Add helpers zl3073x_{read,write}_reg() to access device registers.
These functions have to be called with device lock that can be taken
by zl3073x_{lock,unlock}() or a caller can use defined guard.Reviewed-by: Michal Schmidt <[email protected]> Signed-off-by: Ivan Vecera <[email protected]> --- drivers/mfd/zl3073x-core.c | 88 +++++++++++++++++++++++++++++++++++++ include/linux/mfd/zl3073x.h | 32 ++++++++++++++ 2 files changed, 120 insertions(+) diff --git a/drivers/mfd/zl3073x-core.c b/drivers/mfd/zl3073x-core.c index 71454f683eab0..39d4c8608a740 100644 --- a/drivers/mfd/zl3073x-core.c +++ b/drivers/mfd/zl3073x-core.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0-only #include <linux/module.h> +#include <linux/unaligned.h> #include <net/devlink.h> #include "zl3073x.h" @@ -45,6 +46,93 @@ const struct regmap_config *zl3073x_get_regmap_config(void) } EXPORT_SYMBOL_NS_GPL(zl3073x_get_regmap_config, "ZL3073X"); +/** + * zl3073x_read_reg - Read value from device register + * @zldev: device structure pointer + * @reg: register to be read + * @len: number of bytes to read + * @value: pointer to place to store value read from the register + * + * Caller has to hold the device lock that can be obtained + * by zl3073x_lock(). + * + * Returns 0 in case of success or negative value otherwise + */ +int zl3073x_read_reg(struct zl3073x_dev *zldev, unsigned int reg, + unsigned int len, void *value) +{ + u8 buf[6]; + int rc; + + lockdep_assert_held(&zldev->lock); + + rc = regmap_bulk_read(zldev->regmap, reg, buf, len); + if (rc) + return rc; + + switch (len) { + case 1: + *(u8 *)value = buf[0]; + break; + case 2: + *(u16 *)value = get_unaligned_be16(buf); + break; + case 4: + *(u32 *)value = get_unaligned_be32(buf); + break; + case 6: + *(u64 *)value = get_unaligned_be48(buf); + break; + default: + WARN(true, "Unsupported register size: %u\n", len); + break; + } + + return rc; +} +EXPORT_SYMBOL_GPL(zl3073x_read_reg); + +/** + * zl3073x_write_reg - Write value to device register + * @zldev: device structure pointer + * @reg: register to be written + * @len: number of bytes to write + * @value: pointer to value to write to the register + * + * Caller has to hold the device lock that can be obtained + * by zl3073x_lock(). + * + * Returns 0 in case of success or negative value otherwise + */ +int zl3073x_write_reg(struct zl3073x_dev *zldev, unsigned int reg, + unsigned int len, const void *value) +{ + u8 buf[6]; + + lockdep_assert_held(&zldev->lock); + + switch (len) { + case 1: + buf[0] = *(u8 *)value; + break; + case 2: + put_unaligned_be16(*(u16 *)value, buf); + break; + case 4: + put_unaligned_be32(*(u32 *)value, buf); + break; + case 6: + put_unaligned_be48(*(u64 *)value, buf); + break; + default: + WARN(true, "Unsupported register size: %u\n", len); + break; + } + + return regmap_bulk_write(zldev->regmap, reg, buf, len); +} +EXPORT_SYMBOL_GPL(zl3073x_write_reg); + static const struct devlink_ops zl3073x_devlink_ops = { }; diff --git a/include/linux/mfd/zl3073x.h b/include/linux/mfd/zl3073x.h index 7b80c3059b5f3..0156f9044d79d 100644 --- a/include/linux/mfd/zl3073x.h +++ b/include/linux/mfd/zl3073x.h @@ -12,4 +12,36 @@ struct zl3073x_dev { struct mutex lock; }; +/** + * zl3073x_lock - Lock the device + * @zldev: device structure pointer + * + * Caller has to take this lock when it needs to access device registers. + */ +static inline void zl3073x_lock(struct zl3073x_dev *zldev) +{ + mutex_lock(&zldev->lock); +} + +/** + * zl3073x_unlock - Unlock the device + * @zldev: device structure pointer + * + * Caller unlocks the device when it does not need to access device + * registers anymore. + */ +static inline void zl3073x_unlock(struct zl3073x_dev *zldev) +{ + mutex_unlock(&zldev->lock); +} + +DEFINE_GUARD(zl3073x, struct zl3073x_dev *, zl3073x_lock(_T), + zl3073x_unlock(_T)); + +int zl3073x_read_reg(struct zl3073x_dev *zldev, unsigned int reg, + unsigned int len, void *value); + +int zl3073x_write_reg(struct zl3073x_dev *zldev, unsigned int reg, + unsigned int len, const void *value); + #endif /* __LINUX_MFD_ZL3073X_H */ -- 2.48.1
