/*      $NetBSD: meson6_timer.c,v 1.2 2021/01/27 03:10:18 thorpej Exp $ */

/*-
 * Copyright (c) 2019 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Nick Hudson
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: meson6_timer.c,v 1.2 2021/01/27 03:10:18 thorpej Exp $");

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/device.h>
#include <sys/systm.h>
#include <sys/timetc.h>

#include <dev/fdt/fdtvar.h>

static int      meson6_timer_match(device_t, cfdata_t, void *);
static void     meson6_timer_attach(device_t, device_t, void *);

struct meson6_timer_softc {
        device_t                sc_dev;
        bus_space_tag_t         sc_bst;
        bus_space_handle_t      sc_bsh;

        struct timecounter sc_tc;
};

CFATTACH_DECL_NEW(meson6_timer, sizeof(struct meson6_timer_softc),
    meson6_timer_match, meson6_timer_attach, NULL, NULL);

#define TIMER_READ(sc, reg)                     \
    bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
#define TIMER_WRITE(sc, reg, val)               \
    bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))

#define MESON_TIMER_MUX                                 0x00
#define  MESON_TIMER_MUX_TIMERD_EN                      __BIT(19)
#define  MESON_TIMER_MUX_TIMERC_EN                      __BIT(18)
#define  MESON_TIMER_MUX_TIMERB_EN                      __BIT(17)
#define  MESON_TIMER_MUX_TIMERA_EN                      __BIT(16)
#define  MESON_TIMER_MUX_TIMERD_MODE                    __BIT(15)
#define  MESON_TIMER_MUX_TIMERC_MODE                    __BIT(14)
#define  MESON_TIMER_MUX_TIMERB_MODE                    __BIT(13)
#define  MESON_TIMER_MUX_TIMERA_MODE                    __BIT(12)
#define  MESON_TIMER_MUX_TIMERE_INPUT_CLOCK_MASK        __BITS(10, 8)
#define   MESON_TIMER_MUX_TIMERE_INPUT_CLOCK_SYSTEM_CLOCK       0x0
#define   MESON_TIMER_MUX_TIMERE_INPUT_CLOCK_1US                0x1
#define   MESON_TIMER_MUX_TIMERE_INPUT_CLOCK_10US               0x2
#define   MESON_TIMER_MUX_TIMERE_INPUT_CLOCK_100US              0x3
#define   MESON_TIMER_MUX_TIMERE_INPUT_CLOCK_1MS                0x4
#define  MESON_TIMER_MUX_TIMERD_INPUT_CLOCK_MASK        __BITS(7, 6)
#define  MESON_TIMER_MUX_TIMERC_INPUT_CLOCK_MASK        __BITS(5, 4)
#define  MESON_TIMER_MUX_TIMERB_INPUT_CLOCK_MASK        __BITS(3, 2)
#define  MESON_TIMER_MUX_TIMERA_INPUT_CLOCK_MASK        __BITS(1, 0)
#define   MESON_TIMER_MUX_TIMERABCD_INPUT_CLOCK_1US             0x0
#define   MESON_TIMER_MUX_TIMERABCD_INPUT_CLOCK_10US            0x1
#define   MESON_TIMER_MUX_TIMERABCD_INPUT_CLOCK_100US           0x2
#define   MESON_TIMER_MUX_TIMERABCD_INPUT_CLOCK_1MS             0x3

#define MESON_TIMERA                                    0x04
#define MESON_TIMERB                                    0x08
#define MESON_TIMERC                                    0x0c
#define MESON_TIMERD                                    0x10
#define MESON_TIMERE                                    0x14

static u_int
meson6_timer_get_timecount(struct timecounter *tc)
{
        struct meson6_timer_softc * const sc = tc->tc_priv;

        return TIMER_READ(sc, MESON_TIMERE);
}

static const struct device_compatible_entry compat_data[] = {
        { .compat = "amlogic,meson6-timer" },
        DEVICE_COMPAT_EOL
};

static int
meson6_timer_match(device_t parent, cfdata_t cf, void *aux)
{
        struct fdt_attach_args * const faa = aux;

        return of_compatible_match(faa->faa_phandle, compat_data);
}

static void
meson6_timer_attach(device_t parent, device_t self, void *aux)
{
        struct meson6_timer_softc * const sc = device_private(self);
        struct fdt_attach_args * const faa = aux;
        const int phandle = faa->faa_phandle;
        bus_addr_t addr;
        bus_size_t size;

        if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
                aprint_error(": couldn't get registers\n");
                return;
        }

        sc->sc_dev = self;
        sc->sc_bst = faa->faa_bst;
        if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) {
                aprint_error(": couldn't map registers\n");
                return;
        }

        /* Enable clocks */
        struct clk *clk;
        for (int i = 0; (clk = fdtbus_clock_get_index(phandle, i)); i++) {
                if (clk_enable(clk) != 0) {
                        aprint_error(": failed to enable clock #%d\n", i);
                        return;
                }
        }

        aprint_naive("\n");
        aprint_normal(": Timers\n");

        uint32_t mask = TIMER_READ(sc, MESON_TIMER_MUX);
        mask &= ~MESON_TIMER_MUX_TIMERE_INPUT_CLOCK_MASK;
        mask |= __SHIFTIN(MESON_TIMER_MUX_TIMERE_INPUT_CLOCK_1US, MESON_TIMER_MUX_TIMERE_INPUT_CLOCK_MASK);

        TIMER_WRITE(sc, MESON_TIMER_MUX, mask);

        /* Timecounter setup */
        struct timecounter *tc = &sc->sc_tc;
        tc->tc_get_timecount = meson6_timer_get_timecount;
        tc->tc_counter_mask = ~0u;
        tc->tc_frequency = 1000000;
        tc->tc_name = "Timer E";
        tc->tc_quality = 500;
        tc->tc_priv = sc;
        tc_init(tc);
}