/*
 * Broadcom PCIe 1570 webcam driver
 *
 * Copyright (C) 2014 Patrik Jakobsson (patrik.r.jakobsson@gmail.com)
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 */

#include <linux/delay.h>
#include "bcwc_drv.h"
#include "bcwc_hw.h"

/* Used after most PCI Link IO writes */
static inline void bcwc_hw_pci_post(struct bcwc_private *dev_priv)
{
	pci_write_config_dword(dev_priv->pdev, 0, 0x12345678);
}

static int bcwc_hw_set_core_clk(struct bcwc_private *dev_priv)
{
	return 0;
}

static int bcwc_hw_s2_pll_reset(struct bcwc_private *dev_priv)
{
	BCWC_S2_REG_WRITE(0x40, S2_PLL_CTRL_2C);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x0, S2_PLL_CTRL_2C);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0xbcbc1500, S2_PLL_CTRL_100);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x0, S2_PLL_CTRL_14);
	bcwc_hw_pci_post(dev_priv);

	udelay(10000);

	BCWC_S2_REG_WRITE(0x3, S2_PLL_CTRL_14);
	bcwc_hw_pci_post(dev_priv);

	dev_info(&dev_priv->pdev->dev, "PLL reset finished\n");

	return 0;
}

static int bcwc_hw_s2_init_pcie_link(struct bcwc_private *dev_priv)
{
	u32 reg;

	reg = BCWC_S2_REG_READ(S2_PCIE_LINK_D000);
	BCWC_S2_REG_WRITE(reg | 0x10, S2_PCIE_LINK_D000);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x1804, S2_PCIE_LINK_D120);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0xac5800, S2_PCIE_LINK_D124);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x1804, S2_PCIE_LINK_D120);
	bcwc_hw_pci_post(dev_priv);

	/* Check if PLL is powered down when S2 PCIe link is in L1 state */
	reg = BCWC_S2_REG_READ(S2_PCIE_LINK_D124);
	if (reg != 0xac5800) {
		dev_err(&dev_priv->pdev->dev,
			"Failed to init S2 PCIe link: %u\n", reg);
		return -EIO;
	}

	/* PLL is powered down */
	dev_info(&dev_priv->pdev->dev, "S2 PCIe link init succeeded\n");

	BCWC_S2_REG_WRITE(0x1f08, S2_PCIE_LINK_D128);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x80008610, S2_PCIE_LINK_D12C);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x1608, S2_PCIE_LINK_D128);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x8000fc00, S2_PCIE_LINK_D12C);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x1f08, S2_PCIE_LINK_D128);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x80008610, S2_PCIE_LINK_D12C);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x1708, S2_PCIE_LINK_D128);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x800005bf, S2_PCIE_LINK_D12C);
	bcwc_hw_pci_post(dev_priv);

	return 0;
}

static int bcwc_hw_s2_pll_init(struct bcwc_private *dev_priv, u32 ddr_speed)
{
	u32 ref_clk_25;
	u32 reg;
	int retries = 0;

	ref_clk_25 = BCWC_S2_REG_READ(S2_PLL_STATUS_04) & S2_PLL_REFCLK;

	if (ref_clk_25)
		dev_info(&dev_priv->pdev->dev, "Refclk: 25MHz\n");
	else
		dev_info(&dev_priv->pdev->dev, "Refclk: 24MHz\n");

	if (ddr_speed == 400) {
		if (ref_clk_25) {
			/* Ref clk 25 */
			BCWC_S2_REG_WRITE(0x00400078, S2_PLL_CTRL_510);
			bcwc_hw_pci_post(dev_priv);
			BCWC_S2_REG_WRITE(0x19280804, S2_PLL_CTRL_24);
		} else {
			/* Ref clk 24 */
			BCWC_S2_REG_WRITE(0x03200000, S2_PLL_CTRL_20);
			bcwc_hw_pci_post(dev_priv);
			BCWC_S2_REG_WRITE(0x14280603, S2_PLL_CTRL_24);
		}
	} else if (ddr_speed == 300) {
		if (ref_clk_25) {
			/* Ref clk 25 */
			BCWC_S2_REG_WRITE(0x00480078, S2_PLL_CTRL_510);
			bcwc_hw_pci_post(dev_priv);
			BCWC_S2_REG_WRITE(0x19280c06, S2_PLL_CTRL_24);
		} else {
			/* Ref clk 24 */
			BCWC_S2_REG_WRITE(0x03200000, S2_PLL_CTRL_20);
			bcwc_hw_pci_post(dev_priv);
			BCWC_S2_REG_WRITE(0x14280804, S2_PLL_CTRL_24);
		}
	} else if (ddr_speed == 200) {
		if (ref_clk_25) {
			/* Ref clk 25 */
			BCWC_S2_REG_WRITE(0x00400078, S2_PLL_CTRL_510);
			bcwc_hw_pci_post(dev_priv);
			BCWC_S2_REG_WRITE(0x19281008, S2_PLL_CTRL_24);
		} else {
			/* Ref clk 24 */
			BCWC_S2_REG_WRITE(0x03200000, S2_PLL_CTRL_20);
			bcwc_hw_pci_post(dev_priv);
			BCWC_S2_REG_WRITE(0x14280c06, S2_PLL_CTRL_24);
		}
	} else {
		if (ddr_speed != 450) {
			dev_err(&dev_priv->pdev->dev,
				"Unsupported DDR speed %uMHz, using 450MHz\n",
				ddr_speed);
		}
		ddr_speed = 450;

		if (ref_clk_25) {
			/* Ref clk 25 */
			BCWC_S2_REG_WRITE(0x0048007d, S2_PLL_CTRL_510);
			bcwc_hw_pci_post(dev_priv);
			BCWC_S2_REG_WRITE(0x19280904, S2_PLL_CTRL_24);
		} else {
			/* Ref clk 24 */
			BCWC_S2_REG_WRITE(0x04b00000, S2_PLL_CTRL_20);
			bcwc_hw_pci_post(dev_priv);
			BCWC_S2_REG_WRITE(0x14280904, S2_PLL_CTRL_24);

		}
	}

	bcwc_hw_pci_post(dev_priv);
	bcwc_hw_s2_pll_reset(dev_priv);

	dev_info(&dev_priv->pdev->dev, "Waiting for PLL to lock for %d MHz\n",
		 ddr_speed);

	do {
		reg = BCWC_S2_REG_READ(S2_PLL_STATUS_0C);
		udelay(10);
		retries++;
	} while ((reg & 0x8000) == 0 && retries <= 10000);

	if (retries > 10000) {
		dev_info(&dev_priv->pdev->dev, "Failed to lock PLL: 0x%x\n",
			 reg);
		return -EINVAL;
	} else {
		dev_info(&dev_priv->pdev->dev, "PLL is locked after %d us\n",
			 (retries * 10));
	}

	reg = BCWC_S2_REG_READ(S2_PLL_STATUS_A8);
	BCWC_S2_REG_WRITE(reg | S2_PLL_BYPASS, S2_PLL_STATUS_A8);
	bcwc_hw_pci_post(dev_priv);
	udelay(10000);

	reg = BCWC_S2_REG_READ(S2_PLL_STATUS_A8);
	if (reg & 0x1) {
		dev_info(&dev_priv->pdev->dev, "PLL is in bypass mode\n");
	} else {
		dev_info(&dev_priv->pdev->dev, "PLL is in non-bypass mode\n");
	}

	return 0;
}

static int bcwc_hw_s2_preinit_ddr_controller_soc(struct bcwc_private *dev_priv)
{
	/* Wingardium leviosa */
	BCWC_S2_REG_WRITE(0x203, S2_DDR_REG_1100);
	bcwc_hw_pci_post(dev_priv);
	BCWC_S2_REG_WRITE(0x203, S2_DDR_REG_1104);
	bcwc_hw_pci_post(dev_priv);
	BCWC_S2_REG_WRITE(0x203, S2_DDR_REG_1108);
	bcwc_hw_pci_post(dev_priv);
	BCWC_S2_REG_WRITE(0x203, S2_DDR_REG_110C);
	bcwc_hw_pci_post(dev_priv);
	BCWC_S2_REG_WRITE(0x203, S2_DDR_REG_1110);
	bcwc_hw_pci_post(dev_priv);
	BCWC_S2_REG_WRITE(0x203, S2_DDR_REG_1114);
	bcwc_hw_pci_post(dev_priv);
	BCWC_S2_REG_WRITE(0x203, S2_DDR_REG_1118);
	bcwc_hw_pci_post(dev_priv);
	BCWC_S2_REG_WRITE(0x203, S2_DDR_REG_111C);
	bcwc_hw_pci_post(dev_priv);

	return 0;
}

static int bcwc_hw_ddr_phy_soft_reset(struct bcwc_private *dev_priv)
{
	/* Clear status bits? */
	BCWC_S2_REG_WRITE(0x281, S2_PLL_STATUS_A8);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0xfffff, S2_PLL_CTRL_9C);
	bcwc_hw_pci_post(dev_priv);

	udelay(10000);

	BCWC_S2_REG_WRITE(0xffbff, S2_PLL_CTRL_9C);
	bcwc_hw_pci_post(dev_priv);

	return 0;
}

static int bcwc_hw_s2_init_ddr_controller_soc(struct bcwc_private *dev_priv)
{
	u32 cmd;
	u32 val;
	u32 reg;
	int ret, i;

	/* Set DDR speed (450 MHz for now) */
	dev_priv->ddr_speed = 450;

	/* Read PCI config command register */
	ret = pci_read_config_dword(dev_priv->pdev, 4, &cmd);
	if (ret) {
		dev_err(&dev_priv->pdev->dev, "Failed to read PCI config\n");
		return -EIO;
	}

	if ((cmd & 0x07) == 0) {
		dev_err(&dev_priv->pdev->dev,
			"PCI link in illegal state, cfg_cmd_reg: 0x%x\n", cmd);
		return -EIO;
	}

	reg = BCWC_S2_REG_READ(S2_PLL_CTRL_9C);
	reg &= 0xfffffcff;

	BCWC_S2_REG_WRITE(reg, S2_PLL_CTRL_9C);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(reg | 0x300, S2_PLL_CTRL_9C);
	bcwc_hw_pci_post(dev_priv);

	/* Default to 450 MHz DDR speed for now */
	bcwc_hw_s2_pll_init(dev_priv, 450);

	bcwc_hw_ddr_phy_soft_reset(dev_priv);

	/* Not sure what this is yet (perhaps safe/slow DDR PLL settings) */
	BCWC_S2_REG_WRITE(0x2, S2_2BA4);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x2, S2_2BA8);
	bcwc_hw_pci_post(dev_priv);

	/* Disable the hardware frequency change function */
	BCWC_S2_REG_WRITE(0x3f4, S2_20F8);
	bcwc_hw_pci_post(dev_priv);

	/* Setup the PLL */
	BCWC_S2_REG_WRITE(0x40, S2_2434);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x10000000, S2_2438);
	bcwc_hw_pci_post(dev_priv);

	/* Wait for DDR PLL to lock */
	for (i = 0; i <= 10000; i++) {
		reg = BCWC_S2_REG_READ(S2_DDR_PLL_STATUS_2444);
		if (reg & S2_DDR_PLL_STATUS_2444_LOCKED)
			break;
		udelay(10);
	}

	if (i > 10000) {
		dev_err(&dev_priv->pdev->dev,
			"Failed to lock DDR PHY PLL in stage 1\n");
		return -EIO;
	}

	BCWC_S2_REG_WRITE(0x1f37205, S2_2430);
	bcwc_hw_pci_post(dev_priv);

	for (i = 0; i <= 10000; i++) {
		reg = BCWC_S2_REG_READ(S2_DDR_PLL_STATUS_241C);
		if (reg & S2_DDR_PLL_STATUS_241C_LOCKED)
			break;
		udelay(10);
	}

	if (i > 10000) {
		dev_err(&dev_priv->pdev->dev,
			"Failed to lock DDR PHY PLL in stage 2\n");
		return -EIO;
	}

	udelay(10000);

	BCWC_S2_REG_WRITE(0x0c10, S2_DDR_281C);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x0010, S2_DDR_2814);
	bcwc_hw_pci_post(dev_priv);

	for (i = 0; i <= 10000; i++) {
		reg = BCWC_S2_REG_READ(S2_DDR_PLL_STATUS_2810);
		if (reg & S2_DDR_PLL_STATUS_2810_LOCKED)
			break;
		udelay(10);
	}

	if (i > 10000) {
		dev_err(&dev_priv->pdev->dev,
			"Failed to lock DDR PHY PLL in stage 3\n");
		return -EIO;
	}

	dev_info(&dev_priv->pdev->dev, "DDR PHY PLL locked on safe settings\n");

	/* Default is DDR model 4 */
	if (dev_priv->ddr_model == 2)
		val = 0x42500c2;
	else
		val = 0x46a00c2;

	BCWC_S2_REG_WRITE(0x10737545, S2_DDR_20A0);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x12643173, S2_DDR_20A4);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0xff3f, S2_DDR_20A8);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(val, S2_DDR_20B0);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x101f, S2_DDR_2118);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x1c0, S2_DDR_2820);
	bcwc_hw_pci_post(dev_priv);

	if (dev_priv->ddr_model == 2)
		val = 0x2155558;
	else
		val = 0x2159518;

	BCWC_S2_REG_WRITE(val, S2_DDR_28B0);
	bcwc_hw_pci_post(dev_priv);

	if (dev_priv->ddr_speed == 450)
		val = 0x108307;
	else
		val = 0x108286;

	BCWC_S2_REG_WRITE(val, S2_DDR_28B4);
	bcwc_hw_pci_post(dev_priv);

	BCWC_S2_REG_WRITE(0x2159559, S2_DDR_28B0);
	bcwc_hw_pci_post(dev_priv);

	/* Polling for STRAP valid */
	for (i = 0; i < 10000; i++) {
		reg = BCWC_S2_REG_READ(S2_DDR_STATUS_28B8);
		if (reg & 0x1)
			break;
		udelay(10);
	}

	if (i >= 10000) {
		dev_err(&dev_priv->pdev->dev,
			"Timeout waiting for STRAP valid\n");
		return -ENODEV;
	} else {
		dev_info(&dev_priv->pdev->dev, "STRAP valid\n");
	}

	/* Manual DDR40 PHY init */
	if (dev_priv->ddr_speed != 450) {
		dev_warn(&dev_priv->pdev->dev,
			 "DDR frequency is %u (should be 450 MHz)",
			 dev_priv->ddr_speed);
	}

	dev_info(&dev_priv->pdev->dev,
		 "Configuring DDR PLLs for %u MHz\n", dev_priv->ddr_speed);

	if ((dev_priv->ddr_speed * 2) < 500)
		val = 0x2040;
	else
		val = 0x810;

	/* Start programming the DDR PLL */
	reg = BCWC_S2_REG_READ(S2_DDR_281C);
	reg &= 0xffffc700;
	val |= reg;

	BCWC_S2_REG_WRITE(val, S2_DDR_281C);
	bcwc_hw_pci_post(dev_priv);

	reg = BCWC_S2_REG_READ(S2_DDR_2814);
	reg &= 0xfffffffd;
	BCWC_S2_REG_WRITE(reg, S2_DDR_2814);
	bcwc_hw_pci_post(dev_priv);

	/* Start polling for the lock */
	for (i = 0; i < 100; i++) {
		reg = BCWC_S2_REG_READ(S2_DDR_PLL_STATUS_2810);
		if (reg & S2_DDR_PLL_STATUS_2810_LOCKED)
			break;
		udelay(1);
	}

	if (i >= 100) {
		dev_err(&dev_priv->pdev->dev, "Failed to lock the DDR PLL\n");
		return -ENODEV;
	}

	dev_info(&dev_priv->pdev->dev, "DDR PLL is locked\n");

	/* FIXME: Unfinished */

	return 0;
}

static int bcwc_hw_save_ddr_phy_regs(struct bcwc_private *dev_priv)
{
	u32 reg, offset;
	int i;

	if (dev_priv->ddr_phy_num_regs == 0)
		return -ENOENT;

	for (i = 0; i < dev_priv->ddr_phy_num_regs; i++) {
		offset = dev_priv->ddr_reg_map[i].offset;
		reg = BCWC_ISP_REG_READ(offset + DDR_PHY_REG_BASE);
		dev_priv->ddr_reg_map[i].value = reg;
	}

	return 0;
}

static int bcwc_hw_isp_init(struct bcwc_private *dev_priv)
{
	u32 num_channels, queue_size;
	u32 reg;
	int i, retries;

	BCWC_ISP_REG_WRITE(0, IRQ_IPC_NUM_CHAN);
	bcwc_hw_pci_post(dev_priv);

	BCWC_ISP_REG_WRITE(0, IRQ_IPC_QUEUE_SIZE);
	bcwc_hw_pci_post(dev_priv);

	BCWC_ISP_REG_WRITE(0, IRQ_REG_08);
	bcwc_hw_pci_post(dev_priv);

	BCWC_ISP_REG_WRITE(0, IRQ_FW_HEAP_SIZE);
	bcwc_hw_pci_post(dev_priv);

	BCWC_ISP_REG_WRITE(0, IRQ_REG_10);
	bcwc_hw_pci_post(dev_priv);

	BCWC_ISP_REG_WRITE(0, IRQ_REG_14);
	bcwc_hw_pci_post(dev_priv);

	BCWC_ISP_REG_WRITE(0, IRQ_REG_18);
	bcwc_hw_pci_post(dev_priv);

	BCWC_ISP_REG_WRITE(0, IRQ_REG_1C);
	bcwc_hw_pci_post(dev_priv);

	BCWC_ISP_REG_WRITE(0xffffffff, IRQ_REG_41024);
	bcwc_hw_pci_post(dev_priv);

	/*
	 * Probably the IPC queue
	 * FIXME: Check if we can do 64bit writes on PCIe
	 */
	for (i = IRQ_REG_RANGE_START; i <= IRQ_REG_RANGE_END; i += 8) {
		BCWC_ISP_REG_WRITE(0xffffff, i);
		BCWC_ISP_REG_WRITE(0x000000, i + 4);
	}
	bcwc_hw_pci_post(dev_priv);

	BCWC_ISP_REG_WRITE( 0x80000000, IRQ_REG_40008);
	bcwc_hw_pci_post(dev_priv);

	BCWC_ISP_REG_WRITE(0x1, IRQ_REG_40004);
	bcwc_hw_pci_post(dev_priv);


	for (retries = 0; retries < 1000; retries++) {
		reg = BCWC_ISP_REG_READ(IRQ_REG_40004);
		if ((reg & 0xff) == 0xf0)
			break;
		udelay(10);
	}

	if (retries >= 1000) {
		dev_info(&dev_priv->pdev->dev, "Init failed! No wake signal\n");
		return -EIO;
	}

	BCWC_ISP_REG_WRITE(0xffffffff, IRQ_REG_41024);

	num_channels = BCWC_ISP_REG_READ(IRQ_IPC_NUM_CHAN) + 1;
	queue_size = BCWC_ISP_REG_READ(IRQ_IPC_QUEUE_SIZE);

	dev_info(&dev_priv->pdev->dev,
		 "Number of IPC channels: %u, queue size: %u\n",
		 num_channels, queue_size);

	if (num_channels > 32) {
		dev_info(&dev_priv->pdev->dev, "Too many IPC channels: %u\n",
			 num_channels);
		return -EIO;
	}

	/*
	bcwc_alloc_dev_mem(queue_size, &ret, 0);
	*/

	/* Firmware must fit in 4194304 bytes */
	reg = BCWC_ISP_REG_READ(IRQ_FW_HEAP_SIZE);
	if (reg > 0x400000) {
		dev_info(&dev_priv->pdev->dev,
			 "Firmware request size too big (%u bytes)\n",
			 reg);
		return -ENOMEM;
	}

	dev_info(&dev_priv->pdev->dev, "Firmware request size: %u\n", reg);

	return 0;
}

static int bcwc_hw_irq_enable(struct bcwc_private *dev_priv)
{
	return 0;
}

static int bcwc_hw_irq_disable(struct bcwc_private *dev_priv)
{
	return 0;
}

static int bcwc_hw_sensor_enable(struct bcwc_private *dev_priv)
{
	return 0;
}

static int bcwc_hw_sensor_disable(struct bcwc_private *dev_priv)
{
	return 0;
}

static int bcwc_hw_s2chip_enable(struct bcwc_private *dev_priv)
{
	return 0;
}

static int bcwc_hw_s2chip_disable(struct bcwc_private *dev_priv)
{
	return 0;
}

/* What I've figured out about the power on sequence so far */
static int bcwc_hw_power_on(struct bcwc_private *dev_priv)
{
	bcwc_hw_s2chip_enable(dev_priv);
	bcwc_hw_sensor_enable(dev_priv);
	bcwc_hw_irq_enable(dev_priv);

	return 0;
}

/* What I've figured out about the power off sequence so far */
static int bcwc_hw_power_off(struct bcwc_private *dev_priv)
{
	bcwc_hw_irq_disable(dev_priv);
	bcwc_hw_sensor_disable(dev_priv);
	bcwc_hw_s2chip_disable(dev_priv);

	return 0;
}

int bcwc_hw_init(struct bcwc_private *dev_priv)
{
	int ret;

	ret = bcwc_hw_s2_init_pcie_link(dev_priv);
	if (ret)
		goto out;

	/* Set DDR speed to 450 MHz */
	bcwc_hw_s2_preinit_ddr_controller_soc(dev_priv);
	bcwc_hw_s2_init_ddr_controller_soc(dev_priv);
	// bcwc_hw_isp_init(dev_priv);

out:
	return ret;
}