- 根目录:
- drivers
- base
- regmap
- regmap-mmio.c
/*
* 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);
}
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);
MODULE_LICENSE("GPL v2");