From 878ec67b3ac528a2b6d44055f049cdbb9cfda30c Mon Sep 17 00:00:00 2001 From: Philipp Zabel Date: Thu, 14 Feb 2013 17:39:08 +0100 Subject: [PATCH] regmap: mmio: add register clock support Some mmio devices have a dedicated interface clock that needs to be enabled to access their registers. This patch optionally enables a clock before accessing registers in the regmap_bus callbacks. I added (devm_)regmap_init_mmio_clk variants of the init functions that have an added clk_id string parameter. This is passed to clk_get to request the clock from the clk framework. Signed-off-by: Philipp Zabel Signed-off-by: Mark Brown --- drivers/base/regmap/regmap-mmio.c | 79 ++++++++++++++++++++++++++----- include/linux/regmap.h | 47 +++++++++++++++--- 2 files changed, 107 insertions(+), 19 deletions(-) diff --git a/drivers/base/regmap/regmap-mmio.c b/drivers/base/regmap/regmap-mmio.c index f05fc74dd84a..98745dd77e8c 100644 --- a/drivers/base/regmap/regmap-mmio.c +++ b/drivers/base/regmap/regmap-mmio.c @@ -16,6 +16,7 @@ * along with this program. If not, see . */ +#include #include #include #include @@ -26,6 +27,7 @@ struct regmap_mmio_context { void __iomem *regs; unsigned val_bytes; + struct clk *clk; }; static int regmap_mmio_gather_write(void *context, @@ -34,9 +36,16 @@ static int regmap_mmio_gather_write(void *context, { struct regmap_mmio_context *ctx = context; u32 offset; + int ret; BUG_ON(reg_size != 4); + if (ctx->clk) { + ret = clk_enable(ctx->clk); + if (ret < 0) + return ret; + } + offset = *(u32 *)reg; while (val_size) { @@ -64,6 +73,9 @@ static int regmap_mmio_gather_write(void *context, offset += ctx->val_bytes; } + if (ctx->clk) + clk_disable(ctx->clk); + return 0; } @@ -80,9 +92,16 @@ static int regmap_mmio_read(void *context, { struct regmap_mmio_context *ctx = context; u32 offset; + int ret; BUG_ON(reg_size != 4); + if (ctx->clk) { + ret = clk_enable(ctx->clk); + if (ret < 0) + return ret; + } + offset = *(u32 *)reg; while (val_size) { @@ -110,11 +129,20 @@ static int regmap_mmio_read(void *context, offset += ctx->val_bytes; } + if (ctx->clk) + clk_disable(ctx->clk); + return 0; } static void regmap_mmio_free_context(void *context) { + struct regmap_mmio_context *ctx = context; + + if (ctx->clk) { + clk_unprepare(ctx->clk); + clk_put(ctx->clk); + } kfree(context); } @@ -128,11 +156,14 @@ static struct regmap_bus regmap_mmio = { .val_format_endian_default = REGMAP_ENDIAN_NATIVE, }; -static struct regmap_mmio_context *regmap_mmio_gen_context(void __iomem *regs, +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; if (config->reg_bits != 32) return ERR_PTR(-EINVAL); @@ -179,37 +210,59 @@ static struct regmap_mmio_context *regmap_mmio_gen_context(void __iomem *regs, ctx->regs = regs; ctx->val_bytes = config->val_bits / 8; + 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(): Initialise register map + * 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(struct device *dev, - void __iomem *regs, - const struct regmap_config *config) +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(regs, config); + 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); +EXPORT_SYMBOL_GPL(regmap_init_mmio_clk); /** - * devm_regmap_init_mmio(): Initialise managed register map + * 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 * @@ -217,18 +270,18 @@ EXPORT_SYMBOL_GPL(regmap_init_mmio); * to a struct regmap. The regmap will be automatically freed by the * device management code. */ -struct regmap *devm_regmap_init_mmio(struct device *dev, - void __iomem *regs, - const struct regmap_config *config) +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(regs, config); + 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); +EXPORT_SYMBOL_GPL(devm_regmap_init_mmio_clk); MODULE_LICENSE("GPL v2"); diff --git a/include/linux/regmap.h b/include/linux/regmap.h index b7e95bf942c9..f0480a3297e4 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -285,9 +285,9 @@ struct regmap *regmap_init_i2c(struct i2c_client *i2c, const struct regmap_config *config); struct regmap *regmap_init_spi(struct spi_device *dev, const struct regmap_config *config); -struct regmap *regmap_init_mmio(struct device *dev, - void __iomem *regs, - const struct regmap_config *config); +struct regmap *regmap_init_mmio_clk(struct device *dev, const char *clk_id, + void __iomem *regs, + const struct regmap_config *config); struct regmap *devm_regmap_init(struct device *dev, const struct regmap_bus *bus, @@ -297,9 +297,44 @@ struct regmap *devm_regmap_init_i2c(struct i2c_client *i2c, const struct regmap_config *config); struct regmap *devm_regmap_init_spi(struct spi_device *dev, const struct regmap_config *config); -struct regmap *devm_regmap_init_mmio(struct device *dev, - void __iomem *regs, - const struct regmap_config *config); +struct regmap *devm_regmap_init_mmio_clk(struct device *dev, const char *clk_id, + void __iomem *regs, + const struct regmap_config *config); + +/** + * regmap_init_mmio(): Initialise register map + * + * @dev: Device that will be interacted with + * @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. + */ +static inline struct regmap *regmap_init_mmio(struct device *dev, + void __iomem *regs, + const struct regmap_config *config) +{ + return regmap_init_mmio_clk(dev, NULL, regs, config); +} + +/** + * devm_regmap_init_mmio(): Initialise managed register map + * + * @dev: Device that will be interacted with + * @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. + */ +static inline struct regmap *devm_regmap_init_mmio(struct device *dev, + void __iomem *regs, + const struct regmap_config *config) +{ + return devm_regmap_init_mmio_clk(dev, NULL, regs, config); +} void regmap_exit(struct regmap *map); int regmap_reinit_cache(struct regmap *map, -- 2.30.2