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1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/mach-sa1100/cpu-sa1110.c | |
3 | * | |
4 | * Copyright (C) 2001 Russell King | |
5 | * | |
6 | * $Id: cpu-sa1110.c,v 1.9 2002/07/06 16:53:18 rmk Exp $ | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | * | |
12 | * Note: there are two erratas that apply to the SA1110 here: | |
13 | * 7 - SDRAM auto-power-up failure (rev A0) | |
14 | * 13 - Corruption of internal register reads/writes following | |
15 | * SDRAM reads (rev A0, B0, B1) | |
16 | * | |
17 | * We ignore rev. A0 and B0 devices; I don't think they're worth supporting. | |
ba532011 RK |
18 | * |
19 | * The SDRAM type can be passed on the command line as cpu_sa1110.sdram=type | |
1da177e4 | 20 | */ |
ba532011 | 21 | #include <linux/moduleparam.h> |
1da177e4 LT |
22 | #include <linux/types.h> |
23 | #include <linux/kernel.h> | |
24 | #include <linux/sched.h> | |
25 | #include <linux/cpufreq.h> | |
26 | #include <linux/delay.h> | |
27 | #include <linux/init.h> | |
28 | ||
29 | #include <asm/hardware.h> | |
30 | #include <asm/mach-types.h> | |
31 | #include <asm/io.h> | |
32 | #include <asm/system.h> | |
33 | ||
34 | #include "generic.h" | |
35 | ||
36 | #undef DEBUG | |
37 | ||
38 | static struct cpufreq_driver sa1110_driver; | |
39 | ||
40 | struct sdram_params { | |
ba532011 | 41 | const char name[16]; |
1da177e4 LT |
42 | u_char rows; /* bits */ |
43 | u_char cas_latency; /* cycles */ | |
44 | u_char tck; /* clock cycle time (ns) */ | |
45 | u_char trcd; /* activate to r/w (ns) */ | |
46 | u_char trp; /* precharge to activate (ns) */ | |
47 | u_char twr; /* write recovery time (ns) */ | |
48 | u_short refresh; /* refresh time for array (us) */ | |
49 | }; | |
50 | ||
51 | struct sdram_info { | |
52 | u_int mdcnfg; | |
53 | u_int mdrefr; | |
54 | u_int mdcas[3]; | |
55 | }; | |
56 | ||
ba532011 RK |
57 | static struct sdram_params sdram_tbl[] __initdata = { |
58 | { /* Toshiba TC59SM716 CL2 */ | |
59 | .name = "TC59SM716-CL2", | |
60 | .rows = 12, | |
61 | .tck = 10, | |
62 | .trcd = 20, | |
63 | .trp = 20, | |
64 | .twr = 10, | |
65 | .refresh = 64000, | |
66 | .cas_latency = 2, | |
67 | }, { /* Toshiba TC59SM716 CL3 */ | |
68 | .name = "TC59SM716-CL3", | |
69 | .rows = 12, | |
70 | .tck = 8, | |
71 | .trcd = 20, | |
72 | .trp = 20, | |
73 | .twr = 8, | |
74 | .refresh = 64000, | |
75 | .cas_latency = 3, | |
76 | }, { /* Samsung K4S641632D TC75 */ | |
77 | .name = "K4S641632D", | |
78 | .rows = 14, | |
79 | .tck = 9, | |
80 | .trcd = 27, | |
81 | .trp = 20, | |
82 | .twr = 9, | |
83 | .refresh = 64000, | |
84 | .cas_latency = 3, | |
48e3becb | 85 | }, { /* Samsung K4S281632B-1H */ |
9f0f9313 | 86 | .name = "K4S281632B-1H", |
48e3becb KE |
87 | .rows = 12, |
88 | .tck = 10, | |
89 | .trp = 20, | |
90 | .twr = 10, | |
91 | .refresh = 64000, | |
92 | .cas_latency = 3, | |
ba532011 RK |
93 | }, { /* Samsung KM416S4030CT */ |
94 | .name = "KM416S4030CT", | |
95 | .rows = 13, | |
96 | .tck = 8, | |
97 | .trcd = 24, /* 3 CLKs */ | |
98 | .trp = 24, /* 3 CLKs */ | |
99 | .twr = 16, /* Trdl: 2 CLKs */ | |
100 | .refresh = 64000, | |
101 | .cas_latency = 3, | |
102 | }, { /* Winbond W982516AH75L CL3 */ | |
103 | .name = "W982516AH75L", | |
104 | .rows = 16, | |
105 | .tck = 8, | |
106 | .trcd = 20, | |
107 | .trp = 20, | |
108 | .twr = 8, | |
109 | .refresh = 64000, | |
110 | .cas_latency = 3, | |
111 | }, | |
1da177e4 LT |
112 | }; |
113 | ||
114 | static struct sdram_params sdram_params; | |
115 | ||
116 | /* | |
117 | * Given a period in ns and frequency in khz, calculate the number of | |
118 | * cycles of frequency in period. Note that we round up to the next | |
119 | * cycle, even if we are only slightly over. | |
120 | */ | |
121 | static inline u_int ns_to_cycles(u_int ns, u_int khz) | |
122 | { | |
123 | return (ns * khz + 999999) / 1000000; | |
124 | } | |
125 | ||
126 | /* | |
127 | * Create the MDCAS register bit pattern. | |
128 | */ | |
129 | static inline void set_mdcas(u_int *mdcas, int delayed, u_int rcd) | |
130 | { | |
131 | u_int shift; | |
132 | ||
133 | rcd = 2 * rcd - 1; | |
134 | shift = delayed + 1 + rcd; | |
135 | ||
136 | mdcas[0] = (1 << rcd) - 1; | |
137 | mdcas[0] |= 0x55555555 << shift; | |
138 | mdcas[1] = mdcas[2] = 0x55555555 << (shift & 1); | |
139 | } | |
140 | ||
141 | static void | |
142 | sdram_calculate_timing(struct sdram_info *sd, u_int cpu_khz, | |
143 | struct sdram_params *sdram) | |
144 | { | |
145 | u_int mem_khz, sd_khz, trp, twr; | |
146 | ||
147 | mem_khz = cpu_khz / 2; | |
148 | sd_khz = mem_khz; | |
149 | ||
150 | /* | |
151 | * If SDCLK would invalidate the SDRAM timings, | |
152 | * run SDCLK at half speed. | |
153 | * | |
154 | * CPU steppings prior to B2 must either run the memory at | |
155 | * half speed or use delayed read latching (errata 13). | |
156 | */ | |
157 | if ((ns_to_cycles(sdram->tck, sd_khz) > 1) || | |
158 | (CPU_REVISION < CPU_SA1110_B2 && sd_khz < 62000)) | |
159 | sd_khz /= 2; | |
160 | ||
161 | sd->mdcnfg = MDCNFG & 0x007f007f; | |
162 | ||
163 | twr = ns_to_cycles(sdram->twr, mem_khz); | |
164 | ||
165 | /* trp should always be >1 */ | |
166 | trp = ns_to_cycles(sdram->trp, mem_khz) - 1; | |
167 | if (trp < 1) | |
168 | trp = 1; | |
169 | ||
170 | sd->mdcnfg |= trp << 8; | |
171 | sd->mdcnfg |= trp << 24; | |
172 | sd->mdcnfg |= sdram->cas_latency << 12; | |
173 | sd->mdcnfg |= sdram->cas_latency << 28; | |
174 | sd->mdcnfg |= twr << 14; | |
175 | sd->mdcnfg |= twr << 30; | |
176 | ||
177 | sd->mdrefr = MDREFR & 0xffbffff0; | |
178 | sd->mdrefr |= 7; | |
179 | ||
180 | if (sd_khz != mem_khz) | |
181 | sd->mdrefr |= MDREFR_K1DB2; | |
182 | ||
183 | /* initial number of '1's in MDCAS + 1 */ | |
184 | set_mdcas(sd->mdcas, sd_khz >= 62000, ns_to_cycles(sdram->trcd, mem_khz)); | |
185 | ||
186 | #ifdef DEBUG | |
187 | printk("MDCNFG: %08x MDREFR: %08x MDCAS0: %08x MDCAS1: %08x MDCAS2: %08x\n", | |
188 | sd->mdcnfg, sd->mdrefr, sd->mdcas[0], sd->mdcas[1], sd->mdcas[2]); | |
189 | #endif | |
190 | } | |
191 | ||
192 | /* | |
193 | * Set the SDRAM refresh rate. | |
194 | */ | |
195 | static inline void sdram_set_refresh(u_int dri) | |
196 | { | |
197 | MDREFR = (MDREFR & 0xffff000f) | (dri << 4); | |
198 | (void) MDREFR; | |
199 | } | |
200 | ||
201 | /* | |
202 | * Update the refresh period. We do this such that we always refresh | |
203 | * the SDRAMs within their permissible period. The refresh period is | |
204 | * always a multiple of the memory clock (fixed at cpu_clock / 2). | |
205 | * | |
206 | * FIXME: we don't currently take account of burst accesses here, | |
207 | * but neither do Intels DM nor Angel. | |
208 | */ | |
209 | static void | |
210 | sdram_update_refresh(u_int cpu_khz, struct sdram_params *sdram) | |
211 | { | |
212 | u_int ns_row = (sdram->refresh * 1000) >> sdram->rows; | |
213 | u_int dri = ns_to_cycles(ns_row, cpu_khz / 2) / 32; | |
214 | ||
215 | #ifdef DEBUG | |
216 | mdelay(250); | |
217 | printk("new dri value = %d\n", dri); | |
218 | #endif | |
219 | ||
220 | sdram_set_refresh(dri); | |
221 | } | |
222 | ||
223 | /* | |
224 | * Ok, set the CPU frequency. | |
225 | */ | |
226 | static int sa1110_target(struct cpufreq_policy *policy, | |
227 | unsigned int target_freq, | |
228 | unsigned int relation) | |
229 | { | |
230 | struct sdram_params *sdram = &sdram_params; | |
231 | struct cpufreq_freqs freqs; | |
232 | struct sdram_info sd; | |
233 | unsigned long flags; | |
234 | unsigned int ppcr, unused; | |
235 | ||
236 | switch(relation){ | |
237 | case CPUFREQ_RELATION_L: | |
238 | ppcr = sa11x0_freq_to_ppcr(target_freq); | |
239 | if (sa11x0_ppcr_to_freq(ppcr) > policy->max) | |
240 | ppcr--; | |
241 | break; | |
242 | case CPUFREQ_RELATION_H: | |
243 | ppcr = sa11x0_freq_to_ppcr(target_freq); | |
244 | if (ppcr && (sa11x0_ppcr_to_freq(ppcr) > target_freq) && | |
245 | (sa11x0_ppcr_to_freq(ppcr-1) >= policy->min)) | |
246 | ppcr--; | |
247 | break; | |
248 | default: | |
249 | return -EINVAL; | |
250 | } | |
251 | ||
252 | freqs.old = sa11x0_getspeed(0); | |
253 | freqs.new = sa11x0_ppcr_to_freq(ppcr); | |
254 | freqs.cpu = 0; | |
255 | ||
256 | sdram_calculate_timing(&sd, freqs.new, sdram); | |
257 | ||
258 | #if 0 | |
259 | /* | |
260 | * These values are wrong according to the SA1110 documentation | |
261 | * and errata, but they seem to work. Need to get a storage | |
262 | * scope on to the SDRAM signals to work out why. | |
263 | */ | |
264 | if (policy->max < 147500) { | |
265 | sd.mdrefr |= MDREFR_K1DB2; | |
266 | sd.mdcas[0] = 0xaaaaaa7f; | |
267 | } else { | |
268 | sd.mdrefr &= ~MDREFR_K1DB2; | |
269 | sd.mdcas[0] = 0xaaaaaa9f; | |
270 | } | |
271 | sd.mdcas[1] = 0xaaaaaaaa; | |
272 | sd.mdcas[2] = 0xaaaaaaaa; | |
273 | #endif | |
274 | ||
275 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
276 | ||
277 | /* | |
278 | * The clock could be going away for some time. Set the SDRAMs | |
279 | * to refresh rapidly (every 64 memory clock cycles). To get | |
280 | * through the whole array, we need to wait 262144 mclk cycles. | |
281 | * We wait 20ms to be safe. | |
282 | */ | |
283 | sdram_set_refresh(2); | |
284 | if (!irqs_disabled()) { | |
db579554 | 285 | msleep(20); |
1da177e4 LT |
286 | } else { |
287 | mdelay(20); | |
288 | } | |
289 | ||
290 | /* | |
291 | * Reprogram the DRAM timings with interrupts disabled, and | |
292 | * ensure that we are doing this within a complete cache line. | |
293 | * This means that we won't access SDRAM for the duration of | |
294 | * the programming. | |
295 | */ | |
296 | local_irq_save(flags); | |
297 | asm("mcr p15, 0, %0, c7, c10, 4" : : "r" (0)); | |
298 | udelay(10); | |
299 | __asm__ __volatile__(" \n\ | |
300 | b 2f \n\ | |
301 | .align 5 \n\ | |
302 | 1: str %3, [%1, #0] @ MDCNFG \n\ | |
303 | str %4, [%1, #28] @ MDREFR \n\ | |
304 | str %5, [%1, #4] @ MDCAS0 \n\ | |
305 | str %6, [%1, #8] @ MDCAS1 \n\ | |
306 | str %7, [%1, #12] @ MDCAS2 \n\ | |
307 | str %8, [%2, #0] @ PPCR \n\ | |
308 | ldr %0, [%1, #0] \n\ | |
309 | b 3f \n\ | |
310 | 2: b 1b \n\ | |
311 | 3: nop \n\ | |
312 | nop" | |
313 | : "=&r" (unused) | |
314 | : "r" (&MDCNFG), "r" (&PPCR), "0" (sd.mdcnfg), | |
315 | "r" (sd.mdrefr), "r" (sd.mdcas[0]), | |
316 | "r" (sd.mdcas[1]), "r" (sd.mdcas[2]), "r" (ppcr)); | |
317 | local_irq_restore(flags); | |
318 | ||
319 | /* | |
320 | * Now, return the SDRAM refresh back to normal. | |
321 | */ | |
322 | sdram_update_refresh(freqs.new, sdram); | |
323 | ||
324 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
325 | ||
326 | return 0; | |
327 | } | |
328 | ||
329 | static int __init sa1110_cpu_init(struct cpufreq_policy *policy) | |
330 | { | |
331 | if (policy->cpu != 0) | |
332 | return -EINVAL; | |
333 | policy->cur = policy->min = policy->max = sa11x0_getspeed(0); | |
334 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
335 | policy->cpuinfo.min_freq = 59000; | |
336 | policy->cpuinfo.max_freq = 287000; | |
337 | policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; | |
338 | return 0; | |
339 | } | |
340 | ||
341 | static struct cpufreq_driver sa1110_driver = { | |
342 | .flags = CPUFREQ_STICKY, | |
343 | .verify = sa11x0_verify_speed, | |
344 | .target = sa1110_target, | |
345 | .get = sa11x0_getspeed, | |
346 | .init = sa1110_cpu_init, | |
347 | .name = "sa1110", | |
348 | }; | |
349 | ||
ba532011 RK |
350 | static struct sdram_params *sa1110_find_sdram(const char *name) |
351 | { | |
352 | struct sdram_params *sdram; | |
353 | ||
354 | for (sdram = sdram_tbl; sdram < sdram_tbl + ARRAY_SIZE(sdram_tbl); sdram++) | |
355 | if (strcmp(name, sdram->name) == 0) | |
356 | return sdram; | |
357 | ||
358 | return NULL; | |
359 | } | |
360 | ||
361 | static char sdram_name[16]; | |
362 | ||
1da177e4 LT |
363 | static int __init sa1110_clk_init(void) |
364 | { | |
ba532011 RK |
365 | struct sdram_params *sdram; |
366 | const char *name = sdram_name; | |
1da177e4 | 367 | |
ba532011 RK |
368 | if (!name[0]) { |
369 | if (machine_is_assabet()) | |
370 | name = "TC59SM716-CL3"; | |
1da177e4 | 371 | |
ba532011 RK |
372 | if (machine_is_pt_system3()) |
373 | name = "K4S641632D"; | |
1da177e4 | 374 | |
ba532011 RK |
375 | if (machine_is_h3100()) |
376 | name = "KM416S4030CT"; | |
48e3becb KE |
377 | if (machine_is_jornada720()) |
378 | name = "K4S281632B-1H"; | |
ba532011 | 379 | } |
1da177e4 | 380 | |
ba532011 | 381 | sdram = sa1110_find_sdram(name); |
1da177e4 LT |
382 | if (sdram) { |
383 | printk(KERN_DEBUG "SDRAM: tck: %d trcd: %d trp: %d" | |
384 | " twr: %d refresh: %d cas_latency: %d\n", | |
385 | sdram->tck, sdram->trcd, sdram->trp, | |
386 | sdram->twr, sdram->refresh, sdram->cas_latency); | |
387 | ||
388 | memcpy(&sdram_params, sdram, sizeof(sdram_params)); | |
389 | ||
390 | return cpufreq_register_driver(&sa1110_driver); | |
391 | } | |
392 | ||
393 | return 0; | |
394 | } | |
395 | ||
ba532011 | 396 | module_param_string(sdram, sdram_name, sizeof(sdram_name), 0); |
1da177e4 | 397 | arch_initcall(sa1110_clk_init); |