[media] mxl301rf: add driver for MaxLinear MxL301RF OFDM tuner

This patch adds driver for mxl301rf OFDM tuner chips.
It is used as an ISDB-T tuner in earthsoft pt3 cards.

Note that this driver does not initilize the chip,
because the initilization sequence / register setting is not disclosed.
Thus, the driver assumes that the chips are initilized externally
by its parent board driver before tuner_ops->init() are called,
like in PT3 driver where the bridge chip contains the init sequence
in its private memory and provides a command to trigger the sequence.

Signed-off-by: Akihiro Tsukada <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/tuners/Kconfig

···
 	default m if !MEDIA_SUBDRV_AUTOSELECT
 	help
 	  Rafael Micro R820T silicon tuner driver.
+
+config MEDIA_TUNER_MXL301RF
+	tristate "MaxLinear MxL301RF tuner"
+	depends on MEDIA_SUPPORT && I2C
+	default m if !MEDIA_SUBDRV_AUTOSELECT
+	help
+	  MaxLinear MxL301RF OFDM tuner driver.
 endmenu

drivers/media/tuners/Makefile

···
 obj-$(CONFIG_MEDIA_TUNER_FC0013) += fc0013.o
 obj-$(CONFIG_MEDIA_TUNER_IT913X) += it913x.o
 obj-$(CONFIG_MEDIA_TUNER_R820T) += r820t.o
+obj-$(CONFIG_MEDIA_TUNER_MXL301RF) += mxl301rf.o
 
 ccflags-y += -I$(srctree)/drivers/media/dvb-core
 ccflags-y += -I$(srctree)/drivers/media/dvb-frontends

drivers/media/tuners/mxl301rf.c

···
+/*
+ * MaxLinear MxL301RF OFDM tuner driver
+ *
+ * Copyright (C) 2014 Akihiro Tsukada <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * NOTICE:
+ * This driver is incomplete and lacks init/config of the chips,
+ * as the necessary info is not disclosed.
+ * Other features like get_if_frequency() are missing as well.
+ * It assumes that users of this driver (such as a PCI bridge of
+ * DTV receiver cards) properly init and configure the chip
+ * via I2C *before* calling this driver's init() function.
+ *
+ * Currently, PT3 driver is the only one that uses this driver,
+ * and contains init/config code in its firmware.
+ * Thus some part of the code might be dependent on PT3 specific config.
+ */
+
+#include <linux/kernel.h>
+#include "mxl301rf.h"
+
+struct mxl301rf_state {
+	struct mxl301rf_config cfg;
+	struct i2c_client *i2c;
+};
+
+static struct mxl301rf_state *cfg_to_state(struct mxl301rf_config *c)
+{
+	return container_of(c, struct mxl301rf_state, cfg);
+}
+
+static int raw_write(struct mxl301rf_state *state, const u8 *buf, int len)
+{
+	int ret;
+
+	ret = i2c_master_send(state->i2c, buf, len);
+	if (ret >= 0 && ret < len)
+		ret = -EIO;
+	return (ret == len) ? 0 : ret;
+}
+
+static int reg_write(struct mxl301rf_state *state, u8 reg, u8 val)
+{
+	u8 buf[2] = { reg, val };
+
+	return raw_write(state, buf, 2);
+}
+
+static int reg_read(struct mxl301rf_state *state, u8 reg, u8 *val)
+{
+	u8 wbuf[2] = { 0xfb, reg };
+	int ret;
+
+	ret = raw_write(state, wbuf, sizeof(wbuf));
+	if (ret == 0)
+		ret = i2c_master_recv(state->i2c, val, 1);
+	if (ret >= 0 && ret < 1)
+		ret = -EIO;
+	return (ret == 1) ? 0 : ret;
+}
+
+/* tuner_ops */
+
+/* get RSSI and update propery cache, set to *out in % */
+static int mxl301rf_get_rf_strength(struct dvb_frontend *fe, u16 *out)
+{
+	struct mxl301rf_state *state;
+	int ret;
+	u8  rf_in1, rf_in2, rf_off1, rf_off2;
+	u16 rf_in, rf_off;
+	s64 level;
+	struct dtv_fe_stats *rssi;
+
+	rssi = &fe->dtv_property_cache.strength;
+	rssi->len = 1;
+	rssi->stat[0].scale = FE_SCALE_NOT_AVAILABLE;
+	*out = 0;
+
+	state = fe->tuner_priv;
+	ret = reg_write(state, 0x14, 0x01);
+	if (ret < 0)
+		return ret;
+	usleep_range(1000, 2000);
+
+	ret = reg_read(state, 0x18, &rf_in1);
+	if (ret == 0)
+		ret = reg_read(state, 0x19, &rf_in2);
+	if (ret == 0)
+		ret = reg_read(state, 0xd6, &rf_off1);
+	if (ret == 0)
+		ret = reg_read(state, 0xd7, &rf_off2);
+	if (ret != 0)
+		return ret;
+
+	rf_in = (rf_in2 & 0x07) << 8 | rf_in1;
+	rf_off = (rf_off2 & 0x0f) << 5 | (rf_off1 >> 3);
+	level = rf_in - rf_off - (113 << 3); /* x8 dBm */
+	level = level * 1000 / 8;
+	rssi->stat[0].svalue = level;
+	rssi->stat[0].scale = FE_SCALE_DECIBEL;
+	/* *out = (level - min) * 100 / (max - min) */
+	*out = (rf_in - rf_off + (1 << 9) - 1) * 100 / ((5 << 9) - 2);
+	return 0;
+}
+
+/* spur shift parameters */
+struct shf {
+	u32	freq;		/* Channel center frequency */
+	u32	ofst_th;	/* Offset frequency threshold */
+	u8	shf_val;	/* Spur shift value */
+	u8	shf_dir;	/* Spur shift direction */
+};
+
+static const struct shf shf_tab[] = {
+	{  64500, 500, 0x92, 0x07 },
+	{ 191500, 300, 0xe2, 0x07 },
+	{ 205500, 500, 0x2c, 0x04 },
+	{ 212500, 500, 0x1e, 0x04 },
+	{ 226500, 500, 0xd4, 0x07 },
+	{  99143, 500, 0x9c, 0x07 },
+	{ 173143, 500, 0xd4, 0x07 },
+	{ 191143, 300, 0xd4, 0x07 },
+	{ 207143, 500, 0xce, 0x07 },
+	{ 225143, 500, 0xce, 0x07 },
+	{ 243143, 500, 0xd4, 0x07 },
+	{ 261143, 500, 0xd4, 0x07 },
+	{ 291143, 500, 0xd4, 0x07 },
+	{ 339143, 500, 0x2c, 0x04 },
+	{ 117143, 500, 0x7a, 0x07 },
+	{ 135143, 300, 0x7a, 0x07 },
+	{ 153143, 500, 0x01, 0x07 }
+};
+
+struct reg_val {
+	u8 reg;
+	u8 val;
+} __attribute__ ((__packed__));
+
+static const struct reg_val set_idac[] = {
+	{ 0x0d, 0x00 },
+	{ 0x0c, 0x67 },
+	{ 0x6f, 0x89 },
+	{ 0x70, 0x0c },
+	{ 0x6f, 0x8a },
+	{ 0x70, 0x0e },
+	{ 0x6f, 0x8b },
+	{ 0x70, 0x1c },
+};
+
+static int mxl301rf_set_params(struct dvb_frontend *fe)
+{
+	struct reg_val tune0[] = {
+		{ 0x13, 0x00 },		/* abort tuning */
+		{ 0x3b, 0xc0 },
+		{ 0x3b, 0x80 },
+		{ 0x10, 0x95 },		/* BW */
+		{ 0x1a, 0x05 },
+		{ 0x61, 0x00 },		/* spur shift value (placeholder) */
+		{ 0x62, 0xa0 }		/* spur shift direction (placeholder) */
+	};
+
+	struct reg_val tune1[] = {
+		{ 0x11, 0x40 },		/* RF frequency L (placeholder) */
+		{ 0x12, 0x0e },		/* RF frequency H (placeholder) */
+		{ 0x13, 0x01 }		/* start tune */
+	};
+
+	struct mxl301rf_state *state;
+	u32 freq;
+	u16 f;
+	u32 tmp, div;
+	int i, ret;
+
+	state = fe->tuner_priv;
+	freq = fe->dtv_property_cache.frequency;
+
+	/* spur shift function (for analog) */
+	for (i = 0; i < ARRAY_SIZE(shf_tab); i++) {
+		if (freq >= (shf_tab[i].freq - shf_tab[i].ofst_th) * 1000 &&
+		    freq <= (shf_tab[i].freq + shf_tab[i].ofst_th) * 1000) {
+			tune0[5].val = shf_tab[i].shf_val;
+			tune0[6].val = 0xa0 | shf_tab[i].shf_dir;
+			break;
+		}
+	}
+	ret = raw_write(state, (u8 *) tune0, sizeof(tune0));
+	if (ret < 0)
+		goto failed;
+	usleep_range(3000, 4000);
+
+	/* convert freq to 10.6 fixed point float [MHz] */
+	f = freq / 1000000;
+	tmp = freq % 1000000;
+	div = 1000000;
+	for (i = 0; i < 6; i++) {
+		f <<= 1;
+		div >>= 1;
+		if (tmp > div) {
+			tmp -= div;
+			f |= 1;
+		}
+	}
+	if (tmp > 7812)
+		f++;
+	tune1[0].val = f & 0xff;
+	tune1[1].val = f >> 8;
+	ret = raw_write(state, (u8 *) tune1, sizeof(tune1));
+	if (ret < 0)
+		goto failed;
+	msleep(31);
+
+	ret = reg_write(state, 0x1a, 0x0d);
+	if (ret < 0)
+		goto failed;
+	ret = raw_write(state, (u8 *) set_idac, sizeof(set_idac));
+	if (ret < 0)
+		goto failed;
+	return 0;
+
+failed:
+	dev_warn(&state->i2c->dev, "(%s) failed. [adap%d-fe%d]\n",
+		__func__, fe->dvb->num, fe->id);
+	return ret;
+}
+
+static const struct reg_val standby_data[] = {
+	{ 0x01, 0x00 },
+	{ 0x13, 0x00 }
+};
+
+static int mxl301rf_sleep(struct dvb_frontend *fe)
+{
+	struct mxl301rf_state *state;
+	int ret;
+
+	state = fe->tuner_priv;
+	ret = raw_write(state, (u8 *)standby_data, sizeof(standby_data));
+	if (ret < 0)
+		dev_warn(&state->i2c->dev, "(%s) failed. [adap%d-fe%d]\n",
+			__func__, fe->dvb->num, fe->id);
+	return ret;
+}
+
+
+/* init sequence is not public.
+ * the parent must have init'ed the device.
+ * just wake up here.
+ */
+static int mxl301rf_init(struct dvb_frontend *fe)
+{
+	struct mxl301rf_state *state;
+	int ret;
+
+	state = fe->tuner_priv;
+
+	ret = reg_write(state, 0x01, 0x01);
+	if (ret < 0) {
+		dev_warn(&state->i2c->dev, "(%s) failed. [adap%d-fe%d]\n",
+			 __func__, fe->dvb->num, fe->id);
+		return ret;
+	}
+	return 0;
+}
+
+/* I2C driver functions */
+
+static const struct dvb_tuner_ops mxl301rf_ops = {
+	.info = {
+		.name = "MaxLinear MxL301RF",
+
+		.frequency_min =  93000000,
+		.frequency_max = 803142857,
+	},
+
+	.init = mxl301rf_init,
+	.sleep = mxl301rf_sleep,
+
+	.set_params = mxl301rf_set_params,
+	.get_rf_strength = mxl301rf_get_rf_strength,
+};
+
+
+static int mxl301rf_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
+{
+	struct mxl301rf_state *state;
+	struct mxl301rf_config *cfg;
+	struct dvb_frontend *fe;
+
+	state = kzalloc(sizeof(*state), GFP_KERNEL);
+	if (!state)
+		return -ENOMEM;
+
+	state->i2c = client;
+	cfg = client->dev.platform_data;
+
+	memcpy(&state->cfg, cfg, sizeof(state->cfg));
+	fe = cfg->fe;
+	fe->tuner_priv = state;
+	memcpy(&fe->ops.tuner_ops, &mxl301rf_ops, sizeof(mxl301rf_ops));
+
+	i2c_set_clientdata(client, &state->cfg);
+	dev_info(&client->dev, "MaxLinear MxL301RF attached.\n");
+	return 0;
+}
+
+static int mxl301rf_remove(struct i2c_client *client)
+{
+	struct mxl301rf_state *state;
+
+	state = cfg_to_state(i2c_get_clientdata(client));
+	state->cfg.fe->tuner_priv = NULL;
+	kfree(state);
+	return 0;
+}
+
+
+static const struct i2c_device_id mxl301rf_id[] = {
+	{"mxl301rf", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, mxl301rf_id);
+
+static struct i2c_driver mxl301rf_driver = {
+	.driver = {
+		.name	= "mxl301rf",
+	},
+	.probe		= mxl301rf_probe,
+	.remove		= mxl301rf_remove,
+	.id_table	= mxl301rf_id,
+};
+
+module_i2c_driver(mxl301rf_driver);
+
+MODULE_DESCRIPTION("MaxLinear MXL301RF tuner");
+MODULE_AUTHOR("Akihiro TSUKADA");
+MODULE_LICENSE("GPL");

drivers/media/tuners/mxl301rf.h

···
+/*
+ * MaxLinear MxL301RF OFDM tuner driver
+ *
+ * Copyright (C) 2014 Akihiro Tsukada <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef MXL301RF_H
+#define MXL301RF_H
+
+#include "dvb_frontend.h"
+
+struct mxl301rf_config {
+	struct dvb_frontend *fe;
+};
+
+#endif /* MXL301RF_H */