Thread (7 messages) 7 messages, 3 authors, 2015-03-12

Re: [PATCH v2 07/18] drivers: reset: Add STM32 reset driver

From: Philipp Zabel <p.zabel@pengutronix.de>
Date: 2015-03-11 13:09:37
Also in: linux-api, linux-arch, linux-arm-kernel, linux-devicetree, linux-gpio, lkml

Am Dienstag, den 10.03.2015, 22:20 +0100 schrieb Maxime Coquelin:
2015-03-10 21:21 GMT+01:00 Arnd Bergmann [off-list ref]:
quoted
On Tuesday 10 March 2015 16:44:24 Maxime Coquelin wrote:
quoted
2015-03-10 16:02 GMT+01:00 Arnd Bergmann [off-list ref]:
quoted
On Friday 20 February 2015 19:01:06 Maxime Coquelin wrote:
quoted
+/* AHB1 */
+#define GPIOA_RESET    0
+#define GPIOB_RESET    1
+#define GPIOC_RESET    2
+#define GPIOD_RESET    3
+#define GPIOE_RESET    4
+#define GPIOF_RESET    5
+#define GPIOG_RESET    6
+#define GPIOH_RESET    7
+#define GPIOI_RESET    8
+#define GPIOJ_RESET    9
+#define GPIOK_RESET    10
As these are just the hardware numbers, it's better to not make them
part of the binding at all. Instead, just document in the binding that
one is supposed to pass the hardware number as the argument.
The reset controller is part of the RCC (Reset & Clock Controller) IP.
In this version, I only provided the reset registers to the reset
controller driver, but as per Andreas Färber remark, I should avec a
single DT node for both the resets and clocks.

In the next version I am preparing, the defines doesn't look as
trivial as in this version, GPIOA_RESET being 128 for instance.

Is it fine for you if I keep the defines part of the binding?
It's always better to avoid these files entirely, as they are
a frequent source of merge dependencies, and they make it less
obvious what's going on than having binary values in the dtb
that make sense.
I agree it is always painful to have to have to manage these merge dependencies.
What I will do, if Philipp agrees, is to list all the values in the
binding documentation.

Doing that, the user of a reset won't have to do the calculation, and
no more merge dependencies.
I'd prefer to have #defines for the reset bits if they are named in the
documentation and use the names in the dts. But if you want to reference
reset bits by number in the device tree instead, I won't insist.

Consider using two cells in the phandle for register and bit offset
instead of a single number that arbitrarily starts at 128.

regards
Philipp
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