/*
   * 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>
   *
   * 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
   *
   * 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
  	mov	pc, 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
  	mov	pc, 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
  	mov	pc, 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