regmap: Device tree endianness support
This adds generic support for specifying endianess for register map in the DT. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAABAgAGBQJT8g7NAAoJELSic+t+oim9GC0P+wTr8/UEUvvW8tzE4XuyTWSD B+p/LwGe+ZGFxvq8bOpfVpmKzCxKvRRrjoDiKD6MyarssyO4DtSCnlz1tyJyG+Y8 tqyPX8CPe7yZfx1m8I1POt0wYgI1FphLNZ1hsLFzutNSceaQr4++YA6P3046CMl5 LrYeoekpmaIlhkG+3xMxSYamuTPPqANgMgRP63KVxbjxGAxFjMPV5N4+HY1S2kDc M00FwH+hbwx7T10+Rp0saGRKPCJCWwFfvLAjfbGo1O5dIepj92qOKEdmS+b1DrNv 9tjw0cKmKgemzkZotF3mnVSPjm7Rn1MkV8jisbwBXvvZ2P3oI9rbn83Ot8Dw3bzM X77PogFG1wEhQScfBxfyZxFDc02VKmBiZtzxmDjHrHjZKCZm7vdtg1um8N1tboQW 5A1p3IaML4LtXZrk6S6eDlA78ZFC2aSRbsrzLHMftUOwH3/SQZeR11HqenkABDxN J6liiy+AcDhDX+hcYmtqKffbsSyHcK09RfxBKTKunDMeNFsybHea+wbWaXnRsNfv tWTqJipn8anXVgy3j1cIbCd5mixxVCXleCfIzfhzPoPt3DQSWj6gRtjHntWXsN4R OxAc/zi8smirmrD4R9+0n+/E7OJhgSk8OY8tfDAymnyr2r73Q68uCPCGWHcBODeF 2zTxC8Xag7SN08R5WQcJ =5ERR -----END PGP SIGNATURE----- Merge tag 'dt-endian' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap into spi-fsl-dspi regmap: Device tree endianness support This adds generic support for specifying endianess for register map in the DT.
This commit is contained in:
Mark Brown
Коммит
dc8fcd7116
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@ -0,0 +1,47 @@
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Device-Tree binding for regmap
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The endianness mode of CPU & Device scenarios:
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Index Device Endianness properties
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---------------------------------------------------
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1 BE 'big-endian'
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2 LE 'little-endian'
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For one device driver, which will run in different scenarios above
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on different SoCs using the devicetree, we need one way to simplify
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this.
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Required properties:
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- {big,little}-endian: these are boolean properties, if absent
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meaning that the CPU and the Device are in the same endianness mode,
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these properties are for register values and all the buffers only.
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Examples:
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Scenario 1 : CPU in LE mode & device in LE mode.
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dev: dev@40031000 {
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compatible = "name";
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reg = <0x40031000 0x1000>;
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...
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};
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Scenario 2 : CPU in LE mode & device in BE mode.
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dev: dev@40031000 {
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compatible = "name";
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reg = <0x40031000 0x1000>;
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...
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big-endian;
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};
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Scenario 3 : CPU in BE mode & device in BE mode.
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dev: dev@40031000 {
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compatible = "name";
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reg = <0x40031000 0x1000>;
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...
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};
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Scenario 4 : CPU in BE mode & device in LE mode.
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dev: dev@40031000 {
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compatible = "name";
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reg = <0x40031000 0x1000>;
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...
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little-endian;
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};
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@ -168,6 +168,8 @@ static struct regmap_bus regmap_i2c = {
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.write = regmap_i2c_write,
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.gather_write = regmap_i2c_gather_write,
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.read = regmap_i2c_read,
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.reg_format_endian_default = REGMAP_ENDIAN_BIG,
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.val_format_endian_default = REGMAP_ENDIAN_BIG,
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};
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static const struct regmap_bus *regmap_get_i2c_bus(struct i2c_client *i2c,
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@ -109,6 +109,8 @@ static struct regmap_bus regmap_spi = {
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.async_alloc = regmap_spi_async_alloc,
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.read = regmap_spi_read,
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.read_flag_mask = 0x80,
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.reg_format_endian_default = REGMAP_ENDIAN_BIG,
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.val_format_endian_default = REGMAP_ENDIAN_BIG,
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};
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/**
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@ -15,6 +15,7 @@
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#include <linux/export.h>
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#include <linux/mutex.h>
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#include <linux/err.h>
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#include <linux/of.h>
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#include <linux/rbtree.h>
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#include <linux/sched.h>
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@ -448,6 +449,102 @@ int regmap_attach_dev(struct device *dev, struct regmap *map,
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}
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EXPORT_SYMBOL_GPL(regmap_attach_dev);
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enum regmap_endian_type {
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REGMAP_ENDIAN_REG,
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REGMAP_ENDIAN_VAL,
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};
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static int of_regmap_get_endian(struct device *dev,
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const struct regmap_bus *bus,
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const struct regmap_config *config,
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enum regmap_endian_type type,
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enum regmap_endian *endian)
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{
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struct device_node *np = dev->of_node;
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if (!endian || !config)
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return -EINVAL;
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/*
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* Firstly, try to parse the endianness from driver's config,
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* this is to be compatible with the none DT or the old drivers.
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* From the driver's config the endianness value maybe:
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* REGMAP_ENDIAN_BIG,
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* REGMAP_ENDIAN_LITTLE,
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* REGMAP_ENDIAN_NATIVE,
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* REGMAP_ENDIAN_DEFAULT.
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*/
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switch (type) {
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case REGMAP_ENDIAN_REG:
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*endian = config->reg_format_endian;
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break;
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case REGMAP_ENDIAN_VAL:
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*endian = config->val_format_endian;
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break;
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default:
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return -EINVAL;
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}
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/*
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* If the endianness parsed from driver config is
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* REGMAP_ENDIAN_DEFAULT, that means maybe we are using the DT
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* node to specify the endianness information.
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*/
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if (*endian != REGMAP_ENDIAN_DEFAULT)
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return 0;
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/*
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* Secondly, try to parse the endianness from DT node if the
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* driver config does not specify it.
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* From the DT node the endianness value maybe:
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* REGMAP_ENDIAN_BIG,
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* REGMAP_ENDIAN_LITTLE,
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* REGMAP_ENDIAN_NATIVE,
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*/
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switch (type) {
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case REGMAP_ENDIAN_VAL:
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if (of_property_read_bool(np, "big-endian"))
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*endian = REGMAP_ENDIAN_BIG;
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else if (of_property_read_bool(np, "little-endian"))
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*endian = REGMAP_ENDIAN_LITTLE;
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else
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*endian = REGMAP_ENDIAN_NATIVE;
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break;
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case REGMAP_ENDIAN_REG:
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break;
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default:
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return -EINVAL;
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}
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/*
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* If the endianness parsed from DT node is REGMAP_ENDIAN_NATIVE, that
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* maybe means the DT does not care the endianness or it should use
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* the regmap bus's default endianness, then we should try to check
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* whether the regmap bus has specified the default endianness.
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*/
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if (*endian != REGMAP_ENDIAN_NATIVE)
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return 0;
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/*
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* Finally, try to parse the endianness from regmap bus config
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* if in device's DT node the endianness property is absent.
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*/
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switch (type) {
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case REGMAP_ENDIAN_REG:
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if (bus && bus->reg_format_endian_default)
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*endian = bus->reg_format_endian_default;
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break;
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case REGMAP_ENDIAN_VAL:
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if (bus && bus->val_format_endian_default)
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*endian = bus->val_format_endian_default;
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break;
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default:
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return -EINVAL;
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}
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return 0;
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}
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/**
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* regmap_init(): Initialise register map
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*
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@ -551,17 +648,15 @@ struct regmap *regmap_init(struct device *dev,
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map->reg_read = _regmap_bus_read;
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}
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reg_endian = config->reg_format_endian;
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if (reg_endian == REGMAP_ENDIAN_DEFAULT)
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reg_endian = bus->reg_format_endian_default;
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if (reg_endian == REGMAP_ENDIAN_DEFAULT)
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reg_endian = REGMAP_ENDIAN_BIG;
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ret = of_regmap_get_endian(dev, bus, config, REGMAP_ENDIAN_REG,
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®_endian);
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if (ret)
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return ERR_PTR(ret);
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val_endian = config->val_format_endian;
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if (val_endian == REGMAP_ENDIAN_DEFAULT)
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val_endian = bus->val_format_endian_default;
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if (val_endian == REGMAP_ENDIAN_DEFAULT)
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val_endian = REGMAP_ENDIAN_BIG;
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ret = of_regmap_get_endian(dev, bus, config, REGMAP_ENDIAN_VAL,
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&val_endian);
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if (ret)
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return ERR_PTR(ret);
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switch (config->reg_bits + map->reg_shift) {
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case 2:
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