/*
 *    Support for OR51132 (pcHDTV HD-3000) - VSB/QAM
 *
 *
 *    Copyright (C) 2007 Trent Piepho <xyzzy@speakeasy.org>
 *
 *    Copyright (C) 2005 Kirk Lapray <kirk_lapray@bigfoot.com>
 *
 *    Based on code from Jack Kelliher (kelliher@xmission.com)
 *                           Copyright (C) 2002 & pcHDTV, inc.
 *
 *    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.
 *
*/

/*
 * This driver needs two external firmware files. Please copy
 * "dvb-fe-or51132-vsb.fw" and "dvb-fe-or51132-qam.fw" to
 * /usr/lib/hotplug/firmware/ or /lib/firmware/
 * (depending on configuration of firmware hotplug).
 */
#define OR51132_VSB_FIRMWARE "dvb-fe-or51132-vsb.fw"
#define OR51132_QAM_FIRMWARE "dvb-fe-or51132-qam.fw"

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <asm/byteorder.h>

#include "dvb_math.h"
#include "dvb_frontend.h"
#include "or51132.h"

static int debug;
#define dprintk(args...) \
        do { \
                if (debug) printk(KERN_DEBUG "or51132: " args); \
        } while (0)


struct or51132_state
{
        struct i2c_adapter* i2c;

        /* Configuration settings */
        const struct or51132_config* config;

        struct dvb_frontend frontend;

        /* Demodulator private data */
        enum fe_modulation current_modulation;
        u32 snr; /* Result of last SNR calculation */

        /* Tuner private data */
        u32 current_frequency;
};


/* Write buffer to demod */
static int or51132_writebuf(struct or51132_state *state, const u8 *buf, int len)
{
        int err;
        struct i2c_msg msg = { .addr = state->config->demod_address,
                               .flags = 0, .buf = (u8*)buf, .len = len };

        /* msleep(20); */ /* doesn't appear to be necessary */
        if ((err = i2c_transfer(state->i2c, &msg, 1)) != 1) {
                printk(KERN_WARNING "or51132: I2C write (addr 0x%02x len %d) error: %d\n",
                       msg.addr, msg.len, err);
                return -EREMOTEIO;
        }
        return 0;
}

/* Write constant bytes, e.g. or51132_writebytes(state, 0x04, 0x42, 0x00);
   Less code and more efficient that loading a buffer on the stack with
   the bytes to send and then calling or51132_writebuf() on that. */
#define or51132_writebytes(state, data...)  \
        ({ static const u8 _data[] = {data}; \
        or51132_writebuf(state, _data, sizeof(_data)); })

/* Read data from demod into buffer.  Returns 0 on success. */
static int or51132_readbuf(struct or51132_state *state, u8 *buf, int len)
{
        int err;
        struct i2c_msg msg = { .addr = state->config->demod_address,
                               .flags = I2C_M_RD, .buf = buf, .len = len };

        /* msleep(20); */ /* doesn't appear to be necessary */
        if ((err = i2c_transfer(state->i2c, &msg, 1)) != 1) {
                printk(KERN_WARNING "or51132: I2C read (addr 0x%02x len %d) error: %d\n",
                       msg.addr, msg.len, err);
                return -EREMOTEIO;
        }
        return 0;
}

/* Reads a 16-bit demod register.  Returns <0 on error. */
static int or51132_readreg(struct or51132_state *state, u8 reg)
{
        u8 buf[2] = { 0x04, reg };
        struct i2c_msg msg[2] = {
                {.addr = state->config->demod_address, .flags = 0,
                 .buf = buf, .len = 2 },
                {.addr = state->config->demod_address, .flags = I2C_M_RD,
                 .buf = buf, .len = 2 }};
        int err;

        if ((err = i2c_transfer(state->i2c, msg, 2)) != 2) {
                printk(KERN_WARNING "or51132: I2C error reading register %d: %d\n",
                       reg, err);
                return -EREMOTEIO;
        }
        return buf[0] | (buf[1] << 8);
}

static int or51132_load_firmware (struct dvb_frontend* fe, const struct firmware *fw)
{
        struct or51132_state* state = fe->demodulator_priv;
        static const u8 run_buf[] = {0x7F,0x01};
        u8 rec_buf[8];
        u32 firmwareAsize, firmwareBsize;
        int i,ret;

        dprintk("Firmware is %Zd bytes\n",fw->size);

        /* Get size of firmware A and B */
        firmwareAsize = le32_to_cpu(*((__le32*)fw->data));
        dprintk("FirmwareA is %i bytes\n",firmwareAsize);
        firmwareBsize = le32_to_cpu(*((__le32*)(fw->data+4)));
        dprintk("FirmwareB is %i bytes\n",firmwareBsize);

        /* Upload firmware */
        if ((ret = or51132_writebuf(state, &fw->data[8], firmwareAsize))) {
                printk(KERN_WARNING "or51132: load_firmware error 1\n");
                return ret;
        }
        if ((ret = or51132_writebuf(state, &fw->data[8+firmwareAsize],
                                    firmwareBsize))) {
                printk(KERN_WARNING "or51132: load_firmware error 2\n");
                return ret;
        }

        if ((ret = or51132_writebuf(state, run_buf, 2))) {
                printk(KERN_WARNING "or51132: load_firmware error 3\n");
                return ret;
        }
        if ((ret = or51132_writebuf(state, run_buf, 2))) {
                printk(KERN_WARNING "or51132: load_firmware error 4\n");
                return ret;
        }

        /* 50ms for operation to begin */
        msleep(50);

        /* Read back ucode version to besure we loaded correctly and are really up and running */
        /* Get uCode version */
        if ((ret = or51132_writebytes(state, 0x10, 0x10, 0x00))) {
                printk(KERN_WARNING "or51132: load_firmware error a\n");
                return ret;
        }
        if ((ret = or51132_writebytes(state, 0x04, 0x17))) {
                printk(KERN_WARNING "or51132: load_firmware error b\n");
                return ret;
        }
        if ((ret = or51132_writebytes(state, 0x00, 0x00))) {
                printk(KERN_WARNING "or51132: load_firmware error c\n");
                return ret;
        }
        for (i=0;i<4;i++) {
                /* Once upon a time, this command might have had something
                   to do with getting the firmware version, but it's
                   not used anymore:
                   {0x04,0x00,0x30,0x00,i+1} */
                /* Read 8 bytes, two bytes at a time */
                if ((ret = or51132_readbuf(state, &rec_buf[i*2], 2))) {
                        printk(KERN_WARNING
                               "or51132: load_firmware error d - %d\n",i);
                        return ret;
                }
        }

        printk(KERN_WARNING
               "or51132: Version: %02X%02X%02X%02X-%02X%02X%02X%02X (%02X%01X-%01X-%02X%01X-%01X)\n",
               rec_buf[1],rec_buf[0],rec_buf[3],rec_buf[2],
               rec_buf[5],rec_buf[4],rec_buf[7],rec_buf[6],
               rec_buf[3],rec_buf[2]>>4,rec_buf[2]&0x0f,
               rec_buf[5],rec_buf[4]>>4,rec_buf[4]&0x0f);

        if ((ret = or51132_writebytes(state, 0x10, 0x00, 0x00))) {
                printk(KERN_WARNING "or51132: load_firmware error e\n");
                return ret;
        }
        return 0;
};

static int or51132_init(struct dvb_frontend* fe)
{
        return 0;
}

static int or51132_read_ber(struct dvb_frontend* fe, u32* ber)
{
        *ber = 0;
        return 0;
}

static int or51132_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
{
        *ucblocks = 0;
        return 0;
}

static int or51132_sleep(struct dvb_frontend* fe)
{
        return 0;
}

static int or51132_setmode(struct dvb_frontend* fe)
{
        struct or51132_state* state = fe->demodulator_priv;
        u8 cmd_buf1[3] = {0x04, 0x01, 0x5f};
        u8 cmd_buf2[3] = {0x1c, 0x00, 0 };

        dprintk("setmode %d\n",(int)state->current_modulation);

        switch (state->current_modulation) {
        case VSB_8:
                /* Auto CH, Auto NTSC rej, MPEGser, MPEG2tr, phase noise-high */
                cmd_buf1[2] = 0x50;
                /* REC MODE inv IF spectrum, Normal */
                cmd_buf2[1] = 0x03;
                /* Channel MODE ATSC/VSB8 */
                cmd_buf2[2] = 0x06;
                break;
        /* All QAM modes are:
           Auto-deinterleave; MPEGser, MPEG2tr, phase noise-high
           REC MODE Normal Carrier Lock */
        case QAM_AUTO:
                /* Channel MODE Auto QAM64/256 */
                cmd_buf2[2] = 0x4f;
                break;
        case QAM_256:
                /* Channel MODE QAM256 */
                cmd_buf2[2] = 0x45;
                break;
        case QAM_64:
                /* Channel MODE QAM64 */
                cmd_buf2[2] = 0x43;
                break;
        default:
                printk(KERN_WARNING
                       "or51132: setmode: Modulation set to unsupported value (%d)\n",
                       state->current_modulation);
                return -EINVAL;
        }

        /* Set Receiver 1 register */
        if (or51132_writebuf(state, cmd_buf1, 3)) {
                printk(KERN_WARNING "or51132: set_mode error 1\n");
                return -EREMOTEIO;
        }
        dprintk("set #1 to %02x\n", cmd_buf1[2]);

        /* Set operation mode in Receiver 6 register */
        if (or51132_writebuf(state, cmd_buf2, 3)) {
                printk(KERN_WARNING "or51132: set_mode error 2\n");
                return -EREMOTEIO;
        }
        dprintk("set #6 to 0x%02x%02x\n", cmd_buf2[1], cmd_buf2[2]);

        return 0;
}

/* Some modulations use the same firmware.  This classifies modulations
   by the firmware they use. */
#define MOD_FWCLASS_UNKNOWN     0
#define MOD_FWCLASS_VSB         1
#define MOD_FWCLASS_QAM         2
static int modulation_fw_class(enum fe_modulation modulation)
{
        switch(modulation) {
        case VSB_8:
                return MOD_FWCLASS_VSB;
        case QAM_AUTO:
        case QAM_64:
        case QAM_256:
                return MOD_FWCLASS_QAM;
        default:
                return MOD_FWCLASS_UNKNOWN;
        }
}

static int or51132_set_parameters(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *p = &fe->dtv_property_cache;
        int ret;
        struct or51132_state* state = fe->demodulator_priv;
        const struct firmware *fw;
        const char *fwname;
        int clock_mode;

        /* Upload new firmware only if we need a different one */
        if (modulation_fw_class(state->current_modulation) !=
            modulation_fw_class(p->modulation)) {
                switch (modulation_fw_class(p->modulation)) {
                case MOD_FWCLASS_VSB:
                        dprintk("set_parameters VSB MODE\n");
                        fwname = OR51132_VSB_FIRMWARE;

                        /* Set non-punctured clock for VSB */
                        clock_mode = 0;
                        break;
                case MOD_FWCLASS_QAM:
                        dprintk("set_parameters QAM MODE\n");
                        fwname = OR51132_QAM_FIRMWARE;

                        /* Set punctured clock for QAM */
                        clock_mode = 1;
                        break;
                default:
                        printk("or51132: Modulation type(%d) UNSUPPORTED\n",
                               p->modulation);
                        return -1;
                }
                printk("or51132: Waiting for firmware upload(%s)...\n",
                       fwname);
                ret = request_firmware(&fw, fwname, state->i2c->dev.parent);
                if (ret) {
                        printk(KERN_WARNING "or51132: No firmware up"
                               "loaded(timeout or file not found?)\n");
                        return ret;
                }
                ret = or51132_load_firmware(fe, fw);
                release_firmware(fw);
                if (ret) {
                        printk(KERN_WARNING "or51132: Writing firmware to "
                               "device failed!\n");
                        return ret;
                }
                printk("or51132: Firmware upload complete.\n");
                state->config->set_ts_params(fe, clock_mode);
        }
        /* Change only if we are actually changing the modulation */
        if (state->current_modulation != p->modulation) {
                state->current_modulation = p->modulation;
                or51132_setmode(fe);
        }

        if (fe->ops.tuner_ops.set_params) {
                fe->ops.tuner_ops.set_params(fe);
                if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
        }

        /* Set to current mode */
        or51132_setmode(fe);

        /* Update current frequency */
        state->current_frequency = p->frequency;
        return 0;
}

static int or51132_get_parameters(struct dvb_frontend* fe)
{
        struct dtv_frontend_properties *p = &fe->dtv_property_cache;
        struct or51132_state* state = fe->demodulator_priv;
        int status;
        int retry = 1;

start:
        /* Receiver Status */
        if ((status = or51132_readreg(state, 0x00)) < 0) {
                printk(KERN_WARNING "or51132: get_parameters: error reading receiver status\n");
                return -EREMOTEIO;
        }
        switch(status&0xff) {
        case 0x06:
                p->modulation = VSB_8;
                break;
        case 0x43:
                p->modulation = QAM_64;
                break;
        case 0x45:
                p->modulation = QAM_256;
                break;
        default:
                if (retry--)
                        goto start;
                printk(KERN_WARNING "or51132: unknown status 0x%02x\n",
                       status&0xff);
                return -EREMOTEIO;
        }

        /* FIXME: Read frequency from frontend, take AFC into account */
        p->frequency = state->current_frequency;

        /* FIXME: How to read inversion setting? Receiver 6 register? */
        p->inversion = INVERSION_AUTO;

        return 0;
}

static int or51132_read_status(struct dvb_frontend *fe, enum fe_status *status)
{
        struct or51132_state* state = fe->demodulator_priv;
        int reg;

        /* Receiver Status */
        if ((reg = or51132_readreg(state, 0x00)) < 0) {
                printk(KERN_WARNING "or51132: read_status: error reading receiver status: %d\n", reg);
                *status = 0;
                return -EREMOTEIO;
        }
        dprintk("%s: read_status %04x\n", __func__, reg);

        if (reg & 0x0100) /* Receiver Lock */
                *status = FE_HAS_SIGNAL|FE_HAS_CARRIER|FE_HAS_VITERBI|
                          FE_HAS_SYNC|FE_HAS_LOCK;
        else
                *status = 0;
        return 0;
}

/* Calculate SNR estimation (scaled by 2^24)

   8-VSB SNR and QAM equations from Oren datasheets

   For 8-VSB:
     SNR[dB] = 10 * log10(897152044.8282 / MSE^2 ) - K

     Where K = 0 if NTSC rejection filter is OFF; and
           K = 3 if NTSC rejection filter is ON

   For QAM64:
     SNR[dB] = 10 * log10(897152044.8282 / MSE^2 )

   For QAM256:
     SNR[dB] = 10 * log10(907832426.314266  / MSE^2 )

   We re-write the snr equation as:
     SNR * 2^24 = 10*(c - 2*intlog10(MSE))
   Where for QAM256, c = log10(907832426.314266) * 2^24
   and for 8-VSB and QAM64, c = log10(897152044.8282) * 2^24 */

static u32 calculate_snr(u32 mse, u32 c)
{
        if (mse == 0) /* No signal */
                return 0;

        mse = 2*intlog10(mse);
        if (mse > c) {
                /* Negative SNR, which is possible, but realisticly the
                demod will lose lock before the signal gets this bad.  The
                API only allows for unsigned values, so just return 0 */
                return 0;
        }
        return 10*(c - mse);
}

static int or51132_read_snr(struct dvb_frontend* fe, u16* snr)
{
        struct or51132_state* state = fe->demodulator_priv;
        int noise, reg;
        u32 c, usK = 0;
        int retry = 1;

start:
        /* SNR after Equalizer */
        noise = or51132_readreg(state, 0x02);
        if (noise < 0) {
                printk(KERN_WARNING "or51132: read_snr: error reading equalizer\n");
                return -EREMOTEIO;
        }
        dprintk("read_snr noise (%d)\n", noise);

        /* Read status, contains modulation type for QAM_AUTO and
           NTSC filter for VSB */
        reg = or51132_readreg(state, 0x00);
        if (reg < 0) {
                printk(KERN_WARNING "or51132: read_snr: error reading receiver status\n");
                return -EREMOTEIO;
        }

        switch (reg&0xff) {
        case 0x06:
                if (reg & 0x1000) usK = 3 << 24;
                /* Fall through to QAM64 case */
        case 0x43:
                c = 150204167;
                break;
        case 0x45:
                c = 150290396;
                break;
        default:
                printk(KERN_WARNING "or51132: unknown status 0x%02x\n", reg&0xff);
                if (retry--) goto start;
                return -EREMOTEIO;
        }
        dprintk("%s: modulation %02x, NTSC rej O%s\n", __func__,
                reg&0xff, reg&0x1000?"n":"ff");

        /* Calculate SNR using noise, c, and NTSC rejection correction */
        state->snr = calculate_snr(noise, c) - usK;
        *snr = (state->snr) >> 16;

        dprintk("%s: noise = 0x%08x, snr = %d.%02d dB\n", __func__, noise,
                state->snr >> 24, (((state->snr>>8) & 0xffff) * 100) >> 16);

        return 0;
}

static int or51132_read_signal_strength(struct dvb_frontend* fe, u16* strength)
{
        /* Calculate Strength from SNR up to 35dB */
        /* Even though the SNR can go higher than 35dB, there is some comfort */
        /* factor in having a range of strong signals that can show at 100%   */
        struct or51132_state* state = (struct or51132_state*) fe->demodulator_priv;
        u16 snr;
        int ret;

        ret = fe->ops.read_snr(fe, &snr);
        if (ret != 0)
                return ret;
        /* Rather than use the 8.8 value snr, use state->snr which is 8.24 */
        /* scale the range 0 - 35*2^24 into 0 - 65535 */
        if (state->snr >= 8960 * 0x10000)
                *strength = 0xffff;
        else
                *strength = state->snr / 8960;

        return 0;
}

static int or51132_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings* fe_tune_settings)
{
        fe_tune_settings->min_delay_ms = 500;
        fe_tune_settings->step_size = 0;
        fe_tune_settings->max_drift = 0;

        return 0;
}

static void or51132_release(struct dvb_frontend* fe)
{
        struct or51132_state* state = fe->demodulator_priv;
        kfree(state);
}

static struct dvb_frontend_ops or51132_ops;

struct dvb_frontend* or51132_attach(const struct or51132_config* config,
                                    struct i2c_adapter* i2c)
{
        struct or51132_state* state = NULL;

        /* Allocate memory for the internal state */
        state = kzalloc(sizeof(struct or51132_state), GFP_KERNEL);
        if (state == NULL)
                return NULL;

        /* Setup the state */
        state->config = config;
        state->i2c = i2c;
        state->current_frequency = -1;
        state->current_modulation = -1;

        /* Create dvb_frontend */
        memcpy(&state->frontend.ops, &or51132_ops, sizeof(struct dvb_frontend_ops));
        state->frontend.demodulator_priv = state;
        return &state->frontend;
}

static struct dvb_frontend_ops or51132_ops = {
        .delsys = { SYS_ATSC, SYS_DVBC_ANNEX_B },
        .info = {
                .name                   = "Oren OR51132 VSB/QAM Frontend",
                .frequency_min          = 44000000,
                .frequency_max          = 958000000,
                .frequency_stepsize     = 166666,
                .caps = FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
                        FE_CAN_FEC_5_6 | FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
                        FE_CAN_QAM_64 | FE_CAN_QAM_256 | FE_CAN_QAM_AUTO |
                        FE_CAN_8VSB
        },

        .release = or51132_release,

        .init = or51132_init,
        .sleep = or51132_sleep,

        .set_frontend = or51132_set_parameters,
        .get_frontend = or51132_get_parameters,
        .get_tune_settings = or51132_get_tune_settings,

        .read_status = or51132_read_status,
        .read_ber = or51132_read_ber,
        .read_signal_strength = or51132_read_signal_strength,
        .read_snr = or51132_read_snr,
        .read_ucblocks = or51132_read_ucblocks,
};

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

MODULE_DESCRIPTION("OR51132 ATSC [pcHDTV HD-3000] (8VSB & ITU J83 AnnexB FEC QAM64/256) Demodulator Driver");
MODULE_AUTHOR("Kirk Lapray");
MODULE_AUTHOR("Trent Piepho");
MODULE_LICENSE("GPL");

EXPORT_SYMBOL(or51132_attach);