[PATCH v10 03/14] PCI: imx6: Simplify reset handling by using by using *_FLAG_HAS_*_RESET

Frank Li
2024-02-05T17:34:12Z

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: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---

Notes:
Change from v4 to v5:
- Add Mani's Reviewed-by tag
- Fixed MQ_EP's flags

Chagne from v3 to v4:
- none
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 | 105 ++++++++++----------------
1 file changed, 39 insertions(+), 66 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 59f117f855c26..a1653b58051b7 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -61,6 +61,8 @@ enum imx6_pcie_variants {
#define IMX6_PCIE_FLAG_IMX6_SPEED_CHANGE BIT(1)
#define IMX6_PCIE_FLAG_SUPPORTS_SUSPEND BIT(2)
#define IMX6_PCIE_FLAG_HAS_PHYDRV BIT(3)
+#define IMX6_PCIE_FLAG_HAS_APP_RESET BIT(4)
+#define IMX6_PCIE_FLAG_HAS_PHY_RESET BIT(5)

#define imx6_check_flag(pci, val) (pci->drvdata->flags & val)

@@ -661,18 +663,10 @@ 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,
@@ -693,6 +687,8 @@ 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. */
@@ -706,14 +702,10 @@ 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.
@@ -745,11 +737,7 @@ 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;
}

@@ -796,16 +784,11 @@ 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)
@@ -819,16 +802,11 @@ 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)
@@ -1287,38 +1265,26 @@ static int imx6_pcie_probe(struct platform_device *pdev)
"failed to get pcie phy\n");
}

+ 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");
+ }
+
+ 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 IMX8MQ:
case IMX8MQ_EP:
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 (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;
default:
break;
}
@@ -1448,13 +1414,17 @@ 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",
.clk_names = imx6q_clks,
.clks_cnt = ARRAY_SIZE(imx6q_clks),
},
[IMX8MQ] = {
.variant = IMX8MQ,
+ .flags = IMX6_PCIE_FLAG_HAS_APP_RESET |
+ IMX6_PCIE_FLAG_HAS_PHY_RESET,
.gpr = "fsl,imx8mq-iomuxc-gpr",
.clk_names = imx8mq_clks,
.clks_cnt = ARRAY_SIZE(imx8mq_clks),
@@ -1471,13 +1441,16 @@ static const struct imx6_pcie_drvdata drvdata[] = {
[IMX8MP] = {
.variant = IMX8MP,
.flags = IMX6_PCIE_FLAG_SUPPORTS_SUSPEND |
- IMX6_PCIE_FLAG_HAS_PHYDRV,
+ IMX6_PCIE_FLAG_HAS_PHYDRV |
+ IMX6_PCIE_FLAG_HAS_APP_RESET,
.gpr = "fsl,imx8mp-iomuxc-gpr",
.clk_names = imx8mm_clks,
.clks_cnt = ARRAY_SIZE(imx8mm_clks),
},
[IMX8MQ_EP] = {
.variant = IMX8MQ_EP,
+ .flags = IMX6_PCIE_FLAG_HAS_APP_RESET |
+ IMX6_PCIE_FLAG_HAS_PHY_RESET,
.mode = DW_PCIE_EP_TYPE,
.gpr = "fsl,imx8mq-iomuxc-gpr",
.clk_names = imx8mq_clks,
--
2.34.1