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
61struct 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
68struct milbeaut_xdmac_chan {
69 struct virt_dma_chan vc;
70 struct milbeaut_xdmac_desc *md;
71 void __iomem *reg_ch_base;
72};
73
74struct milbeaut_xdmac_device {
75 struct dma_device ddev;
76 void __iomem *reg_base;
77 struct milbeaut_xdmac_chan channels[];
78};
79
80static struct milbeaut_xdmac_chan *
81to_milbeaut_xdmac_chan(struct virt_dma_chan *vc)
82{
83 return container_of(vc, struct milbeaut_xdmac_chan, vc);
84}
85
86static struct milbeaut_xdmac_desc *
87to_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 */
93static struct milbeaut_xdmac_desc *
94milbeaut_xdmac_next_desc(struct milbeaut_xdmac_chan *mc)
95{
96 struct virt_dma_desc *vd;
97
98 vd = vchan_next_desc(vc: &mc->vc);
99 if (!vd) {
100 mc->md = NULL;
101 return NULL;
102 }
103
104 list_del(entry: &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 */
112static 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 */
150static 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
159static 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(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(vd: &md->vd);
176
177 milbeaut_xdmac_start(mc);
178out:
179 spin_unlock(lock: &mc->vc.lock);
180 return IRQ_HANDLED;
181}
182
183static void milbeaut_xdmac_free_chan_resources(struct dma_chan *chan)
184{
185 vchan_free_chan_resources(vc: to_virt_chan(chan));
186}
187
188static struct dma_async_tx_descriptor *
189milbeaut_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(size: 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, vd: &md->vd, tx_flags: flags);
204}
205
206static 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(addr: mc->reg_ch_base + M10V_XDDES);
219 val &= ~M10V_XDDES_CE;
220 val |= FIELD_PREP(M10V_XDDES_CE, 0);
221 writel(val, addr: mc->reg_ch_base + M10V_XDDES);
222
223 if (mc->md) {
224 vchan_terminate_vdesc(vd: &mc->md->vd);
225 mc->md = NULL;
226 }
227
228 vchan_get_all_descriptors(vc, head: &head);
229
230 spin_unlock_irqrestore(lock: &vc->lock, flags);
231
232 vchan_dma_desc_free_list(vc, head: &head);
233
234 return 0;
235}
236
237static void milbeaut_xdmac_synchronize(struct dma_chan *chan)
238{
239 vchan_synchronize(vc: to_virt_chan(chan));
240}
241
242static 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(lock: &vc->lock, flags);
254}
255
256static void milbeaut_xdmac_desc_free(struct virt_dma_desc *vd)
257{
258 kfree(objp: to_milbeaut_xdmac_desc(vd));
259}
260
261static 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, fmt: "milbeaut-xdmac-%d",
275 chan_id);
276 if (!irq_name)
277 return -ENOMEM;
278
279 ret = devm_request_irq(dev, irq, handler: milbeaut_xdmac_interrupt,
280 IRQF_SHARED, devname: irq_name, dev_id: 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(vc: &mc->vc, dmadev: &mdev->ddev);
288
289 return 0;
290}
291
292static void enable_xdmac(struct milbeaut_xdmac_device *mdev)
293{
294 unsigned int val;
295
296 val = readl(addr: mdev->reg_base + M10V_XDACS);
297 val |= M10V_XDACS_XE;
298 writel(val, addr: mdev->reg_base + M10V_XDACS);
299}
300
301static void disable_xdmac(struct milbeaut_xdmac_device *mdev)
302{
303 unsigned int val;
304
305 val = readl(addr: mdev->reg_base + M10V_XDACS);
306 val &= ~M10V_XDACS_XE;
307 writel(val, addr: mdev->reg_base + M10V_XDACS);
308}
309
310static 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, index: 0);
327 if (IS_ERR(ptr: mdev->reg_base))
328 return PTR_ERR(ptr: 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(list: &ddev->channels);
342
343 for (i = 0; i < nr_chans; i++) {
344 ret = milbeaut_xdmac_chan_init(pdev, mdev, chan_id: i);
345 if (ret)
346 return ret;
347 }
348
349 enable_xdmac(mdev);
350
351 ret = dma_async_device_register(device: ddev);
352 if (ret)
353 goto disable_xdmac;
354
355 ret = of_dma_controller_register(np: dev->of_node,
356 of_dma_xlate: of_dma_simple_xlate, data: mdev);
357 if (ret)
358 goto unregister_dmac;
359
360 platform_set_drvdata(pdev, data: mdev);
361
362 return 0;
363
364unregister_dmac:
365 dma_async_device_unregister(device: ddev);
366disable_xdmac:
367 disable_xdmac(mdev);
368 return ret;
369}
370
371static int 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 return ret;
388 milbeaut_xdmac_free_chan_resources(chan);
389 }
390
391 of_dma_controller_free(np: pdev->dev.of_node);
392 dma_async_device_unregister(device: &mdev->ddev);
393
394 disable_xdmac(mdev);
395
396 return 0;
397}
398
399static const struct of_device_id milbeaut_xdmac_match[] = {
400 { .compatible = "socionext,milbeaut-m10v-xdmac" },
401 { /* sentinel */ }
402};
403MODULE_DEVICE_TABLE(of, milbeaut_xdmac_match);
404
405static struct platform_driver milbeaut_xdmac_driver = {
406 .probe = milbeaut_xdmac_probe,
407 .remove = milbeaut_xdmac_remove,
408 .driver = {
409 .name = "milbeaut-m10v-xdmac",
410 .of_match_table = milbeaut_xdmac_match,
411 },
412};
413module_platform_driver(milbeaut_xdmac_driver);
414
415MODULE_DESCRIPTION("Milbeaut XDMAC DmaEngine driver");
416MODULE_LICENSE("GPL v2");
417

source code of linux/drivers/dma/milbeaut-xdmac.c