Commit b921aa3f authored by Manivannan Sadhasivam's avatar Manivannan Sadhasivam Committed by Bjorn Helgaas
Browse files

PCI/pwrctrl: Switch to pwrctrl create, power on/off, destroy APIs 



Adopt pwrctrl APIs to create, power on/off, and destroy pwrctrl devices.

In qcom_pcie_host_init(), call pci_pwrctrl_create_devices() to create
devices, then pci_pwrctrl_power_on_devices() to power them on, both after
controller resource initialization. Once successful, deassert PERST# for
all devices.

In qcom_pcie_host_deinit(), call pci_pwrctrl_power_off_devices() after
asserting PERST#. Note that pci_pwrctrl_destroy_devices() is not called
here, as deinit is only invoked during system suspend where device
destruction is unnecessary. If the driver becomes removable in future,
pci_pwrctrl_destroy_devices() should be called in the remove() handler.

Remove the old pwrctrl framework code from the PCI core (including
devlinks) as the new APIs are now the sole consumer of pwrctrl
functionality. And also do not power on the pwrctrl drivers during probe()
as this is now handled by the APIs.

Co-developed-by: default avatarKrishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
Signed-off-by: default avatarKrishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
Signed-off-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Tested-by: default avatarChen-Yu Tsai <wenst@chromium.org>
Reviewed-by: default avatarBartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260115-pci-pwrctrl-rework-v5-12-9d26da3ce903@oss.qualcomm.com
parent b35cf3b6

drivers/pci/bus.c

+0 −19
Original line number Diff line number Diff line
@@ -344,7 +344,6 @@ void __weak pcibios_bus_add_device(struct pci_dev *pdev) { } 
void pci_bus_add_device(struct pci_dev *dev)

{

	struct device_node *dn = dev->dev.of_node;

	struct platform_device *pdev;



	/*

	 * Can not put in pci_device_add yet because resources
@@ -361,24 +360,6 @@ void pci_bus_add_device(struct pci_dev *dev) 
	/* Save config space for error recoverability */

	pci_save_state(dev);



	/*

	 * If the PCI device is associated with a pwrctrl device with a

	 * power supply, create a device link between the PCI device and

	 * pwrctrl device.  This ensures that pwrctrl drivers are probed

	 * before PCI client drivers.

	 */

	pdev = of_find_device_by_node(dn);

	if (pdev) {

		if (of_pci_supply_present(dn)) {

			if (!device_link_add(&dev->dev, &pdev->dev,

					     DL_FLAG_AUTOREMOVE_CONSUMER)) {

				pci_err(dev, "failed to add device link to power control device %s\n",

					pdev->name);

			}

		}

		put_device(&pdev->dev);

	}



	if (!dn || of_device_is_available(dn))

		pci_dev_allow_binding(dev);

drivers/pci/controller/dwc/pcie-qcom.c

+22 −2
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <linux/of_pci.h>

#include <linux/pci.h>

#include <linux/pci-ecam.h>

#include <linux/pci-pwrctrl.h>

#include <linux/pm_opp.h>

#include <linux/pm_runtime.h>

#include <linux/platform_device.h>
@@ -1310,10 +1311,18 @@ static int qcom_pcie_host_init(struct dw_pcie_rp *pp) 
	if (ret)

		goto err_deinit;



	ret = pci_pwrctrl_create_devices(pci->dev);

	if (ret)

		goto err_disable_phy;



	ret = pci_pwrctrl_power_on_devices(pci->dev);

	if (ret)

		goto err_pwrctrl_destroy;



	if (pcie->cfg->ops->post_init) {

		ret = pcie->cfg->ops->post_init(pcie);

		if (ret)

			goto err_disable_phy;

			goto err_pwrctrl_power_off;

	}



	qcom_ep_reset_deassert(pcie);
@@ -1328,6 +1337,11 @@ static int qcom_pcie_host_init(struct dw_pcie_rp *pp) 


err_assert_reset:

	qcom_ep_reset_assert(pcie);

err_pwrctrl_power_off:

	pci_pwrctrl_power_off_devices(pci->dev);

err_pwrctrl_destroy:

	if (ret != -EPROBE_DEFER)

		pci_pwrctrl_destroy_devices(pci->dev);

err_disable_phy:

	qcom_pcie_phy_power_off(pcie);

err_deinit:
@@ -1342,6 +1356,12 @@ static void qcom_pcie_host_deinit(struct dw_pcie_rp *pp) 
	struct qcom_pcie *pcie = to_qcom_pcie(pci);



	qcom_ep_reset_assert(pcie);



	/*

	 * No need to destroy pwrctrl devices as this function only gets called

	 * during system suspend as of now.

	 */

	pci_pwrctrl_power_off_devices(pci->dev);

	qcom_pcie_phy_power_off(pcie);

	pcie->cfg->ops->deinit(pcie);

}
@@ -1961,7 +1981,7 @@ static int qcom_pcie_probe(struct platform_device *pdev) 


	ret = dw_pcie_host_init(pp);

	if (ret) {

		dev_err(dev, "cannot initialize host\n");

		dev_err_probe(dev, ret, "cannot initialize host\n");

		goto err_phy_exit;

	}

drivers/pci/probe.c

+0 −59
Original line number Diff line number Diff line
@@ -2563,56 +2563,6 @@ bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, 
}

EXPORT_SYMBOL(pci_bus_read_dev_vendor_id);



#if IS_ENABLED(CONFIG_PCI_PWRCTRL)

static struct platform_device *pci_pwrctrl_create_device(struct pci_bus *bus, int devfn)

{

	struct pci_host_bridge *host = pci_find_host_bridge(bus);

	struct platform_device *pdev;

	struct device_node *np;



	np = of_pci_find_child_device(dev_of_node(&bus->dev), devfn);

	if (!np)

		return NULL;



	pdev = of_find_device_by_node(np);

	if (pdev) {

		put_device(&pdev->dev);

		goto err_put_of_node;

	}



	/*

	 * First check whether the pwrctrl device really needs to be created or

	 * not. This is decided based on at least one of the power supplies

	 * being defined in the devicetree node of the device.

	 */

	if (!of_pci_supply_present(np)) {

		pr_debug("PCI/pwrctrl: Skipping OF node: %s\n", np->name);

		goto err_put_of_node;

	}



	/* Now create the pwrctrl device */

	pdev = of_platform_device_create(np, NULL, &host->dev);

	if (!pdev) {

		pr_err("PCI/pwrctrl: Failed to create pwrctrl device for node: %s\n", np->name);

		goto err_put_of_node;

	}



	of_node_put(np);



	return pdev;



err_put_of_node:

	of_node_put(np);



	return NULL;

}

#else

static struct platform_device *pci_pwrctrl_create_device(struct pci_bus *bus, int devfn)

{

	return NULL;

}

#endif



/*

 * Read the config data for a PCI device, sanity-check it,

 * and fill in the dev structure.
@@ -2622,15 +2572,6 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn) 
	struct pci_dev *dev;

	u32 l;



	/*

	 * Create pwrctrl device (if required) for the PCI device to handle the

	 * power state. If the pwrctrl device is created, then skip scanning

	 * further as the pwrctrl core will rescan the bus after powering on

	 * the device.

	 */

	if (pci_pwrctrl_create_device(bus, devfn))

		return NULL;



	if (!pci_bus_read_dev_vendor_id(bus, devfn, &l, 60*1000))

		return NULL;

drivers/pci/pwrctrl/core.c

+0 −15
Original line number Diff line number Diff line
@@ -45,16 +45,6 @@ static int pci_pwrctrl_notify(struct notifier_block *nb, unsigned long action, 
	return NOTIFY_DONE;

}



static void rescan_work_func(struct work_struct *work)

{

	struct pci_pwrctrl *pwrctrl = container_of(work,

						   struct pci_pwrctrl, work);



	pci_lock_rescan_remove();

	pci_rescan_bus(to_pci_host_bridge(pwrctrl->dev->parent)->bus);

	pci_unlock_rescan_remove();

}



/**

 * pci_pwrctrl_init() - Initialize the PCI power control context struct

 *
@@ -64,7 +54,6 @@ static void rescan_work_func(struct work_struct *work) 
void pci_pwrctrl_init(struct pci_pwrctrl *pwrctrl, struct device *dev)

{

	pwrctrl->dev = dev;

	INIT_WORK(&pwrctrl->work, rescan_work_func);

	dev_set_drvdata(dev, pwrctrl);

}

EXPORT_SYMBOL_GPL(pci_pwrctrl_init);
@@ -95,8 +84,6 @@ int pci_pwrctrl_device_set_ready(struct pci_pwrctrl *pwrctrl) 
	if (ret)

		return ret;



	schedule_work(&pwrctrl->work);



	return 0;

}

EXPORT_SYMBOL_GPL(pci_pwrctrl_device_set_ready);
@@ -109,8 +96,6 @@ EXPORT_SYMBOL_GPL(pci_pwrctrl_device_set_ready); 
 */

void pci_pwrctrl_device_unset_ready(struct pci_pwrctrl *pwrctrl)

{

	cancel_work_sync(&pwrctrl->work);



	/*

	 * We don't have to delete the link here. Typically, this function

	 * is only called when the power control device is being detached. If

drivers/pci/pwrctrl/pci-pwrctrl-pwrseq.c

+0 −5
Original line number Diff line number Diff line
@@ -101,11 +101,6 @@ static int pwrseq_pwrctrl_probe(struct platform_device *pdev) 
		return dev_err_probe(dev, PTR_ERR(pwrseq->pwrseq),

				     "Failed to get the power sequencer\n");



	ret = pwrseq_pwrctrl_power_on(&pwrseq->pwrctrl);

	if (ret)

		return dev_err_probe(dev, ret,

				     "Failed to power-on the device\n");



	ret = devm_add_action_or_reset(dev, devm_pwrseq_pwrctrl_power_off,

				       pwrseq);

	if (ret)