/* $NetBSD: tegra_drm.c,v 1.16 2022/04/21 21:22:25 andvar 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: tegra_drm.c,v 1.16 2022/04/21 21:22:25 andvar 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/conf.h>

#include <uvm/uvm_extern.h>
#include <uvm/uvm_device.h>

#include <drm/drm_drv.h>
#include <drm/drm_encoder.h>

#include <arm/nvidia/tegra_reg.h>
#include <arm/nvidia/tegra_var.h>
#include <arm/nvidia/tegra_drm.h>

#include <dev/fdt/fdtvar.h>

static int      tegra_drm_match(device_t, cfdata_t, void *);
static void     tegra_drm_attach(device_t, device_t, void *);

static int      tegra_drm_load(struct drm_device *, unsigned long);
static void     tegra_drm_unload(struct drm_device *);

static void     tegra_drm_task_work(struct work *, void *);

static struct drm_driver tegra_drm_driver = {
        .driver_features = DRIVER_MODESET | DRIVER_GEM,
        .dev_priv_size = 0,
        .load = tegra_drm_load,
        .unload = tegra_drm_unload,

        .gem_free_object = drm_gem_cma_free_object,
        .mmap_object = drm_gem_or_legacy_mmap_object,
        .gem_uvm_ops = &drm_gem_cma_uvm_ops,

        .dumb_create = drm_gem_cma_dumb_create,

        .get_vblank_counter = tegra_drm_get_vblank_counter,
        .enable_vblank = tegra_drm_enable_vblank,
        .disable_vblank = tegra_drm_disable_vblank,

        .name = DRIVER_NAME,
        .desc = DRIVER_DESC,
        .date = DRIVER_DATE,
        .major = DRIVER_MAJOR,
        .minor = DRIVER_MINOR,
        .patchlevel = DRIVER_PATCHLEVEL,
};

CFATTACH_DECL_NEW(tegra_drm, sizeof(struct tegra_drm_softc),
        tegra_drm_match, tegra_drm_attach, NULL, NULL);

static const struct device_compatible_entry compat_data[] = {
        { .compat = "nvidia,tegra124-host1x" },
        DEVICE_COMPAT_EOL
};

static int
tegra_drm_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 const struct device_compatible_entry hdmi_compat[] = {
        { .compat = "nvidia,tegra124-hdmi" },
        DEVICE_COMPAT_EOL
};

static const struct device_compatible_entry dc_compat[] = {
        { .compat = "nvidia,tegra124-dc" },
        DEVICE_COMPAT_EOL
};

static void
tegra_drm_attach(device_t parent, device_t self, void *aux)
{
        struct tegra_drm_softc * const sc = device_private(self);
        struct fdt_attach_args * const faa = aux;
        struct drm_driver * const driver = &tegra_drm_driver;
        prop_dictionary_t prop = device_properties(self);
        int error, node, hdmi_phandle, ddc_phandle;
        static const char * const hdmi_supplies[] = {
                "hdmi-supply", "pll-supply", "vdd-supply"
        };
        struct fdtbus_regulator *reg;
        u_int n, ndc;

        sc->sc_dev = self;
        sc->sc_dmat = faa->faa_dmat;
        sc->sc_bst = faa->faa_bst;
        sc->sc_phandle = faa->faa_phandle;
        sc->sc_task_thread = NULL;
        SIMPLEQ_INIT(&sc->sc_tasks);
        if (workqueue_create(&sc->sc_task_wq, "tegradrm",
            &tegra_drm_task_work, NULL, PRI_NONE, IPL_NONE, WQ_MPSAFE)) {
                aprint_error_dev(self, "unable to create workqueue\n");
                sc->sc_task_wq = NULL;
                return;
        }

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

        sc->sc_clk_host1x = fdtbus_clock_get_index(faa->faa_phandle, 0);
        if (sc->sc_clk_host1x == NULL) {
                aprint_error_dev(self, "couldn't get clock host1x\n");
                return;
        }
        sc->sc_rst_host1x = fdtbus_reset_get(faa->faa_phandle, "host1x");
        if (sc->sc_clk_host1x == NULL || sc->sc_rst_host1x == NULL) {
                aprint_error_dev(self, "couldn't get reset host1x\n");
                return;
        }

        ndc = 0;
        hdmi_phandle = -1;
        for (node = OF_child(faa->faa_phandle); node; node = OF_peer(node)) {
                if (of_compatible_match(node, hdmi_compat)) {
                        sc->sc_clk_hdmi = fdtbus_clock_get(node, "hdmi");
                        sc->sc_clk_hdmi_parent = fdtbus_clock_get(node,
                            "parent");
                        sc->sc_rst_hdmi = fdtbus_reset_get(node, "hdmi");
                        hdmi_phandle = node;
                } else if (of_compatible_match(node, dc_compat) &&
                           ndc < __arraycount(sc->sc_clk_dc)) {
                        sc->sc_clk_dc[ndc] = fdtbus_clock_get(node, "dc");
                        sc->sc_clk_dc_parent[ndc] = fdtbus_clock_get(node,
                            "parent");
                        sc->sc_rst_dc[ndc] = fdtbus_reset_get(node, "dc");
                        ++ndc;
                }
        }
        if (hdmi_phandle >= 0) {
                ddc_phandle = fdtbus_get_phandle(hdmi_phandle,
                    "nvidia,ddc-i2c-bus");
                if (ddc_phandle >= 0) {
                        sc->sc_ddc = fdtbus_i2c_get_tag(ddc_phandle);
                }

                sc->sc_pin_hpd = fdtbus_gpio_acquire(hdmi_phandle,
                    "nvidia,hpd-gpio", GPIO_PIN_INPUT);

                for (n = 0; n < __arraycount(hdmi_supplies); n++) {
                        const char *supply = hdmi_supplies[n];
                        reg = fdtbus_regulator_acquire(hdmi_phandle, supply);
                        if (reg == NULL) {
                                aprint_error_dev(self, "couldn't acquire %s\n",
                                    supply);
                                continue;
                        }
                        if (fdtbus_regulator_enable(reg) != 0) {
                                aprint_error_dev(self, "couldn't enable %s\n",
                                    supply);
                        }
                        fdtbus_regulator_release(reg);
                }
        }

        fdtbus_reset_assert(sc->sc_rst_host1x);
        error = clk_enable(sc->sc_clk_host1x);
        if (error) {
                aprint_error_dev(self, "couldn't enable clock host1x: %d\n",
                    error);
                return;
        }
        fdtbus_reset_deassert(sc->sc_rst_host1x);

        prop_dictionary_get_bool(prop, "force-dvi", &sc->sc_force_dvi);

        sc->sc_ddev = drm_dev_alloc(driver, sc->sc_dev);
        if (IS_ERR(sc->sc_ddev)) {
                aprint_error_dev(self, "couldn't allocate DRM device\n");
                return;
        }
        sc->sc_ddev->dev_private = sc;
        sc->sc_ddev->bst = sc->sc_bst;
        sc->sc_ddev->bus_dmat = sc->sc_dmat;
        sc->sc_ddev->dmat = sc->sc_ddev->bus_dmat;
        sc->sc_ddev->dmat_subregion_p = false;

        /*
         * Cause any tasks issued synchronously during attach to be
         * processed at the end of this function.
         */
        sc->sc_task_thread = curlwp;

        error = -drm_dev_register(sc->sc_ddev, 0);
        if (error) {
                drm_dev_put(sc->sc_ddev);
                sc->sc_ddev = NULL;
                aprint_error_dev(self, "couldn't register DRM device: %d\n",
                    error);
                goto out;
        }
        sc->sc_dev_registered = true;

        aprint_normal_dev(self, "initialized %s %d.%d.%d %s on minor %d\n",
            driver->name, driver->major, driver->minor, driver->patchlevel,
            driver->date, sc->sc_ddev->primary->index);

        /*
         * Process asynchronous tasks queued synchronously during
         * attach.  This will be for display detection to attach a
         * framebuffer, so we have the opportunity for a console device
         * to attach before autoconf has completed, in time for init(8)
         * to find that console without panicking.
         */
        while (!SIMPLEQ_EMPTY(&sc->sc_tasks)) {
                struct tegra_drm_task *const task =
                    SIMPLEQ_FIRST(&sc->sc_tasks);

                SIMPLEQ_REMOVE_HEAD(&sc->sc_tasks, tdt_u.queue);
                (*task->tdt_fn)(task);
        }

out:    /* Cause any subsequent tasks to be processed by the workqueue.  */
        atomic_store_relaxed(&sc->sc_task_thread, NULL);
}

static int
tegra_drm_load(struct drm_device *ddev, unsigned long flags)
{
        int error;

        error = tegra_drm_mode_init(ddev);
        if (error)
                goto drmerr;

        error = tegra_drm_fb_init(ddev);
        if (error)
                goto drmerr;

        return 0;

drmerr:
        drm_mode_config_cleanup(ddev);

        return error;
}

static void
tegra_drm_unload(struct drm_device *ddev)
{

        drm_mode_config_cleanup(ddev);
}

static void
tegra_drm_task_work(struct work *work, void *cookie)
{
        struct tegra_drm_task *task = container_of(work, struct tegra_drm_task,
            tdt_u.work);

        (*task->tdt_fn)(task);
}

void
tegra_task_init(struct tegra_drm_task *task,
    void (*fn)(struct tegra_drm_task *))
{

        task->tdt_fn = fn;
}

void
tegra_task_schedule(device_t self, struct tegra_drm_task *task)
{
        struct tegra_drm_softc *sc = device_private(self);

        if (atomic_load_relaxed(&sc->sc_task_thread) == curlwp)
                SIMPLEQ_INSERT_TAIL(&sc->sc_tasks, task, tdt_u.queue);
        else
                workqueue_enqueue(sc->sc_task_wq, &task->tdt_u.work, NULL);
}