On 06/16/2017 11:35 AM, Bjorn Andersson wrote:
The npins here would allow us to properly name the multiple pins in e.g.
sdcX_data. But we're not doing this and I would be surprised if anyone
found it useful to get this in.
But how would that work? Each group is a single TLMM block, which only
has one bit for I/O. You can't actually program more than one pin from
a group.
struct msm_pingroup {
...
unsigned in_bit:5;
unsigned out_bit:5;
This only lets you define one bit for input, and one bit for output, for
any group.
So it make sense to hardcode this value in msm_get_group_pins() and drop
it from the struct.
I might submit a patch for that later.
It's not an awesome solution for mobile either. But to solve this we
have two problems to solve;
1) as the XPU configuration isn't fixed we need to be dynamic or
configurable in some sensible way
I was planning on updating the TLMM ACPI node to include a property that
lists the acceptable GPIOs.
But this list is related to your XPU configuration and not the TLMM
block, so the list of enabled/disabled pins should not go in the driver.
It goes in the ACPI table, and the driver reads that, and then (ideally)
creates an array of msm_pingroup objects that reflects the list in ACPI.
I'm hoping there's a way to modify msm_gpio_init() so that it parses the
array, and looks for "unavilable" groups. For example, if npins == 0,
that would be one way to know that this group doesn't actually exist.
For example, instead of calling gpiochip_add_pin_range(), maybe it would
call gpiochip_add_pingroup_range() instead. Unfortunately, I just don't
understand the gpiochip functions well enough to know what to do. I
need help in this area.
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