[PATCH v6 8/8] PCI: imx: Add the imx8mm pcie support

Richard Zhu
2021-11-18T02:22:02Z

i.MX8MM PCIe works mostly like the i.MX8MQ one, but has a different PHY
and allows to output the internal PHY reference clock via the refclk pad.
Add the i.MX8MM PCIe support based on the standalone PHY driver.

Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Tim Harvey <tharvey@gateworks.com>
Tested-by: Tim Harvey <tharvey@gateworks.com>
---
drivers/pci/controller/dwc/pci-imx6.c | 73 ++++++++++++++++++++++++---
1 file changed, 66 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 26f49f797b0f..d8c587b4d54f 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -29,6 +29,7 @@
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/reset.h>
+#include <linux/phy/phy.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>

@@ -49,6 +50,7 @@ enum imx6_pcie_variants {
IMX6QP,
IMX7D,
IMX8MQ,
+ IMX8MM,
};

#define IMX6_PCIE_FLAG_IMX6_PHY BIT(0)
@@ -88,6 +90,7 @@ struct imx6_pcie {
struct device *pd_pcie;
/* power domain for pcie phy */
struct device *pd_pcie_phy;
+ struct phy *phy;
const struct imx6_pcie_drvdata *drvdata;
};

@@ -372,6 +375,8 @@ static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
case IMX7D:
case IMX8MQ:
reset_control_assert(imx6_pcie->pciephy_reset);
+ fallthrough;
+ case IMX8MM:
reset_control_assert(imx6_pcie->apps_reset);
break;
case IMX6SX:
@@ -407,7 +412,8 @@ static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)

static unsigned int imx6_pcie_grp_offset(const struct imx6_pcie *imx6_pcie)
{
- WARN_ON(imx6_pcie->drvdata->variant != IMX8MQ);
+ WARN_ON(imx6_pcie->drvdata->variant != IMX8MQ &&
+ imx6_pcie->drvdata->variant != IMX8MM);
return imx6_pcie->controller_id == 1 ? IOMUXC_GPR16 : IOMUXC_GPR14;
}

@@ -446,6 +452,13 @@ static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
break;
case IMX7D:
break;
+ case IMX8MM:
+ ret = clk_prepare_enable(imx6_pcie->pcie_aux);
+ if (ret) {
+ dev_err(dev, "unable to enable pcie_aux clock\n");
+ break;
+ }
+ break;
case IMX8MQ:
ret = clk_prepare_enable(imx6_pcie->pcie_aux);
if (ret) {
@@ -522,6 +535,14 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
goto err_ref_clk;
}

+ switch (imx6_pcie->drvdata->variant) {
+ case IMX8MM:
+ if (phy_power_on(imx6_pcie->phy))
+ dev_err(dev, "unable to power on PHY\n");
+ break;
+ default:
+ break;
+ }
/* allow the clocks to stabilize */
usleep_range(200, 500);

@@ -538,6 +559,10 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
case IMX8MQ:
reset_control_deassert(imx6_pcie->pciephy_reset);
break;
+ case IMX8MM:
+ if (phy_init(imx6_pcie->phy) != 0)
+ dev_err(dev, "Waiting for PHY ready timeout!\n");
+ break;
case IMX7D:
reset_control_deassert(imx6_pcie->pciephy_reset);

@@ -614,6 +639,8 @@ static void imx6_pcie_configure_type(struct imx6_pcie *imx6_pcie)
static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
{
switch (imx6_pcie->drvdata->variant) {
+ case IMX8MM:
+ break;
case IMX8MQ:
/*
* TODO: Currently this code assumes external
@@ -753,6 +780,7 @@ static void imx6_pcie_ltssm_enable(struct device *dev)
break;
case IMX7D:
case IMX8MQ:
+ case IMX8MM:
reset_control_deassert(imx6_pcie->apps_reset);
break;
}
@@ -871,6 +899,7 @@ static void imx6_pcie_ltssm_disable(struct device *dev)
IMX6Q_GPR12_PCIE_CTL_2, 0);
break;
case IMX7D:
+ case IMX8MM:
reset_control_assert(imx6_pcie->apps_reset);
break;
default:
@@ -930,6 +959,7 @@ static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
IMX7D_GPR12_PCIE_PHY_REFCLK_SEL);
break;
case IMX8MQ:
+ case IMX8MM:
clk_disable_unprepare(imx6_pcie->pcie_aux);
break;
default:
@@ -1043,11 +1073,6 @@ static int imx6_pcie_probe(struct platform_device *pdev)
}

/* Fetch clocks */
- imx6_pcie->pcie_phy = devm_clk_get(dev, "pcie_phy");
- if (IS_ERR(imx6_pcie->pcie_phy))
- return dev_err_probe(dev, PTR_ERR(imx6_pcie->pcie_phy),
- "pcie_phy clock source missing or invalid\n");
-
imx6_pcie->pcie_bus = devm_clk_get(dev, "pcie_bus");
if (IS_ERR(imx6_pcie->pcie_bus))
return dev_err_probe(dev, PTR_ERR(imx6_pcie->pcie_bus),
@@ -1089,10 +1114,39 @@ static int imx6_pcie_probe(struct platform_device *pdev)
dev_err(dev, "Failed to get PCIE APPS reset control\n");
return PTR_ERR(imx6_pcie->apps_reset);
}
+ break;
+ case IMX8MM:
+ imx6_pcie->pcie_aux = devm_clk_get(dev, "pcie_aux");
+ if (IS_ERR(imx6_pcie->pcie_aux))
+ return dev_err_probe(dev, PTR_ERR(imx6_pcie->pcie_aux),
+ "pcie_aux clock source missing or invalid\n");
+ imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev,
+ "apps");
+ if (IS_ERR(imx6_pcie->apps_reset)) {
+ dev_err(dev, "Failed to get PCIE APPS reset control\n");
+ return PTR_ERR(imx6_pcie->apps_reset);
+ }
+
+ imx6_pcie->phy = devm_phy_get(dev, "pcie-phy");
+ if (IS_ERR(imx6_pcie->phy)) {
+ if (PTR_ERR(imx6_pcie->phy) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+ dev_err(dev, "Failed to get PCIE PHY\n");
+ return PTR_ERR(imx6_pcie->phy);
+ }
+
break;
default:
break;
}
+ /* Don't fetch the pcie_phy clock, if it has abstract PHY driver */
+ if (imx6_pcie->phy == NULL) {
+ imx6_pcie->pcie_phy = devm_clk_get(dev, "pcie_phy");
+ if (IS_ERR(imx6_pcie->pcie_phy))
+ return dev_err_probe(dev, PTR_ERR(imx6_pcie->pcie_phy),
+ "pcie_phy clock source missing or invalid\n");
+ }
+

/* Grab turnoff reset */
imx6_pcie->turnoff_reset = devm_reset_control_get_optional_exclusive(dev, "turnoff");
@@ -1202,6 +1256,10 @@ static const struct imx6_pcie_drvdata drvdata[] = {
[IMX8MQ] = {
.variant = IMX8MQ,
},
+ [IMX8MM] = {
+ .variant = IMX8MM,
+ .flags = IMX6_PCIE_FLAG_SUPPORTS_SUSPEND,
+ },
};

static const struct of_device_id imx6_pcie_of_match[] = {
@@ -1209,7 +1267,8 @@ static const struct of_device_id imx6_pcie_of_match[] = {
{ .compatible = "fsl,imx6sx-pcie", .data = &drvdata[IMX6SX], },
{ .compatible = "fsl,imx6qp-pcie", .data = &drvdata[IMX6QP], },
{ .compatible = "fsl,imx7d-pcie", .data = &drvdata[IMX7D], },
- { .compatible = "fsl,imx8mq-pcie", .data = &drvdata[IMX8MQ], } ,
+ { .compatible = "fsl,imx8mq-pcie", .data = &drvdata[IMX8MQ], },
+ { .compatible = "fsl,imx8mm-pcie", .data = &drvdata[IMX8MM], },
{},
};

--
2.25.1