pci-pwrctrl-pwrseq.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2024 Linaro Ltd.
  4 */
  5
  6#include <linux/device.h>
  7#include <linux/mod_devicetable.h>
  8#include <linux/module.h>
  9#include <linux/pci-pwrctrl.h>
 10#include <linux/platform_device.h>
 11#include <linux/property.h>
 12#include <linux/pwrseq/consumer.h>
 13#include <linux/slab.h>
 14#include <linux/types.h>
 15
 16struct pci_pwrctrl_pwrseq_data {
 17	struct pci_pwrctrl ctx;
 18	struct pwrseq_desc *pwrseq;
 19};
 20
 21struct pci_pwrctrl_pwrseq_pdata {
 22	const char *target;
 23	/*
 24	 * Called before doing anything else to perform device-specific
 25	 * verification between requesting the power sequencing handle.
 26	 */
 27	int (*validate_device)(struct device *dev);
 28};
 29
 30static int pci_pwrctrl_pwrseq_qcm_wcn_validate_device(struct device *dev)
 31{
 32	/*
 33	 * Old device trees for some platforms already define wifi nodes for
 34	 * the WCN family of chips since before power sequencing was added
 35	 * upstream.
 36	 *
 37	 * These nodes don't consume the regulator outputs from the PMU, and
 38	 * if we allow this driver to bind to one of such "incomplete" nodes,
 39	 * we'll see a kernel log error about the indefinite probe deferral.
 40	 *
 41	 * Check the existence of the regulator supply that exists on all
 42	 * WCN models before moving forward.
 43	 */
 44	if (!device_property_present(dev, "vddaon-supply"))
 45		return -ENODEV;
 46
 47	return 0;
 48}
 49
 50static const struct pci_pwrctrl_pwrseq_pdata pci_pwrctrl_pwrseq_qcom_wcn_pdata = {
 51	.target = "wlan",
 52	.validate_device = pci_pwrctrl_pwrseq_qcm_wcn_validate_device,
 53};
 54
 55static void devm_pci_pwrctrl_pwrseq_power_off(void *data)
 56{
 57	struct pwrseq_desc *pwrseq = data;
 58
 59	pwrseq_power_off(pwrseq);
 60}
 61
 62static int pci_pwrctrl_pwrseq_probe(struct platform_device *pdev)
 63{
 64	const struct pci_pwrctrl_pwrseq_pdata *pdata;
 65	struct pci_pwrctrl_pwrseq_data *data;
 66	struct device *dev = &pdev->dev;
 67	int ret;
 68
 69	pdata = device_get_match_data(dev);
 70	if (!pdata || !pdata->target)
 71		return -EINVAL;
 72
 73	if (pdata->validate_device) {
 74		ret = pdata->validate_device(dev);
 75		if (ret)
 76			return ret;
 77	}
 78
 79	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 80	if (!data)
 81		return -ENOMEM;
 82
 83	data->pwrseq = devm_pwrseq_get(dev, pdata->target);
 84	if (IS_ERR(data->pwrseq))
 85		return dev_err_probe(dev, PTR_ERR(data->pwrseq),
 86				     "Failed to get the power sequencer\n");
 87
 88	ret = pwrseq_power_on(data->pwrseq);
 89	if (ret)
 90		return dev_err_probe(dev, ret,
 91				     "Failed to power-on the device\n");
 92
 93	ret = devm_add_action_or_reset(dev, devm_pci_pwrctrl_pwrseq_power_off,
 94				       data->pwrseq);
 95	if (ret)
 96		return ret;
 97
 98	pci_pwrctrl_init(&data->ctx, dev);
 99
100	ret = devm_pci_pwrctrl_device_set_ready(dev, &data->ctx);
101	if (ret)
102		return dev_err_probe(dev, ret,
103				     "Failed to register the pwrctrl wrapper\n");
104
105	return 0;
106}
107
108static const struct of_device_id pci_pwrctrl_pwrseq_of_match[] = {
109	{
110		/* ATH11K in QCA6390 package. */
111		.compatible = "pci17cb,1101",
112		.data = &pci_pwrctrl_pwrseq_qcom_wcn_pdata,
113	},
114	{
115		/* ATH11K in WCN6855 package. */
116		.compatible = "pci17cb,1103",
117		.data = &pci_pwrctrl_pwrseq_qcom_wcn_pdata,
118	},
119	{
120		/* ATH12K in WCN7850 package. */
121		.compatible = "pci17cb,1107",
122		.data = &pci_pwrctrl_pwrseq_qcom_wcn_pdata,
123	},
124	{ }
125};
126MODULE_DEVICE_TABLE(of, pci_pwrctrl_pwrseq_of_match);
127
128static struct platform_driver pci_pwrctrl_pwrseq_driver = {
129	.driver = {
130		.name = "pci-pwrctrl-pwrseq",
131		.of_match_table = pci_pwrctrl_pwrseq_of_match,
132	},
133	.probe = pci_pwrctrl_pwrseq_probe,
134};
135module_platform_driver(pci_pwrctrl_pwrseq_driver);
136
137MODULE_AUTHOR("Bartosz Golaszewski <bartosz.golaszewski@linaro.org>");
138MODULE_DESCRIPTION("Generic PCI Power Control module for power sequenced devices");
139MODULE_LICENSE("GPL");