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Merge branch 'pci/controller/mediatek-gen3'

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- Deassert PCIE_PHY_RSTB so REFCLK is stable for at least 100ms
  (PCIE_T_PVPERL_MS) before deasserting PERST# (Jian Yang)

- Add .shutdown() to assert PERST# before powering down device (Jian Yang)

- Do full device power down on removal, including asserting PERST#, when
  removing driver (Chen-Yu Tsai)

- Fix a 'failed to create pwrctrl devices' error message that was
  inadvertently skipped (Chen-Yu Tsai)

* pci/controller/mediatek-gen3:
  PCI: mediatek-gen3: Fix incorrectly skipped pwrctrl error message
  PCI: mediatek-gen3: Do full device power down on removal
  PCI: mediatek-gen3: Add a .shutdown() callback to control PERST# signal
  PCI: mediatek-gen3: Fix PERST# control timing during system startup
This commit is contained in:
Bjorn Helgaas 2026-06-23 17:32:16 -05:00
commit 4e38ddba80
1 changed files with 34 additions and 5 deletions
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39
drivers/pci/controller/pcie-mediatek-gen3.c
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@ -63,6 +63,12 @@
#define PCIE_BRG_RSTB BIT(2)
#define PCIE_PE_RSTB BIT(3)
/*
* As described in the datasheet of MediaTek PCIe Gen3 controller, wait 10ms
* after setting PCIE_BRG_RSTB, and before accessing PCIe internal registers.
*/
#define PCIE_BRG_RST_RDY_MS 10
#define PCIE_LTSSM_STATUS_REG 0x150
#define PCIE_LTSSM_STATE_MASK GENMASK(28, 24)
#define PCIE_LTSSM_STATE(val) ((val & PCIE_LTSSM_STATE_MASK) >> 24)
@ -430,6 +436,21 @@ static int mtk_pcie_devices_power_up(struct mtk_gen3_pcie *pcie)
return err;
}
/*
* Some of MediaTek's chips won't output REFCLK when PCIE_PHY_RSTB is
* asserted, we have to de-assert MAC & PHY & BRG reset signals first
* to allow the REFCLK to be stable. While PCIE_BRG_RSTB is asserted,
* there is a short period during which the PCIe internal register
* cannot be accessed, so we need to wait 10ms here.
*/
msleep(PCIE_BRG_RST_RDY_MS);
if (!(pcie->soc->flags & SKIP_PCIE_RSTB)) {
/* De-assert MAC, PHY and BRG reset signals */
val &= ~(PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB);
writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG);
}
/*
* Described in PCIe CEM specification revision 6.0.
*
@ -439,9 +460,8 @@ static int mtk_pcie_devices_power_up(struct mtk_gen3_pcie *pcie)
msleep(PCIE_T_PVPERL_MS);
if (!(pcie->soc->flags & SKIP_PCIE_RSTB)) {
/* De-assert reset signals */
val &= ~(PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB |
PCIE_PE_RSTB);
/* De-assert PERST# signal */
val &= ~PCIE_PE_RSTB;
writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG);
}
@ -1222,8 +1242,8 @@ static int mtk_pcie_probe(struct platform_device *pdev)
err = pci_pwrctrl_create_devices(pcie->dev);
if (err) {
goto err_tear_down_irq;
dev_err_probe(dev, err, "failed to create pwrctrl devices\n");
goto err_tear_down_irq;
}
err = mtk_pcie_setup(pcie);
@ -1260,12 +1280,20 @@ static void mtk_pcie_remove(struct platform_device *pdev)
pci_remove_root_bus(host->bus);
pci_unlock_rescan_remove();
pci_pwrctrl_power_off_devices(pcie->dev);
mtk_pcie_devices_power_down(pcie);
mtk_pcie_power_down(pcie);
pci_pwrctrl_destroy_devices(pcie->dev);
mtk_pcie_irq_teardown(pcie);
}
static void mtk_pcie_shutdown(struct platform_device *pdev)
{
struct mtk_gen3_pcie *pcie = platform_get_drvdata(pdev);
mtk_pcie_devices_power_down(pcie);
mtk_pcie_power_down(pcie);
}
static void mtk_pcie_irq_save(struct mtk_gen3_pcie *pcie)
{
int i;
@ -1404,6 +1432,7 @@ MODULE_DEVICE_TABLE(of, mtk_pcie_of_match);
static struct platform_driver mtk_pcie_driver = {
.probe = mtk_pcie_probe,
.remove = mtk_pcie_remove,
.shutdown = mtk_pcie_shutdown,
.driver = {
.name = "mtk-pcie-gen3",
.of_match_table = mtk_pcie_of_match,