summaryrefslogtreecommitdiffstats
path: root/drivers/rpmsg/qcom_glink_rpm.c
blob: f64f45d1a735a6933fe109699aed4f6b11eb0f0c (plain) (blame)
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
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2016-2017, Linaro Ltd
 */

#include <linux/idr.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/list.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/rpmsg.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/mailbox_client.h>

#include "rpmsg_internal.h"
#include "qcom_glink_native.h"

#define RPM_TOC_SIZE		256
#define RPM_TOC_MAGIC		0x67727430 /* grt0 */
#define RPM_TOC_MAX_ENTRIES	((RPM_TOC_SIZE - sizeof(struct rpm_toc)) / \
				 sizeof(struct rpm_toc_entry))

#define RPM_TX_FIFO_ID		0x61703272 /* ap2r */
#define RPM_RX_FIFO_ID		0x72326170 /* r2ap */

#define to_rpm_pipe(p) container_of(p, struct glink_rpm_pipe, native)

struct rpm_toc_entry {
	__le32 id;
	__le32 offset;
	__le32 size;
} __packed;

struct rpm_toc {
	__le32 magic;
	__le32 count;

	struct rpm_toc_entry entries[];
} __packed;

struct glink_rpm_pipe {
	struct qcom_glink_pipe native;

	void __iomem *tail;
	void __iomem *head;

	void __iomem *fifo;
};

static size_t glink_rpm_rx_avail(struct qcom_glink_pipe *glink_pipe)
{
	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
	unsigned int head;
	unsigned int tail;

	head = readl(pipe->head);
	tail = readl(pipe->tail);

	if (head < tail)
		return pipe->native.length - tail + head;
	else
		return head - tail;
}

static void glink_rpm_rx_peak(struct qcom_glink_pipe *glink_pipe,
			      void *data, unsigned int offset, size_t count)
{
	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
	unsigned int tail;
	size_t len;

	tail = readl(pipe->tail);
	tail += offset;
	if (tail >= pipe->native.length)
		tail -= pipe->native.length;

	len = min_t(size_t, count, pipe->native.length - tail);
	if (len) {
		__ioread32_copy(data, pipe->fifo + tail,
				len / sizeof(u32));
	}

	if (len != count) {
		__ioread32_copy(data + len, pipe->fifo,
				(count - len) / sizeof(u32));
	}
}

static void glink_rpm_rx_advance(struct qcom_glink_pipe *glink_pipe,
				 size_t count)
{
	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
	unsigned int tail;

	tail = readl(pipe->tail);

	tail += count;
	if (tail >= pipe->native.length)
		tail -= pipe->native.length;

	writel(tail, pipe->tail);
}

static size_t glink_rpm_tx_avail(struct qcom_glink_pipe *glink_pipe)
{
	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
	unsigned int head;
	unsigned int tail;

	head = readl(pipe->head);
	tail = readl(pipe->tail);

	if (tail <= head)
		return pipe->native.length - head + tail;
	else
		return tail - head;
}

static unsigned int glink_rpm_tx_write_one(struct glink_rpm_pipe *pipe,
					   unsigned int head,
					   const void *data, size_t count)
{
	size_t len;

	len = min_t(size_t, count, pipe->native.length - head);
	if (len) {
		__iowrite32_copy(pipe->fifo + head, data,
				 len / sizeof(u32));
	}

	if (len != count) {
		__iowrite32_copy(pipe->fifo, data + len,
				 (count - len) / sizeof(u32));
	}

	head += count;
	if (head >= pipe->native.length)
		head -= pipe->native.length;

	return head;
}

static void glink_rpm_tx_write(struct qcom_glink_pipe *glink_pipe,
			       const void *hdr, size_t hlen,
			       const void *data, size_t dlen)
{
	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
	size_t tlen = hlen + dlen;
	size_t aligned_dlen;
	unsigned int head;
	char padding[8] = {0};
	size_t pad;

	/* Header length comes from glink native and is always 4 byte aligned */
	if (WARN(hlen % 4, "Glink Header length must be 4 bytes aligned\n"))
		return;

	/*
	 * Move the unaligned tail of the message to the padding chunk, to
	 * ensure word aligned accesses
	 */
	aligned_dlen = ALIGN_DOWN(dlen, 4);
	if (aligned_dlen != dlen)
		memcpy(padding, data + aligned_dlen, dlen - aligned_dlen);

	head = readl(pipe->head);
	head = glink_rpm_tx_write_one(pipe, head, hdr, hlen);
	head = glink_rpm_tx_write_one(pipe, head, data, aligned_dlen);

	pad = ALIGN(tlen, 8) - ALIGN_DOWN(tlen, 4);
	if (pad)
		head = glink_rpm_tx_write_one(pipe, head, padding, pad);
	writel(head, pipe->head);
}

static int glink_rpm_parse_toc(struct device *dev,
			       void __iomem *msg_ram,
			       size_t msg_ram_size,
			       struct glink_rpm_pipe *rx,
			       struct glink_rpm_pipe *tx)
{
	struct rpm_toc *toc;
	int num_entries;
	unsigned int id;
	size_t offset;
	size_t size;
	void *buf;
	int i;

	buf = kzalloc(RPM_TOC_SIZE, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	__ioread32_copy(buf, msg_ram + msg_ram_size - RPM_TOC_SIZE,
			RPM_TOC_SIZE / sizeof(u32));

	toc = buf;

	if (le32_to_cpu(toc->magic) != RPM_TOC_MAGIC) {
		dev_err(dev, "RPM TOC has invalid magic\n");
		goto err_inval;
	}

	num_entries = le32_to_cpu(toc->count);
	if (num_entries > RPM_TOC_MAX_ENTRIES) {
		dev_err(dev, "Invalid number of toc entries\n");
		goto err_inval;
	}

	for (i = 0; i < num_entries; i++) {
		id = le32_to_cpu(toc->entries[i].id);
		offset = le32_to_cpu(toc->entries[i].offset);
		size = le32_to_cpu(toc->entries[i].size);

		if (offset > msg_ram_size || offset + size > msg_ram_size) {
			dev_err(dev, "TOC entry with invalid size\n");
			continue;
		}

		switch (id) {
		case RPM_RX_FIFO_ID:
			rx->native.length = size;

			rx->tail = msg_ram + offset;
			rx->head = msg_ram + offset + sizeof(u32);
			rx->fifo = msg_ram + offset + 2 * sizeof(u32);
			break;
		case RPM_TX_FIFO_ID:
			tx->native.length = size;

			tx->tail = msg_ram + offset;
			tx->head = msg_ram + offset + sizeof(u32);
			tx->fifo = msg_ram + offset + 2 * sizeof(u32);
			break;
		}
	}

	if (!rx->fifo || !tx->fifo) {
		dev_err(dev, "Unable to find rx and tx descriptors\n");
		goto err_inval;
	}

	kfree(buf);
	return 0;

err_inval:
	kfree(buf);
	return -EINVAL;
}

static int glink_rpm_probe(struct platform_device *pdev)
{
	struct qcom_glink *glink;
	struct glink_rpm_pipe *rx_pipe;
	struct glink_rpm_pipe *tx_pipe;
	struct device_node *np;
	void __iomem *msg_ram;
	size_t msg_ram_size;
	struct device *dev = &pdev->dev;
	struct resource r;
	int ret;

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

	np = of_parse_phandle(dev->of_node, "qcom,rpm-msg-ram", 0);
	ret = of_address_to_resource(np, 0, &r);
	of_node_put(np);
	if (ret)
		return ret;

	msg_ram = devm_ioremap(dev, r.start, resource_size(&r));
	msg_ram_size = resource_size(&r);
	if (!msg_ram)
		return -ENOMEM;

	ret = glink_rpm_parse_toc(dev, msg_ram, msg_ram_size,
				  rx_pipe, tx_pipe);
	if (ret)
		return ret;

	/* Pipe specific accessors */
	rx_pipe->native.avail = glink_rpm_rx_avail;
	rx_pipe->native.peak = glink_rpm_rx_peak;
	rx_pipe->native.advance = glink_rpm_rx_advance;
	tx_pipe->native.avail = glink_rpm_tx_avail;
	tx_pipe->native.write = glink_rpm_tx_write;

	writel(0, tx_pipe->head);
	writel(0, rx_pipe->tail);

	glink = qcom_glink_native_probe(&pdev->dev,
					0,
					&rx_pipe->native,
					&tx_pipe->native,
					true);
	if (IS_ERR(glink))
		return PTR_ERR(glink);

	platform_set_drvdata(pdev, glink);

	return 0;
}

static int glink_rpm_remove(struct platform_device *pdev)
{
	struct qcom_glink *glink = platform_get_drvdata(pdev);

	qcom_glink_native_remove(glink);

	return 0;
}

static const struct of_device_id glink_rpm_of_match[] = {
	{ .compatible = "qcom,glink-rpm" },
	{}
};
MODULE_DEVICE_TABLE(of, glink_rpm_of_match);

static struct platform_driver glink_rpm_driver = {
	.probe = glink_rpm_probe,
	.remove = glink_rpm_remove,
	.driver = {
		.name = "qcom_glink_rpm",
		.of_match_table = glink_rpm_of_match,
	},
};

static int __init glink_rpm_init(void)
{
	return platform_driver_register(&glink_rpm_driver);
}
subsys_initcall(glink_rpm_init);

static void __exit glink_rpm_exit(void)
{
	platform_driver_unregister(&glink_rpm_driver);
}
module_exit(glink_rpm_exit);

MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@linaro.org>");
MODULE_DESCRIPTION("Qualcomm GLINK RPM driver");
MODULE_LICENSE("GPL v2");