/*
* linux/arch/arm/mach-omap3/sram.S
*
* Omap3 specific functions that need to be run in internal SRAM
*
* Copyright (C) 2004, 2007, 2008 Texas Instruments, Inc.
* Copyright (C) 2008 Nokia Corporation
*
* Rajendra Nayak <rnayak@ti.com>
* Richard Woodruff <r-woodruff2@ti.com>
* Paul Walmsley
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR /PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <mach/hardware.h>
#include "iomap.h"
#include "sdrc.h"
#include "cm2xxx_3xxx.h"
/*
* This file needs be built unconditionally as ARM to interoperate correctly
* with non-Thumb-2-capable firmware.
*/
.arm
.text
/* r1 parameters */
#define SDRC_NO_UNLOCK_DLL 0x0
#define SDRC_UNLOCK_DLL 0x1
/* SDRC_DLLA_CTRL bit settings */
#define FIXEDDELAY_SHIFT 24
#define FIXEDDELAY_MASK (0xff << FIXEDDELAY_SHIFT)
#define DLLIDLE_MASK 0x4
/*
* SDRC_DLLA_CTRL default values: TI hardware team indicates that
* FIXEDDELAY should be initialized to 0xf. This apparently was
* empirically determined during process testing, so no derivation
* was provided.
*/
#define FIXEDDELAY_DEFAULT (0x0f << FIXEDDELAY_SHIFT)
/* SDRC_DLLA_STATUS bit settings */
#define LOCKSTATUS_MASK 0x4
/* SDRC_POWER bit settings */
#define SRFRONIDLEREQ_MASK 0x40
/* CM_IDLEST1_CORE bit settings */
#define ST_SDRC_MASK 0x2
/* CM_ICLKEN1_CORE bit settings */
#define EN_SDRC_MASK 0x2
/* CM_CLKSEL1_PLL bit settings */
#define CORE_DPLL_CLKOUT_DIV_SHIFT 0x1b
/*
* omap3_sram_configure_core_dpll - change DPLL3 M2 divider
*
* Params passed in registers:
* r0 = new M2 divider setting (only 1 and 2 supported right now)
* r1 = unlock SDRC DLL? (1 = yes, 0 = no). Only unlock DLL for
* SDRC rates < 83MHz
* r2 = number of MPU cycles to wait for SDRC to stabilize after
* reprogramming the SDRC when switching to a slower MPU speed
* r3 = increasing SDRC rate? (1 = yes, 0 = no)
*
* Params passed via the stack. The needed params will be copied in SRAM
* before use by the code in SRAM (SDRAM is not accessible during SDRC
* reconfiguration):
* new SDRC_RFR_CTRL_0 register contents
* new SDRC_ACTIM_CTRL_A_0 register contents
* new SDRC_ACTIM_CTRL_B_0 register contents
* new SDRC_MR_0 register value
* new SDRC_RFR_CTRL_1 register contents
* new SDRC_ACTIM_CTRL_A_1 register contents
* new SDRC_ACTIM_CTRL_B_1 register contents
* new SDRC_MR_1 register value
*
* If the param SDRC_RFR_CTRL_1 is 0, the parameters are not programmed into
* the SDRC CS1 registers
*
* NOTE: This code no longer attempts to program the SDRC AC timing and MR
* registers. This is because the code currently cannot ensure that all
* L3 initiators (e.g., sDMA, IVA, DSS DISPC, etc.) are not accessing the
* SDRAM when the registers are written. If the registers are changed while
* an initiator is accessing SDRAM, memory can be corrupted and/or the SDRC
* may enter an unpredictable state. In the future, the intent is to
* re-enable this code in cases where we can ensure that no initiators are
* touching the SDRAM. Until that time, users who know that their use case
* can satisfy the above requirement can enable the CONFIG_OMAP3_SDRC_AC_TIMING
* option.
*
* 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.
*/
.align 3
ENTRY(omap3_sram_configure_core_dpll)
stmfd sp!, {r1-r12, lr} @ store regs to stack
@ pull the extra args off the stack
@ and store them in SRAM
/*
* PC-relative stores are deprecated in ARMv7 and lead to undefined behaviour
* in Thumb-2: use a r7 as a base instead.
* Be careful not to clobber r7 when maintaing this file.
*/
THUMB( adr r7, omap3_sram_configure_core_dpll )
.macro strtext Rt:req, label:req
ARM( str \Rt, \label )
THUMB( str \Rt, [r7, \label - omap3_sram_configure_core_dpll] )
.endm
ldr r4, [sp, #52]
strtext r4, omap_sdrc_rfr_ctrl_0_val
ldr r4, [sp, #56]
strtext r4, omap_sdrc_actim_ctrl_a_0_val
ldr r4, [sp, #60]
strtext r4, omap_sdrc_actim_ctrl_b_0_val
ldr r4, [sp, #64]
strtext r4, omap_sdrc_mr_0_val
ldr r4, [sp, #68]
strtext r4, omap_sdrc_rfr_ctrl_1_val
cmp r4, #0 @ if SDRC_RFR_CTRL_1 is 0,
beq skip_cs1_params @ do not use cs1 params
ldr r4, [sp, #72]
strtext r4, omap_sdrc_actim_ctrl_a_1_val
ldr r4, [sp, #76]
strtext r4, omap_sdrc_actim_ctrl_b_1_val
ldr r4, [sp, #80]
strtext r4, omap_sdrc_mr_1_val
skip_cs1_params:
mrc p15, 0, r8, c1, c0, 0 @ read ctrl register
bic r10, r8, #0x800 @ clear Z-bit, disable branch prediction
mcr p15, 0, r10, c1, c0, 0 @ write ctrl register
dsb @ flush buffered writes to interconnect
isb @ prevent speculative exec past here
cmp r3, #1 @ if increasing SDRC clk rate,
bleq configure_sdrc @ program the SDRC regs early (for RFR)
cmp r1, #SDRC_UNLOCK_DLL @ set the intended DLL state
bleq unlock_dll
blne lock_dll
bl sdram_in_selfrefresh @ put SDRAM in self refresh, idle SDRC
bl configure_core_dpll @ change the DPLL3 M2 divider
mov r12, r2
bl wait_clk_stable @ wait for SDRC to stabilize
bl enable_sdrc @ take SDRC out of idle
cmp r1, #SDRC_UNLOCK_DLL @ wait for DLL status to change
bleq wait_dll_unlock
blne wait_dll_lock
cmp r3, #1 @ if increasing SDRC clk rate,
beq return_to_sdram @ return to SDRAM code, otherwise,
bl configure_sdrc @ reprogram SDRC regs now
return_to_sdram:
mcr p15, 0, r8, c1, c0, 0 @ restore ctrl register
isb @ prevent speculative exec past here
mov r0, #0 @ return value
ldmfd sp!, {r1-r12, pc} @ restore regs and return
unlock_dll:
ldr r11, omap3_sdrc_dlla_ctrl
ldr r12, [r11]
bic r12, r12, #FIXEDDELAY_MASK
orr r12, r12, #FIXEDDELAY_DEFAULT
orr r12, r12, #DLLIDLE_MASK
str r12, [r11] @ (no OCP barrier needed)
bx lr
lock_dll:
ldr r11, omap3_sdrc_dlla_ctrl
ldr r12, [r11]
bic r12, r12, #DLLIDLE_MASK
str r12, [r11] @ (no OCP barrier needed)
bx lr
sdram_in_selfrefresh:
ldr r11, omap3_sdrc_power @ read the SDRC_POWER register
ldr r12, [r11] @ read the contents of SDRC_POWER
mov r9, r12 @ keep a copy of SDRC_POWER bits
orr r12, r12, #SRFRONIDLEREQ_MASK @ enable self refresh on idle
str r12, [r11] @ write back to SDRC_POWER register
ldr r12, [r11] @ posted-write barrier for SDRC
idle_sdrc:
ldr r11, omap3_cm_iclken1_core @ read the CM_ICLKEN1_CORE reg
ldr r12, [r11]
bic r12, r12, #EN_SDRC_MASK @ disable iclk bit for SDRC
str r12, [r11]
wait_sdrc_idle:
ldr r11, omap3_cm_idlest1_core
ldr r12, [r11]
and r12, r12, #ST_SDRC_MASK @ check for SDRC idle
cmp r12, #ST_SDRC_MASK
bne wait_sdrc_idle
bx lr
configure_core_dpll:
ldr r11, omap3_cm_clksel1_pll
ldr r12, [r11]
ldr r10, core_m2_mask_val @ modify m2 for core dpll
and r12, r12, r10
orr r12, r12, r0, lsl #CORE_DPLL_CLKOUT_DIV_SHIFT
str r12, [r11]
ldr r12, [r11] @ posted-write barrier for CM
bx lr
wait_clk_stable:
subs r12, r12, #1
bne wait_clk_stable
bx lr
enable_sdrc:
ldr r11, omap3_cm_iclken1_core
ldr r12, [r11]
orr r12, r12, #EN_SDRC_MASK @ enable iclk bit for SDRC
str r12, [r11]
wait_sdrc_idle1:
ldr r11, omap3_cm_idlest1_core
ldr r12, [r11]
and r12, r12, #ST_SDRC_MASK
cmp r12, #0
bne wait_sdrc_idle1
restore_sdrc_power_val:
ldr r11, omap3_sdrc_power
str r9, [r11] @ restore SDRC_POWER, no barrier needed
bx lr
wait_dll_lock:
ldr r11, omap3_sdrc_dlla_status
ldr r12, [r11]
and r12, r12, #LOCKSTATUS_MASK
cmp r12, #LOCKSTATUS_MASK
bne wait_dll_lock
bx lr
wait_dll_unlock:
ldr r11, omap3_sdrc_dlla_status
ldr r12, [r11]
and r12, r12, #LOCKSTATUS_MASK
cmp r12, #0x0
bne wait_dll_unlock
bx lr
configure_sdrc:
ldr r12, omap_sdrc_rfr_ctrl_0_val @ fetch value from SRAM
ldr r11, omap3_sdrc_rfr_ctrl_0 @ fetch addr from SRAM
str r12, [r11] @ store
#ifdef CONFIG_OMAP3_SDRC_AC_TIMING
ldr r12, omap_sdrc_actim_ctrl_a_0_val
ldr r11, omap3_sdrc_actim_ctrl_a_0
str r12, [r11]
ldr r12, omap_sdrc_actim_ctrl_b_0_val
ldr r11, omap3_sdrc_actim_ctrl_b_0
str r12, [r11]
ldr r12, omap_sdrc_mr_0_val
ldr r11, omap3_sdrc_mr_0
str r12, [r11]
#endif
ldr r12, omap_sdrc_rfr_ctrl_1_val
cmp r12, #0 @ if SDRC_RFR_CTRL_1 is 0,
beq skip_cs1_prog @ do not program cs1 params
ldr r11, omap3_sdrc_rfr_ctrl_1
str r12, [r11]
#ifdef CONFIG_OMAP3_SDRC_AC_TIMING
ldr r12, omap_sdrc_actim_ctrl_a_1_val
ldr r11, omap3_sdrc_actim_ctrl_a_1
str r12, [r11]
ldr r12, omap_sdrc_actim_ctrl_b_1_val
ldr r11, omap3_sdrc_actim_ctrl_b_1
str r12, [r11]
ldr r12, omap_sdrc_mr_1_val
ldr r11, omap3_sdrc_mr_1
str r12, [r11]
#endif
skip_cs1_prog:
ldr r12, [r11] @ posted-write barrier for SDRC
bx lr
.align
omap3_sdrc_power:
.word OMAP34XX_SDRC_REGADDR(SDRC_POWER)
omap3_cm_clksel1_pll:
.word OMAP34XX_CM_REGADDR(PLL_MOD, CM_CLKSEL1)
omap3_cm_idlest1_core:
.word OMAP34XX_CM_REGADDR(CORE_MOD, CM_IDLEST)
omap3_cm_iclken1_core:
.word OMAP34XX_CM_REGADDR(CORE_MOD, CM_ICLKEN1)
omap3_sdrc_rfr_ctrl_0:
.word OMAP34XX_SDRC_REGADDR(SDRC_RFR_CTRL_0)
omap3_sdrc_rfr_ctrl_1:
.word OMAP34XX_SDRC_REGADDR(SDRC_RFR_CTRL_1)
omap3_sdrc_actim_ctrl_a_0:
.word OMAP34XX_SDRC_REGADDR(SDRC_ACTIM_CTRL_A_0)
omap3_sdrc_actim_ctrl_a_1:
.word OMAP34XX_SDRC_REGADDR(SDRC_ACTIM_CTRL_A_1)
omap3_sdrc_actim_ctrl_b_0:
.word OMAP34XX_SDRC_REGADDR(SDRC_ACTIM_CTRL_B_0)
omap3_sdrc_actim_ctrl_b_1:
.word OMAP34XX_SDRC_REGADDR(SDRC_ACTIM_CTRL_B_1)
omap3_sdrc_mr_0:
.word OMAP34XX_SDRC_REGADDR(SDRC_MR_0)
omap3_sdrc_mr_1:
.word OMAP34XX_SDRC_REGADDR(SDRC_MR_1)
omap_sdrc_rfr_ctrl_0_val:
.word 0xDEADBEEF
omap_sdrc_rfr_ctrl_1_val:
.word 0xDEADBEEF
omap_sdrc_actim_ctrl_a_0_val:
.word 0xDEADBEEF
omap_sdrc_actim_ctrl_a_1_val:
.word 0xDEADBEEF
omap_sdrc_actim_ctrl_b_0_val:
.word 0xDEADBEEF
omap_sdrc_actim_ctrl_b_1_val:
.word 0xDEADBEEF
omap_sdrc_mr_0_val:
.word 0xDEADBEEF
omap_sdrc_mr_1_val:
.word 0xDEADBEEF
omap3_sdrc_dlla_status:
.word OMAP34XX_SDRC_REGADDR(SDRC_DLLA_STATUS)
omap3_sdrc_dlla_ctrl:
.word OMAP34XX_SDRC_REGADDR(SDRC_DLLA_CTRL)
core_m2_mask_val:
.word 0x07FFFFFF
ENDPROC(omap3_sram_configure_core_dpll)
ENTRY(omap3_sram_configure_core_dpll_sz)
.word . - omap3_sram_configure_core_dpll
