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FROMLIST: PCI: qcom: Handle mixed PERST#/PHY DT configuration #786

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FROMLIST: PCI: qcom: Handle mixed PERST#/PHY DT configuration #786

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FROMLIST: PCI: qcom: Parse PERST# from all PCIe bridge nodes
Mani-Sadhasivam Dec 16, 2025
e8fbbf3
FROMLIST: PCI: qcom: Handle mixed PERST#/PHY DT configuration
qianyu-qcom Jun 30, 2026
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118 changes: 101 additions & 17 deletions drivers/pci/controller/dwc/pcie-qcom.c
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Original file line number Diff line number Diff line change
Expand Up @@ -269,10 +269,15 @@ struct qcom_pcie_cfg {
bool no_l0s;
};

struct qcom_pcie_perst {
struct list_head list;
struct gpio_desc *desc;
};

struct qcom_pcie_port {
struct list_head list;
struct gpio_desc *reset;
struct phy *phy;
struct list_head perst;
};

struct qcom_pcie {
Expand All @@ -285,18 +290,22 @@ struct qcom_pcie {
const struct qcom_pcie_cfg *cfg;
struct dentry *debugfs;
struct list_head ports;
struct gpio_desc *reset;
bool use_pm_opp;
};

#define to_qcom_pcie(x) dev_get_drvdata((x)->dev)

static void __qcom_pcie_perst_assert(struct qcom_pcie *pcie, bool assert)
{
struct qcom_pcie_perst *perst;
struct qcom_pcie_port *port;
int val = assert ? 1 : 0;

list_for_each_entry(port, &pcie->ports, list)
gpiod_set_value_cansleep(port->reset, val);
list_for_each_entry(port, &pcie->ports, list) {
list_for_each_entry(perst, &port->perst, list)
gpiod_set_value_cansleep(perst->desc, val);
}

usleep_range(PERST_DELAY_US, PERST_DELAY_US + 500);
}
Expand Down Expand Up @@ -1762,18 +1771,64 @@ static const struct pci_ecam_ops pci_qcom_ecam_ops = {
}
};

static int qcom_pcie_parse_port(struct qcom_pcie *pcie, struct device_node *node)
/* Parse PERST# from all nodes in depth first manner starting from @np */
static int qcom_pcie_parse_perst(struct qcom_pcie *pcie,
struct qcom_pcie_port *port,
struct device_node *np)
{
struct device *dev = pcie->pci->dev;
struct qcom_pcie_port *port;
struct qcom_pcie_perst *perst;
struct gpio_desc *reset;
struct phy *phy;
int ret;

reset = devm_fwnode_gpiod_get(dev, of_fwnode_handle(node),
"reset", GPIOD_OUT_HIGH, "PERST#");
if (IS_ERR(reset))
if (pcie->reset) {
reset = pcie->reset;
goto skip_perst_parsing;
}

if (!of_find_property(np, "reset-gpios", NULL))
goto parse_child_node;

reset = devm_fwnode_gpiod_get(dev, of_fwnode_handle(np), "reset",
GPIOD_OUT_HIGH, "PERST#");
if (IS_ERR(reset)) {
/*
* FIXME: GPIOLIB currently supports exclusive GPIO access only.
* Non exclusive access is broken. But shared PERST# requires
* non-exclusive access. So once GPIOLIB properly supports it,
* implement it here.
*/
if (PTR_ERR(reset) == -EBUSY)
dev_err(dev, "Shared PERST# is not supported\n");

return PTR_ERR(reset);
}

skip_perst_parsing:
perst = devm_kzalloc(dev, sizeof(*perst), GFP_KERNEL);
if (!perst)
return -ENOMEM;

INIT_LIST_HEAD(&perst->list);
perst->desc = reset;
list_add_tail(&perst->list, &port->perst);

parse_child_node:
for_each_available_child_of_node_scoped(np, child) {
ret = qcom_pcie_parse_perst(pcie, port, child);
if (ret)
return ret;
}

return 0;
}

static int qcom_pcie_parse_port(struct qcom_pcie *pcie, struct device_node *node)
{
struct device *dev = pcie->pci->dev;
struct qcom_pcie_port *port;
struct phy *phy;
int ret;

phy = devm_of_phy_get(dev, node, NULL);
if (IS_ERR(phy))
Expand All @@ -1787,7 +1842,12 @@ static int qcom_pcie_parse_port(struct qcom_pcie *pcie, struct device_node *node
if (ret)
return ret;

port->reset = reset;
INIT_LIST_HEAD(&port->perst);

ret = qcom_pcie_parse_perst(pcie, port, node);
if (ret)
return ret;

port->phy = phy;
INIT_LIST_HEAD(&port->list);
list_add_tail(&port->list, &pcie->ports);
Expand All @@ -1797,9 +1857,18 @@ static int qcom_pcie_parse_port(struct qcom_pcie *pcie, struct device_node *node

static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
{
struct qcom_pcie_perst *perst, *tmp_perst;
struct qcom_pcie_port *port, *tmp_port;
struct device *dev = pcie->pci->dev;
struct qcom_pcie_port *port, *tmp;
int ret = -ENOENT;
int ret = -ENODEV;

if (of_find_property(dev->of_node, "perst-gpios", NULL)) {
pcie->reset = devm_gpiod_get_optional(dev, "perst", GPIOD_OUT_HIGH);
if (IS_ERR(pcie->reset))
return PTR_ERR(pcie->reset);

dev_warn(dev, "Reusing PERST# from Root Complex node. DT needs to be fixed!\n");
}

for_each_available_child_of_node_scoped(dev->of_node, of_port) {
if (!of_node_is_type(of_port, "pci"))
Expand All @@ -1812,7 +1881,9 @@ static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
return ret;

err_port_del:
list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
list_for_each_entry_safe(port, tmp_port, &pcie->ports, list) {
list_for_each_entry_safe(perst, tmp_perst, &port->perst, list)
list_del(&perst->list);
phy_exit(port->phy);
list_del(&port->list);
}
Expand All @@ -1823,6 +1894,7 @@ static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
static int qcom_pcie_parse_legacy_binding(struct qcom_pcie *pcie)
{
struct device *dev = pcie->pci->dev;
struct qcom_pcie_perst *perst;
struct qcom_pcie_port *port;
struct gpio_desc *reset;
struct phy *phy;
Expand All @@ -1844,18 +1916,28 @@ static int qcom_pcie_parse_legacy_binding(struct qcom_pcie *pcie)
if (!port)
return -ENOMEM;

port->reset = reset;
perst = devm_kzalloc(dev, sizeof(*perst), GFP_KERNEL);
if (!perst)
return -ENOMEM;

port->phy = phy;
INIT_LIST_HEAD(&port->list);
list_add_tail(&port->list, &pcie->ports);

perst->desc = reset;
INIT_LIST_HEAD(&port->perst);
INIT_LIST_HEAD(&perst->list);
list_add_tail(&perst->list, &port->perst);

return 0;
}

static int qcom_pcie_probe(struct platform_device *pdev)
{
struct qcom_pcie_perst *perst, *tmp_perst;
struct qcom_pcie_port *port, *tmp_port;
const struct qcom_pcie_cfg *pcie_cfg;
struct qcom_pcie_port *port, *tmp;
unsigned long max_freq = ULONG_MAX;
struct device *dev = &pdev->dev;
struct qcom_pcie *pcie;
struct dw_pcie_rp *pp;
Expand Down Expand Up @@ -1982,7 +2064,7 @@ static int qcom_pcie_probe(struct platform_device *pdev)

ret = qcom_pcie_parse_ports(pcie);
if (ret) {
if (ret != -ENOENT) {
if (ret != -ENODEV) {
dev_err_probe(pci->dev, ret,
"Failed to parse Root Port: %d\n", ret);
goto err_pm_runtime_put;
Expand Down Expand Up @@ -2014,7 +2096,9 @@ static int qcom_pcie_probe(struct platform_device *pdev)
return 0;

err_phy_exit:
list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
list_for_each_entry_safe(port, tmp_port, &pcie->ports, list) {
list_for_each_entry_safe(perst, tmp_perst, &port->perst, list)
list_del(&perst->list);
phy_exit(port->phy);
list_del(&port->list);
}
Expand Down