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-rw-r--r--Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml3
-rw-r--r--Documentation/devicetree/bindings/spi/atmel,quadspi.yaml99
-rw-r--r--Documentation/devicetree/bindings/spi/atmel-quadspi.txt37
-rw-r--r--Documentation/devicetree/bindings/spi/cdns,qspi-nor-peripheral-props.yaml42
-rw-r--r--Documentation/devicetree/bindings/spi/cdns,qspi-nor.yaml33
-rw-r--r--Documentation/devicetree/bindings/spi/mediatek,spi-mtk-nor.yaml8
-rw-r--r--Documentation/devicetree/bindings/spi/renesas,rspi.yaml4
-rw-r--r--Documentation/devicetree/bindings/spi/spi-controller.yaml69
-rw-r--r--Documentation/devicetree/bindings/spi/spi-fsl-lpspi.yaml11
-rw-r--r--Documentation/devicetree/bindings/spi/spi-mux.yaml1
-rw-r--r--Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml89
-rw-r--r--Documentation/devicetree/bindings/spi/spi-pl022.yaml3
-rw-r--r--Documentation/spi/pxa2xx.rst35
-rw-r--r--Documentation/spi/spidev.rst58
14 files changed, 300 insertions, 192 deletions
diff --git a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml
index ed590d7c6e37..39421f7233e4 100644
--- a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml
+++ b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml
@@ -11,6 +11,7 @@ maintainers:
allOf:
- $ref: "mtd.yaml#"
+ - $ref: /schemas/spi/spi-peripheral-props.yaml#
properties:
compatible:
@@ -88,7 +89,7 @@ patternProperties:
"^otp(-[0-9]+)?$":
type: object
-additionalProperties: false
+unevaluatedProperties: false
examples:
- |
diff --git a/Documentation/devicetree/bindings/spi/atmel,quadspi.yaml b/Documentation/devicetree/bindings/spi/atmel,quadspi.yaml
new file mode 100644
index 000000000000..1d493add4053
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/atmel,quadspi.yaml
@@ -0,0 +1,99 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spi/atmel,quadspi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Atmel Quad Serial Peripheral Interface (QSPI)
+
+maintainers:
+ - Tudor Ambarus <tudor.ambarus@microchip.com>
+
+allOf:
+ - $ref: spi-controller.yaml#
+
+properties:
+ compatible:
+ enum:
+ - atmel,sama5d2-qspi
+ - microchip,sam9x60-qspi
+ - microchip,sama7g5-qspi
+ - microchip,sama7g5-ospi
+
+ reg:
+ items:
+ - description: base registers
+ - description: mapped memory
+
+ reg-names:
+ items:
+ - const: qspi_base
+ - const: qspi_mmap
+
+ clocks:
+ minItems: 1
+ items:
+ - description: peripheral clock
+ - description: system clock or generic clock, if available
+
+ clock-names:
+ minItems: 1
+ items:
+ - const: pclk
+ - enum: [ qspick, gclk ]
+
+ interrupts:
+ maxItems: 1
+
+ dmas:
+ items:
+ - description: tx DMA channel
+ - description: rx DMA channel
+
+ dma-names:
+ items:
+ - const: tx
+ - const: rx
+
+ '#address-cells':
+ const: 1
+
+ '#size-cells':
+ const: 0
+
+required:
+ - compatible
+ - reg
+ - reg-names
+ - interrupts
+ - clocks
+ - clock-names
+ - '#address-cells'
+ - '#size-cells'
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/irq.h>
+ #include <dt-bindings/clock/at91.h>
+ spi@f0020000 {
+ compatible = "atmel,sama5d2-qspi";
+ reg = <0xf0020000 0x100>, <0xd0000000 0x8000000>;
+ reg-names = "qspi_base", "qspi_mmap";
+ interrupts = <52 IRQ_TYPE_LEVEL_HIGH 7>;
+ clocks = <&pmc PMC_TYPE_PERIPHERAL 52>;
+ clock-names = "pclk";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_spi0_default>;
+
+ flash@0 {
+ compatible = "jedec,spi-nor";
+ spi-max-frequency = <50000000>;
+ reg = <0>;
+ spi-rx-bus-width = <4>;
+ spi-tx-bus-width = <4>;
+ };
+ };
diff --git a/Documentation/devicetree/bindings/spi/atmel-quadspi.txt b/Documentation/devicetree/bindings/spi/atmel-quadspi.txt
deleted file mode 100644
index 7c40ea694352..000000000000
--- a/Documentation/devicetree/bindings/spi/atmel-quadspi.txt
+++ /dev/null
@@ -1,37 +0,0 @@
-* Atmel Quad Serial Peripheral Interface (QSPI)
-
-Required properties:
-- compatible: Should be one of the following:
- - "atmel,sama5d2-qspi"
- - "microchip,sam9x60-qspi"
-- reg: Should contain the locations and lengths of the base registers
- and the mapped memory.
-- reg-names: Should contain the resource reg names:
- - qspi_base: configuration register address space
- - qspi_mmap: memory mapped address space
-- interrupts: Should contain the interrupt for the device.
-- clocks: Should reference the peripheral clock and the QSPI system
- clock if available.
-- clock-names: Should contain "pclk" for the peripheral clock and "qspick"
- for the system clock when available.
-- #address-cells: Should be <1>.
-- #size-cells: Should be <0>.
-
-Example:
-
-spi@f0020000 {
- compatible = "atmel,sama5d2-qspi";
- reg = <0xf0020000 0x100>, <0xd0000000 0x8000000>;
- reg-names = "qspi_base", "qspi_mmap";
- interrupts = <52 IRQ_TYPE_LEVEL_HIGH 7>;
- clocks = <&pmc PMC_TYPE_PERIPHERAL 52>;
- clock-names = "pclk";
- #address-cells = <1>;
- #size-cells = <0>;
- pinctrl-names = "default";
- pinctrl-0 = <&pinctrl_spi0_default>;
-
- m25p80@0 {
- ...
- };
-};
diff --git a/Documentation/devicetree/bindings/spi/cdns,qspi-nor-peripheral-props.yaml b/Documentation/devicetree/bindings/spi/cdns,qspi-nor-peripheral-props.yaml
new file mode 100644
index 000000000000..553601a441a7
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/cdns,qspi-nor-peripheral-props.yaml
@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spi/cdns,qspi-nor-peripheral-props.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Peripheral-specific properties for the Cadence QSPI controller.
+
+description:
+ See spi-peripheral-props.yaml for more info.
+
+maintainers:
+ - Pratyush Yadav <p.yadav@ti.com>
+
+properties:
+ # cdns,qspi-nor.yaml
+ cdns,read-delay:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Delay for read capture logic, in clock cycles.
+
+ cdns,tshsl-ns:
+ description:
+ Delay in nanoseconds for the length that the master mode chip select
+ outputs are de-asserted between transactions.
+
+ cdns,tsd2d-ns:
+ description:
+ Delay in nanoseconds between one chip select being de-activated
+ and the activation of another.
+
+ cdns,tchsh-ns:
+ description:
+ Delay in nanoseconds between last bit of current transaction and
+ deasserting the device chip select (qspi_n_ss_out).
+
+ cdns,tslch-ns:
+ description:
+ Delay in nanoseconds between setting qspi_n_ss_out low and
+ first bit transfer.
+
+additionalProperties: true
diff --git a/Documentation/devicetree/bindings/spi/cdns,qspi-nor.yaml b/Documentation/devicetree/bindings/spi/cdns,qspi-nor.yaml
index 037f41f58503..0a537fa3a641 100644
--- a/Documentation/devicetree/bindings/spi/cdns,qspi-nor.yaml
+++ b/Documentation/devicetree/bindings/spi/cdns,qspi-nor.yaml
@@ -87,39 +87,6 @@ properties:
items:
enum: [ qspi, qspi-ocp ]
-# subnode's properties
-patternProperties:
- "@[0-9a-f]+$":
- type: object
- description:
- Flash device uses the below defined properties in the subnode.
-
- properties:
- cdns,read-delay:
- $ref: /schemas/types.yaml#/definitions/uint32
- description:
- Delay for read capture logic, in clock cycles.
-
- cdns,tshsl-ns:
- description:
- Delay in nanoseconds for the length that the master mode chip select
- outputs are de-asserted between transactions.
-
- cdns,tsd2d-ns:
- description:
- Delay in nanoseconds between one chip select being de-activated
- and the activation of another.
-
- cdns,tchsh-ns:
- description:
- Delay in nanoseconds between last bit of current transaction and
- deasserting the device chip select (qspi_n_ss_out).
-
- cdns,tslch-ns:
- description:
- Delay in nanoseconds between setting qspi_n_ss_out low and
- first bit transfer.
-
required:
- compatible
- reg
diff --git a/Documentation/devicetree/bindings/spi/mediatek,spi-mtk-nor.yaml b/Documentation/devicetree/bindings/spi/mediatek,spi-mtk-nor.yaml
index 7393f30535df..4e4694e3d539 100644
--- a/Documentation/devicetree/bindings/spi/mediatek,spi-mtk-nor.yaml
+++ b/Documentation/devicetree/bindings/spi/mediatek,spi-mtk-nor.yaml
@@ -43,14 +43,19 @@ properties:
maxItems: 1
clocks:
+ minItems: 2
items:
- description: clock used for spi bus
- description: clock used for controller
+ - description: clock used for nor dma bus. this depends on hardware
+ design, so this is optional.
clock-names:
+ minItems: 2
items:
- const: spi
- const: sf
+ - const: axi
required:
- compatible
@@ -72,7 +77,7 @@ examples:
nor_flash: spi@1100d000 {
compatible = "mediatek,mt8173-nor";
reg = <0 0x1100d000 0 0xe0>;
- interrupts = <&spi_flash_irq>;
+ interrupts = <1>;
clocks = <&pericfg CLK_PERI_SPI>, <&topckgen CLK_TOP_SPINFI_IFR_SEL>;
clock-names = "spi", "sf";
#address-cells = <1>;
@@ -84,4 +89,3 @@ examples:
};
};
};
-
diff --git a/Documentation/devicetree/bindings/spi/renesas,rspi.yaml b/Documentation/devicetree/bindings/spi/renesas,rspi.yaml
index 8397f60d80a2..76e6d9e52fc7 100644
--- a/Documentation/devicetree/bindings/spi/renesas,rspi.yaml
+++ b/Documentation/devicetree/bindings/spi/renesas,rspi.yaml
@@ -21,7 +21,8 @@ properties:
- enum:
- renesas,rspi-r7s72100 # RZ/A1H
- renesas,rspi-r7s9210 # RZ/A2
- - const: renesas,rspi-rz # RZ/A
+ - renesas,r9a07g044-rspi # RZ/G2{L,LC}
+ - const: renesas,rspi-rz # RZ/A and RZ/G2{L,LC}
- items:
- enum:
@@ -122,6 +123,7 @@ allOf:
contains:
enum:
- renesas,qspi
+ - renesas,r9a07g044-rspi
then:
required:
- resets
diff --git a/Documentation/devicetree/bindings/spi/spi-controller.yaml b/Documentation/devicetree/bindings/spi/spi-controller.yaml
index 8246891602e7..36b72518f565 100644
--- a/Documentation/devicetree/bindings/spi/spi-controller.yaml
+++ b/Documentation/devicetree/bindings/spi/spi-controller.yaml
@@ -94,73 +94,8 @@ patternProperties:
"^.*@[0-9a-f]+$":
type: object
- properties:
- compatible:
- description:
- Compatible of the SPI device.
-
- reg:
- minItems: 1
- maxItems: 256
- items:
- minimum: 0
- maximum: 256
- description:
- Chip select used by the device.
-
- spi-3wire:
- $ref: /schemas/types.yaml#/definitions/flag
- description:
- The device requires 3-wire mode.
-
- spi-cpha:
- $ref: /schemas/types.yaml#/definitions/flag
- description:
- The device requires shifted clock phase (CPHA) mode.
-
- spi-cpol:
- $ref: /schemas/types.yaml#/definitions/flag
- description:
- The device requires inverse clock polarity (CPOL) mode.
-
- spi-cs-high:
- $ref: /schemas/types.yaml#/definitions/flag
- description:
- The device requires the chip select active high.
-
- spi-lsb-first:
- $ref: /schemas/types.yaml#/definitions/flag
- description:
- The device requires the LSB first mode.
-
- spi-max-frequency:
- $ref: /schemas/types.yaml#/definitions/uint32
- description:
- Maximum SPI clocking speed of the device in Hz.
-
- spi-rx-bus-width:
- description:
- Bus width to the SPI bus used for read transfers.
- If 0 is provided, then no RX will be possible on this device.
- $ref: /schemas/types.yaml#/definitions/uint32
- enum: [0, 1, 2, 4, 8]
- default: 1
-
- spi-rx-delay-us:
- description:
- Delay, in microseconds, after a read transfer.
-
- spi-tx-bus-width:
- description:
- Bus width to the SPI bus used for write transfers.
- If 0 is provided, then no TX will be possible on this device.
- $ref: /schemas/types.yaml#/definitions/uint32
- enum: [0, 1, 2, 4, 8]
- default: 1
-
- spi-tx-delay-us:
- description:
- Delay, in microseconds, after a write transfer.
+ allOf:
+ - $ref: spi-peripheral-props.yaml
required:
- compatible
diff --git a/Documentation/devicetree/bindings/spi/spi-fsl-lpspi.yaml b/Documentation/devicetree/bindings/spi/spi-fsl-lpspi.yaml
index 312d8fee9dbb..1d46877fe46a 100644
--- a/Documentation/devicetree/bindings/spi/spi-fsl-lpspi.yaml
+++ b/Documentation/devicetree/bindings/spi/spi-fsl-lpspi.yaml
@@ -14,10 +14,13 @@ allOf:
properties:
compatible:
- enum:
- - fsl,imx7ulp-spi
- - fsl,imx8qxp-spi
-
+ oneOf:
+ - enum:
+ - fsl,imx7ulp-spi
+ - fsl,imx8qxp-spi
+ - items:
+ - const: fsl,imx8ulp-spi
+ - const: fsl,imx7ulp-spi
reg:
maxItems: 1
diff --git a/Documentation/devicetree/bindings/spi/spi-mux.yaml b/Documentation/devicetree/bindings/spi/spi-mux.yaml
index 51c7622dc20b..7ea79f6d33f3 100644
--- a/Documentation/devicetree/bindings/spi/spi-mux.yaml
+++ b/Documentation/devicetree/bindings/spi/spi-mux.yaml
@@ -31,6 +31,7 @@ description: |
allOf:
- $ref: "/schemas/spi/spi-controller.yaml#"
+ - $ref: "/schemas/spi/spi-peripheral-props.yaml#"
maintainers:
- Chris Packham <chris.packham@alliedtelesis.co.nz>
diff --git a/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml b/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml
new file mode 100644
index 000000000000..5dd209206e88
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml
@@ -0,0 +1,89 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spi/spi-peripheral-props.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Peripheral-specific properties for a SPI bus.
+
+description:
+ Many SPI controllers need to add properties to peripheral devices. They could
+ be common properties like spi-max-frequency, spi-cpha, etc. or they could be
+ controller specific like delay in clock or data lines, etc. These properties
+ need to be defined in the peripheral node because they are per-peripheral and
+ there can be multiple peripherals attached to a controller. All those
+ properties are listed here. The controller specific properties should go in
+ their own separate schema that should be referenced from here.
+
+maintainers:
+ - Pratyush Yadav <p.yadav@ti.com>
+
+properties:
+ reg:
+ minItems: 1
+ maxItems: 256
+ items:
+ minimum: 0
+ maximum: 256
+ description:
+ Chip select used by the device.
+
+ spi-3wire:
+ $ref: /schemas/types.yaml#/definitions/flag
+ description:
+ The device requires 3-wire mode.
+
+ spi-cpha:
+ $ref: /schemas/types.yaml#/definitions/flag
+ description:
+ The device requires shifted clock phase (CPHA) mode.
+
+ spi-cpol:
+ $ref: /schemas/types.yaml#/definitions/flag
+ description:
+ The device requires inverse clock polarity (CPOL) mode.
+
+ spi-cs-high:
+ $ref: /schemas/types.yaml#/definitions/flag
+ description:
+ The device requires the chip select active high.
+
+ spi-lsb-first:
+ $ref: /schemas/types.yaml#/definitions/flag
+ description:
+ The device requires the LSB first mode.
+
+ spi-max-frequency:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Maximum SPI clocking speed of the device in Hz.
+
+ spi-rx-bus-width:
+ description:
+ Bus width to the SPI bus used for read transfers.
+ If 0 is provided, then no RX will be possible on this device.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ enum: [0, 1, 2, 4, 8]
+ default: 1
+
+ spi-rx-delay-us:
+ description:
+ Delay, in microseconds, after a read transfer.
+
+ spi-tx-bus-width:
+ description:
+ Bus width to the SPI bus used for write transfers.
+ If 0 is provided, then no TX will be possible on this device.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ enum: [0, 1, 2, 4, 8]
+ default: 1
+
+ spi-tx-delay-us:
+ description:
+ Delay, in microseconds, after a write transfer.
+
+# The controller specific properties go here.
+allOf:
+ - $ref: cdns,qspi-nor-peripheral-props.yaml#
+
+additionalProperties: true
diff --git a/Documentation/devicetree/bindings/spi/spi-pl022.yaml b/Documentation/devicetree/bindings/spi/spi-pl022.yaml
index a91d868e40c5..6d633728fc2b 100644
--- a/Documentation/devicetree/bindings/spi/spi-pl022.yaml
+++ b/Documentation/devicetree/bindings/spi/spi-pl022.yaml
@@ -72,6 +72,9 @@ properties:
- const: rx
- const: tx
+ resets:
+ maxItems: 1
+
patternProperties:
"^[a-zA-Z][a-zA-Z0-9,+\\-._]{0,63}@[0-9a-f]+$":
type: object
diff --git a/Documentation/spi/pxa2xx.rst b/Documentation/spi/pxa2xx.rst
index 6312968acfe9..6347580826be 100644
--- a/Documentation/spi/pxa2xx.rst
+++ b/Documentation/spi/pxa2xx.rst
@@ -101,8 +101,7 @@ device. All fields are optional.
u8 rx_threshold;
u8 dma_burst_size;
u32 timeout;
- u8 enable_loopback;
- void (*cs_control)(u32 command);
+ int gpio_cs;
};
The "pxa2xx_spi_chip.tx_threshold" and "pxa2xx_spi_chip.rx_threshold" fields are
@@ -128,16 +127,6 @@ dependent on the SPI bus speed ("spi_board_info.max_speed_hz") and the specific
slave device. Please note that the PXA2xx SSP 1 does not support trailing byte
timeouts and must busy-wait any trailing bytes.
-The "pxa2xx_spi_chip.enable_loopback" field is used to place the SSP porting
-into internal loopback mode. In this mode the SSP controller internally
-connects the SSPTX pin to the SSPRX pin. This is useful for initial setup
-testing.
-
-The "pxa2xx_spi_chip.cs_control" field is used to point to a board specific
-function for asserting/deasserting a slave device chip select. If the field is
-NULL, the pxa2xx_spi master controller driver assumes that the SSP port is
-configured to use GPIO or SSPFRM instead.
-
NOTE: the SPI driver cannot control the chip select if SSPFRM is used, so the
chipselect is dropped after each spi_transfer. Most devices need chip select
asserted around the complete message. Use SSPFRM as a GPIO (through a descriptor)
@@ -152,30 +141,12 @@ field. Below is a sample configuration using the PXA255 NSSP.
::
- /* Chip Select control for the CS8415A SPI slave device */
- static void cs8415a_cs_control(u32 command)
- {
- if (command & PXA2XX_CS_ASSERT)
- GPCR(2) = GPIO_bit(2);
- else
- GPSR(2) = GPIO_bit(2);
- }
-
- /* Chip Select control for the CS8405A SPI slave device */
- static void cs8405a_cs_control(u32 command)
- {
- if (command & PXA2XX_CS_ASSERT)
- GPCR(3) = GPIO_bit(3);
- else
- GPSR(3) = GPIO_bit(3);
- }
-
static struct pxa2xx_spi_chip cs8415a_chip_info = {
.tx_threshold = 8, /* SSP hardward FIFO threshold */
.rx_threshold = 8, /* SSP hardward FIFO threshold */
.dma_burst_size = 8, /* Byte wide transfers used so 8 byte bursts */
.timeout = 235, /* See Intel documentation */
- .cs_control = cs8415a_cs_control, /* Use external chip select */
+ .gpio_cs = 2, /* Use external chip select */
};
static struct pxa2xx_spi_chip cs8405a_chip_info = {
@@ -183,7 +154,7 @@ field. Below is a sample configuration using the PXA255 NSSP.
.rx_threshold = 8, /* SSP hardward FIFO threshold */
.dma_burst_size = 8, /* Byte wide transfers used so 8 byte bursts */
.timeout = 235, /* See Intel documentation */
- .cs_control = cs8405a_cs_control, /* Use external chip select */
+ .gpio_cs = 3, /* Use external chip select */
};
static struct spi_board_info streetracer_spi_board_info[] __initdata = {
diff --git a/Documentation/spi/spidev.rst b/Documentation/spi/spidev.rst
index f05dbc5ccdbc..369c657ba435 100644
--- a/Documentation/spi/spidev.rst
+++ b/Documentation/spi/spidev.rst
@@ -29,21 +29,49 @@ of the driver stack) that are not accessible to userspace.
DEVICE CREATION, DRIVER BINDING
===============================
-The simplest way to arrange to use this driver is to just list it in the
-spi_board_info for a device as the driver it should use: the "modalias"
-entry is "spidev", matching the name of the driver exposing this API.
-Set up the other device characteristics (bits per word, SPI clocking,
-chipselect polarity, etc) as usual, so you won't always need to override
-them later.
-
-(Sysfs also supports userspace driven binding/unbinding of drivers to
-devices. That mechanism might be supported here in the future.)
-
-When you do that, the sysfs node for the SPI device will include a child
-device node with a "dev" attribute that will be understood by udev or mdev.
-(Larger systems will have "udev". Smaller ones may configure "mdev" into
-busybox; it's less featureful, but often enough.) For a SPI device with
-chipselect C on bus B, you should see:
+
+The spidev driver contains lists of SPI devices that are supported for
+the different hardware topology representations.
+
+The following are the SPI device tables supported by the spidev driver:
+
+ - struct spi_device_id spidev_spi_ids[]: list of devices that can be
+ bound when these are defined using a struct spi_board_info with a
+ .modalias field matching one of the entries in the table.
+
+ - struct of_device_id spidev_dt_ids[]: list of devices that can be
+ bound when these are defined using a Device Tree node that has a
+ compatible string matching one of the entries in the table.
+
+ - struct acpi_device_id spidev_acpi_ids[]: list of devices that can
+ be bound when these are defined using a ACPI device object with a
+ _HID matching one of the entries in the table.
+
+You are encouraged to add an entry for your SPI device name to relevant
+tables, if these don't already have an entry for the device. To do that,
+post a patch for spidev to the linux-spi@vger.kernel.org mailing list.
+
+It used to be supported to define an SPI device using the "spidev" name.
+For example, as .modalias = "spidev" or compatible = "spidev". But this
+is no longer supported by the Linux kernel and instead a real SPI device
+name as listed in one of the tables must be used.
+
+Not having a real SPI device name will lead to an error being printed and
+the spidev driver failing to probe.
+
+Sysfs also supports userspace driven binding/unbinding of drivers to
+devices that do not bind automatically using one of the tables above.
+To make the spidev driver bind to such a device, use the following:
+
+ echo spidev > /sys/bus/spi/devices/spiB.C/driver_override
+ echo spiB.C > /sys/bus/spi/drivers/spidev/bind
+
+When the spidev driver is bound to a SPI device, the sysfs node for the
+device will include a child device node with a "dev" attribute that will
+be understood by udev or mdev (udev replacement from BusyBox; it's less
+featureful, but often enough).
+
+For a SPI device with chipselect C on bus B, you should see:
/dev/spidevB.C ...
character special device, major number 153 with