[PATCH v8 0/3] media: pci: intel: ivsc: Add driver of Intel Visual Sensing Controller(IVSC)

[PATCH v8 0/3] media: pci: intel: ivsc: Add driver of Intel Visual Sensing Controller(IVSC)

[Wentong Wu]

Intel Visual Sensing Controller (IVSC), codenamed "Clover Falls", is a
companion chip designed to provide secure and low power vision capability
to IA platforms. IVSC is available in existing commercial platforms from
multiple OEMs.

The primary use case of IVSC is to bring in context awareness. IVSC
interfaces directly with the platform main camera sensor via a CSI-2 link
and processes the image data with the embedded AI engine. The detected
events are sent over I2C to ISH (Intel Sensor Hub) for additional data
fusion from multiple sensors. The fusion results are used to implement
advanced use cases like:
 - Face detection to unlock screen
 - Detect user presence to manage backlight setting or waking up system

Since the Image Processing Unit(IPU) used on the host processor needs to
configure the CSI-2 link in normal camera usages, the CSI-2 link and
camera sensor can only be used in mutually-exclusive ways by host IPU and
IVSC. By default the IVSC owns the CSI-2 link and camera sensor. The IPU
driver can take ownership of the CSI-2 link and camera sensor using the
interfaces exported via v4l2 sub-device.

Switching ownership requires an interface with two different hardware
modules inside IVSC. The software interface to these modules is via Intel
MEI (The Intel Management Engine) commands. These two hardware modules
have two different MEI UUIDs to enumerate. These hardware modules are:
 - ACE (Algorithm Context Engine): This module is for algorithm computing
when IVSC owns camera sensor. Also ACE module controls camera sensor's
ownership. This hardware module is used to set ownership of camera sensor.
 - CSI (Camera Serial Interface): This module is used to route camera
sensor data either to IVSC or to host for IPU driver and application.

IVSC also provides a privacy mode. When privacy mode is turned on, camera
sensor can't be used. This means that both ACE and host IPU can't get
image data. And when this mode is turned on, users are informed via v4l2
control API.

In summary, to acquire ownership of camera by IPU driver, first ACE
module needs to be informed of ownership and then to setup MIPI CSI-2
link for the camera sensor and IPU.

Implementation:
There are two different drivers to handle ACE and CSI hardware modules
inside IVSC.
 - ivsc_csi: MEI client driver to send commands and receive notifications
from CSI module.
 - ivsc_ace: MEI client driver to send commands and get status from ACE
module.
Interface is exposed via v4l2 sub-devcie APIs to acquire and release
camera sensor and CSI-2 link.

Below diagram shows connections of IVSC/ISH/IPU/Camera sensor.
-----------------------------------------------------------------------------
| Host Processor                                                            |
|                                                                           |
|       -----------------       -----------------       ---------------     |
|       |               |       |               |       |             | I2C |
|       |      IPU      |       |      ISH      |       |camera driver|--|  |
|       |               |       |               |       |             |  |  |
|       -----------------       -----------------       ---------------  |  |
|               |                       |                      |         |  |
|               |                       |               ---------------  |  |
|               |                       |               |             |  |  |
|               |                       |               | IVSC driver |  |  |
|               |                       |               |             |  |  |
|               |                       |               ---------------  |  |
|               |                       |                      |         |  |
----------------|-----------------------|----------------------|---------|---
                | CSI                   | I2C                  |SPI      |
                |                       |                      |         |
----------------|-----------------------|----------------      |         |
| IVSC          |                                       |      |         |
|               |                                       |      |         |
|       -----------------       -----------------       |      |         |
|       |               |       |               |       |      |         |
|       |      CSI      |       |      ACE      |       |------|         |
|       |               |       |               |       |                |
|       -----------------       -----------------       |                |
|               |                       | I2C           |                |
----------------|-----------------------|----------------                |
                | CSI                   |                                |
                |                       |                                |
            --------------------------------                             |
            |                              | I2C                         |
            |         camera sensor        |-----------------------------|
            |                              |
            --------------------------------

---
v8:
 - use new uuid structure and macro

v7:
 - add more comments for IVSC ACPI dev

v6:
 - add V4L2_SUBDEV_FL_HAS_EVENTS flag for csi subdev
 - add the LINK FREQUENCY volatile control
 - query sensor link frequency with v4l2_get_link_freq api
 - add error handling for creating device link
 - fix coding style issues

v5:
 - probe mei_csi only after software node has been setup

v4:
 - call v4l2_ctrl_handler_free() if setting up the handler failed
 - set V4L2_CTRL_FLAG_READ_ONLY for privacy_ctrl
 - add dev_warn if failed to switch CSI-2 link to IVSC
 - use v4l2_fwnode_endpoint_alloc_parse to get num_data_lanes
 - add document about how sensor connected to IVSC is powered
 - move lock to mei_ace_send
 - check return value for device_link_add

Wentong Wu (3):
  media: pci: intel: ivsc: Add CSI submodule
  media: pci: intel: ivsc: Add ACE submodule
  ACPI: delay enumeration of devices with a _DEP pointing to IVSC device

 drivers/acpi/scan.c                    |   2 +
 drivers/media/pci/Kconfig              |   1 +
 drivers/media/pci/intel/Makefile       |   2 +
 drivers/media/pci/intel/ivsc/Kconfig   |  12 +
 drivers/media/pci/intel/ivsc/Makefile  |   9 +
 drivers/media/pci/intel/ivsc/mei_ace.c | 591 ++++++++++++++++++++++++
 drivers/media/pci/intel/ivsc/mei_csi.c | 809 +++++++++++++++++++++++++++++++++
 7 files changed, 1426 insertions(+)
 create mode 100644 drivers/media/pci/intel/ivsc/Kconfig
 create mode 100644 drivers/media/pci/intel/ivsc/Makefile
 create mode 100644 drivers/media/pci/intel/ivsc/mei_ace.c
 create mode 100644 drivers/media/pci/intel/ivsc/mei_csi.c

-- 
2.7.4

[PATCH v8 1/3] media: pci: intel: ivsc: Add CSI submodule

[Wentong Wu]

CSI is a submodule of IVSC which can route camera sensor data
to the outbound MIPI CSI-2 interface.

The interface communicating with firmware is via MEI. There is
a separate MEI UUID, which this driver uses to enumerate.

To route camera sensor data to host, the information of link
frequency and number of data lanes is sent to firmware by
sending MEI command when starting stream.

CSI also provides a privacy mode. When privacy mode is turned
on, camera sensor can't be used. This means that both IVSC and
host Image Processing Unit(IPU) can't get image data. And when
this mode is turned on, user is notified via v4l2 control
callback.

Signed-off-by: Wentong Wu <wentong.wu@intel.com>
---
 drivers/media/pci/Kconfig              |   1 +
 drivers/media/pci/intel/Makefile       |   2 +
 drivers/media/pci/intel/ivsc/Kconfig   |  12 +
 drivers/media/pci/intel/ivsc/Makefile  |   6 +
 drivers/media/pci/intel/ivsc/mei_csi.c | 809 +++++++++++++++++++++++++++++++++
 5 files changed, 830 insertions(+)
 create mode 100644 drivers/media/pci/intel/ivsc/Kconfig
 create mode 100644 drivers/media/pci/intel/ivsc/Makefile
 create mode 100644 drivers/media/pci/intel/ivsc/mei_csi.c

diff --git a/drivers/media/pci/Kconfig b/drivers/media/pci/Kconfig
index dff0b45..c157f7c 100644
--- a/drivers/media/pci/Kconfig
+++ b/drivers/media/pci/Kconfig
@@ -72,6 +72,7 @@ config VIDEO_PCI_SKELETON
 	  when developing new drivers.
 
 source "drivers/media/pci/intel/ipu3/Kconfig"
+source "drivers/media/pci/intel/ivsc/Kconfig"
 
 endif #MEDIA_PCI_SUPPORT
 endif #PCI
diff --git a/drivers/media/pci/intel/Makefile b/drivers/media/pci/intel/Makefile
index 0b4236c..d27ca63 100644
--- a/drivers/media/pci/intel/Makefile
+++ b/drivers/media/pci/intel/Makefile
@@ -4,3 +4,5 @@
 #
 
 obj-y	+= ipu3/
+
+obj-$(CONFIG_INTEL_VSC) += ivsc/
diff --git a/drivers/media/pci/intel/ivsc/Kconfig b/drivers/media/pci/intel/ivsc/Kconfig
new file mode 100644
index 0000000..9535ac1
--- /dev/null
+++ b/drivers/media/pci/intel/ivsc/Kconfig
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# Copyright (C) 2023, Intel Corporation. All rights reserved.
+
+config INTEL_VSC
+	tristate "Intel Visual Sensing Controller"
+	depends on INTEL_MEI
+	help
+	  This adds support for Intel Visual Sensing Controller (IVSC).
+
+	  Enables the IVSC firmware services required for controlling
+	  camera sensor ownership and CSI-2 link through Image Processing
+	  Unit(IPU) driver of Intel.
diff --git a/drivers/media/pci/intel/ivsc/Makefile b/drivers/media/pci/intel/ivsc/Makefile
new file mode 100644
index 0000000..cbd194a
--- /dev/null
+++ b/drivers/media/pci/intel/ivsc/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Copyright (C) 2023, Intel Corporation. All rights reserved.
+
+obj-$(CONFIG_INTEL_VSC) += ivsc-csi.o
+ivsc-csi-y += mei_csi.o
diff --git a/drivers/media/pci/intel/ivsc/mei_csi.c b/drivers/media/pci/intel/ivsc/mei_csi.c
new file mode 100644
index 0000000..6667dde
--- /dev/null
+++ b/drivers/media/pci/intel/ivsc/mei_csi.c
@@ -0,0 +1,809 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023 Intel Corporation. All rights reserved.
+ * Intel Visual Sensing Controller CSI Linux driver
+ */
+
+/*
+ * To set ownership of CSI-2 link and to configure CSI-2 link, there
+ * are specific commands, which are sent via MEI protocol. The send
+ * command function uses "completion" as a synchronization mechanism.
+ * The response for command is received via a mei callback which wakes
+ * up the caller. There can be only one outstanding command at a time.
+ */
+
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/math64.h>
+#include <linux/mei_cl_bus.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/units.h>
+#include <linux/uuid.h>
+#include <linux/workqueue.h>
+
+#include <media/v4l2-async.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-subdev.h>
+
+#define MEI_CSI_DRIVER_NAME "ivsc_csi"
+
+/* the 5s used here is based on experiment */
+#define CSI_CMD_TIMEOUT (5 * HZ)
+/* to setup CSI-2 link an extra delay needed and determined experimentally */
+#define CSI_FW_READY_DELAY_MS 100
+/* link frequency unit is 100kHz */
+#define CSI_LINK_FREQ(x) ((u32)(div_u64(x, 100 * HZ_PER_KHZ)))
+
+/*
+ * identify the command id supported by firmware
+ * IPC, as well as the privacy notification id
+ * used when processing privacy event.
+ */
+enum csi_cmd_id {
+	/* used to set csi ownership */
+	CSI_SET_OWNER = 0,
+
+	/* used to configure CSI-2 link */
+	CSI_SET_CONF = 2,
+
+	/* privacy notification id used when privacy state changes */
+	CSI_PRIVACY_NOTIF = 6,
+};
+
+/* CSI-2 link ownership definition */
+enum csi_link_owner {
+	CSI_LINK_IVSC,
+	CSI_LINK_HOST,
+};
+
+/* privacy status definition */
+enum ivsc_privacy_status {
+	CSI_PRIVACY_OFF,
+	CSI_PRIVACY_ON,
+	CSI_PRIVACY_MAX,
+};
+
+enum csi_pads {
+	CSI_PAD_SOURCE,
+	CSI_PAD_SINK,
+	CSI_NUM_PADS
+};
+
+/* configuration of the CSI-2 link between host and IVSC */
+struct csi_link_cfg {
+	/* number of data lanes used on the CSI-2 link */
+	u32 nr_of_lanes;
+
+	/* frequency of the CSI-2 link */
+	u32 link_freq;
+
+	/* for future use */
+	u32 rsvd[2];
+} __packed;
+
+/* CSI command structure */
+struct csi_cmd {
+	u32 cmd_id;
+	union _cmd_param {
+		u32 param;
+		struct csi_link_cfg conf;
+	} param;
+} __packed;
+
+/* CSI notification structure */
+struct csi_notif {
+	u32 cmd_id;
+	int status;
+	union _resp_cont {
+		u32 cont;
+		struct csi_link_cfg conf;
+	} cont;
+} __packed;
+
+struct mei_csi {
+	struct mei_cl_device *cldev;
+
+	/* command response */
+	struct csi_notif cmd_response;
+	/* used to wait for command response from firmware */
+	struct completion cmd_completion;
+	/* protect command download */
+	struct mutex lock;
+
+	struct v4l2_subdev subdev;
+	struct v4l2_subdev *remote;
+	struct v4l2_async_notifier notifier;
+	struct v4l2_ctrl_handler ctrl_handler;
+	struct v4l2_ctrl *freq_ctrl;
+	struct v4l2_ctrl *privacy_ctrl;
+	unsigned int remote_pad;
+	/* start streaming or not */
+	int streaming;
+
+	struct media_pad pads[CSI_NUM_PADS];
+	struct v4l2_mbus_framefmt format_mbus[CSI_NUM_PADS];
+
+	/* number of data lanes used on the CSI-2 link */
+	u32 nr_of_lanes;
+	/* frequency of the CSI-2 link */
+	u64 link_freq;
+
+	/* privacy status */
+	enum ivsc_privacy_status status;
+};
+
+static const struct v4l2_mbus_framefmt mei_csi_format_mbus_default = {
+	.width = 1,
+	.height = 1,
+	.code = MEDIA_BUS_FMT_Y8_1X8,
+	.field = V4L2_FIELD_NONE,
+};
+
+static inline struct mei_csi *notifier_to_csi(struct v4l2_async_notifier *n)
+{
+	return container_of(n, struct mei_csi, notifier);
+}
+
+static inline struct mei_csi *sd_to_csi(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct mei_csi, subdev);
+}
+
+static inline struct mei_csi *ctrl_to_csi(struct v4l2_ctrl *ctrl)
+{
+	return container_of(ctrl->handler, struct mei_csi, ctrl_handler);
+}
+
+/* send a command to firmware and mutex must be held by caller */
+static int mei_csi_send(struct mei_csi *csi, u8 *buf, size_t len)
+{
+	struct csi_cmd *cmd = (struct csi_cmd *)buf;
+	int ret;
+
+	reinit_completion(&csi->cmd_completion);
+
+	ret = mei_cldev_send(csi->cldev, buf, len);
+	if (ret < 0)
+		goto out;
+
+	ret = wait_for_completion_killable_timeout(&csi->cmd_completion,
+						   CSI_CMD_TIMEOUT);
+	if (ret < 0) {
+		goto out;
+	} else if (!ret) {
+		ret = -ETIMEDOUT;
+		goto out;
+	}
+
+	/* command response status */
+	ret = csi->cmd_response.status;
+	if (ret) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (csi->cmd_response.cmd_id != cmd->cmd_id)
+		ret = -EINVAL;
+
+out:
+	return ret;
+}
+
+/* set CSI-2 link ownership */
+static int csi_set_link_owner(struct mei_csi *csi, enum csi_link_owner owner)
+{
+	struct csi_cmd cmd = { 0 };
+	size_t cmd_size;
+	int ret;
+
+	cmd.cmd_id = CSI_SET_OWNER;
+	cmd.param.param = owner;
+	cmd_size = sizeof(cmd.cmd_id) + sizeof(cmd.param.param);
+
+	mutex_lock(&csi->lock);
+
+	ret = mei_csi_send(csi, (u8 *)&cmd, cmd_size);
+
+	mutex_unlock(&csi->lock);
+
+	return ret;
+}
+
+/* configure CSI-2 link between host and IVSC */
+static int csi_set_link_cfg(struct mei_csi *csi)
+{
+	struct csi_cmd cmd = { 0 };
+	size_t cmd_size;
+	int ret;
+
+	cmd.cmd_id = CSI_SET_CONF;
+	cmd.param.conf.nr_of_lanes = csi->nr_of_lanes;
+	cmd.param.conf.link_freq = CSI_LINK_FREQ(csi->link_freq);
+	cmd_size = sizeof(cmd.cmd_id) + sizeof(cmd.param.conf);
+
+	mutex_lock(&csi->lock);
+
+	ret = mei_csi_send(csi, (u8 *)&cmd, cmd_size);
+	/*
+	 * wait configuration ready if download success. placing
+	 * delay under mutex is to make sure current command flow
+	 * completed before starting a possible new one.
+	 */
+	if (!ret)
+		msleep(CSI_FW_READY_DELAY_MS);
+
+	mutex_unlock(&csi->lock);
+
+	return ret;
+}
+
+/* callback for receive */
+static void mei_csi_rx(struct mei_cl_device *cldev)
+{
+	struct mei_csi *csi = mei_cldev_get_drvdata(cldev);
+	struct csi_notif notif = { 0 };
+	int ret;
+
+	ret = mei_cldev_recv(cldev, (u8 *)&notif, sizeof(notif));
+	if (ret < 0) {
+		dev_err(&cldev->dev, "recv error: %d\n", ret);
+		return;
+	}
+
+	switch (notif.cmd_id) {
+	case CSI_PRIVACY_NOTIF:
+		if (notif.cont.cont < CSI_PRIVACY_MAX) {
+			csi->status = notif.cont.cont;
+			v4l2_ctrl_s_ctrl(csi->privacy_ctrl, csi->status);
+		}
+		break;
+	case CSI_SET_OWNER:
+	case CSI_SET_CONF:
+		memcpy(&csi->cmd_response, &notif, ret);
+
+		complete(&csi->cmd_completion);
+		break;
+	default:
+		break;
+	}
+}
+
+static int mei_csi_set_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct mei_csi *csi = sd_to_csi(sd);
+	s64 freq;
+	int ret;
+
+	if (enable && csi->streaming == 0) {
+		freq = v4l2_get_link_freq(csi->remote->ctrl_handler, 0, 0);
+		if (freq < 0) {
+			dev_err(&csi->cldev->dev,
+				"error %lld, invalid link_freq\n", freq);
+			ret = freq;
+			goto err;
+		}
+		csi->link_freq = freq;
+
+		/* switch CSI-2 link to host */
+		ret = csi_set_link_owner(csi, CSI_LINK_HOST);
+		if (ret < 0)
+			goto err;
+
+		/* configure CSI-2 link */
+		ret = csi_set_link_cfg(csi);
+		if (ret < 0)
+			goto err_switch;
+
+		ret = v4l2_subdev_call(csi->remote, video, s_stream, 1);
+		if (ret)
+			goto err_switch;
+	} else if (!enable && csi->streaming == 1) {
+		v4l2_subdev_call(csi->remote, video, s_stream, 0);
+
+		/* switch CSI-2 link to IVSC */
+		ret = csi_set_link_owner(csi, CSI_LINK_IVSC);
+		if (ret < 0)
+			dev_warn(&csi->cldev->dev,
+				 "failed to switch CSI2 link: %d\n", ret);
+	}
+
+	csi->streaming = enable;
+
+	return 0;
+
+err_switch:
+	csi_set_link_owner(csi, CSI_LINK_IVSC);
+
+err:
+	return ret;
+}
+
+static struct v4l2_mbus_framefmt *
+mei_csi_get_pad_format(struct v4l2_subdev *sd,
+		       struct v4l2_subdev_state *sd_state,
+		       unsigned int pad, u32 which)
+{
+	struct mei_csi *csi = sd_to_csi(sd);
+
+	switch (which) {
+	case V4L2_SUBDEV_FORMAT_TRY:
+		return v4l2_subdev_get_try_format(sd, sd_state, pad);
+	case V4L2_SUBDEV_FORMAT_ACTIVE:
+		return &csi->format_mbus[pad];
+	default:
+		return NULL;
+	}
+}
+
+static int mei_csi_init_cfg(struct v4l2_subdev *sd,
+			    struct v4l2_subdev_state *sd_state)
+{
+	struct v4l2_mbus_framefmt *mbusformat;
+	struct mei_csi *csi = sd_to_csi(sd);
+	unsigned int i;
+
+	mutex_lock(&csi->lock);
+
+	for (i = 0; i < sd->entity.num_pads; i++) {
+		mbusformat = v4l2_subdev_get_try_format(sd, sd_state, i);
+		*mbusformat = mei_csi_format_mbus_default;
+	}
+
+	mutex_unlock(&csi->lock);
+
+	return 0;
+}
+
+static int mei_csi_get_fmt(struct v4l2_subdev *sd,
+			   struct v4l2_subdev_state *sd_state,
+			   struct v4l2_subdev_format *format)
+{
+	struct v4l2_mbus_framefmt *mbusformat;
+	struct mei_csi *csi = sd_to_csi(sd);
+
+	mutex_lock(&csi->lock);
+
+	mbusformat = mei_csi_get_pad_format(sd, sd_state, format->pad,
+					    format->which);
+	if (mbusformat)
+		format->format = *mbusformat;
+
+	mutex_unlock(&csi->lock);
+
+	return 0;
+}
+
+static int mei_csi_set_fmt(struct v4l2_subdev *sd,
+			   struct v4l2_subdev_state *sd_state,
+			   struct v4l2_subdev_format *format)
+{
+	struct v4l2_mbus_framefmt *source_mbusformat;
+	struct v4l2_mbus_framefmt *mbusformat;
+	struct mei_csi *csi = sd_to_csi(sd);
+	struct media_pad *pad;
+
+	mbusformat = mei_csi_get_pad_format(sd, sd_state, format->pad,
+					    format->which);
+	if (!mbusformat)
+		return -EINVAL;
+
+	source_mbusformat = mei_csi_get_pad_format(sd, sd_state, CSI_PAD_SOURCE,
+						   format->which);
+	if (!source_mbusformat)
+		return -EINVAL;
+
+	v4l_bound_align_image(&format->format.width, 1, 65536, 0,
+			      &format->format.height, 1, 65536, 0, 0);
+
+	switch (format->format.code) {
+	case MEDIA_BUS_FMT_RGB444_1X12:
+	case MEDIA_BUS_FMT_RGB444_2X8_PADHI_BE:
+	case MEDIA_BUS_FMT_RGB444_2X8_PADHI_LE:
+	case MEDIA_BUS_FMT_RGB555_2X8_PADHI_BE:
+	case MEDIA_BUS_FMT_RGB555_2X8_PADHI_LE:
+	case MEDIA_BUS_FMT_RGB565_1X16:
+	case MEDIA_BUS_FMT_BGR565_2X8_BE:
+	case MEDIA_BUS_FMT_BGR565_2X8_LE:
+	case MEDIA_BUS_FMT_RGB565_2X8_BE:
+	case MEDIA_BUS_FMT_RGB565_2X8_LE:
+	case MEDIA_BUS_FMT_RGB666_1X18:
+	case MEDIA_BUS_FMT_RBG888_1X24:
+	case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
+	case MEDIA_BUS_FMT_BGR888_1X24:
+	case MEDIA_BUS_FMT_GBR888_1X24:
+	case MEDIA_BUS_FMT_RGB888_1X24:
+	case MEDIA_BUS_FMT_RGB888_2X12_BE:
+	case MEDIA_BUS_FMT_RGB888_2X12_LE:
+	case MEDIA_BUS_FMT_ARGB8888_1X32:
+	case MEDIA_BUS_FMT_RGB888_1X32_PADHI:
+	case MEDIA_BUS_FMT_RGB101010_1X30:
+	case MEDIA_BUS_FMT_RGB121212_1X36:
+	case MEDIA_BUS_FMT_RGB161616_1X48:
+	case MEDIA_BUS_FMT_Y8_1X8:
+	case MEDIA_BUS_FMT_UV8_1X8:
+	case MEDIA_BUS_FMT_UYVY8_1_5X8:
+	case MEDIA_BUS_FMT_VYUY8_1_5X8:
+	case MEDIA_BUS_FMT_YUYV8_1_5X8:
+	case MEDIA_BUS_FMT_YVYU8_1_5X8:
+	case MEDIA_BUS_FMT_UYVY8_2X8:
+	case MEDIA_BUS_FMT_VYUY8_2X8:
+	case MEDIA_BUS_FMT_YUYV8_2X8:
+	case MEDIA_BUS_FMT_YVYU8_2X8:
+	case MEDIA_BUS_FMT_Y10_1X10:
+	case MEDIA_BUS_FMT_UYVY10_2X10:
+	case MEDIA_BUS_FMT_VYUY10_2X10:
+	case MEDIA_BUS_FMT_YUYV10_2X10:
+	case MEDIA_BUS_FMT_YVYU10_2X10:
+	case MEDIA_BUS_FMT_Y12_1X12:
+	case MEDIA_BUS_FMT_UYVY12_2X12:
+	case MEDIA_BUS_FMT_VYUY12_2X12:
+	case MEDIA_BUS_FMT_YUYV12_2X12:
+	case MEDIA_BUS_FMT_YVYU12_2X12:
+	case MEDIA_BUS_FMT_UYVY8_1X16:
+	case MEDIA_BUS_FMT_VYUY8_1X16:
+	case MEDIA_BUS_FMT_YUYV8_1X16:
+	case MEDIA_BUS_FMT_YVYU8_1X16:
+	case MEDIA_BUS_FMT_YDYUYDYV8_1X16:
+	case MEDIA_BUS_FMT_UYVY10_1X20:
+	case MEDIA_BUS_FMT_VYUY10_1X20:
+	case MEDIA_BUS_FMT_YUYV10_1X20:
+	case MEDIA_BUS_FMT_YVYU10_1X20:
+	case MEDIA_BUS_FMT_VUY8_1X24:
+	case MEDIA_BUS_FMT_YUV8_1X24:
+	case MEDIA_BUS_FMT_UYYVYY8_0_5X24:
+	case MEDIA_BUS_FMT_UYVY12_1X24:
+	case MEDIA_BUS_FMT_VYUY12_1X24:
+	case MEDIA_BUS_FMT_YUYV12_1X24:
+	case MEDIA_BUS_FMT_YVYU12_1X24:
+	case MEDIA_BUS_FMT_YUV10_1X30:
+	case MEDIA_BUS_FMT_UYYVYY10_0_5X30:
+	case MEDIA_BUS_FMT_AYUV8_1X32:
+	case MEDIA_BUS_FMT_UYYVYY12_0_5X36:
+	case MEDIA_BUS_FMT_YUV12_1X36:
+	case MEDIA_BUS_FMT_YUV16_1X48:
+	case MEDIA_BUS_FMT_UYYVYY16_0_5X48:
+	case MEDIA_BUS_FMT_JPEG_1X8:
+	case MEDIA_BUS_FMT_AHSV8888_1X32:
+	case MEDIA_BUS_FMT_SBGGR8_1X8:
+	case MEDIA_BUS_FMT_SGBRG8_1X8:
+	case MEDIA_BUS_FMT_SGRBG8_1X8:
+	case MEDIA_BUS_FMT_SRGGB8_1X8:
+	case MEDIA_BUS_FMT_SBGGR10_1X10:
+	case MEDIA_BUS_FMT_SGBRG10_1X10:
+	case MEDIA_BUS_FMT_SGRBG10_1X10:
+	case MEDIA_BUS_FMT_SRGGB10_1X10:
+	case MEDIA_BUS_FMT_SBGGR12_1X12:
+	case MEDIA_BUS_FMT_SGBRG12_1X12:
+	case MEDIA_BUS_FMT_SGRBG12_1X12:
+	case MEDIA_BUS_FMT_SRGGB12_1X12:
+	case MEDIA_BUS_FMT_SBGGR14_1X14:
+	case MEDIA_BUS_FMT_SGBRG14_1X14:
+	case MEDIA_BUS_FMT_SGRBG14_1X14:
+	case MEDIA_BUS_FMT_SRGGB14_1X14:
+	case MEDIA_BUS_FMT_SBGGR16_1X16:
+	case MEDIA_BUS_FMT_SGBRG16_1X16:
+	case MEDIA_BUS_FMT_SGRBG16_1X16:
+	case MEDIA_BUS_FMT_SRGGB16_1X16:
+		break;
+	default:
+		format->format.code = MEDIA_BUS_FMT_Y8_1X8;
+		break;
+	}
+
+	if (format->format.field == V4L2_FIELD_ANY)
+		format->format.field = V4L2_FIELD_NONE;
+
+	mutex_lock(&csi->lock);
+
+	pad = &csi->pads[format->pad];
+	if (pad->flags & MEDIA_PAD_FL_SOURCE)
+		format->format = csi->format_mbus[CSI_PAD_SINK];
+
+	*mbusformat = format->format;
+
+	if (pad->flags & MEDIA_PAD_FL_SINK)
+		*source_mbusformat = format->format;
+
+	mutex_unlock(&csi->lock);
+
+	return 0;
+}
+
+static int mei_csi_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct mei_csi *csi = ctrl_to_csi(ctrl);
+	s64 freq;
+
+	if (ctrl->id == V4L2_CID_LINK_FREQ) {
+		if (!csi->remote)
+			return -EINVAL;
+
+		freq = v4l2_get_link_freq(csi->remote->ctrl_handler, 0, 0);
+		if (freq < 0) {
+			dev_err(&csi->cldev->dev,
+				"error %lld, invalid link_freq\n", freq);
+			return -EINVAL;
+		}
+
+		ctrl->val = freq;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static const struct v4l2_ctrl_ops mei_csi_ctrl_ops = {
+	.g_volatile_ctrl = mei_csi_g_volatile_ctrl,
+};
+
+static const struct v4l2_subdev_video_ops mei_csi_video_ops = {
+	.s_stream = mei_csi_set_stream,
+};
+
+static const struct v4l2_subdev_pad_ops mei_csi_pad_ops = {
+	.init_cfg = mei_csi_init_cfg,
+	.get_fmt = mei_csi_get_fmt,
+	.set_fmt = mei_csi_set_fmt,
+};
+
+static const struct v4l2_subdev_ops mei_csi_subdev_ops = {
+	.video = &mei_csi_video_ops,
+	.pad = &mei_csi_pad_ops,
+};
+
+static const struct media_entity_operations mei_csi_entity_ops = {
+	.link_validate = v4l2_subdev_link_validate,
+};
+
+static int mei_csi_notify_bound(struct v4l2_async_notifier *notifier,
+				struct v4l2_subdev *subdev,
+				struct v4l2_async_subdev *asd)
+{
+	struct mei_csi *csi = notifier_to_csi(notifier);
+	int pad;
+
+	pad = media_entity_get_fwnode_pad(&subdev->entity, asd->match.fwnode,
+					  MEDIA_PAD_FL_SOURCE);
+	if (pad < 0)
+		return pad;
+
+	csi->remote = subdev;
+	csi->remote_pad = pad;
+
+	return media_create_pad_link(&subdev->entity, pad,
+				     &csi->subdev.entity, 0,
+				     MEDIA_LNK_FL_ENABLED |
+				     MEDIA_LNK_FL_IMMUTABLE);
+}
+
+static void mei_csi_notify_unbind(struct v4l2_async_notifier *notifier,
+				  struct v4l2_subdev *subdev,
+				  struct v4l2_async_subdev *asd)
+{
+	struct mei_csi *csi = notifier_to_csi(notifier);
+
+	csi->remote = NULL;
+}
+
+static const struct v4l2_async_notifier_operations mei_csi_notify_ops = {
+	.bound = mei_csi_notify_bound,
+	.unbind = mei_csi_notify_unbind,
+};
+
+static int mei_csi_init_controls(struct mei_csi *csi)
+{
+	int ret;
+
+	ret = v4l2_ctrl_handler_init(&csi->ctrl_handler, 2);
+	if (ret)
+		return ret;
+
+	csi->ctrl_handler.lock = &csi->lock;
+
+	csi->freq_ctrl = v4l2_ctrl_new_std(&csi->ctrl_handler,
+					   &mei_csi_ctrl_ops,
+					   V4L2_CID_LINK_FREQ, 0,
+					   2500 * HZ_PER_MHZ, 1, 0);
+	if (csi->freq_ctrl)
+		csi->freq_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY |
+					 V4L2_CTRL_FLAG_VOLATILE;
+
+	csi->privacy_ctrl = v4l2_ctrl_new_std(&csi->ctrl_handler, NULL,
+					      V4L2_CID_PRIVACY, 0, 1, 1, 0);
+	if (csi->privacy_ctrl)
+		csi->privacy_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
+	if (csi->ctrl_handler.error)
+		return csi->ctrl_handler.error;
+
+	csi->subdev.ctrl_handler = &csi->ctrl_handler;
+
+	return 0;
+}
+
+static int mei_csi_parse_firmware(struct mei_csi *csi)
+{
+	struct v4l2_fwnode_endpoint v4l2_ep = {
+		.bus_type = V4L2_MBUS_CSI2_DPHY,
+	};
+	struct device *dev = &csi->cldev->dev;
+	struct v4l2_async_subdev *asd;
+	struct fwnode_handle *fwnode;
+	struct fwnode_handle *ep;
+	int ret;
+
+	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), 0, 0, 0);
+	if (!ep) {
+		dev_err(dev, "not connected to subdevice\n");
+		return -EINVAL;
+	}
+
+	ret = v4l2_fwnode_endpoint_parse(ep, &v4l2_ep);
+	if (ret) {
+		dev_err(dev, "could not parse v4l2 endpoint\n");
+		fwnode_handle_put(ep);
+		return -EINVAL;
+	}
+
+	fwnode = fwnode_graph_get_remote_endpoint(ep);
+	fwnode_handle_put(ep);
+
+	v4l2_async_nf_init(&csi->notifier);
+	csi->notifier.ops = &mei_csi_notify_ops;
+
+	asd = v4l2_async_nf_add_fwnode(&csi->notifier, fwnode,
+				       struct v4l2_async_subdev);
+	if (IS_ERR(asd)) {
+		fwnode_handle_put(fwnode);
+		return PTR_ERR(asd);
+	}
+
+	ret = v4l2_fwnode_endpoint_alloc_parse(fwnode, &v4l2_ep);
+	fwnode_handle_put(fwnode);
+	if (ret)
+		return ret;
+	csi->nr_of_lanes = v4l2_ep.bus.mipi_csi2.num_data_lanes;
+
+	ret = v4l2_async_subdev_nf_register(&csi->subdev, &csi->notifier);
+	if (ret)
+		v4l2_async_nf_cleanup(&csi->notifier);
+
+	v4l2_fwnode_endpoint_free(&v4l2_ep);
+
+	return ret;
+}
+
+static int mei_csi_probe(struct mei_cl_device *cldev,
+			 const struct mei_cl_device_id *id)
+{
+	struct device *dev = &cldev->dev;
+	struct mei_csi *csi;
+	int ret;
+
+	if (!dev_fwnode(dev))
+		return -EPROBE_DEFER;
+
+	csi = devm_kzalloc(dev, sizeof(struct mei_csi), GFP_KERNEL);
+	if (!csi)
+		return -ENOMEM;
+
+	csi->cldev = cldev;
+	mutex_init(&csi->lock);
+	init_completion(&csi->cmd_completion);
+
+	mei_cldev_set_drvdata(cldev, csi);
+
+	ret = mei_cldev_enable(cldev);
+	if (ret < 0) {
+		dev_err(dev, "mei_cldev_enable failed: %d\n", ret);
+		goto destroy_mutex;
+	}
+
+	ret = mei_cldev_register_rx_cb(cldev, mei_csi_rx);
+	if (ret) {
+		dev_err(dev, "event cb registration failed: %d\n", ret);
+		goto err_disable;
+	}
+
+	ret = mei_csi_parse_firmware(csi);
+	if (ret)
+		goto err_disable;
+
+	csi->subdev.dev = &cldev->dev;
+	v4l2_subdev_init(&csi->subdev, &mei_csi_subdev_ops);
+	v4l2_set_subdevdata(&csi->subdev, csi);
+	csi->subdev.flags = V4L2_SUBDEV_FL_HAS_DEVNODE |
+			    V4L2_SUBDEV_FL_HAS_EVENTS;
+	csi->subdev.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
+	csi->subdev.entity.ops = &mei_csi_entity_ops;
+
+	ret = mei_csi_init_controls(csi);
+	if (ret)
+		goto err_ctrl_handler;
+
+	csi->format_mbus[CSI_PAD_SOURCE] = mei_csi_format_mbus_default;
+	csi->format_mbus[CSI_PAD_SINK] = mei_csi_format_mbus_default;
+
+	csi->pads[CSI_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
+	csi->pads[CSI_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
+	ret = media_entity_pads_init(&csi->subdev.entity, CSI_NUM_PADS,
+				     csi->pads);
+	if (ret)
+		goto err_ctrl_handler;
+
+	ret = v4l2_subdev_init_finalize(&csi->subdev);
+	if (ret < 0)
+		goto err_entity;
+
+	ret = v4l2_async_register_subdev(&csi->subdev);
+	if (ret < 0)
+		goto err_subdev;
+
+	pm_runtime_enable(&cldev->dev);
+
+	return 0;
+
+err_subdev:
+	v4l2_subdev_cleanup(&csi->subdev);
+
+err_entity:
+	media_entity_cleanup(&csi->subdev.entity);
+
+err_ctrl_handler:
+	v4l2_ctrl_handler_free(&csi->ctrl_handler);
+	v4l2_async_nf_unregister(&csi->notifier);
+	v4l2_async_nf_cleanup(&csi->notifier);
+
+err_disable:
+	mei_cldev_disable(cldev);
+
+destroy_mutex:
+	mutex_destroy(&csi->lock);
+
+	return ret;
+}
+
+static void mei_csi_remove(struct mei_cl_device *cldev)
+{
+	struct mei_csi *csi = mei_cldev_get_drvdata(cldev);
+
+	v4l2_async_nf_unregister(&csi->notifier);
+	v4l2_async_nf_cleanup(&csi->notifier);
+	v4l2_ctrl_handler_free(&csi->ctrl_handler);
+	v4l2_async_unregister_subdev(&csi->subdev);
+	v4l2_subdev_cleanup(&csi->subdev);
+	media_entity_cleanup(&csi->subdev.entity);
+
+	pm_runtime_disable(&cldev->dev);
+
+	mutex_destroy(&csi->lock);
+}
+
+#define MEI_CSI_UUID GUID_INIT(0x92335FCF, 0x3203, 0x4472, \
+			       0xAF, 0x93, 0x7b, 0x44, 0x53, 0xAC, 0x29, 0xDA)
+
+static const struct mei_cl_device_id mei_csi_tbl[] = {
+	{ MEI_CSI_DRIVER_NAME, MEI_CSI_UUID, MEI_CL_VERSION_ANY },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(mei, mei_csi_tbl);
+
+static struct mei_cl_driver mei_csi_driver = {
+	.id_table = mei_csi_tbl,
+	.name = MEI_CSI_DRIVER_NAME,
+
+	.probe = mei_csi_probe,
+	.remove = mei_csi_remove,
+};
+
+module_mei_cl_driver(mei_csi_driver);
+
+MODULE_AUTHOR("Wentong Wu <wentong.wu@intel.com>");
+MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@intel.com>");
+MODULE_DESCRIPTION("Device driver for IVSC CSI");
+MODULE_LICENSE("GPL");
-- 
2.7.4

[PATCH v8 2/3] media: pci: intel: ivsc: Add ACE submodule

[Wentong Wu]

ACE is a submodule of IVSC which controls camera sensor's
ownership, belonging to host or IVSC. When IVSC owns camera
sensor, it is for algorithm computing. When host wants to
control camera sensor, ACE module needs to be informed of
ownership with defined interface.

The interface is via MEI. There is a separate MEI UUID, which
this driver uses to enumerate.

To switch ownership of camera sensor between IVSC and host,
the caller specifies the defined ownership information which
will be sent to firmware by sending MEI command.

Device link(device_link_add) is used to set the right camera
sensor ownership before accessing the sensor via I2C. With
DL_FLAG_PM_RUNTIME and DL_FLAG_RPM_ACTIVE, the supplier device
will be PM runtime resumed before the consumer(camera sensor).
So use runtime PM callbacks to transfer the ownership between
host and IVSC.

Signed-off-by: Wentong Wu <wentong.wu@intel.com>
---
 drivers/media/pci/intel/ivsc/Makefile  |   3 +
 drivers/media/pci/intel/ivsc/mei_ace.c | 591 +++++++++++++++++++++++++++++++++
 2 files changed, 594 insertions(+)
 create mode 100644 drivers/media/pci/intel/ivsc/mei_ace.c

diff --git a/drivers/media/pci/intel/ivsc/Makefile b/drivers/media/pci/intel/ivsc/Makefile
index cbd194a..00fad29 100644
--- a/drivers/media/pci/intel/ivsc/Makefile
+++ b/drivers/media/pci/intel/ivsc/Makefile
@@ -4,3 +4,6 @@
 
 obj-$(CONFIG_INTEL_VSC) += ivsc-csi.o
 ivsc-csi-y += mei_csi.o
+
+obj-$(CONFIG_INTEL_VSC) += ivsc-ace.o
+ivsc-ace-y += mei_ace.o
diff --git a/drivers/media/pci/intel/ivsc/mei_ace.c b/drivers/media/pci/intel/ivsc/mei_ace.c
new file mode 100644
index 0000000..740a404
--- /dev/null
+++ b/drivers/media/pci/intel/ivsc/mei_ace.c
@@ -0,0 +1,591 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023 Intel Corporation. All rights reserved.
+ * Intel Visual Sensing Controller ACE Linux driver
+ */
+
+/*
+ * To set ownership of camera sensor, there is specific command, which
+ * is sent via MEI protocol. That's a two-step scheme where the firmware
+ * first acks receipt of the command and later responses the command was
+ * executed. The command sending function uses "completion" as the
+ * synchronization mechanism. The notification for command is received
+ * via a mei callback which wakes up the caller. There can be only one
+ * outstanding command at a time.
+ *
+ * The power line of camera sensor is directly connected to IVSC instead
+ * of host, when camera sensor ownership is switched to host, sensor is
+ * already powered up by firmware.
+ */
+
+#include <linux/acpi.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/mei_cl_bus.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/uuid.h>
+
+#define	MEI_ACE_DRIVER_NAME	"ivsc_ace"
+
+/* indicating driver message */
+#define	ACE_DRV_MSG		1
+/* indicating set command */
+#define	ACE_CMD_SET		4
+/* command timeout determined experimentally */
+#define	ACE_CMD_TIMEOUT		(5 * HZ)
+/* indicating the first command block */
+#define	ACE_CMD_INIT_BLOCK	1
+/* indicating the last command block */
+#define	ACE_CMD_FINAL_BLOCK	1
+/* size of camera status notification content */
+#define	ACE_CAMERA_STATUS_SIZE	5
+
+/* UUID used to get firmware id */
+#define ACE_GET_FW_ID_UUID GUID_INIT(0x6167DCFB, 0x72F1, 0x4584, 0xBF, \
+				     0xE3, 0x84, 0x17, 0x71, 0xAA, 0x79, 0x0B)
+
+/* UUID used to get csi device */
+#define MEI_CSI_UUID GUID_INIT(0x92335FCF, 0x3203, 0x4472, \
+			       0xAF, 0x93, 0x7b, 0x44, 0x53, 0xAC, 0x29, 0xDA)
+
+/* identify firmware event type */
+enum ace_event_type {
+	/* firmware ready */
+	ACE_FW_READY = 0x8,
+
+	/* command response */
+	ACE_CMD_RESPONSE = 0x10,
+};
+
+/* identify camera sensor ownership */
+enum ace_camera_owner {
+	ACE_CAMERA_IVSC,
+	ACE_CAMERA_HOST,
+};
+
+/* identify the command id supported by firmware IPC */
+enum ace_cmd_id {
+	/* used to switch camera sensor to host */
+	ACE_SWITCH_CAMERA_TO_HOST = 0x13,
+
+	/* used to switch camera sensor to IVSC */
+	ACE_SWITCH_CAMERA_TO_IVSC = 0x14,
+
+	/* used to get firmware id */
+	ACE_GET_FW_ID = 0x1A,
+};
+
+/* ACE command header structure */
+struct ace_cmd_hdr {
+	u32 firmware_id : 16;
+	u32 instance_id : 8;
+	u32 type : 5;
+	u32 rsp : 1;
+	u32 msg_tgt : 1;
+	u32 _hw_rsvd_1 : 1;
+	u32 param_size : 20;
+	u32 cmd_id : 8;
+	u32 final_block : 1;
+	u32 init_block : 1;
+	u32 _hw_rsvd_2 : 2;
+} __packed;
+
+/* ACE command parameter structure */
+union ace_cmd_param {
+	guid_t uuid;
+	u32 param;
+};
+
+/* ACE command structure */
+struct ace_cmd {
+	struct ace_cmd_hdr hdr;
+	union ace_cmd_param param;
+} __packed;
+
+/* ACE notification header */
+union ace_notif_hdr {
+	struct _confirm {
+		u32 status : 24;
+		u32 type : 5;
+		u32 rsp : 1;
+		u32 msg_tgt : 1;
+		u32 _hw_rsvd_1 : 1;
+		u32 param_size : 20;
+		u32 cmd_id : 8;
+		u32 final_block : 1;
+		u32 init_block : 1;
+		u32 _hw_rsvd_2 : 2;
+	} __packed ack;
+
+	struct _event {
+		u32 rsvd1 : 16;
+		u32 event_type : 8;
+		u32 type : 5;
+		u32 ack : 1;
+		u32 msg_tgt : 1;
+		u32 _hw_rsvd_1 : 1;
+		u32 rsvd2 : 30;
+		u32 _hw_rsvd_2 : 2;
+	} __packed event;
+
+	struct _response {
+		u32 event_id : 16;
+		u32 notif_type : 8;
+		u32 type : 5;
+		u32 rsp : 1;
+		u32 msg_tgt : 1;
+		u32 _hw_rsvd_1 : 1;
+		u32 event_data_size : 16;
+		u32 request_target : 1;
+		u32 request_type : 5;
+		u32 cmd_id : 8;
+		u32 _hw_rsvd_2 : 2;
+	} __packed response;
+};
+
+/* ACE notification content */
+union ace_notif_cont {
+	u16 firmware_id;
+	u8 state_notif;
+	u8 camera_status[ACE_CAMERA_STATUS_SIZE];
+};
+
+/* ACE notification structure */
+struct ace_notif {
+	union ace_notif_hdr hdr;
+	union ace_notif_cont cont;
+} __packed;
+
+struct mei_ace {
+	struct mei_cl_device *cldev;
+
+	/* command ack */
+	struct ace_notif cmd_ack;
+	/* command response */
+	struct ace_notif cmd_response;
+	/* used to wait for command ack and response */
+	struct completion cmd_completion;
+	/* lock used to prevent multiple call to send command */
+	struct mutex lock;
+
+	/* used to construct command */
+	u16 firmware_id;
+
+	struct device *csi_dev;
+	struct acpi_device *sensor_adev;
+
+	/* runtime PM link from ace to csi */
+	struct device_link *csi_link;
+	/* runtime PM link from ace to sensor */
+	struct device_link *sensor_link;
+};
+
+static inline void init_cmd_hdr(struct ace_cmd_hdr *hdr)
+{
+	memset(hdr, 0, sizeof(struct ace_cmd_hdr));
+
+	hdr->type = ACE_CMD_SET;
+	hdr->msg_tgt = ACE_DRV_MSG;
+	hdr->init_block = ACE_CMD_INIT_BLOCK;
+	hdr->final_block = ACE_CMD_FINAL_BLOCK;
+}
+
+static int construct_command(struct mei_ace *ace, struct ace_cmd *cmd,
+			     enum ace_cmd_id cmd_id)
+{
+	union ace_cmd_param *param = &cmd->param;
+	struct ace_cmd_hdr *hdr = &cmd->hdr;
+
+	init_cmd_hdr(hdr);
+
+	hdr->cmd_id = cmd_id;
+	switch (cmd_id) {
+	case ACE_GET_FW_ID:
+		param->uuid = ACE_GET_FW_ID_UUID;
+		hdr->param_size = sizeof(param->uuid);
+		break;
+	case ACE_SWITCH_CAMERA_TO_IVSC:
+		param->param = 0;
+		hdr->firmware_id = ace->firmware_id;
+		hdr->param_size = sizeof(param->param);
+		break;
+	case ACE_SWITCH_CAMERA_TO_HOST:
+		hdr->firmware_id = ace->firmware_id;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return hdr->param_size + sizeof(cmd->hdr);
+}
+
+/* send command to firmware */
+static int mei_ace_send(struct mei_ace *ace, struct ace_cmd *cmd,
+			size_t len, bool only_ack)
+{
+	union ace_notif_hdr *resp_hdr = &ace->cmd_response.hdr;
+	union ace_notif_hdr *ack_hdr = &ace->cmd_ack.hdr;
+	struct ace_cmd_hdr *cmd_hdr = &cmd->hdr;
+	int ret;
+
+	mutex_lock(&ace->lock);
+
+	reinit_completion(&ace->cmd_completion);
+
+	ret = mei_cldev_send(ace->cldev, (u8 *)cmd, len);
+	if (ret < 0)
+		goto out;
+
+	ret = wait_for_completion_killable_timeout(&ace->cmd_completion,
+						   ACE_CMD_TIMEOUT);
+	if (ret < 0) {
+		goto out;
+	} else if (!ret) {
+		ret = -ETIMEDOUT;
+		goto out;
+	}
+
+	if (ack_hdr->ack.cmd_id != cmd_hdr->cmd_id) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* command ack status */
+	ret = ack_hdr->ack.status;
+	if (ret) {
+		ret = -EIO;
+		goto out;
+	}
+
+	if (only_ack)
+		goto out;
+
+	ret = wait_for_completion_killable_timeout(&ace->cmd_completion,
+						   ACE_CMD_TIMEOUT);
+	if (ret < 0) {
+		goto out;
+	} else if (!ret) {
+		ret = -ETIMEDOUT;
+		goto out;
+	}
+
+	if (resp_hdr->response.cmd_id != cmd_hdr->cmd_id)
+		ret = -EINVAL;
+
+out:
+	mutex_unlock(&ace->lock);
+
+	return ret;
+}
+
+static int ace_set_camera_owner(struct mei_ace *ace,
+				enum ace_camera_owner owner)
+{
+	enum ace_cmd_id cmd_id;
+	struct ace_cmd cmd;
+	int cmd_size;
+	int ret;
+
+	if (owner == ACE_CAMERA_IVSC)
+		cmd_id = ACE_SWITCH_CAMERA_TO_IVSC;
+	else
+		cmd_id = ACE_SWITCH_CAMERA_TO_HOST;
+
+	cmd_size = construct_command(ace, &cmd, cmd_id);
+	if (cmd_size >= 0)
+		ret = mei_ace_send(ace, &cmd, cmd_size, false);
+	else
+		ret = cmd_size;
+
+	return ret;
+}
+
+/* the first command downloaded to firmware */
+static inline int ace_get_firmware_id(struct mei_ace *ace)
+{
+	struct ace_cmd cmd;
+	int cmd_size;
+	int ret;
+
+	cmd_size = construct_command(ace, &cmd, ACE_GET_FW_ID);
+	if (cmd_size >= 0)
+		ret = mei_ace_send(ace, &cmd, cmd_size, true);
+	else
+		ret = cmd_size;
+
+	return ret;
+}
+
+static void handle_command_response(struct mei_ace *ace,
+				    struct ace_notif *resp, int len)
+{
+	union ace_notif_hdr *hdr = &resp->hdr;
+
+	switch (hdr->response.cmd_id) {
+	case ACE_SWITCH_CAMERA_TO_IVSC:
+	case ACE_SWITCH_CAMERA_TO_HOST:
+		memcpy(&ace->cmd_response, resp, len);
+		complete(&ace->cmd_completion);
+		break;
+	case ACE_GET_FW_ID:
+		break;
+	default:
+		break;
+	}
+}
+
+static void handle_command_ack(struct mei_ace *ace,
+			       struct ace_notif *ack, int len)
+{
+	union ace_notif_hdr *hdr = &ack->hdr;
+
+	switch (hdr->ack.cmd_id) {
+	case ACE_GET_FW_ID:
+		ace->firmware_id = ack->cont.firmware_id;
+		fallthrough;
+	case ACE_SWITCH_CAMERA_TO_IVSC:
+	case ACE_SWITCH_CAMERA_TO_HOST:
+		memcpy(&ace->cmd_ack, ack, len);
+		complete(&ace->cmd_completion);
+		break;
+	default:
+		break;
+	}
+}
+
+/* callback for receive */
+static void mei_ace_rx(struct mei_cl_device *cldev)
+{
+	struct mei_ace *ace = mei_cldev_get_drvdata(cldev);
+	struct ace_notif event;
+	union ace_notif_hdr *hdr = &event.hdr;
+	int ret;
+
+	ret = mei_cldev_recv(cldev, (u8 *)&event, sizeof(event));
+	if (ret < 0) {
+		dev_err(&cldev->dev, "recv error: %d\n", ret);
+		return;
+	}
+
+	if (hdr->event.ack) {
+		handle_command_ack(ace, &event, ret);
+		return;
+	}
+
+	switch (hdr->event.event_type) {
+	case ACE_CMD_RESPONSE:
+		handle_command_response(ace, &event, ret);
+		break;
+	case ACE_FW_READY:
+		/*
+		 * firmware ready notification sent to driver
+		 * after HECI client connected with firmware.
+		 */
+		dev_dbg(&cldev->dev, "firmware ready\n");
+		break;
+	default:
+		break;
+	}
+}
+
+static int mei_ace_setup_dev_link(struct mei_ace *ace)
+{
+	struct device *dev = &ace->cldev->dev;
+	guid_t uuid = MEI_CSI_UUID;
+	struct acpi_device *adev;
+	struct device *csi_dev;
+	char name[64];
+	int ret;
+
+	snprintf(name, sizeof(name), "%s-%pUl", dev_name(dev->parent), &uuid);
+
+	csi_dev = device_find_child_by_name(dev->parent, name);
+	if (!csi_dev) {
+		ret = -EPROBE_DEFER;
+		goto err;
+	}
+
+	/* sensor's ACPI _DEP is mei bus device */
+	adev = acpi_dev_get_next_consumer_dev(ACPI_COMPANION(dev->parent),
+					      NULL);
+	if (!adev) {
+		ret = -EPROBE_DEFER;
+		goto err_put;
+	}
+
+	/* setup link between mei_ace and mei_csi */
+	ace->csi_link = device_link_add(csi_dev, dev, DL_FLAG_PM_RUNTIME |
+					DL_FLAG_RPM_ACTIVE);
+	if (!ace->csi_link) {
+		ret = -EINVAL;
+		dev_err(dev, "failed to link to %s\n", dev_name(csi_dev));
+		goto err_put_acpi;
+	}
+
+	/* setup link between mei_ace and sensor */
+	ace->sensor_link = device_link_add(&adev->dev, dev, DL_FLAG_PM_RUNTIME |
+					   DL_FLAG_RPM_ACTIVE);
+	if (!ace->sensor_link) {
+		ret = -EINVAL;
+		dev_err(dev, "failed to link to %s\n", dev_name(&adev->dev));
+		goto err_link;
+	}
+
+	ace->csi_dev = csi_dev;
+	ace->sensor_adev = adev;
+
+	return 0;
+
+err_link:
+	device_link_del(ace->csi_link);
+
+err_put_acpi:
+	acpi_dev_put(adev);
+
+err_put:
+	put_device(csi_dev);
+
+err:
+	return ret;
+}
+
+static int mei_ace_probe(struct mei_cl_device *cldev,
+			 const struct mei_cl_device_id *id)
+{
+	struct device *dev = &cldev->dev;
+	struct mei_ace *ace;
+	int ret;
+
+	ace = devm_kzalloc(dev, sizeof(struct mei_ace), GFP_KERNEL);
+	if (!ace)
+		return -ENOMEM;
+
+	ace->cldev = cldev;
+
+	ret = mei_ace_setup_dev_link(ace);
+	if (ret)
+		return ret;
+
+	mutex_init(&ace->lock);
+	init_completion(&ace->cmd_completion);
+
+	mei_cldev_set_drvdata(cldev, ace);
+
+	ret = mei_cldev_enable(cldev);
+	if (ret < 0) {
+		dev_err(dev, "mei_cldev_enable failed: %d\n", ret);
+		goto destroy_mutex;
+	}
+
+	ret = mei_cldev_register_rx_cb(cldev, mei_ace_rx);
+	if (ret) {
+		dev_err(dev, "event cb registration failed: %d\n", ret);
+		goto err_disable;
+	}
+
+	ret = ace_get_firmware_id(ace);
+	if (ret) {
+		dev_err(dev, "get firmware id failed: %d\n", ret);
+		goto err_disable;
+	}
+
+	if (IS_ENABLED(CONFIG_PM)) {
+		pm_runtime_set_active(dev);
+		pm_runtime_enable(dev);
+	} else {
+		ret = ace_set_camera_owner(ace, ACE_SWITCH_CAMERA_TO_HOST);
+		if (ret) {
+			dev_err(dev, "switch camera to host failed: %d\n", ret);
+			goto err_disable;
+		}
+	}
+
+	acpi_dev_clear_dependencies(ACPI_COMPANION(dev->parent));
+
+	return 0;
+
+err_disable:
+	mei_cldev_disable(cldev);
+
+destroy_mutex:
+	mutex_destroy(&ace->lock);
+
+	device_link_del(ace->csi_link);
+	device_link_del(ace->sensor_link);
+
+	put_device(ace->csi_dev);
+	acpi_dev_put(ace->sensor_adev);
+
+	return ret;
+}
+
+static void mei_ace_remove(struct mei_cl_device *cldev)
+{
+	struct mei_ace *ace = mei_cldev_get_drvdata(cldev);
+
+	device_link_del(ace->csi_link);
+	device_link_del(ace->sensor_link);
+
+	put_device(ace->csi_dev);
+	acpi_dev_put(ace->sensor_adev);
+
+	if (IS_ENABLED(CONFIG_PM)) {
+		pm_runtime_disable(&cldev->dev);
+		pm_runtime_set_suspended(&cldev->dev);
+	} else {
+		ace_set_camera_owner(ace, ACE_SWITCH_CAMERA_TO_IVSC);
+	}
+
+	mutex_destroy(&ace->lock);
+}
+
+static int __maybe_unused mei_ace_runtime_suspend(struct device *dev)
+{
+	struct mei_ace *ace = dev_get_drvdata(dev);
+
+	return ace_set_camera_owner(ace, ACE_SWITCH_CAMERA_TO_IVSC);
+}
+
+static int __maybe_unused mei_ace_runtime_resume(struct device *dev)
+{
+	struct mei_ace *ace = dev_get_drvdata(dev);
+
+	return ace_set_camera_owner(ace, ACE_SWITCH_CAMERA_TO_HOST);
+}
+
+static const struct dev_pm_ops mei_ace_pm_ops = {
+	SET_RUNTIME_PM_OPS(mei_ace_runtime_suspend,
+			   mei_ace_runtime_resume, NULL)
+};
+
+#define MEI_ACE_UUID GUID_INIT(0x5DB76CF6, 0x0A68, 0x4ED6, \
+			       0x9B, 0x78, 0x03, 0x61, 0x63, 0x5E, 0x24, 0x47)
+
+static const struct mei_cl_device_id mei_ace_tbl[] = {
+	{ MEI_ACE_DRIVER_NAME, MEI_ACE_UUID, MEI_CL_VERSION_ANY },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(mei, mei_ace_tbl);
+
+static struct mei_cl_driver mei_ace_driver = {
+	.id_table = mei_ace_tbl,
+	.name = MEI_ACE_DRIVER_NAME,
+
+	.probe = mei_ace_probe,
+	.remove = mei_ace_remove,
+
+	.driver = {
+		.pm = &mei_ace_pm_ops,
+	},
+};
+
+module_mei_cl_driver(mei_ace_driver);
+
+MODULE_AUTHOR("Wentong Wu <wentong.wu@intel.com>");
+MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@intel.com>");
+MODULE_DESCRIPTION("Device driver for IVSC ACE");
+MODULE_LICENSE("GPL");
-- 
2.7.4

[PATCH v8 3/3] ACPI: delay enumeration of devices with a _DEP pointing to IVSC device

[Wentong Wu]

Inside IVSC, switching ownership requires an interface with two
different hardware modules, ACE and CSI. The software interface
to these modules is based on Intel MEI framework. Usually mei
client devices are dynamically created, so the info of consumers
depending on mei client devices is not present in the firmware
tables.

This causes problems with the probe ordering with respect to
drivers for consumers of these mei client devices. But on these
camera sensor devices, the ACPI nodes describing the sensors all
have a _DEP dependency on the matching mei bus ACPI device, so
adding IVSC mei bus ACPI device to acpi_honor_dep_ids allows
solving the probe-ordering problem by delaying the enumeration of
ACPI-devices which have a _DEP dependency on an IVSC mei bus ACPI
device.

On TGL platform, the HID of IVSC mei bus ACPI device is INTC1059,
and on ADL platform, the HID is INTC1095. So add both of them to
acpi_honor_dep_ids.

Signed-off-by: Wentong Wu <wentong.wu@intel.com>
---
 drivers/acpi/scan.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 2743444..04560e8 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -796,6 +796,8 @@ static const char * const acpi_ignore_dep_ids[] = {
 /* List of HIDs for which we honor deps of matching ACPI devs, when checking _DEP lists. */
 static const char * const acpi_honor_dep_ids[] = {
 	"INT3472", /* Camera sensor PMIC / clk and regulator info */
+	"INTC1059", /* IVSC (TGL) driver must be loaded to allow i2c access to camera sensors */
+	"INTC1095", /* IVSC (ADL) driver must be loaded to allow i2c access to camera sensors */
 	NULL
 };
 
-- 
2.7.4