1 // SPDX-License-Identifier: GPL-2.0+
2 // Copyright (c) 2018 MediaTek Inc.
3
4 #include <linux/clk.h>
5 #include <linux/device.h>
6 #include <linux/dma-mapping.h>
7 #include <linux/err.h>
8 #include <linux/interrupt.h>
9 #include <linux/module.h>
10 #include <linux/platform_device.h>
11 #include <linux/pm_runtime.h>
12 #include <linux/spi/spi.h>
13
14 #define SPIS_IRQ_EN_REG 0x0
15 #define SPIS_IRQ_CLR_REG 0x4
16 #define SPIS_IRQ_ST_REG 0x8
17 #define SPIS_IRQ_MASK_REG 0xc
18 #define SPIS_CFG_REG 0x10
19 #define SPIS_RX_DATA_REG 0x14
20 #define SPIS_TX_DATA_REG 0x18
21 #define SPIS_RX_DST_REG 0x1c
22 #define SPIS_TX_SRC_REG 0x20
23 #define SPIS_DMA_CFG_REG 0x30
24 #define SPIS_SOFT_RST_REG 0x40
25
26 /* SPIS_IRQ_EN_REG */
27 #define DMA_DONE_EN BIT(7)
28 #define DATA_DONE_EN BIT(2)
29 #define RSTA_DONE_EN BIT(1)
30 #define CMD_INVALID_EN BIT(0)
31
32 /* SPIS_IRQ_ST_REG */
33 #define DMA_DONE_ST BIT(7)
34 #define DATA_DONE_ST BIT(2)
35 #define RSTA_DONE_ST BIT(1)
36 #define CMD_INVALID_ST BIT(0)
37
38 /* SPIS_IRQ_MASK_REG */
39 #define DMA_DONE_MASK BIT(7)
40 #define DATA_DONE_MASK BIT(2)
41 #define RSTA_DONE_MASK BIT(1)
42 #define CMD_INVALID_MASK BIT(0)
43
44 /* SPIS_CFG_REG */
45 #define SPIS_TX_ENDIAN BIT(7)
46 #define SPIS_RX_ENDIAN BIT(6)
47 #define SPIS_TXMSBF BIT(5)
48 #define SPIS_RXMSBF BIT(4)
49 #define SPIS_CPHA BIT(3)
50 #define SPIS_CPOL BIT(2)
51 #define SPIS_TX_EN BIT(1)
52 #define SPIS_RX_EN BIT(0)
53
54 /* SPIS_DMA_CFG_REG */
55 #define TX_DMA_TRIG_EN BIT(31)
56 #define TX_DMA_EN BIT(30)
57 #define RX_DMA_EN BIT(29)
58 #define TX_DMA_LEN 0xfffff
59
60 /* SPIS_SOFT_RST_REG */
61 #define SPIS_DMA_ADDR_EN BIT(1)
62 #define SPIS_SOFT_RST BIT(0)
63
64 #define MTK_SPI_SLAVE_MAX_FIFO_SIZE 512U
65
66 struct mtk_spi_slave {
67 struct device *dev;
68 void __iomem *base;
69 struct clk *spi_clk;
70 struct completion xfer_done;
71 struct spi_transfer *cur_transfer;
72 bool slave_aborted;
73 };
74
75 static const struct of_device_id mtk_spi_slave_of_match[] = {
76 { .compatible = "mediatek,mt2712-spi-slave", },
77 {}
78 };
79 MODULE_DEVICE_TABLE(of, mtk_spi_slave_of_match);
80
mtk_spi_slave_disable_dma(struct mtk_spi_slave * mdata)81 static void mtk_spi_slave_disable_dma(struct mtk_spi_slave *mdata)
82 {
83 u32 reg_val;
84
85 reg_val = readl(mdata->base + SPIS_DMA_CFG_REG);
86 reg_val &= ~RX_DMA_EN;
87 reg_val &= ~TX_DMA_EN;
88 writel(reg_val, mdata->base + SPIS_DMA_CFG_REG);
89 }
90
mtk_spi_slave_disable_xfer(struct mtk_spi_slave * mdata)91 static void mtk_spi_slave_disable_xfer(struct mtk_spi_slave *mdata)
92 {
93 u32 reg_val;
94
95 reg_val = readl(mdata->base + SPIS_CFG_REG);
96 reg_val &= ~SPIS_TX_EN;
97 reg_val &= ~SPIS_RX_EN;
98 writel(reg_val, mdata->base + SPIS_CFG_REG);
99 }
100
mtk_spi_slave_wait_for_completion(struct mtk_spi_slave * mdata)101 static int mtk_spi_slave_wait_for_completion(struct mtk_spi_slave *mdata)
102 {
103 if (wait_for_completion_interruptible(&mdata->xfer_done) ||
104 mdata->slave_aborted) {
105 dev_err(mdata->dev, "interrupted\n");
106 return -EINTR;
107 }
108
109 return 0;
110 }
111
mtk_spi_slave_prepare_message(struct spi_controller * ctlr,struct spi_message * msg)112 static int mtk_spi_slave_prepare_message(struct spi_controller *ctlr,
113 struct spi_message *msg)
114 {
115 struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
116 struct spi_device *spi = msg->spi;
117 bool cpha, cpol;
118 u32 reg_val;
119
120 cpha = spi->mode & SPI_CPHA ? 1 : 0;
121 cpol = spi->mode & SPI_CPOL ? 1 : 0;
122
123 reg_val = readl(mdata->base + SPIS_CFG_REG);
124 if (cpha)
125 reg_val |= SPIS_CPHA;
126 else
127 reg_val &= ~SPIS_CPHA;
128 if (cpol)
129 reg_val |= SPIS_CPOL;
130 else
131 reg_val &= ~SPIS_CPOL;
132
133 if (spi->mode & SPI_LSB_FIRST)
134 reg_val &= ~(SPIS_TXMSBF | SPIS_RXMSBF);
135 else
136 reg_val |= SPIS_TXMSBF | SPIS_RXMSBF;
137
138 reg_val &= ~SPIS_TX_ENDIAN;
139 reg_val &= ~SPIS_RX_ENDIAN;
140 writel(reg_val, mdata->base + SPIS_CFG_REG);
141
142 return 0;
143 }
144
mtk_spi_slave_fifo_transfer(struct spi_controller * ctlr,struct spi_device * spi,struct spi_transfer * xfer)145 static int mtk_spi_slave_fifo_transfer(struct spi_controller *ctlr,
146 struct spi_device *spi,
147 struct spi_transfer *xfer)
148 {
149 struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
150 int reg_val, cnt, remainder, ret;
151
152 writel(SPIS_SOFT_RST, mdata->base + SPIS_SOFT_RST_REG);
153
154 reg_val = readl(mdata->base + SPIS_CFG_REG);
155 if (xfer->rx_buf)
156 reg_val |= SPIS_RX_EN;
157 if (xfer->tx_buf)
158 reg_val |= SPIS_TX_EN;
159 writel(reg_val, mdata->base + SPIS_CFG_REG);
160
161 cnt = xfer->len / 4;
162 if (xfer->tx_buf)
163 iowrite32_rep(mdata->base + SPIS_TX_DATA_REG,
164 xfer->tx_buf, cnt);
165
166 remainder = xfer->len % 4;
167 if (xfer->tx_buf && remainder > 0) {
168 reg_val = 0;
169 memcpy(®_val, xfer->tx_buf + cnt * 4, remainder);
170 writel(reg_val, mdata->base + SPIS_TX_DATA_REG);
171 }
172
173 ret = mtk_spi_slave_wait_for_completion(mdata);
174 if (ret) {
175 mtk_spi_slave_disable_xfer(mdata);
176 writel(SPIS_SOFT_RST, mdata->base + SPIS_SOFT_RST_REG);
177 }
178
179 return ret;
180 }
181
mtk_spi_slave_dma_transfer(struct spi_controller * ctlr,struct spi_device * spi,struct spi_transfer * xfer)182 static int mtk_spi_slave_dma_transfer(struct spi_controller *ctlr,
183 struct spi_device *spi,
184 struct spi_transfer *xfer)
185 {
186 struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
187 struct device *dev = mdata->dev;
188 int reg_val, ret;
189
190 writel(SPIS_SOFT_RST, mdata->base + SPIS_SOFT_RST_REG);
191
192 if (xfer->tx_buf) {
193 /* tx_buf is a const void* where we need a void * for
194 * the dma mapping
195 */
196 void *nonconst_tx = (void *)xfer->tx_buf;
197
198 xfer->tx_dma = dma_map_single(dev, nonconst_tx,
199 xfer->len, DMA_TO_DEVICE);
200 if (dma_mapping_error(dev, xfer->tx_dma)) {
201 ret = -ENOMEM;
202 goto disable_transfer;
203 }
204 }
205
206 if (xfer->rx_buf) {
207 xfer->rx_dma = dma_map_single(dev, xfer->rx_buf,
208 xfer->len, DMA_FROM_DEVICE);
209 if (dma_mapping_error(dev, xfer->rx_dma)) {
210 ret = -ENOMEM;
211 goto unmap_txdma;
212 }
213 }
214
215 writel(xfer->tx_dma, mdata->base + SPIS_TX_SRC_REG);
216 writel(xfer->rx_dma, mdata->base + SPIS_RX_DST_REG);
217
218 writel(SPIS_DMA_ADDR_EN, mdata->base + SPIS_SOFT_RST_REG);
219
220 /* enable config reg tx rx_enable */
221 reg_val = readl(mdata->base + SPIS_CFG_REG);
222 if (xfer->tx_buf)
223 reg_val |= SPIS_TX_EN;
224 if (xfer->rx_buf)
225 reg_val |= SPIS_RX_EN;
226 writel(reg_val, mdata->base + SPIS_CFG_REG);
227
228 /* config dma */
229 reg_val = 0;
230 reg_val |= (xfer->len - 1) & TX_DMA_LEN;
231 writel(reg_val, mdata->base + SPIS_DMA_CFG_REG);
232
233 reg_val = readl(mdata->base + SPIS_DMA_CFG_REG);
234 if (xfer->tx_buf)
235 reg_val |= TX_DMA_EN;
236 if (xfer->rx_buf)
237 reg_val |= RX_DMA_EN;
238 reg_val |= TX_DMA_TRIG_EN;
239 writel(reg_val, mdata->base + SPIS_DMA_CFG_REG);
240
241 ret = mtk_spi_slave_wait_for_completion(mdata);
242 if (ret)
243 goto unmap_rxdma;
244
245 return 0;
246
247 unmap_rxdma:
248 if (xfer->rx_buf)
249 dma_unmap_single(dev, xfer->rx_dma,
250 xfer->len, DMA_FROM_DEVICE);
251
252 unmap_txdma:
253 if (xfer->tx_buf)
254 dma_unmap_single(dev, xfer->tx_dma,
255 xfer->len, DMA_TO_DEVICE);
256
257 disable_transfer:
258 mtk_spi_slave_disable_dma(mdata);
259 mtk_spi_slave_disable_xfer(mdata);
260 writel(SPIS_SOFT_RST, mdata->base + SPIS_SOFT_RST_REG);
261
262 return ret;
263 }
264
mtk_spi_slave_transfer_one(struct spi_controller * ctlr,struct spi_device * spi,struct spi_transfer * xfer)265 static int mtk_spi_slave_transfer_one(struct spi_controller *ctlr,
266 struct spi_device *spi,
267 struct spi_transfer *xfer)
268 {
269 struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
270
271 reinit_completion(&mdata->xfer_done);
272 mdata->slave_aborted = false;
273 mdata->cur_transfer = xfer;
274
275 if (xfer->len > MTK_SPI_SLAVE_MAX_FIFO_SIZE)
276 return mtk_spi_slave_dma_transfer(ctlr, spi, xfer);
277 else
278 return mtk_spi_slave_fifo_transfer(ctlr, spi, xfer);
279 }
280
mtk_spi_slave_setup(struct spi_device * spi)281 static int mtk_spi_slave_setup(struct spi_device *spi)
282 {
283 struct mtk_spi_slave *mdata = spi_controller_get_devdata(spi->master);
284 u32 reg_val;
285
286 reg_val = DMA_DONE_EN | DATA_DONE_EN |
287 RSTA_DONE_EN | CMD_INVALID_EN;
288 writel(reg_val, mdata->base + SPIS_IRQ_EN_REG);
289
290 reg_val = DMA_DONE_MASK | DATA_DONE_MASK |
291 RSTA_DONE_MASK | CMD_INVALID_MASK;
292 writel(reg_val, mdata->base + SPIS_IRQ_MASK_REG);
293
294 mtk_spi_slave_disable_dma(mdata);
295 mtk_spi_slave_disable_xfer(mdata);
296
297 return 0;
298 }
299
mtk_slave_abort(struct spi_controller * ctlr)300 static int mtk_slave_abort(struct spi_controller *ctlr)
301 {
302 struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
303
304 mdata->slave_aborted = true;
305 complete(&mdata->xfer_done);
306
307 return 0;
308 }
309
mtk_spi_slave_interrupt(int irq,void * dev_id)310 static irqreturn_t mtk_spi_slave_interrupt(int irq, void *dev_id)
311 {
312 struct spi_controller *ctlr = dev_id;
313 struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
314 struct spi_transfer *trans = mdata->cur_transfer;
315 u32 int_status, reg_val, cnt, remainder;
316
317 int_status = readl(mdata->base + SPIS_IRQ_ST_REG);
318 writel(int_status, mdata->base + SPIS_IRQ_CLR_REG);
319
320 if (!trans)
321 return IRQ_NONE;
322
323 if ((int_status & DMA_DONE_ST) &&
324 ((int_status & DATA_DONE_ST) ||
325 (int_status & RSTA_DONE_ST))) {
326 writel(SPIS_SOFT_RST, mdata->base + SPIS_SOFT_RST_REG);
327
328 if (trans->tx_buf)
329 dma_unmap_single(mdata->dev, trans->tx_dma,
330 trans->len, DMA_TO_DEVICE);
331 if (trans->rx_buf)
332 dma_unmap_single(mdata->dev, trans->rx_dma,
333 trans->len, DMA_FROM_DEVICE);
334
335 mtk_spi_slave_disable_dma(mdata);
336 mtk_spi_slave_disable_xfer(mdata);
337 }
338
339 if ((!(int_status & DMA_DONE_ST)) &&
340 ((int_status & DATA_DONE_ST) ||
341 (int_status & RSTA_DONE_ST))) {
342 cnt = trans->len / 4;
343 if (trans->rx_buf)
344 ioread32_rep(mdata->base + SPIS_RX_DATA_REG,
345 trans->rx_buf, cnt);
346 remainder = trans->len % 4;
347 if (trans->rx_buf && remainder > 0) {
348 reg_val = readl(mdata->base + SPIS_RX_DATA_REG);
349 memcpy(trans->rx_buf + (cnt * 4),
350 ®_val, remainder);
351 }
352
353 mtk_spi_slave_disable_xfer(mdata);
354 }
355
356 if (int_status & CMD_INVALID_ST) {
357 dev_warn(&ctlr->dev, "cmd invalid\n");
358 return IRQ_NONE;
359 }
360
361 mdata->cur_transfer = NULL;
362 complete(&mdata->xfer_done);
363
364 return IRQ_HANDLED;
365 }
366
mtk_spi_slave_probe(struct platform_device * pdev)367 static int mtk_spi_slave_probe(struct platform_device *pdev)
368 {
369 struct spi_controller *ctlr;
370 struct mtk_spi_slave *mdata;
371 struct resource *res;
372 int irq, ret;
373
374 ctlr = spi_alloc_slave(&pdev->dev, sizeof(*mdata));
375 if (!ctlr) {
376 dev_err(&pdev->dev, "failed to alloc spi slave\n");
377 return -ENOMEM;
378 }
379
380 ctlr->auto_runtime_pm = true;
381 ctlr->dev.of_node = pdev->dev.of_node;
382 ctlr->mode_bits = SPI_CPOL | SPI_CPHA;
383 ctlr->mode_bits |= SPI_LSB_FIRST;
384
385 ctlr->prepare_message = mtk_spi_slave_prepare_message;
386 ctlr->transfer_one = mtk_spi_slave_transfer_one;
387 ctlr->setup = mtk_spi_slave_setup;
388 ctlr->slave_abort = mtk_slave_abort;
389
390 mdata = spi_controller_get_devdata(ctlr);
391
392 platform_set_drvdata(pdev, ctlr);
393
394 init_completion(&mdata->xfer_done);
395
396 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
397 if (!res) {
398 ret = -ENODEV;
399 dev_err(&pdev->dev, "failed to determine base address\n");
400 goto err_put_ctlr;
401 }
402
403 mdata->dev = &pdev->dev;
404
405 mdata->base = devm_ioremap_resource(&pdev->dev, res);
406 if (IS_ERR(mdata->base)) {
407 ret = PTR_ERR(mdata->base);
408 goto err_put_ctlr;
409 }
410
411 irq = platform_get_irq(pdev, 0);
412 if (irq < 0) {
413 ret = irq;
414 goto err_put_ctlr;
415 }
416
417 ret = devm_request_irq(&pdev->dev, irq, mtk_spi_slave_interrupt,
418 IRQF_TRIGGER_NONE, dev_name(&pdev->dev), ctlr);
419 if (ret) {
420 dev_err(&pdev->dev, "failed to register irq (%d)\n", ret);
421 goto err_put_ctlr;
422 }
423
424 mdata->spi_clk = devm_clk_get(&pdev->dev, "spi");
425 if (IS_ERR(mdata->spi_clk)) {
426 ret = PTR_ERR(mdata->spi_clk);
427 dev_err(&pdev->dev, "failed to get spi-clk: %d\n", ret);
428 goto err_put_ctlr;
429 }
430
431 ret = clk_prepare_enable(mdata->spi_clk);
432 if (ret < 0) {
433 dev_err(&pdev->dev, "failed to enable spi_clk (%d)\n", ret);
434 goto err_put_ctlr;
435 }
436
437 pm_runtime_enable(&pdev->dev);
438
439 ret = devm_spi_register_controller(&pdev->dev, ctlr);
440 if (ret) {
441 dev_err(&pdev->dev,
442 "failed to register slave controller(%d)\n", ret);
443 clk_disable_unprepare(mdata->spi_clk);
444 goto err_disable_runtime_pm;
445 }
446
447 clk_disable_unprepare(mdata->spi_clk);
448
449 return 0;
450
451 err_disable_runtime_pm:
452 pm_runtime_disable(&pdev->dev);
453 err_put_ctlr:
454 spi_controller_put(ctlr);
455
456 return ret;
457 }
458
mtk_spi_slave_remove(struct platform_device * pdev)459 static int mtk_spi_slave_remove(struct platform_device *pdev)
460 {
461 pm_runtime_disable(&pdev->dev);
462
463 return 0;
464 }
465
466 #ifdef CONFIG_PM_SLEEP
mtk_spi_slave_suspend(struct device * dev)467 static int mtk_spi_slave_suspend(struct device *dev)
468 {
469 struct spi_controller *ctlr = dev_get_drvdata(dev);
470 struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
471 int ret;
472
473 ret = spi_controller_suspend(ctlr);
474 if (ret)
475 return ret;
476
477 if (!pm_runtime_suspended(dev))
478 clk_disable_unprepare(mdata->spi_clk);
479
480 return ret;
481 }
482
mtk_spi_slave_resume(struct device * dev)483 static int mtk_spi_slave_resume(struct device *dev)
484 {
485 struct spi_controller *ctlr = dev_get_drvdata(dev);
486 struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
487 int ret;
488
489 if (!pm_runtime_suspended(dev)) {
490 ret = clk_prepare_enable(mdata->spi_clk);
491 if (ret < 0) {
492 dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
493 return ret;
494 }
495 }
496
497 ret = spi_controller_resume(ctlr);
498 if (ret < 0)
499 clk_disable_unprepare(mdata->spi_clk);
500
501 return ret;
502 }
503 #endif /* CONFIG_PM_SLEEP */
504
505 #ifdef CONFIG_PM
mtk_spi_slave_runtime_suspend(struct device * dev)506 static int mtk_spi_slave_runtime_suspend(struct device *dev)
507 {
508 struct spi_controller *ctlr = dev_get_drvdata(dev);
509 struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
510
511 clk_disable_unprepare(mdata->spi_clk);
512
513 return 0;
514 }
515
mtk_spi_slave_runtime_resume(struct device * dev)516 static int mtk_spi_slave_runtime_resume(struct device *dev)
517 {
518 struct spi_controller *ctlr = dev_get_drvdata(dev);
519 struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
520 int ret;
521
522 ret = clk_prepare_enable(mdata->spi_clk);
523 if (ret < 0) {
524 dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
525 return ret;
526 }
527
528 return 0;
529 }
530 #endif /* CONFIG_PM */
531
532 static const struct dev_pm_ops mtk_spi_slave_pm = {
533 SET_SYSTEM_SLEEP_PM_OPS(mtk_spi_slave_suspend, mtk_spi_slave_resume)
534 SET_RUNTIME_PM_OPS(mtk_spi_slave_runtime_suspend,
535 mtk_spi_slave_runtime_resume, NULL)
536 };
537
538 static struct platform_driver mtk_spi_slave_driver = {
539 .driver = {
540 .name = "mtk-spi-slave",
541 .pm = &mtk_spi_slave_pm,
542 .of_match_table = mtk_spi_slave_of_match,
543 },
544 .probe = mtk_spi_slave_probe,
545 .remove = mtk_spi_slave_remove,
546 };
547
548 module_platform_driver(mtk_spi_slave_driver);
549
550 MODULE_DESCRIPTION("MTK SPI Slave Controller driver");
551 MODULE_AUTHOR("Leilk Liu <leilk.liu@mediatek.com>");
552 MODULE_LICENSE("GPL v2");
553 MODULE_ALIAS("platform:mtk-spi-slave");
554