1 files changed, 139 insertions, 0 deletions
diff --git a/drivers/pci/pwrctrl/pci-pwrctrl-pwrseq.c b/drivers/pci/pwrctrl/pci-pwrctrl-pwrseq.c
new file mode 100644
index 000000000000..4e664e7b8dd2
--- /dev/null
+++ b/drivers/pci/pwrctrl/pci-pwrctrl-pwrseq.c
@@ -0,0 +1,139 @@
+// 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/pci-pwrctrl.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/pwrseq/consumer.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+struct pci_pwrctrl_pwrseq_data {
+	struct pci_pwrctrl ctx;
+	struct pwrseq_desc *pwrseq;
+};
+
+struct pci_pwrctrl_pwrseq_pdata {
+	const char *target;
+	/*
+	 * Called before doing anything else to perform device-specific
+	 * verification between requesting the power sequencing handle.
+	 */
+	int (*validate_device)(struct device *dev);
+};
+
+static int pci_pwrctrl_pwrseq_qcm_wcn_validate_device(struct device *dev)
+{
+	/*
+	 * Old device trees for some platforms already define wifi nodes for
+	 * the WCN family of chips since before power sequencing was added
+	 * upstream.
+	 *
+	 * These nodes don't consume the regulator outputs from the PMU, and
+	 * if we allow this driver to bind to one of such "incomplete" nodes,
+	 * we'll see a kernel log error about the indefinite probe deferral.
+	 *
+	 * Check the existence of the regulator supply that exists on all
+	 * WCN models before moving forward.
+	 */
+	if (!device_property_present(dev, "vddaon-supply"))
+		return -ENODEV;
+
+	return 0;
+}
+
+static const struct pci_pwrctrl_pwrseq_pdata pci_pwrctrl_pwrseq_qcom_wcn_pdata = {
+	.target = "wlan",
+	.validate_device = pci_pwrctrl_pwrseq_qcm_wcn_validate_device,
+};
+
+static void devm_pci_pwrctrl_pwrseq_power_off(void *data)
+{
+	struct pwrseq_desc *pwrseq = data;
+
+	pwrseq_power_off(pwrseq);
+}
+
+static int pci_pwrctrl_pwrseq_probe(struct platform_device *pdev)
+{
+	const struct pci_pwrctrl_pwrseq_pdata *pdata;
+	struct pci_pwrctrl_pwrseq_data *data;
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	pdata = device_get_match_data(dev);
+	if (!pdata || !pdata->target)
+		return -EINVAL;
+
+	if (pdata->validate_device) {
+		ret = pdata->validate_device(dev);
+		if (ret)
+			return ret;
+	}
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->pwrseq = devm_pwrseq_get(dev, pdata->target);
+	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_pwrctrl_pwrseq_power_off,
+				       data->pwrseq);
+	if (ret)
+		return ret;
+
+	pci_pwrctrl_init(&data->ctx, dev);
+
+	ret = devm_pci_pwrctrl_device_set_ready(dev, &data->ctx);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Failed to register the pwrctrl wrapper\n");
+
+	return 0;
+}
+
+static const struct of_device_id pci_pwrctrl_pwrseq_of_match[] = {
+	{
+		/* ATH11K in QCA6390 package. */
+		.compatible = "pci17cb,1101",
+		.data = &pci_pwrctrl_pwrseq_qcom_wcn_pdata,
+	},
+	{
+		/* ATH11K in WCN6855 package. */
+		.compatible = "pci17cb,1103",
+		.data = &pci_pwrctrl_pwrseq_qcom_wcn_pdata,
+	},
+	{
+		/* ATH12K in WCN7850 package. */
+		.compatible = "pci17cb,1107",
+		.data = &pci_pwrctrl_pwrseq_qcom_wcn_pdata,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, pci_pwrctrl_pwrseq_of_match);
+
+static struct platform_driver pci_pwrctrl_pwrseq_driver = {
+	.driver = {
+		.name = "pci-pwrctrl-pwrseq",
+		.of_match_table = pci_pwrctrl_pwrseq_of_match,
+	},
+	.probe = pci_pwrctrl_pwrseq_probe,
+};
+module_platform_driver(pci_pwrctrl_pwrseq_driver);
+
+MODULE_AUTHOR("Bartosz Golaszewski <bartosz.golaszewski@linaro.org>");
+MODULE_DESCRIPTION("Generic PCI Power Control module for power sequenced devices");
+MODULE_LICENSE("GPL");