[Meego-kernel] [Meego Kernel][PATCH] Add support for modem firmware download

[Alan Cox]

On Wed, 13 Oct 2010 17:28:37 -0700
"Mills, Ken K" <ken.k.mills at intel.com> wrote:

> This patch adds two new ioctl functions to the IFX protocol driver
> that allows the setting of the SPI message transfer size to either
> 2048 or 2060 bytes. This is to enable modem firmware download over
> SPI.

What is the use model for the firmware download. How will I do the
download bit ?


> @@ -682,6 +684,7 @@ static int ifx_spi_ioctl(struct tty_struct *tty,
> struct file *file, unsigned int cmd, unsigned long arg)
>  {
>  	int nreset;
> +	int transfer_size;

Should probably an unsigned fixed size type (eg u32)

>  	struct ifx_spi_device *ifx_dev = saved_ifx_dev;
>  
>  	dev_dbg(&ifx_dev->spi_dev->dev,
> @@ -698,6 +701,31 @@ static int ifx_spi_ioctl(struct tty_struct *tty,
> struct file *file, return -EFAULT;
>  		break;
>  
> +	case IFX_GET_SPI_TRANSFER_SIZE:
> +		if (!capable(CAP_SYS_RAWIO))
> +			return -EPERM;
> +		transfer_size = ifx_dev->ifx_transfer_size;
> +		if (copy_to_user((int __user *)arg, &transfer_size,
> +			sizeof(int)))
> +			return -EFAULT;

	return put_user(....)

(and no real need for a private copy first)

> +		break;
> +
> +	case IFX_SET_SPI_TRANSFER_SIZE:
> +		if (!capable(CAP_SYS_RAWIO))
> +			return -EPERM;
> +		if (arg == 0) {
> +			ifx_dev->ifx_transfer_size =

It would be more symmetrical to pass the actual size in and check for
2048/2060 (oh yes and what occurs if neither is true for 0/1). Passing
the value also means that the interface doesn't change if a new chip
needs a different size setup.



>  	/*initialize transfer and dma buffers */
> -	ifx_dev->tx_buffer = kzalloc(IFX_SPI_TRANSFER_SIZE,
> +	ifx_dev->tx_buffer = kzalloc(IFX_SPI_MAX_BUFFER_SIZE,
>  		GFP_KERNEL | GFP_DMA);

These are still wrong - you need to use the dma_alloc_ functions for
DMAable buffers.