xref: /openbmc/u-boot/drivers/spi/spi-uclass.c (revision 00a457b2)
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 spi_claim_bus(struct spi_slave *slave)
49 {
50 	struct udevice *dev = slave->dev;
51 	struct udevice *bus = dev->parent;
52 	struct dm_spi_ops *ops = spi_get_ops(bus);
53 	struct dm_spi_bus *spi = dev_get_uclass_priv(bus);
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 spi_release_bus(struct spi_slave *slave)
77 {
78 	struct udevice *dev = slave->dev;
79 	struct udevice *bus = dev->parent;
80 	struct dm_spi_ops *ops = spi_get_ops(bus);
81 
82 	if (ops->release_bus)
83 		ops->release_bus(dev);
84 }
85 
86 int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
87 	     const void *dout, void *din, unsigned long flags)
88 {
89 	struct udevice *dev = slave->dev;
90 	struct udevice *bus = dev->parent;
91 
92 	if (bus->uclass->uc_drv->id != UCLASS_SPI)
93 		return -EOPNOTSUPP;
94 
95 	return spi_get_ops(bus)->xfer(dev, bitlen, dout, din, flags);
96 }
97 
98 static int spi_post_bind(struct udevice *dev)
99 {
100 	/* Scan the bus for devices */
101 	return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
102 }
103 
104 static int spi_child_post_bind(struct udevice *dev)
105 {
106 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
107 
108 	if (dev->of_offset == -1)
109 		return 0;
110 
111 	return spi_slave_ofdata_to_platdata(gd->fdt_blob, dev->of_offset, plat);
112 }
113 
114 static int spi_post_probe(struct udevice *bus)
115 {
116 	struct dm_spi_bus *spi = dev_get_uclass_priv(bus);
117 
118 	spi->max_hz = fdtdec_get_int(gd->fdt_blob, bus->of_offset,
119 				     "spi-max-frequency", 0);
120 
121 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
122 	struct dm_spi_ops *ops = spi_get_ops(bus);
123 
124 
125 	if (ops->claim_bus)
126 		ops->claim_bus += gd->reloc_off;
127 	if (ops->release_bus)
128 		ops->release_bus += gd->reloc_off;
129 	if (ops->set_wordlen)
130 		ops->set_wordlen += gd->reloc_off;
131 	if (ops->xfer)
132 		ops->xfer += gd->reloc_off;
133 	if (ops->set_speed)
134 		ops->set_speed += gd->reloc_off;
135 	if (ops->set_mode)
136 		ops->set_mode += gd->reloc_off;
137 	if (ops->cs_info)
138 		ops->cs_info += gd->reloc_off;
139 #endif
140 
141 	return 0;
142 }
143 
144 static int spi_child_pre_probe(struct udevice *dev)
145 {
146 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
147 	struct spi_slave *slave = dev_get_parent_priv(dev);
148 
149 	/*
150 	 * This is needed because we pass struct spi_slave around the place
151 	 * instead slave->dev (a struct udevice). So we have to have some
152 	 * way to access the slave udevice given struct spi_slave. Once we
153 	 * change the SPI API to use udevice instead of spi_slave, we can
154 	 * drop this.
155 	 */
156 	slave->dev = dev;
157 
158 	slave->max_hz = plat->max_hz;
159 	slave->mode = plat->mode;
160 	slave->mode_rx = plat->mode_rx;
161 
162 	return 0;
163 }
164 
165 int spi_chip_select(struct udevice *dev)
166 {
167 	struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
168 
169 	return plat ? plat->cs : -ENOENT;
170 }
171 
172 int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp)
173 {
174 	struct udevice *dev;
175 
176 	for (device_find_first_child(bus, &dev); dev;
177 	     device_find_next_child(&dev)) {
178 		struct dm_spi_slave_platdata *plat;
179 
180 		plat = dev_get_parent_platdata(dev);
181 		debug("%s: plat=%p, cs=%d\n", __func__, plat, plat->cs);
182 		if (plat->cs == cs) {
183 			*devp = dev;
184 			return 0;
185 		}
186 	}
187 
188 	return -ENODEV;
189 }
190 
191 int spi_cs_is_valid(unsigned int busnum, unsigned int cs)
192 {
193 	struct spi_cs_info info;
194 	struct udevice *bus;
195 	int ret;
196 
197 	ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
198 	if (ret) {
199 		debug("%s: No bus %d\n", __func__, busnum);
200 		return ret;
201 	}
202 
203 	return spi_cs_info(bus, cs, &info);
204 }
205 
206 int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info)
207 {
208 	struct spi_cs_info local_info;
209 	struct dm_spi_ops *ops;
210 	int ret;
211 
212 	if (!info)
213 		info = &local_info;
214 
215 	/* If there is a device attached, return it */
216 	info->dev = NULL;
217 	ret = spi_find_chip_select(bus, cs, &info->dev);
218 	if (!ret)
219 		return 0;
220 
221 	/*
222 	 * Otherwise ask the driver. For the moment we don't have CS info.
223 	 * When we do we could provide the driver with a helper function
224 	 * to figure out what chip selects are valid, or just handle the
225 	 * request.
226 	 */
227 	ops = spi_get_ops(bus);
228 	if (ops->cs_info)
229 		return ops->cs_info(bus, cs, info);
230 
231 	/*
232 	 * We could assume there is at least one valid chip select, but best
233 	 * to be sure and return an error in this case. The driver didn't
234 	 * care enough to tell us.
235 	 */
236 	return -ENODEV;
237 }
238 
239 int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
240 			struct udevice **devp)
241 {
242 	struct udevice *bus, *dev;
243 	int ret;
244 
245 	ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
246 	if (ret) {
247 		debug("%s: No bus %d\n", __func__, busnum);
248 		return ret;
249 	}
250 	ret = spi_find_chip_select(bus, cs, &dev);
251 	if (ret) {
252 		debug("%s: No cs %d\n", __func__, cs);
253 		return ret;
254 	}
255 	*busp = bus;
256 	*devp = dev;
257 
258 	return ret;
259 }
260 
261 int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
262 		       const char *drv_name, const char *dev_name,
263 		       struct udevice **busp, struct spi_slave **devp)
264 {
265 	struct udevice *bus, *dev;
266 	bool created = false;
267 	int ret;
268 
269 	ret = uclass_get_device_by_seq(UCLASS_SPI, busnum, &bus);
270 	if (ret) {
271 		printf("Invalid bus %d (err=%d)\n", busnum, ret);
272 		return ret;
273 	}
274 	ret = spi_find_chip_select(bus, cs, &dev);
275 
276 	/*
277 	 * If there is no such device, create one automatically. This means
278 	 * that we don't need a device tree node or platform data for the
279 	 * SPI flash chip - we will bind to the correct driver.
280 	 */
281 	if (ret == -ENODEV && drv_name) {
282 		struct dm_spi_slave_platdata *plat;
283 
284 		debug("%s: Binding new device '%s', busnum=%d, cs=%d, driver=%s\n",
285 		      __func__, dev_name, busnum, cs, drv_name);
286 		ret = device_bind_driver(bus, drv_name, dev_name, &dev);
287 		if (ret)
288 			return ret;
289 		plat = dev_get_parent_platdata(dev);
290 		plat->cs = cs;
291 		plat->max_hz = speed;
292 		plat->mode = mode;
293 		created = true;
294 	} else if (ret) {
295 		printf("Invalid chip select %d:%d (err=%d)\n", busnum, cs,
296 		       ret);
297 		return ret;
298 	}
299 
300 	if (!device_active(dev)) {
301 		struct spi_slave *slave;
302 
303 		ret = device_probe(dev);
304 		if (ret)
305 			goto err;
306 		slave = dev_get_parent_priv(dev);
307 		slave->dev = dev;
308 	}
309 
310 	ret = spi_set_speed_mode(bus, speed, mode);
311 	if (ret)
312 		goto err;
313 
314 	*busp = bus;
315 	*devp = dev_get_parent_priv(dev);
316 	debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp);
317 
318 	return 0;
319 
320 err:
321 	debug("%s: Error path, credted=%d, device '%s'\n", __func__,
322 	      created, dev->name);
323 	if (created) {
324 		device_remove(dev);
325 		device_unbind(dev);
326 	}
327 
328 	return ret;
329 }
330 
331 /* Compatibility function - to be removed */
332 struct spi_slave *spi_setup_slave_fdt(const void *blob, int node,
333 				      int bus_node)
334 {
335 	struct udevice *bus, *dev;
336 	int ret;
337 
338 	ret = uclass_get_device_by_of_offset(UCLASS_SPI, bus_node, &bus);
339 	if (ret)
340 		return NULL;
341 	ret = device_get_child_by_of_offset(bus, node, &dev);
342 	if (ret)
343 		return NULL;
344 	return dev_get_parent_priv(dev);
345 }
346 
347 /* Compatibility function - to be removed */
348 struct spi_slave *spi_setup_slave(unsigned int busnum, unsigned int cs,
349 				  unsigned int speed, unsigned int mode)
350 {
351 	struct spi_slave *slave;
352 	struct udevice *dev;
353 	int ret;
354 
355 	ret = spi_get_bus_and_cs(busnum, cs, speed, mode, NULL, 0, &dev,
356 				  &slave);
357 	if (ret)
358 		return NULL;
359 
360 	return slave;
361 }
362 
363 void spi_free_slave(struct spi_slave *slave)
364 {
365 	device_remove(slave->dev);
366 	slave->dev = NULL;
367 }
368 
369 int spi_slave_ofdata_to_platdata(const void *blob, int node,
370 				 struct dm_spi_slave_platdata *plat)
371 {
372 	int mode = 0, mode_rx = 0;
373 	int value;
374 
375 	plat->cs = fdtdec_get_int(blob, node, "reg", -1);
376 	plat->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency", 0);
377 	if (fdtdec_get_bool(blob, node, "spi-cpol"))
378 		mode |= SPI_CPOL;
379 	if (fdtdec_get_bool(blob, node, "spi-cpha"))
380 		mode |= SPI_CPHA;
381 	if (fdtdec_get_bool(blob, node, "spi-cs-high"))
382 		mode |= SPI_CS_HIGH;
383 	if (fdtdec_get_bool(blob, node, "spi-3wire"))
384 		mode |= SPI_3WIRE;
385 	if (fdtdec_get_bool(blob, node, "spi-half-duplex"))
386 		mode |= SPI_PREAMBLE;
387 
388 	/* Device DUAL/QUAD mode */
389 	value = fdtdec_get_uint(blob, node, "spi-tx-bus-width", 1);
390 	switch (value) {
391 	case 1:
392 		break;
393 	case 2:
394 		mode |= SPI_TX_DUAL;
395 		break;
396 	case 4:
397 		mode |= SPI_TX_QUAD;
398 		break;
399 	default:
400 		error("spi-tx-bus-width %d not supported\n", value);
401 		break;
402 	}
403 
404 	plat->mode = mode;
405 
406 	value = fdtdec_get_uint(blob, node, "spi-rx-bus-width", 1);
407 	switch (value) {
408 	case 1:
409 		break;
410 	case 2:
411 		mode_rx |= SPI_RX_DUAL;
412 		break;
413 	case 4:
414 		mode_rx |= SPI_RX_QUAD;
415 		break;
416 	default:
417 		error("spi-rx-bus-width %d not supported\n", value);
418 		break;
419 	}
420 
421 	plat->mode_rx = mode_rx;
422 
423 	return 0;
424 }
425 
426 UCLASS_DRIVER(spi) = {
427 	.id		= UCLASS_SPI,
428 	.name		= "spi",
429 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
430 	.post_bind	= spi_post_bind,
431 	.post_probe	= spi_post_probe,
432 	.child_pre_probe = spi_child_pre_probe,
433 	.per_device_auto_alloc_size = sizeof(struct dm_spi_bus),
434 	.per_child_auto_alloc_size = sizeof(struct spi_slave),
435 	.per_child_platdata_auto_alloc_size =
436 			sizeof(struct dm_spi_slave_platdata),
437 	.child_post_bind = spi_child_post_bind,
438 };
439 
440 UCLASS_DRIVER(spi_generic) = {
441 	.id		= UCLASS_SPI_GENERIC,
442 	.name		= "spi_generic",
443 };
444 
445 U_BOOT_DRIVER(spi_generic_drv) = {
446 	.name		= "spi_generic_drv",
447 	.id		= UCLASS_SPI_GENERIC,
448 };
449