[PATCH] dt-bindings: bus: qcom,ebi2: convert to dtschema
From: Rayyan Ansari
Date: Wed Jul 17 2024 - 09:19:56 EST
Convert the bindings for the External Bus Interface on apq8060 and
msm8660 from the old text format to yaml.
Signed-off-by: Rayyan Ansari <rayyan.ansari@xxxxxxxxxx>
---
.../devicetree/bindings/bus/qcom,ebi2.txt | 138 ----------
.../devicetree/bindings/bus/qcom,ebi2.yaml | 239 ++++++++++++++++++
2 files changed, 239 insertions(+), 138 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/bus/qcom,ebi2.txt
create mode 100644 Documentation/devicetree/bindings/bus/qcom,ebi2.yaml
diff --git a/Documentation/devicetree/bindings/bus/qcom,ebi2.txt b/Documentation/devicetree/bindings/bus/qcom,ebi2.txt
deleted file mode 100644
index 5058aa2c63b2..000000000000
--- a/Documentation/devicetree/bindings/bus/qcom,ebi2.txt
+++ /dev/null
@@ -1,138 +0,0 @@
-Qualcomm External Bus Interface 2 (EBI2)
-
-The EBI2 contains two peripheral blocks: XMEM and LCDC. The XMEM handles any
-external memory (such as NAND or other memory-mapped peripherals) whereas
-LCDC handles LCD displays.
-
-As it says it connects devices to an external bus interface, meaning address
-lines (up to 9 address lines so can only address 1KiB external memory space),
-data lines (16 bits), OE (output enable), ADV (address valid, used on some
-NOR flash memories), WE (write enable). This on top of 6 different chip selects
-(CS0 thru CS5) so that in theory 6 different devices can be connected.
-
-Apparently this bus is clocked at 64MHz. It has dedicated pins on the package
-and the bus can only come out on these pins, however if some of the pins are
-unused they can be left unconnected or remuxed to be used as GPIO or in some
-cases other orthogonal functions as well.
-
-Also CS1 and CS2 has -A and -B signals. Why they have that is unclear to me.
-
-The chip selects have the following memory range assignments. This region of
-memory is referred to as "Chip Peripheral SS FPB0" and is 168MB big.
-
-Chip Select Physical address base
-CS0 GPIO134 0x1a800000-0x1b000000 (8MB)
-CS1 GPIO39 (A) / GPIO123 (B) 0x1b000000-0x1b800000 (8MB)
-CS2 GPIO40 (A) / GPIO124 (B) 0x1b800000-0x1c000000 (8MB)
-CS3 GPIO133 0x1d000000-0x25000000 (128 MB)
-CS4 GPIO132 0x1c800000-0x1d000000 (8MB)
-CS5 GPIO131 0x1c000000-0x1c800000 (8MB)
-
-The APQ8060 Qualcomm Application Processor User Guide, 80-N7150-14 Rev. A,
-August 6, 2012 contains some incomplete documentation of the EBI2.
-
-FIXME: the manual mentions "write precharge cycles" and "precharge cycles".
-We have not been able to figure out which bit fields these correspond to
-in the hardware, or what valid values exist. The current hypothesis is that
-this is something just used on the FAST chip selects and that the SLOW
-chip selects are understood fully. There is also a "byte device enable"
-flag somewhere for 8bit memories.
-
-FIXME: The chipselects have SLOW and FAST configuration registers. It's a bit
-unclear what this means, if they are mutually exclusive or can be used
-together, or if some chip selects are hardwired to be FAST and others are SLOW
-by design.
-
-The XMEM registers are totally undocumented but could be partially decoded
-because the Cypress AN49576 Antioch Westbridge apparently has suspiciously
-similar register layout, see: http://www.cypress.com/file/105771/download
-
-Required properties:
-- compatible: should be one of:
- "qcom,msm8660-ebi2"
- "qcom,apq8060-ebi2"
-- #address-cells: should be <2>: the first cell is the chipselect,
- the second cell is the offset inside the memory range
-- #size-cells: should be <1>
-- ranges: should be set to:
- ranges = <0 0x0 0x1a800000 0x00800000>,
- <1 0x0 0x1b000000 0x00800000>,
- <2 0x0 0x1b800000 0x00800000>,
- <3 0x0 0x1d000000 0x08000000>,
- <4 0x0 0x1c800000 0x00800000>,
- <5 0x0 0x1c000000 0x00800000>;
-- reg: two ranges of registers: EBI2 config and XMEM config areas
-- reg-names: should be "ebi2", "xmem"
-- clocks: two clocks, EBI_2X and EBI
-- clock-names: should be "ebi2x", "ebi2"
-
-Optional subnodes:
-- Nodes inside the EBI2 will be considered device nodes.
-
-The following optional properties are properties that can be tagged onto
-any device subnode. We are assuming that there can be only ONE device per
-chipselect subnode, else the properties will become ambiguous.
-
-Optional properties arrays for SLOW chip selects:
-- qcom,xmem-recovery-cycles: recovery cycles is the time the memory continues to
- drive the data bus after OE is de-asserted, in order to avoid contention on
- the data bus. They are inserted when reading one CS and switching to another
- CS or read followed by write on the same CS. Valid values 0 thru 15. Minimum
- value is actually 1, so a value of 0 will still yield 1 recovery cycle.
-- qcom,xmem-write-hold-cycles: write hold cycles, these are extra cycles
- inserted after every write minimum 1. The data out is driven from the time
- WE is asserted until CS is asserted. With a hold of 1 (value = 0), the CS
- stays active for 1 extra cycle etc. Valid values 0 thru 15.
-- qcom,xmem-write-delta-cycles: initial latency for write cycles inserted for
- the first write to a page or burst memory. Valid values 0 thru 255.
-- qcom,xmem-read-delta-cycles: initial latency for read cycles inserted for the
- first read to a page or burst memory. Valid values 0 thru 255.
-- qcom,xmem-write-wait-cycles: number of wait cycles for every write access, 0=1
- cycle. Valid values 0 thru 15.
-- qcom,xmem-read-wait-cycles: number of wait cycles for every read access, 0=1
- cycle. Valid values 0 thru 15.
-
-Optional properties arrays for FAST chip selects:
-- qcom,xmem-address-hold-enable: this is a boolean property stating that we
- shall hold the address for an extra cycle to meet hold time requirements
- with ADV assertion.
-- qcom,xmem-adv-to-oe-recovery-cycles: the number of cycles elapsed before an OE
- assertion, with respect to the cycle where ADV (address valid) is asserted.
- 2 means 2 cycles between ADV and OE. Valid values 0, 1, 2 or 3.
-- qcom,xmem-read-hold-cycles: the length in cycles of the first segment of a
- read transfer. For a single read transfer this will be the time from CS
- assertion to OE assertion. Valid values 0 thru 15.
-
-
-Example:
-
-ebi2@1a100000 {
- compatible = "qcom,apq8060-ebi2";
- #address-cells = <2>;
- #size-cells = <1>;
- ranges = <0 0x0 0x1a800000 0x00800000>,
- <1 0x0 0x1b000000 0x00800000>,
- <2 0x0 0x1b800000 0x00800000>,
- <3 0x0 0x1d000000 0x08000000>,
- <4 0x0 0x1c800000 0x00800000>,
- <5 0x0 0x1c000000 0x00800000>;
- reg = <0x1a100000 0x1000>, <0x1a110000 0x1000>;
- reg-names = "ebi2", "xmem";
- clocks = <&gcc EBI2_2X_CLK>, <&gcc EBI2_CLK>;
- clock-names = "ebi2x", "ebi2";
- /* Make sure to set up the pin control for the EBI2 */
- pinctrl-names = "default";
- pinctrl-0 = <&foo_ebi2_pins>;
-
- foo-ebi2@2,0 {
- compatible = "foo";
- reg = <2 0x0 0x100>;
- (...)
- qcom,xmem-recovery-cycles = <0>;
- qcom,xmem-write-hold-cycles = <3>;
- qcom,xmem-write-delta-cycles = <31>;
- qcom,xmem-read-delta-cycles = <28>;
- qcom,xmem-write-wait-cycles = <9>;
- qcom,xmem-read-wait-cycles = <9>;
- };
-};
diff --git a/Documentation/devicetree/bindings/bus/qcom,ebi2.yaml b/Documentation/devicetree/bindings/bus/qcom,ebi2.yaml
new file mode 100644
index 000000000000..1b1fb3538e6e
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/qcom,ebi2.yaml
@@ -0,0 +1,239 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/bus/qcom,ebi2.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm External Bus Interface 2 (EBI2)
+
+description: |
+ The EBI2 contains two peripheral blocks: XMEM and LCDC. The XMEM handles any
+ external memory (such as NAND or other memory-mapped peripherals) whereas
+ LCDC handles LCD displays.
+
+ As it says it connects devices to an external bus interface, meaning address
+ lines (up to 9 address lines so can only address 1KiB external memory space),
+ data lines (16 bits), OE (output enable), ADV (address valid, used on some
+ NOR flash memories), WE (write enable). This on top of 6 different chip selects
+ (CS0 thru CS5) so that in theory 6 different devices can be connected.
+
+ Apparently this bus is clocked at 64MHz. It has dedicated pins on the package
+ and the bus can only come out on these pins, however if some of the pins are
+ unused they can be left unconnected or remuxed to be used as GPIO or in some
+ cases other orthogonal functions as well.
+
+ Also CS1 and CS2 has -A and -B signals. Why they have that is unclear to me.
+
+ The chip selects have the following memory range assignments. This region of
+ memory is referred to as "Chip Peripheral SS FPB0" and is 168MB big.
+
+ Chip Select Physical address base
+ CS0 GPIO134 0x1a800000-0x1b000000 (8MB)
+ CS1 GPIO39 (A) / GPIO123 (B) 0x1b000000-0x1b800000 (8MB)
+ CS2 GPIO40 (A) / GPIO124 (B) 0x1b800000-0x1c000000 (8MB)
+ CS3 GPIO133 0x1d000000-0x25000000 (128 MB)
+ CS4 GPIO132 0x1c800000-0x1d000000 (8MB)
+ CS5 GPIO131 0x1c000000-0x1c800000 (8MB)
+
+ The APQ8060 Qualcomm Application Processor User Guide, 80-N7150-14 Rev. A,
+ August 6, 2012 contains some incomplete documentation of the EBI2.
+
+ FIXME: the manual mentions "write precharge cycles" and "precharge cycles".
+ We have not been able to figure out which bit fields these correspond to
+ in the hardware, or what valid values exist. The current hypothesis is that
+ this is something just used on the FAST chip selects and that the SLOW
+ chip selects are understood fully. There is also a "byte device enable"
+ flag somewhere for 8bit memories.
+
+ FIXME: The chipselects have SLOW and FAST configuration registers. It's a bit
+ unclear what this means, if they are mutually exclusive or can be used
+ together, or if some chip selects are hardwired to be FAST and others are SLOW
+ by design.
+
+ The XMEM registers are totally undocumented but could be partially decoded
+ because the Cypress AN49576 Antioch Westbridge apparently has suspiciously
+ similar register layout, see: http://www.cypress.com/file/105771/download
+
+maintainers:
+ - Bjorn Andersson <andersson@xxxxxxxxxx>
+
+properties:
+ compatible:
+ enum:
+ - qcom,apq8060-ebi2
+ - qcom,msm8660-ebi2
+
+ reg:
+ items:
+ - description: EBI2 config region
+ - description: XMEM config region
+
+ reg-names:
+ items:
+ - const: ebi2
+ - const: xmem
+
+ ranges: true
+
+ clocks:
+ items:
+ - description: EBI_2X clock
+ - description: EBI clock
+
+ clock-names:
+ items:
+ - const: ebi2x
+ - const: ebi2
+
+ '#address-cells':
+ const: 2
+
+ '#size-cells':
+ const: 1
+
+required:
+ - compatible
+ - reg
+ - reg-names
+ - ranges
+ - clocks
+ - clock-names
+ - '#address-cells'
+ - '#size-cells'
+
+patternProperties:
+ "^.*@[0-5],[0-9a-f]+$":
+ type: object
+ additionalProperties: true
+ properties:
+ reg:
+ maxItems: 1
+
+ # SLOW chip selects
+ qcom,xmem-recovery-cycles:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: >
+ The time the memory continues to drive the data bus after OE
+ is de-asserted, in order to avoid contention on the data bus.
+ They are inserted when reading one CS and switching to another
+ CS or read followed by write on the same CS. Minimum value is
+ actually 1, so a value of 0 will still yield 1 recovery cycle.
+ minimum: 0
+ maximum: 15
+
+ qcom,xmem-write-hold-cycles:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: >
+ The extra cycles inserted after every write minimum 1. The
+ data out is driven from the time WE is asserted until CS is
+ asserted. With a hold of 1 (value = 0), the CS stays active
+ for 1 extra cycle, etc.
+ minimum: 0
+ maximum: 15
+
+ qcom,xmem-write-delta-cycles:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: >
+ The initial latency for write cycles inserted for the first
+ write to a page or burst memory.
+ minimum: 0
+ maximum: 255
+
+ qcom,xmem-read-delta-cycles:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: >
+ The initial latency for read cycles inserted for the first
+ read to a page or burst memory.
+ minimum: 0
+ maximum: 255
+
+ qcom,xmem-write-wait-cycles:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: >
+ The number of wait cycles for every write access.
+ minimum: 0
+ maximum: 15
+
+ qcom,xmem-read-wait-cycles:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: >
+ The number of wait cycles for every read access.
+ minimum: 0
+ maximum: 15
+
+
+ # FAST chip selects
+ qcom,xmem-address-hold-enable:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: >
+ Holds the address for an extra cycle to meet hold time
+ requirements with ADV assertion, when set to 1.
+ enum: [ 0, 1 ]
+
+ qcom,xmem-adv-to-oe-recovery-cycles:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: >
+ The number of cycles elapsed before an OE assertion, with
+ respect to the cycle where ADV (address valid) is asserted.
+ minimum: 0
+ maximum: 3
+
+ qcom,xmem-read-hold-cycles:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: >
+ The length in cycles of the first segment of a read transfer.
+ For a single read transfer this will be the time from CS
+ assertion to OE assertion.
+ minimum: 0
+ maximum: 15
+
+ required:
+ - reg
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/clock/qcom,gcc-msm8660.h>
+ #include <dt-bindings/interrupt-controller/irq.h>
+ #include <dt-bindings/gpio/gpio.h>
+
+ external-bus@1a100000 {
+ compatible = "qcom,msm8660-ebi2";
+ reg = <0x1a100000 0x1000>, <0x1a110000 0x1000>;
+ reg-names = "ebi2", "xmem";
+ ranges = <0 0x0 0x1a800000 0x00800000>,
+ <1 0x0 0x1b000000 0x00800000>,
+ <2 0x0 0x1b800000 0x00800000>,
+ <3 0x0 0x1d000000 0x08000000>,
+ <4 0x0 0x1c800000 0x00800000>,
+ <5 0x0 0x1c000000 0x00800000>;
+
+ clocks = <&gcc EBI2_2X_CLK>, <&gcc EBI2_CLK>;
+ clock-names = "ebi2x", "ebi2";
+
+ #address-cells = <2>;
+ #size-cells = <1>;
+
+ ethernet@2,0 {
+ compatible = "smsc,lan9221", "smsc,lan9115";
+ reg = <2 0x0 0x100>;
+
+ interrupts-extended = <&pm8058_gpio 7 IRQ_TYPE_EDGE_FALLING>,
+ <&tlmm 29 IRQ_TYPE_EDGE_RISING>;
+ reset-gpios = <&tlmm 30 GPIO_ACTIVE_LOW>;
+
+ phy-mode = "mii";
+ reg-io-width = <2>;
+ smsc,force-external-phy;
+ smsc,irq-push-pull;
+
+ /* SLOW chipselect config */
+ qcom,xmem-recovery-cycles = <0>;
+ qcom,xmem-write-hold-cycles = <3>;
+ qcom,xmem-write-delta-cycles = <31>;
+ qcom,xmem-read-delta-cycles = <28>;
+ qcom,xmem-write-wait-cycles = <9>;
+ qcom,xmem-read-wait-cycles = <9>;
+ };
+ };
--
2.45.2