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2024-10-09 244b2c5ca8b14627e4a17755e5922221e121c771 
 kernel/drivers/i2c/busses/i2c-sh_mobile.c
....@@ -2,8 +2,7 @@
22 /*
33  * SuperH Mobile I2C Controller
44  *
5
- * Copyright (C) 2014 Wolfram Sang <wsa@sang-engineering.com>
6
- *
5
+ * Copyright (C) 2014-19 Wolfram Sang <wsa@sang-engineering.com>
76  * Copyright (C) 2008 Magnus Damm
87  *
98  * Portions of the code based on out-of-tree driver i2c-sh7343.c
....@@ -130,6 +129,7 @@
130129 	int sr;
131130 	bool send_stop;
132131 	bool stop_after_dma;
132
+	bool atomic_xfer;
133133 
134134 	struct resource *res;
135135 	struct dma_chan *dma_tx;
....@@ -145,9 +145,6 @@
145145 };
146146 
147147 #define IIC_FLAG_HAS_ICIC67	(1 << 0)
148
-
149
-#define STANDARD_MODE		100000
150
-#define FAST_MODE		400000
151148 
152149 /* Register offsets */
153150 #define ICDR			0x00
....@@ -271,11 +268,11 @@
271268 
272269 	i2c_clk_khz = clk_get_rate(pd->clk) / 1000 / pd->clks_per_count;
273270 
274
-	if (pd->bus_speed == STANDARD_MODE) {
271
+	if (pd->bus_speed == I2C_MAX_STANDARD_MODE_FREQ) {
275272 		tLOW	= 47;	/* tLOW = 4.7 us */
276273 		tHIGH	= 40;	/* tHD;STA = tHIGH = 4.0 us */
277274 		tf	= 3;	/* tf = 0.3 us */
278
-	} else if (pd->bus_speed == FAST_MODE) {
275
+	} else if (pd->bus_speed == I2C_MAX_FAST_MODE_FREQ) {
279276 		tLOW	= 13;	/* tLOW = 1.3 us */
280277 		tHIGH	= 6;	/* tHD;STA = tHIGH = 0.6 us */
281278 		tf	= 3;	/* tf = 0.3 us */
....@@ -303,13 +300,12 @@
303300 	return sh_mobile_i2c_check_timing(pd);
304301 }
305302 
306
-static unsigned char i2c_op(struct sh_mobile_i2c_data *pd,
307
-			    enum sh_mobile_i2c_op op, unsigned char data)
303
+static unsigned char i2c_op(struct sh_mobile_i2c_data *pd, enum sh_mobile_i2c_op op)
308304 {
309305 	unsigned char ret = 0;
310306 	unsigned long flags;
311307 
312
-	dev_dbg(pd->dev, "op %d, data in 0x%02x\n", op, data);
308
+	dev_dbg(pd->dev, "op %d\n", op);
313309 
314310 	spin_lock_irqsave(&pd->lock, flags);
315311 
....@@ -317,12 +313,12 @@
317313 	case OP_START: /* issue start and trigger DTE interrupt */
318314 		iic_wr(pd, ICCR, ICCR_ICE | ICCR_TRS | ICCR_BBSY);
319315 		break;
320
-	case OP_TX_FIRST: /* disable DTE interrupt and write data */
316
+	case OP_TX_FIRST: /* disable DTE interrupt and write client address */
321317 		iic_wr(pd, ICIC, ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
322
-		iic_wr(pd, ICDR, data);
318
+		iic_wr(pd, ICDR, i2c_8bit_addr_from_msg(pd->msg));
323319 		break;
324320 	case OP_TX: /* write data */
325
-		iic_wr(pd, ICDR, data);
321
+		iic_wr(pd, ICDR, pd->msg->buf[pd->pos]);
326322 		break;
327323 	case OP_TX_STOP: /* issue a stop (or rep_start) */
328324 		iic_wr(pd, ICCR, pd->send_stop ? ICCR_ICE | ICCR_TRS
....@@ -335,13 +331,15 @@
335331 		ret = iic_rd(pd, ICDR);
336332 		break;
337333 	case OP_RX_STOP: /* enable DTE interrupt, issue stop */
338
-		iic_wr(pd, ICIC,
339
-		       ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
334
+		if (!pd->atomic_xfer)
335
+			iic_wr(pd, ICIC,
336
+			       ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
340337 		iic_wr(pd, ICCR, ICCR_ICE | ICCR_RACK);
341338 		break;
342339 	case OP_RX_STOP_DATA: /* enable DTE interrupt, read data, issue stop */
343
-		iic_wr(pd, ICIC,
344
-		       ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
340
+		if (!pd->atomic_xfer)
341
+			iic_wr(pd, ICIC,
342
+			       ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
345343 		ret = iic_rd(pd, ICDR);
346344 		iic_wr(pd, ICCR, ICCR_ICE | ICCR_RACK);
347345 		break;
....@@ -353,34 +351,17 @@
353351 	return ret;
354352 }
355353 
356
-static bool sh_mobile_i2c_is_first_byte(struct sh_mobile_i2c_data *pd)
357
-{
358
-	return pd->pos == -1;
359
-}
360
-
361
-static void sh_mobile_i2c_get_data(struct sh_mobile_i2c_data *pd,
362
-				   unsigned char *buf)
363
-{
364
-	switch (pd->pos) {
365
-	case -1:
366
-		*buf = i2c_8bit_addr_from_msg(pd->msg);
367
-		break;
368
-	default:
369
-		*buf = pd->msg->buf[pd->pos];
370
-	}
371
-}
372
-
373354 static int sh_mobile_i2c_isr_tx(struct sh_mobile_i2c_data *pd)
374355 {
375
-	unsigned char data;
376
-
377356 	if (pd->pos == pd->msg->len) {
378
-		i2c_op(pd, OP_TX_STOP, 0);
357
+		i2c_op(pd, OP_TX_STOP);
379358 		return 1;
380359 	}
381360 
382
-	sh_mobile_i2c_get_data(pd, &data);
383
-	i2c_op(pd, sh_mobile_i2c_is_first_byte(pd) ? OP_TX_FIRST : OP_TX, data);
361
+	if (pd->pos == -1)
362
+		i2c_op(pd, OP_TX_FIRST);
363
+	else
364
+		i2c_op(pd, OP_TX);
384365 
385366 	pd->pos++;
386367 	return 0;
....@@ -388,48 +369,32 @@
388369 
389370 static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd)
390371 {
391
-	unsigned char data;
392372 	int real_pos;
393373 
394
-	do {
395
-		if (pd->pos <= -1) {
396
-			sh_mobile_i2c_get_data(pd, &data);
374
+	/* switch from TX (address) to RX (data) adds two interrupts */
375
+	real_pos = pd->pos - 2;
397376 
398
-			if (sh_mobile_i2c_is_first_byte(pd))
399
-				i2c_op(pd, OP_TX_FIRST, data);
400
-			else
401
-				i2c_op(pd, OP_TX, data);
402
-			break;
377
+	if (pd->pos == -1) {
378
+		i2c_op(pd, OP_TX_FIRST);
379
+	} else if (pd->pos == 0) {
380
+		i2c_op(pd, OP_TX_TO_RX);
381
+	} else if (pd->pos == pd->msg->len) {
382
+		if (pd->stop_after_dma) {
383
+			/* Simulate PIO end condition after DMA transfer */
384
+			i2c_op(pd, OP_RX_STOP);
385
+			pd->pos++;
386
+			goto done;
403387 		}
404388 
405
-		if (pd->pos == 0) {
406
-			i2c_op(pd, OP_TX_TO_RX, 0);
407
-			break;
408
-		}
389
+		if (real_pos < 0)
390
+			i2c_op(pd, OP_RX_STOP);
391
+		else
392
+			pd->msg->buf[real_pos] = i2c_op(pd, OP_RX_STOP_DATA);
393
+	} else if (real_pos >= 0) {
394
+		pd->msg->buf[real_pos] = i2c_op(pd, OP_RX);
395
+	}
409396 
410
-		real_pos = pd->pos - 2;
411
-
412
-		if (pd->pos == pd->msg->len) {
413
-			if (pd->stop_after_dma) {
414
-				/* Simulate PIO end condition after DMA transfer */
415
-				i2c_op(pd, OP_RX_STOP, 0);
416
-				pd->pos++;
417
-				break;
418
-			}
419
-
420
-			if (real_pos < 0) {
421
-				i2c_op(pd, OP_RX_STOP, 0);
422
-				break;
423
-			}
424
-			data = i2c_op(pd, OP_RX_STOP_DATA, 0);
425
-		} else if (real_pos >= 0) {
426
-			data = i2c_op(pd, OP_RX, 0);
427
-		}
428
-
429
-		if (real_pos >= 0)
430
-			pd->msg->buf[real_pos] = data;
431
-	} while (0);
432
-
397
+ done:
433398 	pd->pos++;
434399 	return pd->pos == (pd->msg->len + 2);
435400 }
....@@ -467,7 +432,8 @@
467432 
468433 	if (wakeup) {
469434 		pd->sr |= SW_DONE;
470
-		wake_up(&pd->wait);
435
+		if (!pd->atomic_xfer)
436
+			wake_up(&pd->wait);
471437 	}
472438 
473439 	/* defeat write posting to avoid spurious WAIT interrupts */
....@@ -518,7 +484,7 @@
518484 	char *chan_name = dir == DMA_MEM_TO_DEV ? "tx" : "rx";
519485 	int ret;
520486 
521
-	chan = dma_request_slave_channel_reason(dev, chan_name);
487
+	chan = dma_request_chan(dev, chan_name);
522488 	if (IS_ERR(chan)) {
523489 		dev_dbg(dev, "request_channel failed for %s (%ld)\n", chan_name,
524490 			PTR_ERR(chan));
....@@ -619,6 +585,9 @@
619585 	pd->pos = -1;
620586 	pd->sr = 0;
621587 
588
+	if (pd->atomic_xfer)
589
+		return;
590
+
622591 	pd->dma_buf = i2c_get_dma_safe_msg_buf(pd->msg, 8);
623592 	if (pd->dma_buf)
624593 		sh_mobile_i2c_xfer_dma(pd);
....@@ -675,15 +644,13 @@
675644 	return i ? 0 : -ETIMEDOUT;
676645 }
677646 
678
-static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
679
-			      struct i2c_msg *msgs,
680
-			      int num)
647
+static int sh_mobile_xfer(struct sh_mobile_i2c_data *pd,
648
+			 struct i2c_msg *msgs, int num)
681649 {
682
-	struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
683650 	struct i2c_msg	*msg;
684651 	int err = 0;
685652 	int i;
686
-	long timeout;
653
+	long time_left;
687654 
688655 	/* Wake up device and enable clock */
689656 	pm_runtime_get_sync(pd->dev);
....@@ -698,17 +665,37 @@
698665 		start_ch(pd, msg, do_start);
699666 
700667 		if (do_start)
701
-			i2c_op(pd, OP_START, 0);
668
+			i2c_op(pd, OP_START);
702669 
703
-		/* The interrupt handler takes care of the rest... */
704
-		timeout = wait_event_timeout(pd->wait,
705
-				       pd->sr & (ICSR_TACK | SW_DONE),
706
-				       adapter->timeout);
670
+		if (pd->atomic_xfer) {
671
+			unsigned long j = jiffies + pd->adap.timeout;
707672 
708
-		/* 'stop_after_dma' tells if DMA transfer was complete */
709
-		i2c_put_dma_safe_msg_buf(pd->dma_buf, pd->msg, pd->stop_after_dma);
673
+			time_left = time_before_eq(jiffies, j);
674
+			while (time_left &&
675
+			       !(pd->sr & (ICSR_TACK | SW_DONE))) {
676
+				unsigned char sr = iic_rd(pd, ICSR);
710677 
711
-		if (!timeout) {
678
+				if (sr & (ICSR_AL   | ICSR_TACK |
679
+					  ICSR_WAIT | ICSR_DTE)) {
680
+					sh_mobile_i2c_isr(0, pd);
681
+					udelay(150);
682
+				} else {
683
+					cpu_relax();
684
+				}
685
+				time_left = time_before_eq(jiffies, j);
686
+			}
687
+		} else {
688
+			/* The interrupt handler takes care of the rest... */
689
+			time_left = wait_event_timeout(pd->wait,
690
+					pd->sr & (ICSR_TACK | SW_DONE),
691
+					pd->adap.timeout);
692
+
693
+			/* 'stop_after_dma' tells if DMA xfer was complete */
694
+			i2c_put_dma_safe_msg_buf(pd->dma_buf, pd->msg,
695
+						 pd->stop_after_dma);
696
+		}
697
+
698
+		if (!time_left) {
712699 			dev_err(pd->dev, "Transfer request timed out\n");
713700 			if (pd->dma_direction != DMA_NONE)
714701 				sh_mobile_i2c_cleanup_dma(pd);
....@@ -734,14 +721,35 @@
734721 	return err ?: num;
735722 }
736723 
724
+static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
725
+			      struct i2c_msg *msgs,
726
+			      int num)
727
+{
728
+	struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
729
+
730
+	pd->atomic_xfer = false;
731
+	return sh_mobile_xfer(pd, msgs, num);
732
+}
733
+
734
+static int sh_mobile_i2c_xfer_atomic(struct i2c_adapter *adapter,
735
+				     struct i2c_msg *msgs,
736
+				     int num)
737
+{
738
+	struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
739
+
740
+	pd->atomic_xfer = true;
741
+	return sh_mobile_xfer(pd, msgs, num);
742
+}
743
+
737744 static u32 sh_mobile_i2c_func(struct i2c_adapter *adapter)
738745 {
739746 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
740747 }
741748 
742749 static const struct i2c_algorithm sh_mobile_i2c_algorithm = {
743
-	.functionality	= sh_mobile_i2c_func,
744
-	.master_xfer	= sh_mobile_i2c_xfer,
750
+	.functionality = sh_mobile_i2c_func,
751
+	.master_xfer = sh_mobile_i2c_xfer,
752
+	.master_xfer_atomic = sh_mobile_i2c_xfer_atomic,
745753 };
746754 
747755 static const struct i2c_adapter_quirks sh_mobile_i2c_quirks = {
....@@ -749,8 +757,7 @@
749757 };
750758 
751759 /*
752
- * r8a7740 chip has lasting errata on I2C I/O pad reset.
753
- * this is work-around for it.
760
+ * r8a7740 has an errata regarding I2C I/O pad reset needing this workaround.
754761  */
755762 static int sh_mobile_i2c_r8a7740_workaround(struct sh_mobile_i2c_data *pd)
756763 {
....@@ -800,17 +807,17 @@
800807 static const struct of_device_id sh_mobile_i2c_dt_ids[] = {
801808 	{ .compatible = "renesas,iic-r8a73a4", .data = &fast_clock_dt_config },
802809 	{ .compatible = "renesas,iic-r8a7740", .data = &r8a7740_dt_config },
803
-	{ .compatible = "renesas,iic-r8a774c0", .data = &fast_clock_dt_config },
810
+	{ .compatible = "renesas,iic-r8a774c0", .data = &v2_freq_calc_dt_config },
804811 	{ .compatible = "renesas,iic-r8a7790", .data = &v2_freq_calc_dt_config },
805
-	{ .compatible = "renesas,iic-r8a7791", .data = &fast_clock_dt_config },
806
-	{ .compatible = "renesas,iic-r8a7792", .data = &fast_clock_dt_config },
807
-	{ .compatible = "renesas,iic-r8a7793", .data = &fast_clock_dt_config },
808
-	{ .compatible = "renesas,iic-r8a7794", .data = &fast_clock_dt_config },
809
-	{ .compatible = "renesas,rcar-gen2-iic", .data = &fast_clock_dt_config },
810
-	{ .compatible = "renesas,iic-r8a7795", .data = &fast_clock_dt_config },
811
-	{ .compatible = "renesas,rcar-gen3-iic", .data = &fast_clock_dt_config },
812
-	{ .compatible = "renesas,iic-r8a77990", .data = &fast_clock_dt_config },
812
+	{ .compatible = "renesas,iic-r8a7791", .data = &v2_freq_calc_dt_config },
813
+	{ .compatible = "renesas,iic-r8a7792", .data = &v2_freq_calc_dt_config },
814
+	{ .compatible = "renesas,iic-r8a7793", .data = &v2_freq_calc_dt_config },
815
+	{ .compatible = "renesas,iic-r8a7794", .data = &v2_freq_calc_dt_config },
816
+	{ .compatible = "renesas,iic-r8a7795", .data = &v2_freq_calc_dt_config },
817
+	{ .compatible = "renesas,iic-r8a77990", .data = &v2_freq_calc_dt_config },
813818 	{ .compatible = "renesas,iic-sh73a0", .data = &fast_clock_dt_config },
819
+	{ .compatible = "renesas,rcar-gen2-iic", .data = &v2_freq_calc_dt_config },
820
+	{ .compatible = "renesas,rcar-gen3-iic", .data = &v2_freq_calc_dt_config },
814821 	{ .compatible = "renesas,rmobile-iic", .data = &default_dt_config },
815822 	{},
816823 };
....@@ -884,7 +891,7 @@
884891 		return PTR_ERR(pd->reg);
885892 
886893 	ret = of_property_read_u32(dev->dev.of_node, "clock-frequency", &bus_speed);
887
-	pd->bus_speed = (ret || !bus_speed) ? STANDARD_MODE : bus_speed;
894
+	pd->bus_speed = (ret || !bus_speed) ? I2C_MAX_STANDARD_MODE_FREQ : bus_speed;
888895 	pd->clks_per_count = 1;
889896 
890897 	/* Newer variants come with two new bits in ICIC */
....@@ -949,27 +956,9 @@
949956 	return 0;
950957 }
951958 
952
-static int sh_mobile_i2c_runtime_nop(struct device *dev)
953
-{
954
-	/* Runtime PM callback shared between ->runtime_suspend()
955
-	 * and ->runtime_resume(). Simply returns success.
956
-	 *
957
-	 * This driver re-initializes all registers after
958
-	 * pm_runtime_get_sync() anyway so there is no need
959
-	 * to save and restore registers here.
960
-	 */
961
-	return 0;
962
-}
963
-
964
-static const struct dev_pm_ops sh_mobile_i2c_dev_pm_ops = {
965
-	.runtime_suspend = sh_mobile_i2c_runtime_nop,
966
-	.runtime_resume = sh_mobile_i2c_runtime_nop,
967
-};
968
-
969959 static struct platform_driver sh_mobile_i2c_driver = {
970960 	.driver		= {
971961 		.name		= "i2c-sh_mobile",
972
-		.pm		= &sh_mobile_i2c_dev_pm_ops,
973962 		.of_match_table = sh_mobile_i2c_dt_ids,
974963 	},
975964 	.probe		= sh_mobile_i2c_probe,
....@@ -989,6 +978,7 @@
989978 module_exit(sh_mobile_i2c_adap_exit);
990979 
991980 MODULE_DESCRIPTION("SuperH Mobile I2C Bus Controller driver");
992
-MODULE_AUTHOR("Magnus Damm and Wolfram Sang");
981
+MODULE_AUTHOR("Magnus Damm");
982
+MODULE_AUTHOR("Wolfram Sang");
993983 MODULE_LICENSE("GPL v2");
994984 MODULE_ALIAS("platform:i2c-sh_mobile");