[Y2038] [PATCH v4 06/10] cec: add HDMI CEC framework: y2038 question
Hans Verkuil
hverkuil at xs4all.nl
Mon May 4 00:42:36 PDT 2015
Ping! (Added Arnd to the CC list)
On 04/27/2015 09:40 AM, Hans Verkuil wrote:
> Added the y2038 mailinglist since I would like to get their input for
> this API.
>
> Y2038 experts, can you take a look at my comment in the code below?
>
> Thanks!
Arnd, I just saw your patch series adding struct __kernel_timespec to
uapi/linux/time.h. I get the feeling that it might take a few kernel
cycles before we have a timespec64 available in userspace. Based on that
I think this CEC API should drop the timestamps for now and wait until
timespec64 becomes available before adding it.
The timestamps are a nice-to-have, but not critical. So adding it later
shouldn't be a problem. What is your opinion?
Hans
>
> On 04/23/2015 03:03 PM, Kamil Debski wrote:
>> From: Hans Verkuil <hansverk at cisco.com>
>>
>> The added HDMI CEC framework provides a generic kernel interface for
>> HDMI CEC devices.
>>
>> Signed-off-by: Hans Verkuil <hansverk at cisco.com>
>> [k.debski at samsung.com: Merged CEC Updates commit by Hans Verkuil]
>> [k.debski at samsung.com: Merged Update author commit by Hans Verkuil]
>> [k.debski at samsung.com: change kthread handling when setting logical
>> address]
>> [k.debski at samsung.com: code cleanup and fixes]
>> [k.debski at samsung.com: add missing CEC commands to match spec]
>> [k.debski at samsung.com: add RC framework support]
>> [k.debski at samsung.com: move and edit documentation]
>> [k.debski at samsung.com: add vendor id reporting]
>> [k.debski at samsung.com: add possibility to clear assigned logical
>> addresses]
>> [k.debski at samsung.com: documentation fixes, clenaup and expansion]
>> [k.debski at samsung.com: reorder of API structs and add reserved fields]
>> [k.debski at samsung.com: fix handling of events and fix 32/64bit timespec
>> problem]
>> [k.debski at samsung.com: add cec.h to include/uapi/linux/Kbuild]
>> Signed-off-by: Kamil Debski <k.debski at samsung.com>
>> ---
>> Documentation/cec.txt | 396 ++++++++++++++++
>> drivers/media/Kconfig | 6 +
>> drivers/media/Makefile | 2 +
>> drivers/media/cec.c | 1161 +++++++++++++++++++++++++++++++++++++++++++++
>> include/media/cec.h | 140 ++++++
>> include/uapi/linux/Kbuild | 1 +
>> include/uapi/linux/cec.h | 303 ++++++++++++
>> 7 files changed, 2009 insertions(+)
>> create mode 100644 Documentation/cec.txt
>> create mode 100644 drivers/media/cec.c
>> create mode 100644 include/media/cec.h
>> create mode 100644 include/uapi/linux/cec.h
>>
>
> <snip>
>
>> diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild
>> index 4842a98..5854cfd 100644
>> --- a/include/uapi/linux/Kbuild
>> +++ b/include/uapi/linux/Kbuild
>> @@ -81,6 +81,7 @@ header-y += capi.h
>> header-y += cciss_defs.h
>> header-y += cciss_ioctl.h
>> header-y += cdrom.h
>> +header-y += cec.h
>> header-y += cgroupstats.h
>> header-y += chio.h
>> header-y += cm4000_cs.h
>> diff --git a/include/uapi/linux/cec.h b/include/uapi/linux/cec.h
>> new file mode 100644
>> index 0000000..bb6d66c
>> --- /dev/null
>> +++ b/include/uapi/linux/cec.h
>> @@ -0,0 +1,303 @@
>> +#ifndef _CEC_H
>> +#define _CEC_H
>> +
>> +#include <linux/types.h>
>> +
>> +struct cec_time {
>> + __u64 sec;
>> + __u64 nsec;
>> +};
>
> I don't like having to introduce a new struct for time here. Basically we are
> only doing this because there is still no public struct timespec64.
>
> When will that struct become available for use in a public API? If it is 4.2,
> then we can start using it. If it will take longer, then what alternative can
> we use to prevent having to change the API later?
>
> One alternative might be to drop it for now and just reserve space in the
> structs to add it later.
>
> Input from the y2038 experts will be welcome!
>
> Regards,
>
> Hans
>
>> +
>> +struct cec_msg {
>> + struct cec_time ts;
>> + __u32 len;
>> + __u32 status;
>> + __u32 timeout;
>> + /* timeout (in ms) is used to timeout CEC_RECEIVE.
>> + Set to 0 if you want to wait forever. */
>> + __u8 msg[16];
>> + __u8 reply;
>> + /* If non-zero, then wait for a reply with this opcode.
>> + If there was an error when sending the msg or FeatureAbort
>> + was returned, then reply is set to 0.
>> + If reply is non-zero upon return, then len/msg are set to
>> + the received message.
>> + If reply is zero upon return and status has the
>> + CEC_TX_STATUS_FEATURE_ABORT bit set, then len/msg are set to the
>> + received feature abort message.
>> + If reply is zero upon return and status has the
>> + CEC_TX_STATUS_REPLY_TIMEOUT
>> + bit set, then no reply was seen at all.
>> + This field is ignored with CEC_RECEIVE.
>> + If reply is non-zero for CEC_TRANSMIT and the message is a broadcast,
>> + then -EINVAL is returned.
>> + if reply is non-zero, then timeout is set to 1000 (the required
>> + maximum response time).
>> + */
>> + __u8 reserved[31];
>> +};
>> +
>> +static inline __u8 cec_msg_initiator(const struct cec_msg *msg)
>> +{
>> + return msg->msg[0] >> 4;
>> +}
>> +
>> +static inline __u8 cec_msg_destination(const struct cec_msg *msg)
>> +{
>> + return msg->msg[0] & 0xf;
>> +}
>> +
>> +static inline bool cec_msg_is_broadcast(const struct cec_msg *msg)
>> +{
>> + return (msg->msg[0] & 0xf) == 0xf;
>> +}
>> +
>> +/* cec status field */
>> +#define CEC_TX_STATUS_OK (0)
>> +#define CEC_TX_STATUS_ARB_LOST (1 << 0)
>> +#define CEC_TX_STATUS_RETRY_TIMEOUT (1 << 1)
>> +#define CEC_TX_STATUS_FEATURE_ABORT (1 << 2)
>> +#define CEC_TX_STATUS_REPLY_TIMEOUT (1 << 3)
>> +#define CEC_RX_STATUS_READY (0)
>> +
>> +#define CEC_LOG_ADDR_INVALID 0xff
>> +
>> +/* The maximum number of logical addresses one device can be assigned to.
>> + * The CEC 2.0 spec allows for only 2 logical addresses at the moment. The
>> + * Analog Devices CEC hardware supports 3. So let's go wild and go for 4. */
>> +#define CEC_MAX_LOG_ADDRS 4
>> +
>> +/* The "Primary Device Type" */
>> +#define CEC_PRIM_DEVTYPE_TV 0
>> +#define CEC_PRIM_DEVTYPE_RECORD 1
>> +#define CEC_PRIM_DEVTYPE_TUNER 3
>> +#define CEC_PRIM_DEVTYPE_PLAYBACK 4
>> +#define CEC_PRIM_DEVTYPE_AUDIOSYSTEM 5
>> +#define CEC_PRIM_DEVTYPE_SWITCH 6
>> +#define CEC_PRIM_DEVTYPE_VIDEOPROC 7
>> +
>> +/* The "All Device Types" flags (CEC 2.0) */
>> +#define CEC_FL_ALL_DEVTYPE_TV (1 << 7)
>> +#define CEC_FL_ALL_DEVTYPE_RECORD (1 << 6)
>> +#define CEC_FL_ALL_DEVTYPE_TUNER (1 << 5)
>> +#define CEC_FL_ALL_DEVTYPE_PLAYBACK (1 << 4)
>> +#define CEC_FL_ALL_DEVTYPE_AUDIOSYSTEM (1 << 3)
>> +#define CEC_FL_ALL_DEVTYPE_SWITCH (1 << 2)
>> +/* And if you wondering what happened to VIDEOPROC devices: those should
>> + * be mapped to a SWITCH. */
>> +
>> +/* The logical address types that the CEC device wants to claim */
>> +#define CEC_LOG_ADDR_TYPE_TV 0
>> +#define CEC_LOG_ADDR_TYPE_RECORD 1
>> +#define CEC_LOG_ADDR_TYPE_TUNER 2
>> +#define CEC_LOG_ADDR_TYPE_PLAYBACK 3
>> +#define CEC_LOG_ADDR_TYPE_AUDIOSYSTEM 4
>> +#define CEC_LOG_ADDR_TYPE_SPECIFIC 5
>> +#define CEC_LOG_ADDR_TYPE_UNREGISTERED 6
>> +/* Switches should use UNREGISTERED.
>> + * Video processors should use SPECIFIC. */
>> +
>> +/* The CEC version */
>> +#define CEC_VERSION_1_4B 5
>> +#define CEC_VERSION_2_0 6
>> +
>> +struct cec_event {
>> + struct cec_time ts;
>> + __u32 event;
>> + __u8 reserved[4];
>> +};
>> +
>> +/* The CEC state */
>> +#define CEC_STATE_DISABLED 0
>> +#define CEC_STATE_ENABLED 1
>> +
>> +/* Userspace has to configure the adapter state (enable/disable) */
>> +#define CEC_CAP_STATE (1 << 0)
>> +/* Userspace has to configure the physical address */
>> +#define CEC_CAP_PHYS_ADDR (1 << 1)
>> +/* Userspace has to configure the logical addresses */
>> +#define CEC_CAP_LOG_ADDRS (1 << 2)
>> +/* Userspace can transmit messages */
>> +#define CEC_CAP_TRANSMIT (1 << 3)
>> +/* Userspace can receive messages */
>> +#define CEC_CAP_RECEIVE (1 << 4)
>> +/* Userspace has to configure the vendor id */
>> +#define CEC_CAP_VENDOR_ID (1 << 5)
>> +/* The hardware has the possibility to work in the promiscuous mode */
>> +#define CEC_CAP_PROMISCUOUS (1 << 6)
>> +
>> +struct cec_caps {
>> + __u32 available_log_addrs;
>> + __u32 capabilities;
>> + __u32 vendor_id;
>> + __u8 version;
>> + __u8 reserved[11];
>> +};
>> +
>> +struct cec_log_addrs {
>> + __u8 cec_version;
>> + __u8 num_log_addrs;
>> + __u8 primary_device_type[CEC_MAX_LOG_ADDRS];
>> + __u8 log_addr_type[CEC_MAX_LOG_ADDRS];
>> + __u8 log_addr[CEC_MAX_LOG_ADDRS];
>> +
>> + /* CEC 2.0 */
>> + __u8 all_device_types;
>> + __u8 features[CEC_MAX_LOG_ADDRS][12];
>> +
>> + __u8 reserved[9];
>> +};
>> +
>> +/* Commands */
>> +
>> +/* One Touch Play Feature */
>> +#define CEC_OP_ACTIVE_SOURCE 0x82
>> +#define CEC_OP_IMAGE_VIEW_ON 0x04
>> +#define CEC_OP_TEXT_VIEW_ON 0x0d
>> +
>> +/* Routing Control Feature */
>> +#define CEC_OP_ACTIVE_SOURCE 0x82
>> +#define CEC_OP_INACTIVE_SOURCE 0x9d
>> +#define CEC_OP_REQUEST_ACTIVE_SOURCE 0x85
>> +#define CEC_OP_ROUTING_CHANGE 0x80
>> +#define CEC_OP_ROUTING_INFORMATION 0x81
>> +#define CEC_OP_SET_STREAM_PATH 0x86
>> +
>> +/* Standby Feature */
>> +#define CEC_OP_STANDBY 0x36
>> +
>> +/* One Touch Record Feature */
>> +#define CEC_OP_RECORD_OFF 0x0b
>> +#define CEC_OP_RECORD_ON 0x09
>> +#define CEC_OP_RECORD_STATUS 0x0a
>> +#define CEC_OP_RECORD_TV_SCREEN 0x0f
>> +
>> +/* Timer Programming Feature */
>> +#define CEC_OP_CLEAR_ANALOGUE_TIMER 0x33
>> +#define CEC_OP_CLEAR_DIGITAL_TIMER 0x99
>> +#define CEC_OP_CLEAR_EXT_TIMER 0xa1
>> +#define CEC_OP_SET_ANALOGUE_TIMER 0x34
>> +#define CEC_OP_SET_DIGITAL_TIMER 0x97
>> +#define CEC_OP_SET_EXT_TIMER 0xa2
>> +#define CEC_OP_SET_EXT_PROGRAM_TIMER 0x67
>> +#define CEC_OP_TIMER_CLEARED_STATUS 0x43
>> +#define CEC_OP_TIMER_STATUS 0x35
>> +
>> +/* System Information Feature */
>> +#define CEC_OP_CEC_VERSION 0x9e
>> +#define CEC_OP_GET_CEC_VERSION 0x9f
>> +#define CEC_OP_GIVE_PHYSICAL_ADDR 0x83
>> +#define CEC_OP_GET_MENU_LANGUAGE 0x91
>> +#define CEC_OP_REPORT_PHYSICAL_ADDR 0x84
>> +#define CEC_OP_SET_MENU_LANGUAGE 0x32
>> +
>> +/* Deck Control Feature */
>> +#define CEC_OP_DECK_CONTROL 0x42
>> +#define CEC_OP_DECK_STATUS 0x1b
>> +#define CEC_OP_GIVE_DECK_STATUS 0x1a
>> +#define CEC_OP_PLAY 0x41
>> +
>> +/* Tuner Control Feature */
>> +#define CEC_OP_GIVE_TUNER_DEVICE_STATUS 0x08
>> +#define CEC_OP_SELECT_ANALOGUE_SERVICE 0x92
>> +#define CEC_OP_SELECT_DIGITAL_SERVICE 0x93
>> +#define CEC_OP_TUNER_DEVICE_STATUS 0x07
>> +#define CEC_OP_TUNER_STEP_DECREMENT 0x06
>> +#define CEC_OP_TUNER_STEP_INCREMENT 0x05
>> +
>> +/* Vendor Specific Commands Feature */
>> +#define CEC_OP_CEC_VERSION 0x9e
>> +#define CEC_OP_DEVICE_VENDOR_ID 0x87
>> +#define CEC_OP_GET_CEC_VERSION 0x9f
>> +#define CEC_OP_GIVE_DEVICE_VENDOR_ID 0x8c
>> +#define CEC_OP_VENDOR_COMMAND 0x89
>> +#define CEC_OP_VENDOR_COMMAND_WITH_ID 0xa0
>> +#define CEC_OP_VENDOR_REMOTE_BUTTON_DOWN 0x8a
>> +#define CEC_OP_VENDOR_REMOTE_BUTTON_UP 0x8b
>> +
>> +/* OSD Display Feature */
>> +#define CEC_OP_SET_OSD_STRING 0x64
>> +
>> +/* Device OSD Transfer Feature */
>> +#define CEC_OP_GIVE_OSD_NAME 0x46
>> +#define CEC_OP_SET_OSD_NAME 0x47
>> +
>> +/* Device Menu Control Feature */
>> +#define CEC_OP_MENU_REQUEST 0x8d
>> +#define CEC_OP_MENU_STATUS 0x8e
>> +#define CEC_OP_USER_CONTROL_PRESSED 0x44
>> +#define CEC_OP_USER_CONTROL_RELEASED 0x45
>> +
>> +/* Power Status Feature */
>> +#define CEC_OP_GIVE_DEVICE_POWER_STATUS 0x8f
>> +#define CEC_OP_REPORT_POWER_STATUS 0x90
>> +#define CEC_OP_FEATURE_ABORT 0x00
>> +#define CEC_OP_ABORT 0xff
>> +
>> +/* System Audio Control Feature */
>> +#define CEC_OP_GIVE_AUDIO_STATUS 0x71
>> +#define CEC_OP_GIVE_SYSTEM_AUDIO_MODE_STATUS 0x7d
>> +#define CEC_OP_REPORT_AUDIO_STATUS 0x7a
>> +#define CEC_OP_SET_SYSTEM_AUDIO_MODE 0x72
>> +#define CEC_OP_SYSTEM_AUDIO_MODE_REQUEST 0x70
>> +#define CEC_OP_SYSTEM_AUDIO_MODE_STATUS 0x7e
>> +
>> +/* Audio Rate Control Feature */
>> +#define CEC_OP_SET_AUDIO_RATE 0x9a
>> +
>> +/* Events */
>> +/* Event that occurs when a cable is connected */
>> +#define CEC_EVENT_CONNECT 1
>> +/* Event that occurs when all logical addresses were claimed */
>> +#define CEC_EVENT_READY 2
>> +/* Event that is sent when the cable is disconnected */
>> +#define CEC_EVENT_DISCONNECT 3
>> +
>> +/* ioctls */
>> +
>> +/* issue a CEC command */
>> +#define CEC_G_CAPS _IOWR('a', 0, struct cec_caps)
>> +#define CEC_TRANSMIT _IOWR('a', 1, struct cec_msg)
>> +#define CEC_RECEIVE _IOWR('a', 2, struct cec_msg)
>> +
>> +/*
>> + Configure the CEC adapter. It sets the device type and which
>> + logical types it will try to claim. It will return which
>> + logical addresses it could actually claim.
>> + An error is returned if the adapter is disabled or if there
>> + is no physical address assigned.
>> + */
>> +
>> +#define CEC_G_ADAP_LOG_ADDRS _IOR('a', 3, struct cec_log_addrs)
>> +#define CEC_S_ADAP_LOG_ADDRS _IOWR('a', 4, struct cec_log_addrs)
>> +
>> +/*
>> + Enable/disable the adapter. The Set state ioctl may not
>> + be available if that is handled internally.
>> + */
>> +#define CEC_G_ADAP_STATE _IOR('a', 5, __u32)
>> +#define CEC_S_ADAP_STATE _IOW('a', 6, __u32)
>> +
>> +/*
>> + phys_addr is either 0 (if this is the CEC root device)
>> + or a valid physical address obtained from the sink's EDID
>> + as read by this CEC device (if this is a source device)
>> + or a physical address obtained and modified from a sink
>> + EDID and used for a sink CEC device.
>> + If nothing is connected, then phys_addr is 0xffff.
>> + See HDMI 1.4b, section 8.7 (Physical Address).
>> +
>> + The Set ioctl may not be available if that is handled
>> + internally.
>> + */
>> +#define CEC_G_ADAP_PHYS_ADDR _IOR('a', 7, __u16)
>> +#define CEC_S_ADAP_PHYS_ADDR _IOW('a', 8, __u16)
>> +
>> +#define CEC_G_EVENT _IOWR('a', 9, struct cec_event)
>> +/*
>> + Read and set the vendor ID of the CEC adapter.
>> + */
>> +#define CEC_G_VENDOR_ID _IOR('a', 9, __u32)
>> +#define CEC_S_VENDOR_ID _IOW('a', 10, __u32)
>> +
>> +#endif
>>
>
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