/*
 * Copyright (C) STMicroelectronics SA 2015
 * Authors: Yannick Fertre <yannick.fertre@st.com>
 *          Hugues Fruchet <hugues.fruchet@st.com>
 * License terms:  GNU General Public License (GPL), version 2
 */

#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>

#include "hva.h"
#include "hva-hw.h"

/* HVA register offsets */
#define HVA_HIF_REG_RST                 0x0100U
#define HVA_HIF_REG_RST_ACK             0x0104U
#define HVA_HIF_REG_MIF_CFG             0x0108U
#define HVA_HIF_REG_HEC_MIF_CFG         0x010CU
#define HVA_HIF_REG_CFL                 0x0110U
#define HVA_HIF_FIFO_CMD                0x0114U
#define HVA_HIF_FIFO_STS                0x0118U
#define HVA_HIF_REG_SFL                 0x011CU
#define HVA_HIF_REG_IT_ACK              0x0120U
#define HVA_HIF_REG_ERR_IT_ACK          0x0124U
#define HVA_HIF_REG_LMI_ERR             0x0128U
#define HVA_HIF_REG_EMI_ERR             0x012CU
#define HVA_HIF_REG_HEC_MIF_ERR         0x0130U
#define HVA_HIF_REG_HEC_STS             0x0134U
#define HVA_HIF_REG_HVC_STS             0x0138U
#define HVA_HIF_REG_HJE_STS             0x013CU
#define HVA_HIF_REG_CNT                 0x0140U
#define HVA_HIF_REG_HEC_CHKSYN_DIS      0x0144U
#define HVA_HIF_REG_CLK_GATING          0x0148U
#define HVA_HIF_REG_VERSION             0x014CU
#define HVA_HIF_REG_BSM                 0x0150U

/* define value for version id register (HVA_HIF_REG_VERSION) */
#define VERSION_ID_MASK	0x0000FFFF

/* define values for BSM register (HVA_HIF_REG_BSM) */
#define BSM_CFG_VAL1	0x0003F000
#define BSM_CFG_VAL2	0x003F0000

/* define values for memory interface register (HVA_HIF_REG_MIF_CFG) */
#define MIF_CFG_VAL1	0x04460446
#define MIF_CFG_VAL2	0x04460806
#define MIF_CFG_VAL3	0x00000000

/* define value for HEC memory interface register (HVA_HIF_REG_MIF_CFG) */
#define HEC_MIF_CFG_VAL	0x000000C4

/*  Bits definition for clock gating register (HVA_HIF_REG_CLK_GATING) */
#define CLK_GATING_HVC	BIT(0)
#define CLK_GATING_HEC	BIT(1)
#define CLK_GATING_HJE	BIT(2)

/* fix hva clock rate */
#define CLK_RATE		300000000

/* fix delay for pmruntime */
#define AUTOSUSPEND_DELAY_MS	3

/*
 * hw encode error values
 * NO_ERROR: Success, Task OK
 * H264_BITSTREAM_OVERSIZE: VECH264 Bitstream size > bitstream buffer
 * H264_FRAME_SKIPPED: VECH264 Frame skipped (refers to CPB Buffer Size)
 * H264_SLICE_LIMIT_SIZE: VECH264 MB > slice limit size
 * H264_MAX_SLICE_NUMBER: VECH264 max slice number reached
 * H264_SLICE_READY: VECH264 Slice ready
 * TASK_LIST_FULL: HVA/FPC task list full
		   (discard latest transform command)
 * UNKNOWN_COMMAND: Transform command not known by HVA/FPC
 * WRONG_CODEC_OR_RESOLUTION: Wrong Codec or Resolution Selection
 * NO_INT_COMPLETION: Time-out on interrupt completion
 * LMI_ERR: Local Memory Interface Error
 * EMI_ERR: External Memory Interface Error
 * HECMI_ERR: HEC Memory Interface Error
 */
enum hva_hw_error {
	NO_ERROR = 0x0,
	H264_BITSTREAM_OVERSIZE = 0x2,
	H264_FRAME_SKIPPED = 0x4,
	H264_SLICE_LIMIT_SIZE = 0x5,
	H264_MAX_SLICE_NUMBER = 0x7,
	H264_SLICE_READY = 0x8,
	TASK_LIST_FULL = 0xF0,
	UNKNOWN_COMMAND = 0xF1,
	WRONG_CODEC_OR_RESOLUTION = 0xF4,
	NO_INT_COMPLETION = 0x100,
	LMI_ERR = 0x101,
	EMI_ERR = 0x102,
	HECMI_ERR = 0x103,
};

static irqreturn_t hva_hw_its_interrupt(int irq, void *data)
{
	struct hva_dev *hva = data;

	/* read status registers */
	hva->sts_reg = readl_relaxed(hva->regs + HVA_HIF_FIFO_STS);
	hva->sfl_reg = readl_relaxed(hva->regs + HVA_HIF_REG_SFL);

	/* acknowledge interruption */
	writel_relaxed(0x1, hva->regs + HVA_HIF_REG_IT_ACK);

	return IRQ_WAKE_THREAD;
}

static irqreturn_t hva_hw_its_irq_thread(int irq, void *arg)
{
	struct hva_dev *hva = arg;
	struct device *dev = hva_to_dev(hva);
	u32 status = hva->sts_reg & 0xFF;
	u8 ctx_id = 0;
	struct hva_ctx *ctx = NULL;

	dev_dbg(dev, "%s     %s: status: 0x%02x fifo level: 0x%02x\n",
		HVA_PREFIX, __func__, hva->sts_reg & 0xFF, hva->sfl_reg & 0xF);

	/*
	 * status: task_id[31:16] client_id[15:8] status[7:0]
	 * the context identifier is retrieved from the client identifier
	 */
	ctx_id = (hva->sts_reg & 0xFF00) >> 8;
	if (ctx_id >= HVA_MAX_INSTANCES) {
		dev_err(dev, "%s     %s: bad context identifier: %d\n",
			ctx->name, __func__, ctx_id);
		ctx->hw_err = true;
		goto out;
	}

	ctx = hva->instances[ctx_id];
	if (!ctx)
		goto out;

	switch (status) {
	case NO_ERROR:
		dev_dbg(dev, "%s     %s: no error\n",
			ctx->name, __func__);
		ctx->hw_err = false;
		break;
	case H264_SLICE_READY:
		dev_dbg(dev, "%s     %s: h264 slice ready\n",
			ctx->name, __func__);
		ctx->hw_err = false;
		break;
	case H264_FRAME_SKIPPED:
		dev_dbg(dev, "%s     %s: h264 frame skipped\n",
			ctx->name, __func__);
		ctx->hw_err = false;
		break;
	case H264_BITSTREAM_OVERSIZE:
		dev_err(dev, "%s     %s:h264 bitstream oversize\n",
			ctx->name, __func__);
		ctx->hw_err = true;
		break;
	case H264_SLICE_LIMIT_SIZE:
		dev_err(dev, "%s     %s: h264 slice limit size is reached\n",
			ctx->name, __func__);
		ctx->hw_err = true;
		break;
	case H264_MAX_SLICE_NUMBER:
		dev_err(dev, "%s     %s: h264 max slice number is reached\n",
			ctx->name, __func__);
		ctx->hw_err = true;
		break;
	case TASK_LIST_FULL:
		dev_err(dev, "%s     %s:task list full\n",
			ctx->name, __func__);
		ctx->hw_err = true;
		break;
	case UNKNOWN_COMMAND:
		dev_err(dev, "%s     %s: command not known\n",
			ctx->name, __func__);
		ctx->hw_err = true;
		break;
	case WRONG_CODEC_OR_RESOLUTION:
		dev_err(dev, "%s     %s: wrong codec or resolution\n",
			ctx->name, __func__);
		ctx->hw_err = true;
		break;
	default:
		dev_err(dev, "%s     %s: status not recognized\n",
			ctx->name, __func__);
		ctx->hw_err = true;
		break;
	}
out:
	complete(&hva->interrupt);

	return IRQ_HANDLED;
}

static irqreturn_t hva_hw_err_interrupt(int irq, void *data)
{
	struct hva_dev *hva = data;

	/* read status registers */
	hva->sts_reg = readl_relaxed(hva->regs + HVA_HIF_FIFO_STS);
	hva->sfl_reg = readl_relaxed(hva->regs + HVA_HIF_REG_SFL);

	/* read error registers */
	hva->lmi_err_reg = readl_relaxed(hva->regs + HVA_HIF_REG_LMI_ERR);
	hva->emi_err_reg = readl_relaxed(hva->regs + HVA_HIF_REG_EMI_ERR);
	hva->hec_mif_err_reg = readl_relaxed(hva->regs +
					     HVA_HIF_REG_HEC_MIF_ERR);

	/* acknowledge interruption */
	writel_relaxed(0x1, hva->regs + HVA_HIF_REG_IT_ACK);

	return IRQ_WAKE_THREAD;
}

static irqreturn_t hva_hw_err_irq_thread(int irq, void *arg)
{
	struct hva_dev *hva = arg;
	struct device *dev = hva_to_dev(hva);
	u8 ctx_id = 0;
	struct hva_ctx *ctx;

	dev_dbg(dev, "%s     status: 0x%02x fifo level: 0x%02x\n",
		HVA_PREFIX, hva->sts_reg & 0xFF, hva->sfl_reg & 0xF);

	/*
	 * status: task_id[31:16] client_id[15:8] status[7:0]
	 * the context identifier is retrieved from the client identifier
	 */
	ctx_id = (hva->sts_reg & 0xFF00) >> 8;
	if (ctx_id >= HVA_MAX_INSTANCES) {
		dev_err(dev, "%s     bad context identifier: %d\n", HVA_PREFIX,
			ctx_id);
		goto out;
	}

	ctx = hva->instances[ctx_id];
	if (!ctx)
		goto out;

	if (hva->lmi_err_reg) {
		dev_err(dev, "%s     local memory interface error: 0x%08x\n",
			ctx->name, hva->lmi_err_reg);
		ctx->hw_err = true;
	}

	if (hva->lmi_err_reg) {
		dev_err(dev, "%s     external memory interface error: 0x%08x\n",
			ctx->name, hva->emi_err_reg);
		ctx->hw_err = true;
	}

	if (hva->hec_mif_err_reg) {
		dev_err(dev, "%s     hec memory interface error: 0x%08x\n",
			ctx->name, hva->hec_mif_err_reg);
		ctx->hw_err = true;
	}
out:
	complete(&hva->interrupt);

	return IRQ_HANDLED;
}

static unsigned long int hva_hw_get_ip_version(struct hva_dev *hva)
{
	struct device *dev = hva_to_dev(hva);
	unsigned long int version;

	if (pm_runtime_get_sync(dev) < 0) {
		dev_err(dev, "%s     failed to get pm_runtime\n", HVA_PREFIX);
		mutex_unlock(&hva->protect_mutex);
		return -EFAULT;
	}

	version = readl_relaxed(hva->regs + HVA_HIF_REG_VERSION) &
				VERSION_ID_MASK;

	pm_runtime_put_autosuspend(dev);

	switch (version) {
	case HVA_VERSION_V400:
		dev_dbg(dev, "%s     IP hardware version 0x%lx\n",
			HVA_PREFIX, version);
		break;
	default:
		dev_err(dev, "%s     unknown IP hardware version 0x%lx\n",
			HVA_PREFIX, version);
		version = HVA_VERSION_UNKNOWN;
		break;
	}

	return version;
}

int hva_hw_probe(struct platform_device *pdev, struct hva_dev *hva)
{
	struct device *dev = &pdev->dev;
	struct resource *regs;
	struct resource *esram;
	int ret;

	WARN_ON(!hva);

	/* get memory for registers */
	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	hva->regs = devm_ioremap_resource(dev, regs);
	if (IS_ERR(hva->regs)) {
		dev_err(dev, "%s     failed to get regs\n", HVA_PREFIX);
		return PTR_ERR(hva->regs);
	}

	/* get memory for esram */
	esram = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	if (!esram) {
		dev_err(dev, "%s     failed to get esram\n", HVA_PREFIX);
		return -ENODEV;
	}
	hva->esram_addr = esram->start;
	hva->esram_size = resource_size(esram);

	dev_info(dev, "%s     esram reserved for address: 0x%x size:%d\n",
		 HVA_PREFIX, hva->esram_addr, hva->esram_size);

	/* get clock resource */
	hva->clk = devm_clk_get(dev, "clk_hva");
	if (IS_ERR(hva->clk)) {
		dev_err(dev, "%s     failed to get clock\n", HVA_PREFIX);
		return PTR_ERR(hva->clk);
	}

	ret = clk_prepare(hva->clk);
	if (ret < 0) {
		dev_err(dev, "%s     failed to prepare clock\n", HVA_PREFIX);
		hva->clk = ERR_PTR(-EINVAL);
		return ret;
	}

	/* get status interruption resource */
	ret  = platform_get_irq(pdev, 0);
	if (ret < 0) {
		dev_err(dev, "%s     failed to get status IRQ\n", HVA_PREFIX);
		goto err_clk;
	}
	hva->irq_its = ret;

	ret = devm_request_threaded_irq(dev, hva->irq_its, hva_hw_its_interrupt,
					hva_hw_its_irq_thread,
					IRQF_ONESHOT,
					"hva_its_irq", hva);
	if (ret) {
		dev_err(dev, "%s     failed to install status IRQ 0x%x\n",
			HVA_PREFIX, hva->irq_its);
		goto err_clk;
	}
	disable_irq(hva->irq_its);

	/* get error interruption resource */
	ret = platform_get_irq(pdev, 1);
	if (ret < 0) {
		dev_err(dev, "%s     failed to get error IRQ\n", HVA_PREFIX);
		goto err_clk;
	}
	hva->irq_err = ret;

	ret = devm_request_threaded_irq(dev, hva->irq_err, hva_hw_err_interrupt,
					hva_hw_err_irq_thread,
					IRQF_ONESHOT,
					"hva_err_irq", hva);
	if (ret) {
		dev_err(dev, "%s     failed to install error IRQ 0x%x\n",
			HVA_PREFIX, hva->irq_err);
		goto err_clk;
	}
	disable_irq(hva->irq_err);

	/* initialise protection mutex */
	mutex_init(&hva->protect_mutex);

	/* initialise completion signal */
	init_completion(&hva->interrupt);

	/* initialise runtime power management */
	pm_runtime_set_autosuspend_delay(dev, AUTOSUSPEND_DELAY_MS);
	pm_runtime_use_autosuspend(dev);
	pm_runtime_set_suspended(dev);
	pm_runtime_enable(dev);

	ret = pm_runtime_get_sync(dev);
	if (ret < 0) {
		dev_err(dev, "%s     failed to set PM\n", HVA_PREFIX);
		goto err_clk;
	}

	/* check IP hardware version */
	hva->ip_version = hva_hw_get_ip_version(hva);

	if (hva->ip_version == HVA_VERSION_UNKNOWN) {
		ret = -EINVAL;
		goto err_pm;
	}

	dev_info(dev, "%s     found hva device (version 0x%lx)\n", HVA_PREFIX,
		 hva->ip_version);

	return 0;

err_pm:
	pm_runtime_put(dev);
err_clk:
	if (hva->clk)
		clk_unprepare(hva->clk);

	return ret;
}

void hva_hw_remove(struct hva_dev *hva)
{
	struct device *dev = hva_to_dev(hva);

	disable_irq(hva->irq_its);
	disable_irq(hva->irq_err);

	pm_runtime_put_autosuspend(dev);
	pm_runtime_disable(dev);
}

int hva_hw_runtime_suspend(struct device *dev)
{
	struct hva_dev *hva = dev_get_drvdata(dev);

	clk_disable_unprepare(hva->clk);

	return 0;
}

int hva_hw_runtime_resume(struct device *dev)
{
	struct hva_dev *hva = dev_get_drvdata(dev);

	if (clk_prepare_enable(hva->clk)) {
		dev_err(hva->dev, "%s     failed to prepare hva clk\n",
			HVA_PREFIX);
		return -EINVAL;
	}

	if (clk_set_rate(hva->clk, CLK_RATE)) {
		dev_err(dev, "%s     failed to set clock frequency\n",
			HVA_PREFIX);
		return -EINVAL;
	}

	return 0;
}

int hva_hw_execute_task(struct hva_ctx *ctx, enum hva_hw_cmd_type cmd,
			struct hva_buffer *task)
{
	struct hva_dev *hva = ctx_to_hdev(ctx);
	struct device *dev = hva_to_dev(hva);
	u8 client_id = ctx->id;
	int ret;
	u32 reg = 0;

	mutex_lock(&hva->protect_mutex);

	/* enable irqs */
	enable_irq(hva->irq_its);
	enable_irq(hva->irq_err);

	if (pm_runtime_get_sync(dev) < 0) {
		dev_err(dev, "%s     failed to get pm_runtime\n", ctx->name);
		ret = -EFAULT;
		goto out;
	}

	reg = readl_relaxed(hva->regs + HVA_HIF_REG_CLK_GATING);
	switch (cmd) {
	case H264_ENC:
		reg |= CLK_GATING_HVC;
		break;
	default:
		dev_dbg(dev, "%s     unknown command 0x%x\n", ctx->name, cmd);
		ret = -EFAULT;
		goto out;
	}
	writel_relaxed(reg, hva->regs + HVA_HIF_REG_CLK_GATING);

	dev_dbg(dev, "%s     %s: write configuration registers\n", ctx->name,
		__func__);

	/* byte swap config */
	writel_relaxed(BSM_CFG_VAL1, hva->regs + HVA_HIF_REG_BSM);

	/* define Max Opcode Size and Max Message Size for LMI and EMI */
	writel_relaxed(MIF_CFG_VAL3, hva->regs + HVA_HIF_REG_MIF_CFG);
	writel_relaxed(HEC_MIF_CFG_VAL, hva->regs + HVA_HIF_REG_HEC_MIF_CFG);

	/*
	 * command FIFO: task_id[31:16] client_id[15:8] command_type[7:0]
	 * the context identifier is provided as client identifier to the
	 * hardware, and is retrieved in the interrupt functions from the
	 * status register
	 */
	dev_dbg(dev, "%s     %s: send task (cmd: %d, task_desc: %pad)\n",
		ctx->name, __func__, cmd + (client_id << 8), &task->paddr);
	writel_relaxed(cmd + (client_id << 8), hva->regs + HVA_HIF_FIFO_CMD);
	writel_relaxed(task->paddr, hva->regs + HVA_HIF_FIFO_CMD);

	if (!wait_for_completion_timeout(&hva->interrupt,
					 msecs_to_jiffies(2000))) {
		dev_err(dev, "%s     %s: time out on completion\n", ctx->name,
			__func__);
		ret = -EFAULT;
		goto out;
	}

	/* get encoding status */
	ret = ctx->hw_err ? -EFAULT : 0;

out:
	disable_irq(hva->irq_its);
	disable_irq(hva->irq_err);

	switch (cmd) {
	case H264_ENC:
		reg &= ~CLK_GATING_HVC;
		writel_relaxed(reg, hva->regs + HVA_HIF_REG_CLK_GATING);
		break;
	default:
		dev_dbg(dev, "%s     unknown command 0x%x\n", ctx->name, cmd);
	}

	pm_runtime_put_autosuspend(dev);
	mutex_unlock(&hva->protect_mutex);

	return ret;
}