diff options
| author | Linus Walleij <linus.walleij@linaro.org> | 2025-08-13 23:43:04 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-08-18 17:26:09 -0700 |
| commit | ccf29cb84972f97c98ac31f7d6fb1680dc5d3816 (patch) | |
| tree | 65e35acbe75158d0dd930c9a78864ed6c078f977 | |
| parent | 60cbe71fdba16d39de24bd71e1638810da5ae7ee (diff) | |
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: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20250813-ks8995-to-dsa-v1-2-75c359ede3a5@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/dsa/ks8995.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/net/dsa/ks8995.c b/drivers/net/dsa/ks8995.c index d135b061d810..bdee8c62315f 100644 --- a/drivers/net/dsa/ks8995.c +++ b/drivers/net/dsa/ks8995.c @@ -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 */ - gpiod_set_value_cansleep(ks->reset_gpio, 0); + 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); |