rtc: add dm_rtc_read helper and ->read method

Some users may want to read multiple consecutive 8-bit
registers. Instead of each caller having to implement the loop,
provide a dm_rtc_read() helper. Also, allow a driver to provide a
->read method, which can be more efficient than reading one register
at a time.

Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
This commit is contained in:
Rasmus Villemoes 2020-07-06 22:01:10 +02:00 committed by Heiko Schocher
parent 35d3982e23
commit d8be08805b
2 changed files with 42 additions and 0 deletions

View File

@ -40,6 +40,25 @@ int dm_rtc_reset(struct udevice *dev)
return ops->reset(dev);
}
int dm_rtc_read(struct udevice *dev, unsigned int reg, u8 *buf, unsigned int len)
{
struct rtc_ops *ops = rtc_get_ops(dev);
assert(ops);
if (ops->read)
return ops->read(dev, reg, buf, len);
if (!ops->read8)
return -ENOSYS;
while (len--) {
int ret = ops->read8(dev, reg++);
if (ret < 0)
return ret;
*buf++ = ret;
}
return 0;
}
int rtc_read8(struct udevice *dev, unsigned int reg)
{
struct rtc_ops *ops = rtc_get_ops(dev);

View File

@ -55,6 +55,18 @@ struct rtc_ops {
*/
int (*reset)(struct udevice *dev);
/**
* read() - Read multiple 8-bit registers
*
* @dev: Device to read from
* @reg: First register to read
* @buf: Output buffer
* @len: Number of registers to read
* @return 0 if OK, -ve on error
*/
int (*read)(struct udevice *dev, unsigned int reg,
u8 *buf, unsigned int len);
/**
* read8() - Read an 8-bit register
*
@ -109,6 +121,17 @@ int dm_rtc_set(struct udevice *dev, struct rtc_time *time);
*/
int dm_rtc_reset(struct udevice *dev);
/**
* dm_rtc_read() - Read multiple 8-bit registers
*
* @dev: Device to read from
* @reg: First register to read
* @buf: Output buffer
* @len: Number of registers to read
* @return 0 if OK, -ve on error
*/
int dm_rtc_read(struct udevice *dev, unsigned int reg, u8 *buf, unsigned int len);
/**
* rtc_read8() - Read an 8-bit register
*