From afb230077602b5a50f9661bd11b71f678dc2fe34 Mon Sep 17 00:00:00 2001 From: Ahmad Fatoum Date: Tue, 18 Feb 2020 15:23:02 +0100 Subject: regmap: add support for regmap_init_mmio_clk regmap-mmio is used in Linux for clocked memory mapped I/O regions. Port it over, so we can more easily port drivers using it. Signed-off-by: Ahmad Fatoum Signed-off-by: Sascha Hauer --- drivers/base/regmap/Makefile | 3 +- drivers/base/regmap/regmap-mmio.c | 271 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 273 insertions(+), 1 deletion(-) create mode 100644 drivers/base/regmap/regmap-mmio.c (limited to 'drivers/base') diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile index 4dc3d8c510..ab2387037d 100644 --- a/drivers/base/regmap/Makefile +++ b/drivers/base/regmap/Makefile @@ -1 +1,2 @@ -obj-y += regmap.o \ No newline at end of file +obj-y += regmap.o +obj-y += regmap-mmio.o diff --git a/drivers/base/regmap/regmap-mmio.c b/drivers/base/regmap/regmap-mmio.c new file mode 100644 index 0000000000..f8d2cda843 --- /dev/null +++ b/drivers/base/regmap/regmap-mmio.c @@ -0,0 +1,271 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Register map access API - MMIO support +// +// Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved. + +#include +#include +#include +#include + +#include "internal.h" + +struct regmap_mmio_context { + void __iomem *regs; + unsigned val_bytes; + + struct clk *clk; + + void (*reg_write)(struct regmap_mmio_context *ctx, + unsigned int reg, unsigned int val); + unsigned int (*reg_read)(struct regmap_mmio_context *ctx, + unsigned int reg); +}; + +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 int regmap_mmio_get_min_stride(size_t val_bits) +{ + int min_stride; + + switch (val_bits) { + case 8: + /* The core treats 0 as 1 */ + min_stride = 0; + return 0; + case 16: + min_stride = 2; + break; + case 32: + min_stride = 4; + break; +#ifdef CONFIG_64BIT + case 64: + min_stride = 8; + break; +#endif + default: + return -EINVAL; + } + + return min_stride; +} + +static void regmap_mmio_write8(struct regmap_mmio_context *ctx, + unsigned int reg, + unsigned int val) +{ + writeb(val, ctx->regs + reg); +} + +static void regmap_mmio_write16le(struct regmap_mmio_context *ctx, + unsigned int reg, + unsigned int val) +{ + writew(val, ctx->regs + reg); +} + +static void regmap_mmio_write32le(struct regmap_mmio_context *ctx, + unsigned int reg, + unsigned int val) +{ + writel(val, ctx->regs + reg); +} + +#ifdef CONFIG_64BIT +static void regmap_mmio_write64le(struct regmap_mmio_context *ctx, + unsigned int reg, + unsigned int val) +{ + writeq(val, ctx->regs + reg); +} +#endif + +static int regmap_mmio_write(void *context, unsigned int reg, unsigned int val) +{ + struct regmap_mmio_context *ctx = context; + int ret; + + ret = clk_enable(ctx->clk); + if (ret < 0) + return ret; + + ctx->reg_write(ctx, reg, val); + + clk_disable(ctx->clk); + + return 0; +} + +static unsigned int regmap_mmio_read8(struct regmap_mmio_context *ctx, + unsigned int reg) +{ + return readb(ctx->regs + reg); +} + +static unsigned int regmap_mmio_read16le(struct regmap_mmio_context *ctx, + unsigned int reg) +{ + return readw(ctx->regs + reg); +} + +static unsigned int regmap_mmio_read32le(struct regmap_mmio_context *ctx, + unsigned int reg) +{ + return readl(ctx->regs + reg); +} + +#ifdef CONFIG_64BIT +static unsigned int regmap_mmio_read64le(struct regmap_mmio_context *ctx, + unsigned int reg) +{ + return readq(ctx->regs + reg); +} +#endif + +static int regmap_mmio_read(void *context, unsigned int reg, unsigned int *val) +{ + struct regmap_mmio_context *ctx = context; + int ret; + + ret = clk_enable(ctx->clk); + if (ret < 0) + return ret; + + *val = ctx->reg_read(ctx, reg); + + clk_disable(ctx->clk); + + return 0; +} + +static const struct regmap_bus regmap_mmio = { + .reg_write = regmap_mmio_write, + .reg_read = regmap_mmio_read, +}; + +static struct regmap_mmio_context *regmap_mmio_gen_context(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); + + min_stride = regmap_mmio_get_min_stride(config->val_bits); + if (min_stride < 0) + return ERR_PTR(min_stride); + + if (config->reg_stride < min_stride) + return ERR_PTR(-EINVAL); + + ctx = xzalloc(sizeof(*ctx)); + + ctx->regs = regs; + ctx->val_bytes = config->val_bits / 8; + + switch (config->val_bits) { + case 8: + ctx->reg_read = regmap_mmio_read8; + ctx->reg_write = regmap_mmio_write8; + break; + case 16: + ctx->reg_read = regmap_mmio_read16le; + ctx->reg_write = regmap_mmio_write16le; + break; + case 32: + ctx->reg_read = regmap_mmio_read32le; + ctx->reg_write = regmap_mmio_write32le; + break; + default: + ret = -EINVAL; + goto err_free; + } + + return ctx; + +err_free: + kfree(ctx); + + return ERR_PTR(ret); +} + +struct regmap *regmap_init_mmio_clk(struct device_d *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); + if (IS_ERR(ctx)) + return ERR_CAST(ctx); + + if (clk_id) { + ctx->clk = clk_get(dev, clk_id); + if (IS_ERR(ctx->clk)) { + kfree(ctx); + return ERR_CAST(ctx->clk); + } + } + + return regmap_init(dev, ®map_mmio, ctx, config); +} + +struct regmap *of_regmap_init_mmio_clk(struct device_node *np, + const char *clk_id, + void __iomem *regs, + const struct regmap_config *config) +{ + struct regmap_mmio_context *ctx; + + ctx = regmap_mmio_gen_context(regs, config); + if (IS_ERR(ctx)) + return ERR_CAST(ctx); + + if (clk_id) { + ctx->clk = of_clk_get_by_name(np, clk_id); + if (IS_ERR(ctx->clk)) { + kfree(ctx); + return ERR_CAST(ctx->clk); + } + } + + return regmap_init(NULL, ®map_mmio, ctx, config); +} + +int regmap_mmio_attach_clk(struct regmap *map, struct clk *clk) +{ + struct regmap_mmio_context *ctx = map->bus_context; + + ctx->clk = clk; + + return 0; +} + +void regmap_mmio_detach_clk(struct regmap *map) +{ + struct regmap_mmio_context *ctx = map->bus_context; + + ctx->clk = NULL; +} -- cgit v1.2.3