--- /dev/null
+/*
+ * 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");