xref: /openbmc/linux/drivers/dma/ti/dma-crossbar.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
4  *  Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
5  */
6 #include <linux/slab.h>
7 #include <linux/err.h>
8 #include <linux/init.h>
9 #include <linux/list.h>
10 #include <linux/io.h>
11 #include <linux/of_address.h>
12 #include <linux/of_device.h>
13 #include <linux/of_dma.h>
14 
15 #define TI_XBAR_DRA7		0
16 #define TI_XBAR_AM335X		1
17 static const u32 ti_xbar_type[] = {
18 	[TI_XBAR_DRA7] = TI_XBAR_DRA7,
19 	[TI_XBAR_AM335X] = TI_XBAR_AM335X,
20 };
21 
22 static const struct of_device_id ti_dma_xbar_match[] = {
23 	{
24 		.compatible = "ti,dra7-dma-crossbar",
25 		.data = &ti_xbar_type[TI_XBAR_DRA7],
26 	},
27 	{
28 		.compatible = "ti,am335x-edma-crossbar",
29 		.data = &ti_xbar_type[TI_XBAR_AM335X],
30 	},
31 	{},
32 };
33 
34 /* Crossbar on AM335x/AM437x family */
35 #define TI_AM335X_XBAR_LINES	64
36 
37 struct ti_am335x_xbar_data {
38 	void __iomem *iomem;
39 
40 	struct dma_router dmarouter;
41 
42 	u32 xbar_events; /* maximum number of events to select in xbar */
43 	u32 dma_requests; /* number of DMA requests on eDMA */
44 };
45 
46 struct ti_am335x_xbar_map {
47 	u16 dma_line;
48 	u8 mux_val;
49 };
50 
51 static inline void ti_am335x_xbar_write(void __iomem *iomem, int event, u8 val)
52 {
53 	/*
54 	 * TPCC_EVT_MUX_60_63 register layout is different than the
55 	 * rest, in the sense, that event 63 is mapped to lowest byte
56 	 * and event 60 is mapped to highest, handle it separately.
57 	 */
58 	if (event >= 60 && event <= 63)
59 		writeb_relaxed(val, iomem + (63 - event % 4));
60 	else
61 		writeb_relaxed(val, iomem + event);
62 }
63 
64 static void ti_am335x_xbar_free(struct device *dev, void *route_data)
65 {
66 	struct ti_am335x_xbar_data *xbar = dev_get_drvdata(dev);
67 	struct ti_am335x_xbar_map *map = route_data;
68 
69 	dev_dbg(dev, "Unmapping XBAR event %u on channel %u\n",
70 		map->mux_val, map->dma_line);
71 
72 	ti_am335x_xbar_write(xbar->iomem, map->dma_line, 0);
73 	kfree(map);
74 }
75 
76 static void *ti_am335x_xbar_route_allocate(struct of_phandle_args *dma_spec,
77 					   struct of_dma *ofdma)
78 {
79 	struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
80 	struct ti_am335x_xbar_data *xbar = platform_get_drvdata(pdev);
81 	struct ti_am335x_xbar_map *map;
82 
83 	if (dma_spec->args_count != 3)
84 		return ERR_PTR(-EINVAL);
85 
86 	if (dma_spec->args[2] >= xbar->xbar_events) {
87 		dev_err(&pdev->dev, "Invalid XBAR event number: %d\n",
88 			dma_spec->args[2]);
89 		return ERR_PTR(-EINVAL);
90 	}
91 
92 	if (dma_spec->args[0] >= xbar->dma_requests) {
93 		dev_err(&pdev->dev, "Invalid DMA request line number: %d\n",
94 			dma_spec->args[0]);
95 		return ERR_PTR(-EINVAL);
96 	}
97 
98 	/* The of_node_put() will be done in the core for the node */
99 	dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
100 	if (!dma_spec->np) {
101 		dev_err(&pdev->dev, "Can't get DMA master\n");
102 		return ERR_PTR(-EINVAL);
103 	}
104 
105 	map = kzalloc(sizeof(*map), GFP_KERNEL);
106 	if (!map) {
107 		of_node_put(dma_spec->np);
108 		return ERR_PTR(-ENOMEM);
109 	}
110 
111 	map->dma_line = (u16)dma_spec->args[0];
112 	map->mux_val = (u8)dma_spec->args[2];
113 
114 	dma_spec->args[2] = 0;
115 	dma_spec->args_count = 2;
116 
117 	dev_dbg(&pdev->dev, "Mapping XBAR event%u to DMA%u\n",
118 		map->mux_val, map->dma_line);
119 
120 	ti_am335x_xbar_write(xbar->iomem, map->dma_line, map->mux_val);
121 
122 	return map;
123 }
124 
125 static const struct of_device_id ti_am335x_master_match[] __maybe_unused = {
126 	{ .compatible = "ti,edma3-tpcc", },
127 	{},
128 };
129 
130 static int ti_am335x_xbar_probe(struct platform_device *pdev)
131 {
132 	struct device_node *node = pdev->dev.of_node;
133 	const struct of_device_id *match;
134 	struct device_node *dma_node;
135 	struct ti_am335x_xbar_data *xbar;
136 	void __iomem *iomem;
137 	int i, ret;
138 
139 	if (!node)
140 		return -ENODEV;
141 
142 	xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
143 	if (!xbar)
144 		return -ENOMEM;
145 
146 	dma_node = of_parse_phandle(node, "dma-masters", 0);
147 	if (!dma_node) {
148 		dev_err(&pdev->dev, "Can't get DMA master node\n");
149 		return -ENODEV;
150 	}
151 
152 	match = of_match_node(ti_am335x_master_match, dma_node);
153 	if (!match) {
154 		dev_err(&pdev->dev, "DMA master is not supported\n");
155 		of_node_put(dma_node);
156 		return -EINVAL;
157 	}
158 
159 	if (of_property_read_u32(dma_node, "dma-requests",
160 				 &xbar->dma_requests)) {
161 		dev_info(&pdev->dev,
162 			 "Missing XBAR output information, using %u.\n",
163 			 TI_AM335X_XBAR_LINES);
164 		xbar->dma_requests = TI_AM335X_XBAR_LINES;
165 	}
166 	of_node_put(dma_node);
167 
168 	if (of_property_read_u32(node, "dma-requests", &xbar->xbar_events)) {
169 		dev_info(&pdev->dev,
170 			 "Missing XBAR input information, using %u.\n",
171 			 TI_AM335X_XBAR_LINES);
172 		xbar->xbar_events = TI_AM335X_XBAR_LINES;
173 	}
174 
175 	iomem = devm_platform_ioremap_resource(pdev, 0);
176 	if (IS_ERR(iomem))
177 		return PTR_ERR(iomem);
178 
179 	xbar->iomem = iomem;
180 
181 	xbar->dmarouter.dev = &pdev->dev;
182 	xbar->dmarouter.route_free = ti_am335x_xbar_free;
183 
184 	platform_set_drvdata(pdev, xbar);
185 
186 	/* Reset the crossbar */
187 	for (i = 0; i < xbar->dma_requests; i++)
188 		ti_am335x_xbar_write(xbar->iomem, i, 0);
189 
190 	ret = of_dma_router_register(node, ti_am335x_xbar_route_allocate,
191 				     &xbar->dmarouter);
192 
193 	return ret;
194 }
195 
196 /* Crossbar on DRA7xx family */
197 #define TI_DRA7_XBAR_OUTPUTS	127
198 #define TI_DRA7_XBAR_INPUTS	256
199 
200 struct ti_dra7_xbar_data {
201 	void __iomem *iomem;
202 
203 	struct dma_router dmarouter;
204 	struct mutex mutex;
205 	unsigned long *dma_inuse;
206 
207 	u16 safe_val; /* Value to rest the crossbar lines */
208 	u32 xbar_requests; /* number of DMA requests connected to XBAR */
209 	u32 dma_requests; /* number of DMA requests forwarded to DMA */
210 	u32 dma_offset;
211 };
212 
213 struct ti_dra7_xbar_map {
214 	u16 xbar_in;
215 	int xbar_out;
216 };
217 
218 static inline void ti_dra7_xbar_write(void __iomem *iomem, int xbar, u16 val)
219 {
220 	writew_relaxed(val, iomem + (xbar * 2));
221 }
222 
223 static void ti_dra7_xbar_free(struct device *dev, void *route_data)
224 {
225 	struct ti_dra7_xbar_data *xbar = dev_get_drvdata(dev);
226 	struct ti_dra7_xbar_map *map = route_data;
227 
228 	dev_dbg(dev, "Unmapping XBAR%u (was routed to %d)\n",
229 		map->xbar_in, map->xbar_out);
230 
231 	ti_dra7_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val);
232 	mutex_lock(&xbar->mutex);
233 	clear_bit(map->xbar_out, xbar->dma_inuse);
234 	mutex_unlock(&xbar->mutex);
235 	kfree(map);
236 }
237 
238 static void *ti_dra7_xbar_route_allocate(struct of_phandle_args *dma_spec,
239 					 struct of_dma *ofdma)
240 {
241 	struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
242 	struct ti_dra7_xbar_data *xbar = platform_get_drvdata(pdev);
243 	struct ti_dra7_xbar_map *map;
244 
245 	if (dma_spec->args[0] >= xbar->xbar_requests) {
246 		dev_err(&pdev->dev, "Invalid XBAR request number: %d\n",
247 			dma_spec->args[0]);
248 		return ERR_PTR(-EINVAL);
249 	}
250 
251 	/* The of_node_put() will be done in the core for the node */
252 	dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
253 	if (!dma_spec->np) {
254 		dev_err(&pdev->dev, "Can't get DMA master\n");
255 		return ERR_PTR(-EINVAL);
256 	}
257 
258 	map = kzalloc(sizeof(*map), GFP_KERNEL);
259 	if (!map) {
260 		of_node_put(dma_spec->np);
261 		return ERR_PTR(-ENOMEM);
262 	}
263 
264 	mutex_lock(&xbar->mutex);
265 	map->xbar_out = find_first_zero_bit(xbar->dma_inuse,
266 					    xbar->dma_requests);
267 	if (map->xbar_out == xbar->dma_requests) {
268 		mutex_unlock(&xbar->mutex);
269 		dev_err(&pdev->dev, "Run out of free DMA requests\n");
270 		kfree(map);
271 		return ERR_PTR(-ENOMEM);
272 	}
273 	set_bit(map->xbar_out, xbar->dma_inuse);
274 	mutex_unlock(&xbar->mutex);
275 
276 	map->xbar_in = (u16)dma_spec->args[0];
277 
278 	dma_spec->args[0] = map->xbar_out + xbar->dma_offset;
279 
280 	dev_dbg(&pdev->dev, "Mapping XBAR%u to DMA%d\n",
281 		map->xbar_in, map->xbar_out);
282 
283 	ti_dra7_xbar_write(xbar->iomem, map->xbar_out, map->xbar_in);
284 
285 	return map;
286 }
287 
288 #define TI_XBAR_EDMA_OFFSET	0
289 #define TI_XBAR_SDMA_OFFSET	1
290 static const u32 ti_dma_offset[] = {
291 	[TI_XBAR_EDMA_OFFSET] = 0,
292 	[TI_XBAR_SDMA_OFFSET] = 1,
293 };
294 
295 static const struct of_device_id ti_dra7_master_match[] __maybe_unused = {
296 	{
297 		.compatible = "ti,omap4430-sdma",
298 		.data = &ti_dma_offset[TI_XBAR_SDMA_OFFSET],
299 	},
300 	{
301 		.compatible = "ti,edma3",
302 		.data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
303 	},
304 	{
305 		.compatible = "ti,edma3-tpcc",
306 		.data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
307 	},
308 	{},
309 };
310 
311 static inline void ti_dra7_xbar_reserve(int offset, int len, unsigned long *p)
312 {
313 	for (; len > 0; len--)
314 		set_bit(offset + (len - 1), p);
315 }
316 
317 static int ti_dra7_xbar_probe(struct platform_device *pdev)
318 {
319 	struct device_node *node = pdev->dev.of_node;
320 	const struct of_device_id *match;
321 	struct device_node *dma_node;
322 	struct ti_dra7_xbar_data *xbar;
323 	struct property *prop;
324 	u32 safe_val;
325 	int sz;
326 	void __iomem *iomem;
327 	int i, ret;
328 
329 	if (!node)
330 		return -ENODEV;
331 
332 	xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
333 	if (!xbar)
334 		return -ENOMEM;
335 
336 	dma_node = of_parse_phandle(node, "dma-masters", 0);
337 	if (!dma_node) {
338 		dev_err(&pdev->dev, "Can't get DMA master node\n");
339 		return -ENODEV;
340 	}
341 
342 	match = of_match_node(ti_dra7_master_match, dma_node);
343 	if (!match) {
344 		dev_err(&pdev->dev, "DMA master is not supported\n");
345 		of_node_put(dma_node);
346 		return -EINVAL;
347 	}
348 
349 	if (of_property_read_u32(dma_node, "dma-requests",
350 				 &xbar->dma_requests)) {
351 		dev_info(&pdev->dev,
352 			 "Missing XBAR output information, using %u.\n",
353 			 TI_DRA7_XBAR_OUTPUTS);
354 		xbar->dma_requests = TI_DRA7_XBAR_OUTPUTS;
355 	}
356 	of_node_put(dma_node);
357 
358 	xbar->dma_inuse = devm_kcalloc(&pdev->dev,
359 				       BITS_TO_LONGS(xbar->dma_requests),
360 				       sizeof(unsigned long), GFP_KERNEL);
361 	if (!xbar->dma_inuse)
362 		return -ENOMEM;
363 
364 	if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
365 		dev_info(&pdev->dev,
366 			 "Missing XBAR input information, using %u.\n",
367 			 TI_DRA7_XBAR_INPUTS);
368 		xbar->xbar_requests = TI_DRA7_XBAR_INPUTS;
369 	}
370 
371 	if (!of_property_read_u32(node, "ti,dma-safe-map", &safe_val))
372 		xbar->safe_val = (u16)safe_val;
373 
374 
375 	prop = of_find_property(node, "ti,reserved-dma-request-ranges", &sz);
376 	if (prop) {
377 		const char pname[] = "ti,reserved-dma-request-ranges";
378 		u32 (*rsv_events)[2];
379 		size_t nelm = sz / sizeof(*rsv_events);
380 		int i;
381 
382 		if (!nelm)
383 			return -EINVAL;
384 
385 		rsv_events = kcalloc(nelm, sizeof(*rsv_events), GFP_KERNEL);
386 		if (!rsv_events)
387 			return -ENOMEM;
388 
389 		ret = of_property_read_u32_array(node, pname, (u32 *)rsv_events,
390 						 nelm * 2);
391 		if (ret) {
392 			kfree(rsv_events);
393 			return ret;
394 		}
395 
396 		for (i = 0; i < nelm; i++) {
397 			ti_dra7_xbar_reserve(rsv_events[i][0], rsv_events[i][1],
398 					     xbar->dma_inuse);
399 		}
400 		kfree(rsv_events);
401 	}
402 
403 	iomem = devm_platform_ioremap_resource(pdev, 0);
404 	if (IS_ERR(iomem))
405 		return PTR_ERR(iomem);
406 
407 	xbar->iomem = iomem;
408 
409 	xbar->dmarouter.dev = &pdev->dev;
410 	xbar->dmarouter.route_free = ti_dra7_xbar_free;
411 	xbar->dma_offset = *(u32 *)match->data;
412 
413 	mutex_init(&xbar->mutex);
414 	platform_set_drvdata(pdev, xbar);
415 
416 	/* Reset the crossbar */
417 	for (i = 0; i < xbar->dma_requests; i++) {
418 		if (!test_bit(i, xbar->dma_inuse))
419 			ti_dra7_xbar_write(xbar->iomem, i, xbar->safe_val);
420 	}
421 
422 	ret = of_dma_router_register(node, ti_dra7_xbar_route_allocate,
423 				     &xbar->dmarouter);
424 	if (ret) {
425 		/* Restore the defaults for the crossbar */
426 		for (i = 0; i < xbar->dma_requests; i++) {
427 			if (!test_bit(i, xbar->dma_inuse))
428 				ti_dra7_xbar_write(xbar->iomem, i, i);
429 		}
430 	}
431 
432 	return ret;
433 }
434 
435 static int ti_dma_xbar_probe(struct platform_device *pdev)
436 {
437 	const struct of_device_id *match;
438 	int ret;
439 
440 	match = of_match_node(ti_dma_xbar_match, pdev->dev.of_node);
441 	if (unlikely(!match))
442 		return -EINVAL;
443 
444 	switch (*(u32 *)match->data) {
445 	case TI_XBAR_DRA7:
446 		ret = ti_dra7_xbar_probe(pdev);
447 		break;
448 	case TI_XBAR_AM335X:
449 		ret = ti_am335x_xbar_probe(pdev);
450 		break;
451 	default:
452 		dev_err(&pdev->dev, "Unsupported crossbar\n");
453 		ret = -ENODEV;
454 		break;
455 	}
456 
457 	return ret;
458 }
459 
460 static struct platform_driver ti_dma_xbar_driver = {
461 	.driver = {
462 		.name = "ti-dma-crossbar",
463 		.of_match_table = ti_dma_xbar_match,
464 	},
465 	.probe	= ti_dma_xbar_probe,
466 };
467 
468 static int omap_dmaxbar_init(void)
469 {
470 	return platform_driver_register(&ti_dma_xbar_driver);
471 }
472 arch_initcall(omap_dmaxbar_init);
473