
21 
22 	/* state cache */
23 	u32 frequency;
24 	u32 bandwidth;
25 };
26 
27 static int tda8261_read(struct tda8261_state *state, u8 *buf)
28 {
29 	const struct tda8261_config *config = state->config;
30 	int err = 0;
31 	struct i2c_msg msg = { .addr	= config->addr, .flags = I2C_M_RD,.buf = buf,  .len = 1 };
32 
33 	if ((err = i2c_transfer(state->i2c, &msg, 1)) != 1)
34 		pr_err("%s: read error, err=%d\n", __func__, err);
35 
36 	return err;
37 }
38 
39 static int tda8261_write(struct tda8261_state *state, u8 *buf)
40 {
41 	const struct tda8261_config *config = state->config;
42 	int err = 0;
43 	struct i2c_msg msg = { .addr = config->addr, .flags = 0, .buf = buf, .len = 4 };
44 
45 	if ((err = i2c_transfer(state->i2c, &msg, 1)) != 1)
46 		pr_err("%s: write error, err=%d\n", __func__, err);
47 
48 	return err;
49 }
50 
51 static int tda8261_get_status(struct dvb_frontend *fe, u32 *status)
52 {
53 	struct tda8261_state *state = fe->tuner_priv;
54 	u8 result = 0;
55 	int err = 0;
56 
57 	*status = 0;
58 
59 	if ((err = tda8261_read(state, &result)) < 0) {
60 		pr_err("%s: I/O Error\n", __func__);
61 		return err;
62 	}
63 	if ((result >> 6) & 0x01) {
64 		pr_debug("%s: Tuner Phase Locked\n", __func__);
65 		*status = 1;
66 	}
67 
68 	return err;
69 }
70 
71 static const u32 div_tab[] = { 2000, 1000,  500,  250,  125 }; /* kHz */
72 static const u8  ref_div[] = { 0x00, 0x01, 0x02, 0x05, 0x07 };
73 
74 static int tda8261_get_frequency(struct dvb_frontend *fe, u32 *frequency)
75 {
76 	struct tda8261_state *state = fe->tuner_priv;
77 
78 	*frequency = state->frequency;
79 
80 	return 0;
81 }
82 
83 static int tda8261_set_params(struct dvb_frontend *fe)
84 {
85 	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
86 	struct tda8261_state *state = fe->tuner_priv;
87 	const struct tda8261_config *config = state->config;
88 	u32 frequency, N, status = 0;
89 	u8 buf[4];
90 	int err = 0;
91 
92 	/*
93 	 * N = Max VCO Frequency / Channel Spacing
94 	 * Max VCO Frequency = VCO frequency + (channel spacing - 1)
95 	 * (to account for half channel spacing on either side)
96 	 */
97 	frequency = c->frequency;
98 	if ((frequency < 950000) || (frequency > 2150000)) {
99 		pr_warn("%s: Frequency beyond limits, frequency=%d\n",
100 			__func__, frequency);
101 		return -EINVAL;
102 	}
103 	N = (frequency + (div_tab[config->step_size] - 1)) / div_tab[config->step_size];
104 	pr_debug("%s: Step size=%d, Divider=%d, PG=0x%02x (%d)\n",
105 		__func__, config->step_size, div_tab[config->step_size], N, N);
106 
107 	buf[0] = (N >> 8) & 0xff;
108 	buf[1] = N & 0xff;
109 	buf[2] = (0x01 << 7) | ((ref_div[config->step_size] & 0x07) << 1);
110 
111 	if (frequency < 1450000)
112 		buf[3] = 0x00;
113 	else if (frequency < 2000000)
114 		buf[3] = 0x40;
115 	else if (frequency < 2150000)
116 		buf[3] = 0x80;
117 
118 	/* Set params */
119 	err = tda8261_write(state, buf);
120 	if (err < 0) {
121 		pr_err("%s: I/O Error\n", __func__);
122 		return err;
123 	}
124 	/* sleep for some time */
125 	pr_debug("%s: Waiting to Phase LOCK\n", __func__);
126 	msleep(20);
127 	/* check status */
128 	if ((err = tda8261_get_status(fe, &status)) < 0) {
129 		pr_err("%s: I/O Error\n", __func__);
130 		return err;
131 	}
132 	if (status == 1) {
133 		pr_debug("%s: Tuner Phase locked: status=%d\n", __func__,
134 			 status);
135 		state->frequency = frequency; /* cache successful state */
136 	} else {
137 		pr_debug("%s: No Phase lock: status=%d\n", __func__, status);
138 	}
139 
140 	return 0;
141 }
142 
143 static void tda8261_release(struct dvb_frontend *fe)
144 {
145 	struct tda8261_state *state = fe->tuner_priv;
146 
147 	fe->tuner_priv = NULL;
148 	kfree(state);
149 }
150 
151 static const struct dvb_tuner_ops tda8261_ops = {
152 
153 	.info = {
154 		.name		   = "TDA8261",
155 		.frequency_min_hz  =  950 * MHz,
156 		.frequency_max_hz  = 2150 * MHz,
157 	},
158 
159 	.set_params	= tda8261_set_params,
160 	.get_frequency	= tda8261_get_frequency,
161 	.get_status	= tda8261_get_status,
162 	.release	= tda8261_release
163 };
164 
165 struct dvb_frontend *tda8261_attach(struct dvb_frontend *fe,
166 				    const struct tda8261_config *config,
167 				    struct i2c_adapter *i2c)
168 {
169 	struct tda8261_state *state = NULL;
170 
171 	if ((state = kzalloc(sizeof (struct tda8261_state), GFP_KERNEL)) == NULL)
172 		goto exit;
173 
174 	state->config		= config;
175 	state->i2c		= i2c;
176 	state->fe		= fe;
177 	fe->tuner_priv		= state;
178 	fe->ops.tuner_ops	= tda8261_ops;
179 
180 	fe->ops.tuner_ops.info.frequency_step_hz = div_tab[config->step_size] * kHz;
181 
182 	pr_info("%s: Attaching TDA8261 8PSK/QPSK tuner\n", __func__);
183 
184 	return fe;
185 
186 exit:
187 	kfree(state);
188 	return NULL;
189 }
190 
191 EXPORT_SYMBOL(tda8261_attach);
192 
193 MODULE_AUTHOR("Manu Abraham");
194 MODULE_DESCRIPTION("TDA8261 8PSK/QPSK Tuner");
195 MODULE_LICENSE("GPL");
196