[PATCH v3 3/3] extcon: add MAX14526 MUIC support

[Svyatoslav Ryhel]

MAX14526 is a powerful extcon chip which allows detection of various
plugs like usb, mhl, uart, headset etc. This version of driver
implements support of AP-usb and CP-usb/uart paths.

Tested-by: Andreas Westman Dorcsak <hedmoo at yahoo.com> # LG P880 T30
Tested-by: Svyatoslav Ryhel <clamor95 at gmail.com> # LG P895 T30
Signed-off-by: Svyatoslav Ryhel <clamor95 at gmail.com>
---
 drivers/extcon/Kconfig           |   9 ++
 drivers/extcon/Makefile          |   1 +
 drivers/extcon/extcon-max14526.c | 151 +++++++++++++++++++++++++++++++
 3 files changed, 161 insertions(+)
 create mode 100644 drivers/extcon/extcon-max14526.c

diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
index 6fd3d2b97b..fbb73354aa 100644
--- a/drivers/extcon/Kconfig
+++ b/drivers/extcon/Kconfig
@@ -19,4 +19,13 @@ config EXTCON_SANDBOX
 	  Enable extcon support for sandbox. This is an emulation of a real
 	  extcon. Currectly all configuration is done in the probe.
 
+config EXTCON_MAX14526
+	bool "Maxim MAX14526 EXTCON Support"
+	depends on DM_I2C
+	depends on EXTCON
+	help
+	  If you say yes here you get support for the MUIC device of
+	  Maxim MAX14526. The MAX14526 MUIC is a USB port accessory
+	  detector and switch.
+
 endmenu
diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
index c4223d97d1..3309f2aac2 100644
--- a/drivers/extcon/Makefile
+++ b/drivers/extcon/Makefile
@@ -4,3 +4,4 @@
 
 obj-$(CONFIG_EXTCON) += extcon-uclass.o
 obj-$(CONFIG_EXTCON_SANDBOX) += extcon-sandbox.o
+obj-$(CONFIG_EXTCON_MAX14526) += extcon-max14526.o
diff --git a/drivers/extcon/extcon-max14526.c b/drivers/extcon/extcon-max14526.c
new file mode 100644
index 0000000000..a33b5ef919
--- /dev/null
+++ b/drivers/extcon/extcon-max14526.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2022 Svyatoslav Ryhel <clamor95 at gmail.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <i2c.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <log.h>
+#include <extcon.h>
+#include <asm/gpio.h>
+
+#define CONTROL_1	0x01
+#define SW_CONTROL	0x03
+
+#define ID_200		0x10
+#define ADC_EN		0x02
+#define CP_EN		0x01
+
+#define DP_USB		0x00
+#define DP_UART		0x08
+#define DP_AUDIO	0x10
+#define DP_OPEN		0x38
+
+#define DM_USB		0x00
+#define DM_UART		0x01
+#define DM_AUDIO	0x02
+#define DM_OPEN		0x07
+
+#define AP_USB		BIT(0)
+#define CP_USB		BIT(1)
+#define CP_UART		BIT(2)
+
+struct max14526_priv {
+	struct gpio_desc usif_gpio;
+	struct gpio_desc dp2t_gpio;
+	struct gpio_desc ifx_usb_vbus_gpio;
+};
+
+static void max14526_set_mode(struct udevice *dev, int mode)
+{
+	struct max14526_priv *priv = dev_get_priv(dev);
+	int ret;
+
+	if ((mode & AP_USB) || (mode & CP_USB)) {
+		/* Connect CP UART signals to AP */
+		ret = dm_gpio_set_value(&priv->usif_gpio, 0);
+		if (ret)
+			log_debug("cp-uart > ap failed (%d)\n", ret);
+	}
+
+	if (mode & CP_UART) {
+		/* Connect CP UART signals to DP2T */
+		ret = dm_gpio_set_value(&priv->usif_gpio, 1);
+		if (ret)
+			log_debug("cp-uart > dp2t failed (%d)\n", ret);
+	}
+
+	if (mode & CP_USB) {
+		/* Connect CP USB to MUIC UART */
+		ret = dm_gpio_set_value(&priv->ifx_usb_vbus_gpio, 1);
+		if (ret)
+			log_debug("usb-vbus-gpio enable failed (%d)\n", ret);
+
+		ret = dm_gpio_set_value(&priv->dp2t_gpio, 1);
+		if (ret)
+			log_debug("cp-usb > muic-uart failed (%d)\n", ret);
+	}
+
+	if ((mode & AP_USB) || (mode & CP_UART)) {
+		/* Connect CP UART to MUIC UART */
+		ret = dm_gpio_set_value(&priv->dp2t_gpio, 0);
+		if (ret)
+			log_debug("cp-uart > muic-uart failed (%d)\n", ret);
+	}
+
+	if (mode & AP_USB) {
+		/* Enables USB Path */
+		ret = dm_i2c_reg_write(dev, SW_CONTROL, DP_USB | DM_USB);
+		if (ret)
+			log_debug("USB path set failed: %d\n", ret);
+	}
+
+	if ((mode & CP_USB) || (mode & CP_UART)) {
+		/* Enables UART Path */
+		ret = dm_i2c_reg_write(dev, SW_CONTROL, DP_UART | DM_UART);
+		if (ret)
+			log_debug("UART path set failed: %d\n", ret);
+	}
+
+	/* Enables 200K, Charger Pump, and ADC */
+	ret = dm_i2c_reg_write(dev, CONTROL_1, ID_200 | ADC_EN | CP_EN);
+	if (ret)
+		log_debug("200K, Charger Pump, and ADC set failed: %d\n", ret);
+}
+
+static int max14526_probe(struct udevice *dev)
+{
+	struct max14526_priv *priv = dev_get_priv(dev);
+	int ret, mode = 0;
+
+	ret = gpio_request_by_name(dev, "usif-gpios", 0,
+				   &priv->usif_gpio, GPIOD_IS_OUT);
+	if (ret) {
+		log_err("could not decode usif-gpios (%d)\n", ret);
+		return ret;
+	}
+
+	ret = gpio_request_by_name(dev, "dp2t-gpios", 0,
+				   &priv->dp2t_gpio, GPIOD_IS_OUT);
+	if (ret) {
+		log_err("could not decode dp2t-gpios (%d)\n", ret);
+		return ret;
+	}
+
+	if (dev_read_bool(dev, "maxim,ap-usb"))
+		mode |= AP_USB;
+
+	if (dev_read_bool(dev, "maxim,cp-usb")) {
+		mode |= CP_USB;
+
+		ret = gpio_request_by_name(dev, "usb-vbus-gpios", 0,
+					   &priv->ifx_usb_vbus_gpio, GPIOD_IS_OUT);
+		if (ret) {
+			log_err("could not decode usb-vbus-gpios (%d)\n", ret);
+			return ret;
+		}
+	}
+
+	if (dev_read_bool(dev, "maxim,cp-uart"))
+		mode |= CP_UART;
+
+	max14526_set_mode(dev, mode);
+
+	return 0;
+}
+
+static const struct udevice_id max14526_ids[] = {
+	{ .compatible = "maxim,max14526-muic" },
+	{ }
+};
+
+U_BOOT_DRIVER(extcon_max14526) = {
+	.name		= "extcon_max14526",
+	.id		= UCLASS_EXTCON,
+	.of_match	= max14526_ids,
+	.probe		= max14526_probe,
+	.priv_auto	= sizeof(struct max14526_priv),
+};
-- 
2.37.2