Re: [PATCH v4 3/3] PCI: imx6: Add code to support i.MX7D

From: Rob Herring
Date: Wed Feb 15 2017 - 12:17:14 EST


On Tue, Feb 07, 2017 at 07:50:27AM -0800, Andrey Smirnov wrote:
> Add various bits of code needed to support i.MX7D variant of the IP.
>
> Cc: yurovsky@xxxxxxxxx
> Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: Lee Jones <lee.jones@xxxxxxxxxx>
> Cc: Fabio Estevam <fabio.estevam@xxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: devicetree@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
> ---
> .../devicetree/bindings/pci/fsl,imx6q-pcie.txt | 13 ++-
> drivers/pci/host/pci-imx6.c | 121 ++++++++++++++++-----
> include/linux/mfd/syscon/imx7-iomuxc-gpr.h | 4 +
> 3 files changed, 112 insertions(+), 26 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> index 83aeb1f..11db2ab 100644
> --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> @@ -4,7 +4,11 @@ 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"
> +- compatible:
> + - "fsl,imx6q-pcie"
> + - "fsl,imx6sx-pcie",
> + - "fsl,imx6qp-pcie"
> + - "fsl,imx7d-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.
> @@ -34,6 +38,13 @@ Additional required properties for imx6sx-pcie:
> - clock names: Must include the following additional entries:
> - "pcie_inbound_axi"
>
> +Additional required properties for imx7d-pcie:
> +- power-domains: Must be set to a phandle pointing to PCIE_PHY power domain

This domain is just the PHY? Seems like this needs a separate PHY
driver.

> +- resets: Must contain phandles to PCIE related reset lines exposed by SRC IP block
> +- reset-names: Must contain the following entires:
> + - "pciephy"

And for this too.

> + - "apps"
> +
> Example:
>
> pcie@0x01000000 {

[...]

> @@ -251,6 +261,10 @@ static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
> u32 val, gpr1, gpr12;
>
> switch (imx6_pcie->variant) {
> + case IMX7D:
> + reset_control_assert(imx6_pcie->pciephy_reset);
> + reset_control_assert(imx6_pcie->apps_reset);
> + break;
> case IMX6SX:
> regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> IMX6SX_GPR12_PCIE_TEST_POWERDOWN,

So the difference with i.MX7D is not really that it has a reset or not,
but some platforms use a reset driver and some do not. The latter should
be fixed.

Rob