forked from ~ljy/RK356X_SDK_RELEASE
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hc
2024-10-09 244b2c5ca8b14627e4a17755e5922221e121c771 
 kernel/drivers/spi/spi-uniphier.c
....@@ -7,6 +7,8 @@
77 #include <linux/bitfield.h>
88 #include <linux/bitops.h>
99 #include <linux/clk.h>
10
+#include <linux/delay.h>
11
+#include <linux/dmaengine.h>
1012 #include <linux/interrupt.h>
1113 #include <linux/io.h>
1214 #include <linux/module.h>
....@@ -16,11 +18,13 @@
1618 #include <asm/unaligned.h>
1719 
1820 #define SSI_TIMEOUT_MS		2000
21
+#define SSI_POLL_TIMEOUT_US	200
1922 #define SSI_MAX_CLK_DIVIDER	254
2023 #define SSI_MIN_CLK_DIVIDER	4
2124 
2225 struct uniphier_spi_priv {
2326 	void __iomem *base;
27
+	dma_addr_t base_dma_addr;
2428 	struct clk *clk;
2529 	struct spi_master *master;
2630 	struct completion xfer_done;
....@@ -30,6 +34,7 @@
3034 	unsigned int rx_bytes;
3135 	const u8 *tx_buf;
3236 	u8 *rx_buf;
37
+	atomic_t dma_busy;
3338 
3439 	bool is_save_param;
3540 	u8 bits_per_word;
....@@ -59,11 +64,16 @@
5964 #define   SSI_FPS_FSTRT		BIT(14)
6065 
6166 #define SSI_SR			0x14
67
+#define   SSI_SR_BUSY		BIT(7)
6268 #define   SSI_SR_RNE		BIT(0)
6369 
6470 #define SSI_IE			0x18
71
+#define   SSI_IE_TCIE		BIT(4)
6572 #define   SSI_IE_RCIE		BIT(3)
73
+#define   SSI_IE_TXRE		BIT(2)
74
+#define   SSI_IE_RXRE		BIT(1)
6675 #define   SSI_IE_RORIE		BIT(0)
76
+#define   SSI_IE_ALL_MASK	GENMASK(4, 0)
6777 
6878 #define SSI_IS			0x1c
6979 #define   SSI_IS_RXRS		BIT(9)
....@@ -85,15 +95,19 @@
8595 #define SSI_RXDR		0x24
8696 
8797 #define SSI_FIFO_DEPTH		8U
98
+#define SSI_FIFO_BURST_NUM	1
99
+
100
+#define SSI_DMA_RX_BUSY		BIT(1)
101
+#define SSI_DMA_TX_BUSY		BIT(0)
88102 
89103 static inline unsigned int bytes_per_word(unsigned int bits)
90104 {
91105 	return bits <= 8 ? 1 : (bits <= 16 ? 2 : 4);
92106 }
93107 
94
-static inline void uniphier_spi_irq_enable(struct spi_device *spi, u32 mask)
108
+static inline void uniphier_spi_irq_enable(struct uniphier_spi_priv *priv,
109
+					   u32 mask)
95110 {
96
-	struct uniphier_spi_priv *priv = spi_master_get_devdata(spi->master);
97111 	u32 val;
98112 
99113 	val = readl(priv->base + SSI_IE);
....@@ -101,9 +115,9 @@
101115 	writel(val, priv->base + SSI_IE);
102116 }
103117 
104
-static inline void uniphier_spi_irq_disable(struct spi_device *spi, u32 mask)
118
+static inline void uniphier_spi_irq_disable(struct uniphier_spi_priv *priv,
119
+					    u32 mask)
105120 {
106
-	struct uniphier_spi_priv *priv = spi_master_get_devdata(spi->master);
107121 	u32 val;
108122 
109123 	val = readl(priv->base + SSI_IE);
....@@ -214,6 +228,7 @@
214228 	if (!priv->is_save_param || priv->mode != spi->mode) {
215229 		uniphier_spi_set_mode(spi);
216230 		priv->mode = spi->mode;
231
+		priv->is_save_param = false;
217232 	}
218233 
219234 	if (!priv->is_save_param || priv->bits_per_word != t->bits_per_word) {
....@@ -226,8 +241,7 @@
226241 		priv->speed_hz = t->speed_hz;
227242 	}
228243 
229
-	if (!priv->is_save_param)
230
-		priv->is_save_param = true;
244
+	priv->is_save_param = true;
231245 
232246 	/* reset FIFOs */
233247 	val = SSI_FC_TXFFL | SSI_FC_RXFFL;
....@@ -288,23 +302,32 @@
288302 	}
289303 }
290304 
291
-static void uniphier_spi_fill_tx_fifo(struct uniphier_spi_priv *priv)
305
+static void uniphier_spi_set_fifo_threshold(struct uniphier_spi_priv *priv,
306
+					    unsigned int threshold)
292307 {
293
-	unsigned int tx_count;
294308 	u32 val;
295309 
296
-	tx_count = DIV_ROUND_UP(priv->tx_bytes,
297
-				bytes_per_word(priv->bits_per_word));
298
-	tx_count = min(tx_count, SSI_FIFO_DEPTH);
299
-
300
-	/* set fifo threshold */
301310 	val = readl(priv->base + SSI_FC);
302311 	val &= ~(SSI_FC_TXFTH_MASK | SSI_FC_RXFTH_MASK);
303
-	val |= FIELD_PREP(SSI_FC_TXFTH_MASK, tx_count);
304
-	val |= FIELD_PREP(SSI_FC_RXFTH_MASK, tx_count);
312
+	val |= FIELD_PREP(SSI_FC_TXFTH_MASK, SSI_FIFO_DEPTH - threshold);
313
+	val |= FIELD_PREP(SSI_FC_RXFTH_MASK, threshold);
305314 	writel(val, priv->base + SSI_FC);
315
+}
306316 
307
-	while (tx_count--)
317
+static void uniphier_spi_fill_tx_fifo(struct uniphier_spi_priv *priv)
318
+{
319
+	unsigned int fifo_threshold, fill_words;
320
+	unsigned int bpw = bytes_per_word(priv->bits_per_word);
321
+
322
+	fifo_threshold = DIV_ROUND_UP(priv->rx_bytes, bpw);
323
+	fifo_threshold = min(fifo_threshold, SSI_FIFO_DEPTH);
324
+
325
+	uniphier_spi_set_fifo_threshold(priv, fifo_threshold);
326
+
327
+	fill_words = fifo_threshold -
328
+		DIV_ROUND_UP(priv->rx_bytes - priv->tx_bytes, bpw);
329
+
330
+	while (fill_words--)
308331 		uniphier_spi_send(priv);
309332 }
310333 
....@@ -323,30 +346,211 @@
323346 	writel(val, priv->base + SSI_FPS);
324347 }
325348 
326
-static int uniphier_spi_transfer_one(struct spi_master *master,
327
-				     struct spi_device *spi,
328
-				     struct spi_transfer *t)
349
+static bool uniphier_spi_can_dma(struct spi_master *master,
350
+				 struct spi_device *spi,
351
+				 struct spi_transfer *t)
329352 {
330353 	struct uniphier_spi_priv *priv = spi_master_get_devdata(master);
331
-	int status;
354
+	unsigned int bpw = bytes_per_word(priv->bits_per_word);
332355 
333
-	uniphier_spi_setup_transfer(spi, t);
356
+	if ((!master->dma_tx && !master->dma_rx)
357
+	    || (!master->dma_tx && t->tx_buf)
358
+	    || (!master->dma_rx && t->rx_buf))
359
+		return false;
360
+
361
+	return DIV_ROUND_UP(t->len, bpw) > SSI_FIFO_DEPTH;
362
+}
363
+
364
+static void uniphier_spi_dma_rxcb(void *data)
365
+{
366
+	struct spi_master *master = data;
367
+	struct uniphier_spi_priv *priv = spi_master_get_devdata(master);
368
+	int state = atomic_fetch_andnot(SSI_DMA_RX_BUSY, &priv->dma_busy);
369
+
370
+	uniphier_spi_irq_disable(priv, SSI_IE_RXRE);
371
+
372
+	if (!(state & SSI_DMA_TX_BUSY))
373
+		spi_finalize_current_transfer(master);
374
+}
375
+
376
+static void uniphier_spi_dma_txcb(void *data)
377
+{
378
+	struct spi_master *master = data;
379
+	struct uniphier_spi_priv *priv = spi_master_get_devdata(master);
380
+	int state = atomic_fetch_andnot(SSI_DMA_TX_BUSY, &priv->dma_busy);
381
+
382
+	uniphier_spi_irq_disable(priv, SSI_IE_TXRE);
383
+
384
+	if (!(state & SSI_DMA_RX_BUSY))
385
+		spi_finalize_current_transfer(master);
386
+}
387
+
388
+static int uniphier_spi_transfer_one_dma(struct spi_master *master,
389
+					 struct spi_device *spi,
390
+					 struct spi_transfer *t)
391
+{
392
+	struct uniphier_spi_priv *priv = spi_master_get_devdata(master);
393
+	struct dma_async_tx_descriptor *rxdesc = NULL, *txdesc = NULL;
394
+	int buswidth;
395
+
396
+	atomic_set(&priv->dma_busy, 0);
397
+
398
+	uniphier_spi_set_fifo_threshold(priv, SSI_FIFO_BURST_NUM);
399
+
400
+	if (priv->bits_per_word <= 8)
401
+		buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
402
+	else if (priv->bits_per_word <= 16)
403
+		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
404
+	else
405
+		buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
406
+
407
+	if (priv->rx_buf) {
408
+		struct dma_slave_config rxconf = {
409
+			.direction = DMA_DEV_TO_MEM,
410
+			.src_addr = priv->base_dma_addr + SSI_RXDR,
411
+			.src_addr_width = buswidth,
412
+			.src_maxburst = SSI_FIFO_BURST_NUM,
413
+		};
414
+
415
+		dmaengine_slave_config(master->dma_rx, &rxconf);
416
+
417
+		rxdesc = dmaengine_prep_slave_sg(
418
+			master->dma_rx,
419
+			t->rx_sg.sgl, t->rx_sg.nents,
420
+			DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
421
+		if (!rxdesc)
422
+			goto out_err_prep;
423
+
424
+		rxdesc->callback = uniphier_spi_dma_rxcb;
425
+		rxdesc->callback_param = master;
426
+
427
+		uniphier_spi_irq_enable(priv, SSI_IE_RXRE);
428
+		atomic_or(SSI_DMA_RX_BUSY, &priv->dma_busy);
429
+
430
+		dmaengine_submit(rxdesc);
431
+		dma_async_issue_pending(master->dma_rx);
432
+	}
433
+
434
+	if (priv->tx_buf) {
435
+		struct dma_slave_config txconf = {
436
+			.direction = DMA_MEM_TO_DEV,
437
+			.dst_addr = priv->base_dma_addr + SSI_TXDR,
438
+			.dst_addr_width = buswidth,
439
+			.dst_maxburst = SSI_FIFO_BURST_NUM,
440
+		};
441
+
442
+		dmaengine_slave_config(master->dma_tx, &txconf);
443
+
444
+		txdesc = dmaengine_prep_slave_sg(
445
+			master->dma_tx,
446
+			t->tx_sg.sgl, t->tx_sg.nents,
447
+			DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
448
+		if (!txdesc)
449
+			goto out_err_prep;
450
+
451
+		txdesc->callback = uniphier_spi_dma_txcb;
452
+		txdesc->callback_param = master;
453
+
454
+		uniphier_spi_irq_enable(priv, SSI_IE_TXRE);
455
+		atomic_or(SSI_DMA_TX_BUSY, &priv->dma_busy);
456
+
457
+		dmaengine_submit(txdesc);
458
+		dma_async_issue_pending(master->dma_tx);
459
+	}
460
+
461
+	/* signal that we need to wait for completion */
462
+	return (priv->tx_buf || priv->rx_buf);
463
+
464
+out_err_prep:
465
+	if (rxdesc)
466
+		dmaengine_terminate_sync(master->dma_rx);
467
+
468
+	return -EINVAL;
469
+}
470
+
471
+static int uniphier_spi_transfer_one_irq(struct spi_master *master,
472
+					 struct spi_device *spi,
473
+					 struct spi_transfer *t)
474
+{
475
+	struct uniphier_spi_priv *priv = spi_master_get_devdata(master);
476
+	struct device *dev = master->dev.parent;
477
+	unsigned long time_left;
334478 
335479 	reinit_completion(&priv->xfer_done);
336480 
337481 	uniphier_spi_fill_tx_fifo(priv);
338482 
339
-	uniphier_spi_irq_enable(spi, SSI_IE_RCIE | SSI_IE_RORIE);
483
+	uniphier_spi_irq_enable(priv, SSI_IE_RCIE | SSI_IE_RORIE);
340484 
341
-	status = wait_for_completion_timeout(&priv->xfer_done,
342
-					     msecs_to_jiffies(SSI_TIMEOUT_MS));
485
+	time_left = wait_for_completion_timeout(&priv->xfer_done,
486
+					msecs_to_jiffies(SSI_TIMEOUT_MS));
343487 
344
-	uniphier_spi_irq_disable(spi, SSI_IE_RCIE | SSI_IE_RORIE);
488
+	uniphier_spi_irq_disable(priv, SSI_IE_RCIE | SSI_IE_RORIE);
345489 
346
-	if (status < 0)
347
-		return status;
490
+	if (!time_left) {
491
+		dev_err(dev, "transfer timeout.\n");
492
+		return -ETIMEDOUT;
493
+	}
348494 
349495 	return priv->error;
496
+}
497
+
498
+static int uniphier_spi_transfer_one_poll(struct spi_master *master,
499
+					  struct spi_device *spi,
500
+					  struct spi_transfer *t)
501
+{
502
+	struct uniphier_spi_priv *priv = spi_master_get_devdata(master);
503
+	int loop = SSI_POLL_TIMEOUT_US * 10;
504
+
505
+	while (priv->tx_bytes) {
506
+		uniphier_spi_fill_tx_fifo(priv);
507
+
508
+		while ((priv->rx_bytes - priv->tx_bytes) > 0) {
509
+			while (!(readl(priv->base + SSI_SR) & SSI_SR_RNE)
510
+								&& loop--)
511
+				ndelay(100);
512
+
513
+			if (loop == -1)
514
+				goto irq_transfer;
515
+
516
+			uniphier_spi_recv(priv);
517
+		}
518
+	}
519
+
520
+	return 0;
521
+
522
+irq_transfer:
523
+	return uniphier_spi_transfer_one_irq(master, spi, t);
524
+}
525
+
526
+static int uniphier_spi_transfer_one(struct spi_master *master,
527
+				     struct spi_device *spi,
528
+				     struct spi_transfer *t)
529
+{
530
+	struct uniphier_spi_priv *priv = spi_master_get_devdata(master);
531
+	unsigned long threshold;
532
+	bool use_dma;
533
+
534
+	/* Terminate and return success for 0 byte length transfer */
535
+	if (!t->len)
536
+		return 0;
537
+
538
+	uniphier_spi_setup_transfer(spi, t);
539
+
540
+	use_dma = master->can_dma ? master->can_dma(master, spi, t) : false;
541
+	if (use_dma)
542
+		return uniphier_spi_transfer_one_dma(master, spi, t);
543
+
544
+	/*
545
+	 * If the transfer operation will take longer than
546
+	 * SSI_POLL_TIMEOUT_US, it should use irq.
547
+	 */
548
+	threshold = DIV_ROUND_UP(SSI_POLL_TIMEOUT_US * priv->speed_hz,
549
+					USEC_PER_SEC * BITS_PER_BYTE);
550
+	if (t->len > threshold)
551
+		return uniphier_spi_transfer_one_irq(master, spi, t);
552
+	else
553
+		return uniphier_spi_transfer_one_poll(master, spi, t);
350554 }
351555 
352556 static int uniphier_spi_prepare_transfer_hardware(struct spi_master *master)
....@@ -365,6 +569,32 @@
365569 	writel(0, priv->base + SSI_CTL);
366570 
367571 	return 0;
572
+}
573
+
574
+static void uniphier_spi_handle_err(struct spi_master *master,
575
+				    struct spi_message *msg)
576
+{
577
+	struct uniphier_spi_priv *priv = spi_master_get_devdata(master);
578
+	u32 val;
579
+
580
+	/* stop running spi transfer */
581
+	writel(0, priv->base + SSI_CTL);
582
+
583
+	/* reset FIFOs */
584
+	val = SSI_FC_TXFFL | SSI_FC_RXFFL;
585
+	writel(val, priv->base + SSI_FC);
586
+
587
+	uniphier_spi_irq_disable(priv, SSI_IE_ALL_MASK);
588
+
589
+	if (atomic_read(&priv->dma_busy) & SSI_DMA_TX_BUSY) {
590
+		dmaengine_terminate_async(master->dma_tx);
591
+		atomic_andnot(SSI_DMA_TX_BUSY, &priv->dma_busy);
592
+	}
593
+
594
+	if (atomic_read(&priv->dma_busy) & SSI_DMA_RX_BUSY) {
595
+		dmaengine_terminate_async(master->dma_rx);
596
+		atomic_andnot(SSI_DMA_RX_BUSY, &priv->dma_busy);
597
+	}
368598 }
369599 
370600 static irqreturn_t uniphier_spi_handler(int irq, void *dev_id)
....@@ -413,6 +643,8 @@
413643 	struct uniphier_spi_priv *priv;
414644 	struct spi_master *master;
415645 	struct resource *res;
646
+	struct dma_slave_caps caps;
647
+	u32 dma_tx_burst = 0, dma_rx_burst = 0;
416648 	unsigned long clk_rate;
417649 	int irq;
418650 	int ret;
....@@ -427,12 +659,12 @@
427659 	priv->master = master;
428660 	priv->is_save_param = false;
429661 
430
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
431
-	priv->base = devm_ioremap_resource(&pdev->dev, res);
662
+	priv->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
432663 	if (IS_ERR(priv->base)) {
433664 		ret = PTR_ERR(priv->base);
434665 		goto out_master_put;
435666 	}
667
+	priv->base_dma_addr = res->start;
436668 
437669 	priv->clk = devm_clk_get(&pdev->dev, NULL);
438670 	if (IS_ERR(priv->clk)) {
....@@ -447,7 +679,6 @@
447679 
448680 	irq = platform_get_irq(pdev, 0);
449681 	if (irq < 0) {
450
-		dev_err(&pdev->dev, "failed to get IRQ\n");
451682 		ret = irq;
452683 		goto out_disable_clk;
453684 	}
....@@ -476,13 +707,65 @@
476707 				= uniphier_spi_prepare_transfer_hardware;
477708 	master->unprepare_transfer_hardware
478709 				= uniphier_spi_unprepare_transfer_hardware;
710
+	master->handle_err = uniphier_spi_handle_err;
711
+	master->can_dma = uniphier_spi_can_dma;
712
+
479713 	master->num_chipselect = 1;
714
+	master->flags = SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX;
715
+
716
+	master->dma_tx = dma_request_chan(&pdev->dev, "tx");
717
+	if (IS_ERR_OR_NULL(master->dma_tx)) {
718
+		if (PTR_ERR(master->dma_tx) == -EPROBE_DEFER) {
719
+			ret = -EPROBE_DEFER;
720
+			goto out_disable_clk;
721
+		}
722
+		master->dma_tx = NULL;
723
+		dma_tx_burst = INT_MAX;
724
+	} else {
725
+		ret = dma_get_slave_caps(master->dma_tx, &caps);
726
+		if (ret) {
727
+			dev_err(&pdev->dev, "failed to get TX DMA capacities: %d\n",
728
+				ret);
729
+			goto out_release_dma;
730
+		}
731
+		dma_tx_burst = caps.max_burst;
732
+	}
733
+
734
+	master->dma_rx = dma_request_chan(&pdev->dev, "rx");
735
+	if (IS_ERR_OR_NULL(master->dma_rx)) {
736
+		if (PTR_ERR(master->dma_rx) == -EPROBE_DEFER) {
737
+			ret = -EPROBE_DEFER;
738
+			goto out_release_dma;
739
+		}
740
+		master->dma_rx = NULL;
741
+		dma_rx_burst = INT_MAX;
742
+	} else {
743
+		ret = dma_get_slave_caps(master->dma_rx, &caps);
744
+		if (ret) {
745
+			dev_err(&pdev->dev, "failed to get RX DMA capacities: %d\n",
746
+				ret);
747
+			goto out_release_dma;
748
+		}
749
+		dma_rx_burst = caps.max_burst;
750
+	}
751
+
752
+	master->max_dma_len = min(dma_tx_burst, dma_rx_burst);
480753 
481754 	ret = devm_spi_register_master(&pdev->dev, master);
482755 	if (ret)
483
-		goto out_disable_clk;
756
+		goto out_release_dma;
484757 
485758 	return 0;
759
+
760
+out_release_dma:
761
+	if (!IS_ERR_OR_NULL(master->dma_rx)) {
762
+		dma_release_channel(master->dma_rx);
763
+		master->dma_rx = NULL;
764
+	}
765
+	if (!IS_ERR_OR_NULL(master->dma_tx)) {
766
+		dma_release_channel(master->dma_tx);
767
+		master->dma_tx = NULL;
768
+	}
486769 
487770 out_disable_clk:
488771 	clk_disable_unprepare(priv->clk);
....@@ -494,7 +777,13 @@
494777 
495778 static int uniphier_spi_remove(struct platform_device *pdev)
496779 {
497
-	struct uniphier_spi_priv *priv = platform_get_drvdata(pdev);
780
+	struct spi_master *master = platform_get_drvdata(pdev);
781
+	struct uniphier_spi_priv *priv = spi_master_get_devdata(master);
782
+
783
+	if (master->dma_tx)
784
+		dma_release_channel(master->dma_tx);
785
+	if (master->dma_rx)
786
+		dma_release_channel(master->dma_rx);
498787 
499788 	clk_disable_unprepare(priv->clk);
500789