[U-Boot] [PATCH v2 8/9] tegra: add SPI SLINK driver
Stephen Warren
swarren at wwwdotorg.org
Mon Jan 14 19:49:53 CET 2013
On 01/12/2013 09:56 AM, Simon Glass wrote:
> Hi,
>
> On Sat, Jan 12, 2013 at 1:07 AM, Allen Martin <amartin at nvidia.com> wrote:
>> Add driver for tegra SPI "SLINK" style driver. This controller is
>> similar to the tegra20 SPI "SFLASH" controller. The difference is
>> that the SLINK controller is a genernal purpose SPI controller and the
>> SFLASH controller is special purpose and can only talk to FLASH
>> devices. In addition there are potentially many instances of an SLINK
>> controller on tegra and only a single instance of SFLASH. Tegra20 is
>> currently ths only version of tegra that instantiates an SFLASH
>> controller.
>>
>> This driver supports basic PIO mode of operation and is configurable
>> (CONFIG_OF_CONTROL) to be driven off devicetree bindings. Up to 4
>> devices per controller may be attached, although typically only a
>> single chip select line is exposed from tegra per controller so in
>> reality this is usually limited to 1.
>>
>> To enable this driver, use CONFIG_TEGRA_SLINK
>> diff --git a/drivers/spi/tegra_slink.c b/drivers/spi/tegra_slink.c
>> +#ifdef CONFIG_OF_CONTROL
>
> You probably don't need this ifdef
If we did assume CONFIG_OF_CONTROL was on, then we could get rid of the
previous patch; all the device addresses would come from device tree, so
there would be no need to add them to any header file:-)
>> +void spi_init(void)
>> +{
>> + int node = 0, i;
>> + struct tegra_spi_ctrl *ctrl;
>
> blank line here
>
>> + for (i = 0; i < CONFIG_TEGRA_SLINK_CTRLS; i++) {
>> + ctrl = &spi_ctrls[i];
>> +#ifdef CONFIG_OF_CONTROL
>> + node = fdtdec_next_compatible(gd->fdt_blob, node,
>> + COMPAT_NVIDIA_TEGRA20_SLINK);
>> + if (!node)
>> + break;
>
> I think you should be using fdtdec_find_aliases_for_id() so that aliases work.
I strongly believe we shouldn't be using aliases for enumeration, which
is what fdtdec_find_aliases_for_id() does, IIRC. Instead, we should
enumerate all the devices in the correct fashion, and then apply aliases
as a separate step if they exists. Hence, I believe it's not correct to
use fdtdec_find_aliases_for_id() anywhere.
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