xref: /openbmc/u-boot/drivers/spi/spi-uclass.c (revision fd0bc623)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) 2014 Google, Inc
4  */
5 
6 #include <common.h>
7 #include <dm.h>
8 #include <errno.h>
9 #include <malloc.h>
10 #include <spi.h>
11 #include <dm/device-internal.h>
12 #include <dm/uclass-internal.h>
13 #include <dm/lists.h>
14 #include <dm/util.h>
15 
16 DECLARE_GLOBAL_DATA_PTR;
17 
18 #define SPI_DEFAULT_SPEED_HZ 100000
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 
55 	speed = slave->max_hz;
56 	if (spi->max_hz) {
57 		if (speed)
58 			speed = min(speed, (int)spi->max_hz);
59 		else
60 			speed = spi->max_hz;
61 	}
62 	if (!speed)
63 		speed = SPI_DEFAULT_SPEED_HZ;
64 	if (speed != slave->speed) {
65 		int ret = spi_set_speed_mode(bus, speed, slave->mode);
66 
67 		if (ret)
68 			return log_ret(ret);
69 		slave->speed = speed;
70 	}
71 
72 	return log_ret(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 log_ret(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_valid(dev))
117 		return 0;
118 
119 	return spi_slave_ofdata_to_platdata(dev, plat);
120 }
121 #endif
122 
123 static int spi_post_probe(struct udevice *bus)
124 {
125 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
126 	struct dm_spi_bus *spi = dev_get_uclass_priv(bus);
127 
128 	spi->max_hz = dev_read_u32_default(bus, "spi-max-frequency", 0);
129 #endif
130 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
131 	struct dm_spi_ops *ops = spi_get_ops(bus);
132 
133 	if (ops->claim_bus)
134 		ops->claim_bus += gd->reloc_off;
135 	if (ops->release_bus)
136 		ops->release_bus += gd->reloc_off;
137 	if (ops->set_wordlen)
138 		ops->set_wordlen += gd->reloc_off;
139 	if (ops->xfer)
140 		ops->xfer += gd->reloc_off;
141 	if (ops->set_speed)
142 		ops->set_speed += gd->reloc_off;
143 	if (ops->set_mode)
144 		ops->set_mode += gd->reloc_off;
145 	if (ops->cs_info)
146 		ops->cs_info += gd->reloc_off;
147 #endif
148 
149 	return 0;
150 }
151 
152 static int spi_child_pre_probe(struct udevice *dev)
153 {
154 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
155 	struct spi_slave *slave = dev_get_parent_priv(dev);
156 
157 	/*
158 	 * This is needed because we pass struct spi_slave around the place
159 	 * instead slave->dev (a struct udevice). So we have to have some
160 	 * way to access the slave udevice given struct spi_slave. Once we
161 	 * change the SPI API to use udevice instead of spi_slave, we can
162 	 * drop this.
163 	 */
164 	slave->dev = dev;
165 
166 	slave->max_hz = plat->max_hz;
167 	slave->mode = plat->mode;
168 	slave->wordlen = SPI_DEFAULT_WORDLEN;
169 
170 	return 0;
171 }
172 
173 int spi_chip_select(struct udevice *dev)
174 {
175 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
176 
177 	return plat ? plat->cs : -ENOENT;
178 }
179 
180 int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp)
181 {
182 	struct udevice *dev;
183 
184 	for (device_find_first_child(bus, &dev); dev;
185 	     device_find_next_child(&dev)) {
186 		struct dm_spi_slave_platdata *plat;
187 
188 		plat = dev_get_parent_platdata(dev);
189 		debug("%s: plat=%p, cs=%d\n", __func__, plat, plat->cs);
190 		if (plat->cs == cs) {
191 			*devp = dev;
192 			return 0;
193 		}
194 	}
195 
196 	return -ENODEV;
197 }
198 
199 int spi_cs_is_valid(unsigned int busnum, unsigned int cs)
200 {
201 	struct spi_cs_info info;
202 	struct udevice *bus;
203 	int ret;
204 
205 	ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
206 	if (ret) {
207 		debug("%s: No bus %d\n", __func__, busnum);
208 		return ret;
209 	}
210 
211 	return spi_cs_info(bus, cs, &info);
212 }
213 
214 int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info)
215 {
216 	struct spi_cs_info local_info;
217 	struct dm_spi_ops *ops;
218 	int ret;
219 
220 	if (!info)
221 		info = &local_info;
222 
223 	/* If there is a device attached, return it */
224 	info->dev = NULL;
225 	ret = spi_find_chip_select(bus, cs, &info->dev);
226 	if (!ret)
227 		return 0;
228 
229 	/*
230 	 * Otherwise ask the driver. For the moment we don't have CS info.
231 	 * When we do we could provide the driver with a helper function
232 	 * to figure out what chip selects are valid, or just handle the
233 	 * request.
234 	 */
235 	ops = spi_get_ops(bus);
236 	if (ops->cs_info)
237 		return ops->cs_info(bus, cs, info);
238 
239 	/*
240 	 * We could assume there is at least one valid chip select, but best
241 	 * to be sure and return an error in this case. The driver didn't
242 	 * care enough to tell us.
243 	 */
244 	return -ENODEV;
245 }
246 
247 int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
248 			struct udevice **devp)
249 {
250 	struct udevice *bus, *dev;
251 	int ret;
252 
253 	ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
254 	if (ret) {
255 		debug("%s: No bus %d\n", __func__, busnum);
256 		return ret;
257 	}
258 	ret = spi_find_chip_select(bus, cs, &dev);
259 	if (ret) {
260 		debug("%s: No cs %d\n", __func__, cs);
261 		return ret;
262 	}
263 	*busp = bus;
264 	*devp = dev;
265 
266 	return ret;
267 }
268 
269 int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
270 		       const char *drv_name, const char *dev_name,
271 		       struct udevice **busp, struct spi_slave **devp)
272 {
273 	struct udevice *bus, *dev;
274 	struct dm_spi_slave_platdata *plat;
275 	bool created = false;
276 	int ret;
277 
278 #if CONFIG_IS_ENABLED(OF_PLATDATA) || CONFIG_IS_ENABLED(OF_PRIOR_STAGE)
279 	ret = uclass_first_device_err(UCLASS_SPI, &bus);
280 #else
281 	ret = uclass_get_device_by_seq(UCLASS_SPI, busnum, &bus);
282 #endif
283 	if (ret) {
284 		printf("Invalid bus %d (err=%d)\n", busnum, ret);
285 		return ret;
286 	}
287 	ret = spi_find_chip_select(bus, cs, &dev);
288 
289 	/*
290 	 * If there is no such device, create one automatically. This means
291 	 * that we don't need a device tree node or platform data for the
292 	 * SPI flash chip - we will bind to the correct driver.
293 	 */
294 	if (ret == -ENODEV && drv_name) {
295 		debug("%s: Binding new device '%s', busnum=%d, cs=%d, driver=%s\n",
296 		      __func__, dev_name, busnum, cs, drv_name);
297 		ret = device_bind_driver(bus, drv_name, dev_name, &dev);
298 		if (ret) {
299 			debug("%s: Unable to bind driver (ret=%d)\n", __func__,
300 			      ret);
301 			return ret;
302 		}
303 		plat = dev_get_parent_platdata(dev);
304 		plat->cs = cs;
305 		if (speed) {
306 			plat->max_hz = speed;
307 		} else {
308 			printf("Warning: SPI speed fallback to %u kHz\n",
309 			       SPI_DEFAULT_SPEED_HZ / 1000);
310 			plat->max_hz = SPI_DEFAULT_SPEED_HZ;
311 		}
312 		plat->mode = mode;
313 		created = true;
314 	} else if (ret) {
315 		printf("Invalid chip select %d:%d (err=%d)\n", busnum, cs,
316 		       ret);
317 		return ret;
318 	}
319 
320 	if (!device_active(dev)) {
321 		struct spi_slave *slave;
322 
323 		ret = device_probe(dev);
324 		if (ret)
325 			goto err;
326 		slave = dev_get_parent_priv(dev);
327 		slave->dev = dev;
328 	}
329 
330 	plat = dev_get_parent_platdata(dev);
331 	if (!speed) {
332 		speed = plat->max_hz;
333 		mode = plat->mode;
334 	}
335 	ret = spi_set_speed_mode(bus, speed, mode);
336 	if (ret)
337 		goto err;
338 
339 	*busp = bus;
340 	*devp = dev_get_parent_priv(dev);
341 	debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp);
342 
343 	return 0;
344 
345 err:
346 	debug("%s: Error path, created=%d, device '%s'\n", __func__,
347 	      created, dev->name);
348 	if (created) {
349 		device_remove(dev, DM_REMOVE_NORMAL);
350 		device_unbind(dev);
351 	}
352 
353 	return ret;
354 }
355 
356 /* Compatibility function - to be removed */
357 struct spi_slave *spi_setup_slave(unsigned int busnum, unsigned int cs,
358 				  unsigned int speed, unsigned int mode)
359 {
360 	struct spi_slave *slave;
361 	struct udevice *dev;
362 	int ret;
363 
364 	ret = spi_get_bus_and_cs(busnum, cs, speed, mode, NULL, 0, &dev,
365 				 &slave);
366 	if (ret)
367 		return NULL;
368 
369 	return slave;
370 }
371 
372 void spi_free_slave(struct spi_slave *slave)
373 {
374 	device_remove(slave->dev, DM_REMOVE_NORMAL);
375 	slave->dev = NULL;
376 }
377 
378 int spi_slave_ofdata_to_platdata(struct udevice *dev,
379 				 struct dm_spi_slave_platdata *plat)
380 {
381 	int mode = 0;
382 	int value;
383 
384 	plat->cs = dev_read_u32_default(dev, "reg", -1);
385 	plat->max_hz = dev_read_u32_default(dev, "spi-max-frequency",
386 					    SPI_DEFAULT_SPEED_HZ);
387 	if (dev_read_bool(dev, "spi-cpol"))
388 		mode |= SPI_CPOL;
389 	if (dev_read_bool(dev, "spi-cpha"))
390 		mode |= SPI_CPHA;
391 	if (dev_read_bool(dev, "spi-cs-high"))
392 		mode |= SPI_CS_HIGH;
393 	if (dev_read_bool(dev, "spi-3wire"))
394 		mode |= SPI_3WIRE;
395 	if (dev_read_bool(dev, "spi-half-duplex"))
396 		mode |= SPI_PREAMBLE;
397 
398 	/* Device DUAL/QUAD mode */
399 	value = dev_read_u32_default(dev, "spi-tx-bus-width", 1);
400 	switch (value) {
401 	case 1:
402 		break;
403 	case 2:
404 		mode |= SPI_TX_DUAL;
405 		break;
406 	case 4:
407 		mode |= SPI_TX_QUAD;
408 		break;
409 	default:
410 		warn_non_spl("spi-tx-bus-width %d not supported\n", value);
411 		break;
412 	}
413 
414 	value = dev_read_u32_default(dev, "spi-rx-bus-width", 1);
415 	switch (value) {
416 	case 1:
417 		break;
418 	case 2:
419 		mode |= SPI_RX_DUAL;
420 		break;
421 	case 4:
422 		mode |= SPI_RX_QUAD;
423 		break;
424 	default:
425 		warn_non_spl("spi-rx-bus-width %d not supported\n", value);
426 		break;
427 	}
428 
429 	plat->mode = mode;
430 
431 	return 0;
432 }
433 
434 UCLASS_DRIVER(spi) = {
435 	.id		= UCLASS_SPI,
436 	.name		= "spi",
437 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
438 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
439 	.post_bind	= dm_scan_fdt_dev,
440 #endif
441 	.post_probe	= spi_post_probe,
442 	.child_pre_probe = spi_child_pre_probe,
443 	.per_device_auto_alloc_size = sizeof(struct dm_spi_bus),
444 	.per_child_auto_alloc_size = sizeof(struct spi_slave),
445 	.per_child_platdata_auto_alloc_size =
446 			sizeof(struct dm_spi_slave_platdata),
447 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
448 	.child_post_bind = spi_child_post_bind,
449 #endif
450 };
451 
452 UCLASS_DRIVER(spi_generic) = {
453 	.id		= UCLASS_SPI_GENERIC,
454 	.name		= "spi_generic",
455 };
456 
457 U_BOOT_DRIVER(spi_generic_drv) = {
458 	.name		= "spi_generic_drv",
459 	.id		= UCLASS_SPI_GENERIC,
460 };
461