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linux/drivers/usb/misc/usb3503.c
Tobias Jakobi 4463e15267 usb3503: clarify what the registers 'PDS' and 'CFG1' really do 
The current comment sounds like you have to disable some of
the ports to be able to use self-powered mode. This is
misleading, so change the wording to reflect this.

Signed-off-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23 22:15:18 -07:00

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/*
* 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/clk.h>
#include <linux/i2c.h>
#include <linux/gpio.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/of_gpio.h>
#include <linux/platform_device.h>
#include <linux/platform_data/usb3503.h>
#include <linux/regmap.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_SP_ILOCK 0xe7
#define USB3503_SPILOCK_CONNECT (1 << 1)
#define USB3503_SPILOCK_CONFIG (1 << 0)
#define USB3503_CFGP 0xee
#define USB3503_CLKSUSP (1 << 7)
#define USB3503_RESET 0xff
struct usb3503 {
enum usb3503_mode mode;
struct regmap *regmap;
struct device *dev;
struct clk *clk;
u8 port_off_mask;
int gpio_intn;
int gpio_reset;
int gpio_connect;
bool secondary_ref_clk;
};
static int usb3503_reset(struct usb3503 *hub, int state)
{
if (!state && gpio_is_valid(hub->gpio_connect))
gpio_set_value_cansleep(hub->gpio_connect, 0);
if (gpio_is_valid(hub->gpio_reset))
gpio_set_value_cansleep(hub->gpio_reset, state);
/* Wait T_HUBINIT == 4ms for hub logic to stabilize */
if (state)
usleep_range(4000, 10000);
return 0;
}
static int usb3503_connect(struct usb3503 *hub)
{
struct device *dev = hub->dev;
int err;
usb3503_reset(hub, 1);
if (hub->regmap) {
/* SP_ILOCK: set connect_n, config_n for config */
err = regmap_write(hub->regmap, USB3503_SP_ILOCK,
(USB3503_SPILOCK_CONNECT
| USB3503_SPILOCK_CONFIG));
if (err < 0) {
dev_err(dev, "SP_ILOCK failed (%d)\n", err);
return err;
}
/* PDS : Set the ports which are disabled in self-powered mode. */
if (hub->port_off_mask) {
err = regmap_update_bits(hub->regmap, USB3503_PDS,
hub->port_off_mask,
hub->port_off_mask);
if (err < 0) {
dev_err(dev, "PDS failed (%d)\n", err);
return err;
}
}
/* CFG1 : Set SELF_BUS_PWR, this enables self-powered operation. */
err = regmap_update_bits(hub->regmap, USB3503_CFG1,
USB3503_SELF_BUS_PWR,
USB3503_SELF_BUS_PWR);
if (err < 0) {
dev_err(dev, "CFG1 failed (%d)\n", err);
return err;
}
/* SP_LOCK: clear connect_n, config_n for hub connect */
err = regmap_update_bits(hub->regmap, USB3503_SP_ILOCK,
(USB3503_SPILOCK_CONNECT
| USB3503_SPILOCK_CONFIG), 0);
if (err < 0) {
dev_err(dev, "SP_ILOCK failed (%d)\n", err);
return err;
}
}
if (gpio_is_valid(hub->gpio_connect))
gpio_set_value_cansleep(hub->gpio_connect, 1);
hub->mode = USB3503_MODE_HUB;
dev_info(dev, "switched to HUB mode\n");
return 0;
}
static int usb3503_switch_mode(struct usb3503 *hub, enum usb3503_mode mode)
{
struct device *dev = hub->dev;
int err = 0;
switch (mode) {
case USB3503_MODE_HUB:
err = usb3503_connect(hub);
break;
case USB3503_MODE_STANDBY:
usb3503_reset(hub, 0);
dev_info(dev, "switched to STANDBY mode\n");
break;
default:
dev_err(dev, "unknown mode is requested\n");
err = -EINVAL;
break;
}
return err;
}
static const struct regmap_config usb3503_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = USB3503_RESET,
};
static int usb3503_probe(struct usb3503 *hub)
{
struct device *dev = hub->dev;
struct usb3503_platform_data *pdata = dev_get_platdata(dev);
struct device_node *np = dev->of_node;
int err;
u32 mode = USB3503_MODE_HUB;
const u32 *property;
int len;
if (pdata) {
hub->port_off_mask = pdata->port_off_mask;
hub->gpio_intn = pdata->gpio_intn;
hub->gpio_connect = pdata->gpio_connect;
hub->gpio_reset = pdata->gpio_reset;
hub->mode = pdata->initial_mode;
} else if (np) {
struct clk *clk;
hub->port_off_mask = 0;
clk = devm_clk_get(dev, "refclk");
if (IS_ERR(clk) && PTR_ERR(clk) != -ENOENT) {
dev_err(dev, "unable to request refclk (%ld)\n",
PTR_ERR(clk));
return PTR_ERR(clk);
}
if (!IS_ERR(clk)) {
u32 rate = 0;
hub->clk = clk;
if (!of_property_read_u32(np, "refclk-frequency",
&rate)) {
switch (rate) {
case 38400000:
case 26000000:
case 19200000:
case 12000000:
hub->secondary_ref_clk = 0;
break;
case 24000000:
case 27000000:
case 25000000:
case 50000000:
hub->secondary_ref_clk = 1;
break;
default:
dev_err(dev,
"unsupported reference clock rate (%d)\n",
(int) rate);
return -EINVAL;
}
err = clk_set_rate(hub->clk, rate);
if (err) {
dev_err(dev,
"unable to set reference clock rate to %d\n",
(int) rate);
return err;
}
}
err = clk_prepare_enable(hub->clk);
if (err) {
dev_err(dev,
"unable to enable reference clock\n");
return err;
}
}
property = of_get_property(np, "disabled-ports", &len);
if (property && (len / sizeof(u32)) > 0) {
int i;
for (i = 0; i < len / sizeof(u32); i++) {
u32 port = be32_to_cpu(property[i]);
if ((1 <= port) && (port <= 3))
hub->port_off_mask |= (1 << port);
}
}
hub->gpio_intn = of_get_named_gpio(np, "intn-gpios", 0);
if (hub->gpio_intn == -EPROBE_DEFER)
return -EPROBE_DEFER;
hub->gpio_connect = of_get_named_gpio(np, "connect-gpios", 0);
if (hub->gpio_connect == -EPROBE_DEFER)
return -EPROBE_DEFER;
hub->gpio_reset = of_get_named_gpio(np, "reset-gpios", 0);
if (hub->gpio_reset == -EPROBE_DEFER)
return -EPROBE_DEFER;
of_property_read_u32(np, "initial-mode", &mode);
hub->mode = mode;
}
if (hub->port_off_mask && !hub->regmap)
dev_err(dev, "Ports disabled with no control interface\n");
if (gpio_is_valid(hub->gpio_intn)) {
int val = hub->secondary_ref_clk ? GPIOF_OUT_INIT_LOW :
GPIOF_OUT_INIT_HIGH;
err = devm_gpio_request_one(dev, hub->gpio_intn, val,
"usb3503 intn");
if (err) {
dev_err(dev,
"unable to request GPIO %d as interrupt pin (%d)\n",
hub->gpio_intn, err);
return err;
}
}
if (gpio_is_valid(hub->gpio_connect)) {
err = devm_gpio_request_one(dev, hub->gpio_connect,
GPIOF_OUT_INIT_LOW, "usb3503 connect");
if (err) {
dev_err(dev,
"unable to request GPIO %d as connect pin (%d)\n",
hub->gpio_connect, err);
return err;
}
}
if (gpio_is_valid(hub->gpio_reset)) {
err = devm_gpio_request_one(dev, hub->gpio_reset,
GPIOF_OUT_INIT_LOW, "usb3503 reset");
if (err) {
dev_err(dev,
"unable to request GPIO %d as reset pin (%d)\n",
hub->gpio_reset, err);
return err;
}
}
usb3503_switch_mode(hub, hub->mode);
dev_info(dev, "%s: probed in %s mode\n", __func__,
(hub->mode == USB3503_MODE_HUB) ? "hub" : "standby");
return 0;
}
static int usb3503_i2c_probe(struct i2c_client *i2c,
const struct i2c_device_id *id)
{
struct usb3503 *hub;
int err;
hub = devm_kzalloc(&i2c->dev, sizeof(struct usb3503), GFP_KERNEL);
if (!hub) {
dev_err(&i2c->dev, "private data alloc fail\n");
return -ENOMEM;
}
i2c_set_clientdata(i2c, hub);
hub->regmap = devm_regmap_init_i2c(i2c, &usb3503_regmap_config);
if (IS_ERR(hub->regmap)) {
err = PTR_ERR(hub->regmap);
dev_err(&i2c->dev, "Failed to initialise regmap: %d\n", err);
return err;
}
hub->dev = &i2c->dev;
return usb3503_probe(hub);
}
static int usb3503_platform_probe(struct platform_device *pdev)
{
struct usb3503 *hub;
hub = devm_kzalloc(&pdev->dev, sizeof(struct usb3503), GFP_KERNEL);
if (!hub) {
dev_err(&pdev->dev, "private data alloc fail\n");
return -ENOMEM;
}
hub->dev = &pdev->dev;
return usb3503_probe(hub);
}
#ifdef CONFIG_PM_SLEEP
static int usb3503_i2c_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct usb3503 *hub = i2c_get_clientdata(client);
usb3503_switch_mode(hub, USB3503_MODE_STANDBY);
if (hub->clk)
clk_disable_unprepare(hub->clk);
return 0;
}
static int usb3503_i2c_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct usb3503 *hub = i2c_get_clientdata(client);
if (hub->clk)
clk_prepare_enable(hub->clk);
usb3503_switch_mode(hub, hub->mode);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(usb3503_i2c_pm_ops, usb3503_i2c_suspend,
usb3503_i2c_resume);
static const struct i2c_device_id usb3503_id[] = {
{ USB3503_I2C_NAME, 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, usb3503_id);
#ifdef CONFIG_OF
static const struct of_device_id usb3503_of_match[] = {
{ .compatible = "smsc,usb3503", },
{ .compatible = "smsc,usb3503a", },
{},
};
MODULE_DEVICE_TABLE(of, usb3503_of_match);
#endif
static struct i2c_driver usb3503_i2c_driver = {
.driver = {
.name = USB3503_I2C_NAME,
.pm = &usb3503_i2c_pm_ops,
.of_match_table = of_match_ptr(usb3503_of_match),
},
.probe = usb3503_i2c_probe,
.id_table = usb3503_id,
};
static struct platform_driver usb3503_platform_driver = {
.driver = {
.name = USB3503_I2C_NAME,
.of_match_table = of_match_ptr(usb3503_of_match),
.owner = THIS_MODULE,
},
.probe = usb3503_platform_probe,
};
static int __init usb3503_init(void)
{
int err;
err = i2c_register_driver(THIS_MODULE, &usb3503_i2c_driver);
if (err != 0)
pr_err("usb3503: Failed to register I2C driver: %d\n", err);
err = platform_driver_register(&usb3503_platform_driver);
if (err != 0)
pr_err("usb3503: Failed to register platform driver: %d\n",
err);
return 0;
}
module_init(usb3503_init);
static void __exit usb3503_exit(void)
{
platform_driver_unregister(&usb3503_platform_driver);
i2c_del_driver(&usb3503_i2c_driver);
}
module_exit(usb3503_exit);
MODULE_AUTHOR("Dongjin Kim <tobetter@gmail.com>");
MODULE_DESCRIPTION("USB3503 USB HUB driver");
MODULE_LICENSE("GPL");
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