dma-crossbar.c

  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
 18static const u32 ti_xbar_type[] = {
 19	[TI_XBAR_DRA7] = TI_XBAR_DRA7,
 20	[TI_XBAR_AM335X] = TI_XBAR_AM335X,
 21};
 22
 23static 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
 38struct 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
 47struct ti_am335x_xbar_map {
 48	u16 dma_line;
 49	u8 mux_val;
 50};
 51
 52static 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
 65static 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
 77static 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 = ERR_PTR(-EINVAL);
 83
 84	if (dma_spec->args_count != 3)
 85		goto out_put_pdev;
 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		goto out_put_pdev;
 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		goto out_put_pdev;
 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		goto out_put_pdev;
104	}
105
106	map = kzalloc(sizeof(*map), GFP_KERNEL);
107	if (!map) {
108		of_node_put(dma_spec->np);
109		map = ERR_PTR(-ENOMEM);
110		goto out_put_pdev;
111	}
112
113	map->dma_line = (u16)dma_spec->args[0];
114	map->mux_val = (u8)dma_spec->args[2];
115
116	dma_spec->args[2] = 0;
117	dma_spec->args_count = 2;
118
119	dev_dbg(&pdev->dev, "Mapping XBAR event%u to DMA%u\n",
120		map->mux_val, map->dma_line);
121
122	ti_am335x_xbar_write(xbar->iomem, map->dma_line, map->mux_val);
123
124out_put_pdev:
125	put_device(&pdev->dev);
126
127	return map;
128}
129
130static const struct of_device_id ti_am335x_master_match[] __maybe_unused = {
131	{ .compatible = "ti,edma3-tpcc", },
132	{},
133};
134
135static int ti_am335x_xbar_probe(struct platform_device *pdev)
136{
137	struct device_node *node = pdev->dev.of_node;
138	const struct of_device_id *match;
139	struct device_node *dma_node;
140	struct ti_am335x_xbar_data *xbar;
141	void __iomem *iomem;
142	int i, ret;
143
144	if (!node)
145		return -ENODEV;
146
147	xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
148	if (!xbar)
149		return -ENOMEM;
150
151	dma_node = of_parse_phandle(node, "dma-masters", 0);
152	if (!dma_node) {
153		dev_err(&pdev->dev, "Can't get DMA master node\n");
154		return -ENODEV;
155	}
156
157	match = of_match_node(ti_am335x_master_match, dma_node);
158	if (!match) {
159		dev_err(&pdev->dev, "DMA master is not supported\n");
160		of_node_put(dma_node);
161		return -EINVAL;
162	}
163
164	if (of_property_read_u32(dma_node, "dma-requests",
165				 &xbar->dma_requests)) {
166		dev_info(&pdev->dev,
167			 "Missing XBAR output information, using %u.\n",
168			 TI_AM335X_XBAR_LINES);
169		xbar->dma_requests = TI_AM335X_XBAR_LINES;
170	}
171	of_node_put(dma_node);
172
173	if (of_property_read_u32(node, "dma-requests", &xbar->xbar_events)) {
174		dev_info(&pdev->dev,
175			 "Missing XBAR input information, using %u.\n",
176			 TI_AM335X_XBAR_LINES);
177		xbar->xbar_events = TI_AM335X_XBAR_LINES;
178	}
179
180	iomem = devm_platform_ioremap_resource(pdev, 0);
181	if (IS_ERR(iomem))
182		return PTR_ERR(iomem);
183
184	xbar->iomem = iomem;
185
186	xbar->dmarouter.dev = &pdev->dev;
187	xbar->dmarouter.route_free = ti_am335x_xbar_free;
188
189	platform_set_drvdata(pdev, xbar);
190
191	/* Reset the crossbar */
192	for (i = 0; i < xbar->dma_requests; i++)
193		ti_am335x_xbar_write(xbar->iomem, i, 0);
194
195	ret = of_dma_router_register(node, ti_am335x_xbar_route_allocate,
196				     &xbar->dmarouter);
197
198	return ret;
199}
200
201/* Crossbar on DRA7xx family */
202#define TI_DRA7_XBAR_OUTPUTS	127
203#define TI_DRA7_XBAR_INPUTS	256
204
205struct ti_dra7_xbar_data {
206	void __iomem *iomem;
207
208	struct dma_router dmarouter;
209	struct mutex mutex;
210	unsigned long *dma_inuse;
211
212	u16 safe_val; /* Value to rest the crossbar lines */
213	u32 xbar_requests; /* number of DMA requests connected to XBAR */
214	u32 dma_requests; /* number of DMA requests forwarded to DMA */
215	u32 dma_offset;
216};
217
218struct ti_dra7_xbar_map {
219	u16 xbar_in;
220	int xbar_out;
221};
222
223static inline void ti_dra7_xbar_write(void __iomem *iomem, int xbar, u16 val)
224{
225	writew_relaxed(val, iomem + (xbar * 2));
226}
227
228static void ti_dra7_xbar_free(struct device *dev, void *route_data)
229{
230	struct ti_dra7_xbar_data *xbar = dev_get_drvdata(dev);
231	struct ti_dra7_xbar_map *map = route_data;
232
233	dev_dbg(dev, "Unmapping XBAR%u (was routed to %d)\n",
234		map->xbar_in, map->xbar_out);
235
236	ti_dra7_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val);
237	mutex_lock(&xbar->mutex);
238	clear_bit(map->xbar_out, xbar->dma_inuse);
239	mutex_unlock(&xbar->mutex);
240	kfree(map);
241}
242
243static void *ti_dra7_xbar_route_allocate(struct of_phandle_args *dma_spec,
244					 struct of_dma *ofdma)
245{
246	struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
247	struct ti_dra7_xbar_data *xbar = platform_get_drvdata(pdev);
248	struct ti_dra7_xbar_map *map = ERR_PTR(-EINVAL);
249
250	if (dma_spec->args[0] >= xbar->xbar_requests) {
251		dev_err(&pdev->dev, "Invalid XBAR request number: %d\n",
252			dma_spec->args[0]);
253		goto out_put_pdev;
254	}
255
256	/* The of_node_put() will be done in the core for the node */
257	dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
258	if (!dma_spec->np) {
259		dev_err(&pdev->dev, "Can't get DMA master\n");
260		goto out_put_pdev;
261	}
262
263	map = kzalloc(sizeof(*map), GFP_KERNEL);
264	if (!map) {
265		of_node_put(dma_spec->np);
266		map = ERR_PTR(-ENOMEM);
267		goto out_put_pdev;
268	}
269
270	mutex_lock(&xbar->mutex);
271	map->xbar_out = find_first_zero_bit(xbar->dma_inuse,
272					    xbar->dma_requests);
273	if (map->xbar_out == xbar->dma_requests) {
274		mutex_unlock(&xbar->mutex);
275		dev_err(&pdev->dev, "Run out of free DMA requests\n");
276		kfree(map);
277		of_node_put(dma_spec->np);
278		map = ERR_PTR(-ENOMEM);
279		goto out_put_pdev;
280	}
281	set_bit(map->xbar_out, xbar->dma_inuse);
282	mutex_unlock(&xbar->mutex);
283
284	map->xbar_in = (u16)dma_spec->args[0];
285
286	dma_spec->args[0] = map->xbar_out + xbar->dma_offset;
287
288	dev_dbg(&pdev->dev, "Mapping XBAR%u to DMA%d\n",
289		map->xbar_in, map->xbar_out);
290
291	ti_dra7_xbar_write(xbar->iomem, map->xbar_out, map->xbar_in);
292
293out_put_pdev:
294	put_device(&pdev->dev);
295
296	return map;
297}
298
299#define TI_XBAR_EDMA_OFFSET	0
300#define TI_XBAR_SDMA_OFFSET	1
301static const u32 ti_dma_offset[] = {
302	[TI_XBAR_EDMA_OFFSET] = 0,
303	[TI_XBAR_SDMA_OFFSET] = 1,
304};
305
306static const struct of_device_id ti_dra7_master_match[] __maybe_unused = {
307	{
308		.compatible = "ti,omap4430-sdma",
309		.data = &ti_dma_offset[TI_XBAR_SDMA_OFFSET],
310	},
311	{
312		.compatible = "ti,edma3",
313		.data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
314	},
315	{
316		.compatible = "ti,edma3-tpcc",
317		.data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
318	},
319	{},
320};
321
322static inline void ti_dra7_xbar_reserve(int offset, int len, unsigned long *p)
323{
324	for (; len > 0; len--)
325		set_bit(offset + (len - 1), p);
326}
327
328static int ti_dra7_xbar_probe(struct platform_device *pdev)
329{
330	struct device_node *node = pdev->dev.of_node;
331	const struct of_device_id *match;
332	struct device_node *dma_node;
333	struct ti_dra7_xbar_data *xbar;
334	struct property *prop;
335	u32 safe_val;
336	int sz;
337	void __iomem *iomem;
338	int i, ret;
339
340	if (!node)
341		return -ENODEV;
342
343	xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
344	if (!xbar)
345		return -ENOMEM;
346
347	dma_node = of_parse_phandle(node, "dma-masters", 0);
348	if (!dma_node) {
349		dev_err(&pdev->dev, "Can't get DMA master node\n");
350		return -ENODEV;
351	}
352
353	match = of_match_node(ti_dra7_master_match, dma_node);
354	if (!match) {
355		dev_err(&pdev->dev, "DMA master is not supported\n");
356		of_node_put(dma_node);
357		return -EINVAL;
358	}
359
360	if (of_property_read_u32(dma_node, "dma-requests",
361				 &xbar->dma_requests)) {
362		dev_info(&pdev->dev,
363			 "Missing XBAR output information, using %u.\n",
364			 TI_DRA7_XBAR_OUTPUTS);
365		xbar->dma_requests = TI_DRA7_XBAR_OUTPUTS;
366	}
367	of_node_put(dma_node);
368
369	xbar->dma_inuse = devm_kcalloc(&pdev->dev,
370				       BITS_TO_LONGS(xbar->dma_requests),
371				       sizeof(unsigned long), GFP_KERNEL);
372	if (!xbar->dma_inuse)
373		return -ENOMEM;
374
375	if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
376		dev_info(&pdev->dev,
377			 "Missing XBAR input information, using %u.\n",
378			 TI_DRA7_XBAR_INPUTS);
379		xbar->xbar_requests = TI_DRA7_XBAR_INPUTS;
380	}
381
382	if (!of_property_read_u32(node, "ti,dma-safe-map", &safe_val))
383		xbar->safe_val = (u16)safe_val;
384
385
386	prop = of_find_property(node, "ti,reserved-dma-request-ranges", &sz);
387	if (prop) {
388		const char pname[] = "ti,reserved-dma-request-ranges";
389		u32 (*rsv_events)[2];
390		size_t nelm = sz / sizeof(*rsv_events);
391		int i;
392
393		if (!nelm)
394			return -EINVAL;
395
396		rsv_events = kcalloc(nelm, sizeof(*rsv_events), GFP_KERNEL);
397		if (!rsv_events)
398			return -ENOMEM;
399
400		ret = of_property_read_u32_array(node, pname, (u32 *)rsv_events,
401						 nelm * 2);
402		if (ret) {
403			kfree(rsv_events);
404			return ret;
405		}
406
407		for (i = 0; i < nelm; i++) {
408			ti_dra7_xbar_reserve(rsv_events[i][0], rsv_events[i][1],
409					     xbar->dma_inuse);
410		}
411		kfree(rsv_events);
412	}
413
414	iomem = devm_platform_ioremap_resource(pdev, 0);
415	if (IS_ERR(iomem))
416		return PTR_ERR(iomem);
417
418	xbar->iomem = iomem;
419
420	xbar->dmarouter.dev = &pdev->dev;
421	xbar->dmarouter.route_free = ti_dra7_xbar_free;
422	xbar->dma_offset = *(u32 *)match->data;
423
424	mutex_init(&xbar->mutex);
425	platform_set_drvdata(pdev, xbar);
426
427	/* Reset the crossbar */
428	for (i = 0; i < xbar->dma_requests; i++) {
429		if (!test_bit(i, xbar->dma_inuse))
430			ti_dra7_xbar_write(xbar->iomem, i, xbar->safe_val);
431	}
432
433	ret = of_dma_router_register(node, ti_dra7_xbar_route_allocate,
434				     &xbar->dmarouter);
435	if (ret) {
436		/* Restore the defaults for the crossbar */
437		for (i = 0; i < xbar->dma_requests; i++) {
438			if (!test_bit(i, xbar->dma_inuse))
439				ti_dra7_xbar_write(xbar->iomem, i, i);
440		}
441	}
442
443	return ret;
444}
445
446static int ti_dma_xbar_probe(struct platform_device *pdev)
447{
448	const struct of_device_id *match;
449	int ret;
450
451	match = of_match_node(ti_dma_xbar_match, pdev->dev.of_node);
452	if (unlikely(!match))
453		return -EINVAL;
454
455	switch (*(u32 *)match->data) {
456	case TI_XBAR_DRA7:
457		ret = ti_dra7_xbar_probe(pdev);
458		break;
459	case TI_XBAR_AM335X:
460		ret = ti_am335x_xbar_probe(pdev);
461		break;
462	default:
463		dev_err(&pdev->dev, "Unsupported crossbar\n");
464		ret = -ENODEV;
465		break;
466	}
467
468	return ret;
469}
470
471static struct platform_driver ti_dma_xbar_driver = {
472	.driver = {
473		.name = "ti-dma-crossbar",
474		.of_match_table = ti_dma_xbar_match,
475	},
476	.probe	= ti_dma_xbar_probe,
477};
478
479static int omap_dmaxbar_init(void)
480{
481	return platform_driver_register(&ti_dma_xbar_driver);
482}
483arch_initcall(omap_dmaxbar_init);