On 19.08.2020 06:23, Florian Fainelli wrote:
The pin controller resources start at 0xc0 from the CRU base which is at
0x100 from th DMU base, for a final address of 0x1800_c1c0, whereas we
are currently off by 0x100. The resource size of the CRU is also
incorrect and should end at 0x248 bytes from 0x100 which is the start
address. Finally, the compatibility strings defined for the
pin-controller node should reflect the SoC being used.
I can confirm 0x1800c1c0 is the correct absolute offset.
diff --git a/arch/arm/boot/dts/bcm5301x.dtsi b/arch/arm/boot/dts/bcm5301x.dtsi
index 2d9b4dd05830..bf49943f504a 100644
--- a/arch/arm/boot/dts/bcm5301x.dtsi
+++ b/arch/arm/boot/dts/bcm5301x.dtsi
@@ -402,14 +402,14 @@ dmu@1800c000 {
cru@100 {
compatible = "simple-bus";
- reg = <0x100 0x1a4>;
+ reg = <0x100 0x248>;
ranges;
#address-cells = <1>;
#size-cells = <1>;
- pin-controller@1c0 {
- compatible = "brcm,bcm4708-pinmux";
- reg = <0x1c0 0x24>;
+ pinctrl: pin-controller@c0 {
+ compatible = "brcm,bcm53012-pinmux";
+ reg = <0xc0 0x24>;
reg-names = "cru_gpio_control";
spi-pins {
That whole binding has a bit messy story.
Initially it used to be binding like:
compatible = "brcm,bcm4708-pinmux";
reg = <0x1800c1c0 0x24>;
reg-names = "cru_gpio_control";
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c12fb1774deaa9c9408b19db8d43d3612f6e47a0
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3f9f82b3ffb8bfe01988c890e3a24328e9e1c1df
Later example binding was rewritten to include dmu and cru (simplified
below):
dmu@1800c000 {
compatible = "simple-bus";
ranges = <0 0x1800c000 0x1000>;
cru@100 {
compatible = "simple-bus";
reg = <0x100 0x1a4>;
ranges;
pin-controller@1c0 {
compatible = "brcm,bcm4708-pinmux";
reg = <0x1c0 0x24>;
reg-names = "cru_gpio_control";
};
};
};
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=93d39737b29eaf1974bf850ccdc903b2418c800b
I don't understand or remember why pin-controller reg was relative to
dmu instead of cru. Some DT offset calculation magic?
Finally I updated binding to use "offset", see:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2ae80900f239484069569380e1fc4340fd6e0089
and then updated driver to follow:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a49d784d5a8272d0f63c448fe8dc69e589db006e
but I never updated DTS file accordingly.
To OpenWrt I pushed relevant kernel patch in the commit:
https://git.openwrt.org/?p=openwrt/openwrt.git;a=commitdiff;h=a28f6ab27f9ae1a08c6945013cdb796b12ce150d
(called [PATCH] ARM: dts: BCM5301X: Update Northstar pinctrl binding)
but I never sent it upstream.
Florian: your change doesn't match docs or existing Linux driver:
1. Driver seems to ignore "reg"
2. Driver requires "offset"
3. Property "cru_gpio_control" is leftover (undocumented and unused)
I think we need to take a step back and cleanup Northstar bindings. Few
months ago I sent e-mail:
Subject: Proper DT bindings for Broadcom's DMU node
Message-ID: <7da2db8f-66d0-24ec-d3eb-84247b383a06@xxxxxxxxx>
I didn't get any reply from Rob who previously pointed out that
compatible = "syscon", "simple-mfd";
is not a valid compatibility.
I suggest we hold on on DTS update for a moment and switch back to my
question from March on designing proper bindings.
