This patch adds an extcon driver for the TI TUSB320 USB Type-C device.
This can be used to detect whether the port is configured as a
downstream or upstream facing port.
Signed-off-by: Michael Auchter <michael.auch...@ni.com>
---
Changes since v1:
- Drop license text that's redundant with SPDX tag
- Cleanup, sort list of includes
- Add additional register defines
- Switch to use regmap API
- Fix Kconfig to depend on I2C, not GPIOLIB
drivers/extcon/Kconfig | 8 ++
drivers/extcon/Makefile | 1 +
drivers/extcon/extcon-usbc-tusb320.c | 191 +++++++++++++++++++++++++++
3 files changed, 200 insertions(+)
create mode 100644 drivers/extcon/extcon-usbc-tusb320.c
diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
index aac507bff135..af58ebca2bf6 100644
--- a/drivers/extcon/Kconfig
+++ b/drivers/extcon/Kconfig
@@ -186,4 +186,12 @@ config EXTCON_USBC_CROS_EC
Say Y here to enable USB Type C cable detection extcon support when
using Chrome OS EC based USB Type-C ports.
+config EXTCON_USBC_TUSB320
+ tristate "TI TUSB320 USB-C extcon support"
+ depends on I2C
+ select REGMAP_I2C
+ help
+ Say Y here to enable support for USB Type C cable detection extcon
+ support using a TUSB320.
+
endif
diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
index 52096fd8a216..fe10a1b7d18b 100644
--- a/drivers/extcon/Makefile
+++ b/drivers/extcon/Makefile
@@ -25,3 +25,4 @@ obj-$(CONFIG_EXTCON_RT8973A) += extcon-rt8973a.o
obj-$(CONFIG_EXTCON_SM5502) += extcon-sm5502.o
obj-$(CONFIG_EXTCON_USB_GPIO) += extcon-usb-gpio.o
obj-$(CONFIG_EXTCON_USBC_CROS_EC) += extcon-usbc-cros-ec.o
+obj-$(CONFIG_EXTCON_USBC_TUSB320) += extcon-usbc-tusb320.o
diff --git a/drivers/extcon/extcon-usbc-tusb320.c
b/drivers/extcon/extcon-usbc-tusb320.c
new file mode 100644
index 000000000000..93f1843ca89b
--- /dev/null
+++ b/drivers/extcon/extcon-usbc-tusb320.c
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * drivers/extcon/extcon-tusb320.c - TUSB320 extcon driver
+ *
+ * Copyright (C) 2020 National Instruments Corporation
+ * Author: Michael Auchter <michael.auch...@ni.com>
+ */
+
+#include <linux/extcon-provider.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#define TUSB320_REG9 0x9
+#define TUSB320_REG9_ATTACHED_STATE_SHIFT 6
+#define TUSB320_REG9_ATTACHED_STATE_MASK 0x3
+#define TUSB320_REG9_CABLE_DIRECTION BIT(5)
+#define TUSB320_REG9_INTERRUPT_STATUS BIT(4)
+#define TUSB320_ATTACHED_STATE_NONE 0x0
+#define TUSB320_ATTACHED_STATE_DFP 0x1
+#define TUSB320_ATTACHED_STATE_UFP 0x2
+#define TUSB320_ATTACHED_STATE_ACC 0x3
+
+struct tusb320_priv {
+ struct device *dev;
+ struct regmap *regmap;
+ struct extcon_dev *edev;
+};
+
+static const char * const tusb_attached_states[] = {
+ [TUSB320_ATTACHED_STATE_NONE] = "not attached",
+ [TUSB320_ATTACHED_STATE_DFP] = "downstream facing port",
+ [TUSB320_ATTACHED_STATE_UFP] = "upstream facing port",
+ [TUSB320_ATTACHED_STATE_ACC] = "accessory",
+};
+
+static const unsigned int tusb320_extcon_cable[] = {
+ EXTCON_USB,
+ EXTCON_USB_HOST,
+ EXTCON_NONE,
+};
+
+static int tusb320_check_signature(struct tusb320_priv *priv)
+{
+ static const char sig[] = { '\0', 'T', 'U', 'S', 'B', '3', '2', '0' };
+ unsigned val;
+ int i, ret;
+
+ for (i = 0; i < sizeof(sig); i++) {
+ ret = regmap_read(priv->regmap, sizeof(sig) - 1 - i, &val);
+ if (ret < 0)
+ return ret;
+ if (val != sig[i]) {
+ dev_err(priv->dev, "signature mismatch!\n");
+ return -ENODEV;
+ }
+ }
+
+ return 0;
+}
+
+static irqreturn_t tusb320_irq_handler(int irq, void *dev_id)
+{
+ struct tusb320_priv *priv = dev_id;
+ int state, polarity;
+ unsigned reg;
+
+ if (regmap_read(priv->regmap, TUSB320_REG9, ®)) {
+ dev_err(priv->dev, "error during i2c read!\n");
+ return IRQ_NONE;
+ }
+
+ if (!(reg & TUSB320_REG9_INTERRUPT_STATUS))
+ return IRQ_NONE;
+
+ state = (reg >> TUSB320_REG9_ATTACHED_STATE_SHIFT) &
+ TUSB320_REG9_ATTACHED_STATE_MASK;
+ polarity = !!(reg & TUSB320_REG9_CABLE_DIRECTION);
+
+ dev_dbg(priv->dev, "attached state: %s, polarity: %d\n",
+ tusb_attached_states[state], polarity);
+
+ extcon_set_state(priv->edev, EXTCON_USB,
+ state == TUSB320_ATTACHED_STATE_UFP);
+ extcon_set_state(priv->edev, EXTCON_USB_HOST,
+ state == TUSB320_ATTACHED_STATE_DFP);
+ extcon_set_property(priv->edev, EXTCON_USB,
+ EXTCON_PROP_USB_TYPEC_POLARITY,
+ (union extcon_property_value)polarity);
+ extcon_set_property(priv->edev, EXTCON_USB_HOST,
+ EXTCON_PROP_USB_TYPEC_POLARITY,
+ (union extcon_property_value)polarity);
+ extcon_sync(priv->edev, EXTCON_USB);
+ extcon_sync(priv->edev, EXTCON_USB_HOST);
+
+ regmap_write(priv->regmap, TUSB320_REG9, reg);
+
+ return IRQ_HANDLED;
+}
+
+static const struct regmap_config tusb320_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+};
+
+static int tusb320_extcon_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct tusb320_priv *priv;
+ int ret;
+
+ priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+ priv->dev = &client->dev;
+
+ priv->regmap = devm_regmap_init_i2c(client, &tusb320_regmap_config);
+ if (IS_ERR(priv->regmap))
+ return PTR_ERR(priv->regmap);
+
+ ret = tusb320_check_signature(priv);
+ if (ret)
+ return ret;
+
+ priv->edev = devm_extcon_dev_allocate(priv->dev, tusb320_extcon_cable);
+ if (IS_ERR(priv->edev)) {
+ dev_err(priv->dev, "failed to allocate extcon device\n");
+ return -ENOMEM;
+ }
+
+ ret = devm_extcon_dev_register(priv->dev, priv->edev);
+ if (ret < 0) {
+ dev_err(priv->dev, "failed to register extcon device\n");
+ return ret;
+ }
+
+ extcon_set_property_capability(priv->edev, EXTCON_USB,
+ EXTCON_PROP_USB_TYPEC_POLARITY);
+ extcon_set_property_capability(priv->edev, EXTCON_USB_HOST,
+ EXTCON_PROP_USB_TYPEC_POLARITY);
+
+ /* update initial state */
+ tusb320_irq_handler(client->irq, priv);
+
+ ret = devm_request_threaded_irq(priv->dev, client->irq, NULL,
+ tusb320_irq_handler,
+ IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+ dev_name(priv->dev), priv);
+
+ return ret;
+}
+
+static const struct of_device_id tusb320_extcon_dt_match[] = {
+ { .compatible = "ti,tusb320", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, tusb320_extcon_dt_match);
+
+static const struct i2c_device_id tusb320_i2c_id[] = {
+ { "tusb320", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, tusb320_i2c_id);
+
+static struct i2c_driver tusb320_extcon_driver = {
+ .probe = tusb320_extcon_probe,
+ .driver = {
+ .name = "extcon-tusb320",
+ .of_match_table = tusb320_extcon_dt_match,
+ },
+};
+
+static int __init tusb320_init(void)
+{
+ return i2c_add_driver(&tusb320_extcon_driver);
+}
+subsys_initcall(tusb320_init);
+
+static void __exit tusb320_exit(void)
+{
+ i2c_del_driver(&tusb320_extcon_driver);
+}
+module_exit(tusb320_exit);
+
+MODULE_AUTHOR("Michael Auchter <michael.auch...@ni.com>");
+MODULE_DESCRIPTION("TI TUSB320 extcon driver");
+MODULE_LICENSE("GPL v2");
--
2.25.4
