Commit ccf29cb8 authored by Linus Walleij's avatar Linus Walleij Committed by Jakub Kicinski
Browse files

net: dsa: ks8995: Add proper RESET delay 



According to the datasheet we need to wait 100us before accessing
any registers in the KS8995 after a reset de-assertion.

Add this delay, if and only if we obtained a GPIO descriptor,
otherwise it is just a pointless delay.

Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20250813-ks8995-to-dsa-v1-2-75c359ede3a5@linaro.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 60cbe71f

drivers/net/dsa/ks8995.c

+9 −3
Original line number Diff line number Diff line
@@ -438,9 +438,15 @@ static int ks8995_probe(struct spi_device *spi) 
	if (err)

		return err;



	/* de-assert switch reset */

	/* FIXME: this likely requires a delay */

	if (ks->reset_gpio) {

		/*

		 * If a reset line was obtained, wait for 100us after

		 * de-asserting RESET before accessing any registers, see

		 * the KS8995MA datasheet, page 44.

		 */

		gpiod_set_value_cansleep(ks->reset_gpio, 0);

		udelay(100);

	}



	spi_set_drvdata(spi, ks);