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authorMichael Auchter <michael.auchter@ni.com>2020-10-15 17:07:34 +0300
committerChanwoo Choi <cw00.choi@samsung.com>2020-12-11 11:01:09 +0300
commit06bc4ca115cddabba0faa801488bd946a48c0bf7 (patch)
tree3a91e65b8bdf491b18b5e2a1c3f379f5ba234815 /drivers/extcon/extcon-usbc-tusb320.c
parent0477e92881850d44910a7e94fc2c46f96faa131f (diff)
downloadlinux-06bc4ca115cddabba0faa801488bd946a48c0bf7.tar.xz
extcon: Add driver for TI TUSB320
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.auchter@ni.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Diffstat (limited to 'drivers/extcon/extcon-usbc-tusb320.c')
-rw-r--r--drivers/extcon/extcon-usbc-tusb320.c184
1 files changed, 184 insertions, 0 deletions
diff --git a/drivers/extcon/extcon-usbc-tusb320.c b/drivers/extcon/extcon-usbc-tusb320.c
new file mode 100644
index 000000000000..805af73b4152
--- /dev/null
+++ b/drivers/extcon/extcon-usbc-tusb320.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * drivers/extcon/extcon-tusb320.c - TUSB320 extcon driver
+ *
+ * Copyright (C) 2020 National Instruments Corporation
+ * Author: Michael Auchter <michael.auchter@ni.com>
+ */
+
+#include <linux/extcon-provider.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/interrupt.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, &reg)) {
+ 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 PTR_ERR(priv->edev);
+ }
+
+ 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,
+ client->name, 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 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.auchter@ni.com>");
+MODULE_DESCRIPTION("TI TUSB320 extcon driver");
+MODULE_LICENSE("GPL v2");