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
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