1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * linux/arch/arm/mach-omap2/sram242x.S 4 * 5 * Omap2 specific functions that need to be run in internal SRAM 6 * 7 * (C) Copyright 2004 8 * Texas Instruments, <www.ti.com> 9 * Richard Woodruff <r-woodruff2@ti.com> 10 * 11 * Richard Woodruff notes that any changes to this code must be carefully 12 * audited and tested to ensure that they don't cause a TLB miss while 13 * the SDRAM is inaccessible. Such a situation will crash the system 14 * since it will cause the ARM MMU to attempt to walk the page tables. 15 * These crashes may be intermittent. 16 */ 17 #include <linux/linkage.h> 18 19 #include <asm/assembler.h> 20 21 #include "soc.h" 22 #include "iomap.h" 23 #include "prm2xxx.h" 24 #include "cm2xxx.h" 25 #include "sdrc.h" 26 27 .text 28 29 .align 3 30 ENTRY(omap242x_sram_ddr_init) 31 stmfd sp!, {r0 - r12, lr} @ save registers on stack 32 33 mov r12, r2 @ capture CS1 vs CS0 34 mov r8, r3 @ capture force parameter 35 36 /* frequency shift down */ 37 ldr r2, omap242x_sdi_cm_clksel2_pll @ get address of dpllout reg 38 mov r3, #0x1 @ value for 1x operation 39 str r3, [r2] @ go to L1-freq operation 40 41 /* voltage shift down */ 42 mov r9, #0x1 @ set up for L1 voltage call 43 bl voltage_shift @ go drop voltage 44 45 /* dll lock mode */ 46 ldr r11, omap242x_sdi_sdrc_dlla_ctrl @ addr of dlla ctrl 47 ldr r10, [r11] @ get current val 48 cmp r12, #0x1 @ cs1 base (2422 es2.05/1) 49 addeq r11, r11, #0x8 @ if cs1 base, move to DLLB 50 mvn r9, #0x4 @ mask to get clear bit2 51 and r10, r10, r9 @ clear bit2 for lock mode. 52 orr r10, r10, #0x8 @ make sure DLL on (es2 bit pos) 53 orr r10, r10, #0x2 @ 90 degree phase for all below 133MHz 54 str r10, [r11] @ commit to DLLA_CTRL 55 bl i_dll_wait @ wait for dll to lock 56 57 /* get dll value */ 58 add r11, r11, #0x4 @ get addr of status reg 59 ldr r10, [r11] @ get locked value 60 61 /* voltage shift up */ 62 mov r9, #0x0 @ shift back to L0-voltage 63 bl voltage_shift @ go raise voltage 64 65 /* frequency shift up */ 66 mov r3, #0x2 @ value for 2x operation 67 str r3, [r2] @ go to L0-freq operation 68 69 /* reset entry mode for dllctrl */ 70 sub r11, r11, #0x4 @ move from status to ctrl 71 cmp r12, #0x1 @ normalize if cs1 based 72 subeq r11, r11, #0x8 @ possibly back to DLLA 73 cmp r8, #0x1 @ if forced unlock exit 74 orreq r1, r1, #0x4 @ make sure exit with unlocked value 75 str r1, [r11] @ restore DLLA_CTRL high value 76 add r11, r11, #0x8 @ move to DLLB_CTRL addr 77 str r1, [r11] @ set value DLLB_CTRL 78 bl i_dll_wait @ wait for possible lock 79 80 /* set up for return, DDR should be good */ 81 str r10, [r0] @ write dll_status and return counter 82 ldmfd sp!, {r0 - r12, pc} @ restore regs and return 83 84 /* ensure the DLL has relocked */ 85 i_dll_wait: 86 mov r4, #0x800 @ delay DLL relock, min 0x400 L3 clocks 87 i_dll_delay: 88 subs r4, r4, #0x1 89 bne i_dll_delay 90 ret lr 91 92 /* 93 * shift up or down voltage, use R9 as input to tell level. 94 * wait for it to finish, use 32k sync counter, 1tick=31uS. 95 */ 96 voltage_shift: 97 ldr r4, omap242x_sdi_prcm_voltctrl @ get addr of volt ctrl. 98 ldr r5, [r4] @ get value. 99 ldr r6, prcm_mask_val @ get value of mask 100 and r5, r5, r6 @ apply mask to clear bits 101 orr r5, r5, r9 @ bulld value for L0/L1-volt operation. 102 str r5, [r4] @ set up for change. 103 mov r3, #0x4000 @ get val for force 104 orr r5, r5, r3 @ build value for force 105 str r5, [r4] @ Force transition to L1 106 107 ldr r3, omap242x_sdi_timer_32ksynct_cr @ get addr of counter 108 ldr r5, [r3] @ get value 109 add r5, r5, #0x3 @ give it at most 93uS 110 volt_delay: 111 ldr r7, [r3] @ get timer value 112 cmp r5, r7 @ time up? 113 bhi volt_delay @ not yet->branch 114 ret lr @ back to caller. 115 116 omap242x_sdi_cm_clksel2_pll: 117 .word OMAP2420_CM_REGADDR(PLL_MOD, CM_CLKSEL2) 118 omap242x_sdi_sdrc_dlla_ctrl: 119 .word OMAP242X_SDRC_REGADDR(SDRC_DLLA_CTRL) 120 omap242x_sdi_prcm_voltctrl: 121 .word OMAP2420_PRCM_VOLTCTRL 122 prcm_mask_val: 123 .word 0xFFFF3FFC 124 omap242x_sdi_timer_32ksynct_cr: 125 .word OMAP2_L4_IO_ADDRESS(OMAP2420_32KSYNCT_BASE + 0x010) 126 ENTRY(omap242x_sram_ddr_init_sz) 127 .word . - omap242x_sram_ddr_init 128 129 /* 130 * Reprograms memory timings. 131 * r0 = [PRCM_FULL | PRCM_HALF] r1 = SDRC_DLLA_CTRL value r2 = [DDR | SDR] 132 * PRCM_FULL = 2, PRCM_HALF = 1, DDR = 1, SDR = 0 133 */ 134 .align 3 135 ENTRY(omap242x_sram_reprogram_sdrc) 136 stmfd sp!, {r0 - r10, lr} @ save registers on stack 137 mov r3, #0x0 @ clear for mrc call 138 mcr p15, 0, r3, c7, c10, 4 @ memory barrier, finish ARM SDR/DDR 139 nop 140 nop 141 ldr r6, omap242x_srs_sdrc_rfr_ctrl @ get addr of refresh reg 142 ldr r5, [r6] @ get value 143 mov r5, r5, lsr #8 @ isolate rfr field and drop burst 144 145 cmp r0, #0x1 @ going to half speed? 146 movne r9, #0x0 @ if up set flag up for pre up, hi volt 147 148 blne voltage_shift_c @ adjust voltage 149 150 cmp r0, #0x1 @ going to half speed (post branch link) 151 moveq r5, r5, lsr #1 @ divide by 2 if to half 152 movne r5, r5, lsl #1 @ mult by 2 if to full 153 mov r5, r5, lsl #8 @ put rfr field back into place 154 add r5, r5, #0x1 @ turn on burst of 1 155 ldr r4, omap242x_srs_cm_clksel2_pll @ get address of out reg 156 ldr r3, [r4] @ get curr value 157 orr r3, r3, #0x3 158 bic r3, r3, #0x3 @ clear lower bits 159 orr r3, r3, r0 @ new state value 160 str r3, [r4] @ set new state (pll/x, x=1 or 2) 161 nop 162 nop 163 164 moveq r9, #0x1 @ if speed down, post down, drop volt 165 bleq voltage_shift_c 166 167 mcr p15, 0, r3, c7, c10, 4 @ memory barrier 168 str r5, [r6] @ set new RFR_1 value 169 add r6, r6, #0x30 @ get RFR_2 addr 170 str r5, [r6] @ set RFR_2 171 nop 172 cmp r2, #0x1 @ (SDR or DDR) do we need to adjust DLL 173 bne freq_out @ leave if SDR, no DLL function 174 175 /* With DDR, we need to take care of the DLL for the frequency change */ 176 ldr r2, omap242x_srs_sdrc_dlla_ctrl @ addr of dlla ctrl 177 str r1, [r2] @ write out new SDRC_DLLA_CTRL 178 add r2, r2, #0x8 @ addr to SDRC_DLLB_CTRL 179 str r1, [r2] @ commit to SDRC_DLLB_CTRL 180 mov r1, #0x2000 @ wait DLL relock, min 0x400 L3 clocks 181 dll_wait: 182 subs r1, r1, #0x1 183 bne dll_wait 184 freq_out: 185 ldmfd sp!, {r0 - r10, pc} @ restore regs and return 186 187 /* 188 * shift up or down voltage, use R9 as input to tell level. 189 * wait for it to finish, use 32k sync counter, 1tick=31uS. 190 */ 191 voltage_shift_c: 192 ldr r10, omap242x_srs_prcm_voltctrl @ get addr of volt ctrl 193 ldr r8, [r10] @ get value 194 ldr r7, ddr_prcm_mask_val @ get value of mask 195 and r8, r8, r7 @ apply mask to clear bits 196 orr r8, r8, r9 @ bulld value for L0/L1-volt operation. 197 str r8, [r10] @ set up for change. 198 mov r7, #0x4000 @ get val for force 199 orr r8, r8, r7 @ build value for force 200 str r8, [r10] @ Force transition to L1 201 202 ldr r10, omap242x_srs_timer_32ksynct @ get addr of counter 203 ldr r8, [r10] @ get value 204 add r8, r8, #0x2 @ give it at most 62uS (min 31+) 205 volt_delay_c: 206 ldr r7, [r10] @ get timer value 207 cmp r8, r7 @ time up? 208 bhi volt_delay_c @ not yet->branch 209 ret lr @ back to caller 210 211 omap242x_srs_cm_clksel2_pll: 212 .word OMAP2420_CM_REGADDR(PLL_MOD, CM_CLKSEL2) 213 omap242x_srs_sdrc_dlla_ctrl: 214 .word OMAP242X_SDRC_REGADDR(SDRC_DLLA_CTRL) 215 omap242x_srs_sdrc_rfr_ctrl: 216 .word OMAP242X_SDRC_REGADDR(SDRC_RFR_CTRL_0) 217 omap242x_srs_prcm_voltctrl: 218 .word OMAP2420_PRCM_VOLTCTRL 219 ddr_prcm_mask_val: 220 .word 0xFFFF3FFC 221 omap242x_srs_timer_32ksynct: 222 .word OMAP2_L4_IO_ADDRESS(OMAP2420_32KSYNCT_BASE + 0x010) 223 224 ENTRY(omap242x_sram_reprogram_sdrc_sz) 225 .word . - omap242x_sram_reprogram_sdrc 226 227 /* 228 * Set dividers and pll. Also recalculate DLL value for DDR and unlock mode. 229 */ 230 .align 3 231 ENTRY(omap242x_sram_set_prcm) 232 stmfd sp!, {r0-r12, lr} @ regs to stack 233 adr r4, pbegin @ addr of preload start 234 adr r8, pend @ addr of preload end 235 mcrr p15, 1, r8, r4, c12 @ preload into icache 236 pbegin: 237 /* move into fast relock bypass */ 238 ldr r8, omap242x_ssp_pll_ctl @ get addr 239 ldr r5, [r8] @ get val 240 mvn r6, #0x3 @ clear mask 241 and r5, r5, r6 @ clear field 242 orr r7, r5, #0x2 @ fast relock val 243 str r7, [r8] @ go to fast relock 244 ldr r4, omap242x_ssp_pll_stat @ addr of stat 245 block: 246 /* wait for bypass */ 247 ldr r8, [r4] @ stat value 248 and r8, r8, #0x3 @ mask for stat 249 cmp r8, #0x1 @ there yet 250 bne block @ loop if not 251 252 /* set new dpll dividers _after_ in bypass */ 253 ldr r4, omap242x_ssp_pll_div @ get addr 254 str r0, [r4] @ set dpll ctrl val 255 256 ldr r4, omap242x_ssp_set_config @ get addr 257 mov r8, #1 @ valid cfg msk 258 str r8, [r4] @ make dividers take 259 260 mov r4, #100 @ dead spin a bit 261 wait_a_bit: 262 subs r4, r4, #1 @ dec loop 263 bne wait_a_bit @ delay done? 264 265 /* check if staying in bypass */ 266 cmp r2, #0x1 @ stay in bypass? 267 beq pend @ jump over dpll relock 268 269 /* relock DPLL with new vals */ 270 ldr r5, omap242x_ssp_pll_stat @ get addr 271 ldr r4, omap242x_ssp_pll_ctl @ get addr 272 orr r8, r7, #0x3 @ val for lock dpll 273 str r8, [r4] @ set val 274 mov r0, #1000 @ dead spin a bit 275 wait_more: 276 subs r0, r0, #1 @ dec loop 277 bne wait_more @ delay done? 278 wait_lock: 279 ldr r8, [r5] @ get lock val 280 and r8, r8, #3 @ isolate field 281 cmp r8, #2 @ locked? 282 bne wait_lock @ wait if not 283 pend: 284 /* update memory timings & briefly lock dll */ 285 ldr r4, omap242x_ssp_sdrc_rfr @ get addr 286 str r1, [r4] @ update refresh timing 287 ldr r11, omap242x_ssp_dlla_ctrl @ get addr of DLLA ctrl 288 ldr r10, [r11] @ get current val 289 mvn r9, #0x4 @ mask to get clear bit2 290 and r10, r10, r9 @ clear bit2 for lock mode 291 orr r10, r10, #0x8 @ make sure DLL on (es2 bit pos) 292 str r10, [r11] @ commit to DLLA_CTRL 293 add r11, r11, #0x8 @ move to dllb 294 str r10, [r11] @ hit DLLB also 295 296 mov r4, #0x800 @ relock time (min 0x400 L3 clocks) 297 wait_dll_lock: 298 subs r4, r4, #0x1 299 bne wait_dll_lock 300 nop 301 ldmfd sp!, {r0-r12, pc} @ restore regs and return 302 303 omap242x_ssp_set_config: 304 .word OMAP2420_PRCM_CLKCFG_CTRL 305 omap242x_ssp_pll_ctl: 306 .word OMAP2420_CM_REGADDR(PLL_MOD, CM_CLKEN) 307 omap242x_ssp_pll_stat: 308 .word OMAP2420_CM_REGADDR(PLL_MOD, CM_IDLEST) 309 omap242x_ssp_pll_div: 310 .word OMAP2420_CM_REGADDR(PLL_MOD, CM_CLKSEL1) 311 omap242x_ssp_sdrc_rfr: 312 .word OMAP242X_SDRC_REGADDR(SDRC_RFR_CTRL_0) 313 omap242x_ssp_dlla_ctrl: 314 .word OMAP242X_SDRC_REGADDR(SDRC_DLLA_CTRL) 315 316 ENTRY(omap242x_sram_set_prcm_sz) 317 .word . - omap242x_sram_set_prcm 318