We need that property in order to make the Toradex Apalis SoMs working
without breaking old DTBs. On Apalis SoMs the GPIO1_IO28 used to PCIe
reset is not connected directly to PERST# PCIe signal, but it's ORed
with RESETBMCU coming off the PMIC, and thus is inverted, active-high.
Signed-off-by: Petr Štetiar <ynezz@xxxxxxx>
---
Changes since v1:
* Added documentation of reset-gpio and reset-gpio-active-high DT properties
* Removed unnecessary double negation of GPIO value
Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt | 5 +++++
drivers/pci/host/pci-imx6.c | 14 +++++++++++---
2 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
index 3be80c6..23ecb47 100644
--- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
@@ -19,6 +19,11 @@ Optional properties:
- fsl,tx-deemph-gen2-6db: Gen2 (6db) De-emphasis value. Default: 20
- fsl,tx-swing-full: Gen2 TX SWING FULL value. Default: 127
- fsl,tx-swing-low: TX launch amplitude swing_low value. Default: 127
+- reset-gpio: Should specify the GPIO for PHY reset. Its not polarity aware
+ and defaults to active-low reset sequence (L=reset state, H=operation state).
+- reset-gpio-active-high: If present then the reset sequence using the GPIO
+ specified in the "reset-gpio" property is reversed (H=reset state,
+ L=operation state).
Example:
diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
index 2f817fa..17f4cc3 100644
--- a/drivers/pci/host/pci-imx6.c
+++ b/drivers/pci/host/pci-imx6.c
@@ -33,6 +33,7 @@
struct imx6_pcie {
int reset_gpio;
+ bool gpio_active_high;
struct clk *pcie_bus;
struct clk *pcie_phy;
struct clk *pcie;
@@ -310,9 +311,11 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp)
/* Some boards don't have PCIe reset GPIO. */
if (gpio_is_valid(imx6_pcie->reset_gpio)) {
- gpio_set_value_cansleep(imx6_pcie->reset_gpio, 0);
+ gpio_set_value_cansleep(imx6_pcie->reset_gpio,
+ imx6_pcie->gpio_active_high);
msleep(100);
- gpio_set_value_cansleep(imx6_pcie->reset_gpio, 1);
+ gpio_set_value_cansleep(imx6_pcie->reset_gpio,
+ !imx6_pcie->gpio_active_high);
}
return 0;
@@ -546,9 +549,14 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
/* Fetch GPIOs */
imx6_pcie->reset_gpio = of_get_named_gpio(np, "reset-gpio", 0);
+ imx6_pcie->gpio_active_high = of_property_read_bool(np,
+ "reset-gpio-active-high");
if (gpio_is_valid(imx6_pcie->reset_gpio)) {
ret = devm_gpio_request_one(&pdev->dev, imx6_pcie->reset_gpio,
- GPIOF_OUT_INIT_LOW, "PCIe reset");
+ imx6_pcie->gpio_active_high ?
+ GPIOF_OUT_INIT_HIGH :
+ GPIOF_OUT_INIT_LOW,
+ "PCIe reset");
if (ret) {
dev_err(&pdev->dev, "unable to get reset gpio\n");
return ret;
--
1.9.1
--
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