linux/arch/arm/mach-omap2/sram34xx.S
Paul Walmsley 6adb8f388e OMAP3 clock: remove wait for DPLL3 M2 clock to stabilize
The original CDP kernel that this code comes from waited for 0x800
loops after switching the CORE DPLL M2 divider.  This does not appear
to be necessary.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
2009-06-19 19:09:30 -06:00

182 lines
4.7 KiB
ArmAsm

/*
* linux/arch/arm/mach-omap3/sram.S
*
* Omap3 specific functions that need to be run in internal SRAM
*
* (C) Copyright 2007
* Texas Instruments Inc.
* Rajendra Nayak <rnayak@ti.com>
*
* (C) Copyright 2004
* Texas Instruments, <www.ti.com>
* Richard Woodruff <r-woodruff2@ti.com>
*
* 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 <mach/io.h>
#include "sdrc.h"
#include "cm.h"
.text
/*
* Change frequency of core dpll
* r0 = sdrc_rfr_ctrl r1 = sdrc_actim_ctrla r2 = sdrc_actim_ctrlb r3 = M2
* r4 = Unlock SDRC DLL? (1 = yes, 0 = no) -- only unlock DLL for
* SDRC rates < 83MHz
*/
ENTRY(omap3_sram_configure_core_dpll)
stmfd sp!, {r1-r12, lr} @ store regs to stack
ldr r4, [sp, #52] @ pull extra args off the stack
dsb @ flush buffered writes to interconnect
cmp r3, #0x2
blne configure_sdrc
cmp r4, #0x1
bleq unlock_dll
blne lock_dll
bl sdram_in_selfrefresh @ put the SDRAM in self refresh
bl configure_core_dpll
bl enable_sdrc
cmp r4, #0x1
bleq wait_dll_unlock
blne wait_dll_lock
cmp r3, #0x1
blne configure_sdrc
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]
orr r12, r12, #0x4
str r12, [r11] @ (no OCP barrier needed)
bx lr
lock_dll:
ldr r11, omap3_sdrc_dlla_ctrl
ldr r12, [r11]
bic r12, r12, #0x4
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, #0x40 @ enable self refresh on idle req
bic r12, r12, #0x4 @ clear PWDENA
str r12, [r11] @ write back to SDRC_POWER register
ldr r12, [r11] @ posted-write barrier for SDRC
ldr r11, omap3_cm_iclken1_core @ read the CM_ICLKEN1_CORE reg
ldr r12, [r11]
bic r12, r12, #0x2 @ disable iclk bit for SDRC
str r12, [r11]
wait_sdrc_idle:
ldr r11, omap3_cm_idlest1_core
ldr r12, [r11]
and r12, r12, #0x2 @ check for SDRC idle
cmp r12, #2
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, r3, lsl #0x1B @ r3 contains the M2 val
str r12, [r11]
ldr r12, [r11] @ posted-write barrier for CM
bx lr
wait_clk_stable:
subs r12, r12, #1
bne wait_clk_stable
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
bx lr
enable_sdrc:
ldr r11, omap3_cm_iclken1_core
ldr r12, [r11]
orr r12, r12, #0x2 @ enable iclk bit for SDRC
str r12, [r11]
wait_sdrc_idle1:
ldr r11, omap3_cm_idlest1_core
ldr r12, [r11]
and r12, r12, #0x2
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, #0x4
cmp r12, #0x4
bne wait_dll_lock
bx lr
wait_dll_unlock:
ldr r11, omap3_sdrc_dlla_status
ldr r12, [r11]
and r12, r12, #0x4
cmp r12, #0x0
bne wait_dll_unlock
bx lr
configure_sdrc:
ldr r11, omap3_sdrc_rfr_ctrl
str r0, [r11]
ldr r11, omap3_sdrc_actim_ctrla
str r1, [r11]
ldr r11, omap3_sdrc_actim_ctrlb
str r2, [r11]
ldr r2, [r11] @ posted-write barrier for SDRC
bx lr
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:
.word OMAP34XX_SDRC_REGADDR(SDRC_RFR_CTRL_0)
omap3_sdrc_actim_ctrla:
.word OMAP34XX_SDRC_REGADDR(SDRC_ACTIM_CTRL_A_0)
omap3_sdrc_actim_ctrlb:
.word OMAP34XX_SDRC_REGADDR(SDRC_ACTIM_CTRL_B_0)
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
ENTRY(omap3_sram_configure_core_dpll_sz)
.word . - omap3_sram_configure_core_dpll