Thread (16 messages) 16 messages, 5 authors, 2019-01-07

Re: [PATCH v5 5/6] dt-bindings: pinctrl: mt8183: add binding document

From: Sean Wang <sean.wang@kernel.org>
Date: 2019-01-04 09:55:09
Also in: linux-arm-kernel, linux-clk, linux-mediatek, linux-serial, lkml

On Fri, Jan 4, 2019 at 1:40 AM Zhiyong Tao [off-list ref] wrote:
On Fri, 2019-01-04 at 01:14 -0800, Sean Wang wrote:
quoted
On Thu, Jan 3, 2019 at 11:09 PM Zhiyong Tao [off-list ref] wrote:
quoted
On Sat, 2018-12-29 at 06:04 +0800, Rob Herring wrote:
quoted
On Fri, Dec 28, 2018 at 04:09:40PM +0800, Erin Lo wrote:
quoted
From: Zhiyong Tao <redacted>

The commit adds mt8183 compatible node in binding document.

Signed-off-by: Zhiyong Tao <redacted>
Signed-off-by: Erin Lo <redacted>
---
 .../devicetree/bindings/pinctrl/pinctrl-mt8183.txt | 110 +++++++++++++++++++++
 1 file changed, 110 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pinctrl/pinctrl-mt8183.txt
diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8183.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8183.txt
new file mode 100644
index 0000000..7b5285e
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8183.txt
@@ -0,0 +1,110 @@
+* Mediatek MT8183 Pin Controller
+
+The Mediatek's Pin controller is used to control SoC pins.
+
+Required properties:
+- compatible: value should be one of the following.
+   "mediatek,mt8183-pinctrl", compatible with mt8183 pinctrl.
+- gpio-controller : Marks the device node as a gpio controller.
+- #gpio-cells: number of cells in GPIO specifier. Since the generic GPIO
+  binding is used, the amount of cells must be specified as 2. See the below
+  mentioned gpio binding representation for description of particular cells.
+- gpio-ranges : gpio valid number range.
+
+   Eg: <&pio 6 0>
+   <[phandle of the gpio controller node]
+   [line number within the gpio controller]
+   [flags]>
+
+   Values for gpio specifier:
+   - Line number: is a value between 0 to 202.
+   - Flags:  bit field of flags, as defined in <dt-bindings/gpio/gpio.h>.
+            Only the following flags are supported:
+            0 - GPIO_ACTIVE_HIGH
+            1 - GPIO_ACTIVE_LOW
+
+Optional properties:
+- reg: physicall address base for gpio base registers.
s/physicall/physical/

reg should never be optional.

Need to say how many reg entries.
==> Thanks for your suggestion. We will change 'reg' to Required
properties and add the reg entries in next version.
quoted
quoted
+- reg-names: gpio base registers name.
Need to say what are the names. However, I don't find the names in the
example all that useful, so I'd just drop it.
==> we will add the reg-names in next version.
They are used in the sample code, such as:
quoted
+             reg-names = "iocfg0", "iocfg1", "iocfg2",
quoted
+                       "iocfg3", "iocfg4", "iocfg5",
+                       "iocfg6", "iocfg7", "iocfg8";
quoted
quoted
+- interrupt-controller: Marks the device node as an interrupt controller
+- #interrupt-cells: Should be two.
+- interrupts : The interrupt outputs from the controller.
+
+Please refer to pinctrl-bindings.txt in this directory for details of the
+common pinctrl bindings used by client devices.
+
+Subnode format
+A pinctrl node should contain at least one subnodes representing the
+pinctrl groups available on the machine. Each subnode will list the
+pins it needs, and how they should be configured, with regard to muxer
+configuration, pullups, drive strength, input enable/disable and input schmitt.
+
+    node {
+   pinmux = <PIN_NUMBER_PINMUX>;
+   GENERIC_PINCONFIG;
+    };
+
+Required properties:
+- pinmux: integer array, represents gpio pin number and mux setting.
+    Supported pin number and mux varies for different SoCs, and are defined
+    as macros in boot/dts/<soc>-pinfunc.h directly.
+
+Optional properties:
+- GENERIC_PINCONFIG: is the generic pinconfig options to use, bias-disable,
+    bias-pull-down, bias-pull-up, input-enable, input-disable, output-low, output-high,
+    input-schmitt-enable, input-schmitt-disable and drive-strength are valid.
+
+    Some special pins have extra pull up strength, there are R0 and R1 pull-up
+    resistors available, but for user, it's only need to set R1R0 as 00, 01, 10 or 11.
+    So when config mediatek,pull-up-adv or mediatek,pull-down-adv,
+    it support arguments for those special pins.
+
+    When config drive-strength, it can support some arguments, such as
+    MTK_DRIVE_4mA, MTK_DRIVE_6mA, etc. See dt-bindings/pinctrl/mt65xx.h.
+
One point we can fix more is the drive-strength already is supported
as the generic one, not need to depend on a dedicated header file.
==> We think that we use MTK_DRIVE_4mA to set as driving in dts. it it
more clear in v2 common driver for single pin -> single group mode.
How about the idea?
Sure, thank for post your idea and it sounds not bad to keep the
convention for the single pin -> single group mode binding.
Thanks.
quoted
quoted
quoted
quoted
+Examples:
+
+#include "mt8183-pinfunc.h"
+
+...
+{
+   pio: pinctrl@10005000 {
+           compatible = "mediatek,mt8183-pinctrl";
+           reg = <0 0x10005000 0 0x1000>,
+                 <0 0x11F20000 0 0x1000>,
+                 <0 0x11E80000 0 0x1000>,
+                 <0 0x11E70000 0 0x1000>,
+                 <0 0x11E90000 0 0x1000>,
+                 <0 0x11D30000 0 0x1000>,
+                 <0 0x11D20000 0 0x1000>,
+                 <0 0x11C50000 0 0x1000>,
+                 <0 0x11F30000 0 0x1000>;
+           reg-names = "iocfg0", "iocfg1", "iocfg2",
+                       "iocfg3", "iocfg4", "iocfg5",
+                       "iocfg6", "iocfg7", "iocfg8";
+           gpio-controller;
+           #gpio-cells = <2>;
+           gpio-ranges = <&pio 0 0 192>;
+           interrupt-controller;
+           interrupts = <GIC_SPI 153 IRQ_TYPE_LEVEL_HIGH>;
+           interrupt-parent = <&gic>;
+           #interrupt-cells = <2>;
+
+           i2c0_pins_a: i2c0@0 {
unit-address without reg property is not valid.
==> we will change "i2c0_pins_a: i2c0@0" to "i2c0_pins_a: i2c0" in the
next version.
quoted
quoted
+                   pins1 {
+                           pinmux = <PINMUX_GPIO48__FUNC_SCL5>,
+                                    <PINMUX_GPIO49__FUNC_SDA5>;
+                           mediatek,pull-up-adv = <11>;
+                   };
+           };
+
+           i2c1_pins_a: i2c1@0 {
+                   pins {
+                           pinmux = <PINMUX_GPIO50__FUNC_SCL3>,
+                                    <PINMUX_GPIO51__FUNC_SDA3>;
+                           mediatek,pull-down-adv = <10>;
+                   };
+           };
+           ...
+   };
+};
--
1.9.1


_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help