Hi Wentong,
On Mon, Mar 27, 2023 at 02:23:07PM +0800, Wentong Wu wrote:
> 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@xxxxxxxxx>
> ---
> drivers/media/pci/intel/ivsc/Makefile | 3 +
> drivers/media/pci/intel/ivsc/mei_ace.c | 534 +++++++++++++++++++++++++++++++++
> 2 files changed, 537 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 7e4c5f0..a641f14 100644
> --- a/drivers/media/pci/intel/ivsc/Makefile
> +++ b/drivers/media/pci/intel/ivsc/Makefile
> @@ -5,3 +5,6 @@
> obj-$(CONFIG_INTEL_VSC) += ivsc-csi.o
> ivsc-csi-y += mei_csi.o
> ivsc-csi-y += csi_bridge.o
> +
> +obj-$(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..434b072
> --- /dev/null
> +++ b/drivers/media/pci/intel/ivsc/mei_ace.c
> @@ -0,0 +1,534 @@
> +// 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.
Could you document the dependencies in the sensor initialisation (ace +
csi) and how the sensor is powered (i.e. no direct control of the PMIC from
the host?)? This doesn't seem like a bad place to do it.
> + */
> +
> +#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 UUID_LE(0x6167DCFB, 0x72F1, 0x4584, 0xBF, \
> + 0xE3, 0x84, 0x17, 0x71, 0xAA, 0x79, 0x0B)
> +
> +/* UUID used to get csi device */
> +#define MEI_CSI_UUID UUID_LE(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 {
> + uuid_le 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 ace */
> + struct mutex lock;
> +
> + /* used to construct command */
> + u16 firmware_id;
> +
> + /* 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 a command to firmware and mutex must be held by caller */
> +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;
> +
> + 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:
> + 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;
> +
> + mutex_lock(&ace->lock);
> +
> + cmd_size = construct_command(ace, &cmd, cmd_id);
There doesn't seem to be a need to take the lock during
construct_command(). Maybe just during mei_ace_send()? You could also
acquire and release the lock there I guess.
> + if (cmd_size >= 0)
> + ret = mei_ace_send(ace, &cmd, cmd_size, false);
> + else
> + ret = cmd_size;
> + mutex_unlock(&ace->lock);
> +
> + 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;
> + uuid_le uuid = MEI_CSI_UUID;
> + struct acpi_device *adev;
> + struct device *csi_dev;
> + char name[64];
> +
> + sprintf(name, "%s-%pUl", dev_name(dev->parent), &uuid);
snprintf(), please.
> + csi_dev = device_find_child_by_name(dev->parent, name);
> + if (!csi_dev)
> + return -EPROBE_DEFER;
> +
> + /* sensor's ACPI _DEP is mei bus device */
> + adev = acpi_dev_get_next_consumer_dev(ACPI_COMPANION(dev->parent), NULL);
Nice.
Please also run this on the patchset:
./scripts/checkpatch.pl --strict --max-line-length=80
> + if (!adev)
> + return -EPROBE_DEFER;
> +
> + /* 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);
> +
> + /* setup link between mei_ace and sensor */
> + ace->sensor_link = device_link_add(&adev->dev, dev,
> + DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE);
device_link_add() may fail.
> +
> + return 0;
> +}
> +
> +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;
> + }
> +
> + pm_runtime_set_active(dev);
> + pm_runtime_enable(dev);
> +
> + 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);
> +
> + 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);
> +
> + pm_runtime_disable(&cldev->dev);
> + pm_runtime_set_suspended(&cldev->dev);
> +
> + 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 UUID_LE(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 },
> +
> + /* required last entry */
> + { }
> +};
> +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@xxxxxxxxx>");
> +MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@xxxxxxxxx>");
> +MODULE_DESCRIPTION("Device driver for IVSC ACE");
> +MODULE_LICENSE("GPL");
--
Kind regards,
Sakari Ailus
