xref: /openbmc/u-boot/drivers/spi/spi-uclass.c (revision 28522678)
1 /*
2  * Copyright (c) 2014 Google, Inc
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #include <common.h>
8 #include <dm.h>
9 #include <errno.h>
10 #include <fdtdec.h>
11 #include <malloc.h>
12 #include <spi.h>
13 #include <dm/device-internal.h>
14 #include <dm/uclass-internal.h>
15 #include <dm/lists.h>
16 #include <dm/util.h>
17 
18 DECLARE_GLOBAL_DATA_PTR;
19 
20 static int spi_set_speed_mode(struct udevice *bus, int speed, int mode)
21 {
22 	struct dm_spi_ops *ops;
23 	int ret;
24 
25 	ops = spi_get_ops(bus);
26 	if (ops->set_speed)
27 		ret = ops->set_speed(bus, speed);
28 	else
29 		ret = -EINVAL;
30 	if (ret) {
31 		printf("Cannot set speed (err=%d)\n", ret);
32 		return ret;
33 	}
34 
35 	if (ops->set_mode)
36 		ret = ops->set_mode(bus, mode);
37 	else
38 		ret = -EINVAL;
39 	if (ret) {
40 		printf("Cannot set mode (err=%d)\n", ret);
41 		return ret;
42 	}
43 
44 	return 0;
45 }
46 
47 int dm_spi_claim_bus(struct udevice *dev)
48 {
49 	struct udevice *bus = dev->parent;
50 	struct dm_spi_ops *ops = spi_get_ops(bus);
51 	struct dm_spi_bus *spi = dev_get_uclass_priv(bus);
52 	struct spi_slave *slave = dev_get_parent_priv(dev);
53 	int speed;
54 	int ret;
55 
56 	speed = slave->max_hz;
57 	if (spi->max_hz) {
58 		if (speed)
59 			speed = min(speed, (int)spi->max_hz);
60 		else
61 			speed = spi->max_hz;
62 	}
63 	if (!speed)
64 		speed = 100000;
65 	if (speed != slave->speed) {
66 		ret = spi_set_speed_mode(bus, speed, slave->mode);
67 		if (ret)
68 			return ret;
69 		slave->speed = speed;
70 	}
71 
72 	return ops->claim_bus ? ops->claim_bus(dev) : 0;
73 }
74 
75 void dm_spi_release_bus(struct udevice *dev)
76 {
77 	struct udevice *bus = dev->parent;
78 	struct dm_spi_ops *ops = spi_get_ops(bus);
79 
80 	if (ops->release_bus)
81 		ops->release_bus(dev);
82 }
83 
84 int dm_spi_xfer(struct udevice *dev, unsigned int bitlen,
85 		const void *dout, void *din, unsigned long flags)
86 {
87 	struct udevice *bus = dev->parent;
88 
89 	if (bus->uclass->uc_drv->id != UCLASS_SPI)
90 		return -EOPNOTSUPP;
91 
92 	return spi_get_ops(bus)->xfer(dev, bitlen, dout, din, flags);
93 }
94 
95 int spi_claim_bus(struct spi_slave *slave)
96 {
97 	return dm_spi_claim_bus(slave->dev);
98 }
99 
100 void spi_release_bus(struct spi_slave *slave)
101 {
102 	dm_spi_release_bus(slave->dev);
103 }
104 
105 int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
106 	     const void *dout, void *din, unsigned long flags)
107 {
108 	return dm_spi_xfer(slave->dev, bitlen, dout, din, flags);
109 }
110 
111 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
112 static int spi_child_post_bind(struct udevice *dev)
113 {
114 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
115 
116 	if (dev_of_offset(dev) == -1)
117 		return 0;
118 
119 	return spi_slave_ofdata_to_platdata(gd->fdt_blob, dev_of_offset(dev),
120 					    plat);
121 }
122 #endif
123 
124 static int spi_post_probe(struct udevice *bus)
125 {
126 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
127 	struct dm_spi_bus *spi = dev_get_uclass_priv(bus);
128 
129 	spi->max_hz = fdtdec_get_int(gd->fdt_blob, dev_of_offset(bus),
130 				     "spi-max-frequency", 0);
131 #endif
132 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
133 	struct dm_spi_ops *ops = spi_get_ops(bus);
134 
135 
136 	if (ops->claim_bus)
137 		ops->claim_bus += gd->reloc_off;
138 	if (ops->release_bus)
139 		ops->release_bus += gd->reloc_off;
140 	if (ops->set_wordlen)
141 		ops->set_wordlen += gd->reloc_off;
142 	if (ops->xfer)
143 		ops->xfer += gd->reloc_off;
144 	if (ops->set_speed)
145 		ops->set_speed += gd->reloc_off;
146 	if (ops->set_mode)
147 		ops->set_mode += gd->reloc_off;
148 	if (ops->cs_info)
149 		ops->cs_info += gd->reloc_off;
150 #endif
151 
152 	return 0;
153 }
154 
155 static int spi_child_pre_probe(struct udevice *dev)
156 {
157 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
158 	struct spi_slave *slave = dev_get_parent_priv(dev);
159 
160 	/*
161 	 * This is needed because we pass struct spi_slave around the place
162 	 * instead slave->dev (a struct udevice). So we have to have some
163 	 * way to access the slave udevice given struct spi_slave. Once we
164 	 * change the SPI API to use udevice instead of spi_slave, we can
165 	 * drop this.
166 	 */
167 	slave->dev = dev;
168 
169 	slave->max_hz = plat->max_hz;
170 	slave->mode = plat->mode;
171 	slave->wordlen = SPI_DEFAULT_WORDLEN;
172 
173 	return 0;
174 }
175 
176 int spi_chip_select(struct udevice *dev)
177 {
178 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
179 
180 	return plat ? plat->cs : -ENOENT;
181 }
182 
183 int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp)
184 {
185 	struct udevice *dev;
186 
187 	for (device_find_first_child(bus, &dev); dev;
188 	     device_find_next_child(&dev)) {
189 		struct dm_spi_slave_platdata *plat;
190 
191 		plat = dev_get_parent_platdata(dev);
192 		debug("%s: plat=%p, cs=%d\n", __func__, plat, plat->cs);
193 		if (plat->cs == cs) {
194 			*devp = dev;
195 			return 0;
196 		}
197 	}
198 
199 	return -ENODEV;
200 }
201 
202 int spi_cs_is_valid(unsigned int busnum, unsigned int cs)
203 {
204 	struct spi_cs_info info;
205 	struct udevice *bus;
206 	int ret;
207 
208 	ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
209 	if (ret) {
210 		debug("%s: No bus %d\n", __func__, busnum);
211 		return ret;
212 	}
213 
214 	return spi_cs_info(bus, cs, &info);
215 }
216 
217 int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info)
218 {
219 	struct spi_cs_info local_info;
220 	struct dm_spi_ops *ops;
221 	int ret;
222 
223 	if (!info)
224 		info = &local_info;
225 
226 	/* If there is a device attached, return it */
227 	info->dev = NULL;
228 	ret = spi_find_chip_select(bus, cs, &info->dev);
229 	if (!ret)
230 		return 0;
231 
232 	/*
233 	 * Otherwise ask the driver. For the moment we don't have CS info.
234 	 * When we do we could provide the driver with a helper function
235 	 * to figure out what chip selects are valid, or just handle the
236 	 * request.
237 	 */
238 	ops = spi_get_ops(bus);
239 	if (ops->cs_info)
240 		return ops->cs_info(bus, cs, info);
241 
242 	/*
243 	 * We could assume there is at least one valid chip select, but best
244 	 * to be sure and return an error in this case. The driver didn't
245 	 * care enough to tell us.
246 	 */
247 	return -ENODEV;
248 }
249 
250 int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
251 			struct udevice **devp)
252 {
253 	struct udevice *bus, *dev;
254 	int ret;
255 
256 	ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
257 	if (ret) {
258 		debug("%s: No bus %d\n", __func__, busnum);
259 		return ret;
260 	}
261 	ret = spi_find_chip_select(bus, cs, &dev);
262 	if (ret) {
263 		debug("%s: No cs %d\n", __func__, cs);
264 		return ret;
265 	}
266 	*busp = bus;
267 	*devp = dev;
268 
269 	return ret;
270 }
271 
272 int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
273 		       const char *drv_name, const char *dev_name,
274 		       struct udevice **busp, struct spi_slave **devp)
275 {
276 	struct udevice *bus, *dev;
277 	struct dm_spi_slave_platdata *plat;
278 	bool created = false;
279 	int ret;
280 
281 #if CONFIG_IS_ENABLED(OF_PLATDATA)
282 	ret = uclass_first_device_err(UCLASS_SPI, &bus);
283 #else
284 	ret = uclass_get_device_by_seq(UCLASS_SPI, busnum, &bus);
285 #endif
286 	if (ret) {
287 		printf("Invalid bus %d (err=%d)\n", busnum, ret);
288 		return ret;
289 	}
290 	ret = spi_find_chip_select(bus, cs, &dev);
291 
292 	/*
293 	 * If there is no such device, create one automatically. This means
294 	 * that we don't need a device tree node or platform data for the
295 	 * SPI flash chip - we will bind to the correct driver.
296 	 */
297 	if (ret == -ENODEV && drv_name) {
298 		debug("%s: Binding new device '%s', busnum=%d, cs=%d, driver=%s\n",
299 		      __func__, dev_name, busnum, cs, drv_name);
300 		ret = device_bind_driver(bus, drv_name, dev_name, &dev);
301 		if (ret) {
302 			debug("%s: Unable to bind driver (ret=%d)\n", __func__,
303 			      ret);
304 			return ret;
305 		}
306 		plat = dev_get_parent_platdata(dev);
307 		plat->cs = cs;
308 		plat->max_hz = speed;
309 		plat->mode = mode;
310 		created = true;
311 	} else if (ret) {
312 		printf("Invalid chip select %d:%d (err=%d)\n", busnum, cs,
313 		       ret);
314 		return ret;
315 	}
316 
317 	if (!device_active(dev)) {
318 		struct spi_slave *slave;
319 
320 		ret = device_probe(dev);
321 		if (ret)
322 			goto err;
323 		slave = dev_get_parent_priv(dev);
324 		slave->dev = dev;
325 	}
326 
327 	plat = dev_get_parent_platdata(dev);
328 	if (!speed) {
329 		speed = plat->max_hz;
330 		mode = plat->mode;
331 	}
332 	ret = spi_set_speed_mode(bus, speed, mode);
333 	if (ret)
334 		goto err;
335 
336 	*busp = bus;
337 	*devp = dev_get_parent_priv(dev);
338 	debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp);
339 
340 	return 0;
341 
342 err:
343 	debug("%s: Error path, created=%d, device '%s'\n", __func__,
344 	      created, dev->name);
345 	if (created) {
346 		device_remove(dev);
347 		device_unbind(dev);
348 	}
349 
350 	return ret;
351 }
352 
353 /* Compatibility function - to be removed */
354 struct spi_slave *spi_setup_slave_fdt(const void *blob, int node,
355 				      int bus_node)
356 {
357 	struct udevice *bus, *dev;
358 	int ret;
359 
360 	ret = uclass_get_device_by_of_offset(UCLASS_SPI, bus_node, &bus);
361 	if (ret)
362 		return NULL;
363 	ret = device_get_child_by_of_offset(bus, node, &dev);
364 	if (ret)
365 		return NULL;
366 	return dev_get_parent_priv(dev);
367 }
368 
369 /* Compatibility function - to be removed */
370 struct spi_slave *spi_setup_slave(unsigned int busnum, unsigned int cs,
371 				  unsigned int speed, unsigned int mode)
372 {
373 	struct spi_slave *slave;
374 	struct udevice *dev;
375 	int ret;
376 
377 	ret = spi_get_bus_and_cs(busnum, cs, speed, mode, NULL, 0, &dev,
378 				  &slave);
379 	if (ret)
380 		return NULL;
381 
382 	return slave;
383 }
384 
385 void spi_free_slave(struct spi_slave *slave)
386 {
387 	device_remove(slave->dev);
388 	slave->dev = NULL;
389 }
390 
391 int spi_slave_ofdata_to_platdata(const void *blob, int node,
392 				 struct dm_spi_slave_platdata *plat)
393 {
394 	int mode = 0;
395 	int value;
396 
397 	plat->cs = fdtdec_get_int(blob, node, "reg", -1);
398 	plat->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency", 0);
399 	if (fdtdec_get_bool(blob, node, "spi-cpol"))
400 		mode |= SPI_CPOL;
401 	if (fdtdec_get_bool(blob, node, "spi-cpha"))
402 		mode |= SPI_CPHA;
403 	if (fdtdec_get_bool(blob, node, "spi-cs-high"))
404 		mode |= SPI_CS_HIGH;
405 	if (fdtdec_get_bool(blob, node, "spi-3wire"))
406 		mode |= SPI_3WIRE;
407 	if (fdtdec_get_bool(blob, node, "spi-half-duplex"))
408 		mode |= SPI_PREAMBLE;
409 
410 	/* Device DUAL/QUAD mode */
411 	value = fdtdec_get_uint(blob, node, "spi-tx-bus-width", 1);
412 	switch (value) {
413 	case 1:
414 		break;
415 	case 2:
416 		mode |= SPI_TX_DUAL;
417 		break;
418 	case 4:
419 		mode |= SPI_TX_QUAD;
420 		break;
421 	default:
422 		warn_non_spl("spi-tx-bus-width %d not supported\n", value);
423 		break;
424 	}
425 
426 	value = fdtdec_get_uint(blob, node, "spi-rx-bus-width", 1);
427 	switch (value) {
428 	case 1:
429 		break;
430 	case 2:
431 		mode |= SPI_RX_DUAL;
432 		break;
433 	case 4:
434 		mode |= SPI_RX_QUAD;
435 		break;
436 	default:
437 		warn_non_spl("spi-rx-bus-width %d not supported\n", value);
438 		break;
439 	}
440 
441 	plat->mode = mode;
442 
443 	return 0;
444 }
445 
446 UCLASS_DRIVER(spi) = {
447 	.id		= UCLASS_SPI,
448 	.name		= "spi",
449 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
450 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
451 	.post_bind	= dm_scan_fdt_dev,
452 #endif
453 	.post_probe	= spi_post_probe,
454 	.child_pre_probe = spi_child_pre_probe,
455 	.per_device_auto_alloc_size = sizeof(struct dm_spi_bus),
456 	.per_child_auto_alloc_size = sizeof(struct spi_slave),
457 	.per_child_platdata_auto_alloc_size =
458 			sizeof(struct dm_spi_slave_platdata),
459 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
460 	.child_post_bind = spi_child_post_bind,
461 #endif
462 };
463 
464 UCLASS_DRIVER(spi_generic) = {
465 	.id		= UCLASS_SPI_GENERIC,
466 	.name		= "spi_generic",
467 };
468 
469 U_BOOT_DRIVER(spi_generic_drv) = {
470 	.name		= "spi_generic_drv",
471 	.id		= UCLASS_SPI_GENERIC,
472 };
473