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c7c8c78f LW |
1 | /* |
2 | * arch/arm/mach-u300/dummyspichip.c | |
3 | * | |
4 | * Copyright (C) 2007-2009 ST-Ericsson AB | |
5 | * License terms: GNU General Public License (GPL) version 2 | |
6 | * This is a dummy loopback SPI "chip" used for testing SPI. | |
7 | * Author: Linus Walleij <linus.walleij@stericsson.com> | |
8 | */ | |
9 | #include <linux/init.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/kernel.h> | |
12 | #include <linux/device.h> | |
13 | #include <linux/err.h> | |
14 | #include <linux/sysfs.h> | |
15 | #include <linux/mutex.h> | |
16 | #include <linux/spi/spi.h> | |
17 | #include <linux/dma-mapping.h> | |
5a0e3ad6 | 18 | #include <linux/slab.h> |
c7c8c78f LW |
19 | /* |
20 | * WARNING! Do not include this pl022-specific controller header | |
21 | * for any generic driver. It is only done in this dummy chip | |
22 | * because we alter the chip configuration in order to test some | |
23 | * different settings on the loopback device. Normal chip configs | |
24 | * shall be STATIC and not altered by the driver! | |
25 | */ | |
26 | #include <linux/amba/pl022.h> | |
27 | ||
28 | struct dummy { | |
29 | struct device *dev; | |
30 | struct mutex lock; | |
31 | }; | |
32 | ||
33 | #define DMA_TEST_SIZE 2048 | |
34 | ||
35 | /* When we cat /sys/bus/spi/devices/spi0.0/looptest this will be triggered */ | |
36 | static ssize_t dummy_looptest(struct device *dev, | |
37 | struct device_attribute *attr, char *buf) | |
38 | { | |
39 | struct spi_device *spi = to_spi_device(dev); | |
40 | struct dummy *p_dummy = dev_get_drvdata(&spi->dev); | |
41 | ||
42 | /* | |
43 | * WARNING! Do not dereference the chip-specific data in any normal | |
44 | * driver for a chip. It is usually STATIC and shall not be read | |
45 | * or written to. Your chip driver should NOT depend on fields in this | |
46 | * struct, this is just used here to alter the behaviour of the chip | |
47 | * in order to perform tests. | |
48 | */ | |
c7c8c78f LW |
49 | int status; |
50 | u8 txbuf[14] = {0xDE, 0xAD, 0xBE, 0xEF, 0x2B, 0xAD, | |
51 | 0xCA, 0xFE, 0xBA, 0xBE, 0xB1, 0x05, | |
52 | 0xF0, 0x0D}; | |
53 | u8 rxbuf[14]; | |
54 | u8 *bigtxbuf_virtual; | |
55 | u8 *bigrxbuf_virtual; | |
56 | ||
57 | if (mutex_lock_interruptible(&p_dummy->lock)) | |
58 | return -ERESTARTSYS; | |
59 | ||
60 | bigtxbuf_virtual = kmalloc(DMA_TEST_SIZE, GFP_KERNEL); | |
61 | if (bigtxbuf_virtual == NULL) { | |
62 | status = -ENOMEM; | |
63 | goto out; | |
64 | } | |
65 | bigrxbuf_virtual = kmalloc(DMA_TEST_SIZE, GFP_KERNEL); | |
66 | ||
67 | /* Fill TXBUF with some happy pattern */ | |
68 | memset(bigtxbuf_virtual, 0xAA, DMA_TEST_SIZE); | |
69 | ||
70 | /* | |
71 | * Force chip to 8 bit mode | |
72 | * WARNING: NEVER DO THIS IN REAL DRIVER CODE, THIS SHOULD BE STATIC! | |
73 | */ | |
bde435a9 | 74 | spi->bits_per_word = 8; |
c7c8c78f LW |
75 | /* You should NOT DO THIS EITHER */ |
76 | spi->master->setup(spi); | |
77 | ||
78 | /* Now run the tests for 8bit mode */ | |
79 | pr_info("Simple test 1: write 0xAA byte, read back garbage byte " | |
80 | "in 8bit mode\n"); | |
81 | status = spi_w8r8(spi, 0xAA); | |
82 | if (status < 0) | |
83 | pr_warning("Siple test 1: FAILURE: spi_write_then_read " | |
84 | "failed with status %d\n", status); | |
85 | else | |
86 | pr_info("Simple test 1: SUCCESS!\n"); | |
87 | ||
88 | pr_info("Simple test 2: write 8 bytes, read back 8 bytes garbage " | |
89 | "in 8bit mode (full FIFO)\n"); | |
90 | status = spi_write_then_read(spi, &txbuf[0], 8, &rxbuf[0], 8); | |
91 | if (status < 0) | |
92 | pr_warning("Simple test 2: FAILURE: spi_write_then_read() " | |
93 | "failed with status %d\n", status); | |
94 | else | |
95 | pr_info("Simple test 2: SUCCESS!\n"); | |
96 | ||
97 | pr_info("Simple test 3: write 14 bytes, read back 14 bytes garbage " | |
98 | "in 8bit mode (see if we overflow FIFO)\n"); | |
99 | status = spi_write_then_read(spi, &txbuf[0], 14, &rxbuf[0], 14); | |
100 | if (status < 0) | |
101 | pr_warning("Simple test 3: FAILURE: failed with status %d " | |
102 | "(probably FIFO overrun)\n", status); | |
103 | else | |
104 | pr_info("Simple test 3: SUCCESS!\n"); | |
105 | ||
106 | pr_info("Simple test 4: write 8 bytes with spi_write(), read 8 " | |
107 | "bytes garbage with spi_read() in 8bit mode\n"); | |
108 | status = spi_write(spi, &txbuf[0], 8); | |
109 | if (status < 0) | |
110 | pr_warning("Simple test 4 step 1: FAILURE: spi_write() " | |
111 | "failed with status %d\n", status); | |
112 | else | |
113 | pr_info("Simple test 4 step 1: SUCCESS!\n"); | |
114 | status = spi_read(spi, &rxbuf[0], 8); | |
115 | if (status < 0) | |
116 | pr_warning("Simple test 4 step 2: FAILURE: spi_read() " | |
117 | "failed with status %d\n", status); | |
118 | else | |
119 | pr_info("Simple test 4 step 2: SUCCESS!\n"); | |
120 | ||
121 | pr_info("Simple test 5: write 14 bytes with spi_write(), read " | |
122 | "14 bytes garbage with spi_read() in 8bit mode\n"); | |
123 | status = spi_write(spi, &txbuf[0], 14); | |
124 | if (status < 0) | |
125 | pr_warning("Simple test 5 step 1: FAILURE: spi_write() " | |
126 | "failed with status %d (probably FIFO overrun)\n", | |
127 | status); | |
128 | else | |
129 | pr_info("Simple test 5 step 1: SUCCESS!\n"); | |
130 | status = spi_read(spi, &rxbuf[0], 14); | |
131 | if (status < 0) | |
132 | pr_warning("Simple test 5 step 2: FAILURE: spi_read() " | |
133 | "failed with status %d (probably FIFO overrun)\n", | |
134 | status); | |
135 | else | |
136 | pr_info("Simple test 5: SUCCESS!\n"); | |
137 | ||
138 | pr_info("Simple test 6: write %d bytes with spi_write(), " | |
139 | "read %d bytes garbage with spi_read() in 8bit mode\n", | |
140 | DMA_TEST_SIZE, DMA_TEST_SIZE); | |
141 | status = spi_write(spi, &bigtxbuf_virtual[0], DMA_TEST_SIZE); | |
142 | if (status < 0) | |
143 | pr_warning("Simple test 6 step 1: FAILURE: spi_write() " | |
144 | "failed with status %d (probably FIFO overrun)\n", | |
145 | status); | |
146 | else | |
147 | pr_info("Simple test 6 step 1: SUCCESS!\n"); | |
148 | status = spi_read(spi, &bigrxbuf_virtual[0], DMA_TEST_SIZE); | |
149 | if (status < 0) | |
150 | pr_warning("Simple test 6 step 2: FAILURE: spi_read() " | |
151 | "failed with status %d (probably FIFO overrun)\n", | |
152 | status); | |
153 | else | |
154 | pr_info("Simple test 6: SUCCESS!\n"); | |
155 | ||
156 | ||
157 | /* | |
158 | * Force chip to 16 bit mode | |
159 | * WARNING: NEVER DO THIS IN REAL DRIVER CODE, THIS SHOULD BE STATIC! | |
160 | */ | |
bde435a9 | 161 | spi->bits_per_word = 16; |
c7c8c78f LW |
162 | /* You should NOT DO THIS EITHER */ |
163 | spi->master->setup(spi); | |
164 | ||
165 | pr_info("Simple test 7: write 0xAA byte, read back garbage byte " | |
166 | "in 16bit bus mode\n"); | |
167 | status = spi_w8r8(spi, 0xAA); | |
168 | if (status == -EIO) | |
169 | pr_info("Simple test 7: SUCCESS! (expected failure with " | |
170 | "status EIO)\n"); | |
171 | else if (status < 0) | |
172 | pr_warning("Siple test 7: FAILURE: spi_write_then_read " | |
173 | "failed with status %d\n", status); | |
174 | else | |
175 | pr_warning("Siple test 7: FAILURE: spi_write_then_read " | |
176 | "succeeded but it was expected to fail!\n"); | |
177 | ||
178 | pr_info("Simple test 8: write 8 bytes, read back 8 bytes garbage " | |
179 | "in 16bit mode (full FIFO)\n"); | |
180 | status = spi_write_then_read(spi, &txbuf[0], 8, &rxbuf[0], 8); | |
181 | if (status < 0) | |
182 | pr_warning("Simple test 8: FAILURE: spi_write_then_read() " | |
183 | "failed with status %d\n", status); | |
184 | else | |
185 | pr_info("Simple test 8: SUCCESS!\n"); | |
186 | ||
187 | pr_info("Simple test 9: write 14 bytes, read back 14 bytes garbage " | |
188 | "in 16bit mode (see if we overflow FIFO)\n"); | |
189 | status = spi_write_then_read(spi, &txbuf[0], 14, &rxbuf[0], 14); | |
190 | if (status < 0) | |
191 | pr_warning("Simple test 9: FAILURE: failed with status %d " | |
192 | "(probably FIFO overrun)\n", status); | |
193 | else | |
194 | pr_info("Simple test 9: SUCCESS!\n"); | |
195 | ||
196 | pr_info("Simple test 10: write %d bytes with spi_write(), " | |
197 | "read %d bytes garbage with spi_read() in 16bit mode\n", | |
198 | DMA_TEST_SIZE, DMA_TEST_SIZE); | |
199 | status = spi_write(spi, &bigtxbuf_virtual[0], DMA_TEST_SIZE); | |
200 | if (status < 0) | |
201 | pr_warning("Simple test 10 step 1: FAILURE: spi_write() " | |
202 | "failed with status %d (probably FIFO overrun)\n", | |
203 | status); | |
204 | else | |
205 | pr_info("Simple test 10 step 1: SUCCESS!\n"); | |
206 | ||
207 | status = spi_read(spi, &bigrxbuf_virtual[0], DMA_TEST_SIZE); | |
208 | if (status < 0) | |
209 | pr_warning("Simple test 10 step 2: FAILURE: spi_read() " | |
210 | "failed with status %d (probably FIFO overrun)\n", | |
211 | status); | |
212 | else | |
213 | pr_info("Simple test 10: SUCCESS!\n"); | |
214 | ||
215 | status = sprintf(buf, "loop test complete\n"); | |
216 | kfree(bigrxbuf_virtual); | |
217 | kfree(bigtxbuf_virtual); | |
218 | out: | |
219 | mutex_unlock(&p_dummy->lock); | |
220 | return status; | |
221 | } | |
222 | ||
223 | static DEVICE_ATTR(looptest, S_IRUGO, dummy_looptest, NULL); | |
224 | ||
351a102d | 225 | static int pl022_dummy_probe(struct spi_device *spi) |
c7c8c78f LW |
226 | { |
227 | struct dummy *p_dummy; | |
228 | int status; | |
229 | ||
230 | dev_info(&spi->dev, "probing dummy SPI device\n"); | |
231 | ||
232 | p_dummy = kzalloc(sizeof *p_dummy, GFP_KERNEL); | |
233 | if (!p_dummy) | |
234 | return -ENOMEM; | |
235 | ||
236 | dev_set_drvdata(&spi->dev, p_dummy); | |
237 | mutex_init(&p_dummy->lock); | |
238 | ||
239 | /* sysfs hook */ | |
240 | status = device_create_file(&spi->dev, &dev_attr_looptest); | |
241 | if (status) { | |
242 | dev_dbg(&spi->dev, "device_create_file looptest failure.\n"); | |
243 | goto out_dev_create_looptest_failed; | |
244 | } | |
245 | ||
246 | return 0; | |
247 | ||
248 | out_dev_create_looptest_failed: | |
249 | dev_set_drvdata(&spi->dev, NULL); | |
250 | kfree(p_dummy); | |
251 | return status; | |
252 | } | |
253 | ||
351a102d | 254 | static int pl022_dummy_remove(struct spi_device *spi) |
c7c8c78f LW |
255 | { |
256 | struct dummy *p_dummy = dev_get_drvdata(&spi->dev); | |
257 | ||
258 | dev_info(&spi->dev, "removing dummy SPI device\n"); | |
259 | device_remove_file(&spi->dev, &dev_attr_looptest); | |
260 | dev_set_drvdata(&spi->dev, NULL); | |
261 | kfree(p_dummy); | |
262 | ||
263 | return 0; | |
264 | } | |
265 | ||
20d4af68 LW |
266 | static const struct of_device_id pl022_dummy_dt_match[] = { |
267 | { .compatible = "arm,pl022-dummy" }, | |
268 | {}, | |
269 | }; | |
270 | ||
c7c8c78f LW |
271 | static struct spi_driver pl022_dummy_driver = { |
272 | .driver = { | |
273 | .name = "spi-dummy", | |
274 | .owner = THIS_MODULE, | |
20d4af68 | 275 | .of_match_table = pl022_dummy_dt_match, |
c7c8c78f LW |
276 | }, |
277 | .probe = pl022_dummy_probe, | |
351a102d | 278 | .remove = pl022_dummy_remove, |
c7c8c78f LW |
279 | }; |
280 | ||
be2885a5 | 281 | module_spi_driver(pl022_dummy_driver); |
c7c8c78f LW |
282 | MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>"); |
283 | MODULE_DESCRIPTION("PL022 SSP/SPI DUMMY Linux driver"); | |
284 | MODULE_LICENSE("GPL"); |