[PATCH v2 08/22] media: docs: split development info from cx88.rst

From: Mauro Carvalho Chehab
Date: Tue Mar 10 2020 - 09:44:48 EST


This file contains both admin and development stuff. Split on
two, as they're usually read by different audiences.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
---
.../media/v4l-drivers/cx88-devel.rst | 113 ++++++++++++++++++
Documentation/media/v4l-drivers/cx88.rst | 107 -----------------
Documentation/media/v4l-drivers/index.rst | 1 +
3 files changed, 114 insertions(+), 107 deletions(-)
create mode 100644 Documentation/media/v4l-drivers/cx88-devel.rst

diff --git a/Documentation/media/v4l-drivers/cx88-devel.rst b/Documentation/media/v4l-drivers/cx88-devel.rst
new file mode 100644
index 000000000000..cfe7c03f4930
--- /dev/null
+++ b/Documentation/media/v4l-drivers/cx88-devel.rst
@@ -0,0 +1,113 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+The cx88 driver
+===============
+
+Author: Gerd Hoffmann
+
+Documentation missing at the cx88 datasheet
+-------------------------------------------
+
+MO_OUTPUT_FORMAT (0x310164)
+
+.. code-block:: none
+
+ Previous default from DScaler: 0x1c1f0008
+ Digit 8: 31-28
+ 28: PREVREMOD = 1
+
+ Digit 7: 27-24 (0xc = 12 = b1100 )
+ 27: COMBALT = 1
+ 26: PAL_INV_PHASE
+ (DScaler apparently set this to 1, resulted in sucky picture)
+
+ Digits 6,5: 23-16
+ 25-16: COMB_RANGE = 0x1f [default] (9 bits -> max 512)
+
+ Digit 4: 15-12
+ 15: DISIFX = 0
+ 14: INVCBF = 0
+ 13: DISADAPT = 0
+ 12: NARROWADAPT = 0
+
+ Digit 3: 11-8
+ 11: FORCE2H
+ 10: FORCEREMD
+ 9: NCHROMAEN
+ 8: NREMODEN
+
+ Digit 2: 7-4
+ 7-6: YCORE
+ 5-4: CCORE
+
+ Digit 1: 3-0
+ 3: RANGE = 1
+ 2: HACTEXT
+ 1: HSFMT
+
+0x47 is the sync byte for MPEG-2 transport stream packets.
+Datasheet incorrectly states to use 47 decimal. 188 is the length.
+All DVB compliant frontends output packets with this start code.
+
+Hauppauge WinTV cx88 IR information
+-----------------------------------
+
+The controls for the mux are GPIO [0,1] for source, and GPIO 2 for muting.
+
+====== ======== =================================================
+GPIO0 GPIO1
+====== ======== =================================================
+ 0 0 TV Audio
+ 1 0 FM radio
+ 0 1 Line-In
+ 1 1 Mono tuner bypass or CD passthru (tuner specific)
+====== ======== =================================================
+
+GPIO 16(I believe) is tied to the IR port (if present).
+
+
+From the data sheet:
+
+- Register 24'h20004 PCI Interrupt Status
+
+ - bit [18] IR_SMP_INT Set when 32 input samples have been collected over
+ - gpio[16] pin into GP_SAMPLE register.
+
+What's missing from the data sheet:
+
+- Setup 4KHz sampling rate (roughly 2x oversampled; good enough for our RC5
+ compat remote)
+- set register 0x35C050 to 0xa80a80
+- enable sampling
+- set register 0x35C054 to 0x5
+- enable the IRQ bit 18 in the interrupt mask register (and
+ provide for a handler)
+
+GP_SAMPLE register is at 0x35C058
+
+Bits are then right shifted into the GP_SAMPLE register at the specified
+rate; you get an interrupt when a full DWORD is received.
+You need to recover the actual RC5 bits out of the (oversampled) IR sensor
+bits. (Hint: look for the 0/1and 1/0 crossings of the RC5 bi-phase data) An
+actual raw RC5 code will span 2-3 DWORDS, depending on the actual alignment.
+
+I'm pretty sure when no IR signal is present the receiver is always in a
+marking state(1); but stray light, etc can cause intermittent noise values
+as well. Remember, this is a free running sample of the IR receiver state
+over time, so don't assume any sample starts at any particular place.
+
+Additional info
+~~~~~~~~~~~~~~~
+
+This data sheet (google search) seems to have a lovely description of the
+RC5 basics:
+http://www.atmel.com/dyn/resources/prod_documents/doc2817.pdf
+
+This document has more data:
+http://www.nenya.be/beor/electronics/rc5.htm
+
+This document has a how to decode a bi-phase data stream:
+http://www.ee.washington.edu/circuit_archive/text/ir_decode.txt
+
+This document has still more info:
+http://www.xs4all.nl/~sbp/knowledge/ir/rc5.htm
diff --git a/Documentation/media/v4l-drivers/cx88.rst b/Documentation/media/v4l-drivers/cx88.rst
index 698c73ea2e36..e4badb18199d 100644
--- a/Documentation/media/v4l-drivers/cx88.rst
+++ b/Documentation/media/v4l-drivers/cx88.rst
@@ -56,110 +56,3 @@ the driver. What to do then?
trial-and-error using the tuner=<n> insmod option. If you
know which one the card has you can also have a look at the
list in CARDLIST.tuner
-
-Documentation missing at the cx88 datasheet
--------------------------------------------
-
-MO_OUTPUT_FORMAT (0x310164)
-
-.. code-block:: none
-
- Previous default from DScaler: 0x1c1f0008
- Digit 8: 31-28
- 28: PREVREMOD = 1
-
- Digit 7: 27-24 (0xc = 12 = b1100 )
- 27: COMBALT = 1
- 26: PAL_INV_PHASE
- (DScaler apparently set this to 1, resulted in sucky picture)
-
- Digits 6,5: 23-16
- 25-16: COMB_RANGE = 0x1f [default] (9 bits -> max 512)
-
- Digit 4: 15-12
- 15: DISIFX = 0
- 14: INVCBF = 0
- 13: DISADAPT = 0
- 12: NARROWADAPT = 0
-
- Digit 3: 11-8
- 11: FORCE2H
- 10: FORCEREMD
- 9: NCHROMAEN
- 8: NREMODEN
-
- Digit 2: 7-4
- 7-6: YCORE
- 5-4: CCORE
-
- Digit 1: 3-0
- 3: RANGE = 1
- 2: HACTEXT
- 1: HSFMT
-
-0x47 is the sync byte for MPEG-2 transport stream packets.
-Datasheet incorrectly states to use 47 decimal. 188 is the length.
-All DVB compliant frontends output packets with this start code.
-
-Hauppauge WinTV cx88 IR information
------------------------------------
-
-The controls for the mux are GPIO [0,1] for source, and GPIO 2 for muting.
-
-====== ======== =================================================
-GPIO0 GPIO1
-====== ======== =================================================
- 0 0 TV Audio
- 1 0 FM radio
- 0 1 Line-In
- 1 1 Mono tuner bypass or CD passthru (tuner specific)
-====== ======== =================================================
-
-GPIO 16(I believe) is tied to the IR port (if present).
-
-
-From the data sheet:
-
-- Register 24'h20004 PCI Interrupt Status
-
- - bit [18] IR_SMP_INT Set when 32 input samples have been collected over
- - gpio[16] pin into GP_SAMPLE register.
-
-What's missing from the data sheet:
-
-- Setup 4KHz sampling rate (roughly 2x oversampled; good enough for our RC5
- compat remote)
-- set register 0x35C050 to 0xa80a80
-- enable sampling
-- set register 0x35C054 to 0x5
-- enable the IRQ bit 18 in the interrupt mask register (and
- provide for a handler)
-
-GP_SAMPLE register is at 0x35C058
-
-Bits are then right shifted into the GP_SAMPLE register at the specified
-rate; you get an interrupt when a full DWORD is received.
-You need to recover the actual RC5 bits out of the (oversampled) IR sensor
-bits. (Hint: look for the 0/1and 1/0 crossings of the RC5 bi-phase data) An
-actual raw RC5 code will span 2-3 DWORDS, depending on the actual alignment.
-
-I'm pretty sure when no IR signal is present the receiver is always in a
-marking state(1); but stray light, etc can cause intermittent noise values
-as well. Remember, this is a free running sample of the IR receiver state
-over time, so don't assume any sample starts at any particular place.
-
-Additional info
-~~~~~~~~~~~~~~~
-
-This data sheet (google search) seems to have a lovely description of the
-RC5 basics:
-http://www.atmel.com/dyn/resources/prod_documents/doc2817.pdf
-
-This document has more data:
-http://www.nenya.be/beor/electronics/rc5.htm
-
-This document has a how to decode a bi-phase data stream:
-http://www.ee.washington.edu/circuit_archive/text/ir_decode.txt
-
-This document has still more info:
-http://www.xs4all.nl/~sbp/knowledge/ir/rc5.htm
diff --git a/Documentation/media/v4l-drivers/index.rst b/Documentation/media/v4l-drivers/index.rst
index 52d7c8d14ee7..dfc878c050da 100644
--- a/Documentation/media/v4l-drivers/index.rst
+++ b/Documentation/media/v4l-drivers/index.rst
@@ -68,6 +68,7 @@ For more details see the file COPYING in the source distribution of Linux.

bttv-devel
cpia2_devel
+ cx88-devel
vimc-devel

meye-uapi
--
2.24.1