summaryrefslogtreecommitdiffstats
path: root/drivers/base/regmap/regmap-mmio.c
blob: 8812bfb9e3b89256f4a5d1468cf45484b18e4cd1 (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
/*
 * Register map access API - MMIO support
 *
 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/slab.h>

struct regmap_mmio_context {
	void __iomem *regs;
	unsigned reg_bytes;
	unsigned val_bytes;
	unsigned pad_bytes;
	struct clk *clk;
};

static inline void regmap_mmio_regsize_check(size_t reg_size)
{
	switch (reg_size) {
	case 1:
	case 2:
	case 4:
#ifdef CONFIG_64BIT
	case 8:
#endif
		break;
	default:
		BUG();
	}
}

static int regmap_mmio_regbits_check(size_t reg_bits)
{
	switch (reg_bits) {
	case 8:
	case 16:
	case 32:
#ifdef CONFIG_64BIT
	case 64:
#endif
		return 0;
	default:
		return -EINVAL;
	}
}

static int regmap_mmio_get_min_stride(size_t val_bits)
{
	int min_stride;

	switch (val_bits) {
	case 8:
		/* The core treats 0 as 1 */
		min_stride = 0;
		return 0;
	case 16:
		min_stride = 2;
		break;
	case 32:
		min_stride = 4;
		break;
#ifdef CONFIG_64BIT
	case 64:
		min_stride = 8;
		break;
#endif
	default:
		return -EINVAL;
	}

	return min_stride;
}

static inline void regmap_mmio_count_check(size_t count, u32 offset)
{
	BUG_ON(count <= offset);
}

static inline unsigned int
regmap_mmio_get_offset(const void *reg, size_t reg_size)
{
	switch (reg_size) {
	case 1:
		return *(u8 *)reg;
	case 2:
		return *(u16 *)reg;
	case 4:
		return *(u32 *)reg;
#ifdef CONFIG_64BIT
	case 8:
		return *(u64 *)reg;
#endif
	default:
		BUG();
	}
}

static int regmap_mmio_gather_write(void *context,
				    const void *reg, size_t reg_size,
				    const void *val, size_t val_size)
{
	struct regmap_mmio_context *ctx = context;
	unsigned int offset;
	int ret;

	regmap_mmio_regsize_check(reg_size);

	if (!IS_ERR(ctx->clk)) {
		ret = clk_enable(ctx->clk);
		if (ret < 0)
			return ret;
	}

	offset = regmap_mmio_get_offset(reg, reg_size);

	while (val_size) {
		switch (ctx->val_bytes) {
		case 1:
			__raw_writeb(*(u8 *)val, ctx->regs + offset);
			break;
		case 2:
			__raw_writew(*(u16 *)val, ctx->regs + offset);
			break;
		case 4:
			__raw_writel(*(u32 *)val, ctx->regs + offset);
			break;
#ifdef CONFIG_64BIT
		case 8:
			__raw_writeq(*(u64 *)val, ctx->regs + offset);
			break;
#endif
		default:
			/* Should be caught by regmap_mmio_check_config */
			BUG();
		}
		val_size -= ctx->val_bytes;
		val += ctx->val_bytes;
		offset += ctx->val_bytes;
	}

	if (!IS_ERR(ctx->clk))
		clk_disable(ctx->clk);

	return 0;
}

static int regmap_mmio_write(void *context, const void *data, size_t count)
{
	struct regmap_mmio_context *ctx = context;
	unsigned int offset = ctx->reg_bytes + ctx->pad_bytes;

	regmap_mmio_count_check(count, offset);

	return regmap_mmio_gather_write(context, data, ctx->reg_bytes,
					data + offset, count - offset);
}

static int regmap_mmio_read(void *context,
			    const void *reg, size_t reg_size,
			    void *val, size_t val_size)
{
	struct regmap_mmio_context *ctx = context;
	unsigned int offset;
	int ret;

	regmap_mmio_regsize_check(reg_size);

	if (!IS_ERR(ctx->clk)) {
		ret = clk_enable(ctx->clk);
		if (ret < 0)
			return ret;
	}

	offset = regmap_mmio_get_offset(reg, reg_size);

	while (val_size) {
		switch (ctx->val_bytes) {
		case 1:
			*(u8 *)val = __raw_readb(ctx->regs + offset);
			break;
		case 2:
			*(u16 *)val = __raw_readw(ctx->regs + offset);
			break;
		case 4:
			*(u32 *)val = __raw_readl(ctx->regs + offset);
			break;
#ifdef CONFIG_64BIT
		case 8:
			*(u64 *)val = __raw_readq(ctx->regs + offset);
			break;
#endif
		default:
			/* Should be caught by regmap_mmio_check_config */
			BUG();
		}
		val_size -= ctx->val_bytes;
		val += ctx->val_bytes;
		offset += ctx->val_bytes;
	}

	if (!IS_ERR(ctx->clk))
		clk_disable(ctx->clk);

	return 0;
}

static void regmap_mmio_free_context(void *context)
{
	struct regmap_mmio_context *ctx = context;

	if (!IS_ERR(ctx->clk)) {
		clk_unprepare(ctx->clk);
		clk_put(ctx->clk);
	}
	kfree(context);
}

static struct regmap_bus regmap_mmio = {
	.fast_io = true,
	.write = regmap_mmio_write,
	.gather_write = regmap_mmio_gather_write,
	.read = regmap_mmio_read,
	.free_context = regmap_mmio_free_context,
	.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
	.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
};

static struct regmap_mmio_context *regmap_mmio_gen_context(struct device *dev,
					const char *clk_id,
					void __iomem *regs,
					const struct regmap_config *config)
{
	struct regmap_mmio_context *ctx;
	int min_stride;
	int ret;

	ret = regmap_mmio_regbits_check(config->reg_bits);
	if (ret)
		return ERR_PTR(ret);

	if (config->pad_bits)
		return ERR_PTR(-EINVAL);

	min_stride = regmap_mmio_get_min_stride(config->val_bits);
	if (min_stride < 0)
		return ERR_PTR(min_stride);

	if (config->reg_stride < min_stride)
		return ERR_PTR(-EINVAL);

	switch (config->reg_format_endian) {
	case REGMAP_ENDIAN_DEFAULT:
	case REGMAP_ENDIAN_NATIVE:
		break;
	default:
		return ERR_PTR(-EINVAL);
	}

	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
	if (!ctx)
		return ERR_PTR(-ENOMEM);

	ctx->regs = regs;
	ctx->val_bytes = config->val_bits / 8;
	ctx->reg_bytes = config->reg_bits / 8;
	ctx->pad_bytes = config->pad_bits / 8;
	ctx->clk = ERR_PTR(-ENODEV);

	if (clk_id == NULL)
		return ctx;

	ctx->clk = clk_get(dev, clk_id);
	if (IS_ERR(ctx->clk)) {
		ret = PTR_ERR(ctx->clk);
		goto err_free;
	}

	ret = clk_prepare(ctx->clk);
	if (ret < 0) {
		clk_put(ctx->clk);
		goto err_free;
	}

	return ctx;

err_free:
	kfree(ctx);

	return ERR_PTR(ret);
}

struct regmap *__regmap_init_mmio_clk(struct device *dev, const char *clk_id,
				      void __iomem *regs,
				      const struct regmap_config *config,
				      struct lock_class_key *lock_key,
				      const char *lock_name)
{
	struct regmap_mmio_context *ctx;

	ctx = regmap_mmio_gen_context(dev, clk_id, regs, config);
	if (IS_ERR(ctx))
		return ERR_CAST(ctx);

	return __regmap_init(dev, &regmap_mmio, ctx, config,
			     lock_key, lock_name);
}
EXPORT_SYMBOL_GPL(__regmap_init_mmio_clk);

struct regmap *__devm_regmap_init_mmio_clk(struct device *dev,
					   const char *clk_id,
					   void __iomem *regs,
					   const struct regmap_config *config,
					   struct lock_class_key *lock_key,
					   const char *lock_name)
{
	struct regmap_mmio_context *ctx;

	ctx = regmap_mmio_gen_context(dev, clk_id, regs, config);
	if (IS_ERR(ctx))
		return ERR_CAST(ctx);

	return __devm_regmap_init(dev, &regmap_mmio, ctx, config,
				  lock_key, lock_name);
}
EXPORT_SYMBOL_GPL(__devm_regmap_init_mmio_clk);

MODULE_LICENSE("GPL v2");