diff mbox

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

Message ID 20170206151716.10381-4-andrew.smirnov@gmail.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Andrey Smirnov Feb. 6, 2017, 3:17 p.m. UTC 
Add various bits of code needed to support i.MX7D variant of the IP.

Cc: yurovsky@gmail.com
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
 .../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(-)

Comments

Lucas Stach Feb. 6, 2017, 3:33 p.m. UTC | #1 
Am Montag, den 06.02.2017, 07:17 -0800 schrieb Andrey Smirnov:
> Add various bits of code needed to support i.MX7D variant of the IP.
> 
> Cc: yurovsky@gmail.com
> Cc: Lucas Stach <l.stach@pengutronix.de>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Fabio Estevam <fabio.estevam@nxp.com>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Lee Jones <lee.jones@linaro.org>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>

Two small comments inline, otherwise looks real good now.

> ---
>  .../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.

This misses an "Additional required properties for imx7d-pcie" section
listing the required reset handles.

> 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

[...]

>  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);

Can this reset assertion be moved into imx6_pcie_assert_core_reset()?
This may change the programming order slightly from the downstream
driver, but I guess that won't hurt if this is the equivalent of the
LTSSM enable signal.

Regards,
Lucas
Andrey Smirnov Feb. 6, 2017, 7:18 p.m. UTC | #2 
On Mon, Feb 6, 2017 at 7:33 AM, Lucas Stach <l.stach@pengutronix.de> wrote:
> Am Montag, den 06.02.2017, 07:17 -0800 schrieb Andrey Smirnov:
>> Add various bits of code needed to support i.MX7D variant of the IP.
>>
>> Cc: yurovsky@gmail.com
>> Cc: Lucas Stach <l.stach@pengutronix.de>
>> Cc: Bjorn Helgaas <bhelgaas@google.com>
>> Cc: Fabio Estevam <fabio.estevam@nxp.com>
>> Cc: Rob Herring <robh+dt@kernel.org>
>> Cc: Mark Rutland <mark.rutland@arm.com>
>> Cc: Lee Jones <lee.jones@linaro.org>
>> Cc: linux-arm-kernel@lists.infradead.org
>> Cc: devicetree@vger.kernel.org
>> Cc: linux-kernel@vger.kernel.org
>> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
>
> Two small comments inline, otherwise looks real good now.
>
>> ---
>>  .../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.
>
> This misses an "Additional required properties for imx7d-pcie" section
> listing the required reset handles.

Darn! Forgot to update this part. Will fix in v4.

>
>> 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
>
> [...]
>
>>  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);
>
> Can this reset assertion be moved into imx6_pcie_assert_core_reset()?
> This may change the programming order slightly from the downstream
> driver, but I guess that won't hurt if this is the equivalent of the
> LTSSM enable signal.

I don't see why it wouldn't be possible to move it. I'll give it a try
on a real HW and update v4 accordingly.

Thanks,
Andrey Smirnov
diff mbox

Patch

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 */