/*
* drivers/regulator/ab3100.c
*
* Copyright (C) 2008-2009 ST-Ericsson AB
* License terms: GNU General Public License (GPL) version 2
* Low-level control of the AB3100 IC Low Dropout (LDO)
* regulators, external regulator and buck converter
* Author: Mattias Wallin <mattias.wallin@stericsson.com>
* Author: Linus Walleij <linus.walleij@stericsson.com>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/mfd/ab3100.h>
/* LDO registers and some handy masking definitions for AB3100 */
#define AB3100_LDO_A 0x40
#define AB3100_LDO_C 0x41
#define AB3100_LDO_D 0x42
#define AB3100_LDO_E 0x43
#define AB3100_LDO_E_SLEEP 0x44
#define AB3100_LDO_F 0x45
#define AB3100_LDO_G 0x46
#define AB3100_LDO_H 0x47
#define AB3100_LDO_H_SLEEP_MODE 0
#define AB3100_LDO_H_SLEEP_EN 2
#define AB3100_LDO_ON 4
#define AB3100_LDO_H_VSEL_AC 5
#define AB3100_LDO_K 0x48
#define AB3100_LDO_EXT 0x49
#define AB3100_BUCK 0x4A
#define AB3100_BUCK_SLEEP 0x4B
#define AB3100_REG_ON_MASK 0x10
/**
* struct ab3100_regulator
* A struct passed around the individual regulator functions
* @platform_device: platform device holding this regulator
* @ab3100: handle to the AB3100 parent chip
* @plfdata: AB3100 platform data passed in at probe time
* @regreg: regulator register number in the AB3100
* @fixed_voltage: a fixed voltage for this regulator, if this
* 0 the voltages array is used instead.
* @typ_voltages: an array of available typical voltages for
* this regulator
* @voltages_len: length of the array of available voltages
*/
struct ab3100_regulator {
struct regulator_dev *rdev;
struct ab3100 *ab3100;
struct ab3100_platform_data *plfdata;
u8 regreg;
int fixed_voltage;
int const *typ_voltages;
u8 voltages_len;
};
/* The order in which registers are initialized */
static const u8 ab3100_reg_init_order[AB3100_NUM_REGULATORS+2] = {
AB3100_LDO_A,
AB3100_LDO_C,
AB3100_LDO_E,
AB3100_LDO_E_SLEEP,
AB3100_LDO_F,
AB3100_LDO_G,
AB3100_LDO_H,
AB3100_LDO_K,
AB3100_LDO_EXT,
AB3100_BUCK,
AB3100_BUCK_SLEEP,
AB3100_LDO_D,
};
/* Preset (hardware defined) voltages for these regulators */
#define LDO_A_VOLTAGE 2750000
#define LDO_C_VOLTAGE 2650000
#define LDO_D_VOLTAGE 2650000
static const int const ldo_e_buck_typ_voltages[] = {
1800000,
1400000,
1300000,
1200000,
1100000,
1050000,
900000,
};
static const int const ldo_f_typ_voltages[] = {
1800000,
1400000,
1300000,
1200000,
1100000,
1050000,
2500000,
2650000,
};
static const int const ldo_g_typ_voltages[] = {
2850000,
2750000,
1800000,
1500000,
};
static const int const ldo_h_typ_voltages[] = {
2750000,
1800000,
1500000,
1200000,
};
static const int const ldo_k_typ_voltages[] = {
2750000,
1800000,
};
/* The regulator devices */
static struct ab3100_regulator
ab3100_regulators[AB3100_NUM_REGULATORS] = {
{
.regreg = AB3100_LDO_A,
.fixed_voltage = LDO_A_VOLTAGE,
},
{
.regreg = AB3100_LDO_C,
.fixed_voltage = LDO_C_VOLTAGE,
},
{
.regreg = AB3100_LDO_D,
.fixed_voltage = LDO_D_VOLTAGE,
},
{
.regreg = AB3100_LDO_E,
.typ_voltages = ldo_e_buck_typ_voltages,
.voltages_len = ARRAY_SIZE(ldo_e_buck_typ_voltages),
},
{
.regreg = AB3100_LDO_F,
.typ_voltages = ldo_f_typ_voltages,
.voltages_len = ARRAY_SIZE(ldo_f_typ_voltages),
},
{
.regreg = AB3100_LDO_G,
.typ_voltages = ldo_g_typ_voltages,
.voltages_len = ARRAY_SIZE(ldo_g_typ_voltages),
},
{
.regreg = AB3100_LDO_H,
.typ_voltages = ldo_h_typ_voltages,
.voltages_len = ARRAY_SIZE(ldo_h_typ_voltages),
},
{
.regreg = AB3100_LDO_K,
.typ_voltages = ldo_k_typ_voltages,
.voltages_len = ARRAY_SIZE(ldo_k_typ_voltages),
},
{
.regreg = AB3100_LDO_EXT,
/* No voltages for the external regulator */
},
{
.regreg = AB3100_BUCK,
.typ_voltages = ldo_e_buck_typ_voltages,
.voltages_len = ARRAY_SIZE(ldo_e_buck_typ_voltages),
},
};
/*
* General functions for enable, disable and is_enabled used for
* LDO: A,C,E,F,G,H,K,EXT and BUCK
*/
static int ab3100_enable_regulator(struct regulator_dev *reg)
{
struct ab3100_regulator *abreg = reg->reg_data;
int err;
u8 regval;
err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg,
®val);
if (err) {
dev_warn(®->dev, "failed to get regid %d value\n",
abreg->regreg);
return err;
}
/* The regulator is already on, no reason to go further */
if (regval & AB3100_REG_ON_MASK)
return 0;
regval |= AB3100_REG_ON_MASK;
err = ab3100_set_register_interruptible(abreg->ab3100, abreg->regreg,
regval);
if (err) {
dev_warn(®->dev, "failed to set regid %d value\n",
abreg->regreg);
return err;
}
/* Per-regulator power on delay from spec */
switch (abreg->regreg) {
case AB3100_LDO_A: /* Fallthrough */
case AB3100_LDO_C: /* Fallthrough */
case AB3100_LDO_D: /* Fallthrough */
case AB3100_LDO_E: /* Fallthrough */
case AB3100_LDO_H: /* Fallthrough */
case AB3100_LDO_K:
udelay(200);
break;
case AB3100_LDO_F:
udelay(600);
break;
case AB3100_LDO_G:
udelay(400);
break;
case AB3100_BUCK:
mdelay(1);
break;
default:
break;
}
return 0;
}
static int ab3100_disable_regulator(struct regulator_dev *reg)
{
struct ab3100_regulator *abreg = reg->reg_data;
int err;
u8 regval;
/*
* LDO D is a special regulator. When it is disabled, the entire
* system is shut down. So this is handled specially.
*/
if (abreg->regreg == AB3100_LDO_D) {
int i;
dev_info(®->dev, "disabling LDO D - shut down system\n");
/*
* Set regulators to default values, ignore any errors,
* we're going DOWN
*/
for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) {
(void) ab3100_set_register_interruptible(abreg->ab3100,
ab3100_reg_init_order[i],
abreg->plfdata->reg_initvals[i]);
}
/* Setting LDO D to 0x00 cuts the power to the SoC */
return ab3100_set_register_interruptible(abreg->ab3100,
AB3100_LDO_D, 0x00U);
}
/*
* All other regulators are handled here
*/
err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg,
®val);
if (err) {
dev_err(®->dev, "unable to get register 0x%x\n",
abreg->regreg);
return err;
}
regval &= ~AB3100_REG_ON_MASK;
return ab3100_set_register_interruptible(abreg->ab3100, abreg->regreg,
regval);
}
static int ab3100_is_enabled_regulator(struct regulator_dev *reg)
{
struct ab3100_regulator *abreg = reg->reg_data;
u8 regval;
int err;
err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg,
®val);
if (err) {
dev_err(®->dev, "unable to get register 0x%x\n",
abreg->regreg);
return err;
}
return regval & AB3100_REG_ON_MASK;
}
static int ab3100_list_voltage_regulator(struct regulator_dev *reg,
unsigned selector)
{
struct ab3100_regulator *abreg = reg->reg_data;
if (selector > abreg->voltages_len)
return -EINVAL;
return abreg->typ_voltages[selector];
}
static int ab3100_get_voltage_regulator(struct regulator_dev *reg)
{
struct ab3100_regulator *abreg = reg->reg_data;
u8 regval;
int err;
/* Return the voltage for fixed regulators immediately */
if (abreg->fixed_voltage)
return abreg->fixed_voltage;
/*
* For variable types, read out setting and index into
* supplied voltage list.
*/
err = ab3100_get_register_interruptible(abreg->ab3100,
abreg->regreg, ®val);
if (err) {
dev_warn(®->dev,
"failed to get regulator value in register %02x\n",
abreg->regreg);
return err;
}
/* The 3 highest bits index voltages */
regval &= 0xE0;
regval >>= 5;
if (regval > abreg->voltages_len) {
dev_err(®->dev,
"regulator register %02x contains an illegal voltage setting\n",
abreg->regreg);
return -EINVAL;
}
return abreg->typ_voltages[regval];
}
static int ab3100_get_best_voltage_index(struct regulator_dev *reg,
int min_uV, int max_uV)
{
struct ab3100_regulator *abreg = reg->reg_data;
int i;
int bestmatch;
int bestindex;
/*
* Locate the minimum voltage fitting the criteria on
* this regulator. The switchable voltages are not
* in strict falling order so we need to check them
* all for the best match.
*/
bestmatch = INT_MAX;
bestindex = -1;
for (i = 0; i < abreg->voltages_len; i++) {
if (abreg->typ_voltages[i] <= max_uV &&
abreg->typ_voltages[i] >= min_uV &&
abreg->typ_voltages[i] < bestmatch) {
bestmatch = abreg->typ_voltages[i];
bestindex = i;
}
}
if (bestindex < 0) {
dev_warn(®->dev, "requested %d<=x<=%d uV, out of range!\n",
min_uV, max_uV);
return -EINVAL;
}
return bestindex;
}
static int ab3100_set_voltage_regulator(struct regulator_dev *reg,
int min_uV, int max_uV)
{
struct ab3100_regulator *abreg = reg->reg_data;
u8 regval;
int err;
int bestindex;
bestindex = ab3100_get_best_voltage_index(reg, min_uV, max_uV);
if (bestindex < 0)
return bestindex;
err = ab3100_get_register_interruptible(abreg->ab3100,
abreg->regreg, ®val);
if (err) {
dev_warn(®->dev,
"failed to get regulator register %02x\n",
abreg->regreg);
return err;
}
/* The highest three bits control the variable regulators */
regval &= ~0xE0;
regval |= (bestindex << 5);
err = ab3100_set_register_interruptible(abreg->ab3100,
abreg->regreg, regval);
if (err)
dev_warn(®->dev, "failed to set regulator register %02x\n",
abreg->regreg);
return err;
}
static int ab3100_set_suspend_voltage_regulator(struct regulator_dev *reg,
int uV)
{
struct ab3100_regulator *abreg = reg->reg_data;
u8 regval;
int err;
int bestindex;
u8 targetreg;
if (abreg->regreg == AB3100_LDO_E)
targetreg = AB3100_LDO_E_SLEEP;
else if (abreg->regreg == AB3100_BUCK)
targetreg = AB3100_BUCK_SLEEP;
else
return -EINVAL;
/* LDO E and BUCK have special suspend voltages you can set */
bestindex = ab3100_get_best_voltage_index(reg, uV, uV);
err = ab3100_get_register_interruptible(abreg->ab3100,
targetreg, ®val);
if (err) {
dev_warn(®->dev,
"failed to get regulator register %02x\n",
targetreg);
return err;
}
/* The highest three bits control the variable regulators */
regval &= ~0xE0;
regval |= (bestindex << 5);
err = ab3100_set_register_interruptible(abreg->ab3100,
targetreg, regval);
if (err)
dev_warn(®->dev, "failed to set regulator register %02x\n",
abreg->regreg);
return err;
}
/*
* The external regulator can just define a fixed voltage.
*/
static int ab3100_get_voltage_regulator_external(struct regulator_dev *reg)
{
struct ab3100_regulator *abreg = reg->reg_data;
return abreg->plfdata->external_voltage;
}
static struct regulator_ops regulator_ops_fixed = {
.enable = ab3100_enable_regulator,
.disable = ab3100_disable_regulator,
.is_enabled = ab3100_is_enabled_regulator,
.get_voltage = ab3100_get_voltage_regulator,
};
static struct regulator_ops regulator_ops_variable = {
.enable = ab3100_enable_regulator,
.disable = ab3100_disable_regulator,
.is_enabled = ab3100_is_enabled_regulator,
.get_voltage = ab3100_get_voltage_regulator,
.set_voltage = ab3100_set_voltage_regulator,
.list_voltage = ab3100_list_voltage_regulator,
};
static struct regulator_ops regulator_ops_variable_sleepable = {
.enable = ab3100_enable_regulator,
.disable = ab3100_disable_regulator,
.is_enabled = ab3100_is_enabled_regulator,
.get_voltage = ab3100_get_voltage_regulator,
.set_voltage = ab3100_set_voltage_regulator,
.set_suspend_voltage = ab3100_set_suspend_voltage_regulator,
.list_voltage = ab3100_list_voltage_regulator,
};
/*
* LDO EXT is an external regulator so it is really
* not possible to set any voltage locally here, AB3100
* is an on/off switch plain an simple. The external
* voltage is defined in the board set-up if any.
*/
static struct regulator_ops regulator_ops_external = {
.enable = ab3100_enable_regulator,
.disable = ab3100_disable_regulator,
.is_enabled = ab3100_is_enabled_regulator,
.get_voltage = ab3100_get_voltage_regulator_external,
};
static struct regulator_desc
ab3100_regulator_desc[AB3100_NUM_REGULATORS] = {
{
.name = "LDO_A",
.id = AB3100_LDO_A,
.ops = ®ulator_ops_fixed,
.type = REGULATOR_VOLTAGE,
},
{
.name = "LDO_C",
.id = AB3100_LDO_C,
.ops = ®ulator_ops_fixed,
.type = REGULATOR_VOLTAGE,
},
{
.name = "LDO_D",
.id = AB3100_LDO_D,
.ops = ®ulator_ops_fixed,
.type = REGULATOR_VOLTAGE,
},
{
.name = "LDO_E",
.id = AB3100_LDO_E,
.ops = ®ulator_ops_variable_sleepable,
.n_voltages = ARRAY_SIZE(ldo_e_buck_typ_voltages),
.type = REGULATOR_VOLTAGE,
},
{
.name = "LDO_F",
.id = AB3100_LDO_F,
.ops = ®ulator_ops_variable,
.n_voltages = ARRAY_SIZE(ldo_f_typ_voltages),
.type = REGULATOR_VOLTAGE,
},
{
.name = "LDO_G",
.id = AB3100_LDO_G,
.ops = ®ulator_ops_variable,
.n_voltages = ARRAY_SIZE(ldo_g_typ_voltages),
.type = REGULATOR_VOLTAGE,
},
{
.name = "LDO_H",
.id = AB3100_LDO_H,
.ops = ®ulator_ops_variable,
.n_voltages = ARRAY_SIZE(ldo_h_typ_voltages),
.type = REGULATOR_VOLTAGE,
},
{
.name = "LDO_K",
.id = AB3100_LDO_K,
.ops = ®ulator_ops_variable,
.n_voltages = ARRAY_SIZE(ldo_k_typ_voltages),
.type = REGULATOR_VOLTAGE,
},
{
.name = "LDO_EXT",
.id = AB3100_LDO_EXT,
.ops = ®ulator_ops_external,
.type = REGULATOR_VOLTAGE,
},
{
.name = "BUCK",
.id = AB3100_BUCK,
.ops = ®ulator_ops_variable_sleepable,
.n_voltages = ARRAY_SIZE(ldo_e_buck_typ_voltages),
.type = REGULATOR_VOLTAGE,
},
};
/*
* NOTE: the following functions are regulators pluralis - it is the
* binding to the AB3100 core driver and the parent platform device
* for all the different regulators.
*/
static int __init ab3100_regulators_probe(struct platform_device *pdev)
{
struct ab3100_platform_data *plfdata = pdev->dev.platform_data;
struct ab3100 *ab3100 = platform_get_drvdata(pdev);
int err = 0;
u8 data;
int i;
/* Check chip state */
err = ab3100_get_register_interruptible(ab3100,
AB3100_LDO_D, &data);
if (err) {
dev_err(&pdev->dev, "could not read initial status of LDO_D\n");
return err;
}
if (data & 0x10)
dev_notice(&pdev->dev,
"chip is already in active mode (Warm start)\n");
else
dev_notice(&pdev->dev,
"chip is in inactive mode (Cold start)\n");
/* Set up regulators */
for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) {
err = ab3100_set_register_interruptible(ab3100,
ab3100_reg_init_order[i],
plfdata->reg_initvals[i]);
if (err) {
dev_err(&pdev->dev, "regulator initialization failed with error %d\n",
err);
return err;
}
}
if (err) {
dev_err(&pdev->dev,
"LDO D regulator initialization failed with error %d\n",
err);
return err;
}
/* Register the regulators */
for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
struct ab3100_regulator *reg = &ab3100_regulators[i];
struct regulator_dev *rdev;
/*
* Initialize per-regulator struct.
* Inherit platform data, this comes down from the
* i2c boarddata, from the machine. So if you want to
* see what it looks like for a certain machine, go
* into the machine I2C setup.
*/
reg->ab3100 = ab3100;
reg->plfdata = plfdata;
/*
* Register the regulator, pass around
* the ab3100_regulator struct
*/
rdev = regulator_register(&ab3100_regulator_desc[i],
&pdev->dev,
&plfdata->reg_constraints[i],
reg);
if (IS_ERR(rdev)) {
err = PTR_ERR(rdev);
dev_err(&pdev->dev,
"%s: failed to register regulator %s err %d\n",
__func__, ab3100_regulator_desc[i].name,
err);
i--;
/* remove the already registered regulators */
while (i > 0) {
regulator_unregister(ab3100_regulators[i].rdev);
i--;
}
return err;
}
/* Then set a pointer back to the registered regulator */
reg->rdev = rdev;
}
return 0;
}
static int __exit ab3100_regulators_remove(struct platform_device *pdev)
{
int i;
for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
struct ab3100_regulator *reg = &ab3100_regulators[i];
regulator_unregister(reg->rdev);
}
return 0;
}
static struct platform_driver ab3100_regulators_driver = {
.driver = {
.name = "ab3100-regulators",
.owner = THIS_MODULE,
},
.probe = ab3100_regulators_probe,
.remove = __exit_p(ab3100_regulators_remove),
};
static __init int ab3100_regulators_init(void)
{
return platform_driver_register(&ab3100_regulators_driver);
}
static __exit void ab3100_regulators_exit(void)
{
platform_driver_register(&ab3100_regulators_driver);
}
subsys_initcall(ab3100_regulators_init);
module_exit(ab3100_regulators_exit);
MODULE_AUTHOR("Mattias Wallin <mattias.wallin@stericsson.com>");
MODULE_DESCRIPTION("AB3100 Regulator driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:ab3100-regulators");
