Linux debugging

Check our new training course

Linux debugging, tracing, profiling & perf. analysis

Check our new training course
with Creative Commons CC-BY-SA
lecture and lab materials

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/drivers/mmc/core/host.c
 *
 *  Copyright (C) 2003 Russell King, All Rights Reserved.
 *  Copyright (C) 2007-2008 Pierre Ossman
 *  Copyright (C) 2010 Linus Walleij
 *
 *  MMC host class device management
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/idr.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/pagemap.h>
#include <linux/export.h>
#include <linux/leds.h>
#include <linux/slab.h>

#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/slot-gpio.h>

#include "core.h"
#include "host.h"
#include "slot-gpio.h"
#include "pwrseq.h"
#include "sdio_ops.h"

#define cls_dev_to_mmc_host(d)	container_of(d, struct mmc_host, class_dev)

static DEFINE_IDA(mmc_host_ida);

static void mmc_host_classdev_release(struct device *dev)
{
	struct mmc_host *host = cls_dev_to_mmc_host(dev);
	ida_simple_remove(&mmc_host_ida, host->index);
	kfree(host);
}

static struct class mmc_host_class = {
	.name		= "mmc_host",
	.dev_release	= mmc_host_classdev_release,
};

int mmc_register_host_class(void)
{
	return class_register(&mmc_host_class);
}

void mmc_unregister_host_class(void)
{
	class_unregister(&mmc_host_class);
}

void mmc_retune_enable(struct mmc_host *host)
{
	host->can_retune = 1;
	if (host->retune_period)
		mod_timer(&host->retune_timer,
			  jiffies + host->retune_period * HZ);
}

/*
 * Pause re-tuning for a small set of operations.  The pause begins after the
 * next command and after first doing re-tuning.
 */
void mmc_retune_pause(struct mmc_host *host)
{
	if (!host->retune_paused) {
		host->retune_paused = 1;
		mmc_retune_needed(host);
		mmc_retune_hold(host);
	}
}
EXPORT_SYMBOL(mmc_retune_pause);

void mmc_retune_unpause(struct mmc_host *host)
{
	if (host->retune_paused) {
		host->retune_paused = 0;
		mmc_retune_release(host);
	}
}
EXPORT_SYMBOL(mmc_retune_unpause);

void mmc_retune_disable(struct mmc_host *host)
{
	mmc_retune_unpause(host);
	host->can_retune = 0;
	del_timer_sync(&host->retune_timer);
	host->retune_now = 0;
	host->need_retune = 0;
}

void mmc_retune_timer_stop(struct mmc_host *host)
{
	del_timer_sync(&host->retune_timer);
}
EXPORT_SYMBOL(mmc_retune_timer_stop);

void mmc_retune_hold(struct mmc_host *host)
{
	if (!host->hold_retune)
		host->retune_now = 1;
	host->hold_retune += 1;
}

void mmc_retune_release(struct mmc_host *host)
{
	if (host->hold_retune)
		host->hold_retune -= 1;
	else
		WARN_ON(1);
}
EXPORT_SYMBOL(mmc_retune_release);

int mmc_retune(struct mmc_host *host)
{
	bool return_to_hs400 = false;
	int err;

	if (host->retune_now)
		host->retune_now = 0;
	else
		return 0;

	if (!host->need_retune || host->doing_retune || !host->card)
		return 0;

	host->need_retune = 0;

	host->doing_retune = 1;

	if (host->ios.timing == MMC_TIMING_MMC_HS400) {
		err = mmc_hs400_to_hs200(host->card);
		if (err)
			goto out;

		return_to_hs400 = true;
	}

	err = mmc_execute_tuning(host->card);
	if (err)
		goto out;

	if (return_to_hs400)
		err = mmc_hs200_to_hs400(host->card);
out:
	host->doing_retune = 0;

	return err;
}

static void mmc_retune_timer(struct timer_list *t)
{
	struct mmc_host *host = from_timer(host, t, retune_timer);

	mmc_retune_needed(host);
}

/**
 *	mmc_of_parse() - parse host's device-tree node
 *	@host: host whose node should be parsed.
 *
 * To keep the rest of the MMC subsystem unaware of whether DT has been
 * used to to instantiate and configure this host instance or not, we
 * parse the properties and set respective generic mmc-host flags and
 * parameters.
 */
int mmc_of_parse(struct mmc_host *host)
{
	struct device *dev = host->parent;
	u32 bus_width, drv_type, cd_debounce_delay_ms;
	int ret;
	bool cd_cap_invert, cd_gpio_invert = false;
	bool ro_cap_invert, ro_gpio_invert = false;

	if (!dev || !dev_fwnode(dev))
		return 0;

	/* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
	if (device_property_read_u32(dev, "bus-width", &bus_width) < 0) {
		dev_dbg(host->parent,
			"\"bus-width\" property is missing, assuming 1 bit.\n");
		bus_width = 1;
	}

	switch (bus_width) {
	case 8:
		host->caps |= MMC_CAP_8_BIT_DATA;
		/* fall through - Hosts capable of 8-bit can also do 4 bits */
	case 4:
		host->caps |= MMC_CAP_4_BIT_DATA;
		break;
	case 1:
		break;
	default:
		dev_err(host->parent,
			"Invalid \"bus-width\" value %u!\n", bus_width);
		return -EINVAL;
	}

	/* f_max is obtained from the optional "max-frequency" property */
	device_property_read_u32(dev, "max-frequency", &host->f_max);

	/*
	 * Configure CD and WP pins. They are both by default active low to
	 * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
	 * mmc-gpio helpers are used to attach, configure and use them. If
	 * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
	 * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
	 * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
	 * is set. If the "non-removable" property is found, the
	 * MMC_CAP_NONREMOVABLE capability is set and no card-detection
	 * configuration is performed.
	 */

	/* Parse Card Detection */
	if (device_property_read_bool(dev, "non-removable")) {
		host->caps |= MMC_CAP_NONREMOVABLE;
	} else {
		cd_cap_invert = device_property_read_bool(dev, "cd-inverted");

		if (device_property_read_u32(dev, "cd-debounce-delay-ms",
					     &cd_debounce_delay_ms))
			cd_debounce_delay_ms = 200;

		if (device_property_read_bool(dev, "broken-cd"))
			host->caps |= MMC_CAP_NEEDS_POLL;

		ret = mmc_gpiod_request_cd(host, "cd", 0, false,
					   cd_debounce_delay_ms * 1000,
					   &cd_gpio_invert);
		if (!ret)
			dev_info(host->parent, "Got CD GPIO\n");
		else if (ret != -ENOENT && ret != -ENOSYS)
			return ret;

		/*
		 * There are two ways to flag that the CD line is inverted:
		 * through the cd-inverted flag and by the GPIO line itself
		 * being inverted from the GPIO subsystem. This is a leftover
		 * from the times when the GPIO subsystem did not make it
		 * possible to flag a line as inverted.
		 *
		 * If the capability on the host AND the GPIO line are
		 * both inverted, the end result is that the CD line is
		 * not inverted.
		 */
		if (cd_cap_invert ^ cd_gpio_invert)
			host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
	}

	/* Parse Write Protection */
	ro_cap_invert = device_property_read_bool(dev, "wp-inverted");

	ret = mmc_gpiod_request_ro(host, "wp", 0, 0, &ro_gpio_invert);
	if (!ret)
		dev_info(host->parent, "Got WP GPIO\n");
	else if (ret != -ENOENT && ret != -ENOSYS)
		return ret;

	if (device_property_read_bool(dev, "disable-wp"))
		host->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;

	/* See the comment on CD inversion above */
	if (ro_cap_invert ^ ro_gpio_invert)
		host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;

	if (device_property_read_bool(dev, "cap-sd-highspeed"))
		host->caps |= MMC_CAP_SD_HIGHSPEED;
	if (device_property_read_bool(dev, "cap-mmc-highspeed"))
		host->caps |= MMC_CAP_MMC_HIGHSPEED;
	if (device_property_read_bool(dev, "sd-uhs-sdr12"))
		host->caps |= MMC_CAP_UHS_SDR12;
	if (device_property_read_bool(dev, "sd-uhs-sdr25"))
		host->caps |= MMC_CAP_UHS_SDR25;
	if (device_property_read_bool(dev, "sd-uhs-sdr50"))
		host->caps |= MMC_CAP_UHS_SDR50;
	if (device_property_read_bool(dev, "sd-uhs-sdr104"))
		host->caps |= MMC_CAP_UHS_SDR104;
	if (device_property_read_bool(dev, "sd-uhs-ddr50"))
		host->caps |= MMC_CAP_UHS_DDR50;
	if (device_property_read_bool(dev, "cap-power-off-card"))
		host->caps |= MMC_CAP_POWER_OFF_CARD;
	if (device_property_read_bool(dev, "cap-mmc-hw-reset"))
		host->caps |= MMC_CAP_HW_RESET;
	if (device_property_read_bool(dev, "cap-sdio-irq"))
		host->caps |= MMC_CAP_SDIO_IRQ;
	if (device_property_read_bool(dev, "full-pwr-cycle"))
		host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
	if (device_property_read_bool(dev, "keep-power-in-suspend"))
		host->pm_caps |= MMC_PM_KEEP_POWER;
	if (device_property_read_bool(dev, "wakeup-source") ||
	    device_property_read_bool(dev, "enable-sdio-wakeup")) /* legacy */
		host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
	if (device_property_read_bool(dev, "mmc-ddr-3_3v"))
		host->caps |= MMC_CAP_3_3V_DDR;
	if (device_property_read_bool(dev, "mmc-ddr-1_8v"))
		host->caps |= MMC_CAP_1_8V_DDR;
	if (device_property_read_bool(dev, "mmc-ddr-1_2v"))
		host->caps |= MMC_CAP_1_2V_DDR;
	if (device_property_read_bool(dev, "mmc-hs200-1_8v"))
		host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
	if (device_property_read_bool(dev, "mmc-hs200-1_2v"))
		host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
	if (device_property_read_bool(dev, "mmc-hs400-1_8v"))
		host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
	if (device_property_read_bool(dev, "mmc-hs400-1_2v"))
		host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
	if (device_property_read_bool(dev, "mmc-hs400-enhanced-strobe"))
		host->caps2 |= MMC_CAP2_HS400_ES;
	if (device_property_read_bool(dev, "no-sdio"))
		host->caps2 |= MMC_CAP2_NO_SDIO;
	if (device_property_read_bool(dev, "no-sd"))
		host->caps2 |= MMC_CAP2_NO_SD;
	if (device_property_read_bool(dev, "no-mmc"))
		host->caps2 |= MMC_CAP2_NO_MMC;

	/* Must be after "non-removable" check */
	if (device_property_read_u32(dev, "fixed-emmc-driver-type", &drv_type) == 0) {
		if (host->caps & MMC_CAP_NONREMOVABLE)
			host->fixed_drv_type = drv_type;
		else
			dev_err(host->parent,
				"can't use fixed driver type, media is removable\n");
	}

	host->dsr_req = !device_property_read_u32(dev, "dsr", &host->dsr);
	if (host->dsr_req && (host->dsr & ~0xffff)) {
		dev_err(host->parent,
			"device tree specified broken value for DSR: 0x%x, ignoring\n",
			host->dsr);
		host->dsr_req = 0;
	}

	device_property_read_u32(dev, "post-power-on-delay-ms",
				 &host->ios.power_delay_ms);

	return mmc_pwrseq_alloc(host);
}

EXPORT_SYMBOL(mmc_of_parse);

/**
 * mmc_of_parse_voltage - return mask of supported voltages
 * @np: The device node need to be parsed.
 * @mask: mask of voltages available for MMC/SD/SDIO
 *
 * Parse the "voltage-ranges" DT property, returning zero if it is not
 * found, negative errno if the voltage-range specification is invalid,
 * or one if the voltage-range is specified and successfully parsed.
 */
int mmc_of_parse_voltage(struct device_node *np, u32 *mask)
{
	const u32 *voltage_ranges;
	int num_ranges, i;

	voltage_ranges = of_get_property(np, "voltage-ranges", &num_ranges);
	if (!voltage_ranges) {
		pr_debug("%pOF: voltage-ranges unspecified\n", np);
		return 0;
	}
	num_ranges = num_ranges / sizeof(*voltage_ranges) / 2;
	if (!num_ranges) {
		pr_err("%pOF: voltage-ranges empty\n", np);
		return -EINVAL;
	}

	for (i = 0; i < num_ranges; i++) {
		const int j = i * 2;
		u32 ocr_mask;

		ocr_mask = mmc_vddrange_to_ocrmask(
				be32_to_cpu(voltage_ranges[j]),
				be32_to_cpu(voltage_ranges[j + 1]));
		if (!ocr_mask) {
			pr_err("%pOF: voltage-range #%d is invalid\n",
				np, i);
			return -EINVAL;
		}
		*mask |= ocr_mask;
	}

	return 1;
}
EXPORT_SYMBOL(mmc_of_parse_voltage);

/**
 *	mmc_alloc_host - initialise the per-host structure.
 *	@extra: sizeof private data structure
 *	@dev: pointer to host device model structure
 *
 *	Initialise the per-host structure.
 */
struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
{
	int err;
	struct mmc_host *host;

	host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
	if (!host)
		return NULL;

	/* scanning will be enabled when we're ready */
	host->rescan_disable = 1;

	err = ida_simple_get(&mmc_host_ida, 0, 0, GFP_KERNEL);
	if (err < 0) {
		kfree(host);
		return NULL;
	}

	host->index = err;

	dev_set_name(&host->class_dev, "mmc%d", host->index);

	host->parent = dev;
	host->class_dev.parent = dev;
	host->class_dev.class = &mmc_host_class;
	device_initialize(&host->class_dev);
	device_enable_async_suspend(&host->class_dev);

	if (mmc_gpio_alloc(host)) {
		put_device(&host->class_dev);
		return NULL;
	}

	spin_lock_init(&host->lock);
	init_waitqueue_head(&host->wq);
	INIT_DELAYED_WORK(&host->detect, mmc_rescan);
	INIT_DELAYED_WORK(&host->sdio_irq_work, sdio_irq_work);
	timer_setup(&host->retune_timer, mmc_retune_timer, 0);

	/*
	 * By default, hosts do not support SGIO or large requests.
	 * They have to set these according to their abilities.
	 */
	host->max_segs = 1;
	host->max_seg_size = PAGE_SIZE;

	host->max_req_size = PAGE_SIZE;
	host->max_blk_size = 512;
	host->max_blk_count = PAGE_SIZE / 512;

	host->fixed_drv_type = -EINVAL;
	host->ios.power_delay_ms = 10;

	return host;
}

EXPORT_SYMBOL(mmc_alloc_host);

/**
 *	mmc_add_host - initialise host hardware
 *	@host: mmc host
 *
 *	Register the host with the driver model. The host must be
 *	prepared to start servicing requests before this function
 *	completes.
 */
int mmc_add_host(struct mmc_host *host)
{
	int err;

	WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
		!host->ops->enable_sdio_irq);

	err = device_add(&host->class_dev);
	if (err)
		return err;

	led_trigger_register_simple(dev_name(&host->class_dev), &host->led);

#ifdef CONFIG_DEBUG_FS
	mmc_add_host_debugfs(host);
#endif

	mmc_start_host(host);
	mmc_register_pm_notifier(host);

	return 0;
}

EXPORT_SYMBOL(mmc_add_host);

/**
 *	mmc_remove_host - remove host hardware
 *	@host: mmc host
 *
 *	Unregister and remove all cards associated with this host,
 *	and power down the MMC bus. No new requests will be issued
 *	after this function has returned.
 */
void mmc_remove_host(struct mmc_host *host)
{
	mmc_unregister_pm_notifier(host);
	mmc_stop_host(host);

#ifdef CONFIG_DEBUG_FS
	mmc_remove_host_debugfs(host);
#endif

	device_del(&host->class_dev);

	led_trigger_unregister_simple(host->led);
}

EXPORT_SYMBOL(mmc_remove_host);

/**
 *	mmc_free_host - free the host structure
 *	@host: mmc host
 *
 *	Free the host once all references to it have been dropped.
 */
void mmc_free_host(struct mmc_host *host)
{
	mmc_pwrseq_free(host);
	put_device(&host->class_dev);
}

EXPORT_SYMBOL(mmc_free_host);