/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * linux/arch/arm/mach-omap2/sram243x.S
 *
 * Omap2 specific functions that need to be run in internal SRAM
 *
 * (C) Copyright 2004
 * Texas Instruments, <www.ti.com>
 * Richard Woodruff <r-woodruff2@ti.com>
 *
 * Richard Woodruff notes that any changes to this code must be carefully
 * audited and tested to ensure that they don't cause a TLB miss while
 * the SDRAM is inaccessible.  Such a situation will crash the system
 * since it will cause the ARM MMU to attempt to walk the page tables.
 * These crashes may be intermittent.
 */
#include <linux/linkage.h>

#include <asm/assembler.h>

#include "soc.h"
#include "iomap.h"
#include "prm2xxx.h"
#include "cm2xxx.h"
#include "sdrc.h"

        .text

        .align  3
ENTRY(omap243x_sram_ddr_init)
        stmfd   sp!, {r0 - r12, lr}     @ save registers on stack

        mov     r12, r2                 @ capture CS1 vs CS0
        mov     r8, r3                  @ capture force parameter

        /* frequency shift down */
        ldr     r2, omap243x_sdi_cm_clksel2_pll @ get address of dpllout reg
        mov     r3, #0x1                @ value for 1x operation
        str     r3, [r2]                @ go to L1-freq operation

        /* voltage shift down */
        mov r9, #0x1                    @ set up for L1 voltage call
        bl voltage_shift                @ go drop voltage

        /* dll lock mode */
        ldr     r11, omap243x_sdi_sdrc_dlla_ctrl        @ addr of dlla ctrl
        ldr     r10, [r11]              @ get current val
        cmp     r12, #0x1               @ cs1 base (2422 es2.05/1)
        addeq   r11, r11, #0x8          @ if cs1 base, move to DLLB
        mvn     r9, #0x4                @ mask to get clear bit2
        and     r10, r10, r9            @ clear bit2 for lock mode.
        orr     r10, r10, #0x8          @ make sure DLL on (es2 bit pos)
        orr     r10, r10, #0x2          @ 90 degree phase for all below 133MHz
        str     r10, [r11]              @ commit to DLLA_CTRL
        bl      i_dll_wait              @ wait for dll to lock

        /* get dll value */
        add     r11, r11, #0x4          @ get addr of status reg
        ldr     r10, [r11]              @ get locked value

        /* voltage shift up */
        mov r9, #0x0                    @ shift back to L0-voltage
        bl voltage_shift                @ go raise voltage

        /* frequency shift up */
        mov     r3, #0x2                @ value for 2x operation
        str     r3, [r2]                @ go to L0-freq operation

        /* reset entry mode for dllctrl */
        sub     r11, r11, #0x4          @ move from status to ctrl
        cmp     r12, #0x1               @ normalize if cs1 based
        subeq   r11, r11, #0x8          @ possibly back to DLLA
        cmp     r8, #0x1                @ if forced unlock exit
        orreq   r1, r1, #0x4            @ make sure exit with unlocked value
        str     r1, [r11]               @ restore DLLA_CTRL high value
        add     r11, r11, #0x8          @ move to DLLB_CTRL addr
        str     r1, [r11]               @ set value DLLB_CTRL
        bl      i_dll_wait              @ wait for possible lock

        /* set up for return, DDR should be good */
        str r10, [r0]                   @ write dll_status and return counter
        ldmfd   sp!, {r0 - r12, pc}     @ restore regs and return

        /* ensure the DLL has relocked */
i_dll_wait:
        mov     r4, #0x800              @ delay DLL relock, min 0x400 L3 clocks
i_dll_delay:
        subs    r4, r4, #0x1
        bne     i_dll_delay
        ret     lr

        /*
         * shift up or down voltage, use R9 as input to tell level.
         * wait for it to finish, use 32k sync counter, 1tick=31uS.
         */
voltage_shift:
        ldr     r4, omap243x_sdi_prcm_voltctrl  @ get addr of volt ctrl.
        ldr     r5, [r4]                @ get value.
        ldr     r6, prcm_mask_val       @ get value of mask
        and     r5, r5, r6              @ apply mask to clear bits
        orr     r5, r5, r9              @ bulld value for L0/L1-volt operation.
        str     r5, [r4]                @ set up for change.
        mov     r3, #0x4000             @ get val for force
        orr     r5, r5, r3              @ build value for force
        str     r5, [r4]                @ Force transition to L1

        ldr     r3, omap243x_sdi_timer_32ksynct_cr      @ get addr of counter
        ldr     r5, [r3]                @ get value
        add     r5, r5, #0x3            @ give it at most 93uS
volt_delay:
        ldr     r7, [r3]                @ get timer value
        cmp     r5, r7                  @ time up?
        bhi     volt_delay              @ not yet->branch
        ret     lr                      @ back to caller.

omap243x_sdi_cm_clksel2_pll:
        .word OMAP2430_CM_REGADDR(PLL_MOD, CM_CLKSEL2)
omap243x_sdi_sdrc_dlla_ctrl:
        .word OMAP243X_SDRC_REGADDR(SDRC_DLLA_CTRL)
omap243x_sdi_prcm_voltctrl:
        .word OMAP2430_PRCM_VOLTCTRL
prcm_mask_val:
        .word 0xFFFF3FFC
omap243x_sdi_timer_32ksynct_cr:
        .word OMAP2_L4_IO_ADDRESS(OMAP2430_32KSYNCT_BASE + 0x010)
ENTRY(omap243x_sram_ddr_init_sz)
        .word   . - omap243x_sram_ddr_init

/*
 * Reprograms memory timings.
 * r0 = [PRCM_FULL | PRCM_HALF] r1 = SDRC_DLLA_CTRL value r2 = [DDR | SDR]
 * PRCM_FULL = 2, PRCM_HALF = 1, DDR = 1, SDR = 0
 */
        .align  3
ENTRY(omap243x_sram_reprogram_sdrc)
        stmfd   sp!, {r0 - r10, lr}     @ save registers on stack
        mov     r3, #0x0                @ clear for mrc call
        mcr     p15, 0, r3, c7, c10, 4  @ memory barrier, finish ARM SDR/DDR
        nop
        nop
        ldr     r6, omap243x_srs_sdrc_rfr_ctrl  @ get addr of refresh reg
        ldr     r5, [r6]                @ get value
        mov     r5, r5, lsr #8          @ isolate rfr field and drop burst

        cmp     r0, #0x1                @ going to half speed?
        movne   r9, #0x0                @ if up set flag up for pre up, hi volt

        blne    voltage_shift_c         @ adjust voltage

        cmp     r0, #0x1                @ going to half speed (post branch link)
        moveq   r5, r5, lsr #1          @ divide by 2 if to half
        movne   r5, r5, lsl #1          @ mult by 2 if to full
        mov     r5, r5, lsl #8          @ put rfr field back into place
        add     r5, r5, #0x1            @ turn on burst of 1
        ldr     r4, omap243x_srs_cm_clksel2_pll @ get address of out reg
        ldr     r3, [r4]                @ get curr value
        orr     r3, r3, #0x3
        bic     r3, r3, #0x3            @ clear lower bits
        orr     r3, r3, r0              @ new state value
        str     r3, [r4]                @ set new state (pll/x, x=1 or 2)
        nop
        nop

        moveq   r9, #0x1                @ if speed down, post down, drop volt
        bleq    voltage_shift_c

        mcr     p15, 0, r3, c7, c10, 4  @ memory barrier
        str     r5, [r6]                @ set new RFR_1 value
        add     r6, r6, #0x30           @ get RFR_2 addr
        str     r5, [r6]                @ set RFR_2
        nop
        cmp     r2, #0x1                @ (SDR or DDR) do we need to adjust DLL
        bne     freq_out                @ leave if SDR, no DLL function

        /* With DDR, we need to take care of the DLL for the frequency change */
        ldr     r2, omap243x_srs_sdrc_dlla_ctrl @ addr of dlla ctrl
        str     r1, [r2]                @ write out new SDRC_DLLA_CTRL
        add     r2, r2, #0x8            @ addr to SDRC_DLLB_CTRL
        str     r1, [r2]                @ commit to SDRC_DLLB_CTRL
        mov     r1, #0x2000             @ wait DLL relock, min 0x400 L3 clocks
dll_wait:
        subs    r1, r1, #0x1
        bne     dll_wait
freq_out:
        ldmfd   sp!, {r0 - r10, pc}     @ restore regs and return

    /*
     * shift up or down voltage, use R9 as input to tell level.
     *  wait for it to finish, use 32k sync counter, 1tick=31uS.
     */
voltage_shift_c:
        ldr     r10, omap243x_srs_prcm_voltctrl @ get addr of volt ctrl
        ldr     r8, [r10]               @ get value
        ldr     r7, ddr_prcm_mask_val   @ get value of mask
        and     r8, r8, r7              @ apply mask to clear bits
        orr     r8, r8, r9              @ bulld value for L0/L1-volt operation.
        str     r8, [r10]               @ set up for change.
        mov     r7, #0x4000             @ get val for force
        orr     r8, r8, r7              @ build value for force
        str     r8, [r10]               @ Force transition to L1

        ldr     r10, omap243x_srs_timer_32ksynct        @ get addr of counter
        ldr     r8, [r10]               @ get value
        add     r8, r8, #0x2            @ give it at most 62uS (min 31+)
volt_delay_c:
        ldr     r7, [r10]               @ get timer value
        cmp     r8, r7                  @ time up?
        bhi     volt_delay_c            @ not yet->branch
        ret     lr                      @ back to caller

omap243x_srs_cm_clksel2_pll:
        .word OMAP2430_CM_REGADDR(PLL_MOD, CM_CLKSEL2)
omap243x_srs_sdrc_dlla_ctrl:
        .word OMAP243X_SDRC_REGADDR(SDRC_DLLA_CTRL)
omap243x_srs_sdrc_rfr_ctrl:
        .word OMAP243X_SDRC_REGADDR(SDRC_RFR_CTRL_0)
omap243x_srs_prcm_voltctrl:
        .word OMAP2430_PRCM_VOLTCTRL
ddr_prcm_mask_val:
        .word 0xFFFF3FFC
omap243x_srs_timer_32ksynct:
        .word OMAP2_L4_IO_ADDRESS(OMAP2430_32KSYNCT_BASE + 0x010)

ENTRY(omap243x_sram_reprogram_sdrc_sz)
        .word   . - omap243x_sram_reprogram_sdrc

/*
 * Set dividers and pll. Also recalculate DLL value for DDR and unlock mode.
 */
        .align  3
ENTRY(omap243x_sram_set_prcm)
        stmfd   sp!, {r0-r12, lr}       @ regs to stack
        adr     r4, pbegin              @ addr of preload start
        adr     r8, pend                @ addr of preload end
        mcrr    p15, 1, r8, r4, c12     @ preload into icache
pbegin:
        /* move into fast relock bypass */
        ldr     r8, omap243x_ssp_pll_ctl        @ get addr
        ldr     r5, [r8]                @ get val
        mvn     r6, #0x3                @ clear mask
        and     r5, r5, r6              @ clear field
        orr     r7, r5, #0x2            @ fast relock val
        str     r7, [r8]                @ go to fast relock
        ldr     r4, omap243x_ssp_pll_stat       @ addr of stat
block:
        /* wait for bypass */
        ldr     r8, [r4]                @ stat value
        and     r8, r8, #0x3            @ mask for stat
        cmp     r8, #0x1                @ there yet
        bne     block                   @ loop if not

        /* set new dpll dividers _after_ in bypass */
        ldr     r4, omap243x_ssp_pll_div        @ get addr
        str     r0, [r4]                @ set dpll ctrl val

        ldr     r4, omap243x_ssp_set_config     @ get addr
        mov     r8, #1                  @ valid cfg msk
        str     r8, [r4]                @ make dividers take

        mov     r4, #100                @ dead spin a bit
wait_a_bit:
        subs    r4, r4, #1              @ dec loop
        bne     wait_a_bit              @ delay done?

        /* check if staying in bypass */
        cmp     r2, #0x1                @ stay in bypass?
        beq     pend                    @ jump over dpll relock

        /* relock DPLL with new vals */
        ldr     r5, omap243x_ssp_pll_stat       @ get addr
        ldr     r4, omap243x_ssp_pll_ctl        @ get addr
        orr     r8, r7, #0x3            @ val for lock dpll
        str     r8, [r4]                @ set val
        mov     r0, #1000               @ dead spin a bit
wait_more:
        subs    r0, r0, #1              @ dec loop
        bne     wait_more               @ delay done?
wait_lock:
        ldr     r8, [r5]                @ get lock val
        and     r8, r8, #3              @ isolate field
        cmp     r8, #2                  @ locked?
        bne     wait_lock               @ wait if not
pend:
        /* update memory timings & briefly lock dll */
        ldr     r4, omap243x_ssp_sdrc_rfr       @ get addr
        str     r1, [r4]                @ update refresh timing
        ldr     r11, omap243x_ssp_dlla_ctrl     @ get addr of DLLA ctrl
        ldr     r10, [r11]              @ get current val
        mvn     r9, #0x4                @ mask to get clear bit2
        and     r10, r10, r9            @ clear bit2 for lock mode
        orr     r10, r10, #0x8          @ make sure DLL on (es2 bit pos)
        str     r10, [r11]              @ commit to DLLA_CTRL
        add     r11, r11, #0x8          @ move to dllb
        str     r10, [r11]              @ hit DLLB also

        mov     r4, #0x800              @ relock time (min 0x400 L3 clocks)
wait_dll_lock:
        subs    r4, r4, #0x1
        bne     wait_dll_lock
        nop
        ldmfd   sp!, {r0-r12, pc}       @ restore regs and return

omap243x_ssp_set_config:
        .word OMAP2430_PRCM_CLKCFG_CTRL
omap243x_ssp_pll_ctl:
        .word OMAP2430_CM_REGADDR(PLL_MOD, CM_CLKEN)
omap243x_ssp_pll_stat:
        .word OMAP2430_CM_REGADDR(PLL_MOD, CM_IDLEST)
omap243x_ssp_pll_div:
        .word OMAP2430_CM_REGADDR(PLL_MOD, CM_CLKSEL1)
omap243x_ssp_sdrc_rfr:
        .word OMAP243X_SDRC_REGADDR(SDRC_RFR_CTRL_0)
omap243x_ssp_dlla_ctrl:
        .word OMAP243X_SDRC_REGADDR(SDRC_DLLA_CTRL)

ENTRY(omap243x_sram_set_prcm_sz)
        .word   . - omap243x_sram_set_prcm