diff mbox series

[3/9] PCI: imx6: Simplify reset handling by using by using *_FLAG_HAS_*_RESET

Message ID 20231206155903.566194-4-Frank.Li@nxp.com (mailing list archive)
State Superseded
Headers show
Series PCI: imx6: Clean up and add imx95 pci support | expand

Commit Message

Frank Li Dec. 6, 2023, 3:58 p.m. UTC 
Refactors the reset handling logic in the imx6 PCI driver by adding
IMX6_PCIE_FLAG_HAS_*_RESET bitmask define for drvdata::flags.

The drvdata::flags and a bitmask ensures a cleaner and more scalable
switch-case structure for handling reset.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/pci/controller/dwc/pci-imx6.c | 115 +++++++++++---------------
 1 file changed, 47 insertions(+), 68 deletions(-)

Comments

Philipp Zabel Dec. 6, 2023, 4:52 p.m. UTC | #1 
Hi Frank,

On Mi, 2023-12-06 at 10:58 -0500, Frank Li wrote:
> Refactors the reset handling logic in the imx6 PCI driver by adding
> IMX6_PCIE_FLAG_HAS_*_RESET bitmask define for drvdata::flags.
> 
> The drvdata::flags and a bitmask ensures a cleaner and more scalable
> switch-case structure for handling reset.
> 
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
>  drivers/pci/controller/dwc/pci-imx6.c | 115 +++++++++++---------------
>  1 file changed, 47 insertions(+), 68 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index bcf52aa86462..62d77fabd82a 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
[...]
> @@ -696,18 +698,13 @@ static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
>  
>  static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
>  {
> -	switch (imx6_pcie->drvdata->variant) {
> -	case IMX7D:
> -	case IMX8MQ:
> -	case IMX8MQ_EP:
> +	if (imx6_check_flag(imx6_pcie, IMX6_PCIE_FLAG_HAS_PHY_RESET))

This check is not strictly necessary. If the flag is not set,
imx6_pcie->pciephy_reset is guaranteed to be NULL, and then
reset_control_assert() is a no-op. Same for the other (de)assert
calls below.

[...]

> @@ -1335,36 +1319,24 @@ static int imx6_pcie_probe(struct platform_device *pdev)
>  					     "failed to get pcie phy\n");
>  	}
>  
> -	switch (imx6_pcie->drvdata->variant) {
> -	case IMX7D:
> -		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)) {
> -			dev_err(dev, "Failed to get PCIEPHY reset control\n");
> -			return PTR_ERR(imx6_pcie->pciephy_reset);
> -		}
> -
> -		imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev,
> -									 "apps");
> -		if (IS_ERR(imx6_pcie->apps_reset)) {
> -			dev_err(dev, "Failed to get PCIE APPS reset control\n");
> -			return PTR_ERR(imx6_pcie->apps_reset);
> -		}
> -		break;
> -	case IMX8MM:
> -	case IMX8MM_EP:
> -	case IMX8MP:
> -	case IMX8MP_EP:
> -		imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev,
> -									 "apps");
> +	if (imx6_check_flag(imx6_pcie, IMX6_PCIE_FLAG_HAS_APP_RESET)) {
> +		imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev, "apps");
[...]

I wonder whether we should just defer the check whether apps/pciephy
resets should be used to the device tree validation, and make this an
unconditional call to get an optional reset control:

	imx6_pcie->apps_reset = devm_reset_control_get_optional_exclusive(dev, "apps");

regards
Philipp
Frank Li Dec. 7, 2023, 5:10 p.m. UTC | #2 
On Wed, Dec 06, 2023 at 05:52:23PM +0100, Philipp Zabel wrote:
> Hi Frank,
> 
> On Mi, 2023-12-06 at 10:58 -0500, Frank Li wrote:
> > Refactors the reset handling logic in the imx6 PCI driver by adding
> > IMX6_PCIE_FLAG_HAS_*_RESET bitmask define for drvdata::flags.
> > 
> > The drvdata::flags and a bitmask ensures a cleaner and more scalable
> > switch-case structure for handling reset.
> > 
> > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > ---
> >  drivers/pci/controller/dwc/pci-imx6.c | 115 +++++++++++---------------
> >  1 file changed, 47 insertions(+), 68 deletions(-)
> > 
> > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> > index bcf52aa86462..62d77fabd82a 100644
> > --- a/drivers/pci/controller/dwc/pci-imx6.c
> > +++ b/drivers/pci/controller/dwc/pci-imx6.c
> [...]
> > @@ -696,18 +698,13 @@ static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
> >  
> >  static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
> >  {
> > -	switch (imx6_pcie->drvdata->variant) {
> > -	case IMX7D:
> > -	case IMX8MQ:
> > -	case IMX8MQ_EP:
> > +	if (imx6_check_flag(imx6_pcie, IMX6_PCIE_FLAG_HAS_PHY_RESET))
> 
> This check is not strictly necessary. If the flag is not set,
> imx6_pcie->pciephy_reset is guaranteed to be NULL, and then
> reset_control_assert() is a no-op. Same for the other (de)assert
> calls below.
> 
> [...]
> 
> > @@ -1335,36 +1319,24 @@ static int imx6_pcie_probe(struct platform_device *pdev)
> >  					     "failed to get pcie phy\n");
> >  	}
> >  
> > -	switch (imx6_pcie->drvdata->variant) {
> > -	case IMX7D:
> > -		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)) {
> > -			dev_err(dev, "Failed to get PCIEPHY reset control\n");
> > -			return PTR_ERR(imx6_pcie->pciephy_reset);
> > -		}
> > -
> > -		imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev,
> > -									 "apps");
> > -		if (IS_ERR(imx6_pcie->apps_reset)) {
> > -			dev_err(dev, "Failed to get PCIE APPS reset control\n");
> > -			return PTR_ERR(imx6_pcie->apps_reset);
> > -		}
> > -		break;
> > -	case IMX8MM:
> > -	case IMX8MM_EP:
> > -	case IMX8MP:
> > -	case IMX8MP_EP:
> > -		imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev,
> > -									 "apps");
> > +	if (imx6_check_flag(imx6_pcie, IMX6_PCIE_FLAG_HAS_APP_RESET)) {
> > +		imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev, "apps");
> [...]
> 
> I wonder whether we should just defer the check whether apps/pciephy
> resets should be used to the device tree validation, and make this an
> unconditional call to get an optional reset control:
> 
> 	imx6_pcie->apps_reset = devm_reset_control_get_optional_exclusive(dev, "apps");

I think double check here is neccesary. No sure if dts file version
binding yaml was exactly matched driver. Sometime user use old version dts. 
Double check here will help identify the dts problem. 

Frank 
> 
> regards
> Philipp
Philipp Zabel Dec. 8, 2023, 11:49 a.m. UTC | #3 
On Do, 2023-12-07 at 12:10 -0500, Frank Li wrote:
> On Wed, Dec 06, 2023 at 05:52:23PM +0100, Philipp Zabel wrote:
[...]
> > I wonder whether we should just defer the check whether apps/pciephy
> > resets should be used to the device tree validation, and make this an
> > unconditional call to get an optional reset control:
> > 
> > 	imx6_pcie->apps_reset = devm_reset_control_get_optional_exclusive(dev, "apps");
> 
> I think double check here is neccesary. No sure if dts file version
> binding yaml was exactly matched driver. Sometime user use old version dts. 
> Double check here will help identify the dts problem. 

Makes sense to me,

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

regards
Philipp
diff mbox series

Patch

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index bcf52aa86462..62d77fabd82a 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -63,6 +63,8 @@  enum imx6_pcie_variants {
 #define IMX6_PCIE_FLAG_HAS_CLK_INBOUND_AXI	BIT(3)
 #define IMX6_PCIE_FLAG_HAS_CLK_AUX		BIT(4)
 #define IMX6_PCIE_FLAG_HAS_PHY			BIT(5)
+#define IMX6_PCIE_FLAG_HAS_APP_RESET		BIT(6)
+#define IMX6_PCIE_FLAG_HAS_PHY_RESET		BIT(7)
 
 #define imx6_check_flag(pci, val)	(pci->drvdata->flags & val)
 
@@ -696,18 +698,13 @@  static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
 
 static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
 {
-	switch (imx6_pcie->drvdata->variant) {
-	case IMX7D:
-	case IMX8MQ:
-	case IMX8MQ_EP:
+	if (imx6_check_flag(imx6_pcie, IMX6_PCIE_FLAG_HAS_PHY_RESET))
 		reset_control_assert(imx6_pcie->pciephy_reset);
-		fallthrough;
-	case IMX8MM:
-	case IMX8MM_EP:
-	case IMX8MP:
-	case IMX8MP_EP:
+
+	if (imx6_check_flag(imx6_pcie, IMX6_PCIE_FLAG_HAS_APP_RESET))
 		reset_control_assert(imx6_pcie->apps_reset);
-		break;
+
+	switch (imx6_pcie->drvdata->variant) {
 	case IMX6SX:
 		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
 				   IMX6SX_GPR12_PCIE_TEST_POWERDOWN,
@@ -728,6 +725,8 @@  static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
 		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
 				   IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);
 		break;
+	default:
+		break;
 	}
 
 	/* Some boards don't have PCIe reset GPIO. */
@@ -741,14 +740,11 @@  static int imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
 	struct dw_pcie *pci = imx6_pcie->pci;
 	struct device *dev = pci->dev;
 
-	switch (imx6_pcie->drvdata->variant) {
-	case IMX8MQ:
-	case IMX8MQ_EP:
-		reset_control_deassert(imx6_pcie->pciephy_reset);
-		break;
-	case IMX7D:
+	if (imx6_check_flag(imx6_pcie, IMX6_PCIE_FLAG_HAS_PHY_RESET))
 		reset_control_deassert(imx6_pcie->pciephy_reset);
 
+	switch (imx6_pcie->drvdata->variant) {
+	case IMX7D:
 		/* Workaround for ERR010728, failure of PCI-e PLL VCO to
 		 * oscillate, especially when cold.  This turns off "Duty-cycle
 		 * Corrector" and other mysterious undocumented things.
@@ -780,11 +776,7 @@  static int imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
 
 		usleep_range(200, 500);
 		break;
-	case IMX6Q:		/* Nothing to do */
-	case IMX8MM:
-	case IMX8MM_EP:
-	case IMX8MP:
-	case IMX8MP_EP:
+	default:
 		break;
 	}
 
@@ -831,16 +823,12 @@  static void imx6_pcie_ltssm_enable(struct device *dev)
 				   IMX6Q_GPR12_PCIE_CTL_2,
 				   IMX6Q_GPR12_PCIE_CTL_2);
 		break;
-	case IMX7D:
-	case IMX8MQ:
-	case IMX8MQ_EP:
-	case IMX8MM:
-	case IMX8MM_EP:
-	case IMX8MP:
-	case IMX8MP_EP:
-		reset_control_deassert(imx6_pcie->apps_reset);
+	default:
 		break;
 	}
+
+	if (imx6_check_flag(imx6_pcie, IMX6_PCIE_FLAG_HAS_APP_RESET))
+		reset_control_deassert(imx6_pcie->apps_reset);
 }
 
 static void imx6_pcie_ltssm_disable(struct device *dev)
@@ -854,16 +842,12 @@  static void imx6_pcie_ltssm_disable(struct device *dev)
 		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
 				   IMX6Q_GPR12_PCIE_CTL_2, 0);
 		break;
-	case IMX7D:
-	case IMX8MQ:
-	case IMX8MQ_EP:
-	case IMX8MM:
-	case IMX8MM_EP:
-	case IMX8MP:
-	case IMX8MP_EP:
-		reset_control_assert(imx6_pcie->apps_reset);
+	default:
 		break;
 	}
+
+	if (imx6_check_flag(imx6_pcie, IMX6_PCIE_FLAG_HAS_APP_RESET))
+		reset_control_assert(imx6_pcie->apps_reset);
 }
 
 static int imx6_pcie_start_link(struct dw_pcie *pci)
@@ -1335,36 +1319,24 @@  static int imx6_pcie_probe(struct platform_device *pdev)
 					     "failed to get pcie phy\n");
 	}
 
-	switch (imx6_pcie->drvdata->variant) {
-	case IMX7D:
-		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)) {
-			dev_err(dev, "Failed to get PCIEPHY reset control\n");
-			return PTR_ERR(imx6_pcie->pciephy_reset);
-		}
-
-		imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev,
-									 "apps");
-		if (IS_ERR(imx6_pcie->apps_reset)) {
-			dev_err(dev, "Failed to get PCIE APPS reset control\n");
-			return PTR_ERR(imx6_pcie->apps_reset);
-		}
-		break;
-	case IMX8MM:
-	case IMX8MM_EP:
-	case IMX8MP:
-	case IMX8MP_EP:
-		imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev,
-									 "apps");
+	if (imx6_check_flag(imx6_pcie, IMX6_PCIE_FLAG_HAS_APP_RESET)) {
+		imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev, "apps");
 		if (IS_ERR(imx6_pcie->apps_reset))
 			return dev_err_probe(dev, PTR_ERR(imx6_pcie->apps_reset),
 					     "failed to get pcie apps reset control\n");
+	}
 
-		break;
+	if (imx6_check_flag(imx6_pcie, IMX6_PCIE_FLAG_HAS_PHY_RESET)) {
+		imx6_pcie->pciephy_reset = devm_reset_control_get_exclusive(dev, "pciephy");
+		if (IS_ERR(imx6_pcie->pciephy_reset))
+			return dev_err_probe(dev, PTR_ERR(imx6_pcie->pciephy_reset),
+					     "Failed to get PCIEPHY reset control\n");
+	}
+
+	switch (imx6_pcie->drvdata->variant) {
+	case IMX7D:
+		if (dbi_base->start == IMX8MQ_PCIE2_BASE_ADDR)
+			imx6_pcie->controller_id = 1;
 	default:
 		break;
 	}
@@ -1492,32 +1464,39 @@  static const struct imx6_pcie_drvdata drvdata[] = {
 	},
 	[IMX7D] = {
 		.variant = IMX7D,
-		.flags = IMX6_PCIE_FLAG_SUPPORTS_SUSPEND,
+		.flags = IMX6_PCIE_FLAG_SUPPORTS_SUSPEND |
+			 IMX6_PCIE_FLAG_HAS_APP_RESET |
+			 IMX6_PCIE_FLAG_HAS_PHY_RESET,
 		.gpr = "fsl,imx7d-iomuxc-gpr",
 	},
 	[IMX8MQ] = {
 		.variant = IMX8MQ,
-		.flags = IMX6_PCIE_FLAG_HAS_CLK_AUX,
+		.flags = IMX6_PCIE_FLAG_HAS_CLK_AUX |
+			 IMX6_PCIE_FLAG_HAS_APP_RESET |
+			 IMX6_PCIE_FLAG_HAS_PHY_RESET,
 		.gpr = "fsl,imx8mq-iomuxc-gpr",
 	},
 	[IMX8MM] = {
 		.variant = IMX8MM,
 		.flags = IMX6_PCIE_FLAG_SUPPORTS_SUSPEND |
 			 IMX6_PCIE_FLAG_HAS_CLK_AUX |
-			 IMX6_PCIE_FLAG_HAS_PHY,
+			 IMX6_PCIE_FLAG_HAS_PHY |
+			 IMX6_PCIE_FLAG_HAS_APP_RESET,
 		.gpr = "fsl,imx8mm-iomuxc-gpr",
 	},
 	[IMX8MP] = {
 		.variant = IMX8MP,
 		.flags = IMX6_PCIE_FLAG_SUPPORTS_SUSPEND |
 			 IMX6_PCIE_FLAG_HAS_CLK_AUX |
-			 IMX6_PCIE_FLAG_HAS_PHY,
+			 IMX6_PCIE_FLAG_HAS_PHY |
+			 IMX6_PCIE_FLAG_HAS_APP_RESET,
 		.gpr = "fsl,imx8mp-iomuxc-gpr",
 	},
 	[IMX8MQ_EP] = {
 		.variant = IMX8MQ_EP,
 		.flags = IMX6_PCIE_FLAG_HAS_CLK_AUX |
-			 IMX6_PCIE_FLAG_HAS_PHY,
+			 IMX6_PCIE_FLAG_HAS_PHY |
+			 IMX6_PCIE_FLAG_HAS_PHY_RESET,
 		.mode = DW_PCIE_EP_TYPE,
 		.gpr = "fsl,imx8mq-iomuxc-gpr",
 	},