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/*
* 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/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 val_bytes;
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_write16be(struct regmap_mmio_context *ctx,
unsigned int reg,
unsigned int val)
iowrite16be(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);
}
static void regmap_mmio_write32be(struct regmap_mmio_context *ctx,
unsigned int reg,
unsigned int val)
{
iowrite32be(val, ctx->regs + reg);
}
static void regmap_mmio_write64le(struct regmap_mmio_context *ctx,
unsigned int reg,
unsigned int val)
{
writeq(val, ctx->regs + reg);
static int regmap_mmio_write(void *context, unsigned int reg, unsigned int val)
{
struct regmap_mmio_context *ctx = context;
if (!IS_ERR(ctx->clk)) {
ret = clk_enable(ctx->clk);
if (ret < 0)
return ret;
}
ctx->reg_write(ctx, reg, val);
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_read16be(struct regmap_mmio_context *ctx,
unsigned int reg)
{
return ioread16be(ctx->regs + reg);
}
static unsigned int regmap_mmio_read32le(struct regmap_mmio_context *ctx,
unsigned int reg)
{
return readl(ctx->regs + reg);
}
static unsigned int regmap_mmio_read32be(struct regmap_mmio_context *ctx,
unsigned int reg)
{
return ioread32be(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);
static int regmap_mmio_read(void *context, unsigned int reg, unsigned int *val)
{
struct regmap_mmio_context *ctx = context;
if (!IS_ERR(ctx->clk)) {
ret = clk_enable(ctx->clk);
if (ret < 0)
return ret;
}
*val = ctx->reg_read(ctx, reg);
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);
}
static const struct regmap_bus regmap_mmio = {
.reg_write = regmap_mmio_write,
.reg_read = regmap_mmio_read,
.free_context = regmap_mmio_free_context,
};
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;
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 = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return ERR_PTR(-ENOMEM);
ctx->regs = regs;
ctx->val_bytes = config->val_bits / 8;
ctx->clk = ERR_PTR(-ENODEV);
switch (regmap_get_val_endian(dev, ®map_mmio, config)) {
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case REGMAP_ENDIAN_DEFAULT:
case REGMAP_ENDIAN_LITTLE:
#ifdef __LITTLE_ENDIAN
case REGMAP_ENDIAN_NATIVE:
#endif
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;
#ifdef CONFIG_64BIT
case 64:
ctx->reg_read = regmap_mmio_read64le;
ctx->reg_write = regmap_mmio_write64le;
break;
#endif
default:
ret = -EINVAL;
goto err_free;
}
break;
case REGMAP_ENDIAN_BIG:
#ifdef __BIG_ENDIAN
case REGMAP_ENDIAN_NATIVE:
#endif
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_read16be;
ctx->reg_write = regmap_mmio_write16be;
break;
case 32:
ctx->reg_read = regmap_mmio_read32be;
ctx->reg_write = regmap_mmio_write32be;
break;
default:
ret = -EINVAL;
goto err_free;
}
break;
default:
ret = -EINVAL;
goto err_free;
}
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;
}
err_free:
kfree(ctx);
return ERR_PTR(ret);
struct regmap *__regmap_init_mmio_clk(struct device *dev, const char *clk_id,
void __iomem *regs,
const struct regmap_config *config,
struct lock_class_key *lock_key,
const char *lock_name)
{
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,
lock_key, lock_name);
EXPORT_SYMBOL_GPL(__regmap_init_mmio_clk);
struct regmap *__devm_regmap_init_mmio_clk(struct device *dev,
const char *clk_id,
void __iomem *regs,
const struct regmap_config *config,
struct lock_class_key *lock_key,
const char *lock_name)
{
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,
lock_key, lock_name);
EXPORT_SYMBOL_GPL(__devm_regmap_init_mmio_clk);