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authorLinus Torvalds <torvalds@linux-foundation.org>2017-11-13 20:43:24 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-13 20:43:24 +0300
commite75427c6945460c36bfcab4cd33db0adc0e17200 (patch)
treeb6ffdc7b7a7de951681e900ee0ce7c405864b4b3 /Documentation/devicetree/bindings/spi/spi-sprd-adi.txt
parent5f194bf4853bcb6e7442518b70fb20a875ed34f0 (diff)
parentabbdb5ce31c21a4b3c3922c56030f3d487497933 (diff)
downloadlinux-e75427c6945460c36bfcab4cd33db0adc0e17200.tar.xz
Merge tag 'spi-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
Pull spi updates from Mark Brown: "This release is almost entirely driver changes, there's a couple of fixes in the core but otherwise it's all drivers: - fix for mixed dynamic and static bus number assignment. - fixes for some leaks arising from confusing lifetime rules during device unregistration and improved documentation to try to help avoid this in the future. - fixes to make the native chip select support for i.MX usable. - slave mode support for i.MX. - support for Coldfire MCF5441x DSPI, Renesas R8A7443/5 and Spreadtrum ADI" * tag 'spi-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (31 commits) spi: imx: Don't require platform data chipselect array spi: imx: Fix failure path leak on GPIO request error spi: imx: GPIO based chip selects should not be required spi: sh-msiof: remove redundant pointer dev spi: s3c64xx: remove redundant pointer sci spi: spi-fsl-dspi: enabling Coldfire mcf5441x dspi spi: fix IDR collision on systems with both fixed and dynamic SPI bus numbers spi: orion: remove redundant assignment of status to zero spi: sh-msiof: Fix DMA transfer size check spi: imx: Fix failure path leak on GPIO request error spi: spi-axi: fix potential use-after-free after deregistration spi: document odd controller reference handling spi: fix use-after-free at controller deregistration spi: sprd: Fix the possible negative value of BIT() spi: sprd-adi: fix platform_no_drv_owner.cocci warnings spi: a3700: Change SPI mode before asserting chip-select spi: tegra114: correct register name in definition spi: spreadtrum adi: add hwspinlock dependency spi: sh-msiof: Use of_device_get_match_data() helper spi: rspi: Use of_device_get_match_data() helper ...
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+Spreadtrum ADI controller
+
+ADI is the abbreviation of Anolog-Digital interface, which is used to access
+analog chip (such as PMIC) from digital chip. ADI controller follows the SPI
+framework for its hardware implementation is alike to SPI bus and its timing
+is compatile to SPI timing.
+
+ADI controller has 50 channels including 2 software read/write channels and
+48 hardware channels to access analog chip. For 2 software read/write channels,
+users should set ADI registers to access analog chip. For hardware channels,
+we can configure them to allow other hardware components to use it independently,
+which means we can just link one analog chip address to one hardware channel,
+then users can access the mapped analog chip address by this hardware channel
+triggered by hardware components instead of ADI software channels.
+
+Thus we introduce one property named "sprd,hw-channels" to configure hardware
+channels, the first value specifies the hardware channel id which is used to
+transfer data triggered by hardware automatically, and the second value specifies
+the analog chip address where user want to access by hardware components.
+
+Since we have multi-subsystems will use unique ADI to access analog chip, when
+one system is reading/writing data by ADI software channels, that should be under
+one hardware spinlock protection to prevent other systems from reading/writing
+data by ADI software channels at the same time, or two parallel routine of setting
+ADI registers will make ADI controller registers chaos to lead incorrect results.
+Then we need one hardware spinlock to synchronize between the multiple subsystems.
+
+Required properties:
+- compatible: Should be "sprd,sc9860-adi".
+- reg: Offset and length of ADI-SPI controller register space.
+- hwlocks: Reference to a phandle of a hwlock provider node.
+- hwlock-names: Reference to hwlock name strings defined in the same order
+ as the hwlocks, should be "adi".
+- #address-cells: Number of cells required to define a chip select address
+ on the ADI-SPI bus. Should be set to 1.
+- #size-cells: Size of cells required to define a chip select address size
+ on the ADI-SPI bus. Should be set to 0.
+
+Optional properties:
+- sprd,hw-channels: This is an array of channel values up to 49 channels.
+ The first value specifies the hardware channel id which is used to
+ transfer data triggered by hardware automatically, and the second
+ value specifies the analog chip address where user want to access
+ by hardware components.
+
+SPI slave nodes must be children of the SPI controller node and can contain
+properties described in Documentation/devicetree/bindings/spi/spi-bus.txt.
+
+Example:
+ adi_bus: spi@40030000 {
+ compatible = "sprd,sc9860-adi";
+ reg = <0 0x40030000 0 0x10000>;
+ hwlocks = <&hwlock1 0>;
+ hwlock-names = "adi";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ sprd,hw-channels = <30 0x8c20>;
+ };