[PATCH v9 09/10] serial: sc16is7xx: add post reset delay
From: Hugo Villeneuve <hidden>
Date: 2023-07-25 14:24:58
Also in:
linux-gpio, linux-serial, lkml
Subsystem:
the rest, tty layer and serial drivers · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
From: Hugo Villeneuve <hvilleneuve@dimonoff.com> Make sure we wait at least 3us before initiating communication with the device after reset. Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Reviewed-by: Lech Perczak <redacted> Tested-by: Lech Perczak <redacted> --- drivers/tty/serial/sc16is7xx.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 49213be60baf..718e982e1efe 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c@@ -1526,6 +1526,12 @@ static int sc16is7xx_probe(struct device *dev, regmap_write(s->regmap, SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT, SC16IS7XX_IOCONTROL_SRESET_BIT); + /* + * After reset, the host must wait at least 3us before initializing a + * communication with the device. + */ + usleep_range(5, 10); + for (i = 0; i < devtype->nr_uart; ++i) { s->p[i].line = i; /* Initialize port data */
--
2.30.2