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From:   Mehdi Djait <mehdi.djait.k@gmail.com>
To:     jic23@kernel.org, mazziesaccount@gmail.com
Cc:     krzysztof.kozlowski+dt@linaro.org,
        andriy.shevchenko@linux.intel.com, robh+dt@kernel.org,
        lars@metafoo.de, linux-iio@vger.kernel.org,
        linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
        Mehdi Djait <mehdi.djait.k@gmail.com>
Subject: [PATCH v3 6/7] iio: accel: kionix-kx022a: Add a function to retrieve number of bytes in buffer
Date:   Tue, 25 Apr 2023 00:22:26 +0200
Message-Id: <fc12d40f7c2132c1a9a1b5f83b79231dc8ce539f.1682373451.git.mehdi.djait.k@gmail.com>
In-Reply-To: <cover.1682373451.git.mehdi.djait.k@gmail.com>
References: <cover.1682373451.git.mehdi.djait.k@gmail.com>
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Since Kionix accelerometers use various numbers of bits to report data, a
device-specific function is required.
Implement the function as a callback in the device-specific chip_info structure

Signed-off-by: Mehdi Djait <mehdi.djait.k@gmail.com>
---
v3:
- fixed the warning of the kernel test robot in kx132_get_fifo_bytes
	(invalid assignment: &=, left side has type restricted __le16
	right side has type unsigned short)

v2:
- mentioned the kx132-1211 in the Kconfig
- added a kx132-specific get_fifo_bytes function
- changed the device name from "kx132" to "kx132-1211

 drivers/iio/accel/kionix-kx022a.c | 30 ++++++++++++++++++++----------
 drivers/iio/accel/kionix-kx022a.h |  4 ++++
 2 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/drivers/iio/accel/kionix-kx022a.c b/drivers/iio/accel/kionix-kx022a.c
index 66da3c8c3fd0..4a31d17c1f22 100644
--- a/drivers/iio/accel/kionix-kx022a.c
+++ b/drivers/iio/accel/kionix-kx022a.c
@@ -595,11 +595,28 @@ static int kx022a_drop_fifo_contents(struct kx022a_data *data)
 	return regmap_write(data->regmap, data->chip_info->buf_clear, 0x0);
 }
 
+static int kx022a_get_fifo_bytes(struct kx022a_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret, fifo_bytes;
+
+	ret = regmap_read(data->regmap, KX022A_REG_BUF_STATUS_1, &fifo_bytes);
+	if (ret) {
+		dev_err(dev, "Error reading buffer status\n");
+		return ret;
+	}
+
+	/* Let's not overflow if we for some reason get bogus value from i2c */
+	if (fifo_bytes == KX022A_FIFO_FULL_VALUE)
+		fifo_bytes = KX022A_FIFO_MAX_BYTES;
+
+	return fifo_bytes;
+}
+
 static int __kx022a_fifo_flush(struct iio_dev *idev, unsigned int samples,
 			       bool irq)
 {
 	struct kx022a_data *data = iio_priv(idev);
-	struct device *dev = regmap_get_device(data->regmap);
 	__le16 *buffer;
 	uint64_t sample_period;
 	int count, fifo_bytes;
@@ -611,15 +628,7 @@ static int __kx022a_fifo_flush(struct iio_dev *idev, unsigned int samples,
 	if (!buffer)
 		return -ENOMEM;
 
-	ret = regmap_read(data->regmap, KX022A_REG_BUF_STATUS_1, &fifo_bytes);
-	if (ret) {
-		dev_err(dev, "Error reading buffer status\n");
-		return ret;
-	}
-
-	/* Let's not overflow if we for some reason get bogus value from i2c */
-	if (fifo_bytes == KX022A_FIFO_FULL_VALUE)
-		fifo_bytes = KX022A_FIFO_MAX_BYTES;
+	fifo_bytes = data->chip_info->get_fifo_bytes(data);
 
 	if (fifo_bytes % KX022A_FIFO_SAMPLES_SIZE_BYTES)
 		dev_warn(data->dev, "Bad FIFO alignment. Data may be corrupt\n");
@@ -1023,6 +1032,7 @@ const struct kx022a_chip_info kx022a_chip_info = {
 	.inc5		  = KX022A_REG_INC5,
 	.inc6		  = KX022A_REG_INC6,
 	.xout_l		  = KX022A_REG_XOUT_L,
+	.get_fifo_bytes	  = kx022a_get_fifo_bytes,
 };
 EXPORT_SYMBOL_NS_GPL(kx022a_chip_info, IIO_KX022A);
 
diff --git a/drivers/iio/accel/kionix-kx022a.h b/drivers/iio/accel/kionix-kx022a.h
index 3c31e7d88f78..f043767067b7 100644
--- a/drivers/iio/accel/kionix-kx022a.h
+++ b/drivers/iio/accel/kionix-kx022a.h
@@ -76,6 +76,8 @@
 
 struct device;
 
+struct kx022a_data;
+
 /**
  * struct kx022a_chip_info - Kionix accelerometer chip specific information
  *
@@ -100,6 +102,7 @@ struct device;
  * @inc5:		interrupt control register 5
  * @inc6:		interrupt control register 6
  * @xout_l:		x-axis output least significant byte
+ * @get_fifo_bytes:	function pointer to get number of bytes in the FIFO buffer
  */
 struct kx022a_chip_info {
 	const char *name;
@@ -123,6 +126,7 @@ struct kx022a_chip_info {
 	u8 inc5;
 	u8 inc6;
 	u8 xout_l;
+	int (*get_fifo_bytes)(struct kx022a_data *);
 };
 
 int kx022a_probe_internal(struct device *dev, const struct kx022a_chip_info *chip_info);
-- 
2.30.2