// SPDX-License-Identifier: GPL-2.0-only
/*
 * Platform device driver for devices with MCU support.
 *
 * Copyright (C) 2022 Google LLC
 */

#include <linux/interrupt.h>
#include <linux/moduleparam.h>
#include <linux/of_irq.h>

#include <gcip/iif/iif-manager.h>

#include "gxp-config.h"
#include "gxp-internal.h"
#include "gxp-mcu-fs.h"
#include "gxp-mcu-platform.h"
#include "gxp-mcu.h"
#include "gxp-usage-stats.h"
#include "gxp-vd.h"

#if HAS_TPU_EXT
#include <soc/google/tpu-ext.h>
#endif

#if IS_ENABLED(CONFIG_GXP_TEST)
char *gxp_work_mode_name = "mcu";
#else
static char *gxp_work_mode_name = "mcu";
#endif

module_param_named(work_mode, gxp_work_mode_name, charp, 0660);

static char *chip_rev = "a0";
module_param(chip_rev, charp, 0660);

static int allocate_vmbox(struct gxp_dev *gxp, struct gxp_virtual_device *vd)
{
	struct gxp_kci *kci = &(gxp_mcu_of(gxp)->kci);
	int client_id, ret;

	if (vd->is_secure)
		client_id = SECURE_CLIENT_ID;
	else
		client_id = vd->domain->pasid;

	ret = gxp_kci_allocate_vmbox(kci, client_id, vd->num_cores,
				     vd->slice_index, vd->first_open);
	if (ret) {
		dev_err(gxp->dev,
			"Failed to allocate VMBox for client %d, TPU client %d: %d",
			client_id, vd->tpu_client_id, ret);
		return ret;
	}

	vd->client_id = client_id;
	vd->first_open = false;

	return 0;
}

static int gxp_mcu_link_offload_vmbox(struct gxp_dev *gxp,
				      struct gxp_virtual_device *vd,
				      u32 offload_client_id,
				      u8 offload_chip_type)
{
	struct gxp_kci *kci = &(gxp_mcu_of(gxp)->kci);
	int ret;

	ret = gxp_kci_link_unlink_offload_vmbox(
		kci, vd->client_id, offload_client_id, offload_chip_type, true);
	if (ret) {
		dev_err(gxp->dev,
			"Failed to link offload VMBox for client %d, offload client %u, offload chip type %d: %d",
			vd->client_id, offload_client_id, offload_chip_type,
			ret);
		goto out;
	}

	vd->tpu_linked = true;
out:
	return ret;
}

static int gxp_mcu_platform_after_vd_block_ready(struct gxp_dev *gxp,
						 struct gxp_virtual_device *vd)
{
	int ret;

	if (gxp_is_direct_mode(gxp))
		return 0;

	ret = allocate_vmbox(gxp, vd);
	if (ret)
		return ret;

	if (vd->tpu_client_id >= 0) {
		ret = gxp_mcu_link_offload_vmbox(
			gxp, vd, vd->tpu_client_id,
			GCIP_KCI_OFFLOAD_CHIP_TYPE_TPU);
		if (ret)
			goto err_release_vmbox;
	}

	return 0;

err_release_vmbox:
	gxp_vd_release_vmbox(gxp, vd);
	return ret;
}

static void
gxp_mcu_platform_before_vd_block_unready(struct gxp_dev *gxp,
					 struct gxp_virtual_device *vd)
{
	if (gxp_is_direct_mode(gxp))
		return;
	if (vd->client_id < 0 || vd->mcu_crashed)
		return;
	gxp_vd_release_vmbox(gxp, vd);
}

static int gxp_mcu_pm_after_blk_on(struct gxp_dev *gxp)
{
	struct gxp_mcu_firmware *mcu_fw = gxp_mcu_firmware_of(gxp);

	if (gxp_is_direct_mode(gxp))
		return 0;
	return gxp_mcu_firmware_run(mcu_fw);
}

static void gxp_mcu_pm_before_blk_off(struct gxp_dev *gxp)
{
	struct gxp_kci *kci = &(gxp_mcu_of(gxp)->kci);
	struct gxp_mcu_firmware *mcu_fw = gxp_mcu_firmware_of(gxp);

	if (gxp_is_direct_mode(gxp))
		return;
	if (mcu_fw->status == GCIP_FW_VALID)
		gxp_kci_update_usage_locked(kci);
	gxp_mcu_firmware_stop(mcu_fw);
}

#if HAS_TPU_EXT

static int get_tpu_client_id(struct gxp_client *client, bool is_secure)
{
	struct gxp_dev *gxp = client->gxp;
	struct edgetpu_ext_offload_info offload_info;
	struct edgetpu_ext_client_info tpu_info = {
		.tpu_file = client->tpu_file,
		.flags = is_secure ? EDGETPU_EXT_SECURE_CLIENT : 0,
	};
	int ret;

	ret = edgetpu_ext_driver_cmd(gxp->tpu_dev.dev,
				     EDGETPU_EXTERNAL_CLIENT_TYPE_DSP,
				     START_OFFLOAD, &tpu_info, &offload_info);
	if (ret)
		return ret;

	return offload_info.client_id;
}

static int gxp_mcu_after_map_tpu_mbx_queue(struct gxp_dev *gxp,
					   struct gxp_client *client)
{
	struct gxp_virtual_device *vd = client->vd;
	int tpu_client_id = -1, ret;

	if (gxp_is_direct_mode(gxp))
		return 0;

	tpu_client_id = get_tpu_client_id(client, vd->is_secure);
	if (tpu_client_id < 0) {
		dev_err(gxp->dev, "Failed to get a TPU client ID: %d",
			tpu_client_id);
		return tpu_client_id;
	}

	if (vd->client_id >= 0) {
		ret = gxp_mcu_link_offload_vmbox(
			gxp, vd, tpu_client_id, GCIP_KCI_OFFLOAD_CHIP_TYPE_TPU);
		if (ret)
			return ret;
	}

	vd->tpu_client_id = tpu_client_id;

	return 0;
}

static void gxp_mcu_before_unmap_tpu_mbx_queue(struct gxp_dev *gxp, struct gxp_client *client)
{
	struct gxp_virtual_device *vd = client->vd;

	gxp_vd_unlink_offload_vmbox(gxp, vd, vd->tpu_client_id, GCIP_KCI_OFFLOAD_CHIP_TYPE_TPU);
	vd->tpu_client_id = -1;
}

#endif /* HAS_TPU_EXT */

static irqreturn_t mcu_wdg_irq_handler(int irq, void *arg)
{
	struct gxp_dev *gxp = arg;
	u32 wdg_control_val;

	/* Clear the interrupt and disable the WDG. */
	wdg_control_val = gxp_read_32(gxp, GXP_REG_WDOG_CONTROL);
	wdg_control_val |= BIT(GXP_WDG_INT_CLEAR_BIT);
	wdg_control_val &= ~BIT(GXP_WDG_ENABLE_BIT);
	gxp_write_32(gxp, GXP_REG_WDOG_CONTROL, wdg_control_val);

	return IRQ_WAKE_THREAD;
}

static irqreturn_t mcu_wdg_threaded_handler(int irq, void *arg)
{
	struct gxp_dev *gxp = arg;

	gxp_mcu_firmware_crash_handler(gxp, GCIP_FW_CRASH_HW_WDG_TIMEOUT);

	return IRQ_HANDLED;
}

static int gxp_mcu_register_wdg_irq(struct gxp_dev *gxp)
{
	struct device *dev = gxp->dev;
	unsigned int wdg_virq;
	int ret;

	wdg_virq = irq_of_parse_and_map(dev->of_node, GXP_WDG_DT_IRQ_INDEX);
	if (!wdg_virq) {
		dev_warn(dev,
			 "Unable to parse interrupt for HW WDG from the DT");
		return 0;
	}
	ret = devm_request_threaded_irq(dev, wdg_virq, mcu_wdg_irq_handler,
					mcu_wdg_threaded_handler,
					/*flags=*/0, "aurora_mcu_wdg",
					(void *)gxp);
	if (ret)
		dev_err(dev, "Unable to register MCU WDG IRQ: %d\n", ret);

	return ret;
}

struct gxp_mcu *gxp_mcu_of(struct gxp_dev *gxp)
{
	return &(to_mcu_dev(gxp)->mcu);
}

struct gxp_mcu_firmware *gxp_mcu_firmware_of(struct gxp_dev *gxp)
{
	return &(gxp_mcu_of(gxp)->fw);
}

bool gxp_is_direct_mode(struct gxp_dev *gxp)
{
	struct gxp_mcu_dev *mcu_dev = to_mcu_dev(gxp);

	return mcu_dev->mode == DIRECT;
}

enum gxp_chip_revision gxp_get_chip_revision(struct gxp_dev *gxp)
{
	if (!strcmp(chip_rev, "a0"))
		return GXP_CHIP_A0;
	if (!strcmp(chip_rev, "b0"))
		return GXP_CHIP_B0;
	return GXP_CHIP_ANY;
}

int gxp_mcu_platform_after_probe(struct gxp_dev *gxp)
{
	int ret;

	if (gxp_is_direct_mode(gxp))
		return 0;

	ret = gxp_mcu_register_wdg_irq(gxp);
	if (ret)
		return ret;

	gxp->iif_mgr = iif_manager_init(gxp->dev->of_node);
	if (IS_ERR(gxp->iif_mgr)) {
		dev_err(gxp->dev, "Failed to init IIF manager: %ld", PTR_ERR(gxp->iif_mgr));
		gxp->iif_mgr = NULL;
	}

	gxp_usage_stats_init(gxp);
	return gxp_mcu_init(gxp, gxp_mcu_of(gxp));
}

void gxp_mcu_platform_before_remove(struct gxp_dev *gxp)
{
	if (gxp_is_direct_mode(gxp))
		return;

	gxp_mcu_exit(gxp_mcu_of(gxp));
	gxp_usage_stats_exit(gxp);

	if (gxp->iif_mgr)
		iif_manager_put(gxp->iif_mgr);
}

void gxp_mcu_dev_init(struct gxp_mcu_dev *mcu_dev)
{
	struct gxp_dev *gxp = &mcu_dev->gxp;

	mcu_dev->mode = gxp_dev_parse_work_mode(gxp_work_mode_name);
	gxp->after_probe = gxp_mcu_platform_after_probe;
	gxp->before_remove = gxp_mcu_platform_before_remove;
	gxp->handle_ioctl = gxp_mcu_ioctl;
	gxp->handle_mmap = gxp_mcu_mmap;
	gxp->after_vd_block_ready = gxp_mcu_platform_after_vd_block_ready;
	gxp->before_vd_block_unready = gxp_mcu_platform_before_vd_block_unready;
	gxp->pm_after_blk_on = gxp_mcu_pm_after_blk_on;
	gxp->pm_before_blk_off = gxp_mcu_pm_before_blk_off;
#if HAS_TPU_EXT
	gxp->after_map_tpu_mbx_queue = gxp_mcu_after_map_tpu_mbx_queue;
	gxp->before_unmap_tpu_mbx_queue = gxp_mcu_before_unmap_tpu_mbx_queue;
#endif
}

enum gxp_work_mode gxp_dev_parse_work_mode(const char *work_mode)
{
	if (!strcmp(work_mode, "mcu"))
		return MCU;
	return DIRECT;
}