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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/arch/arm/mach-sa1100/cpu-sa1110.c | |
4 | * | |
5 | * Copyright (C) 2001 Russell King | |
6 | * | |
1da177e4 LT |
7 | * Note: there are two erratas that apply to the SA1110 here: |
8 | * 7 - SDRAM auto-power-up failure (rev A0) | |
9 | * 13 - Corruption of internal register reads/writes following | |
10 | * SDRAM reads (rev A0, B0, B1) | |
11 | * | |
12 | * We ignore rev. A0 and B0 devices; I don't think they're worth supporting. | |
ba532011 RK |
13 | * |
14 | * The SDRAM type can be passed on the command line as cpu_sa1110.sdram=type | |
1da177e4 | 15 | */ |
1da177e4 LT |
16 | #include <linux/cpufreq.h> |
17 | #include <linux/delay.h> | |
18 | #include <linux/init.h> | |
3169663a | 19 | #include <linux/io.h> |
9f15d2ca MRJ |
20 | #include <linux/kernel.h> |
21 | #include <linux/moduleparam.h> | |
22 | #include <linux/types.h> | |
1da177e4 | 23 | |
0ba8b9b2 | 24 | #include <asm/cputype.h> |
1da177e4 | 25 | #include <asm/mach-types.h> |
9f15d2ca | 26 | |
59a2e613 | 27 | #include <mach/generic.h> |
9f15d2ca | 28 | #include <mach/hardware.h> |
1da177e4 | 29 | |
1da177e4 LT |
30 | #undef DEBUG |
31 | ||
1da177e4 | 32 | struct sdram_params { |
9f15d2ca | 33 | const char name[20]; |
1da177e4 LT |
34 | u_char rows; /* bits */ |
35 | u_char cas_latency; /* cycles */ | |
36 | u_char tck; /* clock cycle time (ns) */ | |
37 | u_char trcd; /* activate to r/w (ns) */ | |
38 | u_char trp; /* precharge to activate (ns) */ | |
39 | u_char twr; /* write recovery time (ns) */ | |
40 | u_short refresh; /* refresh time for array (us) */ | |
41 | }; | |
42 | ||
43 | struct sdram_info { | |
44 | u_int mdcnfg; | |
45 | u_int mdrefr; | |
46 | u_int mdcas[3]; | |
47 | }; | |
48 | ||
ba532011 RK |
49 | static struct sdram_params sdram_tbl[] __initdata = { |
50 | { /* Toshiba TC59SM716 CL2 */ | |
51 | .name = "TC59SM716-CL2", | |
52 | .rows = 12, | |
53 | .tck = 10, | |
54 | .trcd = 20, | |
55 | .trp = 20, | |
56 | .twr = 10, | |
57 | .refresh = 64000, | |
58 | .cas_latency = 2, | |
59 | }, { /* Toshiba TC59SM716 CL3 */ | |
60 | .name = "TC59SM716-CL3", | |
61 | .rows = 12, | |
62 | .tck = 8, | |
63 | .trcd = 20, | |
64 | .trp = 20, | |
65 | .twr = 8, | |
66 | .refresh = 64000, | |
67 | .cas_latency = 3, | |
68 | }, { /* Samsung K4S641632D TC75 */ | |
69 | .name = "K4S641632D", | |
70 | .rows = 14, | |
71 | .tck = 9, | |
72 | .trcd = 27, | |
73 | .trp = 20, | |
74 | .twr = 9, | |
75 | .refresh = 64000, | |
76 | .cas_latency = 3, | |
93982535 KE |
77 | }, { /* Samsung K4S281632B-1H */ |
78 | .name = "K4S281632B-1H", | |
79 | .rows = 12, | |
80 | .tck = 10, | |
81 | .trp = 20, | |
82 | .twr = 10, | |
83 | .refresh = 64000, | |
84 | .cas_latency = 3, | |
ba532011 RK |
85 | }, { /* Samsung KM416S4030CT */ |
86 | .name = "KM416S4030CT", | |
87 | .rows = 13, | |
88 | .tck = 8, | |
89 | .trcd = 24, /* 3 CLKs */ | |
90 | .trp = 24, /* 3 CLKs */ | |
91 | .twr = 16, /* Trdl: 2 CLKs */ | |
92 | .refresh = 64000, | |
93 | .cas_latency = 3, | |
94 | }, { /* Winbond W982516AH75L CL3 */ | |
95 | .name = "W982516AH75L", | |
96 | .rows = 16, | |
97 | .tck = 8, | |
98 | .trcd = 20, | |
99 | .trp = 20, | |
100 | .twr = 8, | |
101 | .refresh = 64000, | |
102 | .cas_latency = 3, | |
9f15d2ca MRJ |
103 | }, { /* Micron MT48LC8M16A2TG-75 */ |
104 | .name = "MT48LC8M16A2TG-75", | |
105 | .rows = 12, | |
106 | .tck = 8, | |
107 | .trcd = 20, | |
108 | .trp = 20, | |
109 | .twr = 8, | |
110 | .refresh = 64000, | |
111 | .cas_latency = 3, | |
ba532011 | 112 | }, |
1da177e4 LT |
113 | }; |
114 | ||
115 | static struct sdram_params sdram_params; | |
116 | ||
117 | /* | |
118 | * Given a period in ns and frequency in khz, calculate the number of | |
119 | * cycles of frequency in period. Note that we round up to the next | |
120 | * cycle, even if we are only slightly over. | |
121 | */ | |
122 | static inline u_int ns_to_cycles(u_int ns, u_int khz) | |
123 | { | |
124 | return (ns * khz + 999999) / 1000000; | |
125 | } | |
126 | ||
127 | /* | |
128 | * Create the MDCAS register bit pattern. | |
129 | */ | |
130 | static inline void set_mdcas(u_int *mdcas, int delayed, u_int rcd) | |
131 | { | |
132 | u_int shift; | |
133 | ||
134 | rcd = 2 * rcd - 1; | |
135 | shift = delayed + 1 + rcd; | |
136 | ||
137 | mdcas[0] = (1 << rcd) - 1; | |
138 | mdcas[0] |= 0x55555555 << shift; | |
139 | mdcas[1] = mdcas[2] = 0x55555555 << (shift & 1); | |
140 | } | |
141 | ||
142 | static void | |
143 | sdram_calculate_timing(struct sdram_info *sd, u_int cpu_khz, | |
144 | struct sdram_params *sdram) | |
145 | { | |
146 | u_int mem_khz, sd_khz, trp, twr; | |
147 | ||
148 | mem_khz = cpu_khz / 2; | |
149 | sd_khz = mem_khz; | |
150 | ||
151 | /* | |
152 | * If SDCLK would invalidate the SDRAM timings, | |
153 | * run SDCLK at half speed. | |
154 | * | |
155 | * CPU steppings prior to B2 must either run the memory at | |
156 | * half speed or use delayed read latching (errata 13). | |
157 | */ | |
158 | if ((ns_to_cycles(sdram->tck, sd_khz) > 1) || | |
83809b90 | 159 | (read_cpuid_revision() < ARM_CPU_REV_SA1110_B2 && sd_khz < 62000)) |
1da177e4 LT |
160 | sd_khz /= 2; |
161 | ||
162 | sd->mdcnfg = MDCNFG & 0x007f007f; | |
163 | ||
164 | twr = ns_to_cycles(sdram->twr, mem_khz); | |
165 | ||
166 | /* trp should always be >1 */ | |
167 | trp = ns_to_cycles(sdram->trp, mem_khz) - 1; | |
168 | if (trp < 1) | |
169 | trp = 1; | |
170 | ||
171 | sd->mdcnfg |= trp << 8; | |
172 | sd->mdcnfg |= trp << 24; | |
173 | sd->mdcnfg |= sdram->cas_latency << 12; | |
174 | sd->mdcnfg |= sdram->cas_latency << 28; | |
175 | sd->mdcnfg |= twr << 14; | |
176 | sd->mdcnfg |= twr << 30; | |
177 | ||
178 | sd->mdrefr = MDREFR & 0xffbffff0; | |
179 | sd->mdrefr |= 7; | |
180 | ||
181 | if (sd_khz != mem_khz) | |
182 | sd->mdrefr |= MDREFR_K1DB2; | |
183 | ||
184 | /* initial number of '1's in MDCAS + 1 */ | |
47bb3b31 MRJ |
185 | set_mdcas(sd->mdcas, sd_khz >= 62000, |
186 | ns_to_cycles(sdram->trcd, mem_khz)); | |
1da177e4 LT |
187 | |
188 | #ifdef DEBUG | |
47bb3b31 MRJ |
189 | printk(KERN_DEBUG "MDCNFG: %08x MDREFR: %08x MDCAS0: %08x MDCAS1: %08x MDCAS2: %08x\n", |
190 | sd->mdcnfg, sd->mdrefr, sd->mdcas[0], sd->mdcas[1], | |
191 | sd->mdcas[2]); | |
1da177e4 LT |
192 | #endif |
193 | } | |
194 | ||
195 | /* | |
196 | * Set the SDRAM refresh rate. | |
197 | */ | |
198 | static inline void sdram_set_refresh(u_int dri) | |
199 | { | |
200 | MDREFR = (MDREFR & 0xffff000f) | (dri << 4); | |
201 | (void) MDREFR; | |
202 | } | |
203 | ||
204 | /* | |
205 | * Update the refresh period. We do this such that we always refresh | |
206 | * the SDRAMs within their permissible period. The refresh period is | |
207 | * always a multiple of the memory clock (fixed at cpu_clock / 2). | |
208 | * | |
209 | * FIXME: we don't currently take account of burst accesses here, | |
210 | * but neither do Intels DM nor Angel. | |
211 | */ | |
212 | static void | |
213 | sdram_update_refresh(u_int cpu_khz, struct sdram_params *sdram) | |
214 | { | |
215 | u_int ns_row = (sdram->refresh * 1000) >> sdram->rows; | |
216 | u_int dri = ns_to_cycles(ns_row, cpu_khz / 2) / 32; | |
217 | ||
218 | #ifdef DEBUG | |
219 | mdelay(250); | |
47bb3b31 | 220 | printk(KERN_DEBUG "new dri value = %d\n", dri); |
1da177e4 LT |
221 | #endif |
222 | ||
223 | sdram_set_refresh(dri); | |
224 | } | |
225 | ||
226 | /* | |
93982535 | 227 | * Ok, set the CPU frequency. |
1da177e4 | 228 | */ |
9c0ebcf7 | 229 | static int sa1110_target(struct cpufreq_policy *policy, unsigned int ppcr) |
1da177e4 LT |
230 | { |
231 | struct sdram_params *sdram = &sdram_params; | |
1da177e4 LT |
232 | struct sdram_info sd; |
233 | unsigned long flags; | |
9c0ebcf7 | 234 | unsigned int unused; |
1da177e4 | 235 | |
d4019f0a | 236 | sdram_calculate_timing(&sd, sa11x0_freq_table[ppcr].frequency, sdram); |
1da177e4 LT |
237 | |
238 | #if 0 | |
239 | /* | |
240 | * These values are wrong according to the SA1110 documentation | |
241 | * and errata, but they seem to work. Need to get a storage | |
242 | * scope on to the SDRAM signals to work out why. | |
243 | */ | |
244 | if (policy->max < 147500) { | |
245 | sd.mdrefr |= MDREFR_K1DB2; | |
246 | sd.mdcas[0] = 0xaaaaaa7f; | |
247 | } else { | |
248 | sd.mdrefr &= ~MDREFR_K1DB2; | |
249 | sd.mdcas[0] = 0xaaaaaa9f; | |
250 | } | |
251 | sd.mdcas[1] = 0xaaaaaaaa; | |
252 | sd.mdcas[2] = 0xaaaaaaaa; | |
253 | #endif | |
254 | ||
1da177e4 LT |
255 | /* |
256 | * The clock could be going away for some time. Set the SDRAMs | |
257 | * to refresh rapidly (every 64 memory clock cycles). To get | |
258 | * through the whole array, we need to wait 262144 mclk cycles. | |
259 | * We wait 20ms to be safe. | |
260 | */ | |
261 | sdram_set_refresh(2); | |
47bb3b31 | 262 | if (!irqs_disabled()) |
db579554 | 263 | msleep(20); |
47bb3b31 | 264 | else |
1da177e4 | 265 | mdelay(20); |
1da177e4 LT |
266 | |
267 | /* | |
268 | * Reprogram the DRAM timings with interrupts disabled, and | |
269 | * ensure that we are doing this within a complete cache line. | |
270 | * This means that we won't access SDRAM for the duration of | |
271 | * the programming. | |
272 | */ | |
273 | local_irq_save(flags); | |
274 | asm("mcr p15, 0, %0, c7, c10, 4" : : "r" (0)); | |
275 | udelay(10); | |
47bb3b31 | 276 | __asm__ __volatile__("\n\ |
1da177e4 LT |
277 | b 2f \n\ |
278 | .align 5 \n\ | |
279 | 1: str %3, [%1, #0] @ MDCNFG \n\ | |
280 | str %4, [%1, #28] @ MDREFR \n\ | |
281 | str %5, [%1, #4] @ MDCAS0 \n\ | |
282 | str %6, [%1, #8] @ MDCAS1 \n\ | |
283 | str %7, [%1, #12] @ MDCAS2 \n\ | |
284 | str %8, [%2, #0] @ PPCR \n\ | |
285 | ldr %0, [%1, #0] \n\ | |
286 | b 3f \n\ | |
287 | 2: b 1b \n\ | |
288 | 3: nop \n\ | |
289 | nop" | |
290 | : "=&r" (unused) | |
291 | : "r" (&MDCNFG), "r" (&PPCR), "0" (sd.mdcnfg), | |
292 | "r" (sd.mdrefr), "r" (sd.mdcas[0]), | |
293 | "r" (sd.mdcas[1]), "r" (sd.mdcas[2]), "r" (ppcr)); | |
294 | local_irq_restore(flags); | |
295 | ||
296 | /* | |
297 | * Now, return the SDRAM refresh back to normal. | |
298 | */ | |
d4019f0a | 299 | sdram_update_refresh(sa11x0_freq_table[ppcr].frequency, sdram); |
1da177e4 LT |
300 | |
301 | return 0; | |
302 | } | |
303 | ||
304 | static int __init sa1110_cpu_init(struct cpufreq_policy *policy) | |
305 | { | |
c4dcc8a1 VK |
306 | cpufreq_generic_init(policy, sa11x0_freq_table, 0); |
307 | return 0; | |
1da177e4 LT |
308 | } |
309 | ||
9f15d2ca MRJ |
310 | /* sa1110_driver needs __refdata because it must remain after init registers |
311 | * it with cpufreq_register_driver() */ | |
312 | static struct cpufreq_driver sa1110_driver __refdata = { | |
5ae4a4b4 | 313 | .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK | |
fe829ed8 | 314 | CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING, |
dd9f2639 | 315 | .verify = cpufreq_generic_frequency_table_verify, |
9c0ebcf7 | 316 | .target_index = sa1110_target, |
1da177e4 LT |
317 | .get = sa11x0_getspeed, |
318 | .init = sa1110_cpu_init, | |
319 | .name = "sa1110", | |
320 | }; | |
321 | ||
ba532011 RK |
322 | static struct sdram_params *sa1110_find_sdram(const char *name) |
323 | { | |
324 | struct sdram_params *sdram; | |
325 | ||
47bb3b31 MRJ |
326 | for (sdram = sdram_tbl; sdram < sdram_tbl + ARRAY_SIZE(sdram_tbl); |
327 | sdram++) | |
ba532011 RK |
328 | if (strcmp(name, sdram->name) == 0) |
329 | return sdram; | |
330 | ||
331 | return NULL; | |
332 | } | |
333 | ||
334 | static char sdram_name[16]; | |
335 | ||
1da177e4 LT |
336 | static int __init sa1110_clk_init(void) |
337 | { | |
ba532011 RK |
338 | struct sdram_params *sdram; |
339 | const char *name = sdram_name; | |
1da177e4 | 340 | |
e5992c05 DA |
341 | if (!cpu_is_sa1110()) |
342 | return -ENODEV; | |
343 | ||
ba532011 RK |
344 | if (!name[0]) { |
345 | if (machine_is_assabet()) | |
346 | name = "TC59SM716-CL3"; | |
ba532011 RK |
347 | if (machine_is_pt_system3()) |
348 | name = "K4S641632D"; | |
ba532011 RK |
349 | if (machine_is_h3100()) |
350 | name = "KM416S4030CT"; | |
97d496bf | 351 | if (machine_is_jornada720() || machine_is_h3600()) |
47bb3b31 | 352 | name = "K4S281632B-1H"; |
9f15d2ca MRJ |
353 | if (machine_is_nanoengine()) |
354 | name = "MT48LC8M16A2TG-75"; | |
ba532011 | 355 | } |
1da177e4 | 356 | |
ba532011 | 357 | sdram = sa1110_find_sdram(name); |
1da177e4 LT |
358 | if (sdram) { |
359 | printk(KERN_DEBUG "SDRAM: tck: %d trcd: %d trp: %d" | |
360 | " twr: %d refresh: %d cas_latency: %d\n", | |
361 | sdram->tck, sdram->trcd, sdram->trp, | |
362 | sdram->twr, sdram->refresh, sdram->cas_latency); | |
363 | ||
364 | memcpy(&sdram_params, sdram, sizeof(sdram_params)); | |
365 | ||
366 | return cpufreq_register_driver(&sa1110_driver); | |
367 | } | |
368 | ||
369 | return 0; | |
370 | } | |
371 | ||
ba532011 | 372 | module_param_string(sdram, sdram_name, sizeof(sdram_name), 0); |
1da177e4 | 373 | arch_initcall(sa1110_clk_init); |