On 08/26/2013 06:33 AM, Stefano Babic wrote:
Hi Tapani,
On 26/08/2013 13:12, Tapani wrote:
Macros wee added exactly in the time they needed, and maybe a global look was missing.
However, can you provide much more detail about this ? Which macros, in which files ?
The macros I refer to is the MX6_PAD_ ones. The semantics of them depends on the target cpu. See arch/arm/include/asm/arch-mx6/mx6-pins.h
Ok - these files are not thought to be used in the same binary, we have to change something, taking into account we should remain compatible without breaking the currently supported boards.
Let's start with some proposals. Maybe you have already introduced a CONFIG_ switch, because at the moment only one SOC per image is supported, and one of MX6Q, MX6DL must be set. We have also the same issue with -ddr files (mx6q-ddr and mx6dl-ddr). Let's say we add a CONFIG_MX6_MULTI to support all SocS at the same time.
Then we could change the file you mention adding a suffix to each pin. For example, in mx6q_pins.h we could add something like this:
#ifdef CONFIG_MX6_MULTI #define PAD_SUFFIX _6Q #else #define PAD_SUFFIX #endif
And we add the macro to each pin, such as enum { MX6_PAD_SD2_DAT1__USDHC2_DAT1##PAD_SUFFIX
In this way we could have different names only if we support multiple SOCs. We need then some accessors to get the right pin, something like mx6_pin(soc_type, pin_name), that returns the right configuration. Of course, this is a very first draft, and someone else can start with different proposals.
:)
This is where we started on i.MX6, with prefixes MX6Q and MX6DL. See commit cfb8b9d.
Generally I would avoid to convert the enums into tables, because they will increase the footprint for each board.
Functionally, we still need table(s) for any image which supports either variant so the proper set of pads are configured.
See this for an example http://lists.denx.de/pipermail/u-boot/2012-October/136394.html
The construct used in that patch set was to define FOR_DL_SOLO, then include the pad file. #ifdef CONFIG_MX6Q #include "pads.h" #endif #if defined(CONFIG_MX6DL) || defined(CONFIG_MX6S) #define FOR_DL_SOLO #include "pads.h" #endif
Troy's implementation used a naming convention of mx6q_X and mx6dl_solo_X such that a board supporting both would have variables
static iomux_v3_cfg_t mx6q_usdhc3_pads = ...
followed by
static iomux_v3_cfg_t mx6dl_solo_usdhc3_pads = ...
Some other data structures were also duplicated with the same naming convention (see i2c_pads).
Regards,
Eric