github.com/ethanhsieh/snapd@v0.0.0-20210615102523-3db9b8e4edc5/interfaces/builtin/dsp.go (about)

     1  // -*- Mode: Go; indent-tabs-mode: t -*-
     2  
     3  /*
     4   * Copyright (C) 2021 Canonical Ltd
     5   *
     6   * This program is free software: you can redistribute it and/or modify
     7   * it under the terms of the GNU General Public License version 3 as
     8   * published by the Free Software Foundation.
     9   *
    10   * This program is distributed in the hope that it will be useful,
    11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13   * GNU General Public License for more details.
    14   *
    15   * You should have received a copy of the GNU General Public License
    16   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    17   *
    18   */
    19  
    20  package builtin
    21  
    22  import (
    23  	"github.com/snapcore/snapd/interfaces"
    24  	"github.com/snapcore/snapd/interfaces/apparmor"
    25  	"github.com/snapcore/snapd/interfaces/udev"
    26  )
    27  
    28  const dspSummary = `allows controlling digital signal processors on certain boards`
    29  
    30  const dspBaseDeclarationSlots = `
    31    dsp:
    32      allow-installation:
    33        slot-snap-type:
    34          - gadget
    35          - core
    36      deny-auto-connection: true
    37  `
    38  
    39  const ambarellaDspConnectedPlugApparmor = `
    40  # Description: can manage and control the integrated digital signal processor on
    41  # the ambarella device. This allows privileged access to hardware and kernel 
    42  # drivers related to the digital signal processor and thus is only allowed on
    43  # specific devices providing the slot via a gadget and is also not auto-
    44  # connected.
    45  
    46  # The ucode device node corresponds to the firmware on the digital signal 
    47  # processor
    48  /dev/ucode rw,
    49  
    50  # The iav device node is the device node exposed for the specific IAV linux
    51  # device driver used with the CV2x / S6Lm cores on an ambarella device
    52  /dev/iav rw,
    53  
    54  # The cavalry device node is used for managing the CV2x vector processor (VP).
    55  /dev/cavalry rw,
    56  
    57  # another DSP device node
    58  /dev/lens rw,
    59  
    60  # also needed for interfacing with the DSP
    61  /proc/ambarella/vin0_idsp rw,
    62  `
    63  
    64  var ambarellaDspConnectedPlugUDev = []string{
    65  	`KERNEL=="iav"`,
    66  	`KERNEL=="cavalry"`,
    67  	`KERNEL=="ucode"`,
    68  	`KERNEL=="lens"`,
    69  }
    70  
    71  type dspInterface struct {
    72  	commonInterface
    73  }
    74  
    75  func (iface *dspInterface) AppArmorConnectedPlug(spec *apparmor.Specification, plug *interfaces.ConnectedPlug, slot *interfaces.ConnectedSlot) error {
    76  	// check the flavor of the slot
    77  
    78  	var flavor string
    79  	_ = slot.Attr("flavor", &flavor)
    80  	switch flavor {
    81  	// only supported flavor for now
    82  	case "ambarella":
    83  		spec.AddSnippet(ambarellaDspConnectedPlugApparmor)
    84  	}
    85  
    86  	return nil
    87  }
    88  
    89  func (iface *dspInterface) UDevConnectedPlug(spec *udev.Specification, plug *interfaces.ConnectedPlug, slot *interfaces.ConnectedSlot) error {
    90  	// check the flavor of the slot
    91  	var flavor string
    92  	_ = slot.Attr("flavor", &flavor)
    93  	switch flavor {
    94  	// only supported flavor for now
    95  	case "ambarella":
    96  		for _, rule := range ambarellaDspConnectedPlugUDev {
    97  			spec.TagDevice(rule)
    98  		}
    99  	}
   100  
   101  	return nil
   102  }
   103  
   104  func init() {
   105  	registerIface(&dspInterface{commonInterface{
   106  		name:                 "dsp",
   107  		summary:              dspSummary,
   108  		baseDeclarationSlots: dspBaseDeclarationSlots,
   109  	}})
   110  }