[PATCH v4 3/3] PCI: imx6: Add code to support i.MX7D

Lee Jones lee.jones at linaro.org
Wed Feb 8 04:21:03 PST 2017


On Tue, 07 Feb 2017, Andrey Smirnov wrote:

> Add various bits of code needed to support i.MX7D variant of the IP.
> 
> Cc: yurovsky at gmail.com
> Cc: Lucas Stach <l.stach at pengutronix.de>
> Cc: Bjorn Helgaas <bhelgaas at google.com>
> Cc: Rob Herring <robh+dt at kernel.org>
> Cc: Mark Rutland <mark.rutland at arm.com>
> Cc: Lee Jones <lee.jones at linaro.org>
> Cc: Fabio Estevam <fabio.estevam at nxp.com>
> Cc: linux-arm-kernel at lists.infradead.org
> Cc: devicetree at vger.kernel.org
> Cc: linux-kernel at vger.kernel.org
> Signed-off-by: Andrey Smirnov <andrew.smirnov at gmail.com>
> ---
>  .../devicetree/bindings/pci/fsl,imx6q-pcie.txt     |  13 ++-
>  drivers/pci/host/pci-imx6.c                        | 121 ++++++++++++++++-----

>  include/linux/mfd/syscon/imx7-iomuxc-gpr.h         |   4 +

Acked-by: Lee Jones <lee.jones at linaro.org>

>  3 files changed, 112 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..11db2ab 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.
> @@ -34,6 +38,13 @@ Additional required properties for imx6sx-pcie:
>  - clock names: Must include the following additional entries:
>  	- "pcie_inbound_axi"
>  
> +Additional required properties for imx7d-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
> +- reset-names: Must contain the following entires:
> +  	       - "pciephy"
> +	       - "apps"
> +
>  Example:
>  
>  	pcie at 0x01000000 {
> diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
> index 3ef8093..723805c 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 +261,10 @@ 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);
> +		reset_control_assert(imx6_pcie->apps_reset);
> +		break;
>  	case IMX6SX:
>  		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
>  				   IMX6SX_GPR12_PCIE_TEST_POWERDOWN,
> @@ -333,11 +347,33 @@ 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 +417,10 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
>  	}
>  
>  	switch (imx6_pcie->variant) {
> +	case IMX7D:
> +		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 */

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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