[RFC,v2] regmap: smbus: add support for regmap over SMBus

Message ID	1397480885-11962-1-git-send-email-boris.brezillon@free-electrons.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org> From: Boris BREZILLON <boris.brezillon@free-electrons.com> To: Mark Brown <broonie@kernel.org> Subject: [RFC PATCH v2] regmap: smbus: add support for regmap over SMBus Date: Mon, 14 Apr 2014 15:08:05 +0200 Message-Id: <1397480885-11962-1-git-send-email-boris.brezillon@free-electrons.com> In-Reply-To: <1397292335-5516-1-git-send-email-boris.brezillon@free-electrons.com> References: <1397292335-5516-1-git-send-email-boris.brezillon@free-electrons.com> Cc: Boris BREZILLON <boris.brezillon@free-electrons.com>, dev@linux-sunxi.org, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-kernel@vger.kernel.org, Hans de Goede <hdegoede@redhat.com>, Chen-Yu Tsai <wens@csie.org>, Shuge <shuge@allwinnertech.com>, Maxime Ripard <maxime.ripard@free-electrons.com>, Carlo Caione <carlo@caione.org>, kevin@allwinnertech.com, linux-arm-kernel@lists.infradead.org Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org

diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig index 4251570..450b4c1 100644 --- a/drivers/base/regmap/Kconfig +++ b/drivers/base/regmap/Kconfig @@ -3,7 +3,7 @@ # subsystems should select the appropriate symbols. config REGMAP - default y if (REGMAP_I2C || REGMAP_SPI || REGMAP_SPMI || REGMAP_MMIO || REGMAP_IRQ) + default y if (REGMAP_I2C || REGMAP_SMBUS || REGMAP_SPI || REGMAP_SPMI || REGMAP_MMIO || REGMAP_IRQ) select LZO_COMPRESS select LZO_DECOMPRESS select IRQ_DOMAIN if REGMAP_IRQ @@ -12,6 +12,9 @@ config REGMAP config REGMAP_I2C tristate +config REGMAP_SMBUS + tristate + config REGMAP_SPI tristate diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile index a7c670b..e752b9c 100644 --- a/drivers/base/regmap/Makefile +++ b/drivers/base/regmap/Makefile @@ -2,6 +2,7 @@ obj-$(CONFIG_REGMAP) += regmap.o regcache.o obj-$(CONFIG_REGMAP) += regcache-rbtree.o regcache-lzo.o regcache-flat.o obj-$(CONFIG_DEBUG_FS) += regmap-debugfs.o obj-$(CONFIG_REGMAP_I2C) += regmap-i2c.o +obj-$(CONFIG_REGMAP_SMBUS) += regmap-smbus.o obj-$(CONFIG_REGMAP_SPI) += regmap-spi.o obj-$(CONFIG_REGMAP_SPMI) += regmap-spmi.o obj-$(CONFIG_REGMAP_MMIO) += regmap-mmio.o diff --git a/drivers/base/regmap/regmap-smbus.c b/drivers/base/regmap/regmap-smbus.c new file mode 100644 index 0000000..c8b8075 --- /dev/null +++ b/drivers/base/regmap/regmap-smbus.c @@ -0,0 +1,364 @@ +/* + * Register map access API - SMBus support + * + * Copyright 2014 Free Electrons + * + * Author: Boris Brezillon <boris.brezillon@free-electrons.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/regmap.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/slab.h> + +struct regmap_smbus_context { + struct i2c_client *i2c; + enum regmap_smbus_transfer_type transfer_type; + int val_bytes; +}; + +static int regmap_smbus_write(void *context, const void *data, size_t count) +{ + struct regmap_smbus_context *ctx = context; + int ret = 0; + u8 reg = *(u8 *)data++; + + count--; + + switch (ctx->transfer_type) { + case REGMAP_SMBUS_BYTE_TRANSFER: + while (count > 0 && !ret) { + ret = i2c_smbus_write_byte_data(ctx->i2c, reg++, + *(u8 *)data++); + + count--; + } + break; + + case REGMAP_SMBUS_WORD_TRANSFER: + while (count > 0 && !ret) { + ret = i2c_smbus_write_word_data(ctx->i2c, reg, + *(u16 *)data++); + + reg += 2; + count -= 2; + } + break; + + case REGMAP_SMBUS_BLOCK_TRANSFER: + while (count > 0 && !ret) { + ret = i2c_smbus_write_block_data(ctx->i2c, + reg, + ctx->val_bytes, + (const u8 *)data); + + reg += ctx->val_bytes; + count -= ctx->val_bytes; + data += ctx->val_bytes; + } + break; + + case REGMAP_SMBUS_I2C_BLOCK_TRANSFER: + while (count > 0 && !ret) { + ret = i2c_smbus_write_i2c_block_data(ctx->i2c, + reg, + ctx->val_bytes, + (const u8 *)data); + + reg += ctx->val_bytes; + count -= ctx->val_bytes; + data += ctx->val_bytes; + } + break; + + default: + return -ENOTSUPP; + } + + return ret; +} + +static int regmap_smbus_gather_write(void *context, + const void *reg, size_t reg_size, + const void *val, size_t val_size) +{ + struct regmap_smbus_context *ctx = context; + u8 smbus_reg; + int ret = 0; + + if (reg_size != 1) + return -ENOTSUPP; + + smbus_reg = *(u8 *)reg; + + switch (ctx->transfer_type) { + case REGMAP_SMBUS_BYTE_TRANSFER: + while (val_size && !ret) { + ret = i2c_smbus_write_byte_data(ctx->i2c, + smbus_reg++, + *(u8 *)val++); + + val_size--; + } + break; + + case REGMAP_SMBUS_WORD_TRANSFER: + while (val_size && !ret) { + ret = i2c_smbus_write_word_data(ctx->i2c, + smbus_reg, + *(u16 *)val++); + + smbus_reg += 2; + val_size -= 2; + } + break; + + case REGMAP_SMBUS_BLOCK_TRANSFER: + while (val_size && !ret) { + ret = i2c_smbus_write_block_data(ctx->i2c, + smbus_reg, + ctx->val_bytes, + (const u8 *)val); + + smbus_reg += ctx->val_bytes; + val_size -= ctx->val_bytes; + val += ctx->val_bytes; + } + break; + + case REGMAP_SMBUS_I2C_BLOCK_TRANSFER: + if (val_size > I2C_SMBUS_BLOCK_MAX) + return -ENOTSUPP; + + while (val_size && !ret) { + ret = i2c_smbus_write_i2c_block_data(ctx->i2c, + smbus_reg, + ctx->val_bytes, + (const u8 *)val); + + smbus_reg += ctx->val_bytes; + val_size -= ctx->val_bytes; + val += ctx->val_bytes; + } + break; + + default: + return -ENOTSUPP; + } + + return ret; +} + +static int regmap_smbus_read(void *context, + const void *reg, size_t reg_size, + void *val, size_t val_size) +{ + struct regmap_smbus_context *ctx = context; + u8 buffer[I2C_SMBUS_BLOCK_MAX]; + u8 smbus_reg; + int ret = 0; + + if (reg_size != 1) + return -ENOTSUPP; + + smbus_reg = *(u8 *)reg; + + switch (ctx->transfer_type) { + case REGMAP_SMBUS_BYTE_TRANSFER: + while (val_size && ret >= 0) { + ret = i2c_smbus_read_byte_data(ctx->i2c, smbus_reg++); + if (ret >= 0) + *((u8 *)val++) = ret; + + val_size--; + } + break; + + case REGMAP_SMBUS_WORD_TRANSFER: + while (val_size && ret >= 0) { + ret = i2c_smbus_read_word_data(ctx->i2c, smbus_reg); + if (ret >= 0) + *(u16 *)val++ = ret; + + smbus_reg += 2; + val_size -= 2; + } + break; + + case REGMAP_SMBUS_BLOCK_TRANSFER: + while (val_size && ret >= 0) { + ret = i2c_smbus_read_block_data(ctx->i2c, + smbus_reg, + buffer); + if (ret >= 0 && ret < ctx->val_bytes) { + ret = -EIO; + break; + } + + memcpy(val, buffer, ctx->val_bytes); + smbus_reg += ctx->val_bytes; + val_size -= ctx->val_bytes; + val += ctx->val_bytes; + } + break; + + case REGMAP_SMBUS_I2C_BLOCK_TRANSFER: + while (val_size && ret >= 0) { + return -ENOTSUPP; + + ret = i2c_smbus_read_i2c_block_data(ctx->i2c, + smbus_reg, + ctx->val_bytes, + (u8 *)val); + if (ret >= 0 && ret < val_size) { + ret = -EIO; + break; + } + + smbus_reg += ctx->val_bytes; + val_size -= ctx->val_bytes; + val += ctx->val_bytes; + } + break; + + default: + return -ENOTSUPP; + } + + if (ret < 0) + return ret; + + return 0; +} + +static void regmap_smbus_free_context(void *context) +{ + kfree(context); +} + +struct regmap_smbus_context *regmap_smbus_gen_context(struct i2c_client *i2c, + const struct regmap_config *config, + enum regmap_smbus_transfer_type transfer_type) +{ + struct regmap_smbus_context *ctx; + int val_bytes = 0; + + if (config->reg_bits != 8 || config->pad_bits != 0) + return ERR_PTR(-ENOTSUPP); + + switch (transfer_type) { + case REGMAP_SMBUS_BYTE_TRANSFER: + if (config->val_bits != 8) + return ERR_PTR(-EINVAL); + + if (!i2c_check_functionality(i2c->adapter, + I2C_FUNC_SMBUS_BYTE_DATA)) + return ERR_PTR(-ENOTSUPP); + break; + + case REGMAP_SMBUS_WORD_TRANSFER: + if (config->val_bits != 16) + return ERR_PTR(-EINVAL); + + if (!i2c_check_functionality(i2c->adapter, + I2C_FUNC_SMBUS_WORD_DATA)) + return ERR_PTR(-ENOTSUPP); + break; + + case REGMAP_SMBUS_BLOCK_TRANSFER: + if (config->val_bits > (I2C_SMBUS_BLOCK_MAX * 8)) + return ERR_PTR(-EINVAL); + + val_bytes = DIV_ROUND_UP(config->val_bits, 8); + if (!i2c_check_functionality(i2c->adapter, + I2C_FUNC_SMBUS_BLOCK_DATA)) + return ERR_PTR(-ENOTSUPP); + break; + + case REGMAP_SMBUS_I2C_BLOCK_TRANSFER: + if (config->val_bits > (I2C_SMBUS_BLOCK_MAX * 8)) + return ERR_PTR(-EINVAL); + + val_bytes = DIV_ROUND_UP(config->val_bits, 8); + + if (!i2c_check_functionality(i2c->adapter, + I2C_FUNC_SMBUS_I2C_BLOCK)) + return ERR_PTR(-ENOTSUPP); + break; + + default: + return ERR_PTR(-ENOTSUPP); + } + + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return ERR_PTR(-ENOMEM); + + ctx->i2c = i2c; + ctx->transfer_type = transfer_type; + ctx->val_bytes = val_bytes; + + return ctx; +} + +static struct regmap_bus regmap_smbus = { + .write = regmap_smbus_write, + .gather_write = regmap_smbus_gather_write, + .read = regmap_smbus_read, + .free_context = regmap_smbus_free_context, +}; + +/** + * regmap_init_smbus(): Initialise register map + * + * @i2c: Device that will be interacted with + * @config: Configuration for register map + * @transfer_type: SMBUS transfer type + * + * The return value will be an ERR_PTR() on error or a valid pointer to + * a struct regmap. + */ +struct regmap *regmap_init_smbus(struct i2c_client *i2c, + const struct regmap_config *config, + enum regmap_smbus_transfer_type transfer_type) +{ + struct regmap_smbus_context *ctx = + regmap_smbus_gen_context(i2c, config, transfer_type); + + if (IS_ERR(ctx)) + return ERR_PTR(PTR_ERR(ctx)); + + return regmap_init(&i2c->dev, &regmap_smbus, ctx, config); +} +EXPORT_SYMBOL_GPL(regmap_init_smbus); + +/** + * devm_regmap_init_smbus(): Initialise managed register map + * + * @i2c: Device that will be interacted with + * @config: Configuration for register map + * @transfer_type: SMBUS transfer type + * + * The return value will be an ERR_PTR() on error or a valid pointer + * to a struct regmap. The regmap will be automatically freed by the + * device management code. + */ +struct regmap *devm_regmap_init_smbus(struct i2c_client *i2c, + const struct regmap_config *config, + enum regmap_smbus_transfer_type transfer_type) +{ + struct regmap_smbus_context *ctx = + regmap_smbus_gen_context(i2c, config, transfer_type); + + if (IS_ERR(ctx)) + return ERR_PTR(PTR_ERR(ctx)); + + return devm_regmap_init(&i2c->dev, &regmap_smbus, ctx, config); +} +EXPORT_SYMBOL_GPL(devm_regmap_init_smbus); + +MODULE_LICENSE("GPL"); diff --git a/include/linux/regmap.h b/include/linux/regmap.h index 85691b9..34ef2c7 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -317,6 +317,13 @@ struct regmap_bus { enum regmap_endian val_format_endian_default; }; +enum regmap_smbus_transfer_type { + REGMAP_SMBUS_BYTE_TRANSFER, + REGMAP_SMBUS_WORD_TRANSFER, + REGMAP_SMBUS_BLOCK_TRANSFER, + REGMAP_SMBUS_I2C_BLOCK_TRANSFER, +}; + struct regmap *regmap_init(struct device *dev, const struct regmap_bus *bus, void *bus_context, @@ -325,6 +332,9 @@ int regmap_attach_dev(struct device *dev, struct regmap *map, const struct regmap_config *config); struct regmap *regmap_init_i2c(struct i2c_client *i2c, const struct regmap_config *config); +struct regmap *regmap_init_smbus(struct i2c_client *i2c, + const struct regmap_config *config, + enum regmap_smbus_transfer_type transfer_type); struct regmap *regmap_init_spi(struct spi_device *dev, const struct regmap_config *config); struct regmap *regmap_init_spmi_base(struct spmi_device *dev, @@ -341,6 +351,9 @@ struct regmap *devm_regmap_init(struct device *dev, const struct regmap_config *config); struct regmap *devm_regmap_init_i2c(struct i2c_client *i2c, const struct regmap_config *config); +struct regmap *devm_regmap_init_smbus(struct i2c_client *i2c, + const struct regmap_config *config, + enum regmap_smbus_transfer_type transfer_type); struct regmap *devm_regmap_init_spi(struct spi_device *dev, const struct regmap_config *config); struct regmap *devm_regmap_init_spmi_base(struct spmi_device *dev,

[RFC,v2] regmap: smbus: add support for regmap over SMBus

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