forked from ~ljy/RK356X_SDK_RELEASE
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2023-12-11 072de836f53be56a70cecf70b43ae43b7ce17376 
 kernel/drivers/iio/magnetometer/ak8974.c
....@@ -1,3 +1,4 @@
1
+// SPDX-License-Identifier: GPL-2.0-only
12 /*
23  * Driver for the Asahi Kasei EMD Corporation AK8974
34  * and Aichi Steel AMI305 magnetometer chips.
....@@ -11,6 +12,7 @@
1112  * Author: Linus Walleij <linus.walleij@linaro.org>
1213  */
1314 #include <linux/module.h>
15
+#include <linux/mod_devicetable.h>
1416 #include <linux/kernel.h>
1517 #include <linux/i2c.h>
1618 #include <linux/interrupt.h>
....@@ -48,6 +50,7 @@
4850 #define AK8974_WHOAMI_VALUE_AMI306 0x46
4951 #define AK8974_WHOAMI_VALUE_AMI305 0x47
5052 #define AK8974_WHOAMI_VALUE_AK8974 0x48
53
+#define AK8974_WHOAMI_VALUE_HSCDTD008A 0x49
5154 
5255 #define AK8974_DATA_X		0x10
5356 #define AK8974_DATA_Y		0x12
....@@ -139,6 +142,12 @@
139142 #define AK8974_INT_CTRL_PULSE	BIT(1) /* 0 = latched; 1 = pulse (50 usec) */
140143 #define AK8974_INT_CTRL_RESDEF	(AK8974_INT_CTRL_XYZEN | AK8974_INT_CTRL_POL)
141144 
145
+/* HSCDTD008A-specific control register */
146
+#define HSCDTD008A_CTRL4	0x1E
147
+#define HSCDTD008A_CTRL4_MMD	BIT(7)	/* must be set to 1 */
148
+#define HSCDTD008A_CTRL4_RANGE	BIT(4)	/* 0 = 14-bit output; 1 = 15-bit output */
149
+#define HSCDTD008A_CTRL4_RESDEF	(HSCDTD008A_CTRL4_MMD | HSCDTD008A_CTRL4_RANGE)
150
+
142151 /* The AMI305 has elaborate FW version and serial number registers */
143152 #define AMI305_VER		0xE8
144153 #define AMI305_SN		0xEA
....@@ -172,6 +181,7 @@
172181  * @drdy_irq: uses the DRDY IRQ line
173182  * @drdy_complete: completion for DRDY
174183  * @drdy_active_low: the DRDY IRQ is active low
184
+ * @scan: timestamps
175185  */
176186 struct ak8974 {
177187 	struct i2c_client *i2c;
....@@ -245,10 +255,17 @@
245255 	ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF);
246256 	if (ret)
247257 		return ret;
248
-	ret = regmap_write(ak8974->map, AK8974_INT_CTRL,
249
-			   AK8974_INT_CTRL_RESDEF);
250
-	if (ret)
251
-		return ret;
258
+	if (ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A) {
259
+		ret = regmap_write(ak8974->map, AK8974_INT_CTRL,
260
+				   AK8974_INT_CTRL_RESDEF);
261
+		if (ret)
262
+			return ret;
263
+	} else {
264
+		ret = regmap_write(ak8974->map, HSCDTD008A_CTRL4,
265
+				   HSCDTD008A_CTRL4_RESDEF);
266
+		if (ret)
267
+			return ret;
268
+	}
252269 
253270 	/* After reset, power off is default state */
254271 	return ak8974_set_power(ak8974, AK8974_PWR_OFF);
....@@ -271,6 +288,8 @@
271288 		if (ret)
272289 			return ret;
273290 	}
291
+	if (ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A)
292
+		return 0;
274293 	ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL);
275294 	if (ret)
276295 		return ret;
....@@ -481,7 +500,7 @@
481500 	switch (whoami) {
482501 	case AK8974_WHOAMI_VALUE_AMI306:
483502 		name = "ami306";
484
-		/* fall-through */
503
+		fallthrough;
485504 	case AK8974_WHOAMI_VALUE_AMI305:
486505 		ret = regmap_read(ak8974->map, AMI305_VER, &fw);
487506 		if (ret)
....@@ -498,6 +517,10 @@
498517 	case AK8974_WHOAMI_VALUE_AK8974:
499518 		name = "ak8974";
500519 		dev_info(&ak8974->i2c->dev, "detected AK8974\n");
520
+		break;
521
+	case AK8974_WHOAMI_VALUE_HSCDTD008A:
522
+		name = "hscdtd008a";
523
+		dev_info(&ak8974->i2c->dev, "detected hscdtd008a\n");
501524 		break;
502525 	default:
503526 		dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ",
....@@ -538,47 +561,103 @@
538561 	return 0;
539562 }
540563 
564
+static int ak8974_measure_channel(struct ak8974 *ak8974, unsigned long address,
565
+				  int *val)
566
+{
567
+	__le16 hw_values[3];
568
+	int ret;
569
+
570
+	pm_runtime_get_sync(&ak8974->i2c->dev);
571
+	mutex_lock(&ak8974->lock);
572
+
573
+	/*
574
+	 * We read all axes and discard all but one, for optimized
575
+	 * reading, use the triggered buffer.
576
+	 */
577
+	ret = ak8974_trigmeas(ak8974);
578
+	if (ret)
579
+		goto out_unlock;
580
+	ret = ak8974_getresult(ak8974, hw_values);
581
+	if (ret)
582
+		goto out_unlock;
583
+	/*
584
+	 * This explicit cast to (s16) is necessary as the measurement
585
+	 * is done in 2's complement with positive and negative values.
586
+	 * The follwing assignment to *val will then convert the signed
587
+	 * s16 value to a signed int value.
588
+	 */
589
+	*val = (s16)le16_to_cpu(hw_values[address]);
590
+out_unlock:
591
+	mutex_unlock(&ak8974->lock);
592
+	pm_runtime_mark_last_busy(&ak8974->i2c->dev);
593
+	pm_runtime_put_autosuspend(&ak8974->i2c->dev);
594
+
595
+	return ret;
596
+}
597
+
541598 static int ak8974_read_raw(struct iio_dev *indio_dev,
542599 			   struct iio_chan_spec const *chan,
543600 			   int *val, int *val2,
544601 			   long mask)
545602 {
546603 	struct ak8974 *ak8974 = iio_priv(indio_dev);
547
-	__le16 hw_values[3];
548
-	int ret = -EINVAL;
549
-
550
-	pm_runtime_get_sync(&ak8974->i2c->dev);
551
-	mutex_lock(&ak8974->lock);
604
+	int ret;
552605 
553606 	switch (mask) {
554607 	case IIO_CHAN_INFO_RAW:
555608 		if (chan->address > 2) {
556609 			dev_err(&ak8974->i2c->dev, "faulty channel address\n");
557
-			ret = -EIO;
558
-			goto out_unlock;
610
+			return -EIO;
559611 		}
560
-		ret = ak8974_trigmeas(ak8974);
612
+		ret = ak8974_measure_channel(ak8974, chan->address, val);
561613 		if (ret)
562
-			goto out_unlock;
563
-		ret = ak8974_getresult(ak8974, hw_values);
564
-		if (ret)
565
-			goto out_unlock;
566
-
567
-		/*
568
-		 * We read all axes and discard all but one, for optimized
569
-		 * reading, use the triggered buffer.
570
-		 */
571
-		*val = (s16)le16_to_cpu(hw_values[chan->address]);
572
-
573
-		ret = IIO_VAL_INT;
614
+			return ret;
615
+		return IIO_VAL_INT;
616
+	case IIO_CHAN_INFO_SCALE:
617
+		switch (ak8974->variant) {
618
+		case AK8974_WHOAMI_VALUE_AMI306:
619
+		case AK8974_WHOAMI_VALUE_AMI305:
620
+			/*
621
+			 * The datasheet for AMI305 and AMI306, page 6
622
+			 * specifies the range of the sensor to be
623
+			 * +/- 12 Gauss.
624
+			 */
625
+			*val = 12;
626
+			/*
627
+			 * 12 bits are used, +/- 2^11
628
+			 * [ -2048 .. 2047 ] (manual page 20)
629
+			 * [ 0xf800 .. 0x07ff ]
630
+			 */
631
+			*val2 = 11;
632
+			return IIO_VAL_FRACTIONAL_LOG2;
633
+		case AK8974_WHOAMI_VALUE_HSCDTD008A:
634
+			/*
635
+			 * The datasheet for HSCDTF008A, page 3 specifies the
636
+			 * range of the sensor as +/- 2.4 mT per axis, which
637
+			 * corresponds to +/- 2400 uT = +/- 24 Gauss.
638
+			 */
639
+			*val = 24;
640
+			/*
641
+			 * 15 bits are used (set up in CTRL4), +/- 2^14
642
+			 * [ -16384 .. 16383 ] (manual page 24)
643
+			 * [ 0xc000 .. 0x3fff ]
644
+			 */
645
+			*val2 = 14;
646
+			return IIO_VAL_FRACTIONAL_LOG2;
647
+		default:
648
+			/* GUESSING +/- 12 Gauss */
649
+			*val = 12;
650
+			/* GUESSING 12 bits ADC +/- 2^11 */
651
+			*val2 = 11;
652
+			return IIO_VAL_FRACTIONAL_LOG2;
653
+		}
654
+		break;
655
+	default:
656
+		/* Unknown request */
657
+		break;
574658 	}
575659 
576
- out_unlock:
577
-	mutex_unlock(&ak8974->lock);
578
-	pm_runtime_mark_last_busy(&ak8974->i2c->dev);
579
-	pm_runtime_put_autosuspend(&ak8974->i2c->dev);
580
-
581
-	return ret;
660
+	return -EINVAL;
582661 }
583662 
584663 static void ak8974_fill_buffer(struct iio_dev *indio_dev)
....@@ -634,27 +713,44 @@
634713 	{ },
635714 };
636715 
637
-#define AK8974_AXIS_CHANNEL(axis, index)				\
716
+#define AK8974_AXIS_CHANNEL(axis, index, bits)				\
638717 	{								\
639718 		.type = IIO_MAGN,					\
640719 		.modified = 1,						\
641720 		.channel2 = IIO_MOD_##axis,				\
642
-		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
721
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
722
+			BIT(IIO_CHAN_INFO_SCALE),			\
643723 		.ext_info = ak8974_ext_info,				\
644724 		.address = index,					\
645725 		.scan_index = index,					\
646726 		.scan_type = {						\
647727 			.sign = 's',					\
648
-			.realbits = 16,					\
728
+			.realbits = bits,				\
649729 			.storagebits = 16,				\
650730 			.endianness = IIO_LE				\
651731 		},							\
652732 	}
653733 
654
-static const struct iio_chan_spec ak8974_channels[] = {
655
-	AK8974_AXIS_CHANNEL(X, 0),
656
-	AK8974_AXIS_CHANNEL(Y, 1),
657
-	AK8974_AXIS_CHANNEL(Z, 2),
734
+/*
735
+ * We have no datasheet for the AK8974 but we guess that its
736
+ * ADC is 12 bits. The AMI305 and AMI306 certainly has 12bit
737
+ * ADC.
738
+ */
739
+static const struct iio_chan_spec ak8974_12_bits_channels[] = {
740
+	AK8974_AXIS_CHANNEL(X, 0, 12),
741
+	AK8974_AXIS_CHANNEL(Y, 1, 12),
742
+	AK8974_AXIS_CHANNEL(Z, 2, 12),
743
+	IIO_CHAN_SOFT_TIMESTAMP(3),
744
+};
745
+
746
+/*
747
+ * The HSCDTD008A has 15 bits resolution the way we set it up
748
+ * in CTRL4.
749
+ */
750
+static const struct iio_chan_spec ak8974_15_bits_channels[] = {
751
+	AK8974_AXIS_CHANNEL(X, 0, 15),
752
+	AK8974_AXIS_CHANNEL(Y, 1, 15),
753
+	AK8974_AXIS_CHANNEL(Z, 2, 15),
658754 	IIO_CHAN_SOFT_TIMESTAMP(3),
659755 };
660756 
....@@ -677,18 +773,18 @@
677773 	case AK8974_INT_CTRL:
678774 	case AK8974_INT_THRES:
679775 	case AK8974_INT_THRES + 1:
776
+		return true;
680777 	case AK8974_PRESET:
681778 	case AK8974_PRESET + 1:
682
-		return true;
779
+		return ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A;
683780 	case AK8974_OFFSET_X:
684781 	case AK8974_OFFSET_X + 1:
685782 	case AK8974_OFFSET_Y:
686783 	case AK8974_OFFSET_Y + 1:
687784 	case AK8974_OFFSET_Z:
688785 	case AK8974_OFFSET_Z + 1:
689
-		if (ak8974->variant == AK8974_WHOAMI_VALUE_AK8974)
690
-			return true;
691
-		return false;
786
+		return ak8974->variant == AK8974_WHOAMI_VALUE_AK8974 ||
787
+		       ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A;
692788 	case AMI305_OFFSET_X:
693789 	case AMI305_OFFSET_X + 1:
694790 	case AMI305_OFFSET_Y:
....@@ -737,9 +833,8 @@
737833 	ak8974->i2c = i2c;
738834 	mutex_init(&ak8974->lock);
739835 
740
-	ret = of_iio_read_mount_matrix(&i2c->dev,
741
-				       "mount-matrix",
742
-				       &ak8974->orientation);
836
+	ret = iio_read_mount_matrix(&i2c->dev, "mount-matrix",
837
+				    &ak8974->orientation);
743838 	if (ret)
744839 		return ret;
745840 
....@@ -749,10 +844,8 @@
749844 	ret = devm_regulator_bulk_get(&i2c->dev,
750845 				      ARRAY_SIZE(ak8974->regs),
751846 				      ak8974->regs);
752
-	if (ret < 0) {
753
-		dev_err(&i2c->dev, "cannot get regulators\n");
754
-		return ret;
755
-	}
847
+	if (ret < 0)
848
+		return dev_err_probe(&i2c->dev, ret, "cannot get regulators\n");
756849 
757850 	ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
758851 	if (ret < 0) {
....@@ -795,9 +888,21 @@
795888 		goto disable_pm;
796889 	}
797890 
798
-	indio_dev->dev.parent = &i2c->dev;
799
-	indio_dev->channels = ak8974_channels;
800
-	indio_dev->num_channels = ARRAY_SIZE(ak8974_channels);
891
+	switch (ak8974->variant) {
892
+	case AK8974_WHOAMI_VALUE_AMI306:
893
+	case AK8974_WHOAMI_VALUE_AMI305:
894
+		indio_dev->channels = ak8974_12_bits_channels;
895
+		indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels);
896
+		break;
897
+	case AK8974_WHOAMI_VALUE_HSCDTD008A:
898
+		indio_dev->channels = ak8974_15_bits_channels;
899
+		indio_dev->num_channels = ARRAY_SIZE(ak8974_15_bits_channels);
900
+		break;
901
+	default:
902
+		indio_dev->channels = ak8974_12_bits_channels;
903
+		indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels);
904
+		break;
905
+	}
801906 	indio_dev->info = &ak8974_info;
802907 	indio_dev->available_scan_masks = ak8974_scan_masks;
803908 	indio_dev->modes = INDIO_DIRECT_MODE;
....@@ -931,12 +1036,14 @@
9311036 	{"ami305", 0 },
9321037 	{"ami306", 0 },
9331038 	{"ak8974", 0 },
1039
+	{"hscdtd008a", 0 },
9341040 	{}
9351041 };
9361042 MODULE_DEVICE_TABLE(i2c, ak8974_id);
9371043 
9381044 static const struct of_device_id ak8974_of_match[] = {
9391045 	{ .compatible = "asahi-kasei,ak8974", },
1046
+	{ .compatible = "alps,hscdtd008a", },
9401047 	{}
9411048 };
9421049 MODULE_DEVICE_TABLE(of, ak8974_of_match);
....@@ -945,7 +1052,7 @@
9451052 	.driver	 = {
9461053 		.name	= "ak8974",
9471054 		.pm = &ak8974_dev_pm_ops,
948
-		.of_match_table = of_match_ptr(ak8974_of_match),
1055
+		.of_match_table = ak8974_of_match,
9491056 	},
9501057 	.probe	  = ak8974_probe,
9511058 	.remove	  = ak8974_remove,