/*-
 * Copyright (c) 2016 Emmanuel Vadot <manu@freebsd.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Allwinner Touch Sreen driver
 * Touch screen part is not done, only the thermal sensor part is.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/rman.h>
#include <sys/sysctl.h>
#include <machine/bus.h>

#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>

#define READ(_sc, _r) bus_read_4((_sc)->res[0], (_r))
#define WRITE(_sc, _r, _v) bus_write_4((_sc)->res[0], (_r), (_v))

/* Control register 0 */
#define TP_CTRL0        0x00
#define  TP_CTRL0_TACQ(x)       ((x & 0xFF) << 0)
#define  TP_CTRL0_FS_DIV(x)     ((x & 0xF) << 16)
#define  TP_CTRL0_CLK_DIV(x)    ((x & 0x3) << 20)
#define  TP_CTRL0_CLK_SELECT(x) ((x & 0x1) << 22)

/* Control register 1 */
#define TP_CTRL1        0x04
#define  TP_CTRL1_MODE_EN       (1 << 4)

/* Control register 2 */
#define TP_CTRL2        0x08

/* Control register 3 */
#define TP_CTRL3        0x0C

/* Int/FIFO control register */
#define TP_FIFOC        0x10
#define  TP_FIFOC_TEMP_IRQ_ENABLE       (1 << 18)

/* Int/FIFO status register */
#define TP_FIFOS        0x14
#define  TP_FIFOS_TEMP_IRQ_PENDING      (1 << 18)

/* Temperature Period Register */
#define TP_TPR          0x18
#define  TP_TPR_TEMP_EN         (1 << 16)
#define  TP_TPR_TEMP_PERIOD(x)  (x << 0)

/* Common data register */
#define TP_CDAT         0x1C

/* Temperature data register */
#define TEMP_DATA       0x20

/* TP Data register*/
#define TP_DATA         0x24

/* TP IO config register */
#define TP_IO_CONFIG    0x28

/* TP IO port data register */
#define TP_IO_DATA      0x2C

struct aw_ts_softc {
        device_t                dev;
        struct resource *       res[2];
        void *                  intrhand;
        int                     temp_data;
        int                     temp_offset;
        int                     temp_step;
};

static struct resource_spec aw_ts_spec[] = {
        { SYS_RES_MEMORY,       0,      RF_ACTIVE },
        { SYS_RES_IRQ,          0,      RF_ACTIVE | RF_SHAREABLE },
        { -1, 0 }
};

#define A10_TS  1
#define A13_TS  2

#define AW_TS_TEMP_SYSCTL       1

static struct ofw_compat_data compat_data[] = {
        {"allwinner,sun4i-a10-ts", A10_TS},
        {"allwinner,sun5i-a13-ts", A13_TS},
        {NULL,             0}
};

static void
aw_ts_intr(void *arg)
{
        struct aw_ts_softc *sc;
        int val;

        sc= (struct aw_ts_softc *)arg;

        val = READ(sc, TP_FIFOS);
        if (val & TP_FIFOS_TEMP_IRQ_PENDING) {
                /* Convert the value to millicelsius then millikelvin */
                sc->temp_data = (READ(sc, TEMP_DATA) * sc->temp_step - sc->temp_offset)
                        + 273150;
        }

        WRITE(sc, TP_FIFOS, val);
}

static int
aw_ts_probe(device_t dev)
{

        if (!ofw_bus_status_okay(dev))
                return (ENXIO);

        if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
                return (ENXIO);

        device_set_desc(dev, "Allwinner Touch Screen controller");
        return (BUS_PROBE_DEFAULT);
}

static int
aw_ts_attach(device_t dev)
{
        struct aw_ts_softc *sc;

        sc = device_get_softc(dev);
        sc->dev = dev;

        if (bus_alloc_resources(dev, aw_ts_spec, sc->res) != 0) {
                device_printf(dev, "could not allocate memory resource\n");
                return (ENXIO);
        }

        if (bus_setup_intr(dev, sc->res[1],
            INTR_TYPE_MISC | INTR_MPSAFE, NULL, aw_ts_intr, sc,
            &sc->intrhand)) {
                bus_release_resources(dev, aw_ts_spec, sc->res);
                device_printf(dev, "cannot setup interrupt handler\n");
                return (ENXIO);
        }

        /*
         * Thoses magic values were taken from linux which take them from
         * the allwinner SDK or found them by deduction
         */
        switch (ofw_bus_search_compatible(dev, compat_data)->ocd_data) {
        case A10_TS:
                sc->temp_offset = 257000;
                sc->temp_step = 133;
                break;
        case A13_TS:
                sc->temp_offset = 144700;
                sc->temp_step = 100;
                break;
        }

        /* Enable clock and set divisers */
        WRITE(sc, TP_CTRL0, TP_CTRL0_CLK_SELECT(0) |
          TP_CTRL0_CLK_DIV(2) |
          TP_CTRL0_FS_DIV(7) |
          TP_CTRL0_TACQ(63));

        /* Enable TS module */
        WRITE(sc, TP_CTRL1, TP_CTRL1_MODE_EN);

        /* Enable Temperature, period is ~2s */
        WRITE(sc, TP_TPR, TP_TPR_TEMP_EN | TP_TPR_TEMP_PERIOD(1953));

        /* Enable temp irq */
        WRITE(sc, TP_FIFOC, TP_FIFOC_TEMP_IRQ_ENABLE);

        /* Add sysctl */
        SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
            SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
            OID_AUTO, "temperature",
            CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_NEEDGIANT,
            &sc->temp_data, 0, sysctl_handle_int,
            "IK3", "CPU Temperature");

        return (0);
}

static device_method_t aw_ts_methods[] = {
        DEVMETHOD(device_probe, aw_ts_probe),
        DEVMETHOD(device_attach, aw_ts_attach),

        DEVMETHOD_END
};

static driver_t aw_ts_driver = {
        "aw_ts",
        aw_ts_methods,
        sizeof(struct aw_ts_softc),
};

DRIVER_MODULE(aw_ts, simplebus, aw_ts_driver, 0, 0);