1/*
2 * B53 register access through SPI
3 *
4 * Copyright (C) 2011-2013 Jonas Gorski <jogo@openwrt.org>
5 *
6 * Permission to use, copy, modify, and/or distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include <asm/unaligned.h>
20
21#include <linux/delay.h>
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/spi/spi.h>
25#include <linux/platform_data/b53.h>
26
27#include "b53_priv.h"
28
29#define B53_SPI_DATA		0xf0
30
31#define B53_SPI_STATUS		0xfe
32#define B53_SPI_CMD_SPIF	BIT(7)
33#define B53_SPI_CMD_RACK	BIT(5)
34
35#define B53_SPI_CMD_READ	0x00
36#define B53_SPI_CMD_WRITE	0x01
37#define B53_SPI_CMD_NORMAL	0x60
38#define B53_SPI_CMD_FAST	0x10
39
40#define B53_SPI_PAGE_SELECT	0xff
41
42static inline int b53_spi_read_reg(struct spi_device *spi, u8 reg, u8 *val,
43				   unsigned int len)
44{
45	u8 txbuf[2];
46
47	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_READ;
48	txbuf[1] = reg;
49
50	return spi_write_then_read(spi, txbuf, 2, val, len);
51}
52
53static inline int b53_spi_clear_status(struct spi_device *spi)
54{
55	unsigned int i;
56	u8 rxbuf;
57	int ret;
58
59	for (i = 0; i < 10; i++) {
60		ret = b53_spi_read_reg(spi, B53_SPI_STATUS, &rxbuf, 1);
61		if (ret)
62			return ret;
63
64		if (!(rxbuf & B53_SPI_CMD_SPIF))
65			break;
66
67		mdelay(1);
68	}
69
70	if (i == 10)
71		return -EIO;
72
73	return 0;
74}
75
76static inline int b53_spi_set_page(struct spi_device *spi, u8 page)
77{
78	u8 txbuf[3];
79
80	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
81	txbuf[1] = B53_SPI_PAGE_SELECT;
82	txbuf[2] = page;
83
84	return spi_write(spi, txbuf, sizeof(txbuf));
85}
86
87static inline int b53_prepare_reg_access(struct spi_device *spi, u8 page)
88{
89	int ret = b53_spi_clear_status(spi);
90
91	if (ret)
92		return ret;
93
94	return b53_spi_set_page(spi, page);
95}
96
97static int b53_spi_prepare_reg_read(struct spi_device *spi, u8 reg)
98{
99	u8 rxbuf;
100	int retry_count;
101	int ret;
102
103	ret = b53_spi_read_reg(spi, reg, &rxbuf, 1);
104	if (ret)
105		return ret;
106
107	for (retry_count = 0; retry_count < 10; retry_count++) {
108		ret = b53_spi_read_reg(spi, B53_SPI_STATUS, &rxbuf, 1);
109		if (ret)
110			return ret;
111
112		if (rxbuf & B53_SPI_CMD_RACK)
113			break;
114
115		mdelay(1);
116	}
117
118	if (retry_count == 10)
119		return -EIO;
120
121	return 0;
122}
123
124static int b53_spi_read(struct b53_device *dev, u8 page, u8 reg, u8 *data,
125			unsigned int len)
126{
127	struct spi_device *spi = dev->priv;
128	int ret;
129
130	ret = b53_prepare_reg_access(spi, page);
131	if (ret)
132		return ret;
133
134	ret = b53_spi_prepare_reg_read(spi, reg);
135	if (ret)
136		return ret;
137
138	return b53_spi_read_reg(spi, B53_SPI_DATA, data, len);
139}
140
141static int b53_spi_read8(struct b53_device *dev, u8 page, u8 reg, u8 *val)
142{
143	return b53_spi_read(dev, page, reg, val, 1);
144}
145
146static int b53_spi_read16(struct b53_device *dev, u8 page, u8 reg, u16 *val)
147{
148	__le16 value;
149	int ret;
150
151	ret = b53_spi_read(dev, page, reg, (u8 *)&value, 2);
152
153	if (!ret)
154		*val = le16_to_cpu(value);
155
156	return ret;
157}
158
159static int b53_spi_read32(struct b53_device *dev, u8 page, u8 reg, u32 *val)
160{
161	__le32 value;
162	int ret;
163
164	ret = b53_spi_read(dev, page, reg, (u8 *)&value, 4);
165
166	if (!ret)
167		*val = le32_to_cpu(value);
168
169	return ret;
170}
171
172static int b53_spi_read48(struct b53_device *dev, u8 page, u8 reg, u64 *val)
173{
174	__le64 value;
175	int ret;
176
177	*val = 0;
178	ret = b53_spi_read(dev, page, reg, (u8 *)&value, 6);
179	if (!ret)
180		*val = le64_to_cpu(value);
181
182	return ret;
183}
184
185static int b53_spi_read64(struct b53_device *dev, u8 page, u8 reg, u64 *val)
186{
187	__le64 value;
188	int ret;
189
190	ret = b53_spi_read(dev, page, reg, (u8 *)&value, 8);
191
192	if (!ret)
193		*val = le64_to_cpu(value);
194
195	return ret;
196}
197
198static int b53_spi_write8(struct b53_device *dev, u8 page, u8 reg, u8 value)
199{
200	struct spi_device *spi = dev->priv;
201	int ret;
202	u8 txbuf[3];
203
204	ret = b53_prepare_reg_access(spi, page);
205	if (ret)
206		return ret;
207
208	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
209	txbuf[1] = reg;
210	txbuf[2] = value;
211
212	return spi_write(spi, txbuf, sizeof(txbuf));
213}
214
215static int b53_spi_write16(struct b53_device *dev, u8 page, u8 reg, u16 value)
216{
217	struct spi_device *spi = dev->priv;
218	int ret;
219	u8 txbuf[4];
220
221	ret = b53_prepare_reg_access(spi, page);
222	if (ret)
223		return ret;
224
225	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
226	txbuf[1] = reg;
227	put_unaligned_le16(value, &txbuf[2]);
228
229	return spi_write(spi, txbuf, sizeof(txbuf));
230}
231
232static int b53_spi_write32(struct b53_device *dev, u8 page, u8 reg, u32 value)
233{
234	struct spi_device *spi = dev->priv;
235	int ret;
236	u8 txbuf[6];
237
238	ret = b53_prepare_reg_access(spi, page);
239	if (ret)
240		return ret;
241
242	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
243	txbuf[1] = reg;
244	put_unaligned_le32(value, &txbuf[2]);
245
246	return spi_write(spi, txbuf, sizeof(txbuf));
247}
248
249static int b53_spi_write48(struct b53_device *dev, u8 page, u8 reg, u64 value)
250{
251	struct spi_device *spi = dev->priv;
252	int ret;
253	u8 txbuf[10];
254
255	ret = b53_prepare_reg_access(spi, page);
256	if (ret)
257		return ret;
258
259	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
260	txbuf[1] = reg;
261	put_unaligned_le64(value, &txbuf[2]);
262
263	return spi_write(spi, txbuf, sizeof(txbuf) - 2);
264}
265
266static int b53_spi_write64(struct b53_device *dev, u8 page, u8 reg, u64 value)
267{
268	struct spi_device *spi = dev->priv;
269	int ret;
270	u8 txbuf[10];
271
272	ret = b53_prepare_reg_access(spi, page);
273	if (ret)
274		return ret;
275
276	txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
277	txbuf[1] = reg;
278	put_unaligned_le64(value, &txbuf[2]);
279
280	return spi_write(spi, txbuf, sizeof(txbuf));
281}
282
283static const struct b53_io_ops b53_spi_ops = {
284	.read8 = b53_spi_read8,
285	.read16 = b53_spi_read16,
286	.read32 = b53_spi_read32,
287	.read48 = b53_spi_read48,
288	.read64 = b53_spi_read64,
289	.write8 = b53_spi_write8,
290	.write16 = b53_spi_write16,
291	.write32 = b53_spi_write32,
292	.write48 = b53_spi_write48,
293	.write64 = b53_spi_write64,
294};
295
296static int b53_spi_probe(struct spi_device *spi)
297{
298	struct b53_device *dev;
299	int ret;
300
301	dev = b53_switch_alloc(&spi->dev, &b53_spi_ops, spi);
302	if (!dev)
303		return -ENOMEM;
304
305	if (spi->dev.platform_data)
306		dev->pdata = spi->dev.platform_data;
307
308	ret = b53_switch_register(dev);
309	if (ret)
310		return ret;
311
312	spi_set_drvdata(spi, dev);
313
314	return 0;
315}
316
317static void b53_spi_remove(struct spi_device *spi)
318{
319	struct b53_device *dev = spi_get_drvdata(spi);
320
321	if (dev)
322		b53_switch_remove(dev);
323}
324
325static void b53_spi_shutdown(struct spi_device *spi)
326{
327	struct b53_device *dev = spi_get_drvdata(spi);
328
329	if (dev)
330		b53_switch_shutdown(dev);
331
332	spi_set_drvdata(spi, NULL);
333}
334
335static const struct of_device_id b53_spi_of_match[] = {
336	{ .compatible = "brcm,bcm5325" },
337	{ .compatible = "brcm,bcm5365" },
338	{ .compatible = "brcm,bcm5395" },
339	{ .compatible = "brcm,bcm5397" },
340	{ .compatible = "brcm,bcm5398" },
341	{ .compatible = "brcm,bcm53115" },
342	{ .compatible = "brcm,bcm53125" },
343	{ .compatible = "brcm,bcm53128" },
344	{ /* sentinel */ }
345};
346MODULE_DEVICE_TABLE(of, b53_spi_of_match);
347
348static const struct spi_device_id b53_spi_ids[] = {
349	{ .name = "bcm5325" },
350	{ .name = "bcm5365" },
351	{ .name = "bcm5395" },
352	{ .name = "bcm5397" },
353	{ .name = "bcm5398" },
354	{ .name = "bcm53115" },
355	{ .name = "bcm53125" },
356	{ .name = "bcm53128" },
357	{ /* sentinel */ }
358};
359MODULE_DEVICE_TABLE(spi, b53_spi_ids);
360
361static struct spi_driver b53_spi_driver = {
362	.driver = {
363		.name	= "b53-switch",
364		.of_match_table = b53_spi_of_match,
365	},
366	.probe	= b53_spi_probe,
367	.remove	= b53_spi_remove,
368	.shutdown = b53_spi_shutdown,
369	.id_table = b53_spi_ids,
370};
371
372module_spi_driver(b53_spi_driver);
373
374MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
375MODULE_DESCRIPTION("B53 SPI access driver");
376MODULE_LICENSE("Dual BSD/GPL");
377