V4L/DVB (5947): Adding support for the MT2131 tuner.

This adds support for the Microtune MT2131 tuner. 8VSB mode has been 
tested but QAM support will likely require more register work. Hauppauge 
have not announced any QAM devices using the MT2131 so QAM remains 
undone.

For legal reasons, Microtune allowed us to write a GPL driver providing 
we did not document in significant detail any of the registers. This 
explains the lack of comments or defined on register names.

Signed-off-by: Steven Toth <stoth@hauppauge.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/dvb/frontends/mt2131.c b/drivers/media/dvb/frontends/mt2131.c
new file mode 100644
index 0000000..4fe1e62
--- /dev/null
+++ b/drivers/media/dvb/frontends/mt2131.c
@@ -0,0 +1,308 @@
+/*
+ *  Driver for Microtune MT2131 "QAM/8VSB single chip tuner"
+ *
+ *  Copyright (c) 2006 Steven Toth <stoth@hauppauge.com>
+ *
+ *  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; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  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.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/delay.h>
+#include <linux/dvb/frontend.h>
+#include <linux/i2c.h>
+
+#include "dvb_frontend.h"
+
+#include "mt2131.h"
+#include "mt2131_priv.h"
+
+static int debug;
+module_param(debug, int, 0644);
+MODULE_PARM_DESC(debug, "Turn on/off debugging (default:off).");
+
+#define dprintk(level,fmt, arg...) if (debug >= level) \
+	printk(KERN_INFO "%s: " fmt, "mt2131", ## arg)
+
+static u8 mt2131_config1[] = {
+	0x01,
+	0x50, 0x00, 0x50, 0x80, 0x00, 0x49, 0xfa, 0x88,
+	0x08, 0x77, 0x41, 0x04, 0x00, 0x00, 0x00, 0x32,
+	0x7f, 0xda, 0x4c, 0x00, 0x10, 0xaa, 0x78, 0x80,
+	0xff, 0x68, 0xa0, 0xff, 0xdd, 0x00, 0x00
+};
+
+static u8 mt2131_config2[] = {
+	0x10,
+	0x7f, 0xc8, 0x0a, 0x5f, 0x00, 0x04
+};
+
+static int mt2131_readreg(struct mt2131_priv *priv, u8 reg, u8 *val)
+{
+	struct i2c_msg msg[2] = {
+		{ .addr = priv->cfg->i2c_address, .flags = 0,        .buf = &reg, .len = 1 },
+		{ .addr = priv->cfg->i2c_address, .flags = I2C_M_RD, .buf = val,  .len = 1 },
+	};
+
+	if (i2c_transfer(priv->i2c, msg, 2) != 2) {
+		printk(KERN_WARNING "mt2131 I2C read failed\n");
+		return -EREMOTEIO;
+	}
+	return 0;
+}
+
+static int mt2131_writereg(struct mt2131_priv *priv, u8 reg, u8 val)
+{
+	u8 buf[2] = { reg, val };
+	struct i2c_msg msg = { .addr = priv->cfg->i2c_address, .flags = 0, .buf = buf, .len = 2 };
+
+	if (i2c_transfer(priv->i2c, &msg, 1) != 1) {
+		printk(KERN_WARNING "mt2131 I2C write failed\n");
+		return -EREMOTEIO;
+	}
+	return 0;
+}
+
+static int mt2131_writeregs(struct mt2131_priv *priv,u8 *buf, u8 len)
+{
+	struct i2c_msg msg = { .addr = priv->cfg->i2c_address, .flags = 0, .buf = buf, .len = len };
+
+	if (i2c_transfer(priv->i2c, &msg, 1) != 1) {
+		printk(KERN_WARNING "mt2131 I2C write failed (len=%i)\n",(int)len);
+		return -EREMOTEIO;
+	}
+	return 0;
+}
+
+static int mt2131_set_gpo(struct dvb_frontend *fe, u8 val)
+{
+	struct mt2131_priv *priv = fe->tuner_priv;
+	u8 v;
+
+	mt2131_readreg(priv, 0x07, &v);
+	mt2131_writereg(priv, 0x07, (v & 0xfe) | (val & 0x01));
+
+	return 0;
+}
+
+static int mt2131_set_params(struct dvb_frontend *fe, struct dvb_frontend_parameters *params)
+{
+	struct mt2131_priv *priv;
+	int ret=0, i;
+	u32 freq;
+	u8  if_band_center;
+	u32 f_lo1,f_lo2;
+	u32 div1,num1,div2,num2;
+	u8  b[8];
+	u8 lockval = 0;
+
+	priv = fe->tuner_priv;
+	if (fe->ops.info.type == FE_OFDM)
+		priv->bandwidth = params->u.ofdm.bandwidth;
+	else
+		priv->bandwidth = 0;
+
+	freq = params->frequency / 1000;  // Hz -> kHz
+	dprintk(1, "%s() freq=%d\n", __FUNCTION__, freq);
+
+	f_lo1 = freq + MT2131_IF1 * 1000;
+	f_lo1 = (f_lo1 / 250) * 250;
+	f_lo2 = f_lo1 - freq - MT2131_IF2;
+
+	priv->frequency =  (f_lo1 - f_lo2 - MT2131_IF2) * 1000,
+
+	/* Frequency LO1 = 16MHz * (DIV1 + NUM1/8192 ) */
+	num1 = f_lo1 * 64 / (MT2131_FREF / 128);
+	div1 = num1 / 8192;
+	num1 &= 0x1fff;
+
+	/* Frequency LO2 = 16MHz * (DIV2 + NUM2/8192 ) */
+	num2 = f_lo2 * 64 / (MT2131_FREF / 128);
+	div2 = num2 / 8192;
+	num2 &= 0x1fff;
+
+	if (freq <=   82500) if_band_center = 0x00; else
+	if (freq <=  137500) if_band_center = 0x01; else
+	if (freq <=  192500) if_band_center = 0x02; else
+	if (freq <=  247500) if_band_center = 0x03; else
+	if (freq <=  302500) if_band_center = 0x04; else
+	if (freq <=  357500) if_band_center = 0x05; else
+	if (freq <=  412500) if_band_center = 0x06; else
+	if (freq <=  467500) if_band_center = 0x07; else
+	if (freq <=  522500) if_band_center = 0x08; else
+	if (freq <=  577500) if_band_center = 0x09; else
+	if (freq <=  632500) if_band_center = 0x0A; else
+	if (freq <=  687500) if_band_center = 0x0B; else
+	if (freq <=  742500) if_band_center = 0x0C; else
+	if (freq <=  797500) if_band_center = 0x0D; else
+	if (freq <=  852500) if_band_center = 0x0E; else
+	if (freq <=  907500) if_band_center = 0x0F; else
+	if (freq <=  962500) if_band_center = 0x10; else
+	if (freq <= 1017500) if_band_center = 0x11; else
+	if (freq <= 1072500) if_band_center = 0x12; else if_band_center = 0x13;
+
+	b[0] = 1;
+	b[1] = (num1 >> 5) & 0xFF;
+	b[2] = (num1 & 0x1F);
+	b[3] = div1;
+	b[4] = (num2 >> 5) & 0xFF;
+	b[5] = num2 & 0x1F;
+	b[6] = div2;
+
+	dprintk(1, "IF1: %dMHz IF2: %dMHz\n", MT2131_IF1, MT2131_IF2);
+	dprintk(1, "PLL freq=%dkHz  band=%d\n", (int)freq, (int)if_band_center);
+	dprintk(1, "PLL f_lo1=%dkHz  f_lo2=%dkHz\n", (int)f_lo1, (int)f_lo2);
+	dprintk(1, "PLL div1=%d  num1=%d  div2=%d  num2=%d\n",
+		(int)div1, (int)num1, (int)div2, (int)num2);
+	dprintk(1, "PLL [1..6]: %2x %2x %2x %2x %2x %2x\n",
+		(int)b[1], (int)b[2], (int)b[3], (int)b[4], (int)b[5],
+		(int)b[6]);
+
+	ret = mt2131_writeregs(priv,b,7);
+	if (ret < 0)
+		return ret;
+
+	mt2131_writereg(priv, 0x0b, if_band_center);
+
+	/* Wait for lock */
+	i = 0;
+	do {
+		mt2131_readreg(priv, 0x08, &lockval);
+		if ((lockval & 0x88) == 0x88)
+			break;
+		msleep(4);
+		i++;
+	} while (i < 10);
+
+	return ret;
+}
+
+static int mt2131_get_frequency(struct dvb_frontend *fe, u32 *frequency)
+{
+	struct mt2131_priv *priv = fe->tuner_priv;
+	dprintk(1, "%s()\n", __FUNCTION__);
+	*frequency = priv->frequency;
+	return 0;
+}
+
+static int mt2131_get_bandwidth(struct dvb_frontend *fe, u32 *bandwidth)
+{
+	struct mt2131_priv *priv = fe->tuner_priv;
+	dprintk(1, "%s()\n", __FUNCTION__);
+	*bandwidth = priv->bandwidth;
+	return 0;
+}
+
+static int mt2131_get_status(struct dvb_frontend *fe, u32 *status)
+{
+	struct mt2131_priv *priv = fe->tuner_priv;
+	u8 lock_status = 0;
+	u8 afc_status = 0;
+
+	*status = 0;
+
+	mt2131_readreg(priv, 0x08, &lock_status);
+	if ((lock_status & 0x88) == 0x88)
+		*status = TUNER_STATUS_LOCKED;
+
+	mt2131_readreg(priv, 0x09, &afc_status);
+	dprintk(1, "%s() - LO Status = 0x%x, AFC Status = 0x%x\n",
+		__FUNCTION__, lock_status, afc_status);
+
+	return 0;
+}
+
+static int mt2131_init(struct dvb_frontend *fe)
+{
+	struct mt2131_priv *priv = fe->tuner_priv;
+	int ret;
+	dprintk(1, "%s()\n", __FUNCTION__);
+
+	if ((ret = mt2131_writeregs(priv, mt2131_config1, sizeof(mt2131_config1))) < 0)
+		return ret;
+
+	mt2131_writereg(priv, 0x0b, 0x09);
+	mt2131_writereg(priv, 0x15, 0x47);
+	mt2131_writereg(priv, 0x07, 0xf2);
+	mt2131_writereg(priv, 0x0b, 0x01);
+
+	if ((ret = mt2131_writeregs(priv, mt2131_config2, sizeof(mt2131_config2))) < 0)
+		return ret;
+
+	return ret;
+}
+
+static int mt2131_release(struct dvb_frontend *fe)
+{
+	dprintk(1, "%s()\n", __FUNCTION__);
+	kfree(fe->tuner_priv);
+	fe->tuner_priv = NULL;
+	return 0;
+}
+
+static const struct dvb_tuner_ops mt2131_tuner_ops = {
+	.info = {
+		.name           = "Microtune MT2131",
+		.frequency_min  =  48000000,
+		.frequency_max  = 860000000,
+		.frequency_step =     50000,
+	},
+
+	.release       = mt2131_release,
+	.init          = mt2131_init,
+
+	.set_params    = mt2131_set_params,
+	.get_frequency = mt2131_get_frequency,
+	.get_bandwidth = mt2131_get_bandwidth,
+	.get_status    = mt2131_get_status
+};
+
+struct dvb_frontend * mt2131_attach(struct dvb_frontend *fe, struct i2c_adapter *i2c, struct mt2131_config *cfg, u16 if1)
+{
+	struct mt2131_priv *priv = NULL;
+	u8 id = 0;
+
+	dprintk(1, "%s()\n", __FUNCTION__);
+
+	priv = kzalloc(sizeof(struct mt2131_priv), GFP_KERNEL);
+	if (priv == NULL)
+		return NULL;
+
+	priv->cfg = cfg;
+	priv->bandwidth = 6000000; /* 6MHz */
+	priv->i2c = i2c;
+
+	if (mt2131_readreg(priv, 0, &id) != 0) {
+		kfree(priv);
+		return NULL;
+	}
+	if ( (id != 0x3E) && (id != 0x3F) ) {
+		printk(KERN_ERR "MT2131: Device not found at addr 0x%02x\n", cfg->i2c_address);
+		kfree(priv);
+		return NULL;
+	}
+
+	printk(KERN_INFO "MT2131: successfully identified at address 0x%02x\n", cfg->i2c_address);
+	memcpy(&fe->ops.tuner_ops, &mt2131_tuner_ops, sizeof(struct dvb_tuner_ops));
+
+	fe->tuner_priv = priv;
+	return fe;
+}
+EXPORT_SYMBOL(mt2131_attach);
+
+MODULE_AUTHOR("Steven Toth");
+MODULE_DESCRIPTION("Microtune MT2131 silicon tuner driver");
+MODULE_LICENSE("GPL");