/*
 *  Copyright (C) 2013 Altera Corporation <www.altera.com>
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <errno.h>
#include <asm/io.h>
#include <asm/arch/freeze_controller.h>
#include <asm/arch/scan_manager.h>
#include <asm/arch/system_manager.h>

/*
 * Maximum polling loop to wait for IO scan chain engine becomes idle
 * to prevent infinite loop. It is important that this is NOT changed
 * to delay using timer functions, since at the time this function is
 * called, timer might not yet be inited.
 */
#define SCANMGR_MAX_DELAY               100

/*
 * Maximum length of TDI_TDO packet payload is 128 bits,
 * represented by (length - 1) in TDI_TDO header.
 */
#define TDI_TDO_MAX_PAYLOAD             127

#define SCANMGR_STAT_ACTIVE             (1 << 31)
#define SCANMGR_STAT_WFIFOCNT_MASK      0x70000000

DECLARE_GLOBAL_DATA_PTR;

static const struct socfpga_scan_manager *scan_manager_base =
                (void *)(SOCFPGA_SCANMGR_ADDRESS);
static const struct socfpga_freeze_controller *freeze_controller_base =
                (void *)(SOCFPGA_SYSMGR_ADDRESS + SYSMGR_FRZCTRL_ADDRESS);
static struct socfpga_system_manager *sys_mgr_base =
        (struct socfpga_system_manager *)SOCFPGA_SYSMGR_ADDRESS;

/**
 * scan_chain_engine_is_idle() - Check if the JTAG scan chain is idle
 * @max_iter:   Maximum number of iterations to wait for idle
 *
 * Function to check IO scan chain engine status and wait if the engine is
 * is active. Poll the IO scan chain engine till maximum iteration reached.
 */
static u32 scan_chain_engine_is_idle(u32 max_iter)
{
        const u32 mask = SCANMGR_STAT_ACTIVE | SCANMGR_STAT_WFIFOCNT_MASK;
        u32 status;

        /* Poll the engine until the scan engine is inactive. */
        do {
                status = readl(&scan_manager_base->stat);
                if (!(status & mask))
                        return 0;
        } while (max_iter--);

        return -ETIMEDOUT;
}

#define JTAG_BP_INSN            (1 << 0)
#define JTAG_BP_TMS             (1 << 1)
#define JTAG_BP_PAYLOAD         (1 << 2)
#define JTAG_BP_2BYTE           (1 << 3)
#define JTAG_BP_4BYTE           (1 << 4)

/**
 * scan_mgr_jtag_io() - Access the JTAG chain
 * @flags:      Control flags, used to configure the action on the JTAG
 * @iarg:       Instruction argument
 * @parg:       Payload argument or data
 *
 * Perform I/O on the JTAG chain
 */
static void scan_mgr_jtag_io(const u32 flags, const u8 iarg, const u32 parg)
{
        u32 data = parg;

        if (flags & JTAG_BP_INSN) {     /* JTAG instruction */
                /*
                 * The SCC JTAG register is LSB first, so make
                 * space for the instruction at the LSB.
                 */
                data <<= 8;
                if (flags & JTAG_BP_TMS) {
                        data |= (0 << 7);       /* TMS instruction. */
                        data |= iarg & 0x3f;    /* TMS arg is 6 bits. */
                        if (flags & JTAG_BP_PAYLOAD)
                                data |= (1 << 6);
                } else {
                        data |= (1 << 7);       /* TDI/TDO instruction. */
                        data |= iarg & 0xf;     /* TDI/TDO arg is 4 bits. */
                        if (flags & JTAG_BP_PAYLOAD)
                                data |= (1 << 4);
                }
        }

        if (flags & JTAG_BP_4BYTE)
                writel(data, &scan_manager_base->fifo_quad_byte);
        else if (flags & JTAG_BP_2BYTE)
                writel(data & 0xffff, &scan_manager_base->fifo_double_byte);
        else
                writel(data & 0xff, &scan_manager_base->fifo_single_byte);
}

/**
 * scan_mgr_jtag_insn_data() - Send JTAG instruction and data
 * @iarg:       Instruction argument
 * @data:       Associated data
 * @dlen:       Length of data in bits
 *
 * This function is used when programming the IO chains to submit the
 * instruction followed by variable length payload.
 */
static int
scan_mgr_jtag_insn_data(const u8 iarg, const unsigned long *data,
                        const unsigned int dlen)
{
        int i, j;

        scan_mgr_jtag_io(JTAG_BP_INSN | JTAG_BP_2BYTE, iarg, dlen - 1);

        /* 32 bits or more remain */
        for (i = 0; i < dlen / 32; i++)
                scan_mgr_jtag_io(JTAG_BP_4BYTE, 0x0, data[i]);

        if ((dlen % 32) > 24) { /* 31...24 bits remain */
                scan_mgr_jtag_io(JTAG_BP_4BYTE, 0x0, data[i]);
        } else if (dlen % 32) { /* 24...1 bit remain */
                for (j = 0; j < dlen % 32; j += 8)
                        scan_mgr_jtag_io(0, 0x0, data[i] >> j);
        }

        return scan_chain_engine_is_idle(SCANMGR_MAX_DELAY);
}

/**
 * scan_mgr_io_scan_chain_prg() - Program HPS IO Scan Chain
 * @io_scan_chain_id:           IO scan chain ID
 */
static int scan_mgr_io_scan_chain_prg(const unsigned int io_scan_chain_id)
{
        u32 io_scan_chain_len_in_bits;
        const unsigned long *iocsr_scan_chain;
        unsigned int rem, idx = 0;
        int ret;

        ret = iocsr_get_config_table(io_scan_chain_id, &iocsr_scan_chain,
                                     &io_scan_chain_len_in_bits);
        if (ret)
                return 1;

        /*
         * De-assert reinit if the IO scan chain is intended for HIO. In
         * this, its the chain 3.
         */
        if (io_scan_chain_id == 3)
                clrbits_le32(&freeze_controller_base->hioctrl,
                             SYSMGR_FRZCTRL_HIOCTRL_DLLRST_MASK);

        /*
         * Check if the scan chain engine is inactive and the
         * WFIFO is empty before enabling the IO scan chain
         */
        ret = scan_chain_engine_is_idle(SCANMGR_MAX_DELAY);
        if (ret)
                return ret;

        /*
         * Enable IO Scan chain based on scan chain id
         * Note: only one chain can be enabled at a time
         */
        setbits_le32(&scan_manager_base->en, 1 << io_scan_chain_id);

        /* Program IO scan chain. */
        while (io_scan_chain_len_in_bits) {
                if (io_scan_chain_len_in_bits > 128)
                        rem = 128;
                else
                        rem = io_scan_chain_len_in_bits;

                ret = scan_mgr_jtag_insn_data(0x0, &iocsr_scan_chain[idx], rem);
                if (ret)
                        goto error;
                io_scan_chain_len_in_bits -= rem;
                idx += 4;
        }

        /* Disable IO Scan chain when configuration done*/
        clrbits_le32(&scan_manager_base->en, 1 << io_scan_chain_id);
        return 0;

error:
        /* Disable IO Scan chain when error detected */
        clrbits_le32(&scan_manager_base->en, 1 << io_scan_chain_id);
        return ret;
}

int scan_mgr_configure_iocsr(void)
{
        int status = 0;

        /* configure the IOCSR through scan chain */
        status |= scan_mgr_io_scan_chain_prg(0);
        status |= scan_mgr_io_scan_chain_prg(1);
        status |= scan_mgr_io_scan_chain_prg(2);
        status |= scan_mgr_io_scan_chain_prg(3);
        return status;
}

/**
 * scan_mgr_get_fpga_id() - Obtain FPGA JTAG ID
 *
 * This function obtains JTAG ID from the FPGA TAP controller.
 */
u32 scan_mgr_get_fpga_id(void)
{
        const unsigned long data = 0;
        u32 id = 0xffffffff;
        int ret;

        /* Enable HPS to talk to JTAG in the FPGA through the System Manager */
        writel(0x1, &sys_mgr_base->scanmgrgrp_ctrl);

        /* Enable port 7 */
        writel(0x80, &scan_manager_base->en);
        /* write to CSW to make s2f_ntrst reset */
        writel(0x02, &scan_manager_base->stat);

        /* Add a pause */
        mdelay(1);

        /* write 0x00 to CSW to clear the s2f_ntrst */
        writel(0, &scan_manager_base->stat);

        /*
         * Go to Test-Logic-Reset state.
         * This sets TAP controller into IDCODE mode.
         */
        scan_mgr_jtag_io(JTAG_BP_INSN | JTAG_BP_TMS, 0x1f | (1 << 5), 0x0);

        /* Go to Run-Test/Idle -> DR-Scan -> Capture-DR -> Shift-DR state. */
        scan_mgr_jtag_io(JTAG_BP_INSN | JTAG_BP_TMS, 0x02 | (1 << 4), 0x0);

        /*
         * Push 4 bytes of data through TDI->DR->TDO.
         *
         * Length of TDI data is 32bits (length - 1) and they are only
         * zeroes as we care only for TDO data.
         */
        ret = scan_mgr_jtag_insn_data(0x4, &data, 32);
        /* Read 32 bit from captured JTAG data. */
        if (!ret)
                id = readl(&scan_manager_base->fifo_quad_byte);

        /* Disable all port */
        writel(0, &scan_manager_base->en);
        writel(0, &sys_mgr_base->scanmgrgrp_ctrl);

        return id;
}