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From:   cmo@melexis.com
To:     Jonathan Cameron <jic23@kernel.org>
Cc:     linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org,
        Andy Shevchenko <andy.shevchenko@gmail.com>,
        Crt Mori <cmo@melexis.com>
Subject: [PATCH v2 2/3] iio: temperature: mlx90632 Read sampling frequency
Date:   Sun,  4 Sep 2022 00:24:02 +0200
Message-Id: <20220903222402.3426058-1-cmo@melexis.com>
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Content-Transfer-Encoding: 8bit
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From: Crt Mori <cmo@melexis.com>

Allow users to read sensor sampling frequency to better plan the
application measurement requests.

Signed-off-by: Crt Mori <cmo@melexis.com>
---
 drivers/iio/temperature/mlx90632.c | 44 ++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/drivers/iio/temperature/mlx90632.c b/drivers/iio/temperature/mlx90632.c
index 9acd819c76a6..37edd324d6a1 100644
--- a/drivers/iio/temperature/mlx90632.c
+++ b/drivers/iio/temperature/mlx90632.c
@@ -80,6 +80,9 @@
 #define MLX90632_PWR_STATUS_CONTINUOUS MLX90632_PWR_STATUS(3) /* continuous */
 
 #define MLX90632_EE_RR(ee_val) (ee_val & GENMASK(10, 8)) /* Only Refresh Rate bits */
+#define MLX90632_REFRESH_RATE(ee_val) (MLX90632_EE_RR(ee_val) >> 8)
+					/* Extract Refresh Rate from ee register */
+#define MLX90632_REFRESH_RATE_STATUS(refresh_rate) (refresh_rate << 8)
 
 /* Measurement types */
 #define MLX90632_MTYP_MEDICAL 0
@@ -908,6 +911,24 @@ static int mlx90632_calc_ambient_dsp105(struct mlx90632_data *data, int *val)
 	return ret;
 }
 
+static int mlx90632_get_refresh_rate(struct mlx90632_data *data,
+				     int *refresh_rate)
+{
+	unsigned int meas1;
+	int ret;
+
+	ret = regmap_read(data->regmap, MLX90632_EE_MEDICAL_MEAS1, &meas1);
+	if (ret < 0)
+		return ret;
+
+	*refresh_rate = MLX90632_REFRESH_RATE(meas1);
+
+	return ret;
+}
+
+static const int mlx90632_freqs[][2] = { {0, 500000}, {1, 0}, {2, 0}, {4, 0},
+					  {8, 0}, {16, 0}, {32, 0}, {64, 0} };
+
 static int mlx90632_pm_interraction_wakeup(struct mlx90632_data *data)
 {
 	unsigned long now;
@@ -978,6 +999,15 @@ static int mlx90632_read_raw(struct iio_dev *indio_dev,
 		*val = data->object_ambient_temperature;
 		ret = IIO_VAL_INT;
 		break;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret = mlx90632_get_refresh_rate(data, &cr);
+		if (ret < 0)
+			goto mlx90632_read_raw_pm;
+
+		*val = mlx90632_freqs[cr][0];
+		*val2 = mlx90632_freqs[cr][1];
+		ret = IIO_VAL_INT_PLUS_MICRO;
+		break;
 	default:
 		ret = -EINVAL;
 		break;
@@ -1012,12 +1042,24 @@ static int mlx90632_write_raw(struct iio_dev *indio_dev,
 	}
 }
 
+static IIO_CONST_ATTR(sampling_frequency_available, "0.5 1 2 4 8 16 32 64");
+
+static struct attribute *mlx90632_attributes[] = {
+	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group mlx90632_attribute_group = {
+	.attrs = mlx90632_attributes,
+};
+
 static const struct iio_chan_spec mlx90632_channels[] = {
 	{
 		.type = IIO_TEMP,
 		.modified = 1,
 		.channel2 = IIO_MOD_TEMP_AMBIENT,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
 	},
 	{
 		.type = IIO_TEMP,
@@ -1025,12 +1067,14 @@ static const struct iio_chan_spec mlx90632_channels[] = {
 		.channel2 = IIO_MOD_TEMP_OBJECT,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
 			BIT(IIO_CHAN_INFO_CALIBEMISSIVITY) | BIT(IIO_CHAN_INFO_CALIBAMBIENT),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
 	},
 };
 
 static const struct iio_info mlx90632_info = {
 	.read_raw = mlx90632_read_raw,
 	.write_raw = mlx90632_write_raw,
+	.attrs = &mlx90632_attribute_group,
 };
 
 static int mlx90632_sleep(struct mlx90632_data *data)
-- 
2.34.1