xref: /openbmc/u-boot/drivers/spi/spi-uclass.c (revision ed4708aa)
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/root.h>
16 #include <dm/lists.h>
17 #include <dm/util.h>
18 
19 DECLARE_GLOBAL_DATA_PTR;
20 
21 static int spi_set_speed_mode(struct udevice *bus, int speed, int mode)
22 {
23 	struct dm_spi_ops *ops;
24 	int ret;
25 
26 	ops = spi_get_ops(bus);
27 	if (ops->set_speed)
28 		ret = ops->set_speed(bus, speed);
29 	else
30 		ret = -EINVAL;
31 	if (ret) {
32 		printf("Cannot set speed (err=%d)\n", ret);
33 		return ret;
34 	}
35 
36 	if (ops->set_mode)
37 		ret = ops->set_mode(bus, mode);
38 	else
39 		ret = -EINVAL;
40 	if (ret) {
41 		printf("Cannot set mode (err=%d)\n", ret);
42 		return ret;
43 	}
44 
45 	return 0;
46 }
47 
48 int dm_spi_claim_bus(struct udevice *dev)
49 {
50 	struct udevice *bus = dev->parent;
51 	struct dm_spi_ops *ops = spi_get_ops(bus);
52 	struct dm_spi_bus *spi = dev_get_uclass_priv(bus);
53 	struct spi_slave *slave = dev_get_parent_priv(dev);
54 	int speed;
55 	int ret;
56 
57 	speed = slave->max_hz;
58 	if (spi->max_hz) {
59 		if (speed)
60 			speed = min(speed, (int)spi->max_hz);
61 		else
62 			speed = spi->max_hz;
63 	}
64 	if (!speed)
65 		speed = 100000;
66 	if (speed != slave->speed) {
67 		ret = spi_set_speed_mode(bus, speed, slave->mode);
68 		if (ret)
69 			return ret;
70 		slave->speed = speed;
71 	}
72 
73 	return ops->claim_bus ? ops->claim_bus(dev) : 0;
74 }
75 
76 void dm_spi_release_bus(struct udevice *dev)
77 {
78 	struct udevice *bus = dev->parent;
79 	struct dm_spi_ops *ops = spi_get_ops(bus);
80 
81 	if (ops->release_bus)
82 		ops->release_bus(dev);
83 }
84 
85 int dm_spi_xfer(struct udevice *dev, unsigned int bitlen,
86 		const void *dout, void *din, unsigned long flags)
87 {
88 	struct udevice *bus = dev->parent;
89 
90 	if (bus->uclass->uc_drv->id != UCLASS_SPI)
91 		return -EOPNOTSUPP;
92 
93 	return spi_get_ops(bus)->xfer(dev, bitlen, dout, din, flags);
94 }
95 
96 int spi_claim_bus(struct spi_slave *slave)
97 {
98 	return dm_spi_claim_bus(slave->dev);
99 }
100 
101 void spi_release_bus(struct spi_slave *slave)
102 {
103 	dm_spi_release_bus(slave->dev);
104 }
105 
106 int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
107 	     const void *dout, void *din, unsigned long flags)
108 {
109 	return dm_spi_xfer(slave->dev, bitlen, dout, din, flags);
110 }
111 
112 static int spi_post_bind(struct udevice *dev)
113 {
114 	/* Scan the bus for devices */
115 	return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
116 }
117 
118 static int spi_child_post_bind(struct udevice *dev)
119 {
120 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
121 
122 	if (dev->of_offset == -1)
123 		return 0;
124 
125 	return spi_slave_ofdata_to_platdata(gd->fdt_blob, dev->of_offset, plat);
126 }
127 
128 static int spi_post_probe(struct udevice *bus)
129 {
130 	struct dm_spi_bus *spi = dev_get_uclass_priv(bus);
131 
132 	spi->max_hz = fdtdec_get_int(gd->fdt_blob, bus->of_offset,
133 				     "spi-max-frequency", 0);
134 
135 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
136 	struct dm_spi_ops *ops = spi_get_ops(bus);
137 
138 
139 	if (ops->claim_bus)
140 		ops->claim_bus += gd->reloc_off;
141 	if (ops->release_bus)
142 		ops->release_bus += gd->reloc_off;
143 	if (ops->set_wordlen)
144 		ops->set_wordlen += gd->reloc_off;
145 	if (ops->xfer)
146 		ops->xfer += gd->reloc_off;
147 	if (ops->set_speed)
148 		ops->set_speed += gd->reloc_off;
149 	if (ops->set_mode)
150 		ops->set_mode += gd->reloc_off;
151 	if (ops->cs_info)
152 		ops->cs_info += gd->reloc_off;
153 #endif
154 
155 	return 0;
156 }
157 
158 static int spi_child_pre_probe(struct udevice *dev)
159 {
160 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
161 	struct spi_slave *slave = dev_get_parent_priv(dev);
162 
163 	/*
164 	 * This is needed because we pass struct spi_slave around the place
165 	 * instead slave->dev (a struct udevice). So we have to have some
166 	 * way to access the slave udevice given struct spi_slave. Once we
167 	 * change the SPI API to use udevice instead of spi_slave, we can
168 	 * drop this.
169 	 */
170 	slave->dev = dev;
171 
172 	slave->max_hz = plat->max_hz;
173 	slave->mode = plat->mode;
174 	slave->mode_rx = plat->mode_rx;
175 	slave->wordlen = SPI_DEFAULT_WORDLEN;
176 
177 	return 0;
178 }
179 
180 int spi_chip_select(struct udevice *dev)
181 {
182 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
183 
184 	return plat ? plat->cs : -ENOENT;
185 }
186 
187 int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp)
188 {
189 	struct udevice *dev;
190 
191 	for (device_find_first_child(bus, &dev); dev;
192 	     device_find_next_child(&dev)) {
193 		struct dm_spi_slave_platdata *plat;
194 
195 		plat = dev_get_parent_platdata(dev);
196 		debug("%s: plat=%p, cs=%d\n", __func__, plat, plat->cs);
197 		if (plat->cs == cs) {
198 			*devp = dev;
199 			return 0;
200 		}
201 	}
202 
203 	return -ENODEV;
204 }
205 
206 int spi_cs_is_valid(unsigned int busnum, unsigned int cs)
207 {
208 	struct spi_cs_info info;
209 	struct udevice *bus;
210 	int ret;
211 
212 	ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
213 	if (ret) {
214 		debug("%s: No bus %d\n", __func__, busnum);
215 		return ret;
216 	}
217 
218 	return spi_cs_info(bus, cs, &info);
219 }
220 
221 int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info)
222 {
223 	struct spi_cs_info local_info;
224 	struct dm_spi_ops *ops;
225 	int ret;
226 
227 	if (!info)
228 		info = &local_info;
229 
230 	/* If there is a device attached, return it */
231 	info->dev = NULL;
232 	ret = spi_find_chip_select(bus, cs, &info->dev);
233 	if (!ret)
234 		return 0;
235 
236 	/*
237 	 * Otherwise ask the driver. For the moment we don't have CS info.
238 	 * When we do we could provide the driver with a helper function
239 	 * to figure out what chip selects are valid, or just handle the
240 	 * request.
241 	 */
242 	ops = spi_get_ops(bus);
243 	if (ops->cs_info)
244 		return ops->cs_info(bus, cs, info);
245 
246 	/*
247 	 * We could assume there is at least one valid chip select, but best
248 	 * to be sure and return an error in this case. The driver didn't
249 	 * care enough to tell us.
250 	 */
251 	return -ENODEV;
252 }
253 
254 int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
255 			struct udevice **devp)
256 {
257 	struct udevice *bus, *dev;
258 	int ret;
259 
260 	ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
261 	if (ret) {
262 		debug("%s: No bus %d\n", __func__, busnum);
263 		return ret;
264 	}
265 	ret = spi_find_chip_select(bus, cs, &dev);
266 	if (ret) {
267 		debug("%s: No cs %d\n", __func__, cs);
268 		return ret;
269 	}
270 	*busp = bus;
271 	*devp = dev;
272 
273 	return ret;
274 }
275 
276 int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
277 		       const char *drv_name, const char *dev_name,
278 		       struct udevice **busp, struct spi_slave **devp)
279 {
280 	struct udevice *bus, *dev;
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 		struct dm_spi_slave_platdata *plat;
298 
299 		debug("%s: Binding new device '%s', busnum=%d, cs=%d, driver=%s\n",
300 		      __func__, dev_name, busnum, cs, drv_name);
301 		ret = device_bind_driver(bus, drv_name, dev_name, &dev);
302 		if (ret)
303 			return ret;
304 		plat = dev_get_parent_platdata(dev);
305 		plat->cs = cs;
306 		plat->max_hz = speed;
307 		plat->mode = mode;
308 		created = true;
309 	} else if (ret) {
310 		printf("Invalid chip select %d:%d (err=%d)\n", busnum, cs,
311 		       ret);
312 		return ret;
313 	}
314 
315 	if (!device_active(dev)) {
316 		struct spi_slave *slave;
317 
318 		ret = device_probe(dev);
319 		if (ret)
320 			goto err;
321 		slave = dev_get_parent_priv(dev);
322 		slave->dev = dev;
323 	}
324 
325 	ret = spi_set_speed_mode(bus, speed, mode);
326 	if (ret)
327 		goto err;
328 
329 	*busp = bus;
330 	*devp = dev_get_parent_priv(dev);
331 	debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp);
332 
333 	return 0;
334 
335 err:
336 	debug("%s: Error path, credted=%d, device '%s'\n", __func__,
337 	      created, dev->name);
338 	if (created) {
339 		device_remove(dev);
340 		device_unbind(dev);
341 	}
342 
343 	return ret;
344 }
345 
346 /* Compatibility function - to be removed */
347 struct spi_slave *spi_setup_slave_fdt(const void *blob, int node,
348 				      int bus_node)
349 {
350 	struct udevice *bus, *dev;
351 	int ret;
352 
353 	ret = uclass_get_device_by_of_offset(UCLASS_SPI, bus_node, &bus);
354 	if (ret)
355 		return NULL;
356 	ret = device_get_child_by_of_offset(bus, node, &dev);
357 	if (ret)
358 		return NULL;
359 	return dev_get_parent_priv(dev);
360 }
361 
362 /* Compatibility function - to be removed */
363 struct spi_slave *spi_setup_slave(unsigned int busnum, unsigned int cs,
364 				  unsigned int speed, unsigned int mode)
365 {
366 	struct spi_slave *slave;
367 	struct udevice *dev;
368 	int ret;
369 
370 	ret = spi_get_bus_and_cs(busnum, cs, speed, mode, NULL, 0, &dev,
371 				  &slave);
372 	if (ret)
373 		return NULL;
374 
375 	return slave;
376 }
377 
378 void spi_free_slave(struct spi_slave *slave)
379 {
380 	device_remove(slave->dev);
381 	slave->dev = NULL;
382 }
383 
384 int spi_slave_ofdata_to_platdata(const void *blob, int node,
385 				 struct dm_spi_slave_platdata *plat)
386 {
387 	int mode = 0, mode_rx = 0;
388 	int value;
389 
390 	plat->cs = fdtdec_get_int(blob, node, "reg", -1);
391 	plat->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency", 0);
392 	if (fdtdec_get_bool(blob, node, "spi-cpol"))
393 		mode |= SPI_CPOL;
394 	if (fdtdec_get_bool(blob, node, "spi-cpha"))
395 		mode |= SPI_CPHA;
396 	if (fdtdec_get_bool(blob, node, "spi-cs-high"))
397 		mode |= SPI_CS_HIGH;
398 	if (fdtdec_get_bool(blob, node, "spi-3wire"))
399 		mode |= SPI_3WIRE;
400 	if (fdtdec_get_bool(blob, node, "spi-half-duplex"))
401 		mode |= SPI_PREAMBLE;
402 
403 	/* Device DUAL/QUAD mode */
404 	value = fdtdec_get_uint(blob, node, "spi-tx-bus-width", 1);
405 	switch (value) {
406 	case 1:
407 		break;
408 	case 2:
409 		mode |= SPI_TX_DUAL;
410 		break;
411 	case 4:
412 		mode |= SPI_TX_QUAD;
413 		break;
414 	default:
415 		error("spi-tx-bus-width %d not supported\n", value);
416 		break;
417 	}
418 
419 	plat->mode = mode;
420 
421 	value = fdtdec_get_uint(blob, node, "spi-rx-bus-width", 1);
422 	switch (value) {
423 	case 1:
424 		break;
425 	case 2:
426 		mode_rx |= SPI_RX_DUAL;
427 		break;
428 	case 4:
429 		mode_rx |= SPI_RX_QUAD;
430 		break;
431 	default:
432 		error("spi-rx-bus-width %d not supported\n", value);
433 		break;
434 	}
435 
436 	plat->mode_rx = mode_rx;
437 
438 	return 0;
439 }
440 
441 UCLASS_DRIVER(spi) = {
442 	.id		= UCLASS_SPI,
443 	.name		= "spi",
444 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
445 	.post_bind	= spi_post_bind,
446 	.post_probe	= spi_post_probe,
447 	.child_pre_probe = spi_child_pre_probe,
448 	.per_device_auto_alloc_size = sizeof(struct dm_spi_bus),
449 	.per_child_auto_alloc_size = sizeof(struct spi_slave),
450 	.per_child_platdata_auto_alloc_size =
451 			sizeof(struct dm_spi_slave_platdata),
452 	.child_post_bind = spi_child_post_bind,
453 };
454 
455 UCLASS_DRIVER(spi_generic) = {
456 	.id		= UCLASS_SPI_GENERIC,
457 	.name		= "spi_generic",
458 };
459 
460 U_BOOT_DRIVER(spi_generic_drv) = {
461 	.name		= "spi_generic_drv",
462 	.id		= UCLASS_SPI_GENERIC,
463 };
464