xref: /openbmc/linux/drivers/dma/milbeaut-xdmac.c (revision e7bae9bb) 
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Copyright (C) 2019 Linaro Ltd.
4 // Copyright (C) 2019 Socionext Inc.
5 
6 #include <linux/bits.h>
7 #include <linux/dma-mapping.h>
8 #include <linux/dmaengine.h>
9 #include <linux/interrupt.h>
10 #include <linux/iopoll.h>
11 #include <linux/list.h>
12 #include <linux/module.h>
13 #include <linux/of_dma.h>
14 #include <linux/platform_device.h>
15 #include <linux/slab.h>
16 #include <linux/types.h>
17 #include <linux/bitfield.h>
18 
19 #include "virt-dma.h"
20 
21 /* global register */
22 #define M10V_XDACS 0x00
23 
24 /* channel local register */
25 #define M10V_XDTBC 0x10
26 #define M10V_XDSSA 0x14
27 #define M10V_XDDSA 0x18
28 #define M10V_XDSAC 0x1C
29 #define M10V_XDDAC 0x20
30 #define M10V_XDDCC 0x24
31 #define M10V_XDDES 0x28
32 #define M10V_XDDPC 0x2C
33 #define M10V_XDDSD 0x30
34 
35 #define M10V_XDACS_XE BIT(28)
36 
37 #define M10V_DEFBS	0x3
38 #define M10V_DEFBL	0xf
39 
40 #define M10V_XDSAC_SBS	GENMASK(17, 16)
41 #define M10V_XDSAC_SBL	GENMASK(11, 8)
42 
43 #define M10V_XDDAC_DBS	GENMASK(17, 16)
44 #define M10V_XDDAC_DBL	GENMASK(11, 8)
45 
46 #define M10V_XDDES_CE	BIT(28)
47 #define M10V_XDDES_SE	BIT(24)
48 #define M10V_XDDES_SA	BIT(15)
49 #define M10V_XDDES_TF	GENMASK(23, 20)
50 #define M10V_XDDES_EI	BIT(1)
51 #define M10V_XDDES_TI	BIT(0)
52 
53 #define M10V_XDDSD_IS_MASK	GENMASK(3, 0)
54 #define M10V_XDDSD_IS_NORMAL	0x8
55 
56 #define MLB_XDMAC_BUSWIDTHS	(BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
57 				 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
58 				 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
59 				 BIT(DMA_SLAVE_BUSWIDTH_8_BYTES))
60 
61 struct milbeaut_xdmac_desc {
62 	struct virt_dma_desc vd;
63 	size_t len;
64 	dma_addr_t src;
65 	dma_addr_t dst;
66 };
67 
68 struct milbeaut_xdmac_chan {
69 	struct virt_dma_chan vc;
70 	struct milbeaut_xdmac_desc *md;
71 	void __iomem *reg_ch_base;
72 };
73 
74 struct milbeaut_xdmac_device {
75 	struct dma_device ddev;
76 	void __iomem *reg_base;
77 	struct milbeaut_xdmac_chan channels[];
78 };
79 
80 static struct milbeaut_xdmac_chan *
81 to_milbeaut_xdmac_chan(struct virt_dma_chan *vc)
82 {
83 	return container_of(vc, struct milbeaut_xdmac_chan, vc);
84 }
85 
86 static struct milbeaut_xdmac_desc *
87 to_milbeaut_xdmac_desc(struct virt_dma_desc *vd)
88 {
89 	return container_of(vd, struct milbeaut_xdmac_desc, vd);
90 }
91 
92 /* mc->vc.lock must be held by caller */
93 static struct milbeaut_xdmac_desc *
94 milbeaut_xdmac_next_desc(struct milbeaut_xdmac_chan *mc)
95 {
96 	struct virt_dma_desc *vd;
97 
98 	vd = vchan_next_desc(&mc->vc);
99 	if (!vd) {
100 		mc->md = NULL;
101 		return NULL;
102 	}
103 
104 	list_del(&vd->node);
105 
106 	mc->md = to_milbeaut_xdmac_desc(vd);
107 
108 	return mc->md;
109 }
110 
111 /* mc->vc.lock must be held by caller */
112 static void milbeaut_chan_start(struct milbeaut_xdmac_chan *mc,
113 				struct milbeaut_xdmac_desc *md)
114 {
115 	u32 val;
116 
117 	/* Setup the channel */
118 	val = md->len - 1;
119 	writel_relaxed(val, mc->reg_ch_base + M10V_XDTBC);
120 
121 	val = md->src;
122 	writel_relaxed(val, mc->reg_ch_base + M10V_XDSSA);
123 
124 	val = md->dst;
125 	writel_relaxed(val, mc->reg_ch_base + M10V_XDDSA);
126 
127 	val = readl_relaxed(mc->reg_ch_base + M10V_XDSAC);
128 	val &= ~(M10V_XDSAC_SBS | M10V_XDSAC_SBL);
129 	val |= FIELD_PREP(M10V_XDSAC_SBS, M10V_DEFBS) |
130 		FIELD_PREP(M10V_XDSAC_SBL, M10V_DEFBL);
131 	writel_relaxed(val, mc->reg_ch_base + M10V_XDSAC);
132 
133 	val = readl_relaxed(mc->reg_ch_base + M10V_XDDAC);
134 	val &= ~(M10V_XDDAC_DBS | M10V_XDDAC_DBL);
135 	val |= FIELD_PREP(M10V_XDDAC_DBS, M10V_DEFBS) |
136 		FIELD_PREP(M10V_XDDAC_DBL, M10V_DEFBL);
137 	writel_relaxed(val, mc->reg_ch_base + M10V_XDDAC);
138 
139 	/* Start the channel */
140 	val = readl_relaxed(mc->reg_ch_base + M10V_XDDES);
141 	val &= ~(M10V_XDDES_CE | M10V_XDDES_SE | M10V_XDDES_TF |
142 		 M10V_XDDES_EI | M10V_XDDES_TI);
143 	val |= FIELD_PREP(M10V_XDDES_CE, 1) | FIELD_PREP(M10V_XDDES_SE, 1) |
144 		FIELD_PREP(M10V_XDDES_TF, 1) | FIELD_PREP(M10V_XDDES_EI, 1) |
145 		FIELD_PREP(M10V_XDDES_TI, 1);
146 	writel_relaxed(val, mc->reg_ch_base + M10V_XDDES);
147 }
148 
149 /* mc->vc.lock must be held by caller */
150 static void milbeaut_xdmac_start(struct milbeaut_xdmac_chan *mc)
151 {
152 	struct milbeaut_xdmac_desc *md;
153 
154 	md = milbeaut_xdmac_next_desc(mc);
155 	if (md)
156 		milbeaut_chan_start(mc, md);
157 }
158 
159 static irqreturn_t milbeaut_xdmac_interrupt(int irq, void *dev_id)
160 {
161 	struct milbeaut_xdmac_chan *mc = dev_id;
162 	struct milbeaut_xdmac_desc *md;
163 	unsigned long flags;
164 	u32 val;
165 
166 	spin_lock_irqsave(&mc->vc.lock, flags);
167 
168 	/* Ack and Stop */
169 	val = FIELD_PREP(M10V_XDDSD_IS_MASK, 0x0);
170 	writel_relaxed(val, mc->reg_ch_base + M10V_XDDSD);
171 
172 	md = mc->md;
173 	if (!md)
174 		goto out;
175 
176 	vchan_cookie_complete(&md->vd);
177 
178 	milbeaut_xdmac_start(mc);
179 out:
180 	spin_unlock_irqrestore(&mc->vc.lock, flags);
181 	return IRQ_HANDLED;
182 }
183 
184 static void milbeaut_xdmac_free_chan_resources(struct dma_chan *chan)
185 {
186 	vchan_free_chan_resources(to_virt_chan(chan));
187 }
188 
189 static struct dma_async_tx_descriptor *
190 milbeaut_xdmac_prep_memcpy(struct dma_chan *chan, dma_addr_t dst,
191 			   dma_addr_t src, size_t len, unsigned long flags)
192 {
193 	struct virt_dma_chan *vc = to_virt_chan(chan);
194 	struct milbeaut_xdmac_desc *md;
195 
196 	md = kzalloc(sizeof(*md), GFP_NOWAIT);
197 	if (!md)
198 		return NULL;
199 
200 	md->len = len;
201 	md->src = src;
202 	md->dst = dst;
203 
204 	return vchan_tx_prep(vc, &md->vd, flags);
205 }
206 
207 static int milbeaut_xdmac_terminate_all(struct dma_chan *chan)
208 {
209 	struct virt_dma_chan *vc = to_virt_chan(chan);
210 	struct milbeaut_xdmac_chan *mc = to_milbeaut_xdmac_chan(vc);
211 	unsigned long flags;
212 	u32 val;
213 
214 	LIST_HEAD(head);
215 
216 	spin_lock_irqsave(&vc->lock, flags);
217 
218 	/* Halt the channel */
219 	val = readl(mc->reg_ch_base + M10V_XDDES);
220 	val &= ~M10V_XDDES_CE;
221 	val |= FIELD_PREP(M10V_XDDES_CE, 0);
222 	writel(val, mc->reg_ch_base + M10V_XDDES);
223 
224 	if (mc->md) {
225 		vchan_terminate_vdesc(&mc->md->vd);
226 		mc->md = NULL;
227 	}
228 
229 	vchan_get_all_descriptors(vc, &head);
230 
231 	spin_unlock_irqrestore(&vc->lock, flags);
232 
233 	vchan_dma_desc_free_list(vc, &head);
234 
235 	return 0;
236 }
237 
238 static void milbeaut_xdmac_synchronize(struct dma_chan *chan)
239 {
240 	vchan_synchronize(to_virt_chan(chan));
241 }
242 
243 static void milbeaut_xdmac_issue_pending(struct dma_chan *chan)
244 {
245 	struct virt_dma_chan *vc = to_virt_chan(chan);
246 	struct milbeaut_xdmac_chan *mc = to_milbeaut_xdmac_chan(vc);
247 	unsigned long flags;
248 
249 	spin_lock_irqsave(&vc->lock, flags);
250 
251 	if (vchan_issue_pending(vc) && !mc->md)
252 		milbeaut_xdmac_start(mc);
253 
254 	spin_unlock_irqrestore(&vc->lock, flags);
255 }
256 
257 static void milbeaut_xdmac_desc_free(struct virt_dma_desc *vd)
258 {
259 	kfree(to_milbeaut_xdmac_desc(vd));
260 }
261 
262 static int milbeaut_xdmac_chan_init(struct platform_device *pdev,
263 				    struct milbeaut_xdmac_device *mdev,
264 				    int chan_id)
265 {
266 	struct device *dev = &pdev->dev;
267 	struct milbeaut_xdmac_chan *mc = &mdev->channels[chan_id];
268 	char *irq_name;
269 	int irq, ret;
270 
271 	irq = platform_get_irq(pdev, chan_id);
272 	if (irq < 0)
273 		return irq;
274 
275 	irq_name = devm_kasprintf(dev, GFP_KERNEL, "milbeaut-xdmac-%d",
276 				  chan_id);
277 	if (!irq_name)
278 		return -ENOMEM;
279 
280 	ret = devm_request_irq(dev, irq, milbeaut_xdmac_interrupt,
281 			       IRQF_SHARED, irq_name, mc);
282 	if (ret)
283 		return ret;
284 
285 	mc->reg_ch_base = mdev->reg_base + chan_id * 0x30;
286 
287 	mc->vc.desc_free = milbeaut_xdmac_desc_free;
288 	vchan_init(&mc->vc, &mdev->ddev);
289 
290 	return 0;
291 }
292 
293 static void enable_xdmac(struct milbeaut_xdmac_device *mdev)
294 {
295 	unsigned int val;
296 
297 	val = readl(mdev->reg_base + M10V_XDACS);
298 	val |= M10V_XDACS_XE;
299 	writel(val, mdev->reg_base + M10V_XDACS);
300 }
301 
302 static void disable_xdmac(struct milbeaut_xdmac_device *mdev)
303 {
304 	unsigned int val;
305 
306 	val = readl(mdev->reg_base + M10V_XDACS);
307 	val &= ~M10V_XDACS_XE;
308 	writel(val, mdev->reg_base + M10V_XDACS);
309 }
310 
311 static int milbeaut_xdmac_probe(struct platform_device *pdev)
312 {
313 	struct device *dev = &pdev->dev;
314 	struct milbeaut_xdmac_device *mdev;
315 	struct dma_device *ddev;
316 	int nr_chans, ret, i;
317 
318 	nr_chans = platform_irq_count(pdev);
319 	if (nr_chans < 0)
320 		return nr_chans;
321 
322 	mdev = devm_kzalloc(dev, struct_size(mdev, channels, nr_chans),
323 			    GFP_KERNEL);
324 	if (!mdev)
325 		return -ENOMEM;
326 
327 	mdev->reg_base = devm_platform_ioremap_resource(pdev, 0);
328 	if (IS_ERR(mdev->reg_base))
329 		return PTR_ERR(mdev->reg_base);
330 
331 	ddev = &mdev->ddev;
332 	ddev->dev = dev;
333 	dma_cap_set(DMA_MEMCPY, ddev->cap_mask);
334 	ddev->src_addr_widths = MLB_XDMAC_BUSWIDTHS;
335 	ddev->dst_addr_widths = MLB_XDMAC_BUSWIDTHS;
336 	ddev->device_free_chan_resources = milbeaut_xdmac_free_chan_resources;
337 	ddev->device_prep_dma_memcpy = milbeaut_xdmac_prep_memcpy;
338 	ddev->device_terminate_all = milbeaut_xdmac_terminate_all;
339 	ddev->device_synchronize = milbeaut_xdmac_synchronize;
340 	ddev->device_tx_status = dma_cookie_status;
341 	ddev->device_issue_pending = milbeaut_xdmac_issue_pending;
342 	INIT_LIST_HEAD(&ddev->channels);
343 
344 	for (i = 0; i < nr_chans; i++) {
345 		ret = milbeaut_xdmac_chan_init(pdev, mdev, i);
346 		if (ret)
347 			return ret;
348 	}
349 
350 	enable_xdmac(mdev);
351 
352 	ret = dma_async_device_register(ddev);
353 	if (ret)
354 		return ret;
355 
356 	ret = of_dma_controller_register(dev->of_node,
357 					 of_dma_simple_xlate, mdev);
358 	if (ret)
359 		goto unregister_dmac;
360 
361 	platform_set_drvdata(pdev, mdev);
362 
363 	return 0;
364 
365 unregister_dmac:
366 	dma_async_device_unregister(ddev);
367 	return ret;
368 }
369 
370 static int milbeaut_xdmac_remove(struct platform_device *pdev)
371 {
372 	struct milbeaut_xdmac_device *mdev = platform_get_drvdata(pdev);
373 	struct dma_chan *chan;
374 	int ret;
375 
376 	/*
377 	 * Before reaching here, almost all descriptors have been freed by the
378 	 * ->device_free_chan_resources() hook. However, each channel might
379 	 * be still holding one descriptor that was on-flight at that moment.
380 	 * Terminate it to make sure this hardware is no longer running. Then,
381 	 * free the channel resources once again to avoid memory leak.
382 	 */
383 	list_for_each_entry(chan, &mdev->ddev.channels, device_node) {
384 		ret = dmaengine_terminate_sync(chan);
385 		if (ret)
386 			return ret;
387 		milbeaut_xdmac_free_chan_resources(chan);
388 	}
389 
390 	of_dma_controller_free(pdev->dev.of_node);
391 	dma_async_device_unregister(&mdev->ddev);
392 
393 	disable_xdmac(mdev);
394 
395 	return 0;
396 }
397 
398 static const struct of_device_id milbeaut_xdmac_match[] = {
399 	{ .compatible = "socionext,milbeaut-m10v-xdmac" },
400 	{ /* sentinel */ }
401 };
402 MODULE_DEVICE_TABLE(of, milbeaut_xdmac_match);
403 
404 static struct platform_driver milbeaut_xdmac_driver = {
405 	.probe = milbeaut_xdmac_probe,
406 	.remove = milbeaut_xdmac_remove,
407 	.driver = {
408 		.name = "milbeaut-m10v-xdmac",
409 		.of_match_table = milbeaut_xdmac_match,
410 	},
411 };
412 module_platform_driver(milbeaut_xdmac_driver);
413 
414 MODULE_DESCRIPTION("Milbeaut XDMAC DmaEngine driver");
415 MODULE_LICENSE("GPL v2");
416