arch/arm/mach-at91/pm_suspend.S

   1 /*
   2  * arch/arm/mach-at91/pm_slow_clock.S
   3  *
   4  *  Copyright (C) 2006 Savin Zlobec
   5  *
   6  * AT91SAM9 support:
   7  *  Copyright (C) 2007 Anti Sullin <anti.sullin@artecdesign.ee>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  */
  14 #include <linux/linkage.h>
  15 #include <linux/clk/at91_pmc.h>
  16 #include "pm.h"
  17 #include "generated/at91_pm_data-offsets.h"
  18
  19 #define SRAMC_SELF_FRESH_ACTIVE         0x01
  20 #define SRAMC_SELF_FRESH_EXIT           0x00
  21
  22 pmc     .req    r0
  23 tmp1    .req    r4
  24 tmp2    .req    r5
  25
  26 /*
  27  * Wait until master clock is ready (after switching master clock source)
  28  */
  29         .macro wait_mckrdy
  30 1:      ldr     tmp1, [pmc, #AT91_PMC_SR]
  31         tst     tmp1, #AT91_PMC_MCKRDY
  32         beq     1b
  33         .endm
  34
  35 /*
  36  * Wait until master oscillator has stabilized.
  37  */
  38         .macro wait_moscrdy
  39 1:      ldr     tmp1, [pmc, #AT91_PMC_SR]
  40         tst     tmp1, #AT91_PMC_MOSCS
  41         beq     1b
  42         .endm
  43
  44 /*
  45  * Wait until PLLA has locked.
  46  */
  47         .macro wait_pllalock
  48 1:      ldr     tmp1, [pmc, #AT91_PMC_SR]
  49         tst     tmp1, #AT91_PMC_LOCKA
  50         beq     1b
  51         .endm
  52
  53 /*
  54  * Put the processor to enter the idle state
  55  */
  56         .macro at91_cpu_idle
  57
  58 #if defined(CONFIG_CPU_V7)
  59         mov     tmp1, #AT91_PMC_PCK
  60         str     tmp1, [pmc, #AT91_PMC_SCDR]
  61
  62         dsb
  63
  64         wfi             @ Wait For Interrupt
  65 #else
  66         mcr     p15, 0, tmp1, c7, c0, 4
  67 #endif
  68
  69         .endm
  70
  71         .text
  72
  73         .arm
  74
  75 /*
  76  * void at91_suspend_sram_fn(struct at91_pm_data*)
  77  * @input param:
  78  *      @r0: base address of struct at91_pm_data
  79  */
  80 /* at91_pm_suspend_in_sram must be 8-byte aligned per the requirements of fncpy() */
  81         .align 3
  82 ENTRY(at91_pm_suspend_in_sram)
  83         /* Save registers on stack */
  84         stmfd   sp!, {r4 - r12, lr}
  85
  86         /* Drain write buffer */
  87         mov     tmp1, #0
  88         mcr     p15, 0, tmp1, c7, c10, 4
  89
  90         ldr     tmp1, [r0, #PM_DATA_PMC]
  91         str     tmp1, .pmc_base
  92         ldr     tmp1, [r0, #PM_DATA_RAMC0]
  93         str     tmp1, .sramc_base
  94         ldr     tmp1, [r0, #PM_DATA_RAMC1]
  95         str     tmp1, .sramc1_base
  96         ldr     tmp1, [r0, #PM_DATA_MEMCTRL]
  97         str     tmp1, .memtype
  98         ldr     tmp1, [r0, #PM_DATA_MODE]
  99         str     tmp1, .pm_mode
 100         /* Both ldrne below are here to preload their address in the TLB */
 101         ldr     tmp1, [r0, #PM_DATA_SHDWC]
 102         str     tmp1, .shdwc
 103         cmp     tmp1, #0
 104         ldrne   tmp2, [tmp1, #0]
 105         ldr     tmp1, [r0, #PM_DATA_SFRBU]
 106         str     tmp1, .sfr
 107         cmp     tmp1, #0
 108         ldrne   tmp2, [tmp1, #0x10]
 109
 110         /* Active the self-refresh mode */
 111         mov     r0, #SRAMC_SELF_FRESH_ACTIVE
 112         bl      at91_sramc_self_refresh
 113
 114         ldr     r0, .pm_mode
 115         cmp     r0, #AT91_PM_SLOW_CLOCK
 116         beq     slow_clock
 117         cmp     r0, #AT91_PM_BACKUP
 118         beq     backup_mode
 119
 120         /* Wait for interrupt */
 121         ldr     pmc, .pmc_base
 122         at91_cpu_idle
 123         b       exit_suspend
 124
 125 slow_clock:
 126         bl      at91_slowck_mode
 127         b       exit_suspend
 128 backup_mode:
 129         bl      at91_backup_mode
 130         b       exit_suspend
 131
 132 exit_suspend:
 133         /* Exit the self-refresh mode */
 134         mov     r0, #SRAMC_SELF_FRESH_EXIT
 135         bl      at91_sramc_self_refresh
 136
 137         /* Restore registers, and return */
 138         ldmfd   sp!, {r4 - r12, pc}
 139 ENDPROC(at91_pm_suspend_in_sram)
 140
 141 ENTRY(at91_backup_mode)
 142         /*BUMEN*/
 143         ldr     r0, .sfr
 144         mov     tmp1, #0x1
 145         str     tmp1, [r0, #0x10]
 146
 147         /* Shutdown */
 148         ldr     r0, .shdwc
 149         mov     tmp1, #0xA5000000
 150         add     tmp1, tmp1, #0x1
 151         str     tmp1, [r0, #0]
 152 ENDPROC(at91_backup_mode)
 153
 154 ENTRY(at91_slowck_mode)
 155         ldr     pmc, .pmc_base
 156
 157         /* Save Master clock setting */
 158         ldr     tmp1, [pmc, #AT91_PMC_MCKR]
 159         str     tmp1, .saved_mckr
 160
 161         /*
 162          * Set the Master clock source to slow clock
 163          */
 164         bic     tmp1, tmp1, #AT91_PMC_CSS
 165         str     tmp1, [pmc, #AT91_PMC_MCKR]
 166
 167         wait_mckrdy
 168
 169         /* Save PLLA setting and disable it */
 170         ldr     tmp1, [pmc, #AT91_CKGR_PLLAR]
 171         str     tmp1, .saved_pllar
 172
 173         mov     tmp1, #AT91_PMC_PLLCOUNT
 174         orr     tmp1, tmp1, #(1 << 29)          /* bit 29 always set */
 175         str     tmp1, [pmc, #AT91_CKGR_PLLAR]
 176
 177         /* Turn off the main oscillator */
 178         ldr     tmp1, [pmc, #AT91_CKGR_MOR]
 179         bic     tmp1, tmp1, #AT91_PMC_MOSCEN
 180         orr     tmp1, tmp1, #AT91_PMC_KEY
 181         str     tmp1, [pmc, #AT91_CKGR_MOR]
 182
 183         /* Wait for interrupt */
 184         at91_cpu_idle
 185
 186         /* Turn on the main oscillator */
 187         ldr     tmp1, [pmc, #AT91_CKGR_MOR]
 188         orr     tmp1, tmp1, #AT91_PMC_MOSCEN
 189         orr     tmp1, tmp1, #AT91_PMC_KEY
 190         str     tmp1, [pmc, #AT91_CKGR_MOR]
 191
 192         wait_moscrdy
 193
 194         /* Restore PLLA setting */
 195         ldr     tmp1, .saved_pllar
 196         str     tmp1, [pmc, #AT91_CKGR_PLLAR]
 197
 198         tst     tmp1, #(AT91_PMC_MUL &  0xff0000)
 199         bne     3f
 200         tst     tmp1, #(AT91_PMC_MUL & ~0xff0000)
 201         beq     4f
 202 3:
 203         wait_pllalock
 204 4:
 205
 206         /*
 207          * Restore master clock setting
 208          */
 209         ldr     tmp1, .saved_mckr
 210         str     tmp1, [pmc, #AT91_PMC_MCKR]
 211
 212         wait_mckrdy
 213
 214         mov     pc, lr
 215 ENDPROC(at91_slowck_mode)
 216
 217 /*
 218  * void at91_sramc_self_refresh(unsigned int is_active)
 219  *
 220  * @input param:
 221  *      @r0: 1 - active self-refresh mode
 222  *           0 - exit self-refresh mode
 223  * register usage:
 224  *      @r1: memory type
 225  *      @r2: base address of the sram controller
 226  */
 227
 228 ENTRY(at91_sramc_self_refresh)
 229         ldr     r1, .memtype
 230         ldr     r2, .sramc_base
 231
 232         cmp     r1, #AT91_MEMCTRL_MC
 233         bne     ddrc_sf
 234
 235         /*
 236          * at91rm9200 Memory controller
 237          */
 238
 239          /*
 240           * For exiting the self-refresh mode, do nothing,
 241           * automatically exit the self-refresh mode.
 242           */
 243         tst     r0, #SRAMC_SELF_FRESH_ACTIVE
 244         beq     exit_sramc_sf
 245
 246         /* Active SDRAM self-refresh mode */
 247         mov     r3, #1
 248         str     r3, [r2, #AT91_MC_SDRAMC_SRR]
 249         b       exit_sramc_sf
 250
 251 ddrc_sf:
 252         cmp     r1, #AT91_MEMCTRL_DDRSDR
 253         bne     sdramc_sf
 254
 255         /*
 256          * DDR Memory controller
 257          */
 258         tst     r0, #SRAMC_SELF_FRESH_ACTIVE
 259         beq     ddrc_exit_sf
 260
 261         /* LPDDR1 --> force DDR2 mode during self-refresh */
 262         ldr     r3, [r2, #AT91_DDRSDRC_MDR]
 263         str     r3, .saved_sam9_mdr
 264         bic     r3, r3, #~AT91_DDRSDRC_MD
 265         cmp     r3, #AT91_DDRSDRC_MD_LOW_POWER_DDR
 266         ldreq   r3, [r2, #AT91_DDRSDRC_MDR]
 267         biceq   r3, r3, #AT91_DDRSDRC_MD
 268         orreq   r3, r3, #AT91_DDRSDRC_MD_DDR2
 269         streq   r3, [r2, #AT91_DDRSDRC_MDR]
 270
 271         /* Active DDRC self-refresh mode */
 272         ldr     r3, [r2, #AT91_DDRSDRC_LPR]
 273         str     r3, .saved_sam9_lpr
 274         bic     r3, r3, #AT91_DDRSDRC_LPCB
 275         orr     r3, r3, #AT91_DDRSDRC_LPCB_SELF_REFRESH
 276         str     r3, [r2, #AT91_DDRSDRC_LPR]
 277
 278         /* If using the 2nd ddr controller */
 279         ldr     r2, .sramc1_base
 280         cmp     r2, #0
 281         beq     no_2nd_ddrc
 282
 283         ldr     r3, [r2, #AT91_DDRSDRC_MDR]
 284         str     r3, .saved_sam9_mdr1
 285         bic     r3, r3, #~AT91_DDRSDRC_MD
 286         cmp     r3, #AT91_DDRSDRC_MD_LOW_POWER_DDR
 287         ldreq   r3, [r2, #AT91_DDRSDRC_MDR]
 288         biceq   r3, r3, #AT91_DDRSDRC_MD
 289         orreq   r3, r3, #AT91_DDRSDRC_MD_DDR2
 290         streq   r3, [r2, #AT91_DDRSDRC_MDR]
 291
 292         /* Active DDRC self-refresh mode */
 293         ldr     r3, [r2, #AT91_DDRSDRC_LPR]
 294         str     r3, .saved_sam9_lpr1
 295         bic     r3, r3, #AT91_DDRSDRC_LPCB
 296         orr     r3, r3, #AT91_DDRSDRC_LPCB_SELF_REFRESH
 297         str     r3, [r2, #AT91_DDRSDRC_LPR]
 298
 299 no_2nd_ddrc:
 300         b       exit_sramc_sf
 301
 302 ddrc_exit_sf:
 303         /* Restore MDR in case of LPDDR1 */
 304         ldr     r3, .saved_sam9_mdr
 305         str     r3, [r2, #AT91_DDRSDRC_MDR]
 306         /* Restore LPR on AT91 with DDRAM */
 307         ldr     r3, .saved_sam9_lpr
 308         str     r3, [r2, #AT91_DDRSDRC_LPR]
 309
 310         /* If using the 2nd ddr controller */
 311         ldr     r2, .sramc1_base
 312         cmp     r2, #0
 313         ldrne   r3, .saved_sam9_mdr1
 314         strne   r3, [r2, #AT91_DDRSDRC_MDR]
 315         ldrne   r3, .saved_sam9_lpr1
 316         strne   r3, [r2, #AT91_DDRSDRC_LPR]
 317
 318         b       exit_sramc_sf
 319
 320         /*
 321          * SDRAMC Memory controller
 322          */
 323 sdramc_sf:
 324         tst     r0, #SRAMC_SELF_FRESH_ACTIVE
 325         beq     sdramc_exit_sf
 326
 327         /* Active SDRAMC self-refresh mode */
 328         ldr     r3, [r2, #AT91_SDRAMC_LPR]
 329         str     r3, .saved_sam9_lpr
 330         bic     r3, r3, #AT91_SDRAMC_LPCB
 331         orr     r3, r3, #AT91_SDRAMC_LPCB_SELF_REFRESH
 332         str     r3, [r2, #AT91_SDRAMC_LPR]
 333
 334 sdramc_exit_sf:
 335         ldr     r3, .saved_sam9_lpr
 336         str     r3, [r2, #AT91_SDRAMC_LPR]
 337
 338 exit_sramc_sf:
 339         mov     pc, lr
 340 ENDPROC(at91_sramc_self_refresh)
 341
 342 .pmc_base:
 343         .word 0
 344 .sramc_base:
 345         .word 0
 346 .sramc1_base:
 347         .word 0
 348 .shdwc:
 349         .word 0
 350 .sfr:
 351         .word 0
 352 .memtype:
 353         .word 0
 354 .pm_mode:
 355         .word 0
 356 .saved_mckr:
 357         .word 0
 358 .saved_pllar:
 359         .word 0
 360 .saved_sam9_lpr:
 361         .word 0
 362 .saved_sam9_lpr1:
 363         .word 0
 364 .saved_sam9_mdr:
 365         .word 0
 366 .saved_sam9_mdr1:
 367         .word 0
 368
 369 ENTRY(at91_pm_suspend_in_sram_sz)
 370         .word .-at91_pm_suspend_in_sram