linux/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
Andrey Smirnov 4d31c6109a PCI: imx6: Implement reset sequence for i.MX6+
I.MX6+ has a dedicated bit for resetting PCIe core, which should be used
instead of a regular reset sequence since using the latter will hang the
SoC.

This commit is based on c34068d48273e24d392d9a49a38be807954420ed from
http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git

Tested-by: Gary Bisson <gary.bisson@boundarydevices.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
2016-05-02 14:33:17 -05:00

62 lines
2.7 KiB
Plaintext

* Freescale i.MX6 PCIe interface
This PCIe host controller is based on the Synopsis Designware PCIe IP
and thus inherits all the common properties defined in designware-pcie.txt.
Required properties:
- compatible: "fsl,imx6q-pcie", "fsl,imx6sx-pcie", "fsl,imx6qp-pcie"
- reg: base address and length of the PCIe controller
- interrupts: A list of interrupt outputs of the controller. Must contain an
entry for each entry in the interrupt-names property.
- interrupt-names: Must include the following entries:
- "msi": The interrupt that is asserted when an MSI is received
- clock-names: Must include the following additional entries:
- "pcie_phy"
Optional properties:
- fsl,tx-deemph-gen1: Gen1 De-emphasis value. Default: 0
- fsl,tx-deemph-gen2-3p5db: Gen2 (3.5db) De-emphasis value. Default: 0
- 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
- fsl,max-link-speed: Specify PCI gen for link capability. Must be '2' for
gen2, otherwise will default to gen1. Note that the IMX6 LVDS clock outputs
do not meet gen2 jitter requirements and thus for gen2 capability a gen2
compliant clock generator should be used and configured.
- reset-gpio: Should specify the GPIO for controlling the PCI bus device reset
signal. It's 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).
Additional required properties for imx6sx-pcie:
- clock names: Must include the following additional entries:
- "pcie_inbound_axi"
Example:
pcie@0x01000000 {
compatible = "fsl,imx6q-pcie", "snps,dw-pcie";
reg = <0x01ffc000 0x04000>,
<0x01f00000 0x80000>;
reg-names = "dbi", "config";
#address-cells = <3>;
#size-cells = <2>;
device_type = "pci";
ranges = <0x00000800 0 0x01f00000 0x01f00000 0 0x00080000
0x81000000 0 0 0x01f80000 0 0x00010000
0x82000000 0 0x01000000 0x01000000 0 0x00f00000>;
num-lanes = <1>;
interrupts = <GIC_SPI 120 IRQ_TYPE_LEVEL_HIGH>;
interrupt-names = "msi";
#interrupt-cells = <1>;
interrupt-map-mask = <0 0 0 0x7>;
interrupt-map = <0 0 0 1 &intc GIC_SPI 123 IRQ_TYPE_LEVEL_HIGH>,
<0 0 0 2 &intc GIC_SPI 122 IRQ_TYPE_LEVEL_HIGH>,
<0 0 0 3 &intc GIC_SPI 121 IRQ_TYPE_LEVEL_HIGH>,
<0 0 0 4 &intc GIC_SPI 120 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&clks 144>, <&clks 206>, <&clks 189>;
clock-names = "pcie", "pcie_bus", "pcie_phy";
};