xref: /openbmc/linux/arch/arm/mach-omap2/sram242x.S (revision a2818ee4) 
1/*
2 * linux/arch/arm/mach-omap2/sram242x.S
3 *
4 * Omap2 specific functions that need to be run in internal SRAM
5 *
6 * (C) Copyright 2004
7 * Texas Instruments, <www.ti.com>
8 * Richard Woodruff <r-woodruff2@ti.com>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of
13 * the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR /PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
23 * MA 02111-1307 USA
24 *
25 * Richard Woodruff notes that any changes to this code must be carefully
26 * audited and tested to ensure that they don't cause a TLB miss while
27 * the SDRAM is inaccessible.  Such a situation will crash the system
28 * since it will cause the ARM MMU to attempt to walk the page tables.
29 * These crashes may be intermittent.
30 */
31#include <linux/linkage.h>
32
33#include <asm/assembler.h>
34
35#include "soc.h"
36#include "iomap.h"
37#include "prm2xxx.h"
38#include "cm2xxx.h"
39#include "sdrc.h"
40
41	.text
42
43	.align	3
44ENTRY(omap242x_sram_ddr_init)
45	stmfd	sp!, {r0 - r12, lr}	@ save registers on stack
46
47	mov	r12, r2			@ capture CS1 vs CS0
48	mov	r8, r3			@ capture force parameter
49
50	/* frequency shift down */
51	ldr	r2, omap242x_sdi_cm_clksel2_pll	@ get address of dpllout reg
52	mov	r3, #0x1		@ value for 1x operation
53	str	r3, [r2]		@ go to L1-freq operation
54
55	/* voltage shift down */
56	mov r9, #0x1			@ set up for L1 voltage call
57	bl voltage_shift		@ go drop voltage
58
59	/* dll lock mode */
60	ldr	r11, omap242x_sdi_sdrc_dlla_ctrl	@ addr of dlla ctrl
61	ldr	r10, [r11]		@ get current val
62	cmp	r12, #0x1		@ cs1 base (2422 es2.05/1)
63	addeq	r11, r11, #0x8		@ if cs1 base, move to DLLB
64	mvn	r9, #0x4		@ mask to get clear bit2
65	and	r10, r10, r9		@ clear bit2 for lock mode.
66	orr	r10, r10, #0x8		@ make sure DLL on (es2 bit pos)
67	orr	r10, r10, #0x2		@ 90 degree phase for all below 133MHz
68	str	r10, [r11]		@ commit to DLLA_CTRL
69	bl	i_dll_wait		@ wait for dll to lock
70
71	/* get dll value */
72	add	r11, r11, #0x4		@ get addr of status reg
73	ldr	r10, [r11]		@ get locked value
74
75	/* voltage shift up */
76	mov r9, #0x0			@ shift back to L0-voltage
77	bl voltage_shift		@ go raise voltage
78
79	/* frequency shift up */
80	mov	r3, #0x2		@ value for 2x operation
81	str	r3, [r2]		@ go to L0-freq operation
82
83	/* reset entry mode for dllctrl */
84	sub	r11, r11, #0x4		@ move from status to ctrl
85	cmp	r12, #0x1		@ normalize if cs1 based
86	subeq	r11, r11, #0x8		@ possibly back to DLLA
87	cmp	r8, #0x1		@ if forced unlock exit
88	orreq	r1, r1, #0x4		@ make sure exit with unlocked value
89	str	r1, [r11]		@ restore DLLA_CTRL high value
90	add	r11, r11, #0x8		@ move to DLLB_CTRL addr
91	str	r1, [r11]		@ set value DLLB_CTRL
92	bl	i_dll_wait		@ wait for possible lock
93
94	/* set up for return, DDR should be good */
95	str r10, [r0]			@ write dll_status and return counter
96	ldmfd	sp!, {r0 - r12, pc}	@ restore regs and return
97
98	/* ensure the DLL has relocked */
99i_dll_wait:
100	mov	r4, #0x800		@ delay DLL relock, min 0x400 L3 clocks
101i_dll_delay:
102	subs	r4, r4, #0x1
103	bne	i_dll_delay
104	ret	lr
105
106	/*
107	 * shift up or down voltage, use R9 as input to tell level.
108	 * wait for it to finish, use 32k sync counter, 1tick=31uS.
109	 */
110voltage_shift:
111	ldr	r4, omap242x_sdi_prcm_voltctrl	@ get addr of volt ctrl.
112	ldr	r5, [r4]		@ get value.
113	ldr	r6, prcm_mask_val	@ get value of mask
114	and	r5, r5, r6		@ apply mask to clear bits
115	orr	r5, r5, r9		@ bulld value for L0/L1-volt operation.
116	str	r5, [r4]		@ set up for change.
117	mov	r3, #0x4000		@ get val for force
118	orr	r5, r5, r3		@ build value for force
119	str	r5, [r4]		@ Force transition to L1
120
121	ldr	r3, omap242x_sdi_timer_32ksynct_cr	@ get addr of counter
122	ldr	r5, [r3]		@ get value
123	add	r5, r5, #0x3		@ give it at most 93uS
124volt_delay:
125	ldr	r7, [r3]		@ get timer value
126	cmp	r5, r7			@ time up?
127	bhi	volt_delay		@ not yet->branch
128	ret	lr			@ back to caller.
129
130omap242x_sdi_cm_clksel2_pll:
131	.word OMAP2420_CM_REGADDR(PLL_MOD, CM_CLKSEL2)
132omap242x_sdi_sdrc_dlla_ctrl:
133	.word OMAP242X_SDRC_REGADDR(SDRC_DLLA_CTRL)
134omap242x_sdi_prcm_voltctrl:
135	.word OMAP2420_PRCM_VOLTCTRL
136prcm_mask_val:
137	.word 0xFFFF3FFC
138omap242x_sdi_timer_32ksynct_cr:
139	.word OMAP2_L4_IO_ADDRESS(OMAP2420_32KSYNCT_BASE + 0x010)
140ENTRY(omap242x_sram_ddr_init_sz)
141	.word	. - omap242x_sram_ddr_init
142
143/*
144 * Reprograms memory timings.
145 * r0 = [PRCM_FULL | PRCM_HALF] r1 = SDRC_DLLA_CTRL value r2 = [DDR | SDR]
146 * PRCM_FULL = 2, PRCM_HALF = 1, DDR = 1, SDR = 0
147 */
148	.align	3
149ENTRY(omap242x_sram_reprogram_sdrc)
150	stmfd	sp!, {r0 - r10, lr}	@ save registers on stack
151	mov	r3, #0x0		@ clear for mrc call
152	mcr	p15, 0, r3, c7, c10, 4	@ memory barrier, finish ARM SDR/DDR
153	nop
154	nop
155	ldr	r6, omap242x_srs_sdrc_rfr_ctrl	@ get addr of refresh reg
156	ldr	r5, [r6]		@ get value
157	mov	r5, r5, lsr #8		@ isolate rfr field and drop burst
158
159	cmp	r0, #0x1		@ going to half speed?
160	movne	r9, #0x0		@ if up set flag up for pre up, hi volt
161
162	blne	voltage_shift_c		@ adjust voltage
163
164	cmp	r0, #0x1		@ going to half speed (post branch link)
165	moveq	r5, r5, lsr #1		@ divide by 2 if to half
166	movne	r5, r5, lsl #1		@ mult by 2 if to full
167	mov	r5, r5, lsl #8		@ put rfr field back into place
168	add	r5, r5, #0x1		@ turn on burst of 1
169	ldr	r4, omap242x_srs_cm_clksel2_pll	@ get address of out reg
170	ldr	r3, [r4]		@ get curr value
171	orr	r3, r3, #0x3
172	bic	r3, r3, #0x3		@ clear lower bits
173	orr	r3, r3, r0		@ new state value
174	str	r3, [r4]		@ set new state (pll/x, x=1 or 2)
175	nop
176	nop
177
178	moveq	r9, #0x1		@ if speed down, post down, drop volt
179	bleq	voltage_shift_c
180
181	mcr	p15, 0, r3, c7, c10, 4	@ memory barrier
182	str	r5, [r6]		@ set new RFR_1 value
183	add	r6, r6, #0x30		@ get RFR_2 addr
184	str	r5, [r6]		@ set RFR_2
185	nop
186	cmp	r2, #0x1		@ (SDR or DDR) do we need to adjust DLL
187	bne	freq_out		@ leave if SDR, no DLL function
188
189	/* With DDR, we need to take care of the DLL for the frequency change */
190	ldr	r2, omap242x_srs_sdrc_dlla_ctrl	@ addr of dlla ctrl
191	str	r1, [r2]		@ write out new SDRC_DLLA_CTRL
192	add	r2, r2, #0x8		@ addr to SDRC_DLLB_CTRL
193	str	r1, [r2]		@ commit to SDRC_DLLB_CTRL
194	mov	r1, #0x2000		@ wait DLL relock, min 0x400 L3 clocks
195dll_wait:
196	subs	r1, r1, #0x1
197	bne	dll_wait
198freq_out:
199	ldmfd	sp!, {r0 - r10, pc}	@ restore regs and return
200
201    /*
202     * shift up or down voltage, use R9 as input to tell level.
203     *	wait for it to finish, use 32k sync counter, 1tick=31uS.
204     */
205voltage_shift_c:
206	ldr	r10, omap242x_srs_prcm_voltctrl	@ get addr of volt ctrl
207	ldr	r8, [r10]		@ get value
208	ldr	r7, ddr_prcm_mask_val	@ get value of mask
209	and	r8, r8, r7		@ apply mask to clear bits
210	orr	r8, r8, r9		@ bulld value for L0/L1-volt operation.
211	str	r8, [r10]		@ set up for change.
212	mov	r7, #0x4000		@ get val for force
213	orr	r8, r8, r7		@ build value for force
214	str	r8, [r10]		@ Force transition to L1
215
216	ldr	r10, omap242x_srs_timer_32ksynct	@ get addr of counter
217	ldr	r8, [r10]		@ get value
218	add	r8, r8, #0x2		@ give it at most 62uS (min 31+)
219volt_delay_c:
220	ldr	r7, [r10]		@ get timer value
221	cmp	r8, r7			@ time up?
222	bhi	volt_delay_c		@ not yet->branch
223	ret	lr			@ back to caller
224
225omap242x_srs_cm_clksel2_pll:
226	.word OMAP2420_CM_REGADDR(PLL_MOD, CM_CLKSEL2)
227omap242x_srs_sdrc_dlla_ctrl:
228	.word OMAP242X_SDRC_REGADDR(SDRC_DLLA_CTRL)
229omap242x_srs_sdrc_rfr_ctrl:
230	.word OMAP242X_SDRC_REGADDR(SDRC_RFR_CTRL_0)
231omap242x_srs_prcm_voltctrl:
232	.word OMAP2420_PRCM_VOLTCTRL
233ddr_prcm_mask_val:
234	.word 0xFFFF3FFC
235omap242x_srs_timer_32ksynct:
236	.word OMAP2_L4_IO_ADDRESS(OMAP2420_32KSYNCT_BASE + 0x010)
237
238ENTRY(omap242x_sram_reprogram_sdrc_sz)
239	.word	. - omap242x_sram_reprogram_sdrc
240
241/*
242 * Set dividers and pll. Also recalculate DLL value for DDR and unlock mode.
243 */
244	.align	3
245ENTRY(omap242x_sram_set_prcm)
246	stmfd	sp!, {r0-r12, lr}	@ regs to stack
247	adr	r4, pbegin		@ addr of preload start
248	adr	r8, pend		@ addr of preload end
249	mcrr	p15, 1, r8, r4, c12	@ preload into icache
250pbegin:
251	/* move into fast relock bypass */
252	ldr	r8, omap242x_ssp_pll_ctl	@ get addr
253	ldr	r5, [r8]		@ get val
254	mvn	r6, #0x3		@ clear mask
255	and	r5, r5, r6		@ clear field
256	orr	r7, r5, #0x2		@ fast relock val
257	str	r7, [r8]		@ go to fast relock
258	ldr	r4, omap242x_ssp_pll_stat	@ addr of stat
259block:
260	/* wait for bypass */
261	ldr	r8, [r4]		@ stat value
262	and	r8, r8, #0x3		@ mask for stat
263	cmp	r8, #0x1		@ there yet
264	bne	block			@ loop if not
265
266	/* set new dpll dividers _after_ in bypass */
267	ldr	r4, omap242x_ssp_pll_div	@ get addr
268	str	r0, [r4]		@ set dpll ctrl val
269
270	ldr	r4, omap242x_ssp_set_config	@ get addr
271	mov	r8, #1			@ valid cfg msk
272	str	r8, [r4]		@ make dividers take
273
274	mov	r4, #100		@ dead spin a bit
275wait_a_bit:
276	subs	r4, r4, #1		@ dec loop
277	bne	wait_a_bit		@ delay done?
278
279	/* check if staying in bypass */
280	cmp	r2, #0x1		@ stay in bypass?
281	beq	pend			@ jump over dpll relock
282
283	/* relock DPLL with new vals */
284	ldr	r5, omap242x_ssp_pll_stat	@ get addr
285	ldr	r4, omap242x_ssp_pll_ctl	@ get addr
286	orr	r8, r7, #0x3		@ val for lock dpll
287	str	r8, [r4]		@ set val
288	mov	r0, #1000		@ dead spin a bit
289wait_more:
290	subs	r0, r0, #1		@ dec loop
291	bne	wait_more		@ delay done?
292wait_lock:
293	ldr	r8, [r5]		@ get lock val
294	and	r8, r8, #3		@ isolate field
295	cmp	r8, #2			@ locked?
296	bne	wait_lock		@ wait if not
297pend:
298	/* update memory timings & briefly lock dll */
299	ldr	r4, omap242x_ssp_sdrc_rfr	@ get addr
300	str	r1, [r4]		@ update refresh timing
301	ldr	r11, omap242x_ssp_dlla_ctrl	@ get addr of DLLA ctrl
302	ldr	r10, [r11]		@ get current val
303	mvn	r9, #0x4		@ mask to get clear bit2
304	and	r10, r10, r9		@ clear bit2 for lock mode
305	orr	r10, r10, #0x8		@ make sure DLL on (es2 bit pos)
306	str	r10, [r11]		@ commit to DLLA_CTRL
307	add	r11, r11, #0x8		@ move to dllb
308	str	r10, [r11]		@ hit DLLB also
309
310	mov	r4, #0x800		@ relock time (min 0x400 L3 clocks)
311wait_dll_lock:
312	subs	r4, r4, #0x1
313	bne	wait_dll_lock
314	nop
315	ldmfd	sp!, {r0-r12, pc}	@ restore regs and return
316
317omap242x_ssp_set_config:
318	.word OMAP2420_PRCM_CLKCFG_CTRL
319omap242x_ssp_pll_ctl:
320	.word OMAP2420_CM_REGADDR(PLL_MOD, CM_CLKEN)
321omap242x_ssp_pll_stat:
322	.word OMAP2420_CM_REGADDR(PLL_MOD, CM_IDLEST)
323omap242x_ssp_pll_div:
324	.word OMAP2420_CM_REGADDR(PLL_MOD, CM_CLKSEL1)
325omap242x_ssp_sdrc_rfr:
326	.word OMAP242X_SDRC_REGADDR(SDRC_RFR_CTRL_0)
327omap242x_ssp_dlla_ctrl:
328	.word OMAP242X_SDRC_REGADDR(SDRC_DLLA_CTRL)
329
330ENTRY(omap242x_sram_set_prcm_sz)
331	.word	. - omap242x_sram_set_prcm
332