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PCI: imx6: Separate PERST# assertion from core reset functions

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The imx_pcie_assert_core_reset() and imx_pcie_deassert_core_reset()
functions are primarily intended to reset the RC controller itself, not
the remote PCIe endpoint devices. However, the PERST# GPIO control was
previously embedded within these functions, which conflates two distinct
reset operations.

Move the PERST# GPIO handling into a dedicated function
imx_pcie_assert_perst(). This makes the code more maintainable and
prepares for parsing the reset-gpios property according to the new
Root Port DT binding in subsequent patches.

No functional change is intended.

Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Richard Zhu <hongxing.zhu@nxp.com>
Link: https://patch.msgid.link/20260306030456.1032815-1-sherry.sun@nxp.com
This commit is contained in:
Sherry Sun 2026-03-06 11:04:56 +08:00 committed by Manivannan Sadhasivam
parent 192b8a1bf8
commit 180ea823bb
1 changed files with 18 additions and 11 deletions
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29
drivers/pci/controller/dwc/pci-imx6.c
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@ -901,9 +901,6 @@ static void imx_pcie_assert_core_reset(struct imx_pcie *imx_pcie)
if (imx_pcie->drvdata->core_reset)
imx_pcie->drvdata->core_reset(imx_pcie, true);
/* Some boards don't have PCIe reset GPIO. */
gpiod_set_value_cansleep(imx_pcie->reset_gpiod, 1);
}
static void imx_pcie_deassert_core_reset(struct imx_pcie *imx_pcie)
@ -912,14 +909,6 @@ static void imx_pcie_deassert_core_reset(struct imx_pcie *imx_pcie)
if (imx_pcie->drvdata->core_reset)
imx_pcie->drvdata->core_reset(imx_pcie, false);
/* Some boards don't have PCIe reset GPIO. */
if (imx_pcie->reset_gpiod) {
msleep(100);
gpiod_set_value_cansleep(imx_pcie->reset_gpiod, 0);
/* Wait for 100ms after PERST# deassertion (PCIe r5.0, 6.6.1) */
msleep(100);
}
}
static int imx_pcie_wait_for_speed_change(struct imx_pcie *imx_pcie)
@ -1231,6 +1220,19 @@ static void imx_pcie_disable_device(struct pci_host_bridge *bridge,
imx_pcie_remove_lut(imx_pcie, pci_dev_id(pdev));
}
static void imx_pcie_assert_perst(struct imx_pcie *imx_pcie, bool assert)
{
if (assert) {
gpiod_set_value_cansleep(imx_pcie->reset_gpiod, 1);
} else {
if (imx_pcie->reset_gpiod) {
msleep(PCIE_T_PVPERL_MS);
gpiod_set_value_cansleep(imx_pcie->reset_gpiod, 0);
msleep(PCIE_RESET_CONFIG_WAIT_MS);
}
}
}
static int imx_pcie_host_init(struct dw_pcie_rp *pp)
{
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
@ -1253,6 +1255,7 @@ static int imx_pcie_host_init(struct dw_pcie_rp *pp)
}
imx_pcie_assert_core_reset(imx_pcie);
imx_pcie_assert_perst(imx_pcie, true);
if (imx_pcie->drvdata->init_phy)
imx_pcie->drvdata->init_phy(imx_pcie);
@ -1291,6 +1294,7 @@ static int imx_pcie_host_init(struct dw_pcie_rp *pp)
imx_pcie_ltssm_disable(dev);
imx_pcie_deassert_core_reset(imx_pcie);
imx_pcie_assert_perst(imx_pcie, false);
if (imx_pcie->drvdata->wait_pll_lock) {
ret = imx_pcie->drvdata->wait_pll_lock(imx_pcie);
@ -1587,6 +1591,7 @@ static int imx_pcie_suspend_noirq(struct device *dev)
* clock which saves some power.
*/
imx_pcie_assert_core_reset(imx_pcie);
imx_pcie_assert_perst(imx_pcie, true);
imx_pcie->drvdata->enable_ref_clk(imx_pcie, false);
} else {
return dw_pcie_suspend_noirq(imx_pcie->pci);
@ -1608,6 +1613,7 @@ static int imx_pcie_resume_noirq(struct device *dev)
if (ret)
return ret;
imx_pcie_deassert_core_reset(imx_pcie);
imx_pcie_assert_perst(imx_pcie, false);
/*
* Using PCIE_TEST_PD seems to disable MSI and powers down the
@ -1845,6 +1851,7 @@ static void imx_pcie_shutdown(struct platform_device *pdev)
/* bring down link, so bootloader gets clean state in case of reboot */
imx_pcie_assert_core_reset(imx_pcie);
imx_pcie_assert_perst(imx_pcie, true);
}
static const struct imx_pcie_drvdata drvdata[] = {