linux/drivers/usb/phy/phy-am335x-control.c
Daniel Mack a31a942a14 usb: phy: am335x-control: wait 1ms after power-up transitions
Tests have shown that when a power-up transition is followed by other
PHY operations too quickly, the USB port appears dead. Waiting 1ms fixes
this problem.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Cc: stable@vger.kernel.org [3.14]
Signed-off-by: Felipe Balbi <balbi@ti.com>
2014-04-21 10:21:24 -05:00

185 lines
4.2 KiB
C

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/io.h>
#include <linux/delay.h>
#include "am35x-phy-control.h"
struct am335x_control_usb {
struct device *dev;
void __iomem *phy_reg;
void __iomem *wkup;
spinlock_t lock;
struct phy_control phy_ctrl;
};
#define AM335X_USB0_CTRL 0x0
#define AM335X_USB1_CTRL 0x8
#define AM335x_USB_WKUP 0x0
#define USBPHY_CM_PWRDN (1 << 0)
#define USBPHY_OTG_PWRDN (1 << 1)
#define USBPHY_OTGVDET_EN (1 << 19)
#define USBPHY_OTGSESSEND_EN (1 << 20)
#define AM335X_PHY0_WK_EN (1 << 0)
#define AM335X_PHY1_WK_EN (1 << 8)
static void am335x_phy_wkup(struct phy_control *phy_ctrl, u32 id, bool on)
{
struct am335x_control_usb *usb_ctrl;
u32 val;
u32 reg;
usb_ctrl = container_of(phy_ctrl, struct am335x_control_usb, phy_ctrl);
switch (id) {
case 0:
reg = AM335X_PHY0_WK_EN;
break;
case 1:
reg = AM335X_PHY1_WK_EN;
break;
default:
WARN_ON(1);
return;
}
spin_lock(&usb_ctrl->lock);
val = readl(usb_ctrl->wkup);
if (on)
val |= reg;
else
val &= ~reg;
writel(val, usb_ctrl->wkup);
spin_unlock(&usb_ctrl->lock);
}
static void am335x_phy_power(struct phy_control *phy_ctrl, u32 id, bool on)
{
struct am335x_control_usb *usb_ctrl;
u32 val;
u32 reg;
usb_ctrl = container_of(phy_ctrl, struct am335x_control_usb, phy_ctrl);
switch (id) {
case 0:
reg = AM335X_USB0_CTRL;
break;
case 1:
reg = AM335X_USB1_CTRL;
break;
default:
WARN_ON(1);
return;
}
val = readl(usb_ctrl->phy_reg + reg);
if (on) {
val &= ~(USBPHY_CM_PWRDN | USBPHY_OTG_PWRDN);
val |= USBPHY_OTGVDET_EN | USBPHY_OTGSESSEND_EN;
} else {
val |= USBPHY_CM_PWRDN | USBPHY_OTG_PWRDN;
}
writel(val, usb_ctrl->phy_reg + reg);
/*
* Give the PHY ~1ms to complete the power up operation.
* Tests have shown unstable behaviour if other USB PHY related
* registers are written too shortly after such a transition.
*/
if (on)
mdelay(1);
}
static const struct phy_control ctrl_am335x = {
.phy_power = am335x_phy_power,
.phy_wkup = am335x_phy_wkup,
};
static const struct of_device_id omap_control_usb_id_table[] = {
{ .compatible = "ti,am335x-usb-ctrl-module", .data = &ctrl_am335x },
{}
};
MODULE_DEVICE_TABLE(of, omap_control_usb_id_table);
static struct platform_driver am335x_control_driver;
static int match(struct device *dev, void *data)
{
struct device_node *node = (struct device_node *)data;
return dev->of_node == node &&
dev->driver == &am335x_control_driver.driver;
}
struct phy_control *am335x_get_phy_control(struct device *dev)
{
struct device_node *node;
struct am335x_control_usb *ctrl_usb;
node = of_parse_phandle(dev->of_node, "ti,ctrl_mod", 0);
if (!node)
return NULL;
dev = bus_find_device(&platform_bus_type, NULL, node, match);
ctrl_usb = dev_get_drvdata(dev);
if (!ctrl_usb)
return NULL;
return &ctrl_usb->phy_ctrl;
}
EXPORT_SYMBOL_GPL(am335x_get_phy_control);
static int am335x_control_usb_probe(struct platform_device *pdev)
{
struct resource *res;
struct am335x_control_usb *ctrl_usb;
const struct of_device_id *of_id;
const struct phy_control *phy_ctrl;
of_id = of_match_node(omap_control_usb_id_table, pdev->dev.of_node);
if (!of_id)
return -EINVAL;
phy_ctrl = of_id->data;
ctrl_usb = devm_kzalloc(&pdev->dev, sizeof(*ctrl_usb), GFP_KERNEL);
if (!ctrl_usb) {
dev_err(&pdev->dev, "unable to alloc memory for control usb\n");
return -ENOMEM;
}
ctrl_usb->dev = &pdev->dev;
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "phy_ctrl");
ctrl_usb->phy_reg = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(ctrl_usb->phy_reg))
return PTR_ERR(ctrl_usb->phy_reg);
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "wakeup");
ctrl_usb->wkup = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(ctrl_usb->wkup))
return PTR_ERR(ctrl_usb->wkup);
spin_lock_init(&ctrl_usb->lock);
ctrl_usb->phy_ctrl = *phy_ctrl;
dev_set_drvdata(ctrl_usb->dev, ctrl_usb);
return 0;
}
static struct platform_driver am335x_control_driver = {
.probe = am335x_control_usb_probe,
.driver = {
.name = "am335x-control-usb",
.owner = THIS_MODULE,
.of_match_table = omap_control_usb_id_table,
},
};
module_platform_driver(am335x_control_driver);
MODULE_LICENSE("GPL v2");