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PCI: imx6: Add initial imx6sx support

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Add initial PCIe support for the imx6 SoC derivate imx6sx.  PCI MSI support
is untested as the necessary suspend/resume quirk is not included in this
patch.

This patch is heavily based on patches by Richard Zhu.

[bhelgaas: factor out refclk enable, fix adjacent typos in imx6q-pcie.txt]
Signed-off-by: Christoph Fritz <chf.fritz@googlemail.com>
Acked-by: Richard Zhu <Richard.Zhu@freescale.com>
Acked-by: Lucas Stach <l.stach@pengutronix.de>
This commit is contained in:
Christoph Fritz 2016-04-05 16:53:27 -05:00 committed by Bjorn Helgaas
parent 4d1821e729
commit e3c06cd063
2 changed files with 59 additions and 2 deletions
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8
Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
View file

@ -4,8 +4,8 @@ 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"
- reg: base addresse and length of the pcie controller
- compatible: "fsl,imx6q-pcie", "fsl,imx6sx-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:
@ -20,6 +20,10 @@ Optional properties:
- fsl,tx-swing-full: Gen2 TX SWING FULL value. Default: 127
- fsl,tx-swing-low: TX launch amplitude swing_low value. Default: 127
Additional required properties for imx6sx-pcie:
- clock names: Must include the following additional entries:
- "pcie_inbound_axi"
Example:
pcie@0x01000000 {

53
drivers/pci/host/pci-imx6.c
View file

@ -35,9 +35,11 @@ struct imx6_pcie {
int reset_gpio;
struct clk *pcie_bus;
struct clk *pcie_phy;
struct clk *pcie_inbound_axi;
struct clk *pcie;
struct pcie_port pp;
struct regmap *iomuxc_gpr;
bool is_imx6sx;
void __iomem *mem_base;
u32 tx_deemph_gen1;
u32 tx_deemph_gen2_3p5db;
@ -236,6 +238,17 @@ static int imx6_pcie_assert_core_reset(struct pcie_port *pp)
struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
u32 val, gpr1, gpr12;
if (imx6_pcie->is_imx6sx) {
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6SX_GPR12_PCIE_TEST_POWERDOWN,
IMX6SX_GPR12_PCIE_TEST_POWERDOWN);
/* Force PCIe PHY reset */
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
IMX6SX_GPR5_PCIE_BTNRST_RESET,
IMX6SX_GPR5_PCIE_BTNRST_RESET);
return 0;
}
/*
* If the bootloader already enabled the link we need some special
* handling to get the core back into a state where it is safe to
@ -271,6 +284,21 @@ static int imx6_pcie_assert_core_reset(struct pcie_port *pp)
static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
{
struct pcie_port *pp = &imx6_pcie->pp;
int ret;
if (imx6_pcie->is_imx6sx) {
ret = clk_prepare_enable(imx6_pcie->pcie_inbound_axi);
if (ret) {
dev_err(pp->dev, "unable to enable pcie_axi clock\n");
return ret;
}
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6SX_GPR12_PCIE_TEST_POWERDOWN, 0);
return ret;
}
/* power up core phy and enable ref clock */
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18);
@ -324,6 +352,11 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp)
msleep(100);
gpio_set_value_cansleep(imx6_pcie->reset_gpio, 1);
}
if (imx6_pcie->is_imx6sx)
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
IMX6SX_GPR5_PCIE_BTNRST_RESET, 0);
return 0;
err_ref_clk:
@ -341,6 +374,12 @@ static void imx6_pcie_init_phy(struct pcie_port *pp)
{
struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
if (imx6_pcie->is_imx6sx) {
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6SX_GPR12_PCIE_RX_EQ_MASK,
IMX6SX_GPR12_PCIE_RX_EQ_2);
}
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
@ -547,6 +586,9 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
pp = &imx6_pcie->pp;
pp->dev = &pdev->dev;
imx6_pcie->is_imx6sx = of_device_is_compatible(pp->dev->of_node,
"fsl,imx6sx-pcie");
/* Added for PCI abort handling */
hook_fault_code(16 + 6, imx6q_pcie_abort_handler, SIGBUS, 0,
"imprecise external abort");
@ -589,6 +631,16 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
return PTR_ERR(imx6_pcie->pcie);
}
if (imx6_pcie->is_imx6sx) {
imx6_pcie->pcie_inbound_axi = devm_clk_get(&pdev->dev,
"pcie_inbound_axi");
if (IS_ERR(imx6_pcie->pcie_inbound_axi)) {
dev_err(&pdev->dev,
"pcie_incbound_axi clock missing or invalid\n");
return PTR_ERR(imx6_pcie->pcie_inbound_axi);
}
}
/* Grab GPR config register range */
imx6_pcie->iomuxc_gpr =
syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
@ -636,6 +688,7 @@ static void imx6_pcie_shutdown(struct platform_device *pdev)
static const struct of_device_id imx6_pcie_of_match[] = {
{ .compatible = "fsl,imx6q-pcie", },
{ .compatible = "fsl,imx6sx-pcie", },
{},
};
MODULE_DEVICE_TABLE(of, imx6_pcie_of_match);