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 *
to_milbeaut_xdmac_chan(struct virt_dma_chan * vc)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 *
to_milbeaut_xdmac_desc(struct virt_dma_desc * vd)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 *
milbeaut_xdmac_next_desc(struct milbeaut_xdmac_chan * mc)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 */
milbeaut_chan_start(struct milbeaut_xdmac_chan * mc,struct milbeaut_xdmac_desc * md)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 */
milbeaut_xdmac_start(struct milbeaut_xdmac_chan * mc)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
milbeaut_xdmac_interrupt(int irq,void * dev_id)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 u32 val;
164
165 spin_lock(&mc->vc.lock);
166
167 /* Ack and Stop */
168 val = FIELD_PREP(M10V_XDDSD_IS_MASK, 0x0);
169 writel_relaxed(val, mc->reg_ch_base + M10V_XDDSD);
170
171 md = mc->md;
172 if (!md)
173 goto out;
174
175 vchan_cookie_complete(&md->vd);
176
177 milbeaut_xdmac_start(mc);
178 out:
179 spin_unlock(&mc->vc.lock);
180 return IRQ_HANDLED;
181 }
182
milbeaut_xdmac_free_chan_resources(struct dma_chan * chan)183 static void milbeaut_xdmac_free_chan_resources(struct dma_chan *chan)
184 {
185 vchan_free_chan_resources(to_virt_chan(chan));
186 }
187
188 static struct dma_async_tx_descriptor *
milbeaut_xdmac_prep_memcpy(struct dma_chan * chan,dma_addr_t dst,dma_addr_t src,size_t len,unsigned long flags)189 milbeaut_xdmac_prep_memcpy(struct dma_chan *chan, dma_addr_t dst,
190 dma_addr_t src, size_t len, unsigned long flags)
191 {
192 struct virt_dma_chan *vc = to_virt_chan(chan);
193 struct milbeaut_xdmac_desc *md;
194
195 md = kzalloc(sizeof(*md), GFP_NOWAIT);
196 if (!md)
197 return NULL;
198
199 md->len = len;
200 md->src = src;
201 md->dst = dst;
202
203 return vchan_tx_prep(vc, &md->vd, flags);
204 }
205
milbeaut_xdmac_terminate_all(struct dma_chan * chan)206 static int milbeaut_xdmac_terminate_all(struct dma_chan *chan)
207 {
208 struct virt_dma_chan *vc = to_virt_chan(chan);
209 struct milbeaut_xdmac_chan *mc = to_milbeaut_xdmac_chan(vc);
210 unsigned long flags;
211 u32 val;
212
213 LIST_HEAD(head);
214
215 spin_lock_irqsave(&vc->lock, flags);
216
217 /* Halt the channel */
218 val = readl(mc->reg_ch_base + M10V_XDDES);
219 val &= ~M10V_XDDES_CE;
220 val |= FIELD_PREP(M10V_XDDES_CE, 0);
221 writel(val, mc->reg_ch_base + M10V_XDDES);
222
223 if (mc->md) {
224 vchan_terminate_vdesc(&mc->md->vd);
225 mc->md = NULL;
226 }
227
228 vchan_get_all_descriptors(vc, &head);
229
230 spin_unlock_irqrestore(&vc->lock, flags);
231
232 vchan_dma_desc_free_list(vc, &head);
233
234 return 0;
235 }
236
milbeaut_xdmac_synchronize(struct dma_chan * chan)237 static void milbeaut_xdmac_synchronize(struct dma_chan *chan)
238 {
239 vchan_synchronize(to_virt_chan(chan));
240 }
241
milbeaut_xdmac_issue_pending(struct dma_chan * chan)242 static void milbeaut_xdmac_issue_pending(struct dma_chan *chan)
243 {
244 struct virt_dma_chan *vc = to_virt_chan(chan);
245 struct milbeaut_xdmac_chan *mc = to_milbeaut_xdmac_chan(vc);
246 unsigned long flags;
247
248 spin_lock_irqsave(&vc->lock, flags);
249
250 if (vchan_issue_pending(vc) && !mc->md)
251 milbeaut_xdmac_start(mc);
252
253 spin_unlock_irqrestore(&vc->lock, flags);
254 }
255
milbeaut_xdmac_desc_free(struct virt_dma_desc * vd)256 static void milbeaut_xdmac_desc_free(struct virt_dma_desc *vd)
257 {
258 kfree(to_milbeaut_xdmac_desc(vd));
259 }
260
milbeaut_xdmac_chan_init(struct platform_device * pdev,struct milbeaut_xdmac_device * mdev,int chan_id)261 static int milbeaut_xdmac_chan_init(struct platform_device *pdev,
262 struct milbeaut_xdmac_device *mdev,
263 int chan_id)
264 {
265 struct device *dev = &pdev->dev;
266 struct milbeaut_xdmac_chan *mc = &mdev->channels[chan_id];
267 char *irq_name;
268 int irq, ret;
269
270 irq = platform_get_irq(pdev, chan_id);
271 if (irq < 0)
272 return irq;
273
274 irq_name = devm_kasprintf(dev, GFP_KERNEL, "milbeaut-xdmac-%d",
275 chan_id);
276 if (!irq_name)
277 return -ENOMEM;
278
279 ret = devm_request_irq(dev, irq, milbeaut_xdmac_interrupt,
280 IRQF_SHARED, irq_name, mc);
281 if (ret)
282 return ret;
283
284 mc->reg_ch_base = mdev->reg_base + chan_id * 0x30;
285
286 mc->vc.desc_free = milbeaut_xdmac_desc_free;
287 vchan_init(&mc->vc, &mdev->ddev);
288
289 return 0;
290 }
291
enable_xdmac(struct milbeaut_xdmac_device * mdev)292 static void enable_xdmac(struct milbeaut_xdmac_device *mdev)
293 {
294 unsigned int val;
295
296 val = readl(mdev->reg_base + M10V_XDACS);
297 val |= M10V_XDACS_XE;
298 writel(val, mdev->reg_base + M10V_XDACS);
299 }
300
disable_xdmac(struct milbeaut_xdmac_device * mdev)301 static void disable_xdmac(struct milbeaut_xdmac_device *mdev)
302 {
303 unsigned int val;
304
305 val = readl(mdev->reg_base + M10V_XDACS);
306 val &= ~M10V_XDACS_XE;
307 writel(val, mdev->reg_base + M10V_XDACS);
308 }
309
milbeaut_xdmac_probe(struct platform_device * pdev)310 static int milbeaut_xdmac_probe(struct platform_device *pdev)
311 {
312 struct device *dev = &pdev->dev;
313 struct milbeaut_xdmac_device *mdev;
314 struct dma_device *ddev;
315 int nr_chans, ret, i;
316
317 nr_chans = platform_irq_count(pdev);
318 if (nr_chans < 0)
319 return nr_chans;
320
321 mdev = devm_kzalloc(dev, struct_size(mdev, channels, nr_chans),
322 GFP_KERNEL);
323 if (!mdev)
324 return -ENOMEM;
325
326 mdev->reg_base = devm_platform_ioremap_resource(pdev, 0);
327 if (IS_ERR(mdev->reg_base))
328 return PTR_ERR(mdev->reg_base);
329
330 ddev = &mdev->ddev;
331 ddev->dev = dev;
332 dma_cap_set(DMA_MEMCPY, ddev->cap_mask);
333 ddev->src_addr_widths = MLB_XDMAC_BUSWIDTHS;
334 ddev->dst_addr_widths = MLB_XDMAC_BUSWIDTHS;
335 ddev->device_free_chan_resources = milbeaut_xdmac_free_chan_resources;
336 ddev->device_prep_dma_memcpy = milbeaut_xdmac_prep_memcpy;
337 ddev->device_terminate_all = milbeaut_xdmac_terminate_all;
338 ddev->device_synchronize = milbeaut_xdmac_synchronize;
339 ddev->device_tx_status = dma_cookie_status;
340 ddev->device_issue_pending = milbeaut_xdmac_issue_pending;
341 INIT_LIST_HEAD(&ddev->channels);
342
343 for (i = 0; i < nr_chans; i++) {
344 ret = milbeaut_xdmac_chan_init(pdev, mdev, i);
345 if (ret)
346 return ret;
347 }
348
349 enable_xdmac(mdev);
350
351 ret = dma_async_device_register(ddev);
352 if (ret)
353 goto disable_xdmac;
354
355 ret = of_dma_controller_register(dev->of_node,
356 of_dma_simple_xlate, mdev);
357 if (ret)
358 goto unregister_dmac;
359
360 platform_set_drvdata(pdev, mdev);
361
362 return 0;
363
364 unregister_dmac:
365 dma_async_device_unregister(ddev);
366 disable_xdmac:
367 disable_xdmac(mdev);
368 return ret;
369 }
370
milbeaut_xdmac_remove(struct platform_device * pdev)371 static void milbeaut_xdmac_remove(struct platform_device *pdev)
372 {
373 struct milbeaut_xdmac_device *mdev = platform_get_drvdata(pdev);
374 struct dma_chan *chan;
375 int ret;
376
377 /*
378 * Before reaching here, almost all descriptors have been freed by the
379 * ->device_free_chan_resources() hook. However, each channel might
380 * be still holding one descriptor that was on-flight at that moment.
381 * Terminate it to make sure this hardware is no longer running. Then,
382 * free the channel resources once again to avoid memory leak.
383 */
384 list_for_each_entry(chan, &mdev->ddev.channels, device_node) {
385 ret = dmaengine_terminate_sync(chan);
386 if (ret) {
387 /*
388 * This results in resource leakage and maybe also
389 * use-after-free errors as e.g. *mdev is kfreed.
390 */
391 dev_alert(&pdev->dev, "Failed to terminate channel %d (%pe)\n",
392 chan->chan_id, ERR_PTR(ret));
393 return;
394 }
395 milbeaut_xdmac_free_chan_resources(chan);
396 }
397
398 of_dma_controller_free(pdev->dev.of_node);
399 dma_async_device_unregister(&mdev->ddev);
400
401 disable_xdmac(mdev);
402 }
403
404 static const struct of_device_id milbeaut_xdmac_match[] = {
405 { .compatible = "socionext,milbeaut-m10v-xdmac" },
406 { /* sentinel */ }
407 };
408 MODULE_DEVICE_TABLE(of, milbeaut_xdmac_match);
409
410 static struct platform_driver milbeaut_xdmac_driver = {
411 .probe = milbeaut_xdmac_probe,
412 .remove_new = milbeaut_xdmac_remove,
413 .driver = {
414 .name = "milbeaut-m10v-xdmac",
415 .of_match_table = milbeaut_xdmac_match,
416 },
417 };
418 module_platform_driver(milbeaut_xdmac_driver);
419
420 MODULE_DESCRIPTION("Milbeaut XDMAC DmaEngine driver");
421 MODULE_LICENSE("GPL v2");
422