summaryrefslogtreecommitdiff
path: root/arch/sh/drivers/platform_early.c
blob: 143747c45206fe6fd5e78cf57148127a9133c0ee (plain)
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
// SPDX--License-Identifier: GPL-2.0

#include <asm/platform_early.h>
#include <linux/mod_devicetable.h>
#include <linux/pm.h>

static __initdata LIST_HEAD(sh_early_platform_driver_list);
static __initdata LIST_HEAD(sh_early_platform_device_list);

static const struct platform_device_id *
platform_match_id(const struct platform_device_id *id,
		  struct platform_device *pdev)
{
	while (id->name[0]) {
		if (strcmp(pdev->name, id->name) == 0) {
			pdev->id_entry = id;
			return id;
		}
		id++;
	}
	return NULL;
}

static int platform_match(struct device *dev, struct device_driver *drv)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct platform_driver *pdrv = to_platform_driver(drv);

	/* When driver_override is set, only bind to the matching driver */
	if (pdev->driver_override)
		return !strcmp(pdev->driver_override, drv->name);

	/* Then try to match against the id table */
	if (pdrv->id_table)
		return platform_match_id(pdrv->id_table, pdev) != NULL;

	/* fall-back to driver name match */
	return (strcmp(pdev->name, drv->name) == 0);
}

#ifdef CONFIG_PM
static void device_pm_init_common(struct device *dev)
{
	if (!dev->power.early_init) {
		spin_lock_init(&dev->power.lock);
		dev->power.qos = NULL;
		dev->power.early_init = true;
	}
}

static void pm_runtime_early_init(struct device *dev)
{
	dev->power.disable_depth = 1;
	device_pm_init_common(dev);
}
#else
static void pm_runtime_early_init(struct device *dev) {}
#endif

/**
 * sh_early_platform_driver_register - register early platform driver
 * @epdrv: sh_early_platform driver structure
 * @buf: string passed from early_param()
 *
 * Helper function for sh_early_platform_init() / sh_early_platform_init_buffer()
 */
int __init sh_early_platform_driver_register(struct sh_early_platform_driver *epdrv,
					  char *buf)
{
	char *tmp;
	int n;

	/* Simply add the driver to the end of the global list.
	 * Drivers will by default be put on the list in compiled-in order.
	 */
	if (!epdrv->list.next) {
		INIT_LIST_HEAD(&epdrv->list);
		list_add_tail(&epdrv->list, &sh_early_platform_driver_list);
	}

	/* If the user has specified device then make sure the driver
	 * gets prioritized. The driver of the last device specified on
	 * command line will be put first on the list.
	 */
	n = strlen(epdrv->pdrv->driver.name);
	if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
		list_move(&epdrv->list, &sh_early_platform_driver_list);

		/* Allow passing parameters after device name */
		if (buf[n] == '\0' || buf[n] == ',')
			epdrv->requested_id = -1;
		else {
			epdrv->requested_id = simple_strtoul(&buf[n + 1],
							     &tmp, 10);

			if (buf[n] != '.' || (tmp == &buf[n + 1])) {
				epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
				n = 0;
			} else
				n += strcspn(&buf[n + 1], ",") + 1;
		}

		if (buf[n] == ',')
			n++;

		if (epdrv->bufsize) {
			memcpy(epdrv->buffer, &buf[n],
			       min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1));
			epdrv->buffer[epdrv->bufsize - 1] = '\0';
		}
	}

	return 0;
}

/**
 * sh_early_platform_add_devices - adds a number of early platform devices
 * @devs: array of early platform devices to add
 * @num: number of early platform devices in array
 *
 * Used by early architecture code to register early platform devices and
 * their platform data.
 */
void __init sh_early_platform_add_devices(struct platform_device **devs, int num)
{
	struct device *dev;
	int i;

	/* simply add the devices to list */
	for (i = 0; i < num; i++) {
		dev = &devs[i]->dev;

		if (!dev->devres_head.next) {
			pm_runtime_early_init(dev);
			INIT_LIST_HEAD(&dev->devres_head);
			list_add_tail(&dev->devres_head,
				      &sh_early_platform_device_list);
		}
	}
}

/**
 * sh_early_platform_driver_register_all - register early platform drivers
 * @class_str: string to identify early platform driver class
 *
 * Used by architecture code to register all early platform drivers
 * for a certain class. If omitted then only early platform drivers
 * with matching kernel command line class parameters will be registered.
 */
void __init sh_early_platform_driver_register_all(char *class_str)
{
	/* The "class_str" parameter may or may not be present on the kernel
	 * command line. If it is present then there may be more than one
	 * matching parameter.
	 *
	 * Since we register our early platform drivers using early_param()
	 * we need to make sure that they also get registered in the case
	 * when the parameter is missing from the kernel command line.
	 *
	 * We use parse_early_options() to make sure the early_param() gets
	 * called at least once. The early_param() may be called more than
	 * once since the name of the preferred device may be specified on
	 * the kernel command line. sh_early_platform_driver_register() handles
	 * this case for us.
	 */
	parse_early_options(class_str);
}

/**
 * sh_early_platform_match - find early platform device matching driver
 * @epdrv: early platform driver structure
 * @id: id to match against
 */
static struct platform_device * __init
sh_early_platform_match(struct sh_early_platform_driver *epdrv, int id)
{
	struct platform_device *pd;

	list_for_each_entry(pd, &sh_early_platform_device_list, dev.devres_head)
		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
			if (pd->id == id)
				return pd;

	return NULL;
}

/**
 * sh_early_platform_left - check if early platform driver has matching devices
 * @epdrv: early platform driver structure
 * @id: return true if id or above exists
 */
static int __init sh_early_platform_left(struct sh_early_platform_driver *epdrv,
				       int id)
{
	struct platform_device *pd;

	list_for_each_entry(pd, &sh_early_platform_device_list, dev.devres_head)
		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
			if (pd->id >= id)
				return 1;

	return 0;
}

/**
 * sh_early_platform_driver_probe_id - probe drivers matching class_str and id
 * @class_str: string to identify early platform driver class
 * @id: id to match against
 * @nr_probe: number of platform devices to successfully probe before exiting
 */
static int __init sh_early_platform_driver_probe_id(char *class_str,
						 int id,
						 int nr_probe)
{
	struct sh_early_platform_driver *epdrv;
	struct platform_device *match;
	int match_id;
	int n = 0;
	int left = 0;

	list_for_each_entry(epdrv, &sh_early_platform_driver_list, list) {
		/* only use drivers matching our class_str */
		if (strcmp(class_str, epdrv->class_str))
			continue;

		if (id == -2) {
			match_id = epdrv->requested_id;
			left = 1;

		} else {
			match_id = id;
			left += sh_early_platform_left(epdrv, id);

			/* skip requested id */
			switch (epdrv->requested_id) {
			case EARLY_PLATFORM_ID_ERROR:
			case EARLY_PLATFORM_ID_UNSET:
				break;
			default:
				if (epdrv->requested_id == id)
					match_id = EARLY_PLATFORM_ID_UNSET;
			}
		}

		switch (match_id) {
		case EARLY_PLATFORM_ID_ERROR:
			pr_warn("%s: unable to parse %s parameter\n",
				class_str, epdrv->pdrv->driver.name);
			fallthrough;
		case EARLY_PLATFORM_ID_UNSET:
			match = NULL;
			break;
		default:
			match = sh_early_platform_match(epdrv, match_id);
		}

		if (match) {
			/*
			 * Set up a sensible init_name to enable
			 * dev_name() and others to be used before the
			 * rest of the driver core is initialized.
			 */
			if (!match->dev.init_name && slab_is_available()) {
				if (match->id != -1)
					match->dev.init_name =
						kasprintf(GFP_KERNEL, "%s.%d",
							  match->name,
							  match->id);
				else
					match->dev.init_name =
						kasprintf(GFP_KERNEL, "%s",
							  match->name);

				if (!match->dev.init_name)
					return -ENOMEM;
			}

			if (epdrv->pdrv->probe(match))
				pr_warn("%s: unable to probe %s early.\n",
					class_str, match->name);
			else
				n++;
		}

		if (n >= nr_probe)
			break;
	}

	if (left)
		return n;
	else
		return -ENODEV;
}

/**
 * sh_early_platform_driver_probe - probe a class of registered drivers
 * @class_str: string to identify early platform driver class
 * @nr_probe: number of platform devices to successfully probe before exiting
 * @user_only: only probe user specified early platform devices
 *
 * Used by architecture code to probe registered early platform drivers
 * within a certain class. For probe to happen a registered early platform
 * device matching a registered early platform driver is needed.
 */
int __init sh_early_platform_driver_probe(char *class_str,
				       int nr_probe,
				       int user_only)
{
	int k, n, i;

	n = 0;
	for (i = -2; n < nr_probe; i++) {
		k = sh_early_platform_driver_probe_id(class_str, i, nr_probe - n);

		if (k < 0)
			break;

		n += k;

		if (user_only)
			break;
	}

	return n;
}

/**
 * early_platform_cleanup - clean up early platform code
 */
void __init early_platform_cleanup(void)
{
	struct platform_device *pd, *pd2;

	/* clean up the devres list used to chain devices */
	list_for_each_entry_safe(pd, pd2, &sh_early_platform_device_list,
				 dev.devres_head) {
		list_del(&pd->dev.devres_head);
		memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));
	}
}