tda8261.c

  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
 17struct 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
 27static 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
 39static 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
 51static 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
 71static const u32 div_tab[] = { 2000, 1000,  500,  250,  125 }; /* kHz */
 72static const u8  ref_div[] = { 0x00, 0x01, 0x02, 0x05, 0x07 };
 73
 74static 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
 83static 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
143static 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
151static 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
165struct 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
186exit:
187	kfree(state);
188	return NULL;
189}
190
191EXPORT_SYMBOL_GPL(tda8261_attach);
192
193MODULE_AUTHOR("Manu Abraham");
194MODULE_DESCRIPTION("TDA8261 8PSK/QPSK Tuner");
195MODULE_LICENSE("GPL");