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authorLinus Torvalds <torvalds@linux-foundation.org>2020-06-10 11:03:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-10 11:03:04 -0700
commitc90e7945e3a39c50c07e63a5892e65ecfde374a9 (patch)
tree280390dc674ab02922b3d212018daecf4d607206 /Documentation
parent77d22a4388d33a76180cad69a4309d6636d30855 (diff)
parentbe4cf718cd9929e867ed1ff06d23fb4d08cc2d36 (diff)
Merge tag 'dmaengine-5.8-rc1' of git://git.infradead.org/users/vkoul/slave-dma
Pull dmaengine updates from Vinod Koul: "A fairly small dmaengine update which includes mostly driver updates (dmatest, dw-edma, ioat, mmp-tdma and k3-udma) along with Renesas binding update to json-schema" * tag 'dmaengine-5.8-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (39 commits) dmaengine: imx-sdma: initialize all script addresses dmaengine: ti: k3-udma: Use proper return code in alloc_chan_resources dmaengine: ti: k3-udma: Remove udma_chan.in_ring_cnt dmaengine: ti: k3-udma: Add missing dma_sync call for rx flush descriptor dmaengine: at_xdmac: Replace zero-length array with flexible-array dmaengine: at_hdmac: Replace zero-length array with flexible-array dmaengine: qcom: bam_dma: Replace zero-length array with flexible-array dmaengine: ti: k3-udma: Use PTR_ERR_OR_ZERO() to simplify code dmaengine: moxart-dma: Drop pointless static qualifier in moxart_probe() dmaengine: sf-pdma: Simplify the error handling path in 'sf_pdma_probe()' dmaengine: qcom_hidma: use true,false for bool variable dmaengine: dw-edma: support local dma device transfer semantics dmaengine: Fix doc strings to satisfy validation script dmaengine: Include dmaengine.h into dmaengine.c dmaengine: dmatest: Describe members of struct dmatest_info dmaengine: dmatest: Describe members of struct dmatest_params dmaengine: dmatest: Allow negative timeout value to specify infinite wait Revert "dmaengine: dmatest: timeout value of -1 should specify infinite wait" dmaengine: stm32-dma: direct mode support through device tree dt-bindings: dma: add direct mode support through device tree in stm32-dma ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/stable/sysfs-driver-dma-idxd6
-rw-r--r--Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt117
-rw-r--r--Documentation/devicetree/bindings/dma/renesas,rcar-dmac.yaml150
-rw-r--r--Documentation/devicetree/bindings/dma/renesas,usb-dmac.txt55
-rw-r--r--Documentation/devicetree/bindings/dma/renesas,usb-dmac.yaml102
-rw-r--r--Documentation/devicetree/bindings/dma/st,stm32-dma.yaml5
6 files changed, 263 insertions, 172 deletions
diff --git a/Documentation/ABI/stable/sysfs-driver-dma-idxd b/Documentation/ABI/stable/sysfs-driver-dma-idxd
index f4be46cc6cb6..b5bebf642db6 100644
--- a/Documentation/ABI/stable/sysfs-driver-dma-idxd
+++ b/Documentation/ABI/stable/sysfs-driver-dma-idxd
@@ -1,3 +1,9 @@
+What: sys/bus/dsa/devices/dsa<m>/version
+Date: Apr 15, 2020
+KernelVersion: 5.8.0
+Contact: dmaengine@vger.kernel.org
+Description: The hardware version number.
+
What: sys/bus/dsa/devices/dsa<m>/cdev_major
Date: Oct 25, 2019
KernelVersion: 5.6.0
diff --git a/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt b/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt
deleted file mode 100644
index b7f81c63be8b..000000000000
--- a/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt
+++ /dev/null
@@ -1,117 +0,0 @@
-* Renesas R-Car (RZ/G) DMA Controller Device Tree bindings
-
-Renesas R-Car (Gen 2/3) and RZ/G SoCs have multiple multi-channel DMA
-controller instances named DMAC capable of serving multiple clients. Channels
-can be dedicated to specific clients or shared between a large number of
-clients.
-
-Each DMA client is connected to one dedicated port of the DMAC, identified by
-an 8-bit port number called the MID/RID. A DMA controller can thus serve up to
-256 clients in total. When the number of hardware channels is lower than the
-number of clients to be served, channels must be shared between multiple DMA
-clients. The association of DMA clients to DMAC channels is fully dynamic and
-not described in these device tree bindings.
-
-Required Properties:
-
-- compatible: "renesas,dmac-<soctype>", "renesas,rcar-dmac" as fallback.
- Examples with soctypes are:
- - "renesas,dmac-r8a7743" (RZ/G1M)
- - "renesas,dmac-r8a7744" (RZ/G1N)
- - "renesas,dmac-r8a7745" (RZ/G1E)
- - "renesas,dmac-r8a77470" (RZ/G1C)
- - "renesas,dmac-r8a774a1" (RZ/G2M)
- - "renesas,dmac-r8a774b1" (RZ/G2N)
- - "renesas,dmac-r8a774c0" (RZ/G2E)
- - "renesas,dmac-r8a7790" (R-Car H2)
- - "renesas,dmac-r8a7791" (R-Car M2-W)
- - "renesas,dmac-r8a7792" (R-Car V2H)
- - "renesas,dmac-r8a7793" (R-Car M2-N)
- - "renesas,dmac-r8a7794" (R-Car E2)
- - "renesas,dmac-r8a7795" (R-Car H3)
- - "renesas,dmac-r8a7796" (R-Car M3-W)
- - "renesas,dmac-r8a77961" (R-Car M3-W+)
- - "renesas,dmac-r8a77965" (R-Car M3-N)
- - "renesas,dmac-r8a77970" (R-Car V3M)
- - "renesas,dmac-r8a77980" (R-Car V3H)
- - "renesas,dmac-r8a77990" (R-Car E3)
- - "renesas,dmac-r8a77995" (R-Car D3)
-
-- reg: base address and length of the registers block for the DMAC
-
-- interrupts: interrupt specifiers for the DMAC, one for each entry in
- interrupt-names.
-- interrupt-names: one entry for the error interrupt, named "error", plus one
- entry per channel, named "ch%u", where %u is the channel number ranging from
- zero to the number of channels minus one.
-
-- clock-names: "fck" for the functional clock
-- clocks: a list of phandle + clock-specifier pairs, one for each entry
- in clock-names.
-- clock-names: must contain "fck" for the functional clock.
-
-- #dma-cells: must be <1>, the cell specifies the MID/RID of the DMAC port
- connected to the DMA client
-- dma-channels: number of DMA channels
-
-Example: R8A7790 (R-Car H2) SYS-DMACs
-
- dmac0: dma-controller@e6700000 {
- compatible = "renesas,dmac-r8a7790", "renesas,rcar-dmac";
- reg = <0 0xe6700000 0 0x20000>;
- interrupts = <0 197 IRQ_TYPE_LEVEL_HIGH
- 0 200 IRQ_TYPE_LEVEL_HIGH
- 0 201 IRQ_TYPE_LEVEL_HIGH
- 0 202 IRQ_TYPE_LEVEL_HIGH
- 0 203 IRQ_TYPE_LEVEL_HIGH
- 0 204 IRQ_TYPE_LEVEL_HIGH
- 0 205 IRQ_TYPE_LEVEL_HIGH
- 0 206 IRQ_TYPE_LEVEL_HIGH
- 0 207 IRQ_TYPE_LEVEL_HIGH
- 0 208 IRQ_TYPE_LEVEL_HIGH
- 0 209 IRQ_TYPE_LEVEL_HIGH
- 0 210 IRQ_TYPE_LEVEL_HIGH
- 0 211 IRQ_TYPE_LEVEL_HIGH
- 0 212 IRQ_TYPE_LEVEL_HIGH
- 0 213 IRQ_TYPE_LEVEL_HIGH
- 0 214 IRQ_TYPE_LEVEL_HIGH>;
- interrupt-names = "error",
- "ch0", "ch1", "ch2", "ch3",
- "ch4", "ch5", "ch6", "ch7",
- "ch8", "ch9", "ch10", "ch11",
- "ch12", "ch13", "ch14";
- clocks = <&mstp2_clks R8A7790_CLK_SYS_DMAC0>;
- clock-names = "fck";
- #dma-cells = <1>;
- dma-channels = <15>;
- };
-
- dmac1: dma-controller@e6720000 {
- compatible = "renesas,dmac-r8a7790", "renesas,rcar-dmac";
- reg = <0 0xe6720000 0 0x20000>;
- interrupts = <0 220 IRQ_TYPE_LEVEL_HIGH
- 0 216 IRQ_TYPE_LEVEL_HIGH
- 0 217 IRQ_TYPE_LEVEL_HIGH
- 0 218 IRQ_TYPE_LEVEL_HIGH
- 0 219 IRQ_TYPE_LEVEL_HIGH
- 0 308 IRQ_TYPE_LEVEL_HIGH
- 0 309 IRQ_TYPE_LEVEL_HIGH
- 0 310 IRQ_TYPE_LEVEL_HIGH
- 0 311 IRQ_TYPE_LEVEL_HIGH
- 0 312 IRQ_TYPE_LEVEL_HIGH
- 0 313 IRQ_TYPE_LEVEL_HIGH
- 0 314 IRQ_TYPE_LEVEL_HIGH
- 0 315 IRQ_TYPE_LEVEL_HIGH
- 0 316 IRQ_TYPE_LEVEL_HIGH
- 0 317 IRQ_TYPE_LEVEL_HIGH
- 0 318 IRQ_TYPE_LEVEL_HIGH>;
- interrupt-names = "error",
- "ch0", "ch1", "ch2", "ch3",
- "ch4", "ch5", "ch6", "ch7",
- "ch8", "ch9", "ch10", "ch11",
- "ch12", "ch13", "ch14";
- clocks = <&mstp2_clks R8A7790_CLK_SYS_DMAC1>;
- clock-names = "fck";
- #dma-cells = <1>;
- dma-channels = <15>;
- };
diff --git a/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.yaml b/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.yaml
new file mode 100644
index 000000000000..b842dfd96a89
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.yaml
@@ -0,0 +1,150 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/dma/renesas,rcar-dmac.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas R-Car and RZ/G DMA Controller
+
+maintainers:
+ - Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
+
+allOf:
+ - $ref: "dma-controller.yaml#"
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - renesas,dmac-r8a7743 # RZ/G1M
+ - renesas,dmac-r8a7744 # RZ/G1N
+ - renesas,dmac-r8a7745 # RZ/G1E
+ - renesas,dmac-r8a77470 # RZ/G1C
+ - renesas,dmac-r8a774a1 # RZ/G2M
+ - renesas,dmac-r8a774b1 # RZ/G2N
+ - renesas,dmac-r8a774c0 # RZ/G2E
+ - renesas,dmac-r8a7790 # R-Car H2
+ - renesas,dmac-r8a7791 # R-Car M2-W
+ - renesas,dmac-r8a7792 # R-Car V2H
+ - renesas,dmac-r8a7793 # R-Car M2-N
+ - renesas,dmac-r8a7794 # R-Car E2
+ - renesas,dmac-r8a7795 # R-Car H3
+ - renesas,dmac-r8a7796 # R-Car M3-W
+ - renesas,dmac-r8a77961 # R-Car M3-W+
+ - renesas,dmac-r8a77965 # R-Car M3-N
+ - renesas,dmac-r8a77970 # R-Car V3M
+ - renesas,dmac-r8a77980 # R-Car V3H
+ - renesas,dmac-r8a77990 # R-Car E3
+ - renesas,dmac-r8a77995 # R-Car D3
+ - const: renesas,rcar-dmac
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ minItems: 9
+ maxItems: 17
+
+ interrupt-names:
+ minItems: 9
+ maxItems: 17
+ items:
+ - const: error
+ - pattern: "^ch([0-9]|1[0-5])$"
+ - pattern: "^ch([0-9]|1[0-5])$"
+ - pattern: "^ch([0-9]|1[0-5])$"
+ - pattern: "^ch([0-9]|1[0-5])$"
+ - pattern: "^ch([0-9]|1[0-5])$"
+ - pattern: "^ch([0-9]|1[0-5])$"
+ - pattern: "^ch([0-9]|1[0-5])$"
+ - pattern: "^ch([0-9]|1[0-5])$"
+ - pattern: "^ch([0-9]|1[0-5])$"
+ - pattern: "^ch([0-9]|1[0-5])$"
+ - pattern: "^ch([0-9]|1[0-5])$"
+ - pattern: "^ch([0-9]|1[0-5])$"
+ - pattern: "^ch([0-9]|1[0-5])$"
+ - pattern: "^ch([0-9]|1[0-5])$"
+ - pattern: "^ch([0-9]|1[0-5])$"
+ - pattern: "^ch([0-9]|1[0-5])$"
+
+ clocks:
+ maxItems: 1
+
+ clock-names:
+ maxItems: 1
+ items:
+ - const: fck
+
+ '#dma-cells':
+ const: 1
+ description:
+ The cell specifies the MID/RID of the DMAC port connected to
+ the DMA client.
+
+ dma-channels:
+ minimum: 8
+ maximum: 16
+
+ dma-channel-mask: true
+
+ iommus:
+ minItems: 8
+ maxItems: 16
+
+ power-domains:
+ maxItems: 1
+
+ resets:
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+ - interrupts
+ - interrupt-names
+ - clocks
+ - clock-names
+ - '#dma-cells'
+ - dma-channels
+ - power-domains
+ - resets
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/clock/r8a7790-cpg-mssr.h>
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ #include <dt-bindings/power/r8a7790-sysc.h>
+
+ dmac0: dma-controller@e6700000 {
+ compatible = "renesas,dmac-r8a7790", "renesas,rcar-dmac";
+ reg = <0xe6700000 0x20000>;
+ interrupts = <GIC_SPI 197 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 200 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 201 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 202 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 203 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 204 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 205 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 206 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 207 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 208 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 209 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 210 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 211 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 212 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 213 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 214 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-names = "error",
+ "ch0", "ch1", "ch2", "ch3",
+ "ch4", "ch5", "ch6", "ch7",
+ "ch8", "ch9", "ch10", "ch11",
+ "ch12", "ch13", "ch14";
+ clocks = <&cpg CPG_MOD 219>;
+ clock-names = "fck";
+ power-domains = <&sysc R8A7790_PD_ALWAYS_ON>;
+ resets = <&cpg 219>;
+ #dma-cells = <1>;
+ dma-channels = <15>;
+ };
diff --git a/Documentation/devicetree/bindings/dma/renesas,usb-dmac.txt b/Documentation/devicetree/bindings/dma/renesas,usb-dmac.txt
deleted file mode 100644
index e8f6c42e80f2..000000000000
--- a/Documentation/devicetree/bindings/dma/renesas,usb-dmac.txt
+++ /dev/null
@@ -1,55 +0,0 @@
-* Renesas USB DMA Controller Device Tree bindings
-
-Required Properties:
--compatible: "renesas,<soctype>-usb-dmac", "renesas,usb-dmac" as fallback.
- Examples with soctypes are:
- - "renesas,r8a7743-usb-dmac" (RZ/G1M)
- - "renesas,r8a7744-usb-dmac" (RZ/G1N)
- - "renesas,r8a7745-usb-dmac" (RZ/G1E)
- - "renesas,r8a77470-usb-dmac" (RZ/G1C)
- - "renesas,r8a774a1-usb-dmac" (RZ/G2M)
- - "renesas,r8a774b1-usb-dmac" (RZ/G2N)
- - "renesas,r8a774c0-usb-dmac" (RZ/G2E)
- - "renesas,r8a7790-usb-dmac" (R-Car H2)
- - "renesas,r8a7791-usb-dmac" (R-Car M2-W)
- - "renesas,r8a7793-usb-dmac" (R-Car M2-N)
- - "renesas,r8a7794-usb-dmac" (R-Car E2)
- - "renesas,r8a7795-usb-dmac" (R-Car H3)
- - "renesas,r8a7796-usb-dmac" (R-Car M3-W)
- - "renesas,r8a77961-usb-dmac" (R-Car M3-W+)
- - "renesas,r8a77965-usb-dmac" (R-Car M3-N)
- - "renesas,r8a77990-usb-dmac" (R-Car E3)
- - "renesas,r8a77995-usb-dmac" (R-Car D3)
-- reg: base address and length of the registers block for the DMAC
-- interrupts: interrupt specifiers for the DMAC, one for each entry in
- interrupt-names.
-- interrupt-names: one entry per channel, named "ch%u", where %u is the
- channel number ranging from zero to the number of channels minus one.
-- clocks: a list of phandle + clock-specifier pairs.
-- #dma-cells: must be <1>, the cell specifies the channel number of the DMAC
- port connected to the DMA client.
-- dma-channels: number of DMA channels
-
-Example: R8A7790 (R-Car H2) USB-DMACs
-
- usb_dmac0: dma-controller@e65a0000 {
- compatible = "renesas,r8a7790-usb-dmac", "renesas,usb-dmac";
- reg = <0 0xe65a0000 0 0x100>;
- interrupts = <0 109 IRQ_TYPE_LEVEL_HIGH
- 0 109 IRQ_TYPE_LEVEL_HIGH>;
- interrupt-names = "ch0", "ch1";
- clocks = <&mstp3_clks R8A7790_CLK_USBDMAC0>;
- #dma-cells = <1>;
- dma-channels = <2>;
- };
-
- usb_dmac1: dma-controller@e65b0000 {
- compatible = "renesas,usb-dmac";
- reg = <0 0xe65b0000 0 0x100>;
- interrupts = <0 110 IRQ_TYPE_LEVEL_HIGH
- 0 110 IRQ_TYPE_LEVEL_HIGH>;
- interrupt-names = "ch0", "ch1";
- clocks = <&mstp3_clks R8A7790_CLK_USBDMAC1>;
- #dma-cells = <1>;
- dma-channels = <2>;
- };
diff --git a/Documentation/devicetree/bindings/dma/renesas,usb-dmac.yaml b/Documentation/devicetree/bindings/dma/renesas,usb-dmac.yaml
new file mode 100644
index 000000000000..9ca6d8ddf232
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/renesas,usb-dmac.yaml
@@ -0,0 +1,102 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/dma/renesas,usb-dmac.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas USB DMA Controller
+
+maintainers:
+ - Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
+
+allOf:
+ - $ref: "dma-controller.yaml#"
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - renesas,r8a7743-usb-dmac # RZ/G1M
+ - renesas,r8a7744-usb-dmac # RZ/G1N
+ - renesas,r8a7745-usb-dmac # RZ/G1E
+ - renesas,r8a77470-usb-dmac # RZ/G1C
+ - renesas,r8a774a1-usb-dmac # RZ/G2M
+ - renesas,r8a774b1-usb-dmac # RZ/G2N
+ - renesas,r8a774c0-usb-dmac # RZ/G2E
+ - renesas,r8a7790-usb-dmac # R-Car H2
+ - renesas,r8a7791-usb-dmac # R-Car M2-W
+ - renesas,r8a7793-usb-dmac # R-Car M2-N
+ - renesas,r8a7794-usb-dmac # R-Car E2
+ - renesas,r8a7795-usb-dmac # R-Car H3
+ - renesas,r8a7796-usb-dmac # R-Car M3-W
+ - renesas,r8a77961-usb-dmac # R-Car M3-W+
+ - renesas,r8a77965-usb-dmac # R-Car M3-N
+ - renesas,r8a77990-usb-dmac # R-Car E3
+ - renesas,r8a77995-usb-dmac # R-Car D3
+ - const: renesas,usb-dmac
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ minItems: 2
+ maxItems: 2
+
+ interrupt-names:
+ items:
+ - pattern: ch0
+ - pattern: ch1
+
+ clocks:
+ maxItems: 1
+
+ '#dma-cells':
+ const: 1
+ description:
+ The cell specifies the channel number of the DMAC port connected to
+ the DMA client.
+
+ dma-channels:
+ const: 2
+
+ iommus:
+ minItems: 2
+ maxItems: 2
+
+ power-domains:
+ maxItems: 1
+
+ resets:
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+ - interrupts
+ - interrupt-names
+ - clocks
+ - '#dma-cells'
+ - dma-channels
+ - power-domains
+ - resets
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/clock/r8a7790-cpg-mssr.h>
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ #include <dt-bindings/power/r8a7790-sysc.h>
+
+ usb_dmac0: dma-controller@e65a0000 {
+ compatible = "renesas,r8a7790-usb-dmac", "renesas,usb-dmac";
+ reg = <0xe65a0000 0x100>;
+ interrupts = <GIC_SPI 109 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 109 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-names = "ch0", "ch1";
+ clocks = <&cpg CPG_MOD 330>;
+ power-domains = <&sysc R8A7790_PD_ALWAYS_ON>;
+ resets = <&cpg 330>;
+ #dma-cells = <1>;
+ dma-channels = <2>;
+ };
diff --git a/Documentation/devicetree/bindings/dma/st,stm32-dma.yaml b/Documentation/devicetree/bindings/dma/st,stm32-dma.yaml
index 0c0ac11ad55f..71987878e4ae 100644
--- a/Documentation/devicetree/bindings/dma/st,stm32-dma.yaml
+++ b/Documentation/devicetree/bindings/dma/st,stm32-dma.yaml
@@ -36,6 +36,11 @@ description: |
0x1: 1/2 full FIFO
0x2: 3/4 full FIFO
0x3: full FIFO
+ -bit 2: DMA direct mode
+ 0x0: FIFO mode with threshold selectable with bit 0-1
+ 0x1: Direct mode: each DMA request immediately initiates a transfer
+ from/to the memory, FIFO is bypassed.
+
maintainers:
- Amelie Delaunay <amelie.delaunay@st.com>