alistair23-linux/drivers/regulator/twl-regulator.c
Douglas Anderson 02f3703934
regulator: Don't return or expect -errno from of_map_mode()
In of_get_regulation_constraints() we were taking the result of
of_map_mode() (an unsigned int) and assigning it to an int.  We were
then checking whether this value was -EINVAL.  Some implementers of
of_map_mode() were returning -EINVAL (even though the return type of
their function needed to be unsigned int) because they needed to
signal an error back to of_get_regulation_constraints().

In general in the regulator framework the mode is always referred to
as an unsigned int.  While we could fix this to be a signed int (the
highest value we store in there right now is 0x8), it's actually
pretty clean to just define the regulator mode 0x0 (the lack of any
bits set) as an invalid mode.  Let's do that.

Fixes: 5e5e3a42c6 ("regulator: of: Add support for parsing initial and suspend modes")
Suggested-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-04-20 12:45:36 +01:00

675 lines
18 KiB
C

/*
* twl-regulator.c -- support regulators in twl4030/twl6030 family chips
*
* Copyright (C) 2008 David Brownell
*
* 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.
*/
#include <linux/module.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/of_regulator.h>
#include <linux/mfd/twl.h>
#include <linux/delay.h>
/*
* The TWL4030/TW5030/TPS659x0 family chips include power management, a
* USB OTG transceiver, an RTC, ADC, PWM, and lots more. Some versions
* include an audio codec, battery charger, and more voltage regulators.
* These chips are often used in OMAP-based systems.
*
* This driver implements software-based resource control for various
* voltage regulators. This is usually augmented with state machine
* based control.
*/
struct twlreg_info {
/* start of regulator's PM_RECEIVER control register bank */
u8 base;
/* twl resource ID, for resource control state machine */
u8 id;
/* voltage in mV = table[VSEL]; table_len must be a power-of-two */
u8 table_len;
const u16 *table;
/* State REMAP default configuration */
u8 remap;
/* used by regulator core */
struct regulator_desc desc;
/* chip specific features */
unsigned long features;
/* data passed from board for external get/set voltage */
void *data;
};
/* LDO control registers ... offset is from the base of its register bank.
* The first three registers of all power resource banks help hardware to
* manage the various resource groups.
*/
/* Common offset in TWL4030/6030 */
#define VREG_GRP 0
/* TWL4030 register offsets */
#define VREG_TYPE 1
#define VREG_REMAP 2
#define VREG_DEDICATED 3 /* LDO control */
#define VREG_VOLTAGE_SMPS_4030 9
/* TWL6030 register offsets */
#define VREG_TRANS 1
#define VREG_STATE 2
#define VREG_VOLTAGE 3
#define VREG_VOLTAGE_SMPS 4
static inline int
twlreg_read(struct twlreg_info *info, unsigned slave_subgp, unsigned offset)
{
u8 value;
int status;
status = twl_i2c_read_u8(slave_subgp,
&value, info->base + offset);
return (status < 0) ? status : value;
}
static inline int
twlreg_write(struct twlreg_info *info, unsigned slave_subgp, unsigned offset,
u8 value)
{
return twl_i2c_write_u8(slave_subgp,
value, info->base + offset);
}
/*----------------------------------------------------------------------*/
/* generic power resource operations, which work on all regulators */
static int twlreg_grp(struct regulator_dev *rdev)
{
return twlreg_read(rdev_get_drvdata(rdev), TWL_MODULE_PM_RECEIVER,
VREG_GRP);
}
/*
* Enable/disable regulators by joining/leaving the P1 (processor) group.
* We assume nobody else is updating the DEV_GRP registers.
*/
/* definition for 4030 family */
#define P3_GRP_4030 BIT(7) /* "peripherals" */
#define P2_GRP_4030 BIT(6) /* secondary processor, modem, etc */
#define P1_GRP_4030 BIT(5) /* CPU/Linux */
/* definition for 6030 family */
#define P3_GRP_6030 BIT(2) /* secondary processor, modem, etc */
#define P2_GRP_6030 BIT(1) /* "peripherals" */
#define P1_GRP_6030 BIT(0) /* CPU/Linux */
static int twl4030reg_is_enabled(struct regulator_dev *rdev)
{
int state = twlreg_grp(rdev);
if (state < 0)
return state;
return state & P1_GRP_4030;
}
#define PB_I2C_BUSY BIT(0)
#define PB_I2C_BWEN BIT(1)
/* Wait until buffer empty/ready to send a word on power bus. */
static int twl4030_wait_pb_ready(void)
{
int ret;
int timeout = 10;
u8 val;
do {
ret = twl_i2c_read_u8(TWL_MODULE_PM_MASTER, &val,
TWL4030_PM_MASTER_PB_CFG);
if (ret < 0)
return ret;
if (!(val & PB_I2C_BUSY))
return 0;
mdelay(1);
timeout--;
} while (timeout);
return -ETIMEDOUT;
}
/* Send a word over the powerbus */
static int twl4030_send_pb_msg(unsigned msg)
{
u8 val;
int ret;
/* save powerbus configuration */
ret = twl_i2c_read_u8(TWL_MODULE_PM_MASTER, &val,
TWL4030_PM_MASTER_PB_CFG);
if (ret < 0)
return ret;
/* Enable i2c access to powerbus */
ret = twl_i2c_write_u8(TWL_MODULE_PM_MASTER, val | PB_I2C_BWEN,
TWL4030_PM_MASTER_PB_CFG);
if (ret < 0)
return ret;
ret = twl4030_wait_pb_ready();
if (ret < 0)
return ret;
ret = twl_i2c_write_u8(TWL_MODULE_PM_MASTER, msg >> 8,
TWL4030_PM_MASTER_PB_WORD_MSB);
if (ret < 0)
return ret;
ret = twl_i2c_write_u8(TWL_MODULE_PM_MASTER, msg & 0xff,
TWL4030_PM_MASTER_PB_WORD_LSB);
if (ret < 0)
return ret;
ret = twl4030_wait_pb_ready();
if (ret < 0)
return ret;
/* Restore powerbus configuration */
return twl_i2c_write_u8(TWL_MODULE_PM_MASTER, val,
TWL4030_PM_MASTER_PB_CFG);
}
static int twl4030reg_enable(struct regulator_dev *rdev)
{
struct twlreg_info *info = rdev_get_drvdata(rdev);
int grp;
int ret;
grp = twlreg_grp(rdev);
if (grp < 0)
return grp;
grp |= P1_GRP_4030;
ret = twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_GRP, grp);
return ret;
}
static int twl4030reg_disable(struct regulator_dev *rdev)
{
struct twlreg_info *info = rdev_get_drvdata(rdev);
int grp;
int ret;
grp = twlreg_grp(rdev);
if (grp < 0)
return grp;
grp &= ~(P1_GRP_4030 | P2_GRP_4030 | P3_GRP_4030);
ret = twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_GRP, grp);
return ret;
}
static int twl4030reg_get_status(struct regulator_dev *rdev)
{
int state = twlreg_grp(rdev);
if (state < 0)
return state;
state &= 0x0f;
/* assume state != WARM_RESET; we'd not be running... */
if (!state)
return REGULATOR_STATUS_OFF;
return (state & BIT(3))
? REGULATOR_STATUS_NORMAL
: REGULATOR_STATUS_STANDBY;
}
static int twl4030reg_set_mode(struct regulator_dev *rdev, unsigned mode)
{
struct twlreg_info *info = rdev_get_drvdata(rdev);
unsigned message;
/* We can only set the mode through state machine commands... */
switch (mode) {
case REGULATOR_MODE_NORMAL:
message = MSG_SINGULAR(DEV_GRP_P1, info->id, RES_STATE_ACTIVE);
break;
case REGULATOR_MODE_STANDBY:
message = MSG_SINGULAR(DEV_GRP_P1, info->id, RES_STATE_SLEEP);
break;
default:
return -EINVAL;
}
return twl4030_send_pb_msg(message);
}
static inline unsigned int twl4030reg_map_mode(unsigned int mode)
{
switch (mode) {
case RES_STATE_ACTIVE:
return REGULATOR_MODE_NORMAL;
case RES_STATE_SLEEP:
return REGULATOR_MODE_STANDBY;
default:
return REGULATOR_MODE_INVALID;
}
}
/*----------------------------------------------------------------------*/
/*
* Support for adjustable-voltage LDOs uses a four bit (or less) voltage
* select field in its control register. We use tables indexed by VSEL
* to record voltages in milliVolts. (Accuracy is about three percent.)
*
* Note that VSEL values for VAUX2 changed in twl5030 and newer silicon;
* currently handled by listing two slightly different VAUX2 regulators,
* only one of which will be configured.
*
* VSEL values documented as "TI cannot support these values" are flagged
* in these tables as UNSUP() values; we normally won't assign them.
*
* VAUX3 at 3V is incorrectly listed in some TI manuals as unsupported.
* TI are revising the twl5030/tps659x0 specs to support that 3.0V setting.
*/
#define UNSUP_MASK 0x8000
#define UNSUP(x) (UNSUP_MASK | (x))
#define IS_UNSUP(info, x) \
((UNSUP_MASK & (x)) && \
!((info)->features & TWL4030_ALLOW_UNSUPPORTED))
#define LDO_MV(x) (~UNSUP_MASK & (x))
static const u16 VAUX1_VSEL_table[] = {
UNSUP(1500), UNSUP(1800), 2500, 2800,
3000, 3000, 3000, 3000,
};
static const u16 VAUX2_4030_VSEL_table[] = {
UNSUP(1000), UNSUP(1000), UNSUP(1200), 1300,
1500, 1800, UNSUP(1850), 2500,
UNSUP(2600), 2800, UNSUP(2850), UNSUP(3000),
UNSUP(3150), UNSUP(3150), UNSUP(3150), UNSUP(3150),
};
static const u16 VAUX2_VSEL_table[] = {
1700, 1700, 1900, 1300,
1500, 1800, 2000, 2500,
2100, 2800, 2200, 2300,
2400, 2400, 2400, 2400,
};
static const u16 VAUX3_VSEL_table[] = {
1500, 1800, 2500, 2800,
3000, 3000, 3000, 3000,
};
static const u16 VAUX4_VSEL_table[] = {
700, 1000, 1200, UNSUP(1300),
1500, 1800, UNSUP(1850), 2500,
UNSUP(2600), 2800, UNSUP(2850), UNSUP(3000),
UNSUP(3150), UNSUP(3150), UNSUP(3150), UNSUP(3150),
};
static const u16 VMMC1_VSEL_table[] = {
1850, 2850, 3000, 3150,
};
static const u16 VMMC2_VSEL_table[] = {
UNSUP(1000), UNSUP(1000), UNSUP(1200), UNSUP(1300),
UNSUP(1500), UNSUP(1800), 1850, UNSUP(2500),
2600, 2800, 2850, 3000,
3150, 3150, 3150, 3150,
};
static const u16 VPLL1_VSEL_table[] = {
1000, 1200, 1300, 1800,
UNSUP(2800), UNSUP(3000), UNSUP(3000), UNSUP(3000),
};
static const u16 VPLL2_VSEL_table[] = {
700, 1000, 1200, 1300,
UNSUP(1500), 1800, UNSUP(1850), UNSUP(2500),
UNSUP(2600), UNSUP(2800), UNSUP(2850), UNSUP(3000),
UNSUP(3150), UNSUP(3150), UNSUP(3150), UNSUP(3150),
};
static const u16 VSIM_VSEL_table[] = {
UNSUP(1000), UNSUP(1200), UNSUP(1300), 1800,
2800, 3000, 3000, 3000,
};
static const u16 VDAC_VSEL_table[] = {
1200, 1300, 1800, 1800,
};
static const u16 VIO_VSEL_table[] = {
1800, 1850,
};
static const u16 VINTANA2_VSEL_table[] = {
2500, 2750,
};
static int twl4030ldo_list_voltage(struct regulator_dev *rdev, unsigned index)
{
struct twlreg_info *info = rdev_get_drvdata(rdev);
int mV = info->table[index];
return IS_UNSUP(info, mV) ? 0 : (LDO_MV(mV) * 1000);
}
static int
twl4030ldo_set_voltage_sel(struct regulator_dev *rdev, unsigned selector)
{
struct twlreg_info *info = rdev_get_drvdata(rdev);
return twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_VOLTAGE,
selector);
}
static int twl4030ldo_get_voltage_sel(struct regulator_dev *rdev)
{
struct twlreg_info *info = rdev_get_drvdata(rdev);
int vsel = twlreg_read(info, TWL_MODULE_PM_RECEIVER, VREG_VOLTAGE);
if (vsel < 0)
return vsel;
vsel &= info->table_len - 1;
return vsel;
}
static struct regulator_ops twl4030ldo_ops = {
.list_voltage = twl4030ldo_list_voltage,
.set_voltage_sel = twl4030ldo_set_voltage_sel,
.get_voltage_sel = twl4030ldo_get_voltage_sel,
.enable = twl4030reg_enable,
.disable = twl4030reg_disable,
.is_enabled = twl4030reg_is_enabled,
.set_mode = twl4030reg_set_mode,
.get_status = twl4030reg_get_status,
};
static int
twl4030smps_set_voltage(struct regulator_dev *rdev, int min_uV, int max_uV,
unsigned *selector)
{
struct twlreg_info *info = rdev_get_drvdata(rdev);
int vsel = DIV_ROUND_UP(min_uV - 600000, 12500);
twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_VOLTAGE_SMPS_4030, vsel);
return 0;
}
static int twl4030smps_get_voltage(struct regulator_dev *rdev)
{
struct twlreg_info *info = rdev_get_drvdata(rdev);
int vsel;
vsel = twlreg_read(info, TWL_MODULE_PM_RECEIVER,
VREG_VOLTAGE_SMPS_4030);
return vsel * 12500 + 600000;
}
static struct regulator_ops twl4030smps_ops = {
.set_voltage = twl4030smps_set_voltage,
.get_voltage = twl4030smps_get_voltage,
};
/*----------------------------------------------------------------------*/
static struct regulator_ops twl4030fixed_ops = {
.list_voltage = regulator_list_voltage_linear,
.enable = twl4030reg_enable,
.disable = twl4030reg_disable,
.is_enabled = twl4030reg_is_enabled,
.set_mode = twl4030reg_set_mode,
.get_status = twl4030reg_get_status,
};
/*----------------------------------------------------------------------*/
#define TWL4030_ADJUSTABLE_LDO(label, offset, num, turnon_delay, remap_conf) \
static const struct twlreg_info TWL4030_INFO_##label = { \
.base = offset, \
.id = num, \
.table_len = ARRAY_SIZE(label##_VSEL_table), \
.table = label##_VSEL_table, \
.remap = remap_conf, \
.desc = { \
.name = #label, \
.id = TWL4030_REG_##label, \
.n_voltages = ARRAY_SIZE(label##_VSEL_table), \
.ops = &twl4030ldo_ops, \
.type = REGULATOR_VOLTAGE, \
.owner = THIS_MODULE, \
.enable_time = turnon_delay, \
.of_map_mode = twl4030reg_map_mode, \
}, \
}
#define TWL4030_ADJUSTABLE_SMPS(label, offset, num, turnon_delay, remap_conf) \
static const struct twlreg_info TWL4030_INFO_##label = { \
.base = offset, \
.id = num, \
.remap = remap_conf, \
.desc = { \
.name = #label, \
.id = TWL4030_REG_##label, \
.ops = &twl4030smps_ops, \
.type = REGULATOR_VOLTAGE, \
.owner = THIS_MODULE, \
.enable_time = turnon_delay, \
.of_map_mode = twl4030reg_map_mode, \
}, \
}
#define TWL4030_FIXED_LDO(label, offset, mVolts, num, turnon_delay, \
remap_conf) \
static const struct twlreg_info TWLFIXED_INFO_##label = { \
.base = offset, \
.id = num, \
.remap = remap_conf, \
.desc = { \
.name = #label, \
.id = TWL4030##_REG_##label, \
.n_voltages = 1, \
.ops = &twl4030fixed_ops, \
.type = REGULATOR_VOLTAGE, \
.owner = THIS_MODULE, \
.min_uV = mVolts * 1000, \
.enable_time = turnon_delay, \
.of_map_mode = twl4030reg_map_mode, \
}, \
}
/*
* We list regulators here if systems need some level of
* software control over them after boot.
*/
TWL4030_ADJUSTABLE_LDO(VAUX1, 0x17, 1, 100, 0x08);
TWL4030_ADJUSTABLE_LDO(VAUX2_4030, 0x1b, 2, 100, 0x08);
TWL4030_ADJUSTABLE_LDO(VAUX2, 0x1b, 2, 100, 0x08);
TWL4030_ADJUSTABLE_LDO(VAUX3, 0x1f, 3, 100, 0x08);
TWL4030_ADJUSTABLE_LDO(VAUX4, 0x23, 4, 100, 0x08);
TWL4030_ADJUSTABLE_LDO(VMMC1, 0x27, 5, 100, 0x08);
TWL4030_ADJUSTABLE_LDO(VMMC2, 0x2b, 6, 100, 0x08);
TWL4030_ADJUSTABLE_LDO(VPLL1, 0x2f, 7, 100, 0x00);
TWL4030_ADJUSTABLE_LDO(VPLL2, 0x33, 8, 100, 0x08);
TWL4030_ADJUSTABLE_LDO(VSIM, 0x37, 9, 100, 0x00);
TWL4030_ADJUSTABLE_LDO(VDAC, 0x3b, 10, 100, 0x08);
TWL4030_ADJUSTABLE_LDO(VINTANA2, 0x43, 12, 100, 0x08);
TWL4030_ADJUSTABLE_LDO(VIO, 0x4b, 14, 1000, 0x08);
TWL4030_ADJUSTABLE_SMPS(VDD1, 0x55, 15, 1000, 0x08);
TWL4030_ADJUSTABLE_SMPS(VDD2, 0x63, 16, 1000, 0x08);
/* VUSBCP is managed *only* by the USB subchip */
TWL4030_FIXED_LDO(VINTANA1, 0x3f, 1500, 11, 100, 0x08);
TWL4030_FIXED_LDO(VINTDIG, 0x47, 1500, 13, 100, 0x08);
TWL4030_FIXED_LDO(VUSB1V5, 0x71, 1500, 17, 100, 0x08);
TWL4030_FIXED_LDO(VUSB1V8, 0x74, 1800, 18, 100, 0x08);
TWL4030_FIXED_LDO(VUSB3V1, 0x77, 3100, 19, 150, 0x08);
#define TWL_OF_MATCH(comp, family, label) \
{ \
.compatible = comp, \
.data = &family##_INFO_##label, \
}
#define TWL4030_OF_MATCH(comp, label) TWL_OF_MATCH(comp, TWL4030, label)
#define TWL6030_OF_MATCH(comp, label) TWL_OF_MATCH(comp, TWL6030, label)
#define TWL6032_OF_MATCH(comp, label) TWL_OF_MATCH(comp, TWL6032, label)
#define TWLFIXED_OF_MATCH(comp, label) TWL_OF_MATCH(comp, TWLFIXED, label)
#define TWLSMPS_OF_MATCH(comp, label) TWL_OF_MATCH(comp, TWLSMPS, label)
static const struct of_device_id twl_of_match[] = {
TWL4030_OF_MATCH("ti,twl4030-vaux1", VAUX1),
TWL4030_OF_MATCH("ti,twl4030-vaux2", VAUX2_4030),
TWL4030_OF_MATCH("ti,twl5030-vaux2", VAUX2),
TWL4030_OF_MATCH("ti,twl4030-vaux3", VAUX3),
TWL4030_OF_MATCH("ti,twl4030-vaux4", VAUX4),
TWL4030_OF_MATCH("ti,twl4030-vmmc1", VMMC1),
TWL4030_OF_MATCH("ti,twl4030-vmmc2", VMMC2),
TWL4030_OF_MATCH("ti,twl4030-vpll1", VPLL1),
TWL4030_OF_MATCH("ti,twl4030-vpll2", VPLL2),
TWL4030_OF_MATCH("ti,twl4030-vsim", VSIM),
TWL4030_OF_MATCH("ti,twl4030-vdac", VDAC),
TWL4030_OF_MATCH("ti,twl4030-vintana2", VINTANA2),
TWL4030_OF_MATCH("ti,twl4030-vio", VIO),
TWL4030_OF_MATCH("ti,twl4030-vdd1", VDD1),
TWL4030_OF_MATCH("ti,twl4030-vdd2", VDD2),
TWLFIXED_OF_MATCH("ti,twl4030-vintana1", VINTANA1),
TWLFIXED_OF_MATCH("ti,twl4030-vintdig", VINTDIG),
TWLFIXED_OF_MATCH("ti,twl4030-vusb1v5", VUSB1V5),
TWLFIXED_OF_MATCH("ti,twl4030-vusb1v8", VUSB1V8),
TWLFIXED_OF_MATCH("ti,twl4030-vusb3v1", VUSB3V1),
{},
};
MODULE_DEVICE_TABLE(of, twl_of_match);
static int twlreg_probe(struct platform_device *pdev)
{
int id;
struct twlreg_info *info;
const struct twlreg_info *template;
struct regulator_init_data *initdata;
struct regulation_constraints *c;
struct regulator_dev *rdev;
const struct of_device_id *match;
struct regulator_config config = { };
match = of_match_device(twl_of_match, &pdev->dev);
if (!match)
return -ENODEV;
template = match->data;
if (!template)
return -ENODEV;
id = template->desc.id;
initdata = of_get_regulator_init_data(&pdev->dev, pdev->dev.of_node,
&template->desc);
if (!initdata)
return -EINVAL;
info = devm_kmemdup(&pdev->dev, template, sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;
/* Constrain board-specific capabilities according to what
* this driver and the chip itself can actually do.
*/
c = &initdata->constraints;
c->valid_modes_mask &= REGULATOR_MODE_NORMAL | REGULATOR_MODE_STANDBY;
c->valid_ops_mask &= REGULATOR_CHANGE_VOLTAGE
| REGULATOR_CHANGE_MODE
| REGULATOR_CHANGE_STATUS;
switch (id) {
case TWL4030_REG_VIO:
case TWL4030_REG_VDD1:
case TWL4030_REG_VDD2:
case TWL4030_REG_VPLL1:
case TWL4030_REG_VINTANA1:
case TWL4030_REG_VINTANA2:
case TWL4030_REG_VINTDIG:
c->always_on = true;
break;
default:
break;
}
config.dev = &pdev->dev;
config.init_data = initdata;
config.driver_data = info;
config.of_node = pdev->dev.of_node;
rdev = devm_regulator_register(&pdev->dev, &info->desc, &config);
if (IS_ERR(rdev)) {
dev_err(&pdev->dev, "can't register %s, %ld\n",
info->desc.name, PTR_ERR(rdev));
return PTR_ERR(rdev);
}
platform_set_drvdata(pdev, rdev);
twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_REMAP, info->remap);
/* NOTE: many regulators support short-circuit IRQs (presentable
* as REGULATOR_OVER_CURRENT notifications?) configured via:
* - SC_CONFIG
* - SC_DETECT1 (vintana2, vmmc1/2, vaux1/2/3/4)
* - SC_DETECT2 (vusb, vdac, vio, vdd1/2, vpll2)
* - IT_CONFIG
*/
return 0;
}
MODULE_ALIAS("platform:twl4030_reg");
static struct platform_driver twlreg_driver = {
.probe = twlreg_probe,
/* NOTE: short name, to work around driver model truncation of
* "twl_regulator.12" (and friends) to "twl_regulator.1".
*/
.driver = {
.name = "twl4030_reg",
.of_match_table = of_match_ptr(twl_of_match),
},
};
static int __init twlreg_init(void)
{
return platform_driver_register(&twlreg_driver);
}
subsys_initcall(twlreg_init);
static void __exit twlreg_exit(void)
{
platform_driver_unregister(&twlreg_driver);
}
module_exit(twlreg_exit)
MODULE_DESCRIPTION("TWL4030 regulator driver");
MODULE_LICENSE("GPL");