/*
* (C) Copyright 2009, Texas Instruments, Inc. http://www.ti.com/
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* 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
*/
/* replicated define because linux/bitops.h cannot be included in assembly */
#define BIT(nr) (1 << (nr))
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <mach/psc.h>
#include <mach/memory.h>
#include "clock.h"
/* Arbitrary, hardware currently does not update PHYRDY correctly */
#define PHYRDY_CYCLES 0x1000
/* Assume 25 MHz speed for the cycle conversions since PLLs are bypassed */
#define PLL_BYPASS_CYCLES (PLL_BYPASS_TIME * 25)
#define PLL_RESET_CYCLES (PLL_RESET_TIME * 25)
#define PLL_LOCK_CYCLES (PLL_LOCK_TIME * 25)
#define DEEPSLEEP_SLEEPENABLE_BIT BIT(31)
.text
/*
* Move DaVinci into deep sleep state
*
* Note: This code is copied to internal SRAM by PM code. When the DaVinci
* wakes up it continues execution at the point it went to sleep.
* Register Usage:
* r0: contains virtual base for DDR2 controller
* r1: contains virtual base for DDR2 Power and Sleep controller (PSC)
* r2: contains PSC number for DDR2
* r3: contains virtual base DDR2 PLL controller
* r4: contains virtual address of the DEEPSLEEP register
*/
ENTRY(davinci_cpu_suspend)
stmfd sp!, {r0-r12, lr} @ save registers on stack
ldr ip, CACHE_FLUSH
blx ip
ldmia r0, {r0-r4}
/*
* Switch DDR to self-refresh mode.
*/
/* calculate SDRCR address */
ldr ip, [r0, #DDR2_SDRCR_OFFSET]
bic ip, ip, #DDR2_SRPD_BIT
orr ip, ip, #DDR2_LPMODEN_BIT
str ip, [r0, #DDR2_SDRCR_OFFSET]
ldr ip, [r0, #DDR2_SDRCR_OFFSET]
orr ip, ip, #DDR2_MCLKSTOPEN_BIT
str ip, [r0, #DDR2_SDRCR_OFFSET]
mov ip, #PHYRDY_CYCLES
1: subs ip, ip, #0x1
bne 1b
/* Disable DDR2 LPSC */
mov r7, r0
mov r0, #0x2
bl davinci_ddr_psc_config
mov r0, r7
/* Disable clock to DDR PHY */
ldr ip, [r3, #PLLDIV1]
bic ip, ip, #PLLDIV_EN
str ip, [r3, #PLLDIV1]
/* Put the DDR PLL in bypass and power down */
ldr ip, [r3, #PLLCTL]
bic ip, ip, #PLLCTL_PLLENSRC
bic ip, ip, #PLLCTL_PLLEN
str ip, [r3, #PLLCTL]
/* Wait for PLL to switch to bypass */
mov ip, #PLL_BYPASS_CYCLES
2: subs ip, ip, #0x1
bne 2b
/* Power down the PLL */
ldr ip, [r3, #PLLCTL]
orr ip, ip, #PLLCTL_PLLPWRDN
str ip, [r3, #PLLCTL]
/* Go to deep sleep */
ldr ip, [r4]
orr ip, ip, #DEEPSLEEP_SLEEPENABLE_BIT
/* System goes to sleep beyond after this instruction */
str ip, [r4]
/* Wake up from sleep */
/* Clear sleep enable */
ldr ip, [r4]
bic ip, ip, #DEEPSLEEP_SLEEPENABLE_BIT
str ip, [r4]
/* initialize the DDR PLL controller */
/* Put PLL in reset */
ldr ip, [r3, #PLLCTL]
bic ip, ip, #PLLCTL_PLLRST
str ip, [r3, #PLLCTL]
/* Clear PLL power down */
ldr ip, [r3, #PLLCTL]
bic ip, ip, #PLLCTL_PLLPWRDN
str ip, [r3, #PLLCTL]
mov ip, #PLL_RESET_CYCLES
3: subs ip, ip, #0x1
bne 3b
/* Bring PLL out of reset */
ldr ip, [r3, #PLLCTL]
orr ip, ip, #PLLCTL_PLLRST
str ip, [r3, #PLLCTL]
/* Wait for PLL to lock (assume prediv = 1, 25MHz OSCIN) */
mov ip, #PLL_LOCK_CYCLES
4: subs ip, ip, #0x1
bne 4b
/* Remove PLL from bypass mode */
ldr ip, [r3, #PLLCTL]
bic ip, ip, #PLLCTL_PLLENSRC
orr ip, ip, #PLLCTL_PLLEN
str ip, [r3, #PLLCTL]
/* Start 2x clock to DDR2 */
ldr ip, [r3, #PLLDIV1]
orr ip, ip, #PLLDIV_EN
str ip, [r3, #PLLDIV1]
/* Enable VCLK */
/* Enable DDR2 LPSC */
mov r7, r0
mov r0, #0x3
bl davinci_ddr_psc_config
mov r0, r7
/* clear MCLKSTOPEN */
ldr ip, [r0, #DDR2_SDRCR_OFFSET]
bic ip, ip, #DDR2_MCLKSTOPEN_BIT
str ip, [r0, #DDR2_SDRCR_OFFSET]
ldr ip, [r0, #DDR2_SDRCR_OFFSET]
bic ip, ip, #DDR2_LPMODEN_BIT
str ip, [r0, #DDR2_SDRCR_OFFSET]
/* Restore registers and return */
ldmfd sp!, {r0-r12, pc}
ENDPROC(davinci_cpu_suspend)
/*
* Disables or Enables DDR2 LPSC
* Register Usage:
* r0: Enable or Disable LPSC r0 = 0x3 => Enable, r0 = 0x2 => Disable LPSC
* r1: contains virtual base for DDR2 Power and Sleep controller (PSC)
* r2: contains PSC number for DDR2
*/
ENTRY(davinci_ddr_psc_config)
/* Set next state in mdctl for DDR2 */
mov r6, #MDCTL
add r6, r6, r2, lsl #2
ldr ip, [r1, r6]
bic ip, ip, #MDSTAT_STATE_MASK
orr ip, ip, r0
str ip, [r1, r6]
/* Enable the Power Domain Transition Command */
ldr ip, [r1, #PTCMD]
orr ip, ip, #0x1
str ip, [r1, #PTCMD]
/* Check for Transition Complete (PTSTAT) */
ptstat_done:
ldr ip, [r1, #PTSTAT]
and ip, ip, #0x1
cmp ip, #0x0
bne ptstat_done
/* Check for DDR2 clock disable completion; */
mov r6, #MDSTAT
add r6, r6, r2, lsl #2
ddr2clk_stop_done:
ldr ip, [r1, r6]
and ip, ip, #MDSTAT_STATE_MASK
cmp ip, r0
bne ddr2clk_stop_done
mov pc, lr
ENDPROC(davinci_ddr_psc_config)
CACHE_FLUSH:
.word arm926_flush_kern_cache_all
ENTRY(davinci_cpu_suspend_sz)
.word . - davinci_cpu_suspend
ENDPROC(davinci_cpu_suspend_sz)
