/* $NetBSD: exynos_dwcmmc.c,v 1.15 2021/03/14 08:16:57 skrll Exp $ */

/*-
 * Copyright (c) 2015 Jared D. McNeill <jmcneill@invisible.ca>
 * All rights reserved.
 *
 * 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 ``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 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: exynos_dwcmmc.c,v 1.15 2021/03/14 08:16:57 skrll Exp $");

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/device.h>
#include <sys/intr.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mutex.h>
#include <sys/condvar.h>

#include <arm/samsung/exynos_var.h>

#include <dev/ic/dwc_mmc_reg.h>
#include <dev/ic/dwc_mmc_var.h>
#include <dev/fdt/fdtvar.h>

#define MPS_BEGIN       0x200
#define MPS_END         0x204
#define MPS_CTRL        0x20c
#define  MPS_CTRL_SECURE_WRITE          __BIT(6)
#define  MPS_CTRL_NON_SECURE_READ       __BIT(5)
#define  MPS_CTRL_NON_SECURE_WRITE      __BIT(4)
#define  MPS_CTRL_VALID                 __BIT(0)

static int      exynos_dwcmmc_match(device_t, cfdata_t, void *);
static void     exynos_dwcmmc_attach(device_t, device_t, void *);

static int      exynos_dwcmmc_card_detect(struct dwc_mmc_softc *);
static int      exynos_dwcmmc_bus_clock(struct dwc_mmc_softc *, int);

struct exynos_dwcmmc_softc {
        struct dwc_mmc_softc    sc;
        struct clk              *sc_clk_biu;
        struct clk              *sc_clk_ciu;
        struct fdtbus_gpio_pin  *sc_pin_cd;
        u_int                   sc_ciu_div;
};

CFATTACH_DECL_NEW(exynos_dwcmmc, sizeof(struct exynos_dwcmmc_softc),
        exynos_dwcmmc_match, exynos_dwcmmc_attach, NULL, NULL);

static const struct device_compatible_entry compat_data[] = {
                                                /* disable encryption mode? */
        { .compat = "samsung,exynos5250-dw-mshc",       .value = 0 },
        { .compat = "samsung,exynos5420-dw-mshc-smu",   .value = 1 },
        { .compat = "samsung,exynos5420-dw-mshc",       .value = 0 },
        DEVICE_COMPAT_EOL
};

static int
exynos_dwcmmc_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
exynos_dwcmmc_attach(device_t parent, device_t self, void *aux)
{
        struct exynos_dwcmmc_softc *esc = device_private(self);
        struct dwc_mmc_softc *sc = &esc->sc;
        struct fdt_attach_args * const faa = aux;
        const struct device_compatible_entry *dce;
        const int phandle = faa->faa_phandle;
        char intrstr[128];
        bus_addr_t addr;
        bus_size_t size;
        int error;

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

        if (of_getprop_uint32(phandle, "samsung,dw-mshc-ciu-div", &esc->sc_ciu_div)) {
                aprint_error(": missing samsung,dw-mshc-ciu-div property\n");
                return;
        }

        esc->sc_clk_biu = fdtbus_clock_get(phandle, "biu");
        if (esc->sc_clk_biu == NULL) {
                aprint_error(": couldn't get clock biu\n");
                return;
        }
        esc->sc_clk_ciu = fdtbus_clock_get(phandle, "ciu");
        if (esc->sc_clk_ciu == NULL) {
                aprint_error(": couldn't get clock ciu\n");
                return;
        }

        error = clk_enable(esc->sc_clk_biu);
        if (error) {
                aprint_error(": couldn't enable clock biu: %d\n", error);
                return;
        }
        error = clk_enable(esc->sc_clk_ciu);
        if (error) {
                aprint_error(": couldn't enable clock ciu: %d\n", error);
                return;
        }

        dce = of_compatible_lookup(faa->faa_phandle, compat_data);
        KASSERT(dce != NULL);

        sc->sc_dev = self;
        sc->sc_bst = faa->faa_bst;
        sc->sc_dmat = faa->faa_dmat;
        sc->sc_intr_cardmask = DWC_MMC_INT_SDIO_INT(8);
        error = bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh);
        if (error) {
                aprint_error(": couldn't map %#" PRIxBUSADDR ": %d\n",
                    addr, error);
                return;
        }

        sc->sc_clock_freq = clk_get_rate(esc->sc_clk_ciu) / (esc->sc_ciu_div + 1);
        of_getprop_uint32(phandle, "fifo-depth", &sc->sc_fifo_depth);
        sc->sc_flags = DWC_MMC_F_DMA;
        sc->sc_bus_clock = exynos_dwcmmc_bus_clock;

        esc->sc_pin_cd = fdtbus_gpio_acquire(phandle, "cd-gpios",
            GPIO_PIN_INPUT);
        if (esc->sc_pin_cd)
                sc->sc_card_detect = exynos_dwcmmc_card_detect;

        aprint_naive("\n");
        aprint_normal(": MHS (%u Hz)\n", sc->sc_clock_freq);

        if (!fdtbus_intr_str(phandle, 0, intrstr, sizeof(intrstr))) {
                aprint_error_dev(self, "failed to decode interrupt\n");
                return;
        }

        if (dwc_mmc_init(sc) != 0)
                return;

        sc->sc_ih = fdtbus_intr_establish_xname(phandle, 0, IPL_BIO, 0,
            dwc_mmc_intr, sc, device_xname(self));
        if (sc->sc_ih == NULL) {
                aprint_error_dev(self, "couldn't establish interrupt on %s\n",
                    intrstr);
                return;
        }
        aprint_normal_dev(self, "interrupting on %s\n", intrstr);

        /* Disable encryption mode */
        if (dce->value != 0) {
                bus_space_write_4(sc->sc_bst, sc->sc_bsh, MPS_BEGIN, 0);
                bus_space_write_4(sc->sc_bst, sc->sc_bsh, MPS_END, ~0U);
                bus_space_write_4(sc->sc_bst, sc->sc_bsh, MPS_CTRL,
                    MPS_CTRL_NON_SECURE_READ | MPS_CTRL_NON_SECURE_WRITE |
                    MPS_CTRL_SECURE_WRITE | MPS_CTRL_VALID);
        }
}

static int
exynos_dwcmmc_card_detect(struct dwc_mmc_softc *sc)
{
        struct exynos_dwcmmc_softc *esc = device_private(sc->sc_dev);

        KASSERT(esc->sc_pin_cd != NULL);

        return fdtbus_gpio_read(esc->sc_pin_cd);
}

static int
exynos_dwcmmc_bus_clock(struct dwc_mmc_softc *sc, int rate)
{
        struct exynos_dwcmmc_softc *esc = device_private(sc->sc_dev);
        const int ciu_div = esc->sc_ciu_div + 1;
        int error;

        error = clk_set_rate(esc->sc_clk_ciu, 1000 * rate * ciu_div);
        if (error != 0) {
                aprint_error_dev(sc->sc_dev, "failed to set rate to %u Hz: %d\n",
                    rate * ciu_div * 1000, error);
                return error;
        }

        sc->sc_clock_freq = clk_get_rate(esc->sc_clk_ciu) / ciu_div;

        aprint_debug_dev(sc->sc_dev, "set clock rate to %u Hz (target %u Hz)\n",
            sc->sc_clock_freq, rate * 1000);

        return 0;
}