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bf224335 PA |
1 | /* |
2 | * Error Location Module | |
3 | * | |
4 | * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/ | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | */ | |
17 | ||
18 | #include <linux/platform_device.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/interrupt.h> | |
21 | #include <linux/io.h> | |
22 | #include <linux/of.h> | |
11f164d1 | 23 | #include <linux/sched.h> |
bf224335 PA |
24 | #include <linux/pm_runtime.h> |
25 | #include <linux/platform_data/elm.h> | |
26 | ||
11f164d1 | 27 | #define ELM_SYSCONFIG 0x010 |
bf224335 PA |
28 | #define ELM_IRQSTATUS 0x018 |
29 | #define ELM_IRQENABLE 0x01c | |
30 | #define ELM_LOCATION_CONFIG 0x020 | |
31 | #define ELM_PAGE_CTRL 0x080 | |
32 | #define ELM_SYNDROME_FRAGMENT_0 0x400 | |
11f164d1 | 33 | #define ELM_SYNDROME_FRAGMENT_1 0x404 |
34 | #define ELM_SYNDROME_FRAGMENT_2 0x408 | |
35 | #define ELM_SYNDROME_FRAGMENT_3 0x40c | |
36 | #define ELM_SYNDROME_FRAGMENT_4 0x410 | |
37 | #define ELM_SYNDROME_FRAGMENT_5 0x414 | |
bf224335 PA |
38 | #define ELM_SYNDROME_FRAGMENT_6 0x418 |
39 | #define ELM_LOCATION_STATUS 0x800 | |
40 | #define ELM_ERROR_LOCATION_0 0x880 | |
41 | ||
42 | /* ELM Interrupt Status Register */ | |
43 | #define INTR_STATUS_PAGE_VALID BIT(8) | |
44 | ||
45 | /* ELM Interrupt Enable Register */ | |
46 | #define INTR_EN_PAGE_MASK BIT(8) | |
47 | ||
48 | /* ELM Location Configuration Register */ | |
49 | #define ECC_BCH_LEVEL_MASK 0x3 | |
50 | ||
51 | /* ELM syndrome */ | |
52 | #define ELM_SYNDROME_VALID BIT(16) | |
53 | ||
54 | /* ELM_LOCATION_STATUS Register */ | |
55 | #define ECC_CORRECTABLE_MASK BIT(8) | |
56 | #define ECC_NB_ERRORS_MASK 0x1f | |
57 | ||
58 | /* ELM_ERROR_LOCATION_0-15 Registers */ | |
59 | #define ECC_ERROR_LOCATION_MASK 0x1fff | |
60 | ||
61 | #define ELM_ECC_SIZE 0x7ff | |
62 | ||
63 | #define SYNDROME_FRAGMENT_REG_SIZE 0x40 | |
64 | #define ERROR_LOCATION_SIZE 0x100 | |
65 | ||
11f164d1 | 66 | struct elm_registers { |
67 | u32 elm_irqenable; | |
68 | u32 elm_sysconfig; | |
69 | u32 elm_location_config; | |
70 | u32 elm_page_ctrl; | |
71 | u32 elm_syndrome_fragment_6[ERROR_VECTOR_MAX]; | |
72 | u32 elm_syndrome_fragment_5[ERROR_VECTOR_MAX]; | |
73 | u32 elm_syndrome_fragment_4[ERROR_VECTOR_MAX]; | |
74 | u32 elm_syndrome_fragment_3[ERROR_VECTOR_MAX]; | |
75 | u32 elm_syndrome_fragment_2[ERROR_VECTOR_MAX]; | |
76 | u32 elm_syndrome_fragment_1[ERROR_VECTOR_MAX]; | |
77 | u32 elm_syndrome_fragment_0[ERROR_VECTOR_MAX]; | |
78 | }; | |
79 | ||
bf224335 PA |
80 | struct elm_info { |
81 | struct device *dev; | |
82 | void __iomem *elm_base; | |
83 | struct completion elm_completion; | |
84 | struct list_head list; | |
85 | enum bch_ecc bch_type; | |
11f164d1 | 86 | struct elm_registers elm_regs; |
bf224335 PA |
87 | }; |
88 | ||
89 | static LIST_HEAD(elm_devices); | |
90 | ||
91 | static void elm_write_reg(struct elm_info *info, int offset, u32 val) | |
92 | { | |
93 | writel(val, info->elm_base + offset); | |
94 | } | |
95 | ||
96 | static u32 elm_read_reg(struct elm_info *info, int offset) | |
97 | { | |
98 | return readl(info->elm_base + offset); | |
99 | } | |
100 | ||
101 | /** | |
102 | * elm_config - Configure ELM module | |
103 | * @dev: ELM device | |
104 | * @bch_type: Type of BCH ecc | |
105 | */ | |
ad245789 | 106 | int elm_config(struct device *dev, enum bch_ecc bch_type) |
bf224335 PA |
107 | { |
108 | u32 reg_val; | |
109 | struct elm_info *info = dev_get_drvdata(dev); | |
110 | ||
ad245789 DM |
111 | if (!info) { |
112 | dev_err(dev, "Unable to configure elm - device not probed?\n"); | |
113 | return -ENODEV; | |
114 | } | |
115 | ||
bf224335 PA |
116 | reg_val = (bch_type & ECC_BCH_LEVEL_MASK) | (ELM_ECC_SIZE << 16); |
117 | elm_write_reg(info, ELM_LOCATION_CONFIG, reg_val); | |
118 | info->bch_type = bch_type; | |
ad245789 DM |
119 | |
120 | return 0; | |
bf224335 PA |
121 | } |
122 | EXPORT_SYMBOL(elm_config); | |
123 | ||
124 | /** | |
125 | * elm_configure_page_mode - Enable/Disable page mode | |
126 | * @info: elm info | |
127 | * @index: index number of syndrome fragment vector | |
128 | * @enable: enable/disable flag for page mode | |
129 | * | |
130 | * Enable page mode for syndrome fragment index | |
131 | */ | |
132 | static void elm_configure_page_mode(struct elm_info *info, int index, | |
133 | bool enable) | |
134 | { | |
135 | u32 reg_val; | |
136 | ||
137 | reg_val = elm_read_reg(info, ELM_PAGE_CTRL); | |
138 | if (enable) | |
139 | reg_val |= BIT(index); /* enable page mode */ | |
140 | else | |
141 | reg_val &= ~BIT(index); /* disable page mode */ | |
142 | ||
143 | elm_write_reg(info, ELM_PAGE_CTRL, reg_val); | |
144 | } | |
145 | ||
146 | /** | |
147 | * elm_load_syndrome - Load ELM syndrome reg | |
148 | * @info: elm info | |
149 | * @err_vec: elm error vectors | |
150 | * @ecc: buffer with calculated ecc | |
151 | * | |
152 | * Load syndrome fragment registers with calculated ecc in reverse order. | |
153 | */ | |
154 | static void elm_load_syndrome(struct elm_info *info, | |
155 | struct elm_errorvec *err_vec, u8 *ecc) | |
156 | { | |
157 | int i, offset; | |
158 | u32 val; | |
159 | ||
160 | for (i = 0; i < ERROR_VECTOR_MAX; i++) { | |
161 | ||
162 | /* Check error reported */ | |
163 | if (err_vec[i].error_reported) { | |
164 | elm_configure_page_mode(info, i, true); | |
165 | offset = ELM_SYNDROME_FRAGMENT_0 + | |
166 | SYNDROME_FRAGMENT_REG_SIZE * i; | |
167 | ||
168 | /* BCH8 */ | |
169 | if (info->bch_type) { | |
170 | ||
171 | /* syndrome fragment 0 = ecc[9-12B] */ | |
172 | val = cpu_to_be32(*(u32 *) &ecc[9]); | |
173 | elm_write_reg(info, offset, val); | |
174 | ||
175 | /* syndrome fragment 1 = ecc[5-8B] */ | |
176 | offset += 4; | |
177 | val = cpu_to_be32(*(u32 *) &ecc[5]); | |
178 | elm_write_reg(info, offset, val); | |
179 | ||
180 | /* syndrome fragment 2 = ecc[1-4B] */ | |
181 | offset += 4; | |
182 | val = cpu_to_be32(*(u32 *) &ecc[1]); | |
183 | elm_write_reg(info, offset, val); | |
184 | ||
185 | /* syndrome fragment 3 = ecc[0B] */ | |
186 | offset += 4; | |
187 | val = ecc[0]; | |
188 | elm_write_reg(info, offset, val); | |
189 | } else { | |
190 | /* syndrome fragment 0 = ecc[20-52b] bits */ | |
191 | val = (cpu_to_be32(*(u32 *) &ecc[3]) >> 4) | | |
192 | ((ecc[2] & 0xf) << 28); | |
193 | elm_write_reg(info, offset, val); | |
194 | ||
195 | /* syndrome fragment 1 = ecc[0-20b] bits */ | |
196 | offset += 4; | |
197 | val = cpu_to_be32(*(u32 *) &ecc[0]) >> 12; | |
198 | elm_write_reg(info, offset, val); | |
199 | } | |
200 | } | |
201 | ||
202 | /* Update ecc pointer with ecc byte size */ | |
203 | ecc += info->bch_type ? BCH8_SIZE : BCH4_SIZE; | |
204 | } | |
205 | } | |
206 | ||
207 | /** | |
208 | * elm_start_processing - start elm syndrome processing | |
209 | * @info: elm info | |
210 | * @err_vec: elm error vectors | |
211 | * | |
212 | * Set syndrome valid bit for syndrome fragment registers for which | |
213 | * elm syndrome fragment registers are loaded. This enables elm module | |
214 | * to start processing syndrome vectors. | |
215 | */ | |
216 | static void elm_start_processing(struct elm_info *info, | |
217 | struct elm_errorvec *err_vec) | |
218 | { | |
219 | int i, offset; | |
220 | u32 reg_val; | |
221 | ||
222 | /* | |
223 | * Set syndrome vector valid, so that ELM module | |
224 | * will process it for vectors error is reported | |
225 | */ | |
226 | for (i = 0; i < ERROR_VECTOR_MAX; i++) { | |
227 | if (err_vec[i].error_reported) { | |
228 | offset = ELM_SYNDROME_FRAGMENT_6 + | |
229 | SYNDROME_FRAGMENT_REG_SIZE * i; | |
230 | reg_val = elm_read_reg(info, offset); | |
231 | reg_val |= ELM_SYNDROME_VALID; | |
232 | elm_write_reg(info, offset, reg_val); | |
233 | } | |
234 | } | |
235 | } | |
236 | ||
237 | /** | |
238 | * elm_error_correction - locate correctable error position | |
239 | * @info: elm info | |
240 | * @err_vec: elm error vectors | |
241 | * | |
242 | * On completion of processing by elm module, error location status | |
243 | * register updated with correctable/uncorrectable error information. | |
244 | * In case of correctable errors, number of errors located from | |
245 | * elm location status register & read the positions from | |
246 | * elm error location register. | |
247 | */ | |
248 | static void elm_error_correction(struct elm_info *info, | |
249 | struct elm_errorvec *err_vec) | |
250 | { | |
251 | int i, j, errors = 0; | |
252 | int offset; | |
253 | u32 reg_val; | |
254 | ||
255 | for (i = 0; i < ERROR_VECTOR_MAX; i++) { | |
256 | ||
257 | /* Check error reported */ | |
258 | if (err_vec[i].error_reported) { | |
259 | offset = ELM_LOCATION_STATUS + ERROR_LOCATION_SIZE * i; | |
260 | reg_val = elm_read_reg(info, offset); | |
261 | ||
262 | /* Check correctable error or not */ | |
263 | if (reg_val & ECC_CORRECTABLE_MASK) { | |
264 | offset = ELM_ERROR_LOCATION_0 + | |
265 | ERROR_LOCATION_SIZE * i; | |
266 | ||
267 | /* Read count of correctable errors */ | |
268 | err_vec[i].error_count = reg_val & | |
269 | ECC_NB_ERRORS_MASK; | |
270 | ||
271 | /* Update the error locations in error vector */ | |
272 | for (j = 0; j < err_vec[i].error_count; j++) { | |
273 | ||
274 | reg_val = elm_read_reg(info, offset); | |
275 | err_vec[i].error_loc[j] = reg_val & | |
276 | ECC_ERROR_LOCATION_MASK; | |
277 | ||
278 | /* Update error location register */ | |
279 | offset += 4; | |
280 | } | |
281 | ||
282 | errors += err_vec[i].error_count; | |
283 | } else { | |
284 | err_vec[i].error_uncorrectable = true; | |
285 | } | |
286 | ||
287 | /* Clearing interrupts for processed error vectors */ | |
288 | elm_write_reg(info, ELM_IRQSTATUS, BIT(i)); | |
289 | ||
290 | /* Disable page mode */ | |
291 | elm_configure_page_mode(info, i, false); | |
292 | } | |
293 | } | |
294 | } | |
295 | ||
296 | /** | |
297 | * elm_decode_bch_error_page - Locate error position | |
298 | * @dev: device pointer | |
299 | * @ecc_calc: calculated ECC bytes from GPMC | |
300 | * @err_vec: elm error vectors | |
301 | * | |
302 | * Called with one or more error reported vectors & vectors with | |
303 | * error reported is updated in err_vec[].error_reported | |
304 | */ | |
305 | void elm_decode_bch_error_page(struct device *dev, u8 *ecc_calc, | |
306 | struct elm_errorvec *err_vec) | |
307 | { | |
308 | struct elm_info *info = dev_get_drvdata(dev); | |
309 | u32 reg_val; | |
310 | ||
311 | /* Enable page mode interrupt */ | |
312 | reg_val = elm_read_reg(info, ELM_IRQSTATUS); | |
313 | elm_write_reg(info, ELM_IRQSTATUS, reg_val & INTR_STATUS_PAGE_VALID); | |
314 | elm_write_reg(info, ELM_IRQENABLE, INTR_EN_PAGE_MASK); | |
315 | ||
316 | /* Load valid ecc byte to syndrome fragment register */ | |
317 | elm_load_syndrome(info, err_vec, ecc_calc); | |
318 | ||
319 | /* Enable syndrome processing for which syndrome fragment is updated */ | |
320 | elm_start_processing(info, err_vec); | |
321 | ||
322 | /* Wait for ELM module to finish locating error correction */ | |
323 | wait_for_completion(&info->elm_completion); | |
324 | ||
325 | /* Disable page mode interrupt */ | |
326 | reg_val = elm_read_reg(info, ELM_IRQENABLE); | |
327 | elm_write_reg(info, ELM_IRQENABLE, reg_val & ~INTR_EN_PAGE_MASK); | |
328 | elm_error_correction(info, err_vec); | |
329 | } | |
330 | EXPORT_SYMBOL(elm_decode_bch_error_page); | |
331 | ||
332 | static irqreturn_t elm_isr(int this_irq, void *dev_id) | |
333 | { | |
334 | u32 reg_val; | |
335 | struct elm_info *info = dev_id; | |
336 | ||
337 | reg_val = elm_read_reg(info, ELM_IRQSTATUS); | |
338 | ||
339 | /* All error vectors processed */ | |
340 | if (reg_val & INTR_STATUS_PAGE_VALID) { | |
341 | elm_write_reg(info, ELM_IRQSTATUS, | |
342 | reg_val & INTR_STATUS_PAGE_VALID); | |
343 | complete(&info->elm_completion); | |
344 | return IRQ_HANDLED; | |
345 | } | |
346 | ||
347 | return IRQ_NONE; | |
348 | } | |
349 | ||
350 | static int elm_probe(struct platform_device *pdev) | |
351 | { | |
352 | int ret = 0; | |
353 | struct resource *res, *irq; | |
354 | struct elm_info *info; | |
355 | ||
356 | info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL); | |
357 | if (!info) { | |
358 | dev_err(&pdev->dev, "failed to allocate memory\n"); | |
359 | return -ENOMEM; | |
360 | } | |
361 | ||
362 | info->dev = &pdev->dev; | |
363 | ||
364 | irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); | |
365 | if (!irq) { | |
366 | dev_err(&pdev->dev, "no irq resource defined\n"); | |
367 | return -ENODEV; | |
368 | } | |
369 | ||
370 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
43579688 SMP |
371 | info->elm_base = devm_ioremap_resource(&pdev->dev, res); |
372 | if (IS_ERR(info->elm_base)) | |
373 | return PTR_ERR(info->elm_base); | |
bf224335 PA |
374 | |
375 | ret = devm_request_irq(&pdev->dev, irq->start, elm_isr, 0, | |
376 | pdev->name, info); | |
377 | if (ret) { | |
378 | dev_err(&pdev->dev, "failure requesting irq %i\n", irq->start); | |
379 | return ret; | |
380 | } | |
381 | ||
382 | pm_runtime_enable(&pdev->dev); | |
383 | if (pm_runtime_get_sync(&pdev->dev)) { | |
384 | ret = -EINVAL; | |
385 | pm_runtime_disable(&pdev->dev); | |
386 | dev_err(&pdev->dev, "can't enable clock\n"); | |
387 | return ret; | |
388 | } | |
389 | ||
390 | init_completion(&info->elm_completion); | |
391 | INIT_LIST_HEAD(&info->list); | |
392 | list_add(&info->list, &elm_devices); | |
393 | platform_set_drvdata(pdev, info); | |
394 | return ret; | |
395 | } | |
396 | ||
397 | static int elm_remove(struct platform_device *pdev) | |
398 | { | |
399 | pm_runtime_put_sync(&pdev->dev); | |
400 | pm_runtime_disable(&pdev->dev); | |
bf224335 PA |
401 | return 0; |
402 | } | |
403 | ||
11f164d1 | 404 | /** |
405 | * elm_context_save | |
406 | * saves ELM configurations to preserve them across Hardware powered-down | |
407 | */ | |
408 | static int elm_context_save(struct elm_info *info) | |
409 | { | |
410 | struct elm_registers *regs = &info->elm_regs; | |
411 | enum bch_ecc bch_type = info->bch_type; | |
412 | u32 offset = 0, i; | |
413 | ||
414 | regs->elm_irqenable = elm_read_reg(info, ELM_IRQENABLE); | |
415 | regs->elm_sysconfig = elm_read_reg(info, ELM_SYSCONFIG); | |
416 | regs->elm_location_config = elm_read_reg(info, ELM_LOCATION_CONFIG); | |
417 | regs->elm_page_ctrl = elm_read_reg(info, ELM_PAGE_CTRL); | |
418 | for (i = 0; i < ERROR_VECTOR_MAX; i++) { | |
419 | offset = i * SYNDROME_FRAGMENT_REG_SIZE; | |
420 | switch (bch_type) { | |
421 | case BCH8_ECC: | |
422 | regs->elm_syndrome_fragment_3[i] = elm_read_reg(info, | |
423 | ELM_SYNDROME_FRAGMENT_3 + offset); | |
424 | regs->elm_syndrome_fragment_2[i] = elm_read_reg(info, | |
425 | ELM_SYNDROME_FRAGMENT_2 + offset); | |
426 | case BCH4_ECC: | |
427 | regs->elm_syndrome_fragment_1[i] = elm_read_reg(info, | |
428 | ELM_SYNDROME_FRAGMENT_1 + offset); | |
429 | regs->elm_syndrome_fragment_0[i] = elm_read_reg(info, | |
430 | ELM_SYNDROME_FRAGMENT_0 + offset); | |
431 | default: | |
432 | return -EINVAL; | |
433 | } | |
434 | /* ELM SYNDROME_VALID bit in SYNDROME_FRAGMENT_6[] needs | |
435 | * to be saved for all BCH schemes*/ | |
436 | regs->elm_syndrome_fragment_6[i] = elm_read_reg(info, | |
437 | ELM_SYNDROME_FRAGMENT_6 + offset); | |
438 | } | |
439 | return 0; | |
440 | } | |
441 | ||
442 | /** | |
443 | * elm_context_restore | |
444 | * writes configurations saved duing power-down back into ELM registers | |
445 | */ | |
446 | static int elm_context_restore(struct elm_info *info) | |
447 | { | |
448 | struct elm_registers *regs = &info->elm_regs; | |
449 | enum bch_ecc bch_type = info->bch_type; | |
450 | u32 offset = 0, i; | |
451 | ||
452 | elm_write_reg(info, ELM_IRQENABLE, regs->elm_irqenable); | |
453 | elm_write_reg(info, ELM_SYSCONFIG, regs->elm_sysconfig); | |
454 | elm_write_reg(info, ELM_LOCATION_CONFIG, regs->elm_location_config); | |
455 | elm_write_reg(info, ELM_PAGE_CTRL, regs->elm_page_ctrl); | |
456 | for (i = 0; i < ERROR_VECTOR_MAX; i++) { | |
457 | offset = i * SYNDROME_FRAGMENT_REG_SIZE; | |
458 | switch (bch_type) { | |
459 | case BCH8_ECC: | |
460 | elm_write_reg(info, ELM_SYNDROME_FRAGMENT_3 + offset, | |
461 | regs->elm_syndrome_fragment_3[i]); | |
462 | elm_write_reg(info, ELM_SYNDROME_FRAGMENT_2 + offset, | |
463 | regs->elm_syndrome_fragment_2[i]); | |
464 | case BCH4_ECC: | |
465 | elm_write_reg(info, ELM_SYNDROME_FRAGMENT_1 + offset, | |
466 | regs->elm_syndrome_fragment_1[i]); | |
467 | elm_write_reg(info, ELM_SYNDROME_FRAGMENT_0 + offset, | |
468 | regs->elm_syndrome_fragment_0[i]); | |
469 | default: | |
470 | return -EINVAL; | |
471 | } | |
472 | /* ELM_SYNDROME_VALID bit to be set in last to trigger FSM */ | |
473 | elm_write_reg(info, ELM_SYNDROME_FRAGMENT_6 + offset, | |
474 | regs->elm_syndrome_fragment_6[i] & | |
475 | ELM_SYNDROME_VALID); | |
476 | } | |
477 | return 0; | |
478 | } | |
479 | ||
480 | static int elm_suspend(struct device *dev) | |
481 | { | |
482 | struct elm_info *info = dev_get_drvdata(dev); | |
483 | elm_context_save(info); | |
484 | pm_runtime_put_sync(dev); | |
485 | return 0; | |
486 | } | |
487 | ||
488 | static int elm_resume(struct device *dev) | |
489 | { | |
490 | struct elm_info *info = dev_get_drvdata(dev); | |
491 | pm_runtime_get_sync(dev); | |
492 | elm_context_restore(info); | |
493 | return 0; | |
494 | } | |
495 | ||
496 | static SIMPLE_DEV_PM_OPS(elm_pm_ops, elm_suspend, elm_resume); | |
497 | ||
bf224335 PA |
498 | #ifdef CONFIG_OF |
499 | static const struct of_device_id elm_of_match[] = { | |
c80e572c | 500 | { .compatible = "ti,am3352-elm" }, |
bf224335 PA |
501 | {}, |
502 | }; | |
503 | MODULE_DEVICE_TABLE(of, elm_of_match); | |
504 | #endif | |
505 | ||
506 | static struct platform_driver elm_driver = { | |
507 | .driver = { | |
508 | .name = "elm", | |
509 | .owner = THIS_MODULE, | |
510 | .of_match_table = of_match_ptr(elm_of_match), | |
11f164d1 | 511 | .pm = &elm_pm_ops, |
bf224335 PA |
512 | }, |
513 | .probe = elm_probe, | |
514 | .remove = elm_remove, | |
515 | }; | |
516 | ||
517 | module_platform_driver(elm_driver); | |
518 | ||
519 | MODULE_DESCRIPTION("ELM driver for BCH error correction"); | |
520 | MODULE_AUTHOR("Texas Instruments"); | |
521 | MODULE_ALIAS("platform: elm"); | |
522 | MODULE_LICENSE("GPL v2"); |