USB: misc: Add USB3503 High-Speed Hub Controller

This patch adds new driver of SMSC USB3503 USB 2.0 hub controller with HSIC
upstream connectivity and three USB 2.0 downstream ports. The specification
can be found from 'http://www.smsc.com/index.php?tid=295&pid=325'.

The current version have been tested very basic features switching the modes,
HUB-MODE and STANDBY-MODE.

Signed-off-by: Dongjin Kim <tobetter@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 303 insertions, 0 deletions

diff --git a/drivers/usb/misc/usb3503.c b/drivers/usb/misc/usb3503.c
new file mode 100644
index 000000000000..796d58c95b63
--- /dev/null
+++ b/drivers/usb/misc/usb3503.c
@@ -0,0 +1,303 @@
+/*
+ * Driver for SMSC USB3503 USB 2.0 hub controller driver
+ *
+ * Copyright (c) 2012-2013 Dongjin Kim (tobetter@gmail.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/i2c.h>
+#include <linux/gpio.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/usb3503.h>
+
+#define USB3503_VIDL		0x00
+#define USB3503_VIDM		0x01
+#define USB3503_PIDL		0x02
+#define USB3503_PIDM		0x03
+#define USB3503_DIDL		0x04
+#define USB3503_DIDM		0x05
+
+#define USB3503_CFG1		0x06
+#define USB3503_SELF_BUS_PWR	(1 << 7)
+
+#define USB3503_CFG2		0x07
+#define USB3503_CFG3		0x08
+#define USB3503_NRD		0x09
+
+#define USB3503_PDS		0x0a
+#define USB3503_PORT1		(1 << 1)
+#define USB3503_PORT2		(1 << 2)
+#define USB3503_PORT3		(1 << 3)
+
+#define USB3503_SP_ILOCK	0xe7
+#define USB3503_SPILOCK_CONNECT	(1 << 1)
+#define USB3503_SPILOCK_CONFIG	(1 << 0)
+
+#define USB3503_CFGP		0xee
+#define USB3503_CLKSUSP		(1 << 7)
+
+struct usb3503 {
+	enum usb3503_mode	mode;
+	struct i2c_client	*client;
+	int	gpio_intn;
+	int	gpio_reset;
+	int	gpio_connect;
+};
+
+static int usb3503_write_register(struct i2c_client *client,
+		char reg, char data)
+{
+	return i2c_smbus_write_byte_data(client, reg, data);
+}
+
+static int usb3503_read_register(struct i2c_client *client, char reg)
+{
+	return i2c_smbus_read_byte_data(client, reg);
+}
+
+static int usb3503_set_bits(struct i2c_client *client, char reg, char req)
+{
+	int err;
+
+	err = usb3503_read_register(client, reg);
+	if (err < 0)
+		return err;
+
+	err = usb3503_write_register(client, reg, err | req);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static int usb3503_clear_bits(struct i2c_client *client, char reg, char req)
+{
+	int err;
+
+	err = usb3503_read_register(client, reg);
+	if (err < 0)
+		return err;
+
+	err = usb3503_write_register(client, reg, err & ~req);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static int usb3503_reset(int gpio_reset, int state)
+{
+	if (gpio_is_valid(gpio_reset))
+		gpio_set_value(gpio_reset, state);
+
+	/* Wait RefClk when RESET_N is released, otherwise Hub will
+	 * not transition to Hub Communication Stage.
+	 */
+	if (state)
+		msleep(100);
+
+	return 0;
+}
+
+static int usb3503_switch_mode(struct usb3503 *hub, enum usb3503_mode mode)
+{
+	struct i2c_client *i2c = hub->client;
+	int err = 0;
+
+	switch (mode) {
+	case USB3503_MODE_HUB:
+		usb3503_reset(hub->gpio_reset, 1);
+
+		/* SP_ILOCK: set connect_n, config_n for config */
+		err = usb3503_write_register(i2c, USB3503_SP_ILOCK,
+				(USB3503_SPILOCK_CONNECT
+				 | USB3503_SPILOCK_CONFIG));
+		if (err < 0) {
+			dev_err(&i2c->dev, "SP_ILOCK failed (%d)\n", err);
+			goto err_hubmode;
+		}
+
+		/* PDS : Port2,3 Disable For Self Powered Operation */
+		err = usb3503_set_bits(i2c, USB3503_PDS,
+				(USB3503_PORT2 | USB3503_PORT3));
+		if (err < 0) {
+			dev_err(&i2c->dev, "PDS failed (%d)\n", err);
+			goto err_hubmode;
+		}
+
+		/* CFG1 : SELF_BUS_PWR -> Self-Powerd operation */
+		err = usb3503_set_bits(i2c, USB3503_CFG1, USB3503_SELF_BUS_PWR);
+		if (err < 0) {
+			dev_err(&i2c->dev, "CFG1 failed (%d)\n", err);
+			goto err_hubmode;
+		}
+
+		/* SP_LOCK: clear connect_n, config_n for hub connect */
+		err = usb3503_clear_bits(i2c, USB3503_SP_ILOCK,
+				(USB3503_SPILOCK_CONNECT
+				 | USB3503_SPILOCK_CONFIG));
+		if (err < 0) {
+			dev_err(&i2c->dev, "SP_ILOCK failed (%d)\n", err);
+			goto err_hubmode;
+		}
+
+		hub->mode = mode;
+		dev_info(&i2c->dev, "switched to HUB mode\n");
+		break;
+
+	case USB3503_MODE_STANDBY:
+		usb3503_reset(hub->gpio_reset, 0);
+
+		hub->mode = mode;
+		dev_info(&i2c->dev, "switched to STANDBY mode\n");
+		break;
+
+	default:
+		dev_err(&i2c->dev, "unknown mode is request\n");
+		err = -EINVAL;
+		break;
+	}
+
+err_hubmode:
+	return err;
+}
+
+int usb3503_probe(struct i2c_client *i2c, const struct i2c_device_id *id)
+{
+	struct usb3503_platform_data *pdata = i2c->dev.platform_data;
+	struct usb3503 *hub;
+	int err;
+
+	hub = kzalloc(sizeof(struct usb3503), GFP_KERNEL);
+	if (!hub) {
+		dev_err(&i2c->dev, "private data alloc fail\n");
+		return -ENOMEM;
+	}
+
+	i2c_set_clientdata(i2c, hub);
+	hub->client = i2c;
+
+	if (!pdata) {
+		dev_dbg(&i2c->dev, "missing platform data\n");
+	} else {
+		hub->gpio_intn		= pdata->gpio_intn;
+		hub->gpio_connect	= pdata->gpio_connect;
+		hub->gpio_reset		= pdata->gpio_reset;
+		hub->mode		= pdata->initial_mode;
+	}
+
+	if (gpio_is_valid(hub->gpio_intn)) {
+		err = gpio_request_one(hub->gpio_intn,
+				GPIOF_OUT_INIT_HIGH, "usb3503 intn");
+		if (err) {
+			dev_err(&i2c->dev,
+					"unable to request GPIO %d as connect pin (%d)\n",
+					hub->gpio_intn, err);
+			goto err_gpio_intn;
+		}
+	}
+
+	if (gpio_is_valid(hub->gpio_connect)) {
+		err = gpio_request_one(hub->gpio_connect,
+				GPIOF_OUT_INIT_HIGH, "usb3503 connect");
+		if (err) {
+			dev_err(&i2c->dev,
+					"unable to request GPIO %d as connect pin (%d)\n",
+					hub->gpio_connect, err);
+			goto err_gpio_connect;
+		}
+	}
+
+	if (gpio_is_valid(hub->gpio_reset)) {
+		err = gpio_request_one(hub->gpio_reset,
+				GPIOF_OUT_INIT_LOW, "usb3503 reset");
+		if (err) {
+			dev_err(&i2c->dev,
+					"unable to request GPIO %d as reset pin (%d)\n",
+					hub->gpio_reset, err);
+			goto err_gpio_reset;
+		}
+	}
+
+	usb3503_switch_mode(hub, pdata->initial_mode);
+
+	dev_info(&i2c->dev, "%s: probed on  %s mode\n", __func__,
+			(hub->mode == USB3503_MODE_HUB) ? "hub" : "standby");
+
+	return 0;
+
+err_gpio_reset:
+	if (gpio_is_valid(hub->gpio_connect))
+		gpio_free(hub->gpio_connect);
+err_gpio_connect:
+	if (gpio_is_valid(hub->gpio_intn))
+		gpio_free(hub->gpio_intn);
+err_gpio_intn:
+	kfree(hub);
+
+	return err;
+}
+
+static int usb3503_remove(struct i2c_client *i2c)
+{
+	struct usb3503 *hub = i2c_get_clientdata(i2c);
+
+	if (gpio_is_valid(hub->gpio_intn))
+		gpio_free(hub->gpio_intn);
+	if (gpio_is_valid(hub->gpio_connect))
+		gpio_free(hub->gpio_connect);
+	if (gpio_is_valid(hub->gpio_reset))
+		gpio_free(hub->gpio_reset);
+
+	kfree(hub);
+
+	return 0;
+}
+
+static const struct i2c_device_id usb3503_id[] = {
+	{ USB3503_I2C_NAME, 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, usb3503_id);
+
+static struct i2c_driver usb3503_driver = {
+	.driver = {
+		.name = USB3503_I2C_NAME,
+	},
+	.probe		= usb3503_probe,
+	.remove		= usb3503_remove,
+	.id_table	= usb3503_id,
+};
+
+static int __init usb3503_init(void)
+{
+	return i2c_add_driver(&usb3503_driver);
+}
+
+static void __exit usb3503_exit(void)
+{
+	i2c_del_driver(&usb3503_driver);
+}
+
+module_init(usb3503_init);
+module_exit(usb3503_exit);
+
+MODULE_AUTHOR("Dongjin Kim <tobetter@gmail.com>");
+MODULE_DESCRIPTION("USB3503 USB HUB driver");
+MODULE_LICENSE("GPL");