[v2,2/4] soc: qcom: pmic_glink: Introduce base PMIC GLINK driver

diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index 21c4ce2315ba..3f2b51905e23 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -100,6 +100,21 @@  config QCOM_PDR_HELPERS
 	tristate
 	select QCOM_QMI_HELPERS
 
+config QCOM_PMIC_GLINK
+	tristate "Qualcomm PMIC GLINK driver"
+	depends on RPMSG
+	depends on TYPEC
+	depends on DRM
+	select AUXILIARY_BUS
+	select QCOM_PDR_HELPERS
+	help
+	  The Qualcomm PMIC GLINK driver provides access, over GLINK, to the
+	  USB and battery firmware running on one of the coprocessors in
+	  several modern Qualcomm platforms.
+
+	  Say yes here to support USB-C and battery status on modern Qualcomm
+	  platforms.
+
 config QCOM_QMI_HELPERS
 	tristate
 	depends on NET
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index 3b92c6c8e0ec..29cccac472f3 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -9,6 +9,7 @@  obj-$(CONFIG_QCOM_GSBI)	+=	qcom_gsbi.o
 obj-$(CONFIG_QCOM_MDT_LOADER)	+= mdt_loader.o
 obj-$(CONFIG_QCOM_OCMEM)	+= ocmem.o
 obj-$(CONFIG_QCOM_PDR_HELPERS)	+= pdr_interface.o
+obj-$(CONFIG_QCOM_PMIC_GLINK)	+= pmic_glink.o
 obj-$(CONFIG_QCOM_QMI_HELPERS)	+= qmi_helpers.o
 qmi_helpers-y	+= qmi_encdec.o qmi_interface.o
 obj-$(CONFIG_QCOM_RAMP_CTRL)	+= ramp_controller.o
diff --git a/drivers/soc/qcom/pmic_glink.c b/drivers/soc/qcom/pmic_glink.c
new file mode 100644
index 000000000000..bb3fb57abcc6
--- /dev/null
+++ b/drivers/soc/qcom/pmic_glink.c
@@ -0,0 +1,336 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2019-2020, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2022, Linaro Ltd
+ */
+#include <linux/auxiliary_bus.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/rpmsg.h>
+#include <linux/slab.h>
+#include <linux/soc/qcom/pdr.h>
+#include <linux/soc/qcom/pmic_glink.h>
+
+struct pmic_glink {
+	struct device *dev;
+	struct pdr_handle *pdr;
+
+	struct rpmsg_endpoint *ept;
+
+	struct auxiliary_device altmode_aux;
+	struct auxiliary_device ps_aux;
+	struct auxiliary_device ucsi_aux;
+
+	/* serializing client_state and pdr_state updates */
+	struct mutex state_lock;
+	unsigned int client_state;
+	unsigned int pdr_state;
+
+	/* serializing clients list updates */
+	struct mutex client_lock;
+	struct list_head clients;
+};
+
+static struct pmic_glink *__pmic_glink;
+static DEFINE_MUTEX(__pmic_glink_lock);
+
+struct pmic_glink_client {
+	struct list_head node;
+
+	struct pmic_glink *pg;
+	unsigned int id;
+
+	void (*cb)(const void *data, size_t len, void *priv);
+	void (*pdr_notify)(void *priv, int state);
+	void *priv;
+};
+
+static void _devm_pmic_glink_release_client(struct device *dev, void *res)
+{
+	struct pmic_glink_client *client = (struct pmic_glink_client *)res;
+	struct pmic_glink *pg = client->pg;
+
+	mutex_lock(&pg->client_lock);
+	list_del(&client->node);
+	mutex_unlock(&pg->client_lock);
+}
+
+struct pmic_glink_client *devm_pmic_glink_register_client(struct device *dev,
+							  unsigned int id,
+							  void (*cb)(const void *, size_t, void *),
+							  void (*pdr)(void *, int),
+							  void *priv)
+{
+	struct pmic_glink_client *client;
+	struct pmic_glink *pg = dev_get_drvdata(dev->parent);
+
+	client = devres_alloc(_devm_pmic_glink_release_client, sizeof(*client), GFP_KERNEL);
+	if (!client)
+		return ERR_PTR(-ENOMEM);
+
+	client->pg = pg;
+	client->id = id;
+	client->cb = cb;
+	client->pdr_notify = pdr;
+	client->priv = priv;
+
+	mutex_lock(&pg->client_lock);
+	list_add(&client->node, &pg->clients);
+	mutex_unlock(&pg->client_lock);
+
+	devres_add(dev, client);
+
+	return client;
+}
+EXPORT_SYMBOL_GPL(devm_pmic_glink_register_client);
+
+int pmic_glink_send(struct pmic_glink_client *client, void *data, size_t len)
+{
+	struct pmic_glink *pg = client->pg;
+
+	return rpmsg_send(pg->ept, data, len);
+}
+EXPORT_SYMBOL_GPL(pmic_glink_send);
+
+static int pmic_glink_rpmsg_callback(struct rpmsg_device *rpdev, void *data,
+				     int len, void *priv, u32 addr)
+{
+	struct pmic_glink_client *client;
+	struct pmic_glink_hdr *hdr;
+	struct pmic_glink *pg = dev_get_drvdata(&rpdev->dev);
+
+	if (len < sizeof(*hdr)) {
+		dev_warn(pg->dev, "ignoring truncated message\n");
+		return 0;
+	}
+
+	hdr = data;
+
+	list_for_each_entry(client, &pg->clients, node) {
+		if (client->id == le32_to_cpu(hdr->owner))
+			client->cb(data, len, client->priv);
+	}
+
+	return 0;
+}
+
+static void pmic_glink_aux_release(struct device *dev) {}
+
+static int pmic_glink_add_aux_device(struct pmic_glink *pg,
+				     struct auxiliary_device *aux,
+				     const char *name)
+{
+	struct device *parent = pg->dev;
+	int ret;
+
+	aux->name = name;
+	aux->dev.parent = parent;
+	aux->dev.release = pmic_glink_aux_release;
+	device_set_of_node_from_dev(&aux->dev, parent);
+	ret = auxiliary_device_init(aux);
+	if (ret)
+		return ret;
+
+	ret = auxiliary_device_add(aux);
+	if (ret)
+		auxiliary_device_uninit(aux);
+
+	return ret;
+}
+
+static void pmic_glink_del_aux_device(struct pmic_glink *pg,
+				      struct auxiliary_device *aux)
+{
+	auxiliary_device_delete(aux);
+	auxiliary_device_uninit(aux);
+}
+
+static void pmic_glink_state_notify_clients(struct pmic_glink *pg)
+{
+	struct pmic_glink_client *client;
+	unsigned int new_state = pg->client_state;
+
+	if (pg->client_state != SERVREG_SERVICE_STATE_UP) {
+		if (pg->pdr_state == SERVREG_SERVICE_STATE_UP && pg->ept)
+			new_state = SERVREG_SERVICE_STATE_UP;
+	} else {
+		if (pg->pdr_state == SERVREG_SERVICE_STATE_UP && pg->ept)
+			new_state = SERVREG_SERVICE_STATE_DOWN;
+	}
+
+	if (new_state != pg->client_state) {
+		list_for_each_entry(client, &pg->clients, node)
+			client->pdr_notify(client->priv, new_state);
+		pg->client_state = new_state;
+	}
+}
+
+static void pmic_glink_pdr_callback(int state, char *svc_path, void *priv)
+{
+	struct pmic_glink *pg = priv;
+
+	mutex_lock(&pg->state_lock);
+	pg->pdr_state = state;
+
+	pmic_glink_state_notify_clients(pg);
+	mutex_unlock(&pg->state_lock);
+}
+
+static int pmic_glink_rpmsg_probe(struct rpmsg_device *rpdev)
+{
+	struct pmic_glink *pg = __pmic_glink;
+	int ret = 0;
+
+	mutex_lock(&__pmic_glink_lock);
+	if (!pg) {
+		ret = dev_err_probe(&rpdev->dev, -ENODEV, "no pmic_glink device to attach to\n");
+		goto out_unlock;
+	}
+
+	dev_set_drvdata(&rpdev->dev, pg);
+
+	mutex_lock(&pg->state_lock);
+	pg->ept = rpdev->ept;
+	pmic_glink_state_notify_clients(pg);
+	mutex_unlock(&pg->state_lock);
+
+out_unlock:
+	mutex_unlock(&__pmic_glink_lock);
+	return ret;
+}
+
+static void pmic_glink_rpmsg_remove(struct rpmsg_device *rpdev)
+{
+	struct pmic_glink *pg;
+
+	mutex_lock(&__pmic_glink_lock);
+	pg = __pmic_glink;
+	if (!pg)
+		goto out_unlock;
+
+	mutex_lock(&pg->state_lock);
+	pg->ept = NULL;
+	pmic_glink_state_notify_clients(pg);
+	mutex_unlock(&pg->state_lock);
+out_unlock:
+	mutex_unlock(&__pmic_glink_lock);
+}
+
+static const struct rpmsg_device_id pmic_glink_rpmsg_id_match[] = {
+	{ "PMIC_RTR_ADSP_APPS" },
+	{}
+};
+
+static struct rpmsg_driver pmic_glink_rpmsg_driver = {
+	.probe = pmic_glink_rpmsg_probe,
+	.remove = pmic_glink_rpmsg_remove,
+	.callback = pmic_glink_rpmsg_callback,
+	.id_table = pmic_glink_rpmsg_id_match,
+	.drv  = {
+		.name  = "qcom_pmic_glink_rpmsg",
+	},
+};
+
+static int pmic_glink_probe(struct platform_device *pdev)
+{
+	struct pdr_service *service;
+	struct pmic_glink *pg;
+	int ret;
+
+	pg = devm_kzalloc(&pdev->dev, sizeof(*pg), GFP_KERNEL);
+	if (!pg)
+		return -ENOMEM;
+
+	dev_set_drvdata(&pdev->dev, pg);
+
+	pg->dev = &pdev->dev;
+
+	INIT_LIST_HEAD(&pg->clients);
+	mutex_init(&pg->client_lock);
+	mutex_init(&pg->state_lock);
+
+	ret = pmic_glink_add_aux_device(pg, &pg->altmode_aux, "altmode");
+	if (ret)
+		return ret;
+	ret = pmic_glink_add_aux_device(pg, &pg->ps_aux, "power-supply");
+	if (ret)
+		goto out_release_altmode_aux;
+
+	pg->pdr = pdr_handle_alloc(pmic_glink_pdr_callback, pg);
+	if (IS_ERR(pg->pdr)) {
+		ret = dev_err_probe(&pdev->dev, PTR_ERR(pg->pdr), "failed to initialize pdr\n");
+		goto out_release_aux_devices;
+	}
+
+	service = pdr_add_lookup(pg->pdr, "tms/servreg", "msm/adsp/charger_pd");
+	if (IS_ERR(service)) {
+		ret = dev_err_probe(&pdev->dev, PTR_ERR(service),
+				    "failed adding pdr lookup for charger_pd\n");
+		goto out_release_pdr_handle;
+	}
+
+	mutex_lock(&__pmic_glink_lock);
+	__pmic_glink = pg;
+	mutex_unlock(&__pmic_glink_lock);
+
+	return 0;
+
+out_release_pdr_handle:
+	pdr_handle_release(pg->pdr);
+out_release_aux_devices:
+	pmic_glink_del_aux_device(pg, &pg->ps_aux);
+out_release_altmode_aux:
+	pmic_glink_del_aux_device(pg, &pg->altmode_aux);
+
+	return ret;
+}
+
+static int pmic_glink_remove(struct platform_device *pdev)
+{
+	struct pmic_glink *pg = dev_get_drvdata(&pdev->dev);
+
+	pdr_handle_release(pg->pdr);
+
+	pmic_glink_del_aux_device(pg, &pg->ps_aux);
+	pmic_glink_del_aux_device(pg, &pg->altmode_aux);
+
+	mutex_lock(&__pmic_glink_lock);
+	__pmic_glink = NULL;
+	mutex_unlock(&__pmic_glink_lock);
+
+	return 0;
+}
+
+static const struct of_device_id pmic_glink_of_match[] = {
+	{ .compatible = "qcom,pmic-glink", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, pmic_glink_of_match);
+
+static struct platform_driver pmic_glink_driver = {
+	.probe = pmic_glink_probe,
+	.remove = pmic_glink_remove,
+	.driver = {
+		.name = "qcom_pmic_glink",
+		.of_match_table = pmic_glink_of_match,
+	},
+};
+
+static int pmic_glink_init(void)
+{
+	platform_driver_register(&pmic_glink_driver);
+	register_rpmsg_driver(&pmic_glink_rpmsg_driver);
+
+	return 0;
+};
+module_init(pmic_glink_init);
+
+static void pmic_glink_exit(void)
+{
+	unregister_rpmsg_driver(&pmic_glink_rpmsg_driver);
+	platform_driver_unregister(&pmic_glink_driver);
+};
+module_exit(pmic_glink_exit);
+
+MODULE_DESCRIPTION("Qualcomm PMIC GLINK driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/soc/qcom/pmic_glink.h b/include/linux/soc/qcom/pmic_glink.h
new file mode 100644
index 000000000000..fd124aa18c81
--- /dev/null
+++ b/include/linux/soc/qcom/pmic_glink.h
@@ -0,0 +1,32 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2022, Linaro Ltd
+ */
+#ifndef __SOC_QCOM_PMIC_GLINK_H__
+#define __SOC_QCOM_PMIC_GLINK_H__
+
+struct pmic_glink;
+struct pmic_glink_client;
+
+#define PMIC_GLINK_OWNER_BATTMGR	32778
+#define PMIC_GLINK_OWNER_USBC		32779
+#define PMIC_GLINK_OWNER_USBC_PAN	32780
+
+#define PMIC_GLINK_REQ_RESP		1
+#define PMIC_GLINK_NOTIFY		2
+
+struct pmic_glink_hdr {
+	__le32 owner;
+	__le32 type;
+	__le32 opcode;
+};
+
+int pmic_glink_send(struct pmic_glink_client *client, void *data, size_t len);
+
+struct pmic_glink_client *devm_pmic_glink_register_client(struct device *dev,
+							  unsigned int id,
+							  void (*cb)(const void *, size_t, void *),
+							  void (*pdr)(void *, int),
+							  void *priv);
+
+#endif