diff options
Diffstat (limited to 'drivers/pci/pwrctl')
| -rw-r--r-- | drivers/pci/pwrctl/Kconfig | 17 | ||||
| -rw-r--r-- | drivers/pci/pwrctl/Makefile | 6 | ||||
| -rw-r--r-- | drivers/pci/pwrctl/core.c | 137 | ||||
| -rw-r--r-- | drivers/pci/pwrctl/pci-pwrctl-pwrseq.c | 89 |
4 files changed, 249 insertions, 0 deletions
diff --git a/drivers/pci/pwrctl/Kconfig b/drivers/pci/pwrctl/Kconfig new file mode 100644 index 000000000000..f1b824955d4b --- /dev/null +++ b/drivers/pci/pwrctl/Kconfig @@ -0,0 +1,17 @@ +# SPDX-License-Identifier: GPL-2.0-only + +menu "PCI Power control drivers" + +config PCI_PWRCTL + tristate + +config PCI_PWRCTL_PWRSEQ + tristate "PCI Power Control driver using the Power Sequencing subsystem" + select POWER_SEQUENCING + select PCI_PWRCTL + default m if ((ATH11K_PCI || ATH12K) && ARCH_QCOM) + help + Enable support for the PCI power control driver for device + drivers using the Power Sequencing subsystem. + +endmenu diff --git a/drivers/pci/pwrctl/Makefile b/drivers/pci/pwrctl/Makefile new file mode 100644 index 000000000000..d308aae4800c --- /dev/null +++ b/drivers/pci/pwrctl/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0-only + +obj-$(CONFIG_PCI_PWRCTL) += pci-pwrctl-core.o +pci-pwrctl-core-y := core.o + +obj-$(CONFIG_PCI_PWRCTL_PWRSEQ) += pci-pwrctl-pwrseq.o diff --git a/drivers/pci/pwrctl/core.c b/drivers/pci/pwrctl/core.c new file mode 100644 index 000000000000..feca26ad2f6a --- /dev/null +++ b/drivers/pci/pwrctl/core.c @@ -0,0 +1,137 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2024 Linaro Ltd. + */ + +#include <linux/device.h> +#include <linux/export.h> +#include <linux/kernel.h> +#include <linux/pci.h> +#include <linux/pci-pwrctl.h> +#include <linux/property.h> +#include <linux/slab.h> + +static int pci_pwrctl_notify(struct notifier_block *nb, unsigned long action, + void *data) +{ + struct pci_pwrctl *pwrctl = container_of(nb, struct pci_pwrctl, nb); + struct device *dev = data; + + if (dev_fwnode(dev) != dev_fwnode(pwrctl->dev)) + return NOTIFY_DONE; + + switch (action) { + case BUS_NOTIFY_ADD_DEVICE: + /* + * We will have two struct device objects bound to two different + * drivers on different buses but consuming the same DT node. We + * must not bind the pins twice in this case but only once for + * the first device to be added. + * + * If we got here then the PCI device is the second after the + * power control platform device. Mark its OF node as reused. + */ + dev->of_node_reused = true; + break; + case BUS_NOTIFY_BOUND_DRIVER: + pwrctl->link = device_link_add(dev, pwrctl->dev, + DL_FLAG_AUTOREMOVE_CONSUMER); + if (!pwrctl->link) + dev_err(pwrctl->dev, "Failed to add device link\n"); + break; + case BUS_NOTIFY_UNBOUND_DRIVER: + if (pwrctl->link) + device_link_remove(dev, pwrctl->dev); + break; + } + + return NOTIFY_DONE; +} + +/** + * pci_pwrctl_device_set_ready() - Notify the pwrctl subsystem that the PCI + * device is powered-up and ready to be detected. + * + * @pwrctl: PCI power control data. + * + * Returns: + * 0 on success, negative error number on error. + * + * Note: + * This function returning 0 doesn't mean the device was detected. It means, + * that the bus rescan was successfully started. The device will get bound to + * its PCI driver asynchronously. + */ +int pci_pwrctl_device_set_ready(struct pci_pwrctl *pwrctl) +{ + int ret; + + if (!pwrctl->dev) + return -ENODEV; + + pwrctl->nb.notifier_call = pci_pwrctl_notify; + ret = bus_register_notifier(&pci_bus_type, &pwrctl->nb); + if (ret) + return ret; + + pci_lock_rescan_remove(); + pci_rescan_bus(to_pci_dev(pwrctl->dev->parent)->bus); + pci_unlock_rescan_remove(); + + return 0; +} +EXPORT_SYMBOL_GPL(pci_pwrctl_device_set_ready); + +/** + * pci_pwrctl_device_unset_ready() - Notify the pwrctl subsystem that the PCI + * device is about to be powered-down. + * + * @pwrctl: PCI power control data. + */ +void pci_pwrctl_device_unset_ready(struct pci_pwrctl *pwrctl) +{ + /* + * We don't have to delete the link here. Typically, this function + * is only called when the power control device is being detached. If + * it is being detached then the child PCI device must have already + * been unbound too or the device core wouldn't let us unbind. + */ + bus_unregister_notifier(&pci_bus_type, &pwrctl->nb); +} +EXPORT_SYMBOL_GPL(pci_pwrctl_device_unset_ready); + +static void devm_pci_pwrctl_device_unset_ready(void *data) +{ + struct pci_pwrctl *pwrctl = data; + + pci_pwrctl_device_unset_ready(pwrctl); +} + +/** + * devm_pci_pwrctl_device_set_ready - Managed variant of + * pci_pwrctl_device_set_ready(). + * + * @dev: Device managing this pwrctl provider. + * @pwrctl: PCI power control data. + * + * Returns: + * 0 on success, negative error number on error. + */ +int devm_pci_pwrctl_device_set_ready(struct device *dev, + struct pci_pwrctl *pwrctl) +{ + int ret; + + ret = pci_pwrctl_device_set_ready(pwrctl); + if (ret) + return ret; + + return devm_add_action_or_reset(dev, + devm_pci_pwrctl_device_unset_ready, + pwrctl); +} +EXPORT_SYMBOL_GPL(devm_pci_pwrctl_device_set_ready); + +MODULE_AUTHOR("Bartosz Golaszewski <bartosz.golaszewski@linaro.org>"); +MODULE_DESCRIPTION("PCI Device Power Control core driver"); +MODULE_LICENSE("GPL"); diff --git a/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c b/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c new file mode 100644 index 000000000000..c7a113a76c0c --- /dev/null +++ b/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2024 Linaro Ltd. + */ + +#include <linux/device.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/pci-pwrctl.h> +#include <linux/platform_device.h> +#include <linux/pwrseq/consumer.h> +#include <linux/slab.h> +#include <linux/types.h> + +struct pci_pwrctl_pwrseq_data { + struct pci_pwrctl ctx; + struct pwrseq_desc *pwrseq; +}; + +static void devm_pci_pwrctl_pwrseq_power_off(void *data) +{ + struct pwrseq_desc *pwrseq = data; + + pwrseq_power_off(pwrseq); +} + +static int pci_pwrctl_pwrseq_probe(struct platform_device *pdev) +{ + struct pci_pwrctl_pwrseq_data *data; + struct device *dev = &pdev->dev; + int ret; + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->pwrseq = devm_pwrseq_get(dev, of_device_get_match_data(dev)); + if (IS_ERR(data->pwrseq)) + return dev_err_probe(dev, PTR_ERR(data->pwrseq), + "Failed to get the power sequencer\n"); + + ret = pwrseq_power_on(data->pwrseq); + if (ret) + return dev_err_probe(dev, ret, + "Failed to power-on the device\n"); + + ret = devm_add_action_or_reset(dev, devm_pci_pwrctl_pwrseq_power_off, + data->pwrseq); + if (ret) + return ret; + + data->ctx.dev = dev; + + ret = devm_pci_pwrctl_device_set_ready(dev, &data->ctx); + if (ret) + return dev_err_probe(dev, ret, + "Failed to register the pwrctl wrapper\n"); + + return 0; +} + +static const struct of_device_id pci_pwrctl_pwrseq_of_match[] = { + { + /* ATH11K in QCA6390 package. */ + .compatible = "pci17cb,1101", + .data = "wlan", + }, + { + /* ATH12K in WCN7850 package. */ + .compatible = "pci17cb,1107", + .data = "wlan", + }, + { } +}; +MODULE_DEVICE_TABLE(of, pci_pwrctl_pwrseq_of_match); + +static struct platform_driver pci_pwrctl_pwrseq_driver = { + .driver = { + .name = "pci-pwrctl-pwrseq", + .of_match_table = pci_pwrctl_pwrseq_of_match, + }, + .probe = pci_pwrctl_pwrseq_probe, +}; +module_platform_driver(pci_pwrctl_pwrseq_driver); + +MODULE_AUTHOR("Bartosz Golaszewski <bartosz.golaszewski@linaro.org>"); +MODULE_DESCRIPTION("Generic PCI Power Control module for power sequenced devices"); +MODULE_LICENSE("GPL"); |