Re: [RFC PATCH 2/3] radio-keene: add a driver for the Keene FM Transmitter.

[Hans Verkuil <hverkuil@xs4all.nl>]

On Monday 16 January 2012 13:44:37 Oliver Neukum wrote:
> Am Montag, 16. Januar 2012, 13:29:19 schrieb Hans Verkuil:
> > From: Hans Verkuil <hans.verkuil@cisco.com>
> > 
> > +MODULE_DEVICE_TABLE(usb, usb_keene_device_table);
> > +
> > +struct keene_device {
> > +	struct usb_device *usbdev;
> > +	struct usb_interface *intf;
> > +	struct video_device vdev;
> > +	struct v4l2_device v4l2_dev;
> > +	struct v4l2_ctrl_handler hdl;
> > +	struct mutex lock;
> > +
> > +	u8 buffer[BUFFER_LENGTH];
> 
> This is a violation of the DMA  API. You need to alocate the buffer with
> a separate kmalloc.

OK.

> > +	unsigned curfreq;
> > +	u8 tx;
> > +	u8 pa;
> > +	bool stereo;
> > +	bool muted;
> > +	bool preemph_75_us;
> > +};
> > +
> > +static inline struct keene_device *to_keene_dev(struct v4l2_device
> > *v4l2_dev) +{
> > +	return container_of(v4l2_dev, struct keene_device, v4l2_dev);
> > +}
> > +
> > +/* Set frequency (if non-0), PA, mute and turn on/off the FM
> > transmitter. */ +static int keene_cmd_main(struct keene_device *radio,
> > unsigned freq, bool play) +{
> > +	unsigned short freq_send = freq ? (freq - 76 * 16000) / 800 : 0;
> > +	int ret;
> > +
> > +	radio->buffer[0] = 0x00;
> > +	radio->buffer[1] = 0x50;
> > +	radio->buffer[2] = (freq_send >> 8) & 0xff;
> > +	radio->buffer[3] = freq_send & 0xff;
> 
> Please use the endianness macro appropriate here

I don't see any endianness issues here, but perhaps I missed something.

Regards,

	Hans