Re: [PATCH v2 05/11] ARM: dt: tegra30: Add device node for APB MISC

From: Prashant Gaikwad
Date: Thu Jan 03 2013 - 20:48:15 EST

On Thursday 03 January 2013 09:41 PM, Stephen Warren wrote:
On 01/02/2013 11:11 PM, Prashant Gaikwad wrote:
On Thursday 03 January 2013 03:30 AM, Stephen Warren wrote:
On 12/27/2012 07:47 AM, Prashant Gaikwad wrote:
APB misc contains multiple registers required by different modules
such as CAR.
I don't see a DT binding document that describes what
nvidia,tegra30-apbmisc means. Also, the register range for this new node
overlaps that for the pinmux node, so they can't both "request" their
register region. You may need multiple entries in the apbmisc reg
property to avoid this.
apbmisc reg for Tegra30 can be divided into following entries:

strap registers
jtag configuration registers
pull_up/pull_down control registers
vclk control registers
tvdac registers
chip id revision registers
pad control registers

This list is not same for Tegra20 and Tegra30.
OK. It sounds like we need a true APB MISC driver then, to abstract the
differences; the clock driver really shouldn't be touching the APB MISC
registers in all likelihood, unless a subset of the sections you mention
above are truly dedicated to clock functionality.

I don't think it is a good idea to create a driver for APB MISC, all registers are used by different drivers.
Only chip id revision registers are used in clock driver.


another way is to add chip id revision register region to CAR node as
done for pinmux node and remove apb misc node.
The pinmux controller doesn't have a reg entry for the chip ID register.
I don't understand what you mean here.

I mean as we have separate entry for PAD control registers region in pinmux node we can have also have separate entry for chid id revision register region in CAR node.

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