/*
 *  cx18 gpio functions
 *
 *  Derived from ivtv-gpio.c
 *
 *  Copyright (C) 2007  Hans Verkuil <hverkuil@xs4all.nl>
 *  Copyright (C) 2008  Andy Walls <awalls@md.metrocast.net>
 *
 *  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.
 */

#include "cx18-driver.h"
#include "cx18-io.h"
#include "cx18-cards.h"
#include "cx18-gpio.h"
#include "tuner-xc2028.h"

/********************* GPIO stuffs *********************/

/* GPIO registers */
#define CX18_REG_GPIO_IN     0xc72010
#define CX18_REG_GPIO_OUT1   0xc78100
#define CX18_REG_GPIO_DIR1   0xc78108
#define CX18_REG_GPIO_OUT2   0xc78104
#define CX18_REG_GPIO_DIR2   0xc7810c

/*
 * HVR-1600 GPIO pins, courtesy of Hauppauge:
 *
 * gpio0: zilog ir process reset pin
 * gpio1: zilog programming pin (you should never use this)
 * gpio12: cx24227 reset pin
 * gpio13: cs5345 reset pin
*/

/*
 * File scope utility functions
 */
static void gpio_write(struct cx18 *cx)
{
        u32 dir_lo = cx->gpio_dir & 0xffff;
        u32 val_lo = cx->gpio_val & 0xffff;
        u32 dir_hi = cx->gpio_dir >> 16;
        u32 val_hi = cx->gpio_val >> 16;

        cx18_write_reg_expect(cx, dir_lo << 16,
                                        CX18_REG_GPIO_DIR1, ~dir_lo, dir_lo);
        cx18_write_reg_expect(cx, (dir_lo << 16) | val_lo,
                                        CX18_REG_GPIO_OUT1, val_lo, dir_lo);
        cx18_write_reg_expect(cx, dir_hi << 16,
                                        CX18_REG_GPIO_DIR2, ~dir_hi, dir_hi);
        cx18_write_reg_expect(cx, (dir_hi << 16) | val_hi,
                                        CX18_REG_GPIO_OUT2, val_hi, dir_hi);
}

static void gpio_update(struct cx18 *cx, u32 mask, u32 data)
{
        if (mask == 0)
                return;

        mutex_lock(&cx->gpio_lock);
        cx->gpio_val = (cx->gpio_val & ~mask) | (data & mask);
        gpio_write(cx);
        mutex_unlock(&cx->gpio_lock);
}

static void gpio_reset_seq(struct cx18 *cx, u32 active_lo, u32 active_hi,
                           unsigned int assert_msecs,
                           unsigned int recovery_msecs)
{
        u32 mask;

        mask = active_lo | active_hi;
        if (mask == 0)
                return;

        /*
         * Assuming that active_hi and active_lo are a subsets of the bits in
         * gpio_dir.  Also assumes that active_lo and active_hi don't overlap
         * in any bit position
         */

        /* Assert */
        gpio_update(cx, mask, ~active_lo);
        schedule_timeout_uninterruptible(msecs_to_jiffies(assert_msecs));

        /* Deassert */
        gpio_update(cx, mask, ~active_hi);
        schedule_timeout_uninterruptible(msecs_to_jiffies(recovery_msecs));
}

/*
 * GPIO Multiplexer - logical device
 */
static int gpiomux_log_status(struct v4l2_subdev *sd)
{
        struct cx18 *cx = v4l2_get_subdevdata(sd);

        mutex_lock(&cx->gpio_lock);
        CX18_INFO_DEV(sd, "GPIO:  direction 0x%08x, value 0x%08x\n",
                      cx->gpio_dir, cx->gpio_val);
        mutex_unlock(&cx->gpio_lock);
        return 0;
}

static int gpiomux_s_radio(struct v4l2_subdev *sd)
{
        struct cx18 *cx = v4l2_get_subdevdata(sd);

        /*
         * FIXME - work out the cx->active/audio_input mess - this is
         * intended to handle the switch to radio mode and set the
         * audio routing, but we need to update the state in cx
         */
        gpio_update(cx, cx->card->gpio_audio_input.mask,
                        cx->card->gpio_audio_input.radio);
        return 0;
}

static int gpiomux_s_std(struct v4l2_subdev *sd, v4l2_std_id norm)
{
        struct cx18 *cx = v4l2_get_subdevdata(sd);
        u32 data;

        switch (cx->card->audio_inputs[cx->audio_input].muxer_input) {
        case 1:
                data = cx->card->gpio_audio_input.linein;
                break;
        case 0:
                data = cx->card->gpio_audio_input.tuner;
                break;
        default:
                /*
                 * FIXME - work out the cx->active/audio_input mess - this is
                 * intended to handle the switch from radio mode and set the
                 * audio routing, but we need to update the state in cx
                 */
                data = cx->card->gpio_audio_input.tuner;
                break;
        }
        gpio_update(cx, cx->card->gpio_audio_input.mask, data);
        return 0;
}

static int gpiomux_s_audio_routing(struct v4l2_subdev *sd,
                                   u32 input, u32 output, u32 config)
{
        struct cx18 *cx = v4l2_get_subdevdata(sd);
        u32 data;

        switch (input) {
        case 0:
                data = cx->card->gpio_audio_input.tuner;
                break;
        case 1:
                data = cx->card->gpio_audio_input.linein;
                break;
        case 2:
                data = cx->card->gpio_audio_input.radio;
                break;
        default:
                return -EINVAL;
        }
        gpio_update(cx, cx->card->gpio_audio_input.mask, data);
        return 0;
}

static const struct v4l2_subdev_core_ops gpiomux_core_ops = {
        .log_status = gpiomux_log_status,
};

static const struct v4l2_subdev_tuner_ops gpiomux_tuner_ops = {
        .s_radio = gpiomux_s_radio,
};

static const struct v4l2_subdev_audio_ops gpiomux_audio_ops = {
        .s_routing = gpiomux_s_audio_routing,
};

static const struct v4l2_subdev_video_ops gpiomux_video_ops = {
        .s_std = gpiomux_s_std,
};

static const struct v4l2_subdev_ops gpiomux_ops = {
        .core = &gpiomux_core_ops,
        .tuner = &gpiomux_tuner_ops,
        .audio = &gpiomux_audio_ops,
        .video = &gpiomux_video_ops,
};

/*
 * GPIO Reset Controller - logical device
 */
static int resetctrl_log_status(struct v4l2_subdev *sd)
{
        struct cx18 *cx = v4l2_get_subdevdata(sd);

        mutex_lock(&cx->gpio_lock);
        CX18_INFO_DEV(sd, "GPIO:  direction 0x%08x, value 0x%08x\n",
                      cx->gpio_dir, cx->gpio_val);
        mutex_unlock(&cx->gpio_lock);
        return 0;
}

static int resetctrl_reset(struct v4l2_subdev *sd, u32 val)
{
        struct cx18 *cx = v4l2_get_subdevdata(sd);
        const struct cx18_gpio_i2c_slave_reset *p;

        p = &cx->card->gpio_i2c_slave_reset;
        switch (val) {
        case CX18_GPIO_RESET_I2C:
                gpio_reset_seq(cx, p->active_lo_mask, p->active_hi_mask,
                               p->msecs_asserted, p->msecs_recovery);
                break;
        case CX18_GPIO_RESET_Z8F0811:
                /*
                 * Assert timing for the Z8F0811 on HVR-1600 boards:
                 * 1. Assert RESET for min of 4 clock cycles at 18.432 MHz to
                 *    initiate
                 * 2. Reset then takes 66 WDT cycles at 10 kHz + 16 xtal clock
                 *    cycles (6,601,085 nanoseconds ~= 7 milliseconds)
                 * 3. DBG pin must be high before chip exits reset for normal
                 *    operation.  DBG is open drain and hopefully pulled high
                 *    since we don't normally drive it (GPIO 1?) for the
                 *    HVR-1600
                 * 4. Z8F0811 won't exit reset until RESET is deasserted
                 * 5. Zilog comes out of reset, loads reset vector address and
                 *    executes from there. Required recovery delay unknown.
                 */
                gpio_reset_seq(cx, p->ir_reset_mask, 0,
                               p->msecs_asserted, p->msecs_recovery);
                break;
        case CX18_GPIO_RESET_XC2028:
                if (cx->card->tuners[0].tuner == TUNER_XC2028)
                        gpio_reset_seq(cx, (1 << cx->card->xceive_pin), 0,
                                       1, 1);
                break;
        }
        return 0;
}

static const struct v4l2_subdev_core_ops resetctrl_core_ops = {
        .log_status = resetctrl_log_status,
        .reset = resetctrl_reset,
};

static const struct v4l2_subdev_ops resetctrl_ops = {
        .core = &resetctrl_core_ops,
};

/*
 * External entry points
 */
void cx18_gpio_init(struct cx18 *cx)
{
        mutex_lock(&cx->gpio_lock);
        cx->gpio_dir = cx->card->gpio_init.direction;
        cx->gpio_val = cx->card->gpio_init.initial_value;

        if (cx->card->tuners[0].tuner == TUNER_XC2028) {
                cx->gpio_dir |= 1 << cx->card->xceive_pin;
                cx->gpio_val |= 1 << cx->card->xceive_pin;
        }

        if (cx->gpio_dir == 0) {
                mutex_unlock(&cx->gpio_lock);
                return;
        }

        CX18_DEBUG_INFO("GPIO initial dir: %08x/%08x out: %08x/%08x\n",
                        cx18_read_reg(cx, CX18_REG_GPIO_DIR1),
                        cx18_read_reg(cx, CX18_REG_GPIO_DIR2),
                        cx18_read_reg(cx, CX18_REG_GPIO_OUT1),
                        cx18_read_reg(cx, CX18_REG_GPIO_OUT2));

        gpio_write(cx);
        mutex_unlock(&cx->gpio_lock);
}

int cx18_gpio_register(struct cx18 *cx, u32 hw)
{
        struct v4l2_subdev *sd;
        const struct v4l2_subdev_ops *ops;
        char *str;

        switch (hw) {
        case CX18_HW_GPIO_MUX:
                sd = &cx->sd_gpiomux;
                ops = &gpiomux_ops;
                str = "gpio-mux";
                break;
        case CX18_HW_GPIO_RESET_CTRL:
                sd = &cx->sd_resetctrl;
                ops = &resetctrl_ops;
                str = "gpio-reset-ctrl";
                break;
        default:
                return -EINVAL;
        }

        v4l2_subdev_init(sd, ops);
        v4l2_set_subdevdata(sd, cx);
        snprintf(sd->name, sizeof(sd->name), "%s %s", cx->v4l2_dev.name, str);
        sd->grp_id = hw;
        return v4l2_device_register_subdev(&cx->v4l2_dev, sd);
}

void cx18_reset_ir_gpio(void *data)
{
        struct cx18 *cx = to_cx18((struct v4l2_device *)data);

        if (cx->card->gpio_i2c_slave_reset.ir_reset_mask == 0)
                return;

        CX18_DEBUG_INFO("Resetting IR microcontroller\n");

        v4l2_subdev_call(&cx->sd_resetctrl,
                         core, reset, CX18_GPIO_RESET_Z8F0811);
}
EXPORT_SYMBOL(cx18_reset_ir_gpio);
/* This symbol is exported for use by lirc_pvr150 for the IR-blaster */

/* Xceive tuner reset function */
int cx18_reset_tuner_gpio(void *dev, int component, int cmd, int value)
{
        struct i2c_algo_bit_data *algo = dev;
        struct cx18_i2c_algo_callback_data *cb_data = algo->data;
        struct cx18 *cx = cb_data->cx;

        if (cmd != XC2028_TUNER_RESET ||
            cx->card->tuners[0].tuner != TUNER_XC2028)
                return 0;

        CX18_DEBUG_INFO("Resetting XCeive tuner\n");
        return v4l2_subdev_call(&cx->sd_resetctrl,
                                core, reset, CX18_GPIO_RESET_XC2028);
}