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regmap: spmi: support base and extended register spaces
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SPMI states that a slave may contain two register spaces, the Base
register space is a 5-bit byte-addressable space accessed via the
Register Read/Write and Register Zero Write command sequences, and the
Extended register space: a 16-bit byte-addressable space accessed via
the Extended Read/Write and Extended Read/Write Long command sequences.

Provide support for accessing both of these spaces, taking advantage of
the more bandwidth-efficient commands ('Register 0 Write' vs 'Register
Write', and 'Extended Register Read/Write' vs 'Extended Register
Read/Write Long') when possible.

Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
Acked-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Josh Cartwright authored and Greg Kroah-Hartman committed Feb 15, 2014
1 parent 2c9e577 commit c9afbb0
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Showing 2 changed files with 205 additions and 35 deletions.
228 changes: 197 additions & 31 deletions drivers/base/regmap/regmap-spmi.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -22,69 +22,235 @@
#include <linux/module.h>
#include <linux/init.h>

static int regmap_spmi_read(void *context,
const void *reg, size_t reg_size,
void *val, size_t val_size)
static int regmap_spmi_base_read(void *context,
const void *reg, size_t reg_size,
void *val, size_t val_size)
{
u8 addr = *(u8 *)reg;
int err = 0;

BUG_ON(reg_size != 1);

while (val_size-- && !err)
err = spmi_register_read(context, addr++, val++);

return err;
}

static int regmap_spmi_base_gather_write(void *context,
const void *reg, size_t reg_size,
const void *val, size_t val_size)
{
const u8 *data = val;
u8 addr = *(u8 *)reg;
int err = 0;

BUG_ON(reg_size != 1);

/*
* SPMI defines a more bandwidth-efficient 'Register 0 Write' sequence,
* use it when possible.
*/
if (addr == 0 && val_size) {
err = spmi_register_zero_write(context, *data);
if (err)
goto err_out;

data++;
addr++;
val_size--;
}

while (val_size) {
err = spmi_register_write(context, addr, *data);
if (err)
goto err_out;

data++;
addr++;
val_size--;
}

err_out:
return err;
}

static int regmap_spmi_base_write(void *context, const void *data,
size_t count)
{
BUG_ON(count < 1);
return regmap_spmi_base_gather_write(context, data, 1, data + 1,
count - 1);
}

static struct regmap_bus regmap_spmi_base = {
.read = regmap_spmi_base_read,
.write = regmap_spmi_base_write,
.gather_write = regmap_spmi_base_gather_write,
.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
};

/**
* regmap_init_spmi_base(): Create regmap for the Base register space
* @sdev: SPMI device that will be interacted with
* @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_spmi_base(struct spmi_device *sdev,
const struct regmap_config *config)
{
return regmap_init(&sdev->dev, &regmap_spmi_base, sdev, config);
}
EXPORT_SYMBOL_GPL(regmap_init_spmi_base);

/**
* devm_regmap_init_spmi_base(): Create managed regmap for Base register space
* @sdev: SPMI device that will be interacted with
* @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_spmi_base(struct spmi_device *sdev,
const struct regmap_config *config)
{
return devm_regmap_init(&sdev->dev, &regmap_spmi_base, sdev, config);
}
EXPORT_SYMBOL_GPL(devm_regmap_init_spmi_base);

static int regmap_spmi_ext_read(void *context,
const void *reg, size_t reg_size,
void *val, size_t val_size)
{
int err = 0;
size_t len;
u16 addr;

BUG_ON(reg_size != 2);
return spmi_ext_register_readl(context, *(u16 *)reg,
val, val_size);

addr = *(u16 *)reg;

/*
* Split accesses into two to take advantage of the more
* bandwidth-efficient 'Extended Register Read' command when possible
*/
while (addr <= 0xFF && val_size) {
len = min_t(size_t, val_size, 16);

err = spmi_ext_register_read(context, addr, val, len);
if (err)
goto err_out;

addr += len;
val += len;
val_size -= len;
}

while (val_size) {
len = min_t(size_t, val_size, 8);

err = spmi_ext_register_readl(context, addr, val, val_size);
if (err)
goto err_out;

addr += len;
val += len;
val_size -= len;
}

err_out:
return err;
}

static int regmap_spmi_gather_write(void *context,
const void *reg, size_t reg_size,
const void *val, size_t val_size)
static int regmap_spmi_ext_gather_write(void *context,
const void *reg, size_t reg_size,
const void *val, size_t val_size)
{
int err = 0;
size_t len;
u16 addr;

BUG_ON(reg_size != 2);
return spmi_ext_register_writel(context, *(u16 *)reg, val, val_size);

addr = *(u16 *)reg;

while (addr <= 0xFF && val_size) {
len = min_t(size_t, val_size, 16);

err = spmi_ext_register_write(context, addr, val, len);
if (err)
goto err_out;

addr += len;
val += len;
val_size -= len;
}

while (val_size) {
len = min_t(size_t, val_size, 8);

err = spmi_ext_register_writel(context, addr, val, len);
if (err)
goto err_out;

addr += len;
val += len;
val_size -= len;
}

err_out:
return err;
}

static int regmap_spmi_write(void *context, const void *data,
size_t count)
static int regmap_spmi_ext_write(void *context, const void *data,
size_t count)
{
BUG_ON(count < 2);
return regmap_spmi_gather_write(context, data, 2, data + 2, count - 2);
return regmap_spmi_ext_gather_write(context, data, 2, data + 2,
count - 2);
}

static struct regmap_bus regmap_spmi = {
.read = regmap_spmi_read,
.write = regmap_spmi_write,
.gather_write = regmap_spmi_gather_write,
static struct regmap_bus regmap_spmi_ext = {
.read = regmap_spmi_ext_read,
.write = regmap_spmi_ext_write,
.gather_write = regmap_spmi_ext_gather_write,
.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
};

/**
* regmap_init_spmi(): Initialize register map
*
* @sdev: Device that will be interacted with
* @config: Configuration for register map
* regmap_init_spmi_ext(): Create regmap for Ext register space
* @sdev: Device that will be interacted with
* @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_spmi(struct spmi_device *sdev,
const struct regmap_config *config)
struct regmap *regmap_init_spmi_ext(struct spmi_device *sdev,
const struct regmap_config *config)
{
return regmap_init(&sdev->dev, &regmap_spmi, sdev, config);
return regmap_init(&sdev->dev, &regmap_spmi_ext, sdev, config);
}
EXPORT_SYMBOL_GPL(regmap_init_spmi);
EXPORT_SYMBOL_GPL(regmap_init_spmi_ext);

/**
* devm_regmap_init_spmi(): Initialise managed register map
*
* @sdev: Device that will be interacted with
* @config: Configuration for register map
* devm_regmap_init_spmi_ext(): Create managed regmap for Ext register space
* @sdev: SPMI device that will be interacted with
* @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_spmi(struct spmi_device *sdev,
struct regmap *devm_regmap_init_spmi_ext(struct spmi_device *sdev,
const struct regmap_config *config)
{
return devm_regmap_init(&sdev->dev, &regmap_spmi, sdev, config);
return devm_regmap_init(&sdev->dev, &regmap_spmi_ext, sdev, config);
}
EXPORT_SYMBOL_GPL(devm_regmap_init_spmi);
EXPORT_SYMBOL_GPL(devm_regmap_init_spmi_ext);

MODULE_LICENSE("GPL");
12 changes: 8 additions & 4 deletions include/linux/regmap.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -321,8 +321,10 @@ 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_spmi(struct spmi_device *dev,
const struct regmap_config *config);
struct regmap *regmap_init_spmi_base(struct spmi_device *dev,
const struct regmap_config *config);
struct regmap *regmap_init_spmi_ext(struct spmi_device *dev,
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);
Expand All @@ -335,8 +337,10 @@ 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_spmi(struct spmi_device *dev,
const struct regmap_config *config);
struct regmap *devm_regmap_init_spmi_base(struct spmi_device *dev,
const struct regmap_config *config);
struct regmap *devm_regmap_init_spmi_ext(struct spmi_device *dev,
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);
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