/*
 * Copyright (C) 2017 Intel Corporation <www.intel.com>
 *
 * SPDX-License-Identifier:    GPL-2.0
 */

#include <asm/io.h>
#include <asm/arch/fpga_manager.h>
#include <asm/arch/reset_manager.h>
#include <asm/arch/system_manager.h>
#include <asm/arch/sdram.h>
#include <asm/arch/misc.h>
#include <altera.h>
#include <common.h>
#include <errno.h>
#include <wait_bit.h>
#include <watchdog.h>

#define CFGWDTH_32	1
#define MIN_BITSTREAM_SIZECHECK	230
#define ENCRYPTION_OFFSET	69
#define COMPRESSION_OFFSET	229
#define FPGA_TIMEOUT_MSEC	1000  /* timeout in ms */
#define FPGA_TIMEOUT_CNT	0x1000000

static const struct socfpga_fpga_manager *fpga_manager_base =
		(void *)SOCFPGA_FPGAMGRREGS_ADDRESS;

static const struct socfpga_system_manager *system_manager_base =
		(void *)SOCFPGA_SYSMGR_ADDRESS;

static void fpgamgr_set_cd_ratio(unsigned long ratio);

static uint32_t fpgamgr_get_msel(void)
{
	u32 reg;

	reg = readl(&fpga_manager_base->imgcfg_stat);
	reg = (reg & ALT_FPGAMGR_IMGCFG_STAT_F2S_MSEL_SET_MSD) >>
		ALT_FPGAMGR_IMGCFG_STAT_F2S_MSEL0_LSB;

	return reg;
}

static void fpgamgr_set_cfgwdth(int width)
{
	if (width)
		setbits_le32(&fpga_manager_base->imgcfg_ctrl_02,
			ALT_FPGAMGR_IMGCFG_CTL_02_CFGWIDTH_SET_MSK);
	else
		clrbits_le32(&fpga_manager_base->imgcfg_ctrl_02,
			ALT_FPGAMGR_IMGCFG_CTL_02_CFGWIDTH_SET_MSK);
}

int is_fpgamgr_user_mode(void)
{
	return (readl(&fpga_manager_base->imgcfg_stat) &
		ALT_FPGAMGR_IMGCFG_STAT_F2S_USERMODE_SET_MSK) != 0;
}

static int wait_for_user_mode(void)
{
	return wait_for_bit_le32(&fpga_manager_base->imgcfg_stat,
		ALT_FPGAMGR_IMGCFG_STAT_F2S_USERMODE_SET_MSK,
		1, FPGA_TIMEOUT_MSEC, false);
}

static int is_fpgamgr_early_user_mode(void)
{
	return (readl(&fpga_manager_base->imgcfg_stat) &
		ALT_FPGAMGR_IMGCFG_STAT_F2S_EARLY_USERMODE_SET_MSK) != 0;
}

int fpgamgr_wait_early_user_mode(void)
{
	u32 sync_data = 0xffffffff;
	u32 i = 0;
	unsigned start = get_timer(0);
	unsigned long cd_ratio;

	/* Getting existing CDRATIO */
	cd_ratio = (readl(&fpga_manager_base->imgcfg_ctrl_02) &
		ALT_FPGAMGR_IMGCFG_CTL_02_CDRATIO_SET_MSK) >>
		ALT_FPGAMGR_IMGCFG_CTL_02_CDRATIO_LSB;

	/* Using CDRATIO_X1 for better compatibility */
	fpgamgr_set_cd_ratio(CDRATIO_x1);

	while (!is_fpgamgr_early_user_mode()) {
		if (get_timer(start) > FPGA_TIMEOUT_MSEC)
			return -ETIMEDOUT;
		fpgamgr_program_write((const long unsigned int *)&sync_data,
				sizeof(sync_data));
		udelay(FPGA_TIMEOUT_MSEC);
		i++;
	}

	debug("Additional %i sync word needed\n", i);

	/* restoring original CDRATIO */
	fpgamgr_set_cd_ratio(cd_ratio);

	return 0;
}

/* Read f2s_nconfig_pin and f2s_nstatus_pin; loop until de-asserted */
static int wait_for_nconfig_pin_and_nstatus_pin(void)
{
	unsigned long mask = ALT_FPGAMGR_IMGCFG_STAT_F2S_NCONFIG_PIN_SET_MSK |
				ALT_FPGAMGR_IMGCFG_STAT_F2S_NSTATUS_PIN_SET_MSK;

	/*
	 * Poll until f2s_nconfig_pin and f2s_nstatus_pin; loop until
	 * de-asserted, timeout at 1000ms
	 */
	return wait_for_bit_le32(&fpga_manager_base->imgcfg_stat, mask,
				 true, FPGA_TIMEOUT_MSEC, false);
}

static int wait_for_f2s_nstatus_pin(unsigned long value)
{
	/* Poll until f2s to specific value, timeout at 1000ms */
	return wait_for_bit_le32(&fpga_manager_base->imgcfg_stat,
		ALT_FPGAMGR_IMGCFG_STAT_F2S_NSTATUS_PIN_SET_MSK,
		value, FPGA_TIMEOUT_MSEC, false);
}

/* set CD ratio */
static void fpgamgr_set_cd_ratio(unsigned long ratio)
{
	clrbits_le32(&fpga_manager_base->imgcfg_ctrl_02,
		ALT_FPGAMGR_IMGCFG_CTL_02_CDRATIO_SET_MSK);

	setbits_le32(&fpga_manager_base->imgcfg_ctrl_02,
		(ratio << ALT_FPGAMGR_IMGCFG_CTL_02_CDRATIO_LSB) &
		ALT_FPGAMGR_IMGCFG_CTL_02_CDRATIO_SET_MSK);
}

/* get the MSEL value, verify we are set for FPP configuration mode */
static int fpgamgr_verify_msel(void)
{
	u32 msel = fpgamgr_get_msel();

	if (msel & ~BIT(0)) {
		printf("Fail: read msel=%d\n", msel);
		return -EPERM;
	}

	return 0;
}

/*
 * Write cdratio and cdwidth based on whether the bitstream is compressed
 * and/or encoded
 */
static int fpgamgr_set_cdratio_cdwidth(unsigned int cfg_width, u32 *rbf_data,
				       size_t rbf_size)
{
	unsigned int cd_ratio;
	bool encrypt, compress;

	/*
         * According to the bitstream specification,
	 * both encryption and compression status are
         * in location before offset 230 of the buffer.
         */
	if (rbf_size < MIN_BITSTREAM_SIZECHECK)
		return -EINVAL;

	encrypt = (rbf_data[ENCRYPTION_OFFSET] >> 2) & 3;
	encrypt = encrypt != 0;

	compress = (rbf_data[COMPRESSION_OFFSET] >> 1) & 1;
	compress = !compress;

	debug("header word %d = %08x\n", 69, rbf_data[69]);
	debug("header word %d = %08x\n", 229, rbf_data[229]);
	debug("read from rbf header: encrypt=%d compress=%d\n", encrypt, compress);

	/*
	 * from the register map description of cdratio in imgcfg_ctrl_02:
	 *  Normal Configuration    : 32bit Passive Parallel
	 *  Partial Reconfiguration : 16bit Passive Parallel
	 */

	/*
	 * cd ratio is dependent on cfg width and whether the bitstream
	 * is encrypted and/or compressed.
	 *
	 * | width | encr. | compr. | cd ratio |
	 * |  16   |   0   |   0    |     1    |
	 * |  16   |   0   |   1    |     4    |
	 * |  16   |   1   |   0    |     2    |
	 * |  16   |   1   |   1    |     4    |
	 * |  32   |   0   |   0    |     1    |
	 * |  32   |   0   |   1    |     8    |
	 * |  32   |   1   |   0    |     4    |
	 * |  32   |   1   |   1    |     8    |
	 */
	if (!compress && !encrypt) {
		cd_ratio = CDRATIO_x1;
	} else {
		if (compress)
			cd_ratio = CDRATIO_x4;
		else
			cd_ratio = CDRATIO_x2;

		/* if 32 bit, double the cd ratio (so register
		   field setting is incremented) */
		if (cfg_width == CFGWDTH_32)
			cd_ratio += 1;
	}

	fpgamgr_set_cfgwdth(cfg_width);
	fpgamgr_set_cd_ratio(cd_ratio);

	return 0;
}

static int fpgamgr_reset(void)
{
	unsigned long reg;

	/* S2F_NCONFIG = 0 */
	clrbits_le32(&fpga_manager_base->imgcfg_ctrl_00,
		ALT_FPGAMGR_IMGCFG_CTL_00_S2F_NCONFIG_SET_MSK);

	/* Wait for f2s_nstatus == 0 */
	if (wait_for_f2s_nstatus_pin(0))
		return -ETIME;

	/* S2F_NCONFIG = 1 */
	setbits_le32(&fpga_manager_base->imgcfg_ctrl_00,
		ALT_FPGAMGR_IMGCFG_CTL_00_S2F_NCONFIG_SET_MSK);

	/* Wait for f2s_nstatus == 1 */
	if (wait_for_f2s_nstatus_pin(1))
		return -ETIME;

	/* read and confirm f2s_condone_pin = 0 and f2s_condone_oe = 1 */
	reg = readl(&fpga_manager_base->imgcfg_stat);
	if ((reg & ALT_FPGAMGR_IMGCFG_STAT_F2S_CONDONE_PIN_SET_MSK) != 0)
		return -EPERM;

	if ((reg & ALT_FPGAMGR_IMGCFG_STAT_F2S_CONDONE_OE_SET_MSK) == 0)
		return -EPERM;

	return 0;
}

/* Start the FPGA programming by initialize the FPGA Manager */
int fpgamgr_program_init(u32 * rbf_data, size_t rbf_size)
{
	int ret;

	/* Step 1 */
	if (fpgamgr_verify_msel())
		return -EPERM;

	/* Step 2 */
	if (fpgamgr_set_cdratio_cdwidth(CFGWDTH_32, rbf_data, rbf_size))
		return -EPERM;

	/*
	 * Step 3:
	 * Make sure no other external devices are trying to interfere with
	 * programming:
	 */
	if (wait_for_nconfig_pin_and_nstatus_pin())
		return -ETIME;

	/*
	 * Step 4:
	 * Deassert the signal drives from HPS
	 *
	 * S2F_NCE = 1
	 * S2F_PR_REQUEST = 0
	 * EN_CFG_CTRL = 0
	 * EN_CFG_DATA = 0
	 * S2F_NCONFIG = 1
	 * S2F_NSTATUS_OE = 0
	 * S2F_CONDONE_OE = 0
	 */
	setbits_le32(&fpga_manager_base->imgcfg_ctrl_01,
		ALT_FPGAMGR_IMGCFG_CTL_01_S2F_NCE_SET_MSK);

	clrbits_le32(&fpga_manager_base->imgcfg_ctrl_01,
		ALT_FPGAMGR_IMGCFG_CTL_01_S2F_PR_REQUEST_SET_MSK);

	clrbits_le32(&fpga_manager_base->imgcfg_ctrl_02,
		ALT_FPGAMGR_IMGCFG_CTL_02_EN_CFG_DATA_SET_MSK |
		ALT_FPGAMGR_IMGCFG_CTL_02_EN_CFG_CTRL_SET_MSK);

	setbits_le32(&fpga_manager_base->imgcfg_ctrl_00,
		ALT_FPGAMGR_IMGCFG_CTL_00_S2F_NCONFIG_SET_MSK);

	clrbits_le32(&fpga_manager_base->imgcfg_ctrl_00,
		ALT_FPGAMGR_IMGCFG_CTL_00_S2F_NSTATUS_OE_SET_MSK |
		ALT_FPGAMGR_IMGCFG_CTL_00_S2F_CONDONE_OE_SET_MSK);

	/*
	 * Step 5:
	 * Enable overrides
	 * S2F_NENABLE_CONFIG = 0
	 * S2F_NENABLE_NCONFIG = 0
	 */
	clrbits_le32(&fpga_manager_base->imgcfg_ctrl_01,
		ALT_FPGAMGR_IMGCFG_CTL_01_S2F_NENABLE_CONFIG_SET_MSK);
	clrbits_le32(&fpga_manager_base->imgcfg_ctrl_00,
		ALT_FPGAMGR_IMGCFG_CTL_00_S2F_NENABLE_NCONFIG_SET_MSK);

	/*
	 * Disable driving signals that HPS doesn't need to drive.
	 * S2F_NENABLE_NSTATUS = 1
	 * S2F_NENABLE_CONDONE = 1
	 */
	setbits_le32(&fpga_manager_base->imgcfg_ctrl_00,
		ALT_FPGAMGR_IMGCFG_CTL_00_S2F_NENABLE_NSTATUS_SET_MSK |
		ALT_FPGAMGR_IMGCFG_CTL_00_S2F_NENABLE_CONDONE_SET_MSK);

	/*
	 * Step 6:
	 * Drive chip select S2F_NCE = 0
	 */
	 clrbits_le32(&fpga_manager_base->imgcfg_ctrl_01,
		ALT_FPGAMGR_IMGCFG_CTL_01_S2F_NCE_SET_MSK);

	/* Step 7 */
	if (wait_for_nconfig_pin_and_nstatus_pin())
		return -ETIME;

	/* Step 8 */
	ret = fpgamgr_reset();

	if (ret)
		return ret;

	/*
	 * Step 9:
	 * EN_CFG_CTRL and EN_CFG_DATA = 1
	 */
	setbits_le32(&fpga_manager_base->imgcfg_ctrl_02,
		ALT_FPGAMGR_IMGCFG_CTL_02_EN_CFG_DATA_SET_MSK |
		ALT_FPGAMGR_IMGCFG_CTL_02_EN_CFG_CTRL_SET_MSK);

	return 0;
}

/* Ensure the FPGA entering config done */
static int fpgamgr_program_poll_cd(void)
{
	unsigned long reg, i;

	for (i = 0; i < FPGA_TIMEOUT_CNT; i++) {
		reg = readl(&fpga_manager_base->imgcfg_stat);
		if (reg & ALT_FPGAMGR_IMGCFG_STAT_F2S_CONDONE_PIN_SET_MSK)
			return 0;

		if ((reg & ALT_FPGAMGR_IMGCFG_STAT_F2S_NSTATUS_PIN_SET_MSK) == 0) {
			printf("nstatus == 0 while waiting for condone\n");
			return -EPERM;
		}
	}

	if (i == FPGA_TIMEOUT_CNT)
		return -ETIME;

	return 0;
}

/* Ensure the FPGA entering user mode */
static int fpgamgr_program_poll_usermode(void)
{
	unsigned long reg;
	int ret = 0;

	if (fpgamgr_dclkcnt_set(0xf))
		return -ETIME;

	ret = wait_for_user_mode();
	if (ret < 0) {
		printf("%s: Failed to enter user mode with ", __func__);
		printf("error code %d\n", ret);
		return ret;
	}

	/*
	 * Step 14:
	 * Stop DATA path and Dclk
	 * EN_CFG_CTRL and EN_CFG_DATA = 0
	 */
	clrbits_le32(&fpga_manager_base->imgcfg_ctrl_02,
		ALT_FPGAMGR_IMGCFG_CTL_02_EN_CFG_DATA_SET_MSK |
		ALT_FPGAMGR_IMGCFG_CTL_02_EN_CFG_CTRL_SET_MSK);

	/*
	 * Step 15:
	 * Disable overrides
	 * S2F_NENABLE_CONFIG = 1
	 * S2F_NENABLE_NCONFIG = 1
	 */
	setbits_le32(&fpga_manager_base->imgcfg_ctrl_01,
		ALT_FPGAMGR_IMGCFG_CTL_01_S2F_NENABLE_CONFIG_SET_MSK);
	setbits_le32(&fpga_manager_base->imgcfg_ctrl_00,
		ALT_FPGAMGR_IMGCFG_CTL_00_S2F_NENABLE_NCONFIG_SET_MSK);

	/* Disable chip select S2F_NCE = 1 */
	setbits_le32(&fpga_manager_base->imgcfg_ctrl_01,
		ALT_FPGAMGR_IMGCFG_CTL_01_S2F_NCE_SET_MSK);

	/*
	 * Step 16:
	 * Final check
	 */
	reg = readl(&fpga_manager_base->imgcfg_stat);
	if (((reg & ALT_FPGAMGR_IMGCFG_STAT_F2S_USERMODE_SET_MSK) !=
		ALT_FPGAMGR_IMGCFG_STAT_F2S_USERMODE_SET_MSK) ||
	    ((reg & ALT_FPGAMGR_IMGCFG_STAT_F2S_CONDONE_PIN_SET_MSK) !=
		ALT_FPGAMGR_IMGCFG_STAT_F2S_CONDONE_PIN_SET_MSK) ||
	    ((reg & ALT_FPGAMGR_IMGCFG_STAT_F2S_NSTATUS_PIN_SET_MSK) !=
		ALT_FPGAMGR_IMGCFG_STAT_F2S_NSTATUS_PIN_SET_MSK))
		return -EPERM;

	return 0;
}

int fpgamgr_program_finish(void)
{
	/* Ensure the FPGA entering config done */
	int status = fpgamgr_program_poll_cd();

	if (status) {
		printf("FPGA: Poll CD failed with error code %d\n", status);
		return -EPERM;
	}
	WATCHDOG_RESET();

	/* Ensure the FPGA entering user mode */
	status = fpgamgr_program_poll_usermode();
	if (status) {
		printf("FPGA: Poll usermode failed with error code %d\n",
			status);
		return -EPERM;
	}

	printf("Full Configuration Succeeded.\n");

	return 0;
}

/*
 * FPGA Manager to program the FPGA. This is the interface used by FPGA driver.
 * Return 0 for sucess, non-zero for error.
 */
int socfpga_load(Altera_desc *desc, const void *rbf_data, size_t rbf_size)
{
	unsigned long status;

	/* disable all signals from hps peripheral controller to fpga */
	writel(0, &system_manager_base->fpgaintf_en_global);

	/* disable all axi bridge (hps2fpga, lwhps2fpga & fpga2hps) */
	socfpga_bridges_reset();

	/* Initialize the FPGA Manager */
	status = fpgamgr_program_init((u32 *)rbf_data, rbf_size);
	if (status)
		return status;

	/* Write the RBF data to FPGA Manager */
	fpgamgr_program_write(rbf_data, rbf_size);

	return fpgamgr_program_finish();
}