xref: /openbmc/u-boot/drivers/spi/spi-uclass.c (revision 7f0e8f7b)
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_child_post_bind(struct udevice *dev)
112 {
113 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
114 
115 	if (dev->of_offset == -1)
116 		return 0;
117 
118 	return spi_slave_ofdata_to_platdata(gd->fdt_blob, dev->of_offset, plat);
119 }
120 
121 static int spi_post_probe(struct udevice *bus)
122 {
123 	struct dm_spi_bus *spi = dev_get_uclass_priv(bus);
124 
125 	spi->max_hz = fdtdec_get_int(gd->fdt_blob, bus->of_offset,
126 				     "spi-max-frequency", 0);
127 
128 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
129 	struct dm_spi_ops *ops = spi_get_ops(bus);
130 
131 
132 	if (ops->claim_bus)
133 		ops->claim_bus += gd->reloc_off;
134 	if (ops->release_bus)
135 		ops->release_bus += gd->reloc_off;
136 	if (ops->set_wordlen)
137 		ops->set_wordlen += gd->reloc_off;
138 	if (ops->xfer)
139 		ops->xfer += gd->reloc_off;
140 	if (ops->set_speed)
141 		ops->set_speed += gd->reloc_off;
142 	if (ops->set_mode)
143 		ops->set_mode += gd->reloc_off;
144 	if (ops->cs_info)
145 		ops->cs_info += gd->reloc_off;
146 #endif
147 
148 	return 0;
149 }
150 
151 static int spi_child_pre_probe(struct udevice *dev)
152 {
153 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
154 	struct spi_slave *slave = dev_get_parent_priv(dev);
155 
156 	/*
157 	 * This is needed because we pass struct spi_slave around the place
158 	 * instead slave->dev (a struct udevice). So we have to have some
159 	 * way to access the slave udevice given struct spi_slave. Once we
160 	 * change the SPI API to use udevice instead of spi_slave, we can
161 	 * drop this.
162 	 */
163 	slave->dev = dev;
164 
165 	slave->max_hz = plat->max_hz;
166 	slave->mode = plat->mode;
167 	slave->wordlen = SPI_DEFAULT_WORDLEN;
168 
169 	return 0;
170 }
171 
172 int spi_chip_select(struct udevice *dev)
173 {
174 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
175 
176 	return plat ? plat->cs : -ENOENT;
177 }
178 
179 int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp)
180 {
181 	struct udevice *dev;
182 
183 	for (device_find_first_child(bus, &dev); dev;
184 	     device_find_next_child(&dev)) {
185 		struct dm_spi_slave_platdata *plat;
186 
187 		plat = dev_get_parent_platdata(dev);
188 		debug("%s: plat=%p, cs=%d\n", __func__, plat, plat->cs);
189 		if (plat->cs == cs) {
190 			*devp = dev;
191 			return 0;
192 		}
193 	}
194 
195 	return -ENODEV;
196 }
197 
198 int spi_cs_is_valid(unsigned int busnum, unsigned int cs)
199 {
200 	struct spi_cs_info info;
201 	struct udevice *bus;
202 	int ret;
203 
204 	ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
205 	if (ret) {
206 		debug("%s: No bus %d\n", __func__, busnum);
207 		return ret;
208 	}
209 
210 	return spi_cs_info(bus, cs, &info);
211 }
212 
213 int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info)
214 {
215 	struct spi_cs_info local_info;
216 	struct dm_spi_ops *ops;
217 	int ret;
218 
219 	if (!info)
220 		info = &local_info;
221 
222 	/* If there is a device attached, return it */
223 	info->dev = NULL;
224 	ret = spi_find_chip_select(bus, cs, &info->dev);
225 	if (!ret)
226 		return 0;
227 
228 	/*
229 	 * Otherwise ask the driver. For the moment we don't have CS info.
230 	 * When we do we could provide the driver with a helper function
231 	 * to figure out what chip selects are valid, or just handle the
232 	 * request.
233 	 */
234 	ops = spi_get_ops(bus);
235 	if (ops->cs_info)
236 		return ops->cs_info(bus, cs, info);
237 
238 	/*
239 	 * We could assume there is at least one valid chip select, but best
240 	 * to be sure and return an error in this case. The driver didn't
241 	 * care enough to tell us.
242 	 */
243 	return -ENODEV;
244 }
245 
246 int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
247 			struct udevice **devp)
248 {
249 	struct udevice *bus, *dev;
250 	int ret;
251 
252 	ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
253 	if (ret) {
254 		debug("%s: No bus %d\n", __func__, busnum);
255 		return ret;
256 	}
257 	ret = spi_find_chip_select(bus, cs, &dev);
258 	if (ret) {
259 		debug("%s: No cs %d\n", __func__, cs);
260 		return ret;
261 	}
262 	*busp = bus;
263 	*devp = dev;
264 
265 	return ret;
266 }
267 
268 int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
269 		       const char *drv_name, const char *dev_name,
270 		       struct udevice **busp, struct spi_slave **devp)
271 {
272 	struct udevice *bus, *dev;
273 	struct dm_spi_slave_platdata *plat;
274 	bool created = false;
275 	int ret;
276 
277 	ret = uclass_get_device_by_seq(UCLASS_SPI, busnum, &bus);
278 	if (ret) {
279 		printf("Invalid bus %d (err=%d)\n", busnum, ret);
280 		return ret;
281 	}
282 	ret = spi_find_chip_select(bus, cs, &dev);
283 
284 	/*
285 	 * If there is no such device, create one automatically. This means
286 	 * that we don't need a device tree node or platform data for the
287 	 * SPI flash chip - we will bind to the correct driver.
288 	 */
289 	if (ret == -ENODEV && drv_name) {
290 		debug("%s: Binding new device '%s', busnum=%d, cs=%d, driver=%s\n",
291 		      __func__, dev_name, busnum, cs, drv_name);
292 		ret = device_bind_driver(bus, drv_name, dev_name, &dev);
293 		if (ret)
294 			return ret;
295 		plat = dev_get_parent_platdata(dev);
296 		plat->cs = cs;
297 		plat->max_hz = speed;
298 		plat->mode = mode;
299 		created = true;
300 	} else if (ret) {
301 		printf("Invalid chip select %d:%d (err=%d)\n", busnum, cs,
302 		       ret);
303 		return ret;
304 	}
305 
306 	if (!device_active(dev)) {
307 		struct spi_slave *slave;
308 
309 		ret = device_probe(dev);
310 		if (ret)
311 			goto err;
312 		slave = dev_get_parent_priv(dev);
313 		slave->dev = dev;
314 	}
315 
316 	plat = dev_get_parent_platdata(dev);
317 	if (!speed) {
318 		speed = plat->max_hz;
319 		mode = plat->mode;
320 	}
321 	ret = spi_set_speed_mode(bus, speed, mode);
322 	if (ret)
323 		goto err;
324 
325 	*busp = bus;
326 	*devp = dev_get_parent_priv(dev);
327 	debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp);
328 
329 	return 0;
330 
331 err:
332 	debug("%s: Error path, created=%d, device '%s'\n", __func__,
333 	      created, dev->name);
334 	if (created) {
335 		device_remove(dev);
336 		device_unbind(dev);
337 	}
338 
339 	return ret;
340 }
341 
342 /* Compatibility function - to be removed */
343 struct spi_slave *spi_setup_slave_fdt(const void *blob, int node,
344 				      int bus_node)
345 {
346 	struct udevice *bus, *dev;
347 	int ret;
348 
349 	ret = uclass_get_device_by_of_offset(UCLASS_SPI, bus_node, &bus);
350 	if (ret)
351 		return NULL;
352 	ret = device_get_child_by_of_offset(bus, node, &dev);
353 	if (ret)
354 		return NULL;
355 	return dev_get_parent_priv(dev);
356 }
357 
358 /* Compatibility function - to be removed */
359 struct spi_slave *spi_setup_slave(unsigned int busnum, unsigned int cs,
360 				  unsigned int speed, unsigned int mode)
361 {
362 	struct spi_slave *slave;
363 	struct udevice *dev;
364 	int ret;
365 
366 	ret = spi_get_bus_and_cs(busnum, cs, speed, mode, NULL, 0, &dev,
367 				  &slave);
368 	if (ret)
369 		return NULL;
370 
371 	return slave;
372 }
373 
374 void spi_free_slave(struct spi_slave *slave)
375 {
376 	device_remove(slave->dev);
377 	slave->dev = NULL;
378 }
379 
380 int spi_slave_ofdata_to_platdata(const void *blob, int node,
381 				 struct dm_spi_slave_platdata *plat)
382 {
383 	int mode = 0;
384 	int value;
385 
386 	plat->cs = fdtdec_get_int(blob, node, "reg", -1);
387 	plat->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency", 0);
388 	if (fdtdec_get_bool(blob, node, "spi-cpol"))
389 		mode |= SPI_CPOL;
390 	if (fdtdec_get_bool(blob, node, "spi-cpha"))
391 		mode |= SPI_CPHA;
392 	if (fdtdec_get_bool(blob, node, "spi-cs-high"))
393 		mode |= SPI_CS_HIGH;
394 	if (fdtdec_get_bool(blob, node, "spi-3wire"))
395 		mode |= SPI_3WIRE;
396 	if (fdtdec_get_bool(blob, node, "spi-half-duplex"))
397 		mode |= SPI_PREAMBLE;
398 
399 	/* Device DUAL/QUAD mode */
400 	value = fdtdec_get_uint(blob, node, "spi-tx-bus-width", 1);
401 	switch (value) {
402 	case 1:
403 		break;
404 	case 2:
405 		mode |= SPI_TX_DUAL;
406 		break;
407 	case 4:
408 		mode |= SPI_TX_QUAD;
409 		break;
410 	default:
411 		error("spi-tx-bus-width %d not supported\n", value);
412 		break;
413 	}
414 
415 	value = fdtdec_get_uint(blob, node, "spi-rx-bus-width", 1);
416 	switch (value) {
417 	case 1:
418 		break;
419 	case 2:
420 		mode |= SPI_RX_DUAL;
421 		break;
422 	case 4:
423 		mode |= SPI_RX_QUAD;
424 		break;
425 	default:
426 		error("spi-rx-bus-width %d not supported\n", value);
427 		break;
428 	}
429 
430 	plat->mode = mode;
431 
432 	return 0;
433 }
434 
435 UCLASS_DRIVER(spi) = {
436 	.id		= UCLASS_SPI,
437 	.name		= "spi",
438 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
439 	.post_bind	= dm_scan_fdt_dev,
440 	.post_probe	= spi_post_probe,
441 	.child_pre_probe = spi_child_pre_probe,
442 	.per_device_auto_alloc_size = sizeof(struct dm_spi_bus),
443 	.per_child_auto_alloc_size = sizeof(struct spi_slave),
444 	.per_child_platdata_auto_alloc_size =
445 			sizeof(struct dm_spi_slave_platdata),
446 	.child_post_bind = spi_child_post_bind,
447 };
448 
449 UCLASS_DRIVER(spi_generic) = {
450 	.id		= UCLASS_SPI_GENERIC,
451 	.name		= "spi_generic",
452 };
453 
454 U_BOOT_DRIVER(spi_generic_drv) = {
455 	.name		= "spi_generic_drv",
456 	.id		= UCLASS_SPI_GENERIC,
457 };
458