mtd: omap_elm: Fix module alias
[linux-2.6/btrfs-unstable.git] / drivers / mtd / nand / omap_elm.c
blob235ec7992b4cf16ce59bfa4ae9b57dc0d6470ea4
1 /*
2 * Error Location Module
4 * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
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.
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.
18 #define DRIVER_NAME "omap-elm"
20 #include <linux/platform_device.h>
21 #include <linux/module.h>
22 #include <linux/interrupt.h>
23 #include <linux/io.h>
24 #include <linux/of.h>
25 #include <linux/sched.h>
26 #include <linux/pm_runtime.h>
27 #include <linux/platform_data/elm.h>
29 #define ELM_SYSCONFIG 0x010
30 #define ELM_IRQSTATUS 0x018
31 #define ELM_IRQENABLE 0x01c
32 #define ELM_LOCATION_CONFIG 0x020
33 #define ELM_PAGE_CTRL 0x080
34 #define ELM_SYNDROME_FRAGMENT_0 0x400
35 #define ELM_SYNDROME_FRAGMENT_1 0x404
36 #define ELM_SYNDROME_FRAGMENT_2 0x408
37 #define ELM_SYNDROME_FRAGMENT_3 0x40c
38 #define ELM_SYNDROME_FRAGMENT_4 0x410
39 #define ELM_SYNDROME_FRAGMENT_5 0x414
40 #define ELM_SYNDROME_FRAGMENT_6 0x418
41 #define ELM_LOCATION_STATUS 0x800
42 #define ELM_ERROR_LOCATION_0 0x880
44 /* ELM Interrupt Status Register */
45 #define INTR_STATUS_PAGE_VALID BIT(8)
47 /* ELM Interrupt Enable Register */
48 #define INTR_EN_PAGE_MASK BIT(8)
50 /* ELM Location Configuration Register */
51 #define ECC_BCH_LEVEL_MASK 0x3
53 /* ELM syndrome */
54 #define ELM_SYNDROME_VALID BIT(16)
56 /* ELM_LOCATION_STATUS Register */
57 #define ECC_CORRECTABLE_MASK BIT(8)
58 #define ECC_NB_ERRORS_MASK 0x1f
60 /* ELM_ERROR_LOCATION_0-15 Registers */
61 #define ECC_ERROR_LOCATION_MASK 0x1fff
63 #define ELM_ECC_SIZE 0x7ff
65 #define SYNDROME_FRAGMENT_REG_SIZE 0x40
66 #define ERROR_LOCATION_SIZE 0x100
68 struct elm_registers {
69 u32 elm_irqenable;
70 u32 elm_sysconfig;
71 u32 elm_location_config;
72 u32 elm_page_ctrl;
73 u32 elm_syndrome_fragment_6[ERROR_VECTOR_MAX];
74 u32 elm_syndrome_fragment_5[ERROR_VECTOR_MAX];
75 u32 elm_syndrome_fragment_4[ERROR_VECTOR_MAX];
76 u32 elm_syndrome_fragment_3[ERROR_VECTOR_MAX];
77 u32 elm_syndrome_fragment_2[ERROR_VECTOR_MAX];
78 u32 elm_syndrome_fragment_1[ERROR_VECTOR_MAX];
79 u32 elm_syndrome_fragment_0[ERROR_VECTOR_MAX];
82 struct elm_info {
83 struct device *dev;
84 void __iomem *elm_base;
85 struct completion elm_completion;
86 struct list_head list;
87 enum bch_ecc bch_type;
88 struct elm_registers elm_regs;
89 int ecc_steps;
90 int ecc_syndrome_size;
93 static LIST_HEAD(elm_devices);
95 static void elm_write_reg(struct elm_info *info, int offset, u32 val)
97 writel(val, info->elm_base + offset);
100 static u32 elm_read_reg(struct elm_info *info, int offset)
102 return readl(info->elm_base + offset);
106 * elm_config - Configure ELM module
107 * @dev: ELM device
108 * @bch_type: Type of BCH ecc
110 int elm_config(struct device *dev, enum bch_ecc bch_type,
111 int ecc_steps, int ecc_step_size, int ecc_syndrome_size)
113 u32 reg_val;
114 struct elm_info *info = dev_get_drvdata(dev);
116 if (!info) {
117 dev_err(dev, "Unable to configure elm - device not probed?\n");
118 return -EPROBE_DEFER;
120 /* ELM cannot detect ECC errors for chunks > 1KB */
121 if (ecc_step_size > ((ELM_ECC_SIZE + 1) / 2)) {
122 dev_err(dev, "unsupported config ecc-size=%d\n", ecc_step_size);
123 return -EINVAL;
125 /* ELM support 8 error syndrome process */
126 if (ecc_steps > ERROR_VECTOR_MAX) {
127 dev_err(dev, "unsupported config ecc-step=%d\n", ecc_steps);
128 return -EINVAL;
131 reg_val = (bch_type & ECC_BCH_LEVEL_MASK) | (ELM_ECC_SIZE << 16);
132 elm_write_reg(info, ELM_LOCATION_CONFIG, reg_val);
133 info->bch_type = bch_type;
134 info->ecc_steps = ecc_steps;
135 info->ecc_syndrome_size = ecc_syndrome_size;
137 return 0;
139 EXPORT_SYMBOL(elm_config);
142 * elm_configure_page_mode - Enable/Disable page mode
143 * @info: elm info
144 * @index: index number of syndrome fragment vector
145 * @enable: enable/disable flag for page mode
147 * Enable page mode for syndrome fragment index
149 static void elm_configure_page_mode(struct elm_info *info, int index,
150 bool enable)
152 u32 reg_val;
154 reg_val = elm_read_reg(info, ELM_PAGE_CTRL);
155 if (enable)
156 reg_val |= BIT(index); /* enable page mode */
157 else
158 reg_val &= ~BIT(index); /* disable page mode */
160 elm_write_reg(info, ELM_PAGE_CTRL, reg_val);
164 * elm_load_syndrome - Load ELM syndrome reg
165 * @info: elm info
166 * @err_vec: elm error vectors
167 * @ecc: buffer with calculated ecc
169 * Load syndrome fragment registers with calculated ecc in reverse order.
171 static void elm_load_syndrome(struct elm_info *info,
172 struct elm_errorvec *err_vec, u8 *ecc)
174 int i, offset;
175 u32 val;
177 for (i = 0; i < info->ecc_steps; i++) {
179 /* Check error reported */
180 if (err_vec[i].error_reported) {
181 elm_configure_page_mode(info, i, true);
182 offset = ELM_SYNDROME_FRAGMENT_0 +
183 SYNDROME_FRAGMENT_REG_SIZE * i;
184 switch (info->bch_type) {
185 case BCH8_ECC:
186 /* syndrome fragment 0 = ecc[9-12B] */
187 val = cpu_to_be32(*(u32 *) &ecc[9]);
188 elm_write_reg(info, offset, val);
190 /* syndrome fragment 1 = ecc[5-8B] */
191 offset += 4;
192 val = cpu_to_be32(*(u32 *) &ecc[5]);
193 elm_write_reg(info, offset, val);
195 /* syndrome fragment 2 = ecc[1-4B] */
196 offset += 4;
197 val = cpu_to_be32(*(u32 *) &ecc[1]);
198 elm_write_reg(info, offset, val);
200 /* syndrome fragment 3 = ecc[0B] */
201 offset += 4;
202 val = ecc[0];
203 elm_write_reg(info, offset, val);
204 break;
205 case BCH4_ECC:
206 /* syndrome fragment 0 = ecc[20-52b] bits */
207 val = (cpu_to_be32(*(u32 *) &ecc[3]) >> 4) |
208 ((ecc[2] & 0xf) << 28);
209 elm_write_reg(info, offset, val);
211 /* syndrome fragment 1 = ecc[0-20b] bits */
212 offset += 4;
213 val = cpu_to_be32(*(u32 *) &ecc[0]) >> 12;
214 elm_write_reg(info, offset, val);
215 break;
216 case BCH16_ECC:
217 val = cpu_to_be32(*(u32 *) &ecc[22]);
218 elm_write_reg(info, offset, val);
219 offset += 4;
220 val = cpu_to_be32(*(u32 *) &ecc[18]);
221 elm_write_reg(info, offset, val);
222 offset += 4;
223 val = cpu_to_be32(*(u32 *) &ecc[14]);
224 elm_write_reg(info, offset, val);
225 offset += 4;
226 val = cpu_to_be32(*(u32 *) &ecc[10]);
227 elm_write_reg(info, offset, val);
228 offset += 4;
229 val = cpu_to_be32(*(u32 *) &ecc[6]);
230 elm_write_reg(info, offset, val);
231 offset += 4;
232 val = cpu_to_be32(*(u32 *) &ecc[2]);
233 elm_write_reg(info, offset, val);
234 offset += 4;
235 val = cpu_to_be32(*(u32 *) &ecc[0]) >> 16;
236 elm_write_reg(info, offset, val);
237 break;
238 default:
239 pr_err("invalid config bch_type\n");
243 /* Update ecc pointer with ecc byte size */
244 ecc += info->ecc_syndrome_size;
249 * elm_start_processing - start elm syndrome processing
250 * @info: elm info
251 * @err_vec: elm error vectors
253 * Set syndrome valid bit for syndrome fragment registers for which
254 * elm syndrome fragment registers are loaded. This enables elm module
255 * to start processing syndrome vectors.
257 static void elm_start_processing(struct elm_info *info,
258 struct elm_errorvec *err_vec)
260 int i, offset;
261 u32 reg_val;
264 * Set syndrome vector valid, so that ELM module
265 * will process it for vectors error is reported
267 for (i = 0; i < info->ecc_steps; i++) {
268 if (err_vec[i].error_reported) {
269 offset = ELM_SYNDROME_FRAGMENT_6 +
270 SYNDROME_FRAGMENT_REG_SIZE * i;
271 reg_val = elm_read_reg(info, offset);
272 reg_val |= ELM_SYNDROME_VALID;
273 elm_write_reg(info, offset, reg_val);
279 * elm_error_correction - locate correctable error position
280 * @info: elm info
281 * @err_vec: elm error vectors
283 * On completion of processing by elm module, error location status
284 * register updated with correctable/uncorrectable error information.
285 * In case of correctable errors, number of errors located from
286 * elm location status register & read the positions from
287 * elm error location register.
289 static void elm_error_correction(struct elm_info *info,
290 struct elm_errorvec *err_vec)
292 int i, j, errors = 0;
293 int offset;
294 u32 reg_val;
296 for (i = 0; i < info->ecc_steps; i++) {
298 /* Check error reported */
299 if (err_vec[i].error_reported) {
300 offset = ELM_LOCATION_STATUS + ERROR_LOCATION_SIZE * i;
301 reg_val = elm_read_reg(info, offset);
303 /* Check correctable error or not */
304 if (reg_val & ECC_CORRECTABLE_MASK) {
305 offset = ELM_ERROR_LOCATION_0 +
306 ERROR_LOCATION_SIZE * i;
308 /* Read count of correctable errors */
309 err_vec[i].error_count = reg_val &
310 ECC_NB_ERRORS_MASK;
312 /* Update the error locations in error vector */
313 for (j = 0; j < err_vec[i].error_count; j++) {
315 reg_val = elm_read_reg(info, offset);
316 err_vec[i].error_loc[j] = reg_val &
317 ECC_ERROR_LOCATION_MASK;
319 /* Update error location register */
320 offset += 4;
323 errors += err_vec[i].error_count;
324 } else {
325 err_vec[i].error_uncorrectable = true;
328 /* Clearing interrupts for processed error vectors */
329 elm_write_reg(info, ELM_IRQSTATUS, BIT(i));
331 /* Disable page mode */
332 elm_configure_page_mode(info, i, false);
338 * elm_decode_bch_error_page - Locate error position
339 * @dev: device pointer
340 * @ecc_calc: calculated ECC bytes from GPMC
341 * @err_vec: elm error vectors
343 * Called with one or more error reported vectors & vectors with
344 * error reported is updated in err_vec[].error_reported
346 void elm_decode_bch_error_page(struct device *dev, u8 *ecc_calc,
347 struct elm_errorvec *err_vec)
349 struct elm_info *info = dev_get_drvdata(dev);
350 u32 reg_val;
352 /* Enable page mode interrupt */
353 reg_val = elm_read_reg(info, ELM_IRQSTATUS);
354 elm_write_reg(info, ELM_IRQSTATUS, reg_val & INTR_STATUS_PAGE_VALID);
355 elm_write_reg(info, ELM_IRQENABLE, INTR_EN_PAGE_MASK);
357 /* Load valid ecc byte to syndrome fragment register */
358 elm_load_syndrome(info, err_vec, ecc_calc);
360 /* Enable syndrome processing for which syndrome fragment is updated */
361 elm_start_processing(info, err_vec);
363 /* Wait for ELM module to finish locating error correction */
364 wait_for_completion(&info->elm_completion);
366 /* Disable page mode interrupt */
367 reg_val = elm_read_reg(info, ELM_IRQENABLE);
368 elm_write_reg(info, ELM_IRQENABLE, reg_val & ~INTR_EN_PAGE_MASK);
369 elm_error_correction(info, err_vec);
371 EXPORT_SYMBOL(elm_decode_bch_error_page);
373 static irqreturn_t elm_isr(int this_irq, void *dev_id)
375 u32 reg_val;
376 struct elm_info *info = dev_id;
378 reg_val = elm_read_reg(info, ELM_IRQSTATUS);
380 /* All error vectors processed */
381 if (reg_val & INTR_STATUS_PAGE_VALID) {
382 elm_write_reg(info, ELM_IRQSTATUS,
383 reg_val & INTR_STATUS_PAGE_VALID);
384 complete(&info->elm_completion);
385 return IRQ_HANDLED;
388 return IRQ_NONE;
391 static int elm_probe(struct platform_device *pdev)
393 int ret = 0;
394 struct resource *res, *irq;
395 struct elm_info *info;
397 info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
398 if (!info)
399 return -ENOMEM;
401 info->dev = &pdev->dev;
403 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
404 if (!irq) {
405 dev_err(&pdev->dev, "no irq resource defined\n");
406 return -ENODEV;
409 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
410 info->elm_base = devm_ioremap_resource(&pdev->dev, res);
411 if (IS_ERR(info->elm_base))
412 return PTR_ERR(info->elm_base);
414 ret = devm_request_irq(&pdev->dev, irq->start, elm_isr, 0,
415 pdev->name, info);
416 if (ret) {
417 dev_err(&pdev->dev, "failure requesting irq %i\n", irq->start);
418 return ret;
421 pm_runtime_enable(&pdev->dev);
422 if (pm_runtime_get_sync(&pdev->dev) < 0) {
423 ret = -EINVAL;
424 pm_runtime_disable(&pdev->dev);
425 dev_err(&pdev->dev, "can't enable clock\n");
426 return ret;
429 init_completion(&info->elm_completion);
430 INIT_LIST_HEAD(&info->list);
431 list_add(&info->list, &elm_devices);
432 platform_set_drvdata(pdev, info);
433 return ret;
436 static int elm_remove(struct platform_device *pdev)
438 pm_runtime_put_sync(&pdev->dev);
439 pm_runtime_disable(&pdev->dev);
440 return 0;
443 #ifdef CONFIG_PM_SLEEP
445 * elm_context_save
446 * saves ELM configurations to preserve them across Hardware powered-down
448 static int elm_context_save(struct elm_info *info)
450 struct elm_registers *regs = &info->elm_regs;
451 enum bch_ecc bch_type = info->bch_type;
452 u32 offset = 0, i;
454 regs->elm_irqenable = elm_read_reg(info, ELM_IRQENABLE);
455 regs->elm_sysconfig = elm_read_reg(info, ELM_SYSCONFIG);
456 regs->elm_location_config = elm_read_reg(info, ELM_LOCATION_CONFIG);
457 regs->elm_page_ctrl = elm_read_reg(info, ELM_PAGE_CTRL);
458 for (i = 0; i < ERROR_VECTOR_MAX; i++) {
459 offset = i * SYNDROME_FRAGMENT_REG_SIZE;
460 switch (bch_type) {
461 case BCH16_ECC:
462 regs->elm_syndrome_fragment_6[i] = elm_read_reg(info,
463 ELM_SYNDROME_FRAGMENT_6 + offset);
464 regs->elm_syndrome_fragment_5[i] = elm_read_reg(info,
465 ELM_SYNDROME_FRAGMENT_5 + offset);
466 regs->elm_syndrome_fragment_4[i] = elm_read_reg(info,
467 ELM_SYNDROME_FRAGMENT_4 + offset);
468 case BCH8_ECC:
469 regs->elm_syndrome_fragment_3[i] = elm_read_reg(info,
470 ELM_SYNDROME_FRAGMENT_3 + offset);
471 regs->elm_syndrome_fragment_2[i] = elm_read_reg(info,
472 ELM_SYNDROME_FRAGMENT_2 + offset);
473 case BCH4_ECC:
474 regs->elm_syndrome_fragment_1[i] = elm_read_reg(info,
475 ELM_SYNDROME_FRAGMENT_1 + offset);
476 regs->elm_syndrome_fragment_0[i] = elm_read_reg(info,
477 ELM_SYNDROME_FRAGMENT_0 + offset);
478 break;
479 default:
480 return -EINVAL;
482 /* ELM SYNDROME_VALID bit in SYNDROME_FRAGMENT_6[] needs
483 * to be saved for all BCH schemes*/
484 regs->elm_syndrome_fragment_6[i] = elm_read_reg(info,
485 ELM_SYNDROME_FRAGMENT_6 + offset);
487 return 0;
491 * elm_context_restore
492 * writes configurations saved duing power-down back into ELM registers
494 static int elm_context_restore(struct elm_info *info)
496 struct elm_registers *regs = &info->elm_regs;
497 enum bch_ecc bch_type = info->bch_type;
498 u32 offset = 0, i;
500 elm_write_reg(info, ELM_IRQENABLE, regs->elm_irqenable);
501 elm_write_reg(info, ELM_SYSCONFIG, regs->elm_sysconfig);
502 elm_write_reg(info, ELM_LOCATION_CONFIG, regs->elm_location_config);
503 elm_write_reg(info, ELM_PAGE_CTRL, regs->elm_page_ctrl);
504 for (i = 0; i < ERROR_VECTOR_MAX; i++) {
505 offset = i * SYNDROME_FRAGMENT_REG_SIZE;
506 switch (bch_type) {
507 case BCH16_ECC:
508 elm_write_reg(info, ELM_SYNDROME_FRAGMENT_6 + offset,
509 regs->elm_syndrome_fragment_6[i]);
510 elm_write_reg(info, ELM_SYNDROME_FRAGMENT_5 + offset,
511 regs->elm_syndrome_fragment_5[i]);
512 elm_write_reg(info, ELM_SYNDROME_FRAGMENT_4 + offset,
513 regs->elm_syndrome_fragment_4[i]);
514 case BCH8_ECC:
515 elm_write_reg(info, ELM_SYNDROME_FRAGMENT_3 + offset,
516 regs->elm_syndrome_fragment_3[i]);
517 elm_write_reg(info, ELM_SYNDROME_FRAGMENT_2 + offset,
518 regs->elm_syndrome_fragment_2[i]);
519 case BCH4_ECC:
520 elm_write_reg(info, ELM_SYNDROME_FRAGMENT_1 + offset,
521 regs->elm_syndrome_fragment_1[i]);
522 elm_write_reg(info, ELM_SYNDROME_FRAGMENT_0 + offset,
523 regs->elm_syndrome_fragment_0[i]);
524 break;
525 default:
526 return -EINVAL;
528 /* ELM_SYNDROME_VALID bit to be set in last to trigger FSM */
529 elm_write_reg(info, ELM_SYNDROME_FRAGMENT_6 + offset,
530 regs->elm_syndrome_fragment_6[i] &
531 ELM_SYNDROME_VALID);
533 return 0;
536 static int elm_suspend(struct device *dev)
538 struct elm_info *info = dev_get_drvdata(dev);
539 elm_context_save(info);
540 pm_runtime_put_sync(dev);
541 return 0;
544 static int elm_resume(struct device *dev)
546 struct elm_info *info = dev_get_drvdata(dev);
547 pm_runtime_get_sync(dev);
548 elm_context_restore(info);
549 return 0;
551 #endif
553 static SIMPLE_DEV_PM_OPS(elm_pm_ops, elm_suspend, elm_resume);
555 #ifdef CONFIG_OF
556 static const struct of_device_id elm_of_match[] = {
557 { .compatible = "ti,am3352-elm" },
560 MODULE_DEVICE_TABLE(of, elm_of_match);
561 #endif
563 static struct platform_driver elm_driver = {
564 .driver = {
565 .name = DRIVER_NAME,
566 .of_match_table = of_match_ptr(elm_of_match),
567 .pm = &elm_pm_ops,
569 .probe = elm_probe,
570 .remove = elm_remove,
573 module_platform_driver(elm_driver);
575 MODULE_DESCRIPTION("ELM driver for BCH error correction");
576 MODULE_AUTHOR("Texas Instruments");
577 MODULE_ALIAS("platform:" DRIVER_NAME);
578 MODULE_LICENSE("GPL v2");