Re: How to proceed ? => [PATCH ?] EM28xx driver ?

[mjs <mjstork@gmail.com>]

Op Mon, 23 Apr 2018 14:15:59 -0300
Mauro Carvalho Chehab <mchehab@s-opensource.com> schreef:

> Em Mon, 23 Apr 2018 12:35:06 -0400
> Alexandre-Xavier Labonté-Lamoureux         <axdoomer@gmail.com> escreveu:
> 
> > This should give you an idea of what you need to do:
> > https://linuxtv.org/wiki/index.php/Development:_How_to_submit_patches  
> 
> Yes.
> 
> In particular, you should send it against the upstream development Kernel,
> using "git diff", and add a proper description.


Thanks, I will read and use it.


> 
> Anyway, let review a few things. See below.
> > 
> > 
> > On Mon, Apr 23, 2018 at 3:18 AM, mjs <mjstork@gmail.com> wrote:  
> > > Hello,
> > >
> > > 4 years ago I started to try to make a dvb-t ":ZOLID Hybrid TV Stick" to work with linux.
> > >
> > > Today there is success at least for the digital part, not the analog or remote part.
> > >
> > > If and how to proceed adding this patch to the global source.
> > >
> > > Greatings,
> > >   Marcel Stork
> > >
> > >
> > > Git result:
> > >
> > > From ccea81c2a3c6e937d304a87fad823dd557937968 Mon Sep 17 00:00:00 2001
> > > From: mjs <mjs@toshiba>
> > > Date: Sun, 1 Apr 2018 19:10:33 +0200
> > > Subject: [PATCH]  Committer: mjs <mjs@toshiba>  On branch master
> > >  zolid-em28xx-driver  Changes to be committed:  modified:   em28xx-cards.c
> > >  modified:   em28xx-dvb.c       modified:   em28xx.h
> > >
> > > ---
> > >  em28xx-cards.c | 32 +++++++++++++++++++++++++++++---
> > >  em28xx-dvb.c   |  1 +
> > >  em28xx.h       |  1 +
> > >  3 files changed, 31 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/em28xx-cards.c b/em28xx-cards.c
> > > index e397f54..5024dd7 100644
> > > --- a/em28xx-cards.c
> > > +++ b/em28xx-cards.c
> > > @@ -92,6 +92,20 @@ static struct em28xx_reg_seq default_digital[] = {
> > >         {       -1,             -1,     -1,             -1},
> > >  };
> > >
> > > +static struct em28xx_reg_seq zolid_tuner[] = {
> > > +       {EM2820_R08_GPIO_CTRL,          0xfd,           0xff,   100},
> > > +       {EM2820_R08_GPIO_CTRL,          0xfe,           0xff,   100},
> > > +       {               -1,                                     -1,                     -1,              -1},
> > > +};
> > > +
> > > +static struct em28xx_reg_seq zolid_digital[] = {
> > > +       {EM2820_R08_GPIO_CTRL,          0x6a,           0xff,   100},
> > > +       {EM2820_R08_GPIO_CTRL,          0x7a,           0xff,   100},
> > > +       {EM2880_R04_GPO,                        0x04,           0xff,   100},
> > > +       {EM2880_R04_GPO,                        0x0c,           0xff,   100},
> > > +       {       -1,                                             -1,                     -1,              -1},
> > > +};
> > > +
> > >  /* Board Hauppauge WinTV HVR 900 analog */
> > >  static struct em28xx_reg_seq hauppauge_wintv_hvr_900_analog[] = {
> > >         {EM2820_R08_GPIO_CTRL,  0x2d,   ~EM_GPIO_4,     10},
> > > @@ -629,6 +643,17 @@ static struct em28xx_led hauppauge_dualhd_leds[] = {
> > >   *  Board definitions
> > >   */
> > >  struct em28xx_board em28xx_boards[] = {
> > > +
> > > +       [EM2882_BOARD_ZOLID_HYBRID_TV_STICK] = {
> > > +               .name                   = ":ZOLID HYBRID TV STICK",
> > > +               .tuner_type             = TUNER_XC2028,
> > > +               .tuner_gpio             = zolid_tuner,
> > > +               .decoder                = EM28XX_TVP5150,
> > > +               .xclk                   = EM28XX_XCLK_FREQUENCY_12MHZ,
> > > +               .mts_firmware   = 1,
> > > +               .has_dvb                = 1,
> > > +               .dvb_gpio               = zolid_digital,
> > > +       },
> > >         [EM2750_BOARD_UNKNOWN] = {
> > >                 .name          = "EM2710/EM2750/EM2751 webcam grabber",
> > >                 .xclk          = EM28XX_XCLK_FREQUENCY_20MHZ,
> > > @@ -2421,7 +2446,7 @@ struct usb_device_id em28xx_id_table[] = {
> > >         { USB_DEVICE(0xeb1a, 0x2881),
> > >                         .driver_info = EM2820_BOARD_UNKNOWN },
> > >         { USB_DEVICE(0xeb1a, 0x2883),
> > > -                       .driver_info = EM2820_BOARD_UNKNOWN },
> > > +                       .driver_info = EM2882_BOARD_ZOLID_HYBRID_TV_STICK },  
> 
> This is actually wrong. The USB address EB1A:2883 is the generic one
> with is hardcoded at the em28xx chip. All devices without eeprom 
> (or with an eeprom that doesn't set a vendor-specific ID) will
> announce this address.

The eeprom has this vid-pid ID (according to the em2882 data sheet).
em28xx #0: i2c eeprom 00: 1a eb 67 95 1a eb 83 28 d0 12 65 00 6a 22 8c 10
em28xx #0: i2c eeprom 10: 00 00 24 57 4e 37 01 00 60 00 00 00 02 00 00 00
and so on .....

> 
> So, instead of hardcoding, there are 3 alternatives:
> 
> 1) if the board has an eeprom (whose USB is not filled), there's
> a hint code that uses the eeprom to produce a hash;
> 2) if the board doesn't have, it could hint based on the devices
> reported via an i2c scan;
> 3) if none as above works for this board, the user has to force a
> modprobe parameter via card=<number>.

Option 1 and 2 are available (see below).
I have to try option 3 again with the knowledge of today (dit not work 4 years ago)

> 
> > >         { USB_DEVICE(0xeb1a, 0x2868),
> > >                         .driver_info = EM2820_BOARD_UNKNOWN },
> > >         { USB_DEVICE(0xeb1a, 0x2875),
> > > @@ -2599,6 +2624,7 @@ static struct em28xx_hash_table em28xx_eeprom_hash[] = {
> > >         {0xb8846b20, EM2881_BOARD_PINNACLE_HYBRID_PRO, TUNER_XC2028},
> > >         {0x63f653bd, EM2870_BOARD_REDDO_DVB_C_USB_BOX, TUNER_ABSENT},
> > >         {0x4e913442, EM2882_BOARD_DIKOM_DK300, TUNER_XC2028},
> > > +       {0x85dd871e, EM2882_BOARD_ZOLID_HYBRID_TV_STICK, TUNER_XC2028},
> > >  };
> > >
> > >  /* I2C devicelist hash table for devices with generic USB IDs */
> > > @@ -2610,6 +2636,7 @@ static struct em28xx_hash_table em28xx_i2c_hash[] = {
> > >         {0xc51200e3, EM2820_BOARD_GADMEI_TVR200, TUNER_LG_PAL_NEW_TAPC},
> > >         {0x4ba50080, EM2861_BOARD_GADMEI_UTV330PLUS, TUNER_TNF_5335MF},
> > >         {0x6b800080, EM2874_BOARD_LEADERSHIP_ISDBT, TUNER_ABSENT},
> > > +       {0x27e10080, EM2882_BOARD_ZOLID_HYBRID_TV_STICK, TUNER_XC2028},
> > >  };
> > >
> > >  /* NOTE: introduce a separate hash table for devices with 16 bit eeproms */
> > > @@ -3063,8 +3090,7 @@ void em28xx_setup_xc3028(struct em28xx *dev, struct xc2028_ctrl *ctl)
> > >         case EM2880_BOARD_EMPIRE_DUAL_TV:
> > >         case EM2880_BOARD_HAUPPAUGE_WINTV_HVR_900:
> > >         case EM2882_BOARD_TERRATEC_HYBRID_XS:
> > > -               ctl->demod = XC3028_FE_ZARLINK456;
> > > -               break;  
> 
> Why are you removing it? You will break support for the above boards.
> 

My line of thinking:

My original source is like:
	switch (dev->model) {
	case EM2880_BOARD_EMPIRE_DUAL_TV:
	case EM2880_BOARD_HAUPPAUGE_WINTV_HVR_900:
	case EM2882_BOARD_TERRATEC_HYBRID_XS:
		ctl->demod = XC3028_FE_ZARLINK456;
		break;
	case EM2880_BOARD_TERRATEC_HYBRID_XS:
	case EM2880_BOARD_TERRATEC_HYBRID_XS_FR:
	case EM2881_BOARD_PINNACLE_HYBRID_PRO:
		ctl->demod = XC3028_FE_ZARLINK456;
		break;

Deleting the two lines would give:
	switch (dev->model) {
	case EM2880_BOARD_EMPIRE_DUAL_TV:
	case EM2880_BOARD_HAUPPAUGE_WINTV_HVR_900:
	case EM2882_BOARD_TERRATEC_HYBRID_XS:
	case EM2880_BOARD_TERRATEC_HYBRID_XS:
	case EM2880_BOARD_TERRATEC_HYBRID_XS_FR:
	case EM2881_BOARD_PINNACLE_HYBRID_PRO:
		ctl->demod = XC3028_FE_ZARLINK456;
		break;

Put the two blobs together to get a reduction of lines because they seems to have the same result.
I was convinced not breaking some line of code unless there is a maximum of putting a number of "case......." together.
I think in this case the git-diff does not show the whole picture, additional explanation from my side would have been better.


> > > +       case EM2882_BOARD_ZOLID_HYBRID_TV_STICK:
> > >         case EM2880_BOARD_TERRATEC_HYBRID_XS:
> > >         case EM2880_BOARD_TERRATEC_HYBRID_XS_FR:
> > >         case EM2881_BOARD_PINNACLE_HYBRID_PRO:
> > > diff --git a/em28xx-dvb.c b/em28xx-dvb.c
> > > index 1a5c012..e18d048 100644
> > > --- a/em28xx-dvb.c
> > > +++ b/em28xx-dvb.c
> > > @@ -1197,6 +1197,7 @@ static int em28xx_dvb_init(struct em28xx *dev)
> > >         case EM2880_BOARD_HAUPPAUGE_WINTV_HVR_900:
> > >         case EM2882_BOARD_TERRATEC_HYBRID_XS:
> > >         case EM2880_BOARD_EMPIRE_DUAL_TV:
> > > +       case EM2882_BOARD_ZOLID_HYBRID_TV_STICK:
> > >                 dvb->fe[0] = dvb_attach(zl10353_attach,
> > >                                            &em28xx_zl10353_xc3028_no_i2c_gate,
> > >                                            &dev->i2c_adap[dev->def_i2c_bus]);
> > > diff --git a/em28xx.h b/em28xx.h
> > > index d148463..d786bfa 100644
> > > --- a/em28xx.h
> > > +++ b/em28xx.h
> > > @@ -147,6 +147,7 @@
> > >  #define EM2884_BOARD_ELGATO_EYETV_HYBRID_2008     97
> > >  #define EM28178_BOARD_PLEX_PX_BCUD                98
> > >  #define EM28174_BOARD_HAUPPAUGE_WINTV_DUALHD_DVB  99
> > > +#define EM2882_BOARD_ZOLID_HYBRID_TV_STICK       100
> > >
> > >  /* Limits minimum and default number of buffers */
> > >  #define EM28XX_MIN_BUF 4
> > > --
> > > 2.11.0    
> 

I'll do my best.
Thanks,

 Marcel