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From:   Gwendal Grignou <gwendal@chromium.org>
To:     briannorris@chromium.org, jic23@kernel.org, knaack.h@gmx.de,
        lars@metafoo.de, pmeerw@pmeerw.net, lee.jones@linaro.org,
        bleung@chromium.org, enric.balletbo@collabora.com,
        dianders@chromium.org, groeck@chromium.org,
        fabien.lahoudere@collabora.com
Cc:     linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org,
        Gwendal Grignou <gwendal@chromium.org>
Subject: [PATCH v2 14/18] iio: cros_ec: Register to cros_ec_sensorhub when EC supports FIFO
Date:   Sun, 20 Oct 2019 22:53:59 -0700
Message-Id: <20191021055403.67849-15-gwendal@chromium.org>
In-Reply-To: <20191021055403.67849-1-gwendal@chromium.org>
References: <20191021055403.67849-1-gwendal@chromium.org>
MIME-Version: 1.0
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Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

When EC supports FIFO, each IIO device registers a callback, to put
samples in the buffer when they arrives from the FIFO.
We can still use a trigger to collect samples, but there may be some
duplications in the buffer: EC has a single FIFO, so once one sensor is
using it, all sensors event will be in the FIFO.
To be sure events generated by cros_ec_sensorhub or the trigger uses the
same time domain, current_timestamp_clock must be set to "boottime".

When no FIFO, the user space app needs to call trigger_new, or better
register a high precision timer.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
Change in v2 from "Use triggered buffer only when EC does not support
FIFO":
- Keep trigger all the time.
- Add  devm_add_action to cleanup callback registration.
- EC that "reports" legacy sensors do not have FIFO.
- Use iiio_is_buffer_enabled instead of checking the scan_mask
  before sending samples to buffer.
- Add empty lines for visibility.

 drivers/iio/accel/cros_ec_accel_legacy.c      |  8 +-
 .../cros_ec_sensors/cros_ec_lid_angle.c       |  2 +-
 .../common/cros_ec_sensors/cros_ec_sensors.c  |  8 +-
 .../cros_ec_sensors/cros_ec_sensors_core.c    | 80 ++++++++++++++++++-
 drivers/iio/light/cros_ec_light_prox.c        |  8 +-
 drivers/iio/pressure/cros_ec_baro.c           |  8 +-
 .../linux/iio/common/cros_ec_sensors_core.h   | 12 ++-
 7 files changed, 96 insertions(+), 30 deletions(-)

diff --git a/drivers/iio/accel/cros_ec_accel_legacy.c b/drivers/iio/accel/cros_ec_accel_legacy.c
index 65f85faf6f31d..66683df9fc433 100644
--- a/drivers/iio/accel/cros_ec_accel_legacy.c
+++ b/drivers/iio/accel/cros_ec_accel_legacy.c
@@ -171,7 +171,8 @@ static int cros_ec_accel_legacy_probe(struct platform_device *pdev)
 	if (!indio_dev)
 		return -ENOMEM;
 
-	ret = cros_ec_sensors_core_init(pdev, indio_dev, true);
+	ret = cros_ec_sensors_core_init(pdev, indio_dev, true,
+			cros_ec_sensors_capture, NULL);
 	if (ret)
 		return ret;
 
@@ -191,11 +192,6 @@ static int cros_ec_accel_legacy_probe(struct platform_device *pdev)
 		state->sign[CROS_EC_SENSOR_Z] = -1;
 	}
 
-	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
-			cros_ec_sensors_capture, NULL);
-	if (ret)
-		return ret;
-
 	return devm_iio_device_register(dev, indio_dev);
 }
 
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
index 1dcc2a16ab2dd..e30a59fcf0f95 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
@@ -97,7 +97,7 @@ static int cros_ec_lid_angle_probe(struct platform_device *pdev)
 	if (!indio_dev)
 		return -ENOMEM;
 
-	ret = cros_ec_sensors_core_init(pdev, indio_dev, false);
+	ret = cros_ec_sensors_core_init(pdev, indio_dev, false, NULL, NULL);
 	if (ret)
 		return ret;
 
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
index 7dce044734678..9e7903ff99f80 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
@@ -231,7 +231,8 @@ static int cros_ec_sensors_probe(struct platform_device *pdev)
 	if (!indio_dev)
 		return -ENOMEM;
 
-	ret = cros_ec_sensors_core_init(pdev, indio_dev, true);
+	ret = cros_ec_sensors_core_init(pdev, indio_dev, true,
+			cros_ec_sensors_capture, cros_ec_sensors_push_data);
 	if (ret)
 		return ret;
 
@@ -293,11 +294,6 @@ static int cros_ec_sensors_probe(struct platform_device *pdev)
 	else
 		state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
 
-	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
-			cros_ec_sensors_capture, NULL);
-	if (ret)
-		return ret;
-
 	return devm_iio_device_register(dev, indio_dev);
 }
 
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
index 4acb8b7310d43..3d2e17093c75a 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
@@ -12,6 +12,7 @@
 #include <linux/iio/iio.h>
 #include <linux/iio/kfifo_buf.h>
 #include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
 #include <linux/kernel.h>
 #include <linux/mfd/cros_ec.h>
 #include <linux/module.h>
@@ -83,17 +84,72 @@ static void get_default_min_max_freq(enum motionsensor_type type,
 	}
 }
 
+int cros_ec_sensors_push_data(
+		struct iio_dev *indio_dev,
+		s16 *data,
+		s64 timestamp)
+{
+	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
+	s16 *out;
+	unsigned int i;
+
+	/*
+	 * It can happen if we get a samples before the iio device is fully
+	 * registered.
+	 */
+	if (!st)
+		return 0;
+
+	/*
+	 * Ignore samples if the buffer is not set: it is needed if the ODR is
+	 * set but the buffer is not enabled yet.
+	 */
+	if (!iio_buffer_enabled(indio_dev))
+		return 0;
+
+	out = (s16 *)st->samples;
+	for_each_set_bit(i,
+			 indio_dev->active_scan_mask,
+			 indio_dev->masklength) {
+		*out = data[i];
+		out++;
+	}
+
+	iio_push_to_buffers_with_timestamp(indio_dev, st->samples, timestamp);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cros_ec_sensors_push_data);
+
+static void cros_ec_sensors_core_clean(void *arg)
+{
+	struct platform_device *pdev = (struct platform_device *)arg;
+	struct cros_ec_sensorhub *sensor_hub =
+		dev_get_drvdata(pdev->dev.parent);
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
+	u8 sensor_num = st->param.info.sensor_num;
+
+	cros_ec_sensorhub_unregister_push_data(sensor_hub, sensor_num);
+}
+
 /**
  * cros_ec_sensors_core_init() - basic initialization of the core structure
  * @pdev:		platform device created for the sensors
  * @indio_dev:		iio device structure of the device
  * @physical_device:	true if the device refers to a physical device
+ * @trigger_capture:    function pointer to call buffer is triggered,
+ *    for backward compatibility.
+ * @push_data:          function to call when cros_ec_sensorhub receives
+ *    a sample for that sensor.
  *
  * Return: 0 on success, -errno on failure.
  */
 int cros_ec_sensors_core_init(struct platform_device *pdev,
 			      struct iio_dev *indio_dev,
-			      bool physical_device)
+			      bool physical_device,
+			      cros_ec_sensors_capture_t trigger_capture,
+			      cros_ec_sensorhub_push_data_cb_t push_data)
 {
 	struct device *dev = &pdev->dev;
 	struct cros_ec_sensors_core_state *state = iio_priv(indio_dev);
@@ -132,8 +188,6 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
 	indio_dev->name = pdev->name;
 
 	if (physical_device) {
-		indio_dev->modes = INDIO_DIRECT_MODE;
-
 		state->param.cmd = MOTIONSENSE_CMD_INFO;
 		state->param.info.sensor_num = sensor_platform->sensor_num;
 		ret = cros_ec_motion_send_host_cmd(state, 0);
@@ -162,9 +216,27 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
 			state->frequencies[2] =
 			    state->resp->info_3.max_frequency;
 		}
+
+		ret = devm_iio_triggered_buffer_setup(
+				dev, indio_dev, NULL,
+				trigger_capture, NULL);
+		if (ret)
+			return ret;
+
+		if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
+			ret = cros_ec_sensorhub_register_push_data(
+					sensor_hub,
+					sensor_platform->sensor_num,
+					indio_dev, push_data);
+			if (ret)
+				return ret;
+
+			ret = devm_add_action_or_reset(
+					dev, cros_ec_sensors_core_clean, pdev);
+		}
 	}
 
-	return 0;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(cros_ec_sensors_core_init);
 
diff --git a/drivers/iio/light/cros_ec_light_prox.c b/drivers/iio/light/cros_ec_light_prox.c
index d85a391e50c59..da40c38370965 100644
--- a/drivers/iio/light/cros_ec_light_prox.c
+++ b/drivers/iio/light/cros_ec_light_prox.c
@@ -178,7 +178,8 @@ static int cros_ec_light_prox_probe(struct platform_device *pdev)
 	if (!indio_dev)
 		return -ENOMEM;
 
-	ret = cros_ec_sensors_core_init(pdev, indio_dev, true);
+	ret = cros_ec_sensors_core_init(pdev, indio_dev, true,
+			cros_ec_sensors_capture, cros_ec_sensors_push_data);
 	if (ret)
 		return ret;
 
@@ -237,11 +238,6 @@ static int cros_ec_light_prox_probe(struct platform_device *pdev)
 
 	state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
 
-	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
-					      cros_ec_sensors_capture, NULL);
-	if (ret)
-		return ret;
-
 	return devm_iio_device_register(dev, indio_dev);
 }
 
diff --git a/drivers/iio/pressure/cros_ec_baro.c b/drivers/iio/pressure/cros_ec_baro.c
index 2354302375dee..fb7daeb4b29f9 100644
--- a/drivers/iio/pressure/cros_ec_baro.c
+++ b/drivers/iio/pressure/cros_ec_baro.c
@@ -134,7 +134,8 @@ static int cros_ec_baro_probe(struct platform_device *pdev)
 	if (!indio_dev)
 		return -ENOMEM;
 
-	ret = cros_ec_sensors_core_init(pdev, indio_dev, true);
+	ret = cros_ec_sensors_core_init(pdev, indio_dev, true,
+			cros_ec_sensors_capture, cros_ec_sensors_push_data);
 	if (ret)
 		return ret;
 
@@ -180,11 +181,6 @@ static int cros_ec_baro_probe(struct platform_device *pdev)
 
 	state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
 
-	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
-					      cros_ec_sensors_capture, NULL);
-	if (ret)
-		return ret;
-
 	return devm_iio_device_register(dev, indio_dev);
 }
 
diff --git a/include/linux/iio/common/cros_ec_sensors_core.h b/include/linux/iio/common/cros_ec_sensors_core.h
index 0af918978f975..b4eb3790cde11 100644
--- a/include/linux/iio/common/cros_ec_sensors_core.h
+++ b/include/linux/iio/common/cros_ec_sensors_core.h
@@ -12,6 +12,7 @@
 #include <linux/irqreturn.h>
 #include <linux/platform_data/cros_ec_commands.h>
 #include <linux/platform_data/cros_ec_proto.h>
+#include <linux/platform_data/cros_ec_sensorhub.h>
 
 enum {
 	CROS_EC_SENSOR_X,
@@ -32,6 +33,9 @@ enum {
 /* Minimum sampling period to use when device is suspending */
 #define CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY 1000  /* 1 second */
 
+typedef irqreturn_t (*cros_ec_sensors_capture_t)(int irq, void *p);
+
+
 /**
  * struct cros_ec_sensors_core_state - state data for EC sensors IIO driver
  * @ec:				cros EC device structure
@@ -87,9 +91,15 @@ int cros_ec_sensors_read_cmd(struct iio_dev *indio_dev, unsigned long scan_mask,
 
 struct platform_device;
 int cros_ec_sensors_core_init(struct platform_device *pdev,
-			      struct iio_dev *indio_dev, bool physical_device);
+			      struct iio_dev *indio_dev, bool physical_device,
+			      cros_ec_sensors_capture_t trigger_capture,
+			      cros_ec_sensorhub_push_data_cb_t push_data);
 
 irqreturn_t cros_ec_sensors_capture(int irq, void *p);
+int cros_ec_sensors_push_data(
+		struct iio_dev *indio_dev,
+		s16 *data,
+		s64 timestamp);
 
 int cros_ec_motion_send_host_cmd(struct cros_ec_sensors_core_state *st,
 				 u16 opt_length);
-- 
2.23.0.866.gb869b98d4c-goog