diff options
| -rw-r--r-- | drivers/serial/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/serial/serial-uclass.c | 26 | ||||
| -rw-r--r-- | include/serial.h | 18 |
3 files changed, 55 insertions, 2 deletions
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index a07fab225f..76171e7146 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -133,6 +133,19 @@ config SERIAL_RX_BUFFER_SIZE help The size of the RX buffer (needs to be power of 2) +config SERIAL_PUTS + bool "Enable printing strings all at once" + depends on DM_SERIAL + help + Some serial drivers are much more efficient when printing multiple + characters at once rather than printing characters individually. This + can be because they can load a fifo, or because individual print + calls have a constant overhead. With this option set, the serial + subsystem will try to provide serial drivers with as many characters + at once as possible, instead of printing characters one by one. Most + serial drivers do not need this config to print efficiently. If + unsure, say N. + config SERIAL_SEARCH_ALL bool "Search for serial devices after default one failed" depends on DM_SERIAL diff --git a/drivers/serial/serial-uclass.c b/drivers/serial/serial-uclass.c index f30f352bd7..10d6b800e2 100644 --- a/drivers/serial/serial-uclass.c +++ b/drivers/serial/serial-uclass.c @@ -200,8 +200,30 @@ static void _serial_putc(struct udevice *dev, char ch) static void _serial_puts(struct udevice *dev, const char *str) { - while (*str) - _serial_putc(dev, *str++); + struct dm_serial_ops *ops = serial_get_ops(dev); + + if (!CONFIG_IS_ENABLED(SERIAL_PUTS) || !ops->puts) { + while (*str) + _serial_putc(dev, *str++); + return; + } + + do { + const char *newline = strchrnul(str, '\n'); + size_t len = newline - str + !!*newline; + + do { + ssize_t written = ops->puts(dev, str, len); + + if (written < 0) + return; + str += written; + len -= written; + } while (len); + + if (*newline) + _serial_putc(dev, '\r'); + } while (*str); } static int __serial_getc(struct udevice *dev) diff --git a/include/serial.h b/include/serial.h index 2681d26c82..8c2e7adbc3 100644 --- a/include/serial.h +++ b/include/serial.h @@ -196,6 +196,24 @@ struct dm_serial_ops { */ int (*putc)(struct udevice *dev, const char ch); /** + * puts() - Write a string + * + * This writes a string. This function should be implemented only if + * writing multiple characters at once is more performant than just + * calling putc() in a loop. + * + * If the whole string cannot be written at once, then this function + * should return the number of characters written. Returning a negative + * error code implies that no characters were written. If this function + * returns 0, then it will be called again with the same arguments. + * + * @dev: Device pointer + * @s: The string to write + * @len: The length of the string to write. + * @return The number of characters written on success, or -ve on error + */ + ssize_t (*puts)(struct udevice *dev, const char *s, size_t len); + /** * pending() - Check if input/output characters are waiting * * This can be used to return an indication of the number of waiting |