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linux/arch/arm/mach-omap2/sram34xx.S
Paul Walmsley 7b7bcefa35 OMAP3 SDRC: set FIXEDDELAY when disabling SDRC DLL 
Correspondence with the TI OMAP hardware team indicates that
SDRC_DLLA_CTRL.FIXEDDELAY should be initialized to 0x0f.  This number
was apparently derived from process validation.  This is only used
when the SDRC DLL is unlocked (e.g., SDRC clock frequency less than
83MHz).

Signed-off-by: Paul Walmsley <paul@pwsan.com>
2009-06-19 19:09:32 -06:00

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6.7 KiB
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/*
* 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 <mach/io.h>
#include "sdrc.h"
#include "cm.h"
.text
/* r4 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
#define PWDENA_MASK 0x4
/* 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
* r0 = new SDRC_RFR_CTRL register contents
* r1 = new SDRC_ACTIM_CTRLA register contents
* r2 = new SDRC_ACTIM_CTRLB register contents
* r3 = new M2 divider setting (only 1 and 2 supported right now)
* r4 = unlock SDRC DLL? (1 = yes, 0 = no). Only unlock DLL for
* SDRC rates < 83MHz
* r5 = number of MPU cycles to wait for SDRC to stabilize after
* reprogramming the SDRC when switching to a slower MPU speed
* r6 = new SDRC_MR_0 register value
* r7 = increasing SDRC rate? (1 = yes, 0 = no)
*
*/
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
ldr r5, [sp, #56] @ load extra args from the stack
ldr r6, [sp, #60] @ load extra args from the stack
ldr r7, [sp, #64] @ load extra args from the stack
dsb @ flush buffered writes to interconnect
cmp r7, #1 @ if increasing SDRC clk rate,
bleq configure_sdrc @ program the SDRC regs early (for RFR)
cmp r4, #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
bl enable_sdrc @ take SDRC out of idle
cmp r4, #SDRC_UNLOCK_DLL @ wait for DLL status to change
bleq wait_dll_unlock
blne wait_dll_lock
cmp r7, #1 @ if increasing SDRC clk rate,
beq return_to_sdram @ return to SDRAM code, otherwise,
bl configure_sdrc @ reprogram SDRC regs now
mov r12, r5
bl wait_clk_stable @ wait for SDRC to stabilize
return_to_sdram:
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]
and 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
bic r12, r12, #PWDENA_MASK @ clear PWDENA
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, r3, 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 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 r11, omap3_sdrc_mr_0
str r6, [r11]
ldr r6, [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_mr_0:
.word OMAP34XX_SDRC_REGADDR(SDRC_MR_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
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