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linux/drivers/usb/misc/usb3503.c
Stefan Agner b8626f1dc2 usb: misc: usb3503: make sure reset is low for at least 100us 
When using a GPIO which is high by default, and initialize the
driver in USB Hub mode, initialization fails with:
  [  111.757794] usb3503 0-0008: SP_ILOCK failed (-5)

The reason seems to be that the chip is not properly reset.
Probe does initialize reset low, however some lines later the
code already set it back high, which is not long enouth.

Make sure reset is asserted for at least 100us by inserting a
delay after initializing the reset pin during probe.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-11 18:39:52 +01:00

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// SPDX-License-Identifier: GPL-2.0+
/*
* Driver for SMSC USB3503 USB 2.0 hub controller driver
*
* Copyright (c) 2012-2013 Dongjin Kim (tobetter@gmail.com)
*/
#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;
u32 rate = 0;
hub->port_off_mask = 0;
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;
}
}
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)) {
hub->clk = clk;
if (rate != 0) {
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");
/* Datasheet defines a hardware reset to be at least 100us */
usleep_range(100, 10000);
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)
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_i2c_remove(struct i2c_client *i2c)
{
struct usb3503 *hub;
hub = i2c_get_clientdata(i2c);
if (hub->clk)
clk_disable_unprepare(hub->clk);
return 0;
}
static int usb3503_platform_probe(struct platform_device *pdev)
{
struct usb3503 *hub;
hub = devm_kzalloc(&pdev->dev, sizeof(struct usb3503), GFP_KERNEL);
if (!hub)
return -ENOMEM;
hub->dev = &pdev->dev;
platform_set_drvdata(pdev, hub);
return usb3503_probe(hub);
}
static int usb3503_platform_remove(struct platform_device *pdev)
{
struct usb3503 *hub;
hub = platform_get_drvdata(pdev);
if (hub->clk)
clk_disable_unprepare(hub->clk);
return 0;
}
#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,
.remove = usb3503_i2c_remove,
.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),
},
.probe = usb3503_platform_probe,
.remove = usb3503_platform_remove,
};
static int __init usb3503_init(void)
{
int err;
err = i2c_add_driver(&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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