[PATCH v3 0/2] extcon: add basic Maxim MAX14526 MUIC support

[PATCH v3 0/2] extcon: add basic Maxim MAX14526 MUIC support

[Svyatoslav Ryhel]

The MAX14526 is a simple multiplexer of common inputs on a single
mini/micro USB for portable devices.

---
Changes on switching from v2 to v3:
- fixed overflow issue with ~USB_DET_DIS

Changes on switching from v1 to v2:
- added port and connector to schema
- removed -muic suffix
- removed unneded comment header
- removed unneded gpios in private data
- improved code formatting
---

Svyatoslav Ryhel (2):
  dt-bindings: extcon: Document Maxim MAX14526 MUIC
  extcon: Add basic support for Maxim MAX14526 MUIC

 .../bindings/extcon/maxim,max14526.yaml       |  80 +++++
 drivers/extcon/Kconfig                        |  12 +
 drivers/extcon/Makefile                       |   1 +
 drivers/extcon/extcon-max14526.c              | 302 ++++++++++++++++++
 4 files changed, 395 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/extcon/maxim,max14526.yaml
 create mode 100644 drivers/extcon/extcon-max14526.c

-- 
2.48.1

[PATCH v3 1/2] dt-bindings: extcon: Document Maxim MAX14526 MUIC

[Svyatoslav Ryhel]

Add bindings for Maxim MAX14526 MicroUSB Integrated Circuit.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 .../bindings/extcon/maxim,max14526.yaml       | 80 +++++++++++++++++++
 1 file changed, 80 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/extcon/maxim,max14526.yaml

diff --git a/Documentation/devicetree/bindings/extcon/maxim,max14526.yaml b/Documentation/devicetree/bindings/extcon/maxim,max14526.yaml
new file mode 100644
index 000000000000..7eb5918df1c2
--- /dev/null
+++ b/Documentation/devicetree/bindings/extcon/maxim,max14526.yaml
@@ -0,0 +1,80 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/extcon/maxim,max14526.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Maxim MAX14526 MicroUSB Integrated Circuit (MUIC)
+
+maintainers:
+  - Svyatoslav Ryhel <clamor95@gmail.com>
+
+properties:
+  compatible:
+    const: maxim,max14526
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  connector:
+    $ref: /schemas/connector/usb-connector.yaml#
+
+  port:
+    $ref: /schemas/graph.yaml#/properties/port
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - connector
+  - port
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        muic@44 {
+            compatible = "maxim,max14526";
+            reg = <0x44>;
+
+            interrupt-parent = <&gpio>;
+            interrupts = <72 IRQ_TYPE_EDGE_FALLING>;
+
+            connector {
+                compatible = "usb-b-connector";
+                label = "micro-USB";
+                type = "micro";
+            };
+
+            port {
+                #address-cells = <1>;
+                #size-cells = <0>;
+
+                muic_to_charger: endpoint@0 {
+                    reg = <0>;
+                    remote-endpoint = <&charger_input>;
+                };
+
+                muic_to_usb: endpoint@1 {
+                    reg = <1>;
+                    remote-endpoint = <&usb_input>;
+                };
+
+                muic_to_mhl: endpoint@2 {
+                    reg = <2>;
+                    remote-endpoint = <&mhl_input>;
+                };
+            };
+        };
+    };
+...
-- 
2.48.1

[PATCH v3 2/2] extcon: Add basic support for Maxim MAX14526 MUIC

[Svyatoslav Ryhel]

The MAX14526 is designed to simplify interface requirements on portable
devices by multiplexing common inputs (USB, UART, Microphone, Stereo Audio
and Composite Video) on a single micro/mini USB connector. The USB input
supports Hi-Speed USB and the audio/video inputs feature negative rail
signal operation allowing simple DC coupled accessories. These device allow
a single micro/mini USB port to support all the common interfaces on
Cellular phones and portable media players over the same external lines.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
---
 drivers/extcon/Kconfig           |  12 ++
 drivers/extcon/Makefile          |   1 +
 drivers/extcon/extcon-max14526.c | 302 +++++++++++++++++++++++++++++++
 3 files changed, 315 insertions(+)
 create mode 100644 drivers/extcon/extcon-max14526.c

diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
index a6f6d467aacf..1096afc0b5bb 100644
--- a/drivers/extcon/Kconfig
+++ b/drivers/extcon/Kconfig
@@ -134,6 +134,18 @@ config EXTCON_MAX8997
 	  Maxim MAX8997 PMIC. The MAX8997 MUIC is a USB port accessory
 	  detector and switch.
 
+config EXTCON_MAX14526
+	tristate "Maxim MAX14526 EXTCON Support"
+	select IRQ_DOMAIN
+	select REGMAP_I2C
+	help
+	  If you say yes here you get support for the Maxim MAX14526
+	  MUIC device. The MAX14526 MUIC is a USB port accessory
+	  detector and switch. The MAX14526 is designed to simplify
+	  interface requirements on portable devices by multiplexing
+	  common inputs (USB, UART, Microphone, Stereo Audio and
+	  Composite Video) on a single micro/mini USB connector.
+
 config EXTCON_PALMAS
 	tristate "Palmas USB EXTCON support"
 	depends on MFD_PALMAS
diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
index 0d6d23faf748..6482f2bfd661 100644
--- a/drivers/extcon/Makefile
+++ b/drivers/extcon/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_EXTCON_MAX3355)	+= extcon-max3355.o
 obj-$(CONFIG_EXTCON_MAX77693)	+= extcon-max77693.o
 obj-$(CONFIG_EXTCON_MAX77843)	+= extcon-max77843.o
 obj-$(CONFIG_EXTCON_MAX8997)	+= extcon-max8997.o
+obj-$(CONFIG_EXTCON_MAX14526)	+= extcon-max14526.o
 obj-$(CONFIG_EXTCON_PALMAS)	+= extcon-palmas.o
 obj-$(CONFIG_EXTCON_PTN5150)	+= extcon-ptn5150.o
 obj-$(CONFIG_EXTCON_QCOM_SPMI_MISC) += extcon-qcom-spmi-misc.o
diff --git a/drivers/extcon/extcon-max14526.c b/drivers/extcon/extcon-max14526.c
new file mode 100644
index 000000000000..f9e8ade56d45
--- /dev/null
+++ b/drivers/extcon/extcon-max14526.c
@@ -0,0 +1,302 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/device.h>
+#include <linux/devm-helpers.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/extcon-provider.h>
+#include <linux/i2c.h>
+#include <linux/mod_devicetable.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/regmap.h>
+
+/* I2C addresses of MUIC internal registers */
+#define MAX14526_DEVICE_ID	0x00
+#define MAX14526_ID		0x02
+
+/* CONTROL_1 register masks */
+#define MAX14526_CONTROL_1	0x01
+#define   ID_2P2		BIT(6)
+#define   ID_620		BIT(5)
+#define   ID_200		BIT(4)
+#define   VLDO			BIT(3)
+#define   SEMREN		BIT(2)
+#define   ADC_EN		BIT(1)
+#define   CP_EN			BIT(0)
+
+/* CONTROL_2 register masks */
+#define MAX14526_CONTROL_2	0x02
+#define   INTPOL		BIT(7)
+#define   INT_EN		BIT(6)
+#define   MIC_LP		BIT(5)
+#define   CP_AUD		BIT(4)
+#define   CHG_TYPE		BIT(1)
+#define   USB_DET_DIS		BIT(0)
+
+/* SW_CONTROL register masks */
+#define MAX14526_SW_CONTROL	0x03
+#define   SW_DATA		0x00
+#define   SW_UART		0x01
+#define   SW_AUDIO		0x02
+#define   SW_OPEN		0x07
+
+/* INT_STATUS register masks */
+#define MAX14526_INT_STAT	0x04
+#define   CHGDET		BIT(7)
+#define   MR_COMP		BIT(6)
+#define   SENDEND		BIT(5)
+#define   V_VBUS		BIT(4)
+
+/* STATUS register masks */
+#define MAX14526_STATUS		0x05
+#define   CPORT			BIT(7)
+#define   CHPORT		BIT(6)
+#define   C1COMP		BIT(0)
+
+enum max14526_idno_resistance {
+	MAX14526_GND,
+	MAX14526_24KOHM,
+	MAX14526_56KOHM,
+	MAX14526_100KOHM,
+	MAX14526_130KOHM,
+	MAX14526_180KOHM,
+	MAX14526_240KOHM,
+	MAX14526_330KOHM,
+	MAX14526_430KOHM,
+	MAX14526_620KOHM,
+	MAX14526_910KOHM,
+	MAX14526_OPEN
+};
+
+enum max14526_field_idx {
+	VENDOR_ID, CHIP_REV,		/* DEVID */
+	DM, DP,				/* SW_CONTROL */
+	MAX14526_N_REGMAP_FIELDS
+};
+
+static const struct reg_field max14526_reg_field[MAX14526_N_REGMAP_FIELDS] = {
+	[VENDOR_ID] = REG_FIELD(MAX14526_DEVICE_ID,  4, 7),
+	[CHIP_REV]  = REG_FIELD(MAX14526_DEVICE_ID,  0, 3),
+	[DM]        = REG_FIELD(MAX14526_SW_CONTROL, 0, 2),
+	[DP]        = REG_FIELD(MAX14526_SW_CONTROL, 3, 5),
+};
+
+struct max14526_data {
+	struct i2c_client *client;
+	struct extcon_dev *edev;
+
+	struct regmap *regmap;
+	struct regmap_field *rfield[MAX14526_N_REGMAP_FIELDS];
+
+	int last_state;
+	int cable;
+};
+
+enum max14526_muic_modes {
+	MAX14526_OTG     = MAX14526_GND, /* no power */
+	MAX14526_MHL     = MAX14526_56KOHM, /* no power */
+	MAX14526_OTG_Y   = MAX14526_GND | V_VBUS,
+	MAX14526_MHL_CHG = MAX14526_GND | V_VBUS | CHGDET,
+	MAX14526_NONE    = MAX14526_OPEN,
+	MAX14526_USB     = MAX14526_OPEN | V_VBUS,
+	MAX14526_CHG     = MAX14526_OPEN | V_VBUS | CHGDET,
+};
+
+static const unsigned int max14526_extcon_cable[] = {
+	EXTCON_USB,
+	EXTCON_USB_HOST,
+	EXTCON_CHG_USB_FAST,
+	EXTCON_DISP_MHL,
+	EXTCON_NONE,
+};
+
+static int max14526_ap_usb_mode(struct max14526_data *priv)
+{
+	struct device *dev = &priv->client->dev;
+	int ret;
+
+	/* Enable USB Path */
+	ret = regmap_field_write(priv->rfield[DM], SW_DATA);
+	if (ret)
+		return ret;
+
+	ret = regmap_field_write(priv->rfield[DP], SW_DATA);
+	if (ret)
+		return ret;
+
+	/* Enable 200K, Charger Pump and ADC */
+	ret = regmap_write(priv->regmap, MAX14526_CONTROL_1,
+			   ID_200 | ADC_EN | CP_EN);
+	if (ret)
+		return ret;
+
+	dev_dbg(dev, "AP USB mode set\n");
+
+	return 0;
+}
+
+static irqreturn_t max14526_interrupt(int irq, void *dev_id)
+{
+	struct max14526_data *priv = dev_id;
+	struct device *dev = &priv->client->dev;
+	int state, ret;
+
+	/*
+	 * Upon an MUIC IRQ (MUIC_INT_N falls), wait at least 70ms
+	 * before reading INT_STAT and STATUS. After the reads,
+	 * MUIC_INT_N returns to high (but the INT_STAT and STATUS
+	 * contents will be held).
+	 */
+	msleep(100);
+
+	ret = regmap_read(priv->regmap, MAX14526_INT_STAT, &state);
+	if (ret)
+		dev_err(dev, "failed to read MUIC state %d\n", ret);
+
+	if (state == priv->last_state)
+		return IRQ_HANDLED;
+
+	/* Detach previous device */
+	extcon_set_state_sync(priv->edev, priv->cable, false);
+
+	switch (state) {
+	case MAX14526_USB:
+		priv->cable = EXTCON_USB;
+		break;
+
+	case MAX14526_CHG:
+		priv->cable = EXTCON_CHG_USB_FAST;
+		break;
+
+	case MAX14526_OTG:
+	case MAX14526_OTG_Y:
+		priv->cable = EXTCON_USB_HOST;
+		break;
+
+	case MAX14526_MHL:
+	case MAX14526_MHL_CHG:
+		priv->cable = EXTCON_DISP_MHL;
+		break;
+
+	case MAX14526_NONE:
+	default:
+		priv->cable = EXTCON_NONE;
+		break;
+	}
+
+	extcon_set_state_sync(priv->edev, priv->cable, true);
+
+	priv->last_state = state;
+
+	return IRQ_HANDLED;
+}
+
+static const struct regmap_config max14526_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = MAX14526_STATUS,
+};
+
+static int max14526_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct max14526_data *priv;
+	int ret, dev_id, rev, i;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->client = client;
+	i2c_set_clientdata(client, priv);
+
+	priv->regmap = devm_regmap_init_i2c(client, &max14526_regmap_config);
+	if (IS_ERR(priv->regmap))
+		return dev_err_probe(dev, PTR_ERR(priv->regmap), "cannot allocate regmap\n");
+
+	for (i = 0; i < MAX14526_N_REGMAP_FIELDS; i++) {
+		priv->rfield[i] = devm_regmap_field_alloc(dev, priv->regmap,
+							  max14526_reg_field[i]);
+		if (IS_ERR(priv->rfield[i]))
+			return dev_err_probe(dev, PTR_ERR(priv->rfield[i]),
+					     "cannot allocate regmap field\n");
+	}
+
+	/* Detect if MUIC version is supported */
+	ret = regmap_field_read(priv->rfield[VENDOR_ID], &dev_id);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to read MUIC ID\n");
+
+	regmap_field_read(priv->rfield[CHIP_REV], &rev);
+
+	if (dev_id == MAX14526_ID)
+		dev_info(dev, "detected MAX14526 MUIC with id 0x%x, rev 0x%x\n", dev_id, rev);
+	else
+		dev_err_probe(dev, -EINVAL, "MUIC vendor id 0x%X is not recognized\n", dev_id);
+
+	priv->edev = devm_extcon_dev_allocate(dev, max14526_extcon_cable);
+	if (IS_ERR(priv->edev))
+		return dev_err_probe(dev, (IS_ERR(priv->edev)),
+				     "failed to allocate extcon device\n");
+
+	ret = devm_extcon_dev_register(dev, priv->edev);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "failed to register extcon device\n");
+
+	ret = max14526_ap_usb_mode(priv);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "failed to set AP USB mode\n");
+
+	regmap_write_bits(priv->regmap, MAX14526_CONTROL_2, INT_EN, INT_EN);
+	regmap_write_bits(priv->regmap, MAX14526_CONTROL_2, USB_DET_DIS, (u32)~USB_DET_DIS);
+
+	ret = devm_request_threaded_irq(dev, client->irq, NULL, &max14526_interrupt,
+					IRQF_ONESHOT | IRQF_SHARED, client->name, priv);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to register IRQ\n");
+
+	irq_wake_thread(client->irq, priv);
+
+	return 0;
+}
+
+static int max14526_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct max14526_data *priv = i2c_get_clientdata(client);
+
+	irq_wake_thread(client->irq, priv);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(max14526_pm_ops, NULL, max14526_resume);
+
+static const struct of_device_id max14526_match[] = {
+	{ .compatible = "maxim,max14526" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, max14526_match);
+
+static const struct i2c_device_id max14526_id[] = {
+	{ "max14526" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max14526_id);
+
+static struct i2c_driver max14526_driver = {
+	.driver = {
+		.name = "max14526",
+		.of_match_table = max14526_match,
+		.pm = &max14526_pm_ops,
+	},
+	.probe = max14526_probe,
+	.id_table = max14526_id,
+};
+module_i2c_driver(max14526_driver);
+
+MODULE_AUTHOR("Svyatoslav Ryhel <clamor95@gmail.com>");
+MODULE_DESCRIPTION("MAX14526 extcon driver to support MUIC");
+MODULE_LICENSE("GPL");
-- 
2.48.1

Re: [PATCH v3 0/2] extcon: add basic Maxim MAX14526 MUIC support

[Chanwoo Choi]

Hi,

Applied them.

Thanks,


On Tue, May 6, 2025 at 5:09 PM Svyatoslav Ryhel <clamor95@gmail.com> wrote:
>
> The MAX14526 is a simple multiplexer of common inputs on a single
> mini/micro USB for portable devices.
>
> ---
> Changes on switching from v2 to v3:
> - fixed overflow issue with ~USB_DET_DIS
>
> Changes on switching from v1 to v2:
> - added port and connector to schema
> - removed -muic suffix
> - removed unneded comment header
> - removed unneded gpios in private data
> - improved code formatting
> ---
>
> Svyatoslav Ryhel (2):
>   dt-bindings: extcon: Document Maxim MAX14526 MUIC
>   extcon: Add basic support for Maxim MAX14526 MUIC
>
>  .../bindings/extcon/maxim,max14526.yaml       |  80 +++++
>  drivers/extcon/Kconfig                        |  12 +
>  drivers/extcon/Makefile                       |   1 +
>  drivers/extcon/extcon-max14526.c              | 302 ++++++++++++++++++
>  4 files changed, 395 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/extcon/maxim,max14526.yaml
>  create mode 100644 drivers/extcon/extcon-max14526.c
>
> --
> 2.48.1
>
>


--
Best Regards,
Chanwoo Choi
Samsung Electronics