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author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
commit | 57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch) | |
tree | 5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/base/regmap/regmap-mmio.c |
Initial import
Diffstat (limited to 'drivers/base/regmap/regmap-mmio.c')
-rw-r--r-- | drivers/base/regmap/regmap-mmio.c | 350 |
1 files changed, 350 insertions, 0 deletions
diff --git a/drivers/base/regmap/regmap-mmio.c b/drivers/base/regmap/regmap-mmio.c new file mode 100644 index 000000000..04a329a37 --- /dev/null +++ b/drivers/base/regmap/regmap-mmio.c @@ -0,0 +1,350 @@ +/* + * Register map access API - MMIO support + * + * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/regmap.h> +#include <linux/slab.h> + +struct regmap_mmio_context { + void __iomem *regs; + unsigned reg_bytes; + unsigned val_bytes; + unsigned pad_bytes; + struct clk *clk; +}; + +static inline void regmap_mmio_regsize_check(size_t reg_size) +{ + switch (reg_size) { + case 1: + case 2: + case 4: +#ifdef CONFIG_64BIT + case 8: +#endif + break; + default: + BUG(); + } +} + +static int regmap_mmio_regbits_check(size_t reg_bits) +{ + switch (reg_bits) { + case 8: + case 16: + case 32: +#ifdef CONFIG_64BIT + case 64: +#endif + return 0; + default: + return -EINVAL; + } +} + +static inline void regmap_mmio_count_check(size_t count, u32 offset) +{ + BUG_ON(count <= offset); +} + +static inline unsigned int +regmap_mmio_get_offset(const void *reg, size_t reg_size) +{ + switch (reg_size) { + case 1: + return *(u8 *)reg; + case 2: + return *(u16 *)reg; + case 4: + return *(u32 *)reg; +#ifdef CONFIG_64BIT + case 8: + return *(u64 *)reg; +#endif + default: + BUG(); + } +} + +static int regmap_mmio_gather_write(void *context, + const void *reg, size_t reg_size, + const void *val, size_t val_size) +{ + struct regmap_mmio_context *ctx = context; + unsigned int offset; + int ret; + + regmap_mmio_regsize_check(reg_size); + + if (!IS_ERR(ctx->clk)) { + ret = clk_enable(ctx->clk); + if (ret < 0) + return ret; + } + + offset = regmap_mmio_get_offset(reg, reg_size); + + while (val_size) { + switch (ctx->val_bytes) { + case 1: + writeb(*(u8 *)val, ctx->regs + offset); + break; + case 2: + writew(*(u16 *)val, ctx->regs + offset); + break; + case 4: + writel(*(u32 *)val, ctx->regs + offset); + break; +#ifdef CONFIG_64BIT + case 8: + writeq(*(u64 *)val, ctx->regs + offset); + break; +#endif + default: + /* Should be caught by regmap_mmio_check_config */ + BUG(); + } + val_size -= ctx->val_bytes; + val += ctx->val_bytes; + offset += ctx->val_bytes; + } + + if (!IS_ERR(ctx->clk)) + clk_disable(ctx->clk); + + return 0; +} + +static int regmap_mmio_write(void *context, const void *data, size_t count) +{ + struct regmap_mmio_context *ctx = context; + unsigned int offset = ctx->reg_bytes + ctx->pad_bytes; + + regmap_mmio_count_check(count, offset); + + return regmap_mmio_gather_write(context, data, ctx->reg_bytes, + data + offset, count - offset); +} + +static int regmap_mmio_read(void *context, + const void *reg, size_t reg_size, + void *val, size_t val_size) +{ + struct regmap_mmio_context *ctx = context; + unsigned int offset; + int ret; + + regmap_mmio_regsize_check(reg_size); + + if (!IS_ERR(ctx->clk)) { + ret = clk_enable(ctx->clk); + if (ret < 0) + return ret; + } + + offset = regmap_mmio_get_offset(reg, reg_size); + + while (val_size) { + switch (ctx->val_bytes) { + case 1: + *(u8 *)val = readb(ctx->regs + offset); + break; + case 2: + *(u16 *)val = readw(ctx->regs + offset); + break; + case 4: + *(u32 *)val = readl(ctx->regs + offset); + break; +#ifdef CONFIG_64BIT + case 8: + *(u64 *)val = readq(ctx->regs + offset); + break; +#endif + default: + /* Should be caught by regmap_mmio_check_config */ + BUG(); + } + val_size -= ctx->val_bytes; + val += ctx->val_bytes; + offset += ctx->val_bytes; + } + + if (!IS_ERR(ctx->clk)) + clk_disable(ctx->clk); + + return 0; +} + +static void regmap_mmio_free_context(void *context) +{ + struct regmap_mmio_context *ctx = context; + + if (!IS_ERR(ctx->clk)) { + clk_unprepare(ctx->clk); + clk_put(ctx->clk); + } + kfree(context); +} + +static struct regmap_bus regmap_mmio = { + .fast_io = true, + .write = regmap_mmio_write, + .gather_write = regmap_mmio_gather_write, + .read = regmap_mmio_read, + .free_context = regmap_mmio_free_context, + .reg_format_endian_default = REGMAP_ENDIAN_NATIVE, + .val_format_endian_default = REGMAP_ENDIAN_NATIVE, +}; + +static struct regmap_mmio_context *regmap_mmio_gen_context(struct device *dev, + const char *clk_id, + void __iomem *regs, + const struct regmap_config *config) +{ + struct regmap_mmio_context *ctx; + int min_stride; + int ret; + + ret = regmap_mmio_regbits_check(config->reg_bits); + if (ret) + return ERR_PTR(ret); + + if (config->pad_bits) + return ERR_PTR(-EINVAL); + + switch (config->val_bits) { + case 8: + /* The core treats 0 as 1 */ + min_stride = 0; + break; + case 16: + min_stride = 2; + break; + case 32: + min_stride = 4; + break; +#ifdef CONFIG_64BIT + case 64: + min_stride = 8; + break; +#endif + break; + default: + return ERR_PTR(-EINVAL); + } + + if (config->reg_stride < min_stride) + return ERR_PTR(-EINVAL); + + switch (config->reg_format_endian) { + case REGMAP_ENDIAN_DEFAULT: + case REGMAP_ENDIAN_NATIVE: + break; + default: + return ERR_PTR(-EINVAL); + } + + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return ERR_PTR(-ENOMEM); + + ctx->regs = regs; + ctx->val_bytes = config->val_bits / 8; + ctx->reg_bytes = config->reg_bits / 8; + ctx->pad_bytes = config->pad_bits / 8; + ctx->clk = ERR_PTR(-ENODEV); + + if (clk_id == NULL) + return ctx; + + ctx->clk = clk_get(dev, clk_id); + if (IS_ERR(ctx->clk)) { + ret = PTR_ERR(ctx->clk); + goto err_free; + } + + ret = clk_prepare(ctx->clk); + if (ret < 0) { + clk_put(ctx->clk); + goto err_free; + } + + return ctx; + +err_free: + kfree(ctx); + + return ERR_PTR(ret); +} + +/** + * regmap_init_mmio_clk(): Initialise register map with register clock + * + * @dev: Device that will be interacted with + * @clk_id: register clock consumer ID + * @regs: Pointer to memory-mapped IO region + * @config: Configuration for register map + * + * The return value will be an ERR_PTR() on error or a valid pointer to + * a struct regmap. + */ +struct regmap *regmap_init_mmio_clk(struct device *dev, const char *clk_id, + void __iomem *regs, + const struct regmap_config *config) +{ + struct regmap_mmio_context *ctx; + + ctx = regmap_mmio_gen_context(dev, clk_id, regs, config); + if (IS_ERR(ctx)) + return ERR_CAST(ctx); + + return regmap_init(dev, ®map_mmio, ctx, config); +} +EXPORT_SYMBOL_GPL(regmap_init_mmio_clk); + +/** + * devm_regmap_init_mmio_clk(): Initialise managed register map with clock + * + * @dev: Device that will be interacted with + * @clk_id: register clock consumer ID + * @regs: Pointer to memory-mapped IO region + * @config: Configuration for register map + * + * 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_mmio_clk(struct device *dev, const char *clk_id, + void __iomem *regs, + const struct regmap_config *config) +{ + struct regmap_mmio_context *ctx; + + ctx = regmap_mmio_gen_context(dev, clk_id, regs, config); + if (IS_ERR(ctx)) + return ERR_CAST(ctx); + + return devm_regmap_init(dev, ®map_mmio, ctx, config); +} +EXPORT_SYMBOL_GPL(devm_regmap_init_mmio_clk); + +MODULE_LICENSE("GPL v2"); |