Astrometa DVB-T2 2018 update

Enable Sony CXD2837ER slave demon on the Astrometa DVB-T2, known as the 2018 update.

Originally based on the patch by kapitanf at https://github.com/torvalds/linux/pull/567, it was not quite right. This is more correct, but probably still wrong. I'm not a kernel dev, but someone may be better positioned to handle the niceties.
  

On Mon, Nov 05, 2018 at 07:12:52PM +0000, Bob Goddard wrote:
> Enable Sony CXD2837ER slave demon on the Astrometa DVB-T2, known as the 2018 update.
> 
> Originally based on the patch by kapitanf at https://github.com/torvalds/linux/pull/567, it was not quite right. This is more correct, but probably still wrong. I'm not a kernel dev, but someone may be better positioned to handle the niceties.

Before this patch can be accepted, we need a Signed-off-by: from the
original author, see:

https://www.kernel.org/doc/html/v4.12/process/submitting-patches.html?highlight=signed%20off#sign-your-work-the-developer-s-certificate-of-origin

> 
> 
> 
> diff --git a/drivers/media/usb/dvb-usb-v2/Kconfig b/drivers/media/usb/dvb-usb-v2/Kconfig
> index df4412245a8a..d44ddd5ee29e 100644
> --- a/drivers/media/usb/dvb-usb-v2/Kconfig
> +++ b/drivers/media/usb/dvb-usb-v2/Kconfig
> @@ -137,6 +137,7 @@ config DVB_USB_RTL28XXU
>  	select DVB_RTL2832
>  	select DVB_RTL2832_SDR if (MEDIA_SUBDRV_AUTOSELECT && MEDIA_SDR_SUPPORT)
>  	select DVB_SI2168 if MEDIA_SUBDRV_AUTOSELECT
> +	select DVB_CXD2841ER if MEDIA_SUBDRV_AUTOSELECT
>  	select MEDIA_TUNER_E4000 if MEDIA_SUBDRV_AUTOSELECT
>  	select MEDIA_TUNER_FC0012 if MEDIA_SUBDRV_AUTOSELECT
>  	select MEDIA_TUNER_FC0013 if MEDIA_SUBDRV_AUTOSELECT
> diff --git a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
> index a970224a94bd..db4f4da43781 100644
> --- a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
> +++ b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
> @@ -386,6 +386,7 @@ static int rtl2832u_read_config(struct dvb_usb_device *d)
>  	struct rtl28xxu_req req_mn88473 = {0xff38, CMD_I2C_RD, 1, buf};
>  	struct rtl28xxu_req req_si2157 = {0x00c0, CMD_I2C_RD, 1, buf};
>  	struct rtl28xxu_req req_si2168 = {0x00c8, CMD_I2C_RD, 1, buf};
> +	struct rtl28xxu_req req_cxd2837er = {0x68d8, CMD_I2C_RD, 1, buf};
>  
>  	dev_dbg(&d->intf->dev, "\n");
>  
> @@ -567,6 +568,13 @@ static int rtl2832u_read_config(struct dvb_usb_device *d)
>  			dev->slave_demod = SLAVE_DEMOD_MN88473;
>  			goto demod_found;
>  		}
> +
> +		ret = rtl28xxu_ctrl_msg(d, &req_cxd2837er);
> +		if (ret == 0 && buf[0] == 0x03) {
> +			dev_dbg(&d->intf->dev, "CXD2837ER found");
> +			dev->slave_demod = SLAVE_DEMOD_CXD2841ER;
> +			goto demod_found;
> +		}
>  	}
>  	if (dev->tuner == TUNER_RTL2832_SI2157) {
>  		/* check Si2168 ID register; reg=c8 val=80 */
> @@ -988,6 +996,27 @@ static int rtl2832u_frontend_attach(struct dvb_usb_adapter *adap)
>  				goto err_slave_demod_failed;
>  			}
>  
> +			dev->i2c_client_slave_demod = client;
> +		} else if (dev->slave_demod == SLAVE_DEMOD_CXD2841ER) {
> +			struct cxd2841er_config cxd2837er_config = {};
> +			cxd2837er_config.i2c_addr = 0xd8;
> +			cxd2837er_config.xtal = SONY_XTAL_20500;
> +			cxd2837er_config.flags = CXD2841ER_AUTO_IFHZ    | CXD2841ER_EARLY_TUNE |
> +				    CXD2841ER_NO_WAIT_LOCK | CXD2841ER_NO_AGCNEG  |
> +				    CXD2841ER_TSBITS       | CXD2841ER_TS_SERIAL;
> +
> +			adap->fe[1] = dvb_attach( cxd2841er_attach_t_c, &cxd2837er_config, &d->i2c_adap );

Unneeded spaces around function arguments.

> +			if (!adap->fe[1]) {
> +				dev_err(&d->intf->dev, "CXD2837ER attach failed!\n");
> +				return -ENODEV;
> +			}
> +
> +			if (!try_module_get(client->dev.driver->owner)) {
> +				i2c_unregister_device(client);
> +				dev->slave_demod = SLAVE_DEMOD_NONE;
> +				goto err_slave_demod_failed;
> +			}
> +
>  			dev->i2c_client_slave_demod = client;
>  		} else {
>  			struct si2168_config si2168_config = {};
> @@ -1046,10 +1075,14 @@ static int rtl28xxu_frontend_detach(struct dvb_usb_adapter *adap)
>  	dev_dbg(&d->intf->dev, "\n");
>  
>  	/* remove I2C slave demod */
> -	client = dev->i2c_client_slave_demod;
> -	if (client) {
> -		module_put(client->dev.driver->owner);
> -		i2c_unregister_device(client);
> +	if (dev->slave_demod == SLAVE_DEMOD_CXD2841ER) {
> +		dev_info(&d->intf->dev,"Sony CXD2837ER detached automatically.");

For one thing the reference count for the module was increased on attach,
so we should also decrease it on dettach. Why are we not unregistering
the i2c device?

> +	} else {
> +		client = dev->i2c_client_slave_demod;
> +		if (client) {
> +			module_put(client->dev.driver->owner);
> +			i2c_unregister_device(client);
> +		}
>  	}
>  
>  	/* remove I2C demod */
> diff --git a/drivers/media/usb/dvb-usb-v2/rtl28xxu.h b/drivers/media/usb/dvb-usb-v2/rtl28xxu.h
> index 138062960a73..5a615d73fc34 100644
> --- a/drivers/media/usb/dvb-usb-v2/rtl28xxu.h
> +++ b/drivers/media/usb/dvb-usb-v2/rtl28xxu.h
> @@ -43,6 +43,7 @@
>  #include "r820t.h"
>  #include "si2168.h"
>  #include "si2157.h"
> +#include "cxd2841er.h"
>  
>  /*
>   * USB commands
> @@ -87,7 +88,8 @@ struct rtl28xxu_dev {
>  	#define SLAVE_DEMOD_MN88472        1
>  	#define SLAVE_DEMOD_MN88473        2
>  	#define SLAVE_DEMOD_SI2168         3
> -	unsigned int slave_demod:2;
> +	#define SLAVE_DEMOD_CXD2841ER      4
> +	unsigned int slave_demod:3;
>  	union {
>  		struct rtl2830_platform_data rtl2830_platform_data;
>  		struct rtl2832_platform_data rtl2832_platform_data;
> 
>