summaryrefslogtreecommitdiff
path: root/drivers/nvmem/sprd-efuse.c
blob: 59523245db8a54f1825acaba2386b91b50b8e244 (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
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
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2019 Spreadtrum Communications Inc.

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/hwspinlock.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/nvmem-provider.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>

#define SPRD_EFUSE_ENABLE		0x20
#define SPRD_EFUSE_ERR_FLAG		0x24
#define SPRD_EFUSE_ERR_CLR		0x28
#define SPRD_EFUSE_MAGIC_NUM		0x2c
#define SPRD_EFUSE_FW_CFG		0x50
#define SPRD_EFUSE_PW_SWT		0x54
#define SPRD_EFUSE_MEM(val)		(0x1000 + ((val) << 2))

#define SPRD_EFUSE_VDD_EN		BIT(0)
#define SPRD_EFUSE_AUTO_CHECK_EN	BIT(1)
#define SPRD_EFUSE_DOUBLE_EN		BIT(2)
#define SPRD_EFUSE_MARGIN_RD_EN		BIT(3)
#define SPRD_EFUSE_LOCK_WR_EN		BIT(4)

#define SPRD_EFUSE_ERR_CLR_MASK		GENMASK(13, 0)

#define SPRD_EFUSE_ENK1_ON		BIT(0)
#define SPRD_EFUSE_ENK2_ON		BIT(1)
#define SPRD_EFUSE_PROG_EN		BIT(2)

#define SPRD_EFUSE_MAGIC_NUMBER		0x8810

/* Block width (bytes) definitions */
#define SPRD_EFUSE_BLOCK_WIDTH		4

/*
 * The Spreadtrum AP efuse contains 2 parts: normal efuse and secure efuse,
 * and we can only access the normal efuse in kernel. So define the normal
 * block offset index and normal block numbers.
 */
#define SPRD_EFUSE_NORMAL_BLOCK_NUMS	24
#define SPRD_EFUSE_NORMAL_BLOCK_OFFSET	72

/* Timeout (ms) for the trylock of hardware spinlocks */
#define SPRD_EFUSE_HWLOCK_TIMEOUT	5000

/*
 * Since different Spreadtrum SoC chip can have different normal block numbers
 * and offset. And some SoC can support block double feature, which means
 * when reading or writing data to efuse memory, the controller can save double
 * data in case one data become incorrect after a long period.
 *
 * Thus we should save them in the device data structure.
 */
struct sprd_efuse_variant_data {
	u32 blk_nums;
	u32 blk_offset;
	bool blk_double;
};

struct sprd_efuse {
	struct device *dev;
	struct clk *clk;
	struct hwspinlock *hwlock;
	struct mutex mutex;
	void __iomem *base;
	const struct sprd_efuse_variant_data *data;
};

static const struct sprd_efuse_variant_data ums312_data = {
	.blk_nums = SPRD_EFUSE_NORMAL_BLOCK_NUMS,
	.blk_offset = SPRD_EFUSE_NORMAL_BLOCK_OFFSET,
	.blk_double = false,
};

/*
 * On Spreadtrum platform, we have multi-subsystems will access the unique
 * efuse controller, so we need one hardware spinlock to synchronize between
 * the multiple subsystems.
 */
static int sprd_efuse_lock(struct sprd_efuse *efuse)
{
	int ret;

	mutex_lock(&efuse->mutex);

	ret = hwspin_lock_timeout_raw(efuse->hwlock,
				      SPRD_EFUSE_HWLOCK_TIMEOUT);
	if (ret) {
		dev_err(efuse->dev, "timeout get the hwspinlock\n");
		mutex_unlock(&efuse->mutex);
		return ret;
	}

	return 0;
}

static void sprd_efuse_unlock(struct sprd_efuse *efuse)
{
	hwspin_unlock_raw(efuse->hwlock);
	mutex_unlock(&efuse->mutex);
}

static void sprd_efuse_set_prog_power(struct sprd_efuse *efuse, bool en)
{
	u32 val = readl(efuse->base + SPRD_EFUSE_PW_SWT);

	if (en)
		val &= ~SPRD_EFUSE_ENK2_ON;
	else
		val &= ~SPRD_EFUSE_ENK1_ON;

	writel(val, efuse->base + SPRD_EFUSE_PW_SWT);

	/* Open or close efuse power need wait 1000us to make power stable. */
	usleep_range(1000, 1200);

	if (en)
		val |= SPRD_EFUSE_ENK1_ON;
	else
		val |= SPRD_EFUSE_ENK2_ON;

	writel(val, efuse->base + SPRD_EFUSE_PW_SWT);

	/* Open or close efuse power need wait 1000us to make power stable. */
	usleep_range(1000, 1200);
}

static void sprd_efuse_set_read_power(struct sprd_efuse *efuse, bool en)
{
	u32 val = readl(efuse->base + SPRD_EFUSE_ENABLE);

	if (en)
		val |= SPRD_EFUSE_VDD_EN;
	else
		val &= ~SPRD_EFUSE_VDD_EN;

	writel(val, efuse->base + SPRD_EFUSE_ENABLE);

	/* Open or close efuse power need wait 1000us to make power stable. */
	usleep_range(1000, 1200);
}

static void sprd_efuse_set_prog_lock(struct sprd_efuse *efuse, bool en)
{
	u32 val = readl(efuse->base + SPRD_EFUSE_ENABLE);

	if (en)
		val |= SPRD_EFUSE_LOCK_WR_EN;
	else
		val &= ~SPRD_EFUSE_LOCK_WR_EN;

	writel(val, efuse->base + SPRD_EFUSE_ENABLE);
}

static void sprd_efuse_set_auto_check(struct sprd_efuse *efuse, bool en)
{
	u32 val = readl(efuse->base + SPRD_EFUSE_ENABLE);

	if (en)
		val |= SPRD_EFUSE_AUTO_CHECK_EN;
	else
		val &= ~SPRD_EFUSE_AUTO_CHECK_EN;

	writel(val, efuse->base + SPRD_EFUSE_ENABLE);
}

static void sprd_efuse_set_data_double(struct sprd_efuse *efuse, bool en)
{
	u32 val = readl(efuse->base + SPRD_EFUSE_ENABLE);

	if (en)
		val |= SPRD_EFUSE_DOUBLE_EN;
	else
		val &= ~SPRD_EFUSE_DOUBLE_EN;

	writel(val, efuse->base + SPRD_EFUSE_ENABLE);
}

static void sprd_efuse_set_prog_en(struct sprd_efuse *efuse, bool en)
{
	u32 val = readl(efuse->base + SPRD_EFUSE_PW_SWT);

	if (en)
		val |= SPRD_EFUSE_PROG_EN;
	else
		val &= ~SPRD_EFUSE_PROG_EN;

	writel(val, efuse->base + SPRD_EFUSE_PW_SWT);
}

static int sprd_efuse_raw_prog(struct sprd_efuse *efuse, u32 blk, bool doub,
			       bool lock, u32 *data)
{
	u32 status;
	int ret = 0;

	/*
	 * We need set the correct magic number before writing the efuse to
	 * allow programming, and block other programming until we clear the
	 * magic number.
	 */
	writel(SPRD_EFUSE_MAGIC_NUMBER,
	       efuse->base + SPRD_EFUSE_MAGIC_NUM);

	/*
	 * Power on the efuse, enable programme and enable double data
	 * if asked.
	 */
	sprd_efuse_set_prog_power(efuse, true);
	sprd_efuse_set_prog_en(efuse, true);
	sprd_efuse_set_data_double(efuse, doub);

	/*
	 * Enable the auto-check function to validate if the programming is
	 * successful.
	 */
	if (lock)
		sprd_efuse_set_auto_check(efuse, true);

	writel(*data, efuse->base + SPRD_EFUSE_MEM(blk));

	/* Disable auto-check and data double after programming */
	if (lock)
		sprd_efuse_set_auto_check(efuse, false);
	sprd_efuse_set_data_double(efuse, false);

	/*
	 * Check the efuse error status, if the programming is successful,
	 * we should lock this efuse block to avoid programming again.
	 */
	status = readl(efuse->base + SPRD_EFUSE_ERR_FLAG);
	if (status) {
		dev_err(efuse->dev,
			"write error status %d of block %d\n", ret, blk);

		writel(SPRD_EFUSE_ERR_CLR_MASK,
		       efuse->base + SPRD_EFUSE_ERR_CLR);
		ret = -EBUSY;
	} else if (lock) {
		sprd_efuse_set_prog_lock(efuse, lock);
		writel(0, efuse->base + SPRD_EFUSE_MEM(blk));
		sprd_efuse_set_prog_lock(efuse, false);
	}

	sprd_efuse_set_prog_power(efuse, false);
	writel(0, efuse->base + SPRD_EFUSE_MAGIC_NUM);

	return ret;
}

static int sprd_efuse_raw_read(struct sprd_efuse *efuse, int blk, u32 *val,
			       bool doub)
{
	u32 status;

	/*
	 * Need power on the efuse before reading data from efuse, and will
	 * power off the efuse after reading process.
	 */
	sprd_efuse_set_read_power(efuse, true);

	/* Enable double data if asked */
	sprd_efuse_set_data_double(efuse, doub);

	/* Start to read data from efuse block */
	*val = readl(efuse->base + SPRD_EFUSE_MEM(blk));

	/* Disable double data */
	sprd_efuse_set_data_double(efuse, false);

	/* Power off the efuse */
	sprd_efuse_set_read_power(efuse, false);

	/*
	 * Check the efuse error status and clear them if there are some
	 * errors occurred.
	 */
	status = readl(efuse->base + SPRD_EFUSE_ERR_FLAG);
	if (status) {
		dev_err(efuse->dev,
			"read error status %d of block %d\n", status, blk);

		writel(SPRD_EFUSE_ERR_CLR_MASK,
		       efuse->base + SPRD_EFUSE_ERR_CLR);
		return -EBUSY;
	}

	return 0;
}

static int sprd_efuse_read(void *context, u32 offset, void *val, size_t bytes)
{
	struct sprd_efuse *efuse = context;
	bool blk_double = efuse->data->blk_double;
	u32 index = offset / SPRD_EFUSE_BLOCK_WIDTH + efuse->data->blk_offset;
	u32 blk_offset = (offset % SPRD_EFUSE_BLOCK_WIDTH) * BITS_PER_BYTE;
	u32 data;
	int ret;

	ret = sprd_efuse_lock(efuse);
	if (ret)
		return ret;

	ret = clk_prepare_enable(efuse->clk);
	if (ret)
		goto unlock;

	ret = sprd_efuse_raw_read(efuse, index, &data, blk_double);
	if (!ret) {
		data >>= blk_offset;
		memcpy(val, &data, bytes);
	}

	clk_disable_unprepare(efuse->clk);

unlock:
	sprd_efuse_unlock(efuse);
	return ret;
}

static int sprd_efuse_write(void *context, u32 offset, void *val, size_t bytes)
{
	struct sprd_efuse *efuse = context;
	bool blk_double = efuse->data->blk_double;
	bool lock;
	int ret;

	ret = sprd_efuse_lock(efuse);
	if (ret)
		return ret;

	ret = clk_prepare_enable(efuse->clk);
	if (ret)
		goto unlock;

	/*
	 * If the writing bytes are equal with the block width, which means the
	 * whole block will be programmed. For this case, we should not allow
	 * this block to be programmed again by locking this block.
	 *
	 * If the block was programmed partially, we should allow this block to
	 * be programmed again.
	 */
	if (bytes < SPRD_EFUSE_BLOCK_WIDTH)
		lock = false;
	else
		lock = true;

	ret = sprd_efuse_raw_prog(efuse, offset, blk_double, lock, val);

	clk_disable_unprepare(efuse->clk);

unlock:
	sprd_efuse_unlock(efuse);
	return ret;
}

static int sprd_efuse_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct nvmem_device *nvmem;
	struct nvmem_config econfig = { };
	struct sprd_efuse *efuse;
	const struct sprd_efuse_variant_data *pdata;
	int ret;

	pdata = of_device_get_match_data(&pdev->dev);
	if (!pdata) {
		dev_err(&pdev->dev, "No matching driver data found\n");
		return -EINVAL;
	}

	efuse = devm_kzalloc(&pdev->dev, sizeof(*efuse), GFP_KERNEL);
	if (!efuse)
		return -ENOMEM;

	efuse->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(efuse->base))
		return PTR_ERR(efuse->base);

	ret = of_hwspin_lock_get_id(np, 0);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to get hwlock id\n");
		return ret;
	}

	efuse->hwlock = devm_hwspin_lock_request_specific(&pdev->dev, ret);
	if (!efuse->hwlock) {
		dev_err(&pdev->dev, "failed to request hwlock\n");
		return -ENXIO;
	}

	efuse->clk = devm_clk_get(&pdev->dev, "enable");
	if (IS_ERR(efuse->clk)) {
		dev_err(&pdev->dev, "failed to get enable clock\n");
		return PTR_ERR(efuse->clk);
	}

	mutex_init(&efuse->mutex);
	efuse->dev = &pdev->dev;
	efuse->data = pdata;

	econfig.stride = 1;
	econfig.word_size = 1;
	econfig.read_only = false;
	econfig.name = "sprd-efuse";
	econfig.size = efuse->data->blk_nums * SPRD_EFUSE_BLOCK_WIDTH;
	econfig.reg_read = sprd_efuse_read;
	econfig.reg_write = sprd_efuse_write;
	econfig.priv = efuse;
	econfig.dev = &pdev->dev;
	nvmem = devm_nvmem_register(&pdev->dev, &econfig);
	if (IS_ERR(nvmem)) {
		dev_err(&pdev->dev, "failed to register nvmem\n");
		return PTR_ERR(nvmem);
	}

	return 0;
}

static const struct of_device_id sprd_efuse_of_match[] = {
	{ .compatible = "sprd,ums312-efuse", .data = &ums312_data },
	{ }
};

static struct platform_driver sprd_efuse_driver = {
	.probe = sprd_efuse_probe,
	.driver = {
		.name = "sprd-efuse",
		.of_match_table = sprd_efuse_of_match,
	},
};

module_platform_driver(sprd_efuse_driver);

MODULE_AUTHOR("Freeman Liu <freeman.liu@spreadtrum.com>");
MODULE_DESCRIPTION("Spreadtrum AP efuse driver");
MODULE_LICENSE("GPL v2");