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Subject[patch 2.6.29-rc3-git 2/2] USB: disable twl4030 USB regulators when cable unplugged
Date
From: Kalle Jokiniemi <kalle.jokiniemi@digia.com>

This patch disables LDO regulators VUSB1V5, VUSB1V8, and VUSB3V1
when the USB cable is unplugged, to eliminate that source of power
waste. (Enabled LDOs consume power at all times.)

Signed-off-by: Kalle Jokiniemi <kalle.jokiniemi@digia.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
---
Depends on the twl4030 regulator driver, so I'm suggesting this
be merged (with that driver) through the regulator patch queue
to simplify things.

drivers/usb/otg/twl4030-usb.c | 30 ++++++++++++++++++++++++------
1 file changed, 24 insertions(+), 6 deletions(-)

--- a/drivers/usb/otg/twl4030-usb.c
+++ b/drivers/usb/otg/twl4030-usb.c
@@ -34,6 +34,7 @@
#include <linux/delay.h>
#include <linux/usb/otg.h>
#include <linux/i2c/twl4030.h>
+#include <linux/regulator/consumer.h>


/* Register defines */
@@ -246,6 +247,11 @@ struct twl4030_usb {
struct otg_transceiver otg;
struct device *dev;

+ /* TWL4030 internal USB regulator supplies */
+ struct regulator *usb1v5;
+ struct regulator *usb1v8;
+ struct regulator *usb3v1;
+
/* for vbus reporting with irqs disabled */
spinlock_t lock;

@@ -434,6 +440,9 @@ static void twl4030_phy_power(struct twl

pwr = twl4030_usb_read(twl, PHY_PWR_CTRL);
if (on) {
+ regulator_enable(twl->usb1v5);
+ regulator_enable(twl->usb1v8);
+ regulator_enable(twl->usb3v1);
pwr &= ~PHY_PWR_PHYPWD;
WARN_ON(twl4030_usb_write_verify(twl, PHY_PWR_CTRL, pwr) < 0);
twl4030_usb_write(twl, PHY_CLK_CTRL,
@@ -443,6 +452,9 @@ static void twl4030_phy_power(struct twl
} else {
pwr |= PHY_PWR_PHYPWD;
WARN_ON(twl4030_usb_write_verify(twl, PHY_PWR_CTRL, pwr) < 0);
+ regulator_disable(twl->usb1v5);
+ regulator_disable(twl->usb1v8);
+ regulator_disable(twl->usb3v1);
}
}

@@ -480,16 +492,19 @@ static void twl4030_usb_ldo_init(struct
/* input to VUSB3V1 LDO is from VBAT, not VBUS */
twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0x14, VUSB_DEDICATED1);

- /* turn on 3.1V regulator */
- twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0x20, VUSB3V1_DEV_GRP);
+ /* Initialize 3.1V regulator */
+ twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0, VUSB3V1_DEV_GRP);
+ twl->usb3v1 = regulator_get(twl->dev, "usb3v1");
twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0, VUSB3V1_TYPE);

- /* turn on 1.5V regulator */
- twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0x20, VUSB1V5_DEV_GRP);
+ /* Initialize 1.5V regulator */
+ twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0, VUSB1V5_DEV_GRP);
+ twl->usb1v5 = regulator_get(twl->dev, "usb1v5");
twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0, VUSB1V5_TYPE);

- /* turn on 1.8V regulator */
- twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0x20, VUSB1V8_DEV_GRP);
+ /* Initialize 1.8V regulator */
+ twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0, VUSB1V8_DEV_GRP);
+ twl->usb1v8 = regulator_get(twl->dev, "usb1v8");
twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, 0, VUSB1V8_TYPE);

/* disable access to power configuration registers */
@@ -688,6 +703,9 @@ static int __exit twl4030_usb_remove(str
twl4030_usb_clear_bits(twl, POWER_CTRL, POWER_CTRL_OTG_ENAB);

twl4030_phy_power(twl, 0);
+ regulator_put(twl->usb1v5);
+ regulator_put(twl->usb1v8);
+ regulator_put(twl->usb3v1);

kfree(twl);


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