[PATCH v3 3/3] PCI: imx6: Add code to support i.MX7D

From: Andrey Smirnov
Date: Mon Feb 06 2017 - 10:17:53 EST

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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: Fabio Estevam <fabio.estevam@xxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Lee Jones <lee.jones@xxxxxxxxxx>
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 | 6 +-
drivers/pci/host/pci-imx6.c | 121 ++++++++++++++++-----
include/linux/mfd/syscon/imx7-iomuxc-gpr.h | 4 +
3 files changed, 105 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..9f57759 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.
diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
index 3ef8093..34a21c9 100644
--- a/drivers/pci/host/pci-imx6.c
+++ b/drivers/pci/host/pci-imx6.c
@@ -17,6 +17,7 @@
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
+#include <linux/mfd/syscon/imx7-iomuxc-gpr.h>
#include <linux/module.h>
#include <linux/of_gpio.h>
#include <linux/of_device.h>
@@ -27,6 +28,7 @@
#include <linux/signal.h>
#include <linux/types.h>
#include <linux/interrupt.h>
+#include <linux/reset.h>

#include "pcie-designware.h"

@@ -36,6 +38,7 @@ enum imx6_pcie_variants {
IMX6Q,
IMX6SX,
IMX6QP,
+ IMX7D,
};

struct imx6_pcie {
@@ -47,6 +50,8 @@ struct imx6_pcie {
struct clk *pcie_inbound_axi;
struct clk *pcie;
struct regmap *iomuxc_gpr;
+ struct reset_control *pciephy_reset;
+ struct reset_control *apps_reset;
enum imx6_pcie_variants variant;
u32 tx_deemph_gen1;
u32 tx_deemph_gen2_3p5db;
@@ -56,6 +61,11 @@ struct imx6_pcie {
int link_gen;
};

+/* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */
+#define PHY_PLL_LOCK_WAIT_MAX_RETRIES 2000
+#define PHY_PLL_LOCK_WAIT_USLEEP_MIN 50
+#define PHY_PLL_LOCK_WAIT_USLEEP_MAX 200
+
/* PCIe Root Complex registers (memory-mapped) */
#define PCIE_RC_LCR 0x7c
#define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1 0x1
@@ -251,6 +261,9 @@ 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);
+ break;
case IMX6SX:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6SX_GPR12_PCIE_TEST_POWERDOWN,
@@ -333,11 +346,33 @@ static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
break;
+ case IMX7D:
+ break;
}

return ret;
}

+static void imx7d_pcie_wait_for_phy_pll_lock(struct imx6_pcie *imx6_pcie)
+{
+ u32 val;
+ unsigned int retries;
+ struct pcie_port *pp = &imx6_pcie->pp;
+ struct device *dev = pp->dev;
+
+ for (retries = 0; retries < PHY_PLL_LOCK_WAIT_MAX_RETRIES; retries++) {
+ regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR22, &val);
+
+ if (val & IMX7D_GPR22_PCIE_PHY_PLL_LOCKED)
+ return;
+
+ usleep_range(PHY_PLL_LOCK_WAIT_USLEEP_MIN,
+ PHY_PLL_LOCK_WAIT_USLEEP_MAX);
+ }
+
+ dev_err(dev, "PCIe PLL lock timeout\n");
+}
+
static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
{
struct pcie_port *pp = &imx6_pcie->pp;
@@ -381,6 +416,11 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
}

switch (imx6_pcie->variant) {
+ case IMX7D:
+ reset_control_assert(imx6_pcie->apps_reset);
+ reset_control_deassert(imx6_pcie->pciephy_reset);
+ imx7d_pcie_wait_for_phy_pll_lock(imx6_pcie);
+ break;
case IMX6SX:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
IMX6SX_GPR5_PCIE_BTNRST_RESET, 0);
@@ -407,35 +447,44 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)

static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
{
- if (imx6_pcie->variant == IMX6SX)
+ switch (imx6_pcie->variant) {
+ case IMX7D:
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+ IMX7D_GPR12_PCIE_PHY_REFCLK_SEL, 0);
+ break;
+ case IMX6SX:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6SX_GPR12_PCIE_RX_EQ_MASK,
IMX6SX_GPR12_PCIE_RX_EQ_2);
+ /* FALLTHROUGH */
+ default:
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+ IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);

- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
- IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
+ /* configure constant input signal to the pcie ctrl and phy */
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+ IMX6Q_GPR12_LOS_LEVEL, 9 << 4);
+
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+ IMX6Q_GPR8_TX_DEEMPH_GEN1,
+ imx6_pcie->tx_deemph_gen1 << 0);
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+ IMX6Q_GPR8_TX_DEEMPH_GEN2_3P5DB,
+ imx6_pcie->tx_deemph_gen2_3p5db << 6);
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+ IMX6Q_GPR8_TX_DEEMPH_GEN2_6DB,
+ imx6_pcie->tx_deemph_gen2_6db << 12);
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+ IMX6Q_GPR8_TX_SWING_FULL,
+ imx6_pcie->tx_swing_full << 18);
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+ IMX6Q_GPR8_TX_SWING_LOW,
+ imx6_pcie->tx_swing_low << 25);
+ break;
+ }

- /* configure constant input signal to the pcie ctrl and phy */
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,
- IMX6Q_GPR12_LOS_LEVEL, 9 << 4);
-
- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
- IMX6Q_GPR8_TX_DEEMPH_GEN1,
- imx6_pcie->tx_deemph_gen1 << 0);
- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
- IMX6Q_GPR8_TX_DEEMPH_GEN2_3P5DB,
- imx6_pcie->tx_deemph_gen2_3p5db << 6);
- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
- IMX6Q_GPR8_TX_DEEMPH_GEN2_6DB,
- imx6_pcie->tx_deemph_gen2_6db << 12);
- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
- IMX6Q_GPR8_TX_SWING_FULL,
- imx6_pcie->tx_swing_full << 18);
- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
- IMX6Q_GPR8_TX_SWING_LOW,
- imx6_pcie->tx_swing_low << 25);
}

static int imx6_pcie_wait_for_link(struct imx6_pcie *imx6_pcie)
@@ -498,8 +547,11 @@ static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
dw_pcie_writel_rc(pp, PCIE_RC_LCR, tmp);

/* Start LTSSM. */
- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
- IMX6Q_GPR12_PCIE_CTL_2, 1 << 10);
+ if (imx6_pcie->variant == IMX7D)
+ reset_control_deassert(imx6_pcie->apps_reset);
+ else
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+ IMX6Q_GPR12_PCIE_CTL_2, 1 << 10);

ret = imx6_pcie_wait_for_link(imx6_pcie);
if (ret) {
@@ -676,13 +728,31 @@ static int imx6_pcie_probe(struct platform_device *pdev)
return PTR_ERR(imx6_pcie->pcie);
}

- if (imx6_pcie->variant == IMX6SX) {
+ switch (imx6_pcie->variant) {
+ case IMX6SX:
imx6_pcie->pcie_inbound_axi = devm_clk_get(dev,
"pcie_inbound_axi");
if (IS_ERR(imx6_pcie->pcie_inbound_axi)) {
dev_err(dev, "pcie_inbound_axi clock missing or invalid\n");
return PTR_ERR(imx6_pcie->pcie_inbound_axi);
}
+ break;
+ case IMX7D:
+ imx6_pcie->pciephy_reset = devm_reset_control_get(dev,
+ "pciephy");
+ if (IS_ERR(imx6_pcie->pciephy_reset)) {
+ dev_err(dev, "Failed to get PCIEPHY reset contol\n");
+ return PTR_ERR(imx6_pcie->pciephy_reset);
+ }
+
+ imx6_pcie->apps_reset = devm_reset_control_get(dev, "apps");
+ if (IS_ERR(imx6_pcie->apps_reset)) {
+ dev_err(dev, "Failed to get PCIE APPS reset contol\n");
+ return PTR_ERR(imx6_pcie->apps_reset);
+ }
+ break;
+ default:
+ break;
}

/* Grab GPR config register range */
@@ -740,6 +810,7 @@ static const struct of_device_id imx6_pcie_of_match[] = {
{ .compatible = "fsl,imx6q-pcie", .data = (void *)IMX6Q, },
{ .compatible = "fsl,imx6sx-pcie", .data = (void *)IMX6SX, },
{ .compatible = "fsl,imx6qp-pcie", .data = (void *)IMX6QP, },
+ { .compatible = "fsl,imx7d-pcie", .data = (void *)IMX7D, },
{},
};

diff --git a/include/linux/mfd/syscon/imx7-iomuxc-gpr.h b/include/linux/mfd/syscon/imx7-iomuxc-gpr.h
index 4585d61..abbd524 100644
--- a/include/linux/mfd/syscon/imx7-iomuxc-gpr.h
+++ b/include/linux/mfd/syscon/imx7-iomuxc-gpr.h
@@ -44,4 +44,8 @@

#define IMX7D_GPR5_CSI_MUX_CONTROL_MIPI (0x1 << 4)

+#define IMX7D_GPR12_PCIE_PHY_REFCLK_SEL BIT(5)
+
+#define IMX7D_GPR22_PCIE_PHY_PLL_LOCKED BIT(31)
+
#endif /* __LINUX_IMX7_IOMUXC_GPR_H */
--
2.9.3

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In reply to: Andrey Smirnov: "[PATCH v3 2/3] PCI: imx6: Allow probe deferal by reset GPIO"
Next in thread: Lucas Stach: "Re: [PATCH v3 3/3] PCI: imx6: Add code to support i.MX7D"
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