xref: /openbmc/linux/drivers/dma/ti/dma-crossbar.c (revision 897500c7)
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/platform_device.h>
7 #include <linux/slab.h>
8 #include <linux/err.h>
9 #include <linux/init.h>
10 #include <linux/list.h>
11 #include <linux/io.h>
12 #include <linux/of.h>
13 #include <linux/of_dma.h>
14 #include <linux/of_platform.h>
15 
16 #define TI_XBAR_DRA7		0
17 #define TI_XBAR_AM335X		1
18 static const u32 ti_xbar_type[] = {
19 	[TI_XBAR_DRA7] = TI_XBAR_DRA7,
20 	[TI_XBAR_AM335X] = TI_XBAR_AM335X,
21 };
22 
23 static const struct of_device_id ti_dma_xbar_match[] = {
24 	{
25 		.compatible = "ti,dra7-dma-crossbar",
26 		.data = &ti_xbar_type[TI_XBAR_DRA7],
27 	},
28 	{
29 		.compatible = "ti,am335x-edma-crossbar",
30 		.data = &ti_xbar_type[TI_XBAR_AM335X],
31 	},
32 	{},
33 };
34 
35 /* Crossbar on AM335x/AM437x family */
36 #define TI_AM335X_XBAR_LINES	64
37 
38 struct ti_am335x_xbar_data {
39 	void __iomem *iomem;
40 
41 	struct dma_router dmarouter;
42 
43 	u32 xbar_events; /* maximum number of events to select in xbar */
44 	u32 dma_requests; /* number of DMA requests on eDMA */
45 };
46 
47 struct ti_am335x_xbar_map {
48 	u16 dma_line;
49 	u8 mux_val;
50 };
51 
ti_am335x_xbar_write(void __iomem * iomem,int event,u8 val)52 static inline void ti_am335x_xbar_write(void __iomem *iomem, int event, u8 val)
53 {
54 	/*
55 	 * TPCC_EVT_MUX_60_63 register layout is different than the
56 	 * rest, in the sense, that event 63 is mapped to lowest byte
57 	 * and event 60 is mapped to highest, handle it separately.
58 	 */
59 	if (event >= 60 && event <= 63)
60 		writeb_relaxed(val, iomem + (63 - event % 4));
61 	else
62 		writeb_relaxed(val, iomem + event);
63 }
64 
ti_am335x_xbar_free(struct device * dev,void * route_data)65 static void ti_am335x_xbar_free(struct device *dev, void *route_data)
66 {
67 	struct ti_am335x_xbar_data *xbar = dev_get_drvdata(dev);
68 	struct ti_am335x_xbar_map *map = route_data;
69 
70 	dev_dbg(dev, "Unmapping XBAR event %u on channel %u\n",
71 		map->mux_val, map->dma_line);
72 
73 	ti_am335x_xbar_write(xbar->iomem, map->dma_line, 0);
74 	kfree(map);
75 }
76 
ti_am335x_xbar_route_allocate(struct of_phandle_args * dma_spec,struct of_dma * ofdma)77 static void *ti_am335x_xbar_route_allocate(struct of_phandle_args *dma_spec,
78 					   struct of_dma *ofdma)
79 {
80 	struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
81 	struct ti_am335x_xbar_data *xbar = platform_get_drvdata(pdev);
82 	struct ti_am335x_xbar_map *map;
83 
84 	if (dma_spec->args_count != 3)
85 		return ERR_PTR(-EINVAL);
86 
87 	if (dma_spec->args[2] >= xbar->xbar_events) {
88 		dev_err(&pdev->dev, "Invalid XBAR event number: %d\n",
89 			dma_spec->args[2]);
90 		return ERR_PTR(-EINVAL);
91 	}
92 
93 	if (dma_spec->args[0] >= xbar->dma_requests) {
94 		dev_err(&pdev->dev, "Invalid DMA request line number: %d\n",
95 			dma_spec->args[0]);
96 		return ERR_PTR(-EINVAL);
97 	}
98 
99 	/* The of_node_put() will be done in the core for the node */
100 	dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
101 	if (!dma_spec->np) {
102 		dev_err(&pdev->dev, "Can't get DMA master\n");
103 		return ERR_PTR(-EINVAL);
104 	}
105 
106 	map = kzalloc(sizeof(*map), GFP_KERNEL);
107 	if (!map) {
108 		of_node_put(dma_spec->np);
109 		return ERR_PTR(-ENOMEM);
110 	}
111 
112 	map->dma_line = (u16)dma_spec->args[0];
113 	map->mux_val = (u8)dma_spec->args[2];
114 
115 	dma_spec->args[2] = 0;
116 	dma_spec->args_count = 2;
117 
118 	dev_dbg(&pdev->dev, "Mapping XBAR event%u to DMA%u\n",
119 		map->mux_val, map->dma_line);
120 
121 	ti_am335x_xbar_write(xbar->iomem, map->dma_line, map->mux_val);
122 
123 	return map;
124 }
125 
126 static const struct of_device_id ti_am335x_master_match[] __maybe_unused = {
127 	{ .compatible = "ti,edma3-tpcc", },
128 	{},
129 };
130 
ti_am335x_xbar_probe(struct platform_device * pdev)131 static int ti_am335x_xbar_probe(struct platform_device *pdev)
132 {
133 	struct device_node *node = pdev->dev.of_node;
134 	const struct of_device_id *match;
135 	struct device_node *dma_node;
136 	struct ti_am335x_xbar_data *xbar;
137 	void __iomem *iomem;
138 	int i, ret;
139 
140 	if (!node)
141 		return -ENODEV;
142 
143 	xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
144 	if (!xbar)
145 		return -ENOMEM;
146 
147 	dma_node = of_parse_phandle(node, "dma-masters", 0);
148 	if (!dma_node) {
149 		dev_err(&pdev->dev, "Can't get DMA master node\n");
150 		return -ENODEV;
151 	}
152 
153 	match = of_match_node(ti_am335x_master_match, dma_node);
154 	if (!match) {
155 		dev_err(&pdev->dev, "DMA master is not supported\n");
156 		of_node_put(dma_node);
157 		return -EINVAL;
158 	}
159 
160 	if (of_property_read_u32(dma_node, "dma-requests",
161 				 &xbar->dma_requests)) {
162 		dev_info(&pdev->dev,
163 			 "Missing XBAR output information, using %u.\n",
164 			 TI_AM335X_XBAR_LINES);
165 		xbar->dma_requests = TI_AM335X_XBAR_LINES;
166 	}
167 	of_node_put(dma_node);
168 
169 	if (of_property_read_u32(node, "dma-requests", &xbar->xbar_events)) {
170 		dev_info(&pdev->dev,
171 			 "Missing XBAR input information, using %u.\n",
172 			 TI_AM335X_XBAR_LINES);
173 		xbar->xbar_events = TI_AM335X_XBAR_LINES;
174 	}
175 
176 	iomem = devm_platform_ioremap_resource(pdev, 0);
177 	if (IS_ERR(iomem))
178 		return PTR_ERR(iomem);
179 
180 	xbar->iomem = iomem;
181 
182 	xbar->dmarouter.dev = &pdev->dev;
183 	xbar->dmarouter.route_free = ti_am335x_xbar_free;
184 
185 	platform_set_drvdata(pdev, xbar);
186 
187 	/* Reset the crossbar */
188 	for (i = 0; i < xbar->dma_requests; i++)
189 		ti_am335x_xbar_write(xbar->iomem, i, 0);
190 
191 	ret = of_dma_router_register(node, ti_am335x_xbar_route_allocate,
192 				     &xbar->dmarouter);
193 
194 	return ret;
195 }
196 
197 /* Crossbar on DRA7xx family */
198 #define TI_DRA7_XBAR_OUTPUTS	127
199 #define TI_DRA7_XBAR_INPUTS	256
200 
201 struct ti_dra7_xbar_data {
202 	void __iomem *iomem;
203 
204 	struct dma_router dmarouter;
205 	struct mutex mutex;
206 	unsigned long *dma_inuse;
207 
208 	u16 safe_val; /* Value to rest the crossbar lines */
209 	u32 xbar_requests; /* number of DMA requests connected to XBAR */
210 	u32 dma_requests; /* number of DMA requests forwarded to DMA */
211 	u32 dma_offset;
212 };
213 
214 struct ti_dra7_xbar_map {
215 	u16 xbar_in;
216 	int xbar_out;
217 };
218 
ti_dra7_xbar_write(void __iomem * iomem,int xbar,u16 val)219 static inline void ti_dra7_xbar_write(void __iomem *iomem, int xbar, u16 val)
220 {
221 	writew_relaxed(val, iomem + (xbar * 2));
222 }
223 
ti_dra7_xbar_free(struct device * dev,void * route_data)224 static void ti_dra7_xbar_free(struct device *dev, void *route_data)
225 {
226 	struct ti_dra7_xbar_data *xbar = dev_get_drvdata(dev);
227 	struct ti_dra7_xbar_map *map = route_data;
228 
229 	dev_dbg(dev, "Unmapping XBAR%u (was routed to %d)\n",
230 		map->xbar_in, map->xbar_out);
231 
232 	ti_dra7_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val);
233 	mutex_lock(&xbar->mutex);
234 	clear_bit(map->xbar_out, xbar->dma_inuse);
235 	mutex_unlock(&xbar->mutex);
236 	kfree(map);
237 }
238 
ti_dra7_xbar_route_allocate(struct of_phandle_args * dma_spec,struct of_dma * ofdma)239 static void *ti_dra7_xbar_route_allocate(struct of_phandle_args *dma_spec,
240 					 struct of_dma *ofdma)
241 {
242 	struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
243 	struct ti_dra7_xbar_data *xbar = platform_get_drvdata(pdev);
244 	struct ti_dra7_xbar_map *map;
245 
246 	if (dma_spec->args[0] >= xbar->xbar_requests) {
247 		dev_err(&pdev->dev, "Invalid XBAR request number: %d\n",
248 			dma_spec->args[0]);
249 		put_device(&pdev->dev);
250 		return ERR_PTR(-EINVAL);
251 	}
252 
253 	/* The of_node_put() will be done in the core for the node */
254 	dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
255 	if (!dma_spec->np) {
256 		dev_err(&pdev->dev, "Can't get DMA master\n");
257 		put_device(&pdev->dev);
258 		return ERR_PTR(-EINVAL);
259 	}
260 
261 	map = kzalloc(sizeof(*map), GFP_KERNEL);
262 	if (!map) {
263 		of_node_put(dma_spec->np);
264 		put_device(&pdev->dev);
265 		return ERR_PTR(-ENOMEM);
266 	}
267 
268 	mutex_lock(&xbar->mutex);
269 	map->xbar_out = find_first_zero_bit(xbar->dma_inuse,
270 					    xbar->dma_requests);
271 	if (map->xbar_out == xbar->dma_requests) {
272 		mutex_unlock(&xbar->mutex);
273 		dev_err(&pdev->dev, "Run out of free DMA requests\n");
274 		kfree(map);
275 		of_node_put(dma_spec->np);
276 		put_device(&pdev->dev);
277 		return ERR_PTR(-ENOMEM);
278 	}
279 	set_bit(map->xbar_out, xbar->dma_inuse);
280 	mutex_unlock(&xbar->mutex);
281 
282 	map->xbar_in = (u16)dma_spec->args[0];
283 
284 	dma_spec->args[0] = map->xbar_out + xbar->dma_offset;
285 
286 	dev_dbg(&pdev->dev, "Mapping XBAR%u to DMA%d\n",
287 		map->xbar_in, map->xbar_out);
288 
289 	ti_dra7_xbar_write(xbar->iomem, map->xbar_out, map->xbar_in);
290 
291 	return map;
292 }
293 
294 #define TI_XBAR_EDMA_OFFSET	0
295 #define TI_XBAR_SDMA_OFFSET	1
296 static const u32 ti_dma_offset[] = {
297 	[TI_XBAR_EDMA_OFFSET] = 0,
298 	[TI_XBAR_SDMA_OFFSET] = 1,
299 };
300 
301 static const struct of_device_id ti_dra7_master_match[] __maybe_unused = {
302 	{
303 		.compatible = "ti,omap4430-sdma",
304 		.data = &ti_dma_offset[TI_XBAR_SDMA_OFFSET],
305 	},
306 	{
307 		.compatible = "ti,edma3",
308 		.data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
309 	},
310 	{
311 		.compatible = "ti,edma3-tpcc",
312 		.data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
313 	},
314 	{},
315 };
316 
ti_dra7_xbar_reserve(int offset,int len,unsigned long * p)317 static inline void ti_dra7_xbar_reserve(int offset, int len, unsigned long *p)
318 {
319 	for (; len > 0; len--)
320 		set_bit(offset + (len - 1), p);
321 }
322 
ti_dra7_xbar_probe(struct platform_device * pdev)323 static int ti_dra7_xbar_probe(struct platform_device *pdev)
324 {
325 	struct device_node *node = pdev->dev.of_node;
326 	const struct of_device_id *match;
327 	struct device_node *dma_node;
328 	struct ti_dra7_xbar_data *xbar;
329 	struct property *prop;
330 	u32 safe_val;
331 	int sz;
332 	void __iomem *iomem;
333 	int i, ret;
334 
335 	if (!node)
336 		return -ENODEV;
337 
338 	xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
339 	if (!xbar)
340 		return -ENOMEM;
341 
342 	dma_node = of_parse_phandle(node, "dma-masters", 0);
343 	if (!dma_node) {
344 		dev_err(&pdev->dev, "Can't get DMA master node\n");
345 		return -ENODEV;
346 	}
347 
348 	match = of_match_node(ti_dra7_master_match, dma_node);
349 	if (!match) {
350 		dev_err(&pdev->dev, "DMA master is not supported\n");
351 		of_node_put(dma_node);
352 		return -EINVAL;
353 	}
354 
355 	if (of_property_read_u32(dma_node, "dma-requests",
356 				 &xbar->dma_requests)) {
357 		dev_info(&pdev->dev,
358 			 "Missing XBAR output information, using %u.\n",
359 			 TI_DRA7_XBAR_OUTPUTS);
360 		xbar->dma_requests = TI_DRA7_XBAR_OUTPUTS;
361 	}
362 	of_node_put(dma_node);
363 
364 	xbar->dma_inuse = devm_kcalloc(&pdev->dev,
365 				       BITS_TO_LONGS(xbar->dma_requests),
366 				       sizeof(unsigned long), GFP_KERNEL);
367 	if (!xbar->dma_inuse)
368 		return -ENOMEM;
369 
370 	if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
371 		dev_info(&pdev->dev,
372 			 "Missing XBAR input information, using %u.\n",
373 			 TI_DRA7_XBAR_INPUTS);
374 		xbar->xbar_requests = TI_DRA7_XBAR_INPUTS;
375 	}
376 
377 	if (!of_property_read_u32(node, "ti,dma-safe-map", &safe_val))
378 		xbar->safe_val = (u16)safe_val;
379 
380 
381 	prop = of_find_property(node, "ti,reserved-dma-request-ranges", &sz);
382 	if (prop) {
383 		const char pname[] = "ti,reserved-dma-request-ranges";
384 		u32 (*rsv_events)[2];
385 		size_t nelm = sz / sizeof(*rsv_events);
386 		int i;
387 
388 		if (!nelm)
389 			return -EINVAL;
390 
391 		rsv_events = kcalloc(nelm, sizeof(*rsv_events), GFP_KERNEL);
392 		if (!rsv_events)
393 			return -ENOMEM;
394 
395 		ret = of_property_read_u32_array(node, pname, (u32 *)rsv_events,
396 						 nelm * 2);
397 		if (ret) {
398 			kfree(rsv_events);
399 			return ret;
400 		}
401 
402 		for (i = 0; i < nelm; i++) {
403 			ti_dra7_xbar_reserve(rsv_events[i][0], rsv_events[i][1],
404 					     xbar->dma_inuse);
405 		}
406 		kfree(rsv_events);
407 	}
408 
409 	iomem = devm_platform_ioremap_resource(pdev, 0);
410 	if (IS_ERR(iomem))
411 		return PTR_ERR(iomem);
412 
413 	xbar->iomem = iomem;
414 
415 	xbar->dmarouter.dev = &pdev->dev;
416 	xbar->dmarouter.route_free = ti_dra7_xbar_free;
417 	xbar->dma_offset = *(u32 *)match->data;
418 
419 	mutex_init(&xbar->mutex);
420 	platform_set_drvdata(pdev, xbar);
421 
422 	/* Reset the crossbar */
423 	for (i = 0; i < xbar->dma_requests; i++) {
424 		if (!test_bit(i, xbar->dma_inuse))
425 			ti_dra7_xbar_write(xbar->iomem, i, xbar->safe_val);
426 	}
427 
428 	ret = of_dma_router_register(node, ti_dra7_xbar_route_allocate,
429 				     &xbar->dmarouter);
430 	if (ret) {
431 		/* Restore the defaults for the crossbar */
432 		for (i = 0; i < xbar->dma_requests; i++) {
433 			if (!test_bit(i, xbar->dma_inuse))
434 				ti_dra7_xbar_write(xbar->iomem, i, i);
435 		}
436 	}
437 
438 	return ret;
439 }
440 
ti_dma_xbar_probe(struct platform_device * pdev)441 static int ti_dma_xbar_probe(struct platform_device *pdev)
442 {
443 	const struct of_device_id *match;
444 	int ret;
445 
446 	match = of_match_node(ti_dma_xbar_match, pdev->dev.of_node);
447 	if (unlikely(!match))
448 		return -EINVAL;
449 
450 	switch (*(u32 *)match->data) {
451 	case TI_XBAR_DRA7:
452 		ret = ti_dra7_xbar_probe(pdev);
453 		break;
454 	case TI_XBAR_AM335X:
455 		ret = ti_am335x_xbar_probe(pdev);
456 		break;
457 	default:
458 		dev_err(&pdev->dev, "Unsupported crossbar\n");
459 		ret = -ENODEV;
460 		break;
461 	}
462 
463 	return ret;
464 }
465 
466 static struct platform_driver ti_dma_xbar_driver = {
467 	.driver = {
468 		.name = "ti-dma-crossbar",
469 		.of_match_table = ti_dma_xbar_match,
470 	},
471 	.probe	= ti_dma_xbar_probe,
472 };
473 
omap_dmaxbar_init(void)474 static int omap_dmaxbar_init(void)
475 {
476 	return platform_driver_register(&ti_dma_xbar_driver);
477 }
478 arch_initcall(omap_dmaxbar_init);
479