[PATCH v2 3/3] PCI: imx: Add support for i.MX8MQ

From: Andrey Smirnov
Date: Thu Dec 06 2018 - 02:36:04 EST


Add code needed to support i.MX8MQ variant.

Cc: bhelgaas@xxxxxxxxxx
Cc: Fabio Estevam <fabio.estevam@xxxxxxx>
Cc: cphealy@xxxxxxxxx
Cc: 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
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Cc: devicetree@xxxxxxxxxxxxxxx
Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
---
.../bindings/pci/fsl,imx6q-pcie.txt | 6 +-
drivers/pci/controller/dwc/Kconfig | 2 +-
drivers/pci/controller/dwc/pci-imx6.c | 85 +++++++++++++++++--
3 files changed, 86 insertions(+), 7 deletions(-)

diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
index f37494d5a7be..40b46d11e7e7 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.
@@ -43,7 +44,7 @@ Additional required properties for imx6sx-pcie:
- "pcie_inbound_axi"
- power-domains: Must be set to a phandle pointing to the PCIE_PHY power domain

-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
@@ -52,6 +53,9 @@ Additional required properties for imx7d-pcie:
- "apps"
- "turnoff"

+Additional required properties for imx8mq-pcie:
+- fsl,controller-id: Logical ID of a given PCIE controller. PCIE1 is 0, PCIE2 is 1;
+
Example:

pcie@01000000 {
diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 91b0194240a5..2b139acccf32 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -90,7 +90,7 @@ config PCI_EXYNOS

config PCI_IMX6
bool "Freescale i.MX6 PCIe controller"
- depends on SOC_IMX6Q || (ARM && COMPILE_TEST)
+ depends on SOC_IMX8MQ || SOC_IMX6Q || (ARM && 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 3c3002861d25..326f71698ac2 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>
@@ -30,6 +31,11 @@

#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 to_imx6_pcie(x) dev_get_drvdata((x)->dev)

enum imx6_pcie_variants {
@@ -37,6 +43,7 @@ enum imx6_pcie_variants {
IMX6SX,
IMX6QP,
IMX7D,
+ IMX8MQ,
};

struct imx6_pcie {
@@ -48,6 +55,7 @@ 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;
@@ -245,7 +253,8 @@ static void imx6_pcie_reset_phy(struct imx6_pcie *imx6_pcie)
{
u32 tmp;

- if (imx6_pcie->variant == IMX7D)
+ if (imx6_pcie->variant == IMX7D ||
+ imx6_pcie->variant == IMX8MQ)
return;

pcie_phy_read(imx6_pcie, PHY_RX_OVRD_IN_LO, &tmp);
@@ -261,6 +270,7 @@ 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)
@@ -294,6 +304,7 @@ static int imx6q_pcie_abort_handler(unsigned long addr,

return 1;
}
+#endif

static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
{
@@ -301,6 +312,7 @@ static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)

switch (imx6_pcie->variant) {
case IMX7D:
+ case IMX8MQ: /* FALLTHROUGH */
reset_control_assert(imx6_pcie->pciephy_reset);
reset_control_assert(imx6_pcie->apps_reset);
break;
@@ -339,6 +351,7 @@ 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->variant) {
@@ -369,6 +382,29 @@ static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
break;
case IMX7D:
break;
+ case IMX8MQ:
+ switch (imx6_pcie->controller_id) {
+ case 0:
+ offset = IOMUXC_GPR14;
+ break;
+ case 1:
+ offset = IOMUXC_GPR16;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /*
+ * 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;
@@ -445,6 +481,9 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
}

switch (imx6_pcie->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);
@@ -482,7 +521,34 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)

static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
{
+ unsigned int mask, val, offset;
+
+ mask = IMX6Q_GPR12_DEVICE_TYPE;
+ val = FIELD_PREP(IMX6Q_GPR12_DEVICE_TYPE, PCI_EXP_TYPE_ROOT_PORT);
+
switch (imx6_pcie->variant) {
+ case IMX8MQ:
+ switch (imx6_pcie->controller_id) {
+ case 0:
+ offset = IOMUXC_GPR14;
+ break;
+ case 1:
+ offset = IOMUXC_GPR16;
+ mask = IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE;
+ val = FIELD_PREP(IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE,
+ PCI_EXP_TYPE_ROOT_PORT);
+ break;
+ default:
+ return;
+ }
+ /*
+ * TODO: Currently this code assumes external
+ * oscillator is being used
+ */
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, offset,
+ 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);
@@ -518,8 +584,7 @@ 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);
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, mask, val);
}

static int imx6_setup_phy_mpll(struct imx6_pcie *imx6_pcie)
@@ -528,7 +593,8 @@ static int imx6_setup_phy_mpll(struct imx6_pcie *imx6_pcie)
int mult, div;
u32 val;

- if (imx6_pcie->variant == IMX7D)
+ if (imx6_pcie->variant == IMX7D ||
+ imx6_pcie->variant == IMX8MQ)
return 0;

switch (phy_rate) {
@@ -616,6 +682,7 @@ static void imx6_pcie_ltssm_enable(struct device *dev)
IMX6Q_GPR12_PCIE_CTL_2);
break;
case IMX7D:
+ case IMX8MQ: /* FALLTHROUGH */
reset_control_deassert(imx6_pcie->apps_reset);
break;
}
@@ -870,6 +937,10 @@ static int imx6_pcie_probe(struct platform_device *pdev)
imx6_pcie->variant =
(enum imx6_pcie_variants)of_device_get_match_data(dev);

+ if (of_property_read_u32(node, "fsl,controller-id",
+ &imx6_pcie->controller_id))
+ imx6_pcie->controller_id = 0;
+
dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
pci->dbi_base = devm_ioremap_resource(dev, dbi_base);
if (IS_ERR(pci->dbi_base))
@@ -921,7 +992,8 @@ static int imx6_pcie_probe(struct platform_device *pdev)
return PTR_ERR(imx6_pcie->pcie_inbound_axi);
}
break;
- case IMX7D:
+ case IMX8MQ:
+ case IMX7D: /* FALLTHROUGH */
imx6_pcie->pciephy_reset = devm_reset_control_get_exclusive(dev,
"pciephy");
if (IS_ERR(imx6_pcie->pciephy_reset)) {
@@ -1011,6 +1083,7 @@ static const struct of_device_id imx6_pcie_of_match[] = {
{ .compatible = "fsl,imx6sx-pcie", .data = (void *)IMX6SX, },
{ .compatible = "fsl,imx6qp-pcie", .data = (void *)IMX6QP, },
{ .compatible = "fsl,imx7d-pcie", .data = (void *)IMX7D, },
+ { .compatible = "fsl,imx8mq-pcie", .data = (void *)IMX8MQ, } ,
{},
};

@@ -1027,6 +1100,7 @@ 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
@@ -1036,6 +1110,7 @@ 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);
}
--
2.19.1