On Mon, Jan 14, 2013 at 10:49:53AM -0800, Stephen Warren wrote:
On 01/12/2013 09:56 AM, Simon Glass wrote:
Hi,
On Sat, Jan 12, 2013 at 1:07 AM, Allen Martin amartin@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:-)
I took Simon's comment to mean it's safe to include fdtdec.h even if the fdt code is ifdef'ed out.
+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.
I'm a bit confused about the usage of fdt aliases in u-boot. My understanding of aliases is that they are intended to give drivers hints about device naming. Since u-boot doesn't really name devices, what are aliases supposed to do?
-Allen