xref: /openbmc/u-boot/drivers/spi/spi-uclass.c (revision 2e3f1ff63f50f36e74d46f939823241856ebf1bd)
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 static int spi_post_bind(struct udevice *dev)
112 {
113 	/* Scan the bus for devices */
114 	return dm_scan_fdt_dev(dev);
115 }
116 
117 static int spi_child_post_bind(struct udevice *dev)
118 {
119 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
120 
121 	if (dev->of_offset == -1)
122 		return 0;
123 
124 	return spi_slave_ofdata_to_platdata(gd->fdt_blob, dev->of_offset, plat);
125 }
126 
127 static int spi_post_probe(struct udevice *bus)
128 {
129 	struct dm_spi_bus *spi = dev_get_uclass_priv(bus);
130 
131 	spi->max_hz = fdtdec_get_int(gd->fdt_blob, bus->of_offset,
132 				     "spi-max-frequency", 0);
133 
134 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
135 	struct dm_spi_ops *ops = spi_get_ops(bus);
136 
137 
138 	if (ops->claim_bus)
139 		ops->claim_bus += gd->reloc_off;
140 	if (ops->release_bus)
141 		ops->release_bus += gd->reloc_off;
142 	if (ops->set_wordlen)
143 		ops->set_wordlen += gd->reloc_off;
144 	if (ops->xfer)
145 		ops->xfer += gd->reloc_off;
146 	if (ops->set_speed)
147 		ops->set_speed += gd->reloc_off;
148 	if (ops->set_mode)
149 		ops->set_mode += gd->reloc_off;
150 	if (ops->cs_info)
151 		ops->cs_info += gd->reloc_off;
152 #endif
153 
154 	return 0;
155 }
156 
157 static int spi_child_pre_probe(struct udevice *dev)
158 {
159 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
160 	struct spi_slave *slave = dev_get_parent_priv(dev);
161 
162 	/*
163 	 * This is needed because we pass struct spi_slave around the place
164 	 * instead slave->dev (a struct udevice). So we have to have some
165 	 * way to access the slave udevice given struct spi_slave. Once we
166 	 * change the SPI API to use udevice instead of spi_slave, we can
167 	 * drop this.
168 	 */
169 	slave->dev = dev;
170 
171 	slave->max_hz = plat->max_hz;
172 	slave->mode = plat->mode;
173 	slave->mode_rx = plat->mode_rx;
174 	slave->wordlen = SPI_DEFAULT_WORDLEN;
175 
176 	return 0;
177 }
178 
179 int spi_chip_select(struct udevice *dev)
180 {
181 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
182 
183 	return plat ? plat->cs : -ENOENT;
184 }
185 
186 int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp)
187 {
188 	struct udevice *dev;
189 
190 	for (device_find_first_child(bus, &dev); dev;
191 	     device_find_next_child(&dev)) {
192 		struct dm_spi_slave_platdata *plat;
193 
194 		plat = dev_get_parent_platdata(dev);
195 		debug("%s: plat=%p, cs=%d\n", __func__, plat, plat->cs);
196 		if (plat->cs == cs) {
197 			*devp = dev;
198 			return 0;
199 		}
200 	}
201 
202 	return -ENODEV;
203 }
204 
205 int spi_cs_is_valid(unsigned int busnum, unsigned int cs)
206 {
207 	struct spi_cs_info info;
208 	struct udevice *bus;
209 	int ret;
210 
211 	ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
212 	if (ret) {
213 		debug("%s: No bus %d\n", __func__, busnum);
214 		return ret;
215 	}
216 
217 	return spi_cs_info(bus, cs, &info);
218 }
219 
220 int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info)
221 {
222 	struct spi_cs_info local_info;
223 	struct dm_spi_ops *ops;
224 	int ret;
225 
226 	if (!info)
227 		info = &local_info;
228 
229 	/* If there is a device attached, return it */
230 	info->dev = NULL;
231 	ret = spi_find_chip_select(bus, cs, &info->dev);
232 	if (!ret)
233 		return 0;
234 
235 	/*
236 	 * Otherwise ask the driver. For the moment we don't have CS info.
237 	 * When we do we could provide the driver with a helper function
238 	 * to figure out what chip selects are valid, or just handle the
239 	 * request.
240 	 */
241 	ops = spi_get_ops(bus);
242 	if (ops->cs_info)
243 		return ops->cs_info(bus, cs, info);
244 
245 	/*
246 	 * We could assume there is at least one valid chip select, but best
247 	 * to be sure and return an error in this case. The driver didn't
248 	 * care enough to tell us.
249 	 */
250 	return -ENODEV;
251 }
252 
253 int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
254 			struct udevice **devp)
255 {
256 	struct udevice *bus, *dev;
257 	int ret;
258 
259 	ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
260 	if (ret) {
261 		debug("%s: No bus %d\n", __func__, busnum);
262 		return ret;
263 	}
264 	ret = spi_find_chip_select(bus, cs, &dev);
265 	if (ret) {
266 		debug("%s: No cs %d\n", __func__, cs);
267 		return ret;
268 	}
269 	*busp = bus;
270 	*devp = dev;
271 
272 	return ret;
273 }
274 
275 int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
276 		       const char *drv_name, const char *dev_name,
277 		       struct udevice **busp, struct spi_slave **devp)
278 {
279 	struct udevice *bus, *dev;
280 	struct dm_spi_slave_platdata *plat;
281 	bool created = false;
282 	int ret;
283 
284 	ret = uclass_get_device_by_seq(UCLASS_SPI, busnum, &bus);
285 	if (ret) {
286 		printf("Invalid bus %d (err=%d)\n", busnum, ret);
287 		return ret;
288 	}
289 	ret = spi_find_chip_select(bus, cs, &dev);
290 
291 	/*
292 	 * If there is no such device, create one automatically. This means
293 	 * that we don't need a device tree node or platform data for the
294 	 * SPI flash chip - we will bind to the correct driver.
295 	 */
296 	if (ret == -ENODEV && drv_name) {
297 		debug("%s: Binding new device '%s', busnum=%d, cs=%d, driver=%s\n",
298 		      __func__, dev_name, busnum, cs, drv_name);
299 		ret = device_bind_driver(bus, drv_name, dev_name, &dev);
300 		if (ret)
301 			return ret;
302 		plat = dev_get_parent_platdata(dev);
303 		plat->cs = cs;
304 		plat->max_hz = speed;
305 		plat->mode = mode;
306 		created = true;
307 	} else if (ret) {
308 		printf("Invalid chip select %d:%d (err=%d)\n", busnum, cs,
309 		       ret);
310 		return ret;
311 	}
312 
313 	if (!device_active(dev)) {
314 		struct spi_slave *slave;
315 
316 		ret = device_probe(dev);
317 		if (ret)
318 			goto err;
319 		slave = dev_get_parent_priv(dev);
320 		slave->dev = dev;
321 	}
322 
323 	plat = dev_get_parent_platdata(dev);
324 	if (!speed) {
325 		speed = plat->max_hz;
326 		mode = plat->mode;
327 	}
328 	ret = spi_set_speed_mode(bus, speed, mode);
329 	if (ret)
330 		goto err;
331 
332 	*busp = bus;
333 	*devp = dev_get_parent_priv(dev);
334 	debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp);
335 
336 	return 0;
337 
338 err:
339 	debug("%s: Error path, created=%d, device '%s'\n", __func__,
340 	      created, dev->name);
341 	if (created) {
342 		device_remove(dev);
343 		device_unbind(dev);
344 	}
345 
346 	return ret;
347 }
348 
349 /* Compatibility function - to be removed */
350 struct spi_slave *spi_setup_slave_fdt(const void *blob, int node,
351 				      int bus_node)
352 {
353 	struct udevice *bus, *dev;
354 	int ret;
355 
356 	ret = uclass_get_device_by_of_offset(UCLASS_SPI, bus_node, &bus);
357 	if (ret)
358 		return NULL;
359 	ret = device_get_child_by_of_offset(bus, node, &dev);
360 	if (ret)
361 		return NULL;
362 	return dev_get_parent_priv(dev);
363 }
364 
365 /* Compatibility function - to be removed */
366 struct spi_slave *spi_setup_slave(unsigned int busnum, unsigned int cs,
367 				  unsigned int speed, unsigned int mode)
368 {
369 	struct spi_slave *slave;
370 	struct udevice *dev;
371 	int ret;
372 
373 	ret = spi_get_bus_and_cs(busnum, cs, speed, mode, NULL, 0, &dev,
374 				  &slave);
375 	if (ret)
376 		return NULL;
377 
378 	return slave;
379 }
380 
381 void spi_free_slave(struct spi_slave *slave)
382 {
383 	device_remove(slave->dev);
384 	slave->dev = NULL;
385 }
386 
387 int spi_slave_ofdata_to_platdata(const void *blob, int node,
388 				 struct dm_spi_slave_platdata *plat)
389 {
390 	int mode = 0, mode_rx = 0;
391 	int value;
392 
393 	plat->cs = fdtdec_get_int(blob, node, "reg", -1);
394 	plat->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency", 0);
395 	if (fdtdec_get_bool(blob, node, "spi-cpol"))
396 		mode |= SPI_CPOL;
397 	if (fdtdec_get_bool(blob, node, "spi-cpha"))
398 		mode |= SPI_CPHA;
399 	if (fdtdec_get_bool(blob, node, "spi-cs-high"))
400 		mode |= SPI_CS_HIGH;
401 	if (fdtdec_get_bool(blob, node, "spi-3wire"))
402 		mode |= SPI_3WIRE;
403 	if (fdtdec_get_bool(blob, node, "spi-half-duplex"))
404 		mode |= SPI_PREAMBLE;
405 
406 	/* Device DUAL/QUAD mode */
407 	value = fdtdec_get_uint(blob, node, "spi-tx-bus-width", 1);
408 	switch (value) {
409 	case 1:
410 		break;
411 	case 2:
412 		mode |= SPI_TX_DUAL;
413 		break;
414 	case 4:
415 		mode |= SPI_TX_QUAD;
416 		break;
417 	default:
418 		error("spi-tx-bus-width %d not supported\n", value);
419 		break;
420 	}
421 
422 	plat->mode = mode;
423 
424 	value = fdtdec_get_uint(blob, node, "spi-rx-bus-width", 1);
425 	switch (value) {
426 	case 1:
427 		break;
428 	case 2:
429 		mode_rx |= SPI_RX_DUAL;
430 		break;
431 	case 4:
432 		mode_rx |= SPI_RX_QUAD;
433 		break;
434 	default:
435 		error("spi-rx-bus-width %d not supported\n", value);
436 		break;
437 	}
438 
439 	plat->mode_rx = mode_rx;
440 
441 	return 0;
442 }
443 
444 UCLASS_DRIVER(spi) = {
445 	.id		= UCLASS_SPI,
446 	.name		= "spi",
447 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
448 	.post_bind	= spi_post_bind,
449 	.post_probe	= spi_post_probe,
450 	.child_pre_probe = spi_child_pre_probe,
451 	.per_device_auto_alloc_size = sizeof(struct dm_spi_bus),
452 	.per_child_auto_alloc_size = sizeof(struct spi_slave),
453 	.per_child_platdata_auto_alloc_size =
454 			sizeof(struct dm_spi_slave_platdata),
455 	.child_post_bind = spi_child_post_bind,
456 };
457 
458 UCLASS_DRIVER(spi_generic) = {
459 	.id		= UCLASS_SPI_GENERIC,
460 	.name		= "spi_generic",
461 };
462 
463 U_BOOT_DRIVER(spi_generic_drv) = {
464 	.name		= "spi_generic_drv",
465 	.id		= UCLASS_SPI_GENERIC,
466 };
467