Commit 6140d185 authored by Bartosz Golaszewski's avatar Bartosz Golaszewski
Browse files

PCI/pwrctl: Add a PCI power control driver for power sequenced devices 



Add a PCI power control driver that's capable of correctly powering up
devices using the power sequencing subsystem. The first users of this
driver are the ath11k module on QCA6390 and ath12k on WCN7850. These
packages require a certain delay between enabling the Bluetooth and WLAN
modules and the power sequencing subsystem takes care of it behind the
scenes.

Tested-by: default avatarAmit Pundir <amit.pundir@linaro.org>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD, SM8650-QRD & SM8650-HDK
Tested-by: Caleb Connolly <caleb.connolly@linaro.org> # OnePlus 8T
Acked-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20240612082019.19161-6-brgl@bgdev.pl


Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
parent 4565d265

drivers/pci/pwrctl/Kconfig

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@@ -5,4 +5,13 @@ 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

drivers/pci/pwrctl/Makefile

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@@ -2,3 +2,5 @@ 


obj-$(CONFIG_PCI_PWRCTL)		+= pci-pwrctl-core.o

pci-pwrctl-core-y			:= core.o



obj-$(CONFIG_PCI_PWRCTL_PWRSEQ)		+= pci-pwrctl-pwrseq.o

drivers/pci/pwrctl/pci-pwrctl-pwrseq.c

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// 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");