From patchwork Thu Jul 27 07:15:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bingbu Cao X-Patchwork-Id: 13329033 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D94F0C001E0 for ; Thu, 27 Jul 2023 07:12:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233200AbjG0HMv (ORCPT ); Thu, 27 Jul 2023 03:12:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233204AbjG0HMa (ORCPT ); Thu, 27 Jul 2023 03:12:30 -0400 Received: from mgamail.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A81D84211 for ; Thu, 27 Jul 2023 00:07:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1690441629; x=1721977629; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=c3wrTsVpPtHIzNRvSjgXT1JgoxxvSHSVSSGbdlHSo6c=; b=mbwJCX68LD96/9kmwTff5LERhQR3PzxE1a0KwE4FxEV0LOXCY35QWqpx mYrg/dePovLNjjCpE5Ue7bSxoj0uB9LneNg8wemtGhvajMfBb/lkinoJZ GGdd9ZPVuPXacV+DF+0zPMhYE3bBW12CICL9vVlDY+NCyg7mLQtLDKqmt wgCDoOGkqCITzuOnZNFx7jitbJ/g69AZNZNMGBps43kCoMgexvsS2YSfP yOt5nHnc5gqEMkq/syyLkxp2AlOrtwLm5y+kTjIrabAv7wnUlkiEp+yDM 8YM1L2YmrAEeABYvW18qPQHjoO4hueojcoVwVmG6UsesTQ1AIL1cv4FST w==; X-IronPort-AV: E=McAfee;i="6600,9927,10783"; a="370901057" X-IronPort-AV: E=Sophos;i="6.01,234,1684825200"; d="scan'208";a="370901057" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jul 2023 00:05:13 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10783"; a="704073397" X-IronPort-AV: E=Sophos;i="6.01,234,1684825200"; d="scan'208";a="704073397" Received: from icg-kernel3.bj.intel.com ([172.16.126.100]) by orsmga006.jf.intel.com with ESMTP; 27 Jul 2023 00:05:09 -0700 From: bingbu.cao@intel.com To: linux-media@vger.kernel.org, sakari.ailus@linux.intel.com, laurent.pinchart@ideasonboard.com Cc: ilpo.jarvinen@linux.intel.com, tfiga@chromium.org, senozhatsky@chromium.org, andriy.shevchenko@linux.intel.com, hdegoede@redhat.com, tomi.valkeinen@ideasonboard.com, bingbu.cao@intel.com, bingbu.cao@linux.intel.com, tian.shu.qiu@intel.com, hongju.wang@intel.com Subject: [PATCH 15/15] Documentation: add documentation of Intel IPU6 driver and hardware overview Date: Thu, 27 Jul 2023 15:15:58 +0800 Message-Id: <20230727071558.1148653-16-bingbu.cao@intel.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230727071558.1148653-1-bingbu.cao@intel.com> References: <20230727071558.1148653-1-bingbu.cao@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org From: Bingbu Cao Add a documentation for an overview of IPU6 hardware and describe the main the components of IPU6 driver. Signed-off-by: Bingbu Cao --- .../driver-api/media/drivers/index.rst | 1 + .../driver-api/media/drivers/ipu6.rst | 205 ++++++++++++++++++ 2 files changed, 206 insertions(+) create mode 100644 Documentation/driver-api/media/drivers/ipu6.rst diff --git a/Documentation/driver-api/media/drivers/index.rst b/Documentation/driver-api/media/drivers/index.rst index c4123a16b5f9..7f6f3dcd5c90 100644 --- a/Documentation/driver-api/media/drivers/index.rst +++ b/Documentation/driver-api/media/drivers/index.rst @@ -26,6 +26,7 @@ Video4Linux (V4L) drivers vimc-devel zoran ccs/ccs + ipu6 Digital TV drivers diff --git a/Documentation/driver-api/media/drivers/ipu6.rst b/Documentation/driver-api/media/drivers/ipu6.rst new file mode 100644 index 000000000000..2685e4a0d7ba --- /dev/null +++ b/Documentation/driver-api/media/drivers/ipu6.rst @@ -0,0 +1,205 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================== +Intel IPU6 Driver +================== + +Author: Bingbu Cao + +Overview +========= + +Intel IPU6 is the sixth generation of Intel Image Processing Unit used in some +Intel Chipsets such as Tiger Lake, Jasper Lake, Alder Lake, Raptor Lake and +Meteor Lake. IPU6 consists of two major systems - Input System (IS) and +Processing System (PS). IPU6 are visible on the PCI bus as a single device, +it can be found by ``lspci``: + +``0000:00:05.0 Multimedia controller: Intel Corporation Device xxxx (rev xx)`` + +IPU6 has a 16 MB BAR in PCI configuration Space for MMIO registers which is +visible for driver. + +Buttress +========= + +The IPU6 is connecting to the system fabric with ``Buttress`` which is enabling +host driver to control the IPU6, it also allows IPU6 access the system memory to +store and load frame pixel streams and any other metadata. + +``Buttress`` mainly manages several system functionalities - power management, +interrupt handling, firmware authentication and global timer sync. + +IS and PS Power flow +--------------------------- + +IPU6 driver initialize the IS and PS power up or down request by setting the +Buttress frequency control register for IS and PS - +``IPU6_BUTTRESS_REG_IS_FREQ_CTL`` and ``IPU6_BUTTRESS_REG_PS_FREQ_CTL`` in +function: + +.. c:function:: int ipu6_buttress_power(..., bool on) + +Buttress forwards the request to Punit, after Punit execute the power up flow, +buttress indicates driver that IS or PS is powered up by updating the power +status registers. + +.. Note:: IS power up needs take place prior to PS power up, IS power down needs + take place after PS power down due to hardware limitation. + + +Interrupt +------------ + +IPU6 interrupt can be generated as MSI or INTA, interrupt will be triggered +when IS, PS, Buttress event or error happen, driver can get the interrupt +cause by reading the interrupt status register ``BUTTRESS_REG_ISR_STATUS``, +driver firstly clear the irq status and then call specific IS or PS irq handler. + +.. c:function:: irqreturn_t ipu6_buttress_isr(int irq, ...) + +Security and firmware authentication +------------------------------------- +To address the IPU6 firmware security concerns, the IPU6 firmware needs to +undergo an authentication process before it is allowed to executed on the IPU6 +internal processors. Driver will work with Converged Security Engine (CSE) to +complete authentication process. CSE is responsible of authenticating the +IPU6 firmware, the authenticated firmware binary is copied into an isolated +memory region. Firmware authentication process is implemented by CSE following +an IPC handshake with driver. There are some Buttress registers used by CSE and +driver to communicate with each other as IPC messages. + +.. c:function:: int ipu6_buttress_authenticate(...) + +Global timer sync +------------------ +IPU driver initiates a Hammock Harbor synchronization flow each time it starts +camera operation. IPU will synchronizes an internal counter in the Buttress +with a copy of SoC time, this counter keeps the updated time until camera +operation is stopped. Driver can use this time counter to calibrate the +timestamp based on the timestamp in response event from firmware. + +.. c:function:: int ipu6_buttress_start_tsc_sync(...) + + +DMA and MMU +============ + +IPU6 has its own scalar processor where the firmware run at, it has +an internal 32-bits virtual address space. IPU6 has MMU address translation +hardware to allow that scalar process access the internal memory and external +system memory through IPU6 virtual address. The address translation is +based on two levels of page lookup tables stored in system memory which are +maintained by IPU6 driver. IPU6 driver sets the level-1 page table base address +to MMU register and allow MMU to lookup the page table. + +IPU6 driver exports its own DMA operations. Driver will update the page table +entries for each DMA operation and invalidate the MMU TLB after each unmap and +free. + +.. code-block:: none + + const struct dma_map_ops ipu6_dma_ops = { + .alloc = ipu6_dma_alloc, + .free = ipu6_dma_free, + .mmap = ipu6_dma_mmap, + .map_sg = ipu6_dma_map_sg, + .unmap_sg = ipu6_dma_unmap_sg, + ... + }; + +.. Note:: IPU6 MMU works behind IOMMU, so for each IPU6 DMA ops, driver will + call generic PCI DMA ops to ask IOMMU to do the additional mapping + if VT-d enabled. + + +Firmware file format +===================== + +IPU6 release the firmware in Code Partition Directory (CPD) file format. The +CPD firmware contains a CPD header, several CPD entries and CPD components. +CPD component includes 3 entries - manifest, metadata and module data. Manifest +and metadata are defined by CSE and used by CSE for authentication. Module data +is defined by IPU6 which holds the binary data of firmware called package +directory. IPU6 driver (``ipu6-cpd.c``) parses and validates the CPD firmware +file and get the package directory binary data of IPU6 firmware, copy it to +specific DMA buffer and sets its base address to Buttress ``FW_SOURCE_BASE`` +register, CSE will do authentication for this firmware binary. + + +Syscom interface +================ + +IPU6 driver communicates with firmware via syscom ABI. Syscom is an +inter-processor communication mechanism between IPU scalar processor and CPU. +There are a number of resources shared between firmware and software. +A system memory region where the message queues reside, firmware can access the +memory region via IPU MMU. Syscom queues are FIFO fixed depth queues with +configurable elements ``token`` (message). There is also a common IPU MMIO +registers where the queue read and write indices reside. Software and firmware +work as producer and consumer of tokens in queue, and update the write and read +indices separately when sending or receiving each message. + +IPU6 driver must prepare and configure the number of input and output queues, +configure the count of tokens per queue and the size of per token before +initiate and start the communication with firmware, firmware and software must +use same configurations. IPU6 Buttress has a number of firmware boot parameter +registers which can be used to store the address of configuration and initiate +the Syscom state, then driver can request firmware to start and run via setting +the scalar processor control status register. + + +Input System +============== + +IPU6 input system consists of MIPI D-PHY and several CSI receiver controllers, +it can capture image pixel data from camera sensors or other MIPI CSI output +devices. + +DPHYs and CSI2 ports lane mapping +--------------------------------- + +IPU6 integrates different D-PHY IPs on different SoCs, on Tiger Lake and Alder +Lake, IPU6 integrates MCD10 D-PHY, IPU6SE on Jasper Lake integrates JSL D-PHY +and IPU6EP on Meteor Lake integrates a Synopsys DWC D-PHY. There is an adaption +layer between D-PHY and CSI receiver controller which includes port +configuration, PHY wrapper or private test interfaces for D-PHY. There are 3 +D-PHY drivers ``ipu6-isys-mcd-phy.c``, ``ipu6-isys-jsl-phy.c`` and +``ipu6-isys-dwc-phy.c`` program the above 3 D-PHYs in IPU6. + +Different IPU6 version has different DPHY lanes mappings, On Tiger Lake, there +are 12 data lanes and 8 clock lanes, IPU6 support maximum 8 CSI2 ports, see +the ppi mmapping in ``ipu6-isys-mcd-phy.c`` for more information. On Jasper Lake +and Alder Lake, DPHY has 8 data lanes and 4 clock lanes, IPU6 support maximum 4 +CSI2 ports. For Meteor Lake, DPHY has 12 data lanes and 6 clock lanes, IPU6 +support maximum 6 CSI2 ports. + +.. Note:: Each adjacent CSI ports work as a pair and share the data lanes. + For example, for CSI port 0 and 1, CSI port 0 support maximum 4 + data lanes, CSI port 1 support maximum 2 data lanes, CSI port 0 + with 2 data lanes can work together with CSI port 1 with 2 data lanes. + If trying to use CSI port 0 with 4 lanes, CSI port 1 will not be + available as the 4 data lanes are shared by CSI port 0 and 1. Same + scenario is also applied for CSI port 2/3, 4/5 and 7/8. + +IS firmware ABIs +---------------- + +IPU6 firmware define a series of ABIs to software. In general, software firstly +prepare the stream configuration ``struct ipu6_fw_isys_stream_cfg_data_abi`` +and send the configuration to firmware via sending ``STREAM_OPEN`` command. +Stream configuration includes input pins and output pins, input pin +``struct ipu6_fw_isys_input_pin_info_abi`` defines the resolution and data type +of input source, output pin ``struct ipu6_fw_isys_output_pin_info_abi`` +defines the output resolution, stride and frame format, etc. Once driver get the +interrupt from firmware that indicates stream open successfully, driver will +send the ``STREAM_START`` and ``STREAM_CAPTURE`` command to request firmware to +start capturing image frames. ``STREAM_CAPTURE`` command queues the buffers to +firmware with ``struct ipu6_fw_isys_frame_buff_set``, software then wait the +interrupt and response from firmware, ``PIN_DATA_READY`` means data ready +on specific output pin and then software return the buffers to user. + +.. Note:: See Documentation/admin-guide/media/ipu6-isys.rst for how to do + capture by IPU6 IS driver. + +