[PATCH v5 4/4] PCI: imx6: Add support for i.MX8MQ

From: Andrey Smirnov
Date: Sat Jan 12 2019 - 16:56:33 EST


Add code needed to support i.MX8MQ variant.

Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Fabio Estevam <fabio.estevam@xxxxxxx>
Cc: Chris Healy <cphealy@xxxxxxxxx>
Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
Cc: Leonard Crestez <leonard.crestez@xxxxxxx>
Cc: "A.s. Dong" <aisheng.dong@xxxxxxx>
Cc: Richard Zhu <hongxing.zhu@xxxxxxx>
Cc: linux-imx@xxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-pci@xxxxxxxxxxxxxxx
Reviewed-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
---
.../bindings/pci/fsl,imx6q-pcie.txt | 3 +-
drivers/pci/controller/dwc/Kconfig | 4 +-
drivers/pci/controller/dwc/pci-imx6.c | 77 ++++++++++++++++++-
3 files changed, 79 insertions(+), 5 deletions(-)

diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
index d514c1f2365f..920ca93870a8 100644
--- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
@@ -9,6 +9,7 @@ Required properties:
- "fsl,imx6sx-pcie",
- "fsl,imx6qp-pcie"
- "fsl,imx7d-pcie"
+ - "fsl,imx8mq-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.
@@ -45,7 +46,7 @@ Additional required properties for imx6sx-pcie:
PCIE_PHY power domains
- power-domain-names: Must be "pcie", "pcie_phy"

-Additional required properties for imx7d-pcie:
+Additional required properties for imx7d-pcie and imx8mq-pcie:
- power-domains: Must be set to a phandle pointing to PCIE_PHY power domain
- resets: Must contain phandles to PCIe-related reset lines exposed by SRC
IP block
diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 6aafec3fad00..adf7f2061890 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -89,8 +89,8 @@ config PCI_EXYNOS
select PCIE_DW_HOST

config PCI_IMX6
- bool "Freescale i.MX6/7 PCIe controller"
- depends on SOC_IMX6Q || SOC_IMX7D || (ARM && COMPILE_TEST)
+ bool "Freescale i.MX6/7/8 PCIe controller"
+ depends on SOC_IMX6Q || SOC_IMX7D || (ARM64 && ARCH_MXC) || COMPILE_TEST
depends on PCI_MSI_IRQ_DOMAIN
select PCIE_DW_HOST

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 75ee0cd7af3b..dd9d8732f6ba 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -8,6 +8,7 @@
* Author: Sean Cross <xobs@xxxxxxxxxx>
*/

+#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/gpio.h>
@@ -32,6 +33,12 @@

#include "pcie-designware.h"

+#define IMX8MQ_GPR_PCIE_REF_USE_PAD BIT(9)
+#define IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE_EN BIT(10)
+#define IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE BIT(11)
+#define IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE GENMASK(11, 8)
+#define IMX8MQ_PCIE2_BASE_ADDR 0x33c00000
+
#define to_imx6_pcie(x) dev_get_drvdata((x)->dev)

enum imx6_pcie_variants {
@@ -39,6 +46,7 @@ enum imx6_pcie_variants {
IMX6SX,
IMX6QP,
IMX7D,
+ IMX8MQ,
};

#define IMX6_PCIE_FLAG_IMX6_PHY BIT(0)
@@ -58,6 +66,7 @@ struct imx6_pcie {
struct clk *pcie_inbound_axi;
struct clk *pcie;
struct regmap *iomuxc_gpr;
+ u32 controller_id;
struct reset_control *pciephy_reset;
struct reset_control *apps_reset;
struct reset_control *turnoff_reset;
@@ -276,6 +285,7 @@ static void imx6_pcie_reset_phy(struct imx6_pcie *imx6_pcie)
pcie_phy_write(imx6_pcie, PHY_RX_OVRD_IN_LO, tmp);
}

+#ifdef CONFIG_ARM
/* Added for PCI abort handling */
static int imx6q_pcie_abort_handler(unsigned long addr,
unsigned int fsr, struct pt_regs *regs)
@@ -309,6 +319,7 @@ static int imx6q_pcie_abort_handler(unsigned long addr,

return 1;
}
+#endif

static int imx6_pcie_attach_pd(struct device *dev)
{
@@ -353,6 +364,7 @@ static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)

switch (imx6_pcie->drvdata->variant) {
case IMX7D:
+ case IMX8MQ:
reset_control_assert(imx6_pcie->pciephy_reset);
reset_control_assert(imx6_pcie->apps_reset);
break;
@@ -387,10 +399,17 @@ 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);
+ return imx6_pcie->controller_id == 1 ? IOMUXC_GPR16 : IOMUXC_GPR14;
+}
+
static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
{
struct dw_pcie *pci = imx6_pcie->pci;
struct device *dev = pci->dev;
+ unsigned int offset;
int ret = 0;

switch (imx6_pcie->drvdata->variant) {
@@ -421,6 +440,19 @@ static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
break;
case IMX7D:
break;
+ case IMX8MQ:
+ offset = imx6_pcie_grp_offset(imx6_pcie);
+ /*
+ * Set the over ride low and enabled
+ * make sure that REF_CLK is turned on.
+ */
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, offset,
+ IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE,
+ 0);
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, offset,
+ IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE_EN,
+ IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE_EN);
+ break;
}

return ret;
@@ -497,6 +529,9 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
}

switch (imx6_pcie->drvdata->variant) {
+ case IMX8MQ:
+ reset_control_deassert(imx6_pcie->pciephy_reset);
+ break;
case IMX7D:
reset_control_deassert(imx6_pcie->pciephy_reset);
imx7d_pcie_wait_for_phy_pll_lock(imx6_pcie);
@@ -532,9 +567,37 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
}
}

+static void imx6_pcie_configure_type(struct imx6_pcie *imx6_pcie)
+{
+ unsigned int mask, val;
+
+ if (imx6_pcie->drvdata->variant == IMX8MQ &&
+ imx6_pcie->controller_id == 1) {
+ mask = IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE;
+ val = FIELD_PREP(IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE,
+ PCI_EXP_TYPE_ROOT_PORT);
+ } else {
+ mask = IMX6Q_GPR12_DEVICE_TYPE;
+ val = FIELD_PREP(IMX6Q_GPR12_DEVICE_TYPE,
+ PCI_EXP_TYPE_ROOT_PORT);
+ }
+
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, mask, val);
+}
+
static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
{
switch (imx6_pcie->drvdata->variant) {
+ case IMX8MQ:
+ /*
+ * TODO: Currently this code assumes external
+ * oscillator is being used
+ */
+ regmap_update_bits(imx6_pcie->iomuxc_gpr,
+ imx6_pcie_grp_offset(imx6_pcie),
+ IMX8MQ_GPR_PCIE_REF_USE_PAD,
+ IMX8MQ_GPR_PCIE_REF_USE_PAD);
+ break;
case IMX7D:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX7D_GPR12_PCIE_PHY_REFCLK_SEL, 0);
@@ -570,8 +633,7 @@ static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
break;
}

- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
- IMX6Q_GPR12_DEVICE_TYPE, PCI_EXP_TYPE_ROOT_PORT << 12);
+ imx6_pcie_configure_type(imx6_pcie);
}

static int imx6_setup_phy_mpll(struct imx6_pcie *imx6_pcie)
@@ -668,6 +730,7 @@ static void imx6_pcie_ltssm_enable(struct device *dev)
IMX6Q_GPR12_PCIE_CTL_2);
break;
case IMX7D:
+ case IMX8MQ:
reset_control_deassert(imx6_pcie->apps_reset);
break;
}
@@ -1008,6 +1071,10 @@ static int imx6_pcie_probe(struct platform_device *pdev)
}
break;
case IMX7D:
+ case IMX8MQ:
+ if (dbi_base->start == IMX8MQ_PCIE2_BASE_ADDR)
+ imx6_pcie->controller_id = 1;
+
imx6_pcie->pciephy_reset = devm_reset_control_get_exclusive(dev,
"pciephy");
if (IS_ERR(imx6_pcie->pciephy_reset)) {
@@ -1115,6 +1182,9 @@ static const struct imx6_pcie_drvdata drvdata[] = {
[IMX7D] = {
.variant = IMX7D,
},
+ [IMX8MQ] = {
+ .variant = IMX8MQ,
+ },
};

static const struct of_device_id imx6_pcie_of_match[] = {
@@ -1122,6 +1192,7 @@ 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], } ,
{},
};

@@ -1138,6 +1209,7 @@ static struct platform_driver imx6_pcie_driver = {

static int __init imx6_pcie_init(void)
{
+#ifdef CONFIG_ARM
/*
* Since probe() can be deferred we need to make sure that
* hook_fault_code is not called after __init memory is freed
@@ -1147,6 +1219,7 @@ static int __init imx6_pcie_init(void)
*/
hook_fault_code(8, imx6q_pcie_abort_handler, SIGBUS, 0,
"external abort on non-linefetch");
+#endif

return platform_driver_register(&imx6_pcie_driver);
}
--
2.20.1