/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* linux/arch/arm/mach-omap2/sram242x.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(omap242x_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, omap242x_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, omap242x_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, omap242x_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, omap242x_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.
omap242x_sdi_cm_clksel2_pll:
.
word OMAP2420_CM_REGADDR(PLL_MOD, CM_CLKSEL2)
omap242x_sdi_sdrc_dlla_ctrl:
.
word OMAP242X_SDRC_REGADDR(SDRC_DLLA_CTRL)
omap242x_sdi_prcm_voltctrl:
.
word OMAP2420_PRCM_VOLTCTRL
prcm_mask_val:
.
word 0xFFFF3FFC
omap242x_sdi_timer_32ksynct_cr:
.
word OMAP2_L4_IO_ADDRESS(OMAP2420_32KSYNCT_BASE + 0x010)
ENTRY(omap242x_sram_ddr_init_sz)
.
word . - omap242x_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(omap242x_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, omap242x_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, omap242x_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, omap242x_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, omap242x_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, omap242x_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
omap242x_srs_cm_clksel2_pll:
.
word OMAP2420_CM_REGADDR(PLL_MOD, CM_CLKSEL2)
omap242x_srs_sdrc_dlla_ctrl:
.
word OMAP242X_SDRC_REGADDR(SDRC_DLLA_CTRL)
omap242x_srs_sdrc_rfr_ctrl:
.
word OMAP242X_SDRC_REGADDR(SDRC_RFR_CTRL_0)
omap242x_srs_prcm_voltctrl:
.
word OMAP2420_PRCM_VOLTCTRL
ddr_prcm_mask_val:
.
word 0xFFFF3FFC
omap242x_srs_timer_32ksynct:
.
word OMAP2_L4_IO_ADDRESS(OMAP2420_32KSYNCT_BASE + 0x010)
ENTRY(omap242x_sram_reprogram_sdrc_sz)
.
word . - omap242x_sram_reprogram_sdrc
/*
* Set dividers and pll. Also recalculate DLL value for DDR and unlock mode.
*/
.
align 3
ENTRY(omap242x_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, omap242x_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, omap242x_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, omap242x_ssp_pll_div @ get addr
str r0, [r4] @
set dpll ctrl val
ldr r4, omap242x_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, omap242x_ssp_pll_stat @ get addr
ldr r4, omap242x_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, omap242x_ssp_sdrc_rfr @ get addr
str r1, [r4] @ update refresh timing
ldr r11, omap242x_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
omap242x_ssp_set_config:
.
word OMAP2420_PRCM_CLKCFG_CTRL
omap242x_ssp_pll_ctl:
.
word OMAP2420_CM_REGADDR(PLL_MOD, CM_CLKEN)
omap242x_ssp_pll_stat:
.
word OMAP2420_CM_REGADDR(PLL_MOD, CM_IDLEST)
omap242x_ssp_pll_div:
.
word OMAP2420_CM_REGADDR(PLL_MOD, CM_CLKSEL1)
omap242x_ssp_sdrc_rfr:
.
word OMAP242X_SDRC_REGADDR(SDRC_RFR_CTRL_0)
omap242x_ssp_dlla_ctrl:
.
word OMAP242X_SDRC_REGADDR(SDRC_DLLA_CTRL)
ENTRY(omap242x_sram_set_prcm_sz)
.
word . - omap242x_sram_set_prcm
