mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-30 02:29:01 +00:00
63 lines
2.3 KiB
Diff
63 lines
2.3 KiB
Diff
|
From f038380835033e376d89c72516f087254792bbad Mon Sep 17 00:00:00 2001
|
||
|
|
From: Martin Schiller <ms@dev.tdt.de>
|
||
|
|
Date: Mon, 6 May 2024 09:41:42 +0200
|
||
|
|
Subject: [PATCH] MIPS: pci: lantiq: restore reset gpio polarity
|
||
|
|
|
||
|
|
Commit 90c2d2eb7ab5 ("MIPS: pci: lantiq: switch to using gpiod API") not
|
||
|
|
only switched to the gpiod API, but also inverted / changed the polarity
|
||
|
|
of the GPIO.
|
||
|
|
|
||
|
|
According to the PCI specification, the RST# pin is an active-low
|
||
|
|
signal. However, most of the device trees that have been widely used for
|
||
|
|
a long time (mainly in the openWrt project) define this GPIO as
|
||
|
|
active-high and the old driver code inverted the signal internally.
|
||
|
|
|
||
|
|
Apparently there are actually boards where the reset gpio must be
|
||
|
|
operated inverted. For this reason, we cannot use the GPIOD_OUT_LOW/HIGH
|
||
|
|
flag for initialization. Instead, we must explicitly set the gpio to
|
||
|
|
value 1 in order to take into account any "GPIO_ACTIVE_LOW" flag that
|
||
|
|
may have been set.
|
||
|
|
|
||
|
|
In order to remain compatible with all these existing device trees, we
|
||
|
|
should therefore keep the logic as it was before the commit.
|
||
|
|
|
||
|
|
Fixes: 90c2d2eb7ab5 ("MIPS: pci: lantiq: switch to using gpiod API")
|
||
|
|
Cc: stable@vger.kernel.org
|
||
|
|
Signed-off-by: Martin Schiller <ms@dev.tdt.de>
|
||
|
|
---
|
||
|
|
arch/mips/pci/pci-lantiq.c | 8 ++++----
|
||
|
|
1 file changed, 4 insertions(+), 4 deletions(-)
|
||
|
|
|
||
|
|
--- a/arch/mips/pci/pci-lantiq.c
|
||
|
|
+++ b/arch/mips/pci/pci-lantiq.c
|
||
|
|
@@ -124,14 +124,14 @@ static int ltq_pci_startup(struct platfo
|
||
|
|
clk_disable(clk_external);
|
||
|
|
|
||
|
|
/* setup reset gpio used by pci */
|
||
|
|
- reset_gpio = devm_gpiod_get_optional(&pdev->dev, "reset",
|
||
|
|
- GPIOD_OUT_LOW);
|
||
|
|
+ reset_gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_ASIS);
|
||
|
|
error = PTR_ERR_OR_ZERO(reset_gpio);
|
||
|
|
if (error) {
|
||
|
|
dev_err(&pdev->dev, "failed to request gpio: %d\n", error);
|
||
|
|
return error;
|
||
|
|
}
|
||
|
|
gpiod_set_consumer_name(reset_gpio, "pci_reset");
|
||
|
|
+ gpiod_direction_output(reset_gpio, 1);
|
||
|
|
|
||
|
|
/* enable auto-switching between PCI and EBU */
|
||
|
|
ltq_pci_w32(0xa, PCI_CR_CLK_CTRL);
|
||
|
|
@@ -194,10 +194,10 @@ static int ltq_pci_startup(struct platfo
|
||
|
|
|
||
|
|
/* toggle reset pin */
|
||
|
|
if (reset_gpio) {
|
||
|
|
- gpiod_set_value_cansleep(reset_gpio, 1);
|
||
|
|
+ gpiod_set_value_cansleep(reset_gpio, 0);
|
||
|
|
wmb();
|
||
|
|
mdelay(1);
|
||
|
|
- gpiod_set_value_cansleep(reset_gpio, 0);
|
||
|
|
+ gpiod_set_value_cansleep(reset_gpio, 1);
|
||
|
|
}
|
||
|
|
return 0;
|
||
|
|
}
|