// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Driver for Maxim MAX2165 silicon tuner
 *
 *  Copyright (c) 2009 David T. L. Wong <davidtlwong@gmail.com>
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/videodev2.h>
#include <linux/delay.h>
#include <linux/dvb/frontend.h>
#include <linux/i2c.h>
#include <linux/slab.h>

#include <media/dvb_frontend.h>

#include "max2165.h"
#include "max2165_priv.h"
#include "tuner-i2c.h"

#define dprintk(args...) \
	do { \
		if (debug) \
			printk(KERN_DEBUG "max2165: " args); \
	} while (0)

static int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Turn on/off debugging (default:off).");

static int max2165_write_reg(struct max2165_priv *priv, u8 reg, u8 data)
{
	int ret;
	u8 buf[] = { reg, data };
	struct i2c_msg msg = { .flags = 0, .buf = buf, .len = 2 };

	msg.addr = priv->config->i2c_address;

	if (debug >= 2)
		dprintk("%s: reg=0x%02X, data=0x%02X\n", __func__, reg, data);

	ret = i2c_transfer(priv->i2c, &msg, 1);

	if (ret != 1)
		dprintk("%s: error reg=0x%x, data=0x%x, ret=%i\n",
			__func__, reg, data, ret);

	return (ret != 1) ? -EIO : 0;
}

static int max2165_read_reg(struct max2165_priv *priv, u8 reg, u8 *p_data)
{
	int ret;
	u8 dev_addr = priv->config->i2c_address;

	u8 b0[] = { reg };
	u8 b1[] = { 0 };
	struct i2c_msg msg[] = {
		{ .addr = dev_addr, .flags = 0, .buf = b0, .len = 1 },
		{ .addr = dev_addr, .flags = I2C_M_RD, .buf = b1, .len = 1 },
	};

	ret = i2c_transfer(priv->i2c, msg, 2);
	if (ret != 2) {
		dprintk("%s: error reg=0x%x, ret=%i\n", __func__, reg, ret);
		return -EIO;
	}

	*p_data = b1[0];
	if (debug >= 2)
		dprintk("%s: reg=0x%02X, data=0x%02X\n",
			__func__, reg, b1[0]);
	return 0;
}

static int max2165_mask_write_reg(struct max2165_priv *priv, u8 reg,
	u8 mask, u8 data)
{
	int ret;
	u8 v;

	data &= mask;
	ret = max2165_read_reg(priv, reg, &v);
	if (ret != 0)
		return ret;
	v &= ~mask;
	v |= data;
	ret = max2165_write_reg(priv, reg, v);

	return ret;
}

static int max2165_read_rom_table(struct max2165_priv *priv)
{
	u8 dat[3];
	int i;

	for (i = 0; i < 3; i++) {
		max2165_write_reg(priv, REG_ROM_TABLE_ADDR, i + 1);
		max2165_read_reg(priv, REG_ROM_TABLE_DATA, &dat[i]);
	}

	priv->tf_ntch_low_cfg = dat[0] >> 4;
	priv->tf_ntch_hi_cfg = dat[0] & 0x0F;
	priv->tf_balun_low_ref = dat[1] & 0x0F;
	priv->tf_balun_hi_ref = dat[1] >> 4;
	priv->bb_filter_7mhz_cfg = dat[2] & 0x0F;
	priv->bb_filter_8mhz_cfg = dat[2] >> 4;

	dprintk("tf_ntch_low_cfg = 0x%X\n", priv->tf_ntch_low_cfg);
	dprintk("tf_ntch_hi_cfg = 0x%X\n", priv->tf_ntch_hi_cfg);
	dprintk("tf_balun_low_ref = 0x%X\n", priv->tf_balun_low_ref);
	dprintk("tf_balun_hi_ref = 0x%X\n", priv->tf_balun_hi_ref);
	dprintk("bb_filter_7mhz_cfg = 0x%X\n", priv->bb_filter_7mhz_cfg);
	dprintk("bb_filter_8mhz_cfg = 0x%X\n", priv->bb_filter_8mhz_cfg);

	return 0;
}

static int max2165_set_osc(struct max2165_priv *priv, u8 osc /*MHz*/)
{
	u8 v;

	v = (osc / 2);
	if (v == 2)
		v = 0x7;
	else
		v -= 8;

	max2165_mask_write_reg(priv, REG_PLL_CFG, 0x07, v);

	return 0;
}

static int max2165_set_bandwidth(struct max2165_priv *priv, u32 bw)
{
	u8 val;

	if (bw == 8000000)
		val = priv->bb_filter_8mhz_cfg;
	else
		val = priv->bb_filter_7mhz_cfg;

	max2165_mask_write_reg(priv, REG_BASEBAND_CTRL, 0xF0, val << 4);

	return 0;
}

static int fixpt_div32(u32 dividend, u32 divisor, u32 *quotient, u32 *fraction)
{
	u32 remainder;
	u32 q, f = 0;
	int i;

	if (0 == divisor)
		return -EINVAL;

	q = dividend / divisor;
	remainder = dividend - q * divisor;

	for (i = 0; i < 31; i++) {
		remainder <<= 1;
		if (remainder >= divisor) {
			f += 1;
			remainder -= divisor;
		}
		f <<= 1;
	}

	*quotient = q;
	*fraction = f;

	return 0;
}

static int max2165_set_rf(struct max2165_priv *priv, u32 freq)
{
	u8 tf;
	u8 tf_ntch;
	u32 t;
	u32 quotient, fraction;
	int ret;

	/* Set PLL divider according to RF frequency */
	ret = fixpt_div32(freq / 1000, priv->config->osc_clk * 1000,
			 &quotient, &fraction);
	if (ret != 0)
		return ret;

	/* 20-bit fraction */
	fraction >>= 12;

	max2165_write_reg(priv, REG_NDIV_INT, quotient);
	max2165_mask_write_reg(priv, REG_NDIV_FRAC2, 0x0F, fraction >> 16);
	max2165_write_reg(priv, REG_NDIV_FRAC1, fraction >> 8);
	max2165_write_reg(priv, REG_NDIV_FRAC0, fraction);

	/* Norch Filter */
	tf_ntch = (freq < 725000000) ?
		priv->tf_ntch_low_cfg : priv->tf_ntch_hi_cfg;

	/* Tracking filter balun */
	t = priv->tf_balun_low_ref;
	t += (priv->tf_balun_hi_ref - priv->tf_balun_low_ref)
		* (freq / 1000 - 470000) / (780000 - 470000);

	tf = t;
	dprintk("tf = %X\n", tf);
	tf |= tf_ntch << 4;

	max2165_write_reg(priv, REG_TRACK_FILTER, tf);

	return 0;
}

static void max2165_debug_status(struct max2165_priv *priv)
{
	u8 status, autotune;
	u8 auto_vco_success, auto_vco_active;
	u8 pll_locked;
	u8 dc_offset_low, dc_offset_hi;
	u8 signal_lv_over_threshold;
	u8 vco, vco_sub_band, adc;

	max2165_read_reg(priv, REG_STATUS, &status);
	max2165_read_reg(priv, REG_AUTOTUNE, &autotune);

	auto_vco_success = (status >> 6) & 0x01;
	auto_vco_active = (status >> 5) & 0x01;
	pll_locked = (status >> 4) & 0x01;
	dc_offset_low = (status >> 3) & 0x01;
	dc_offset_hi = (status >> 2) & 0x01;
	signal_lv_over_threshold = status & 0x01;

	vco = autotune >> 6;
	vco_sub_band = (autotune >> 3) & 0x7;
	adc = autotune & 0x7;

	dprintk("auto VCO active: %d, auto VCO success: %d\n",
		auto_vco_active, auto_vco_success);
	dprintk("PLL locked: %d\n", pll_locked);
	dprintk("DC offset low: %d, DC offset high: %d\n",
		dc_offset_low, dc_offset_hi);
	dprintk("Signal lvl over threshold: %d\n", signal_lv_over_threshold);
	dprintk("VCO: %d, VCO Sub-band: %d, ADC: %d\n", vco, vco_sub_band, adc);
}

static int max2165_set_params(struct dvb_frontend *fe)
{
	struct max2165_priv *priv = fe->tuner_priv;
	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
	int ret;

	switch (c->bandwidth_hz) {
	case 7000000:
	case 8000000:
		priv->frequency = c->frequency;
		break;
	default:
		printk(KERN_INFO "MAX2165: bandwidth %d Hz not supported.\n",
		       c->bandwidth_hz);
		return -EINVAL;
	}

	dprintk("%s() frequency=%d\n", __func__, c->frequency);

	if (fe->ops.i2c_gate_ctrl)
		fe->ops.i2c_gate_ctrl(fe, 1);
	max2165_set_bandwidth(priv, c->bandwidth_hz);
	ret = max2165_set_rf(priv, priv->frequency);
	mdelay(50);
	max2165_debug_status(priv);
	if (fe->ops.i2c_gate_ctrl)
		fe->ops.i2c_gate_ctrl(fe, 0);

	if (ret != 0)
		return -EREMOTEIO;

	return 0;
}

static int max2165_get_frequency(struct dvb_frontend *fe, u32 *freq)
{
	struct max2165_priv *priv = fe->tuner_priv;
	dprintk("%s()\n", __func__);
	*freq = priv->frequency;
	return 0;
}

static int max2165_get_bandwidth(struct dvb_frontend *fe, u32 *bw)
{
	struct max2165_priv *priv = fe->tuner_priv;
	dprintk("%s()\n", __func__);

	*bw = priv->bandwidth;
	return 0;
}

static int max2165_get_status(struct dvb_frontend *fe, u32 *status)
{
	struct max2165_priv *priv = fe->tuner_priv;
	u16 lock_status = 0;

	dprintk("%s()\n", __func__);

	if (fe->ops.i2c_gate_ctrl)
			fe->ops.i2c_gate_ctrl(fe, 1);

	max2165_debug_status(priv);
	*status = lock_status;

	if (fe->ops.i2c_gate_ctrl)
			fe->ops.i2c_gate_ctrl(fe, 0);

	return 0;
}

static int max2165_sleep(struct dvb_frontend *fe)
{
	dprintk("%s()\n", __func__);
	return 0;
}

static int max2165_init(struct dvb_frontend *fe)
{
	struct max2165_priv *priv = fe->tuner_priv;
	dprintk("%s()\n", __func__);

	if (fe->ops.i2c_gate_ctrl)
		fe->ops.i2c_gate_ctrl(fe, 1);

	/* Setup initial values */
	/* Fractional Mode on */
	max2165_write_reg(priv, REG_NDIV_FRAC2, 0x18);
	/* LNA on */
	max2165_write_reg(priv, REG_LNA, 0x01);
	max2165_write_reg(priv, REG_PLL_CFG, 0x7A);
	max2165_write_reg(priv, REG_TEST, 0x08);
	max2165_write_reg(priv, REG_SHUTDOWN, 0x40);
	max2165_write_reg(priv, REG_VCO_CTRL, 0x84);
	max2165_write_reg(priv, REG_BASEBAND_CTRL, 0xC3);
	max2165_write_reg(priv, REG_DC_OFFSET_CTRL, 0x75);
	max2165_write_reg(priv, REG_DC_OFFSET_DAC, 0x00);
	max2165_write_reg(priv, REG_ROM_TABLE_ADDR, 0x00);

	max2165_set_osc(priv, priv->config->osc_clk);

	max2165_read_rom_table(priv);

	max2165_set_bandwidth(priv, 8000000);

	if (fe->ops.i2c_gate_ctrl)
			fe->ops.i2c_gate_ctrl(fe, 0);

	return 0;
}

static void max2165_release(struct dvb_frontend *fe)
{
	struct max2165_priv *priv = fe->tuner_priv;
	dprintk("%s()\n", __func__);

	kfree(priv);
	fe->tuner_priv = NULL;
}

static const struct dvb_tuner_ops max2165_tuner_ops = {
	.info = {
		.name              = "Maxim MAX2165",
		.frequency_min_hz  = 470 * MHz,
		.frequency_max_hz  = 862 * MHz,
		.frequency_step_hz =  50 * kHz,
	},

	.release	   = max2165_release,
	.init		   = max2165_init,
	.sleep		   = max2165_sleep,

	.set_params	   = max2165_set_params,
	.set_analog_params = NULL,
	.get_frequency	   = max2165_get_frequency,
	.get_bandwidth	   = max2165_get_bandwidth,
	.get_status	   = max2165_get_status
};

struct dvb_frontend *max2165_attach(struct dvb_frontend *fe,
				   struct i2c_adapter *i2c,
				   struct max2165_config *cfg)
{
	struct max2165_priv *priv = NULL;

	dprintk("%s(%d-%04x)\n", __func__,
		i2c ? i2c_adapter_id(i2c) : -1,
		cfg ? cfg->i2c_address : -1);

	priv = kzalloc(sizeof(struct max2165_priv), GFP_KERNEL);
	if (priv == NULL)
		return NULL;

	memcpy(&fe->ops.tuner_ops, &max2165_tuner_ops,
		sizeof(struct dvb_tuner_ops));

	priv->config = cfg;
	priv->i2c = i2c;
	fe->tuner_priv = priv;

	max2165_init(fe);
	max2165_debug_status(priv);

	return fe;
}
EXPORT_SYMBOL(max2165_attach);

MODULE_AUTHOR("David T. L. Wong <davidtlwong@gmail.com>");
MODULE_DESCRIPTION("Maxim MAX2165 silicon tuner driver");
MODULE_LICENSE("GPL");