--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Battery Charger Driver for Samsung S2M series PMICs.
+ *
+ * Copyright (c) 2015 Samsung Electronics Co., Ltd
+ * Copyright (c) 2026 Kaustabh Chakraborty <kauschluss@disroot.org>
+ * Copyright (c) 2026 Łukasz Lebiedziński <kernel@lvkasz.us>
+ */
+
+#include <linux/devm-helpers.h>
+#include <linux/extcon.h>
+#include <linux/mfd/samsung/core.h>
+#include <linux/mfd/samsung/s2mu005.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/regmap.h>
+
+struct s2m_chgr {
+ struct device *dev;
+ struct regmap *regmap;
+ struct power_supply *psy;
+ struct extcon_dev *extcon;
+ struct work_struct extcon_work;
+ struct notifier_block extcon_nb;
+};
+
+static int s2mu005_chgr_get_online(struct s2m_chgr *priv, int *value)
+{
+ u32 val;
+ int ret;
+
+ ret = regmap_read(priv->regmap, S2MU005_REG_CHGR_STATUS0, &val);
+ if (ret) {
+ dev_err(priv->dev, "failed to read register (%d)\n", ret);
+ return ret;
+ }
+
+ *value = !!(val & S2MU005_CHGR_CHG);
+
+ return 0;
+}
+
+static void s2mu005_chgr_get_usb_type(struct s2m_chgr *priv, int *value)
+{
+ if (extcon_get_state(priv->extcon, EXTCON_CHG_USB_CDP) > 0)
+ *value = POWER_SUPPLY_USB_TYPE_CDP;
+ else if (extcon_get_state(priv->extcon, EXTCON_CHG_USB_SDP) > 0)
+ *value = POWER_SUPPLY_USB_TYPE_SDP;
+ else if (extcon_get_state(priv->extcon, EXTCON_CHG_USB_DCP) > 0)
+ *value = POWER_SUPPLY_USB_TYPE_DCP;
+ else
+ *value = POWER_SUPPLY_USB_TYPE_UNKNOWN;
+}
+
+static int s2mu005_chgr_get_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct s2m_chgr *priv = power_supply_get_drvdata(psy);
+ int ret;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_ONLINE:
+ ret = s2mu005_chgr_get_online(priv, &val->intval);
+ if (ret)
+ return ret;
+ break;
+ case POWER_SUPPLY_PROP_USB_TYPE:
+ s2mu005_chgr_get_usb_type(priv, &val->intval);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int s2mu005_chgr_mode_set_host(struct s2m_chgr *priv)
+{
+ int ret;
+
+ /* set mode to OTG */
+ ret = regmap_update_bits(priv->regmap, S2MU005_REG_CHGR_CTRL0,
+ S2MU005_CHGR_OP_MODE,
+ FIELD_PREP(S2MU005_CHGR_OP_MODE,
+ S2MU005_CHGR_OP_MODE_OTG));
+ if (ret) {
+ dev_err(priv->dev, "failed to set OTG mode (%d)\n", ret);
+ return ret;
+ }
+
+ /* set boost frequency to 2MHz */
+ ret = regmap_update_bits(priv->regmap, S2MU005_REG_CHGR_CTRL11,
+ S2MU005_CHGR_OSC_BOOST,
+ FIELD_PREP(S2MU005_CHGR_OSC_BOOST,
+ S2MU005_CHGR_OSC_BOOST_2MHZ));
+ if (ret) {
+ dev_err(priv->dev, "failed to set boost frequency (%d)\n", ret);
+ return ret;
+ }
+
+ /* set OTG current limit to 1.5 A */
+ ret = regmap_update_bits(priv->regmap, S2MU005_REG_CHGR_CTRL4,
+ S2MU005_CHGR_OTG_OCP,
+ FIELD_PREP(S2MU005_CHGR_OTG_OCP,
+ S2MU005_CHGR_OTG_OCP_1P5A));
+ if (ret) {
+ dev_err(priv->dev, "failed to set OTG current limit (%d)\n", ret);
+ return ret;
+ }
+
+ /* VBUS switches are OFF when OTG over-current happens */
+ ret = regmap_set_bits(priv->regmap, S2MU005_REG_CHGR_CTRL4,
+ S2MU005_CHGR_OTG_OCP_OFF);
+ if (ret) {
+ dev_err(priv->dev, "failed to set OTG OCP switch (%d)\n", ret);
+ return ret;
+ }
+
+ /* set OTG voltage to 5.1 V */
+ ret = regmap_update_bits(priv->regmap, S2MU005_REG_CHGR_CTRL5,
+ S2MU005_CHGR_VMID_BOOST,
+ FIELD_PREP(S2MU005_CHGR_VMID_BOOST,
+ S2MU005_CHGR_VMID_BOOST_5P1V));
+ if (ret) {
+ dev_err(priv->dev, "failed to set OTG voltage (%d)\n", ret);
+ return ret;
+ }
+
+ /* turn on OTG */
+ ret = regmap_update_bits(priv->regmap, S2MU005_REG_CHGR_CTRL15,
+ S2MU005_CHGR_OTG_EN,
+ FIELD_PREP(S2MU005_CHGR_OTG_EN,
+ S2MU005_CHGR_OTG_EN_ON));
+ if (ret) {
+ dev_err(priv->dev, "failed to turn on OTG (%d)\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int s2mu005_chgr_mode_set_charger(struct s2m_chgr *priv)
+{
+ int ret;
+
+ /* first reset to mode 0 */
+ ret = regmap_clear_bits(priv->regmap, S2MU005_REG_CHGR_CTRL0,
+ S2MU005_CHGR_OP_MODE);
+ if (ret) {
+ dev_err(priv->dev, "failed to reset opmode (%d)\n", ret);
+ return ret;
+ }
+
+ /* wait for the charger to settle before switching to charging mode */
+ msleep(50);
+ /* then set to charging mode */
+ ret = regmap_update_bits(priv->regmap, S2MU005_REG_CHGR_CTRL0,
+ S2MU005_CHGR_OP_MODE,
+ FIELD_PREP(S2MU005_CHGR_OP_MODE,
+ S2MU005_CHGR_OP_MODE_CHG));
+ if (ret) {
+ dev_err(priv->dev, "failed to set opmode to charging (%d)\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int s2mu005_chgr_mode_unset(struct s2m_chgr *priv)
+{
+ int ret;
+
+ /* turn off OTG */
+ ret = regmap_clear_bits(priv->regmap, S2MU005_REG_CHGR_CTRL15,
+ S2MU005_CHGR_OTG_EN);
+ if (ret) {
+ dev_err(priv->dev, "failed to turn off OTG (%d)\n", ret);
+ return ret;
+ }
+
+ /* reset operation mode */
+ ret = regmap_clear_bits(priv->regmap, S2MU005_REG_CHGR_CTRL0,
+ S2MU005_CHGR_OP_MODE);
+ if (ret) {
+ dev_err(priv->dev, "failed to reset opmode (%d)\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void s2mu005_chgr_extcon_work(struct work_struct *work)
+{
+ struct s2m_chgr *priv = container_of(work, struct s2m_chgr, extcon_work);
+
+ if (extcon_get_state(priv->extcon, EXTCON_USB_HOST) > 0)
+ s2mu005_chgr_mode_set_host(priv);
+ else if (extcon_get_state(priv->extcon, EXTCON_USB) > 0)
+ s2mu005_chgr_mode_set_charger(priv);
+ else
+ s2mu005_chgr_mode_unset(priv);
+
+ power_supply_changed(priv->psy);
+}
+
+static const enum power_supply_property s2mu005_chgr_properties[] = {
+ POWER_SUPPLY_PROP_ONLINE,
+ POWER_SUPPLY_PROP_USB_TYPE,
+};
+
+static const struct power_supply_desc s2mu005_chgr_psy_desc = {
+ .name = "s2mu005-charger",
+ .type = POWER_SUPPLY_TYPE_USB,
+ .properties = s2mu005_chgr_properties,
+ .num_properties = ARRAY_SIZE(s2mu005_chgr_properties),
+ .get_property = s2mu005_chgr_get_property,
+ .usb_types = BIT(POWER_SUPPLY_USB_TYPE_CDP) |
+ BIT(POWER_SUPPLY_USB_TYPE_SDP) |
+ BIT(POWER_SUPPLY_USB_TYPE_DCP) |
+ BIT(POWER_SUPPLY_USB_TYPE_UNKNOWN),
+};
+
+static int s2m_chgr_extcon_notifier(struct notifier_block *nb,
+ unsigned long event, void *param)
+{
+ struct s2m_chgr *priv = container_of(nb, struct s2m_chgr, extcon_nb);
+
+ schedule_work(&priv->extcon_work);
+
+ return NOTIFY_OK;
+}
+
+static int s2m_chgr_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct sec_pmic_dev *pmic_drvdata = dev_get_drvdata(dev->parent);
+ struct s2m_chgr *priv;
+ struct device_node *extcon_node __free(device_node) = NULL;
+ struct power_supply_config psy_cfg = {};
+ const struct power_supply_desc *psy_desc;
+ work_func_t extcon_work_func;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, priv);
+ priv->dev = dev;
+ priv->regmap = pmic_drvdata->regmap_pmic;
+
+ switch (platform_get_device_id(pdev)->driver_data) {
+ case S2MU005:
+ psy_desc = &s2mu005_chgr_psy_desc;
+ extcon_work_func = s2mu005_chgr_extcon_work;
+ break;
+ default:
+ return dev_err_probe(dev, -ENODEV,
+ "device type %d is not supported by driver\n",
+ pmic_drvdata->device_type);
+ }
+
+ /* MUIC is mandatory. If unavailable, request probe deferral */
+ extcon_node = of_get_child_by_name(dev->parent->of_node, "muic");
+ if (!extcon_node)
+ return dev_err_probe(dev, -ENODEV, "MUIC node required but not found\n");
+
+ priv->extcon = extcon_find_edev_by_node(extcon_node);
+ if (IS_ERR(priv->extcon))
+ return -EPROBE_DEFER;
+
+ psy_cfg.drv_data = priv;
+ psy_cfg.fwnode = dev_fwnode(dev->parent);
+ priv->psy = devm_power_supply_register(dev, psy_desc, &psy_cfg);
+ if (IS_ERR(priv->psy))
+ return dev_err_probe(dev, PTR_ERR(priv->psy),
+ "failed to register power supply subsystem\n");
+
+ ret = devm_work_autocancel(dev, &priv->extcon_work, extcon_work_func);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to initialize extcon work\n");
+
+ priv->extcon_nb.notifier_call = s2m_chgr_extcon_notifier;
+ ret = devm_extcon_register_notifier_all(dev, priv->extcon, &priv->extcon_nb);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to register extcon notifier\n");
+
+ return 0;
+}
+
+static const struct platform_device_id s2m_chgr_id_table[] = {
+ { "s2mu005-charger", S2MU005 },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(platform, s2m_chgr_id_table);
+
+static struct platform_driver s2m_chgr_driver = {
+ .driver = {
+ .name = "s2m-charger",
+ },
+ .probe = s2m_chgr_probe,
+ .id_table = s2m_chgr_id_table,
+};
+module_platform_driver(s2m_chgr_driver);
+
+MODULE_DESCRIPTION("Battery Charger Driver For Samsung S2M Series PMICs");
+MODULE_AUTHOR("Kaustabh Chakraborty <kauschluss@disroot.org>");
+MODULE_AUTHOR("Łukasz Lebiedziński <kernel@lvkasz.us>");
+MODULE_LICENSE("GPL");