[PATCH v3 03/13] PCI: imx6: Simplify reset handling by using by using *_FLAG_HAS_*_RESET

From: Frank Li
Date: Mon Dec 11 2023 - 16:59:47 EST


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.

Reviewed-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---

Notes:
Change from v2 to v3:
- add Philipp's Reviewed-by tag
Change from v1 to v2:
- remove condition check before reset_control_(de)assert() because it is
none ops if a NULL pointer pass down.
- still keep condition check at probe to help identify dts file mismatch
problem.

Change from v1 to v2:
- remove condition check before reset_control_(de)assert() because it is
none ops if a NULL pointer pass down.
- still keep condition check at probe to help identify dts file mismatch
problem.

drivers/pci/controller/dwc/pci-imx6.c | 111 ++++++++++----------------
1 file changed, 42 insertions(+), 69 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index bcf52aa86462e..509d459bdc5a1 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 +698,10 @@ static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)

static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
{
+ reset_control_assert(imx6_pcie->pciephy_reset);
+ reset_control_assert(imx6_pcie->apps_reset);
+
switch (imx6_pcie->drvdata->variant) {
- case IMX7D:
- case IMX8MQ:
- case IMX8MQ_EP:
- reset_control_assert(imx6_pcie->pciephy_reset);
- fallthrough;
- case IMX8MM:
- case IMX8MM_EP:
- case IMX8MP:
- case IMX8MP_EP:
- reset_control_assert(imx6_pcie->apps_reset);
- break;
case IMX6SX:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6SX_GPR12_PCIE_TEST_POWERDOWN,
@@ -728,6 +722,8 @@ 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 +737,10 @@ static int imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
struct dw_pcie *pci = imx6_pcie->pci;
struct device *dev = pci->dev;

+ reset_control_deassert(imx6_pcie->pciephy_reset);
+
switch (imx6_pcie->drvdata->variant) {
- case IMX8MQ:
- case IMX8MQ_EP:
- reset_control_deassert(imx6_pcie->pciephy_reset);
- break;
case IMX7D:
- reset_control_deassert(imx6_pcie->pciephy_reset);
-
/* 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 +772,7 @@ 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 +819,11 @@ 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;
}
+
+ reset_control_deassert(imx6_pcie->apps_reset);
}

static void imx6_pcie_ltssm_disable(struct device *dev)
@@ -854,16 +837,11 @@ 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;
}
+
+ reset_control_assert(imx6_pcie->apps_reset);
}

static int imx6_pcie_start_link(struct dw_pcie *pci)
@@ -1335,36 +1313,24 @@ 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 +1458,39 @@ 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",
},
--
2.34.1