/*
 * Bedbug Functions specific to the PPC405 chip
 */

#include <common.h>
#include <command.h>
#include <linux/ctype.h>
#include <bedbug/type.h>
#include <bedbug/bedbug.h>
#include <bedbug/regs.h>
#include <bedbug/ppc.h>

#if defined(CONFIG_CMD_BEDBUG) && defined(CONFIG_4xx)

#define MAX_BREAK_POINTS 4

extern CPU_DEBUG_CTX bug_ctx;

void bedbug405_init __P ((void));
void bedbug405_do_break __P ((cmd_tbl_t *, int, int, char * const []));
void bedbug405_break_isr __P ((struct pt_regs *));
int bedbug405_find_empty __P ((void));
int bedbug405_set __P ((int, unsigned long));
int bedbug405_clear __P ((int));


/* ======================================================================
 * Initialize the global bug_ctx structure for the AMCC PPC405. Clear all
 * of the breakpoints.
 * ====================================================================== */

void bedbug405_init (void)
{
        int i;

        /* -------------------------------------------------- */

        bug_ctx.hw_debug_enabled = 0;
        bug_ctx.stopped = 0;
        bug_ctx.current_bp = 0;
        bug_ctx.regs = NULL;

        bug_ctx.do_break = bedbug405_do_break;
        bug_ctx.break_isr = bedbug405_break_isr;
        bug_ctx.find_empty = bedbug405_find_empty;
        bug_ctx.set = bedbug405_set;
        bug_ctx.clear = bedbug405_clear;

        for (i = 1; i <= MAX_BREAK_POINTS; ++i)
                (*bug_ctx.clear) (i);

        puts ("BEDBUG:ready\n");
        return;
}       /* bedbug_init_breakpoints */



/* ======================================================================
 * Set/clear/show one of the hardware breakpoints for the 405.  The "off"
 * string will disable a specific breakpoint.  The "show" string will
 * display the current breakpoints.  Otherwise an address will set a
 * breakpoint at that address.  Setting a breakpoint uses the CPU-specific
 * set routine which will assign a breakpoint number.
 * ====================================================================== */

void bedbug405_do_break (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
        long addr = 0;          /* Address to break at  */
        int which_bp;           /* Breakpoint number    */

        /* -------------------------------------------------- */

        if (argc < 2) {
                cmd_usage(cmdtp);
                return;
        }

        /* Turn off a breakpoint */

        if (strcmp (argv[1], "off") == 0) {
                if (bug_ctx.hw_debug_enabled == 0) {
                        printf ("No breakpoints enabled\n");
                        return;
                }

                which_bp = simple_strtoul (argv[2], NULL, 10);

                if (bug_ctx.clear)
                        (*bug_ctx.clear) (which_bp);

                printf ("Breakpoint %d removed\n", which_bp);
                return;
        }

        /* Show a list of breakpoints */

        if (strcmp (argv[1], "show") == 0) {
                for (which_bp = 1; which_bp <= MAX_BREAK_POINTS; ++which_bp) {

                        switch (which_bp) {
                        case 1:
                                addr = GET_IAC1 ();
                                break;
                        case 2:
                                addr = GET_IAC2 ();
                                break;
                        case 3:
                                addr = GET_IAC3 ();
                                break;
                        case 4:
                                addr = GET_IAC4 ();
                                break;
                        }

                        printf ("Breakpoint [%d]: ", which_bp);
                        if (addr == 0)
                                printf ("NOT SET\n");
                        else
                                disppc ((unsigned char *) addr, 0, 1, bedbug_puts,
                                                F_RADHEX);
                }
                return;
        }

        /* Set a breakpoint at the address */

        if (!isdigit (argv[1][0])) {
                cmd_usage(cmdtp);
                return;
        }

        addr = simple_strtoul (argv[1], NULL, 16) & 0xfffffffc;

        if ((bug_ctx.set) && (which_bp = (*bug_ctx.set) (0, addr)) > 0) {
                printf ("Breakpoint [%d]: ", which_bp);
                disppc ((unsigned char *) addr, 0, 1, bedbug_puts, F_RADHEX);
        }

        return;
}       /* bedbug405_do_break */



/* ======================================================================
 * Handle a breakpoint.  First determine which breakpoint was hit by
 * looking at the DeBug Status Register (DBSR), clear the breakpoint
 * and enter a mini main loop.  Stay in the loop until the stopped flag
 * in the debug context is cleared.
 * ====================================================================== */

void bedbug405_break_isr (struct pt_regs *regs)
{
        unsigned long dbsr_val;         /* Value of the DBSR    */
        unsigned long addr = 0;         /* Address stopped at   */

        /* -------------------------------------------------- */

        dbsr_val = GET_DBSR ();

        if (dbsr_val & DBSR_IA1) {
                bug_ctx.current_bp = 1;
                addr = GET_IAC1 ();
                SET_DBSR (DBSR_IA1);    /* Write a 1 to clear */
        } else if (dbsr_val & DBSR_IA2) {
                bug_ctx.current_bp = 2;
                addr = GET_IAC2 ();
                SET_DBSR (DBSR_IA2);    /* Write a 1 to clear */
        } else if (dbsr_val & DBSR_IA3) {
                bug_ctx.current_bp = 3;
                addr = GET_IAC3 ();
                SET_DBSR (DBSR_IA3);    /* Write a 1 to clear */
        } else if (dbsr_val & DBSR_IA4) {
                bug_ctx.current_bp = 4;
                addr = GET_IAC4 ();
                SET_DBSR (DBSR_IA4);    /* Write a 1 to clear */
        }

        bedbug_main_loop (addr, regs);
        return;
}       /* bedbug405_break_isr */



/* ======================================================================
 * Look through all of the hardware breakpoints available to see if one
 * is unused.
 * ====================================================================== */

int bedbug405_find_empty (void)
{
        /* -------------------------------------------------- */

        if (GET_IAC1 () == 0)
                return 1;

        if (GET_IAC2 () == 0)
                return 2;

        if (GET_IAC3 () == 0)
                return 3;

        if (GET_IAC4 () == 0)
                return 4;

        return 0;
}       /* bedbug405_find_empty */



/* ======================================================================
 * Set a breakpoint.  If 'which_bp' is zero then find an unused breakpoint
 * number, otherwise reassign the given breakpoint.  If hardware debugging
 * is not enabled, then turn it on via the MSR and DBCR0.  Set the break
 * address in the appropriate IACx register and enable proper address
 * beakpoint in DBCR0.
 * ====================================================================== */

int bedbug405_set (int which_bp, unsigned long addr)
{
        /* -------------------------------------------------- */

        /* Only look if which_bp == 0, else use which_bp */
        if ((bug_ctx.find_empty) && (!which_bp) &&
                (which_bp = (*bug_ctx.find_empty) ()) == 0) {
                printf ("All breakpoints in use\n");
                return 0;
        }

        if (which_bp < 1 || which_bp > MAX_BREAK_POINTS) {
                printf ("Invalid break point # %d\n", which_bp);
                return 0;
        }

        if (!bug_ctx.hw_debug_enabled) {
                SET_MSR (GET_MSR () | 0x200);   /* set MSR[ DE ] */
                SET_DBCR0 (GET_DBCR0 () | DBCR0_IDM);
                bug_ctx.hw_debug_enabled = 1;
        }

        switch (which_bp) {
        case 1:
                SET_IAC1 (addr);
                SET_DBCR0 (GET_DBCR0 () | DBCR0_IA1);
                break;

        case 2:
                SET_IAC2 (addr);
                SET_DBCR0 (GET_DBCR0 () | DBCR0_IA2);
                break;

        case 3:
                SET_IAC3 (addr);
                SET_DBCR0 (GET_DBCR0 () | DBCR0_IA3);
                break;

        case 4:
                SET_IAC4 (addr);
                SET_DBCR0 (GET_DBCR0 () | DBCR0_IA4);
                break;
        }

        return which_bp;
}       /* bedbug405_set */



/* ======================================================================
 * Disable a specific breakoint by setting the appropriate IACx register
 * to zero and claring the instruction address breakpoint in DBCR0.
 * ====================================================================== */

int bedbug405_clear (int which_bp)
{
        /* -------------------------------------------------- */

        if (which_bp < 1 || which_bp > MAX_BREAK_POINTS) {
                printf ("Invalid break point # (%d)\n", which_bp);
                return -1;
        }

        switch (which_bp) {
        case 1:
                SET_IAC1 (0);
                SET_DBCR0 (GET_DBCR0 () & ~DBCR0_IA1);
                break;

        case 2:
                SET_IAC2 (0);
                SET_DBCR0 (GET_DBCR0 () & ~DBCR0_IA2);
                break;

        case 3:
                SET_IAC3 (0);
                SET_DBCR0 (GET_DBCR0 () & ~DBCR0_IA3);
                break;

        case 4:
                SET_IAC4 (0);
                SET_DBCR0 (GET_DBCR0 () & ~DBCR0_IA4);
                break;
        }

        return 0;
}       /* bedbug405_clear */


/* ====================================================================== */
#endif