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linux/drivers/regulator/ltc3589.c
Steve Twiss f132da2534
regulator: ltc3589: Fix notifier mutex lock warning 
The mutex for the regulator_dev must be controlled by the caller of
the regulator_notifier_call_chain(), as described in the comment
for that function.

Failure to mutex lock and unlock surrounding the notifier call results
in a kernel WARN_ON_ONCE() which will dump a backtrace for the
regulator_notifier_call_chain() when that function call is first made.
The mutex can be controlled using the regulator_lock/unlock() API.

Fixes: 3eb2c7ecb7 ("regulator: Add LTC3589 support")
Suggested-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-13 15:11:55 +00:00

587 lines
15 KiB
C
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/*
* Linear Technology LTC3589,LTC3589-1 regulator support
*
* Copyright (c) 2014 Philipp Zabel <p.zabel@pengutronix.de>, Pengutronix
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/regmap.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/of_regulator.h>
#define DRIVER_NAME "ltc3589"
#define LTC3589_IRQSTAT 0x02
#define LTC3589_SCR1 0x07
#define LTC3589_OVEN 0x10
#define LTC3589_SCR2 0x12
#define LTC3589_PGSTAT 0x13
#define LTC3589_VCCR 0x20
#define LTC3589_CLIRQ 0x21
#define LTC3589_B1DTV1 0x23
#define LTC3589_B1DTV2 0x24
#define LTC3589_VRRCR 0x25
#define LTC3589_B2DTV1 0x26
#define LTC3589_B2DTV2 0x27
#define LTC3589_B3DTV1 0x29
#define LTC3589_B3DTV2 0x2a
#define LTC3589_L2DTV1 0x32
#define LTC3589_L2DTV2 0x33
#define LTC3589_IRQSTAT_PGOOD_TIMEOUT BIT(3)
#define LTC3589_IRQSTAT_UNDERVOLT_WARN BIT(4)
#define LTC3589_IRQSTAT_UNDERVOLT_FAULT BIT(5)
#define LTC3589_IRQSTAT_THERMAL_WARN BIT(6)
#define LTC3589_IRQSTAT_THERMAL_FAULT BIT(7)
#define LTC3589_OVEN_SW1 BIT(0)
#define LTC3589_OVEN_SW2 BIT(1)
#define LTC3589_OVEN_SW3 BIT(2)
#define LTC3589_OVEN_BB_OUT BIT(3)
#define LTC3589_OVEN_LDO2 BIT(4)
#define LTC3589_OVEN_LDO3 BIT(5)
#define LTC3589_OVEN_LDO4 BIT(6)
#define LTC3589_OVEN_SW_CTRL BIT(7)
#define LTC3589_VCCR_SW1_GO BIT(0)
#define LTC3589_VCCR_SW2_GO BIT(2)
#define LTC3589_VCCR_SW3_GO BIT(4)
#define LTC3589_VCCR_LDO2_GO BIT(6)
enum ltc3589_variant {
LTC3589,
LTC3589_1,
LTC3589_2,
};
enum ltc3589_reg {
LTC3589_SW1,
LTC3589_SW2,
LTC3589_SW3,
LTC3589_BB_OUT,
LTC3589_LDO1,
LTC3589_LDO2,
LTC3589_LDO3,
LTC3589_LDO4,
LTC3589_NUM_REGULATORS,
};
struct ltc3589_regulator {
struct regulator_desc desc;
/* External feedback voltage divider */
unsigned int r1;
unsigned int r2;
};
struct ltc3589 {
struct regmap *regmap;
struct device *dev;
enum ltc3589_variant variant;
struct ltc3589_regulator regulator_descs[LTC3589_NUM_REGULATORS];
struct regulator_dev *regulators[LTC3589_NUM_REGULATORS];
};
static const int ltc3589_ldo4[] = {
2800000, 2500000, 1800000, 3300000,
};
static const int ltc3589_12_ldo4[] = {
1200000, 1800000, 2500000, 3200000,
};
static int ltc3589_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay)
{
struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
int sel, shift;
if (unlikely(ramp_delay <= 0))
return -EINVAL;
/* VRRCR slew rate offsets are the same as VCCR go bit offsets */
shift = ffs(rdev->desc->apply_bit) - 1;
/* The slew rate can be set to 0.88, 1.75, 3.5, or 7 mV/uS */
for (sel = 0; sel < 4; sel++) {
if ((880 << sel) >= ramp_delay) {
return regmap_update_bits(ltc3589->regmap,
LTC3589_VRRCR,
0x3 << shift, sel << shift);
}
}
return -EINVAL;
}
static int ltc3589_set_suspend_voltage(struct regulator_dev *rdev, int uV)
{
struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
int sel;
sel = regulator_map_voltage_linear(rdev, uV, uV);
if (sel < 0)
return sel;
/* DTV2 register follows right after the corresponding DTV1 register */
return regmap_update_bits(ltc3589->regmap, rdev->desc->vsel_reg + 1,
rdev->desc->vsel_mask, sel);
}
static int ltc3589_set_suspend_mode(struct regulator_dev *rdev,
unsigned int mode)
{
struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
int mask, bit = 0;
/* VCCR reference selects are right next to the VCCR go bits */
mask = rdev->desc->apply_bit << 1;
if (mode == REGULATOR_MODE_STANDBY)
bit = mask; /* Select DTV2 */
mask |= rdev->desc->apply_bit;
bit |= rdev->desc->apply_bit;
return regmap_update_bits(ltc3589->regmap, LTC3589_VCCR, mask, bit);
}
/* SW1, SW2, SW3, LDO2 */
static const struct regulator_ops ltc3589_linear_regulator_ops = {
.enable = regulator_enable_regmap,
.disable = regulator_disable_regmap,
.is_enabled = regulator_is_enabled_regmap,
.list_voltage = regulator_list_voltage_linear,
.set_voltage_sel = regulator_set_voltage_sel_regmap,
.get_voltage_sel = regulator_get_voltage_sel_regmap,
.set_ramp_delay = ltc3589_set_ramp_delay,
.set_voltage_time_sel = regulator_set_voltage_time_sel,
.set_suspend_voltage = ltc3589_set_suspend_voltage,
.set_suspend_mode = ltc3589_set_suspend_mode,
};
/* BB_OUT, LDO3 */
static const struct regulator_ops ltc3589_fixed_regulator_ops = {
.enable = regulator_enable_regmap,
.disable = regulator_disable_regmap,
.is_enabled = regulator_is_enabled_regmap,
};
/* LDO1 */
static const struct regulator_ops ltc3589_fixed_standby_regulator_ops = {
};
/* LDO4 */
static const struct regulator_ops ltc3589_table_regulator_ops = {
.enable = regulator_enable_regmap,
.disable = regulator_disable_regmap,
.is_enabled = regulator_is_enabled_regmap,
.list_voltage = regulator_list_voltage_table,
.set_voltage_sel = regulator_set_voltage_sel_regmap,
.get_voltage_sel = regulator_get_voltage_sel_regmap,
};
#define LTC3589_REG(_name, _ops, en_bit, dtv1_reg, dtv_mask, go_bit) \
[LTC3589_ ## _name] = { \
.desc = { \
.name = #_name, \
.n_voltages = (dtv_mask) + 1, \
.min_uV = (go_bit) ? 362500 : 0, \
.uV_step = (go_bit) ? 12500 : 0, \
.ramp_delay = (go_bit) ? 1750 : 0, \
.fixed_uV = (dtv_mask) ? 0 : 800000, \
.ops = &ltc3589_ ## _ops ## _regulator_ops, \
.type = REGULATOR_VOLTAGE, \
.id = LTC3589_ ## _name, \
.owner = THIS_MODULE, \
.vsel_reg = (dtv1_reg), \
.vsel_mask = (dtv_mask), \
.apply_reg = (go_bit) ? LTC3589_VCCR : 0, \
.apply_bit = (go_bit), \
.enable_reg = (en_bit) ? LTC3589_OVEN : 0, \
.enable_mask = (en_bit), \
}, \
}
#define LTC3589_LINEAR_REG(_name, _dtv1) \
LTC3589_REG(_name, linear, LTC3589_OVEN_ ## _name, \
LTC3589_ ## _dtv1, 0x1f, \
LTC3589_VCCR_ ## _name ## _GO)
#define LTC3589_FIXED_REG(_name) \
LTC3589_REG(_name, fixed, LTC3589_OVEN_ ## _name, 0, 0, 0)
static struct ltc3589_regulator ltc3589_regulators[LTC3589_NUM_REGULATORS] = {
LTC3589_LINEAR_REG(SW1, B1DTV1),
LTC3589_LINEAR_REG(SW2, B2DTV1),
LTC3589_LINEAR_REG(SW3, B3DTV1),
LTC3589_FIXED_REG(BB_OUT),
LTC3589_REG(LDO1, fixed_standby, 0, 0, 0, 0),
LTC3589_LINEAR_REG(LDO2, L2DTV1),
LTC3589_FIXED_REG(LDO3),
LTC3589_REG(LDO4, table, LTC3589_OVEN_LDO4, LTC3589_L2DTV2, 0x60, 0),
};
#ifdef CONFIG_OF
static struct of_regulator_match ltc3589_matches[LTC3589_NUM_REGULATORS] = {
{ .name = "sw1", },
{ .name = "sw2", },
{ .name = "sw3", },
{ .name = "bb-out", },
{ .name = "ldo1", }, /* standby */
{ .name = "ldo2", },
{ .name = "ldo3", },
{ .name = "ldo4", },
};
static int ltc3589_parse_regulators_dt(struct ltc3589 *ltc3589)
{
struct device *dev = ltc3589->dev;
struct device_node *node;
int i, ret;
node = of_get_child_by_name(dev->of_node, "regulators");
if (!node) {
dev_err(dev, "regulators node not found\n");
return -EINVAL;
}
ret = of_regulator_match(dev, node, ltc3589_matches,
ARRAY_SIZE(ltc3589_matches));
of_node_put(node);
if (ret < 0) {
dev_err(dev, "Error parsing regulator init data: %d\n", ret);
return ret;
}
if (ret != LTC3589_NUM_REGULATORS) {
dev_err(dev, "Only %d regulators described in device tree\n",
ret);
return -EINVAL;
}
/* Parse feedback voltage dividers. LDO3 and LDO4 don't have them */
for (i = 0; i < LTC3589_LDO3; i++) {
struct ltc3589_regulator *desc = &ltc3589->regulator_descs[i];
struct device_node *np = ltc3589_matches[i].of_node;
u32 vdiv[2];
ret = of_property_read_u32_array(np, "lltc,fb-voltage-divider",
vdiv, 2);
if (ret) {
dev_err(dev, "Failed to parse voltage divider: %d\n",
ret);
return ret;
}
desc->r1 = vdiv[0];
desc->r2 = vdiv[1];
}
return 0;
}
static inline struct regulator_init_data *match_init_data(int index)
{
return ltc3589_matches[index].init_data;
}
static inline struct device_node *match_of_node(int index)
{
return ltc3589_matches[index].of_node;
}
#else
static inline int ltc3589_parse_regulators_dt(struct ltc3589 *ltc3589)
{
return 0;
}
static inline struct regulator_init_data *match_init_data(int index)
{
return NULL;
}
static inline struct device_node *match_of_node(int index)
{
return NULL;
}
#endif
static bool ltc3589_writeable_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case LTC3589_IRQSTAT:
case LTC3589_SCR1:
case LTC3589_OVEN:
case LTC3589_SCR2:
case LTC3589_VCCR:
case LTC3589_CLIRQ:
case LTC3589_B1DTV1:
case LTC3589_B1DTV2:
case LTC3589_VRRCR:
case LTC3589_B2DTV1:
case LTC3589_B2DTV2:
case LTC3589_B3DTV1:
case LTC3589_B3DTV2:
case LTC3589_L2DTV1:
case LTC3589_L2DTV2:
return true;
}
return false;
}
static bool ltc3589_readable_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case LTC3589_IRQSTAT:
case LTC3589_SCR1:
case LTC3589_OVEN:
case LTC3589_SCR2:
case LTC3589_PGSTAT:
case LTC3589_VCCR:
case LTC3589_B1DTV1:
case LTC3589_B1DTV2:
case LTC3589_VRRCR:
case LTC3589_B2DTV1:
case LTC3589_B2DTV2:
case LTC3589_B3DTV1:
case LTC3589_B3DTV2:
case LTC3589_L2DTV1:
case LTC3589_L2DTV2:
return true;
}
return false;
}
static bool ltc3589_volatile_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case LTC3589_IRQSTAT:
case LTC3589_PGSTAT:
case LTC3589_VCCR:
return true;
}
return false;
}
static const struct reg_default ltc3589_reg_defaults[] = {
{ LTC3589_SCR1, 0x00 },
{ LTC3589_OVEN, 0x00 },
{ LTC3589_SCR2, 0x00 },
{ LTC3589_VCCR, 0x00 },
{ LTC3589_B1DTV1, 0x19 },
{ LTC3589_B1DTV2, 0x19 },
{ LTC3589_VRRCR, 0xff },
{ LTC3589_B2DTV1, 0x19 },
{ LTC3589_B2DTV2, 0x19 },
{ LTC3589_B3DTV1, 0x19 },
{ LTC3589_B3DTV2, 0x19 },
{ LTC3589_L2DTV1, 0x19 },
{ LTC3589_L2DTV2, 0x19 },
};
static const struct regmap_config ltc3589_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.writeable_reg = ltc3589_writeable_reg,
.readable_reg = ltc3589_readable_reg,
.volatile_reg = ltc3589_volatile_reg,
.max_register = LTC3589_L2DTV2,
.reg_defaults = ltc3589_reg_defaults,
.num_reg_defaults = ARRAY_SIZE(ltc3589_reg_defaults),
.use_single_read = true,
.use_single_write = true,
.cache_type = REGCACHE_RBTREE,
};
static irqreturn_t ltc3589_isr(int irq, void *dev_id)
{
struct ltc3589 *ltc3589 = dev_id;
unsigned int i, irqstat, event;
regmap_read(ltc3589->regmap, LTC3589_IRQSTAT, &irqstat);
if (irqstat & LTC3589_IRQSTAT_THERMAL_WARN) {
event = REGULATOR_EVENT_OVER_TEMP;
for (i = 0; i < LTC3589_NUM_REGULATORS; i++) {
regulator_lock(ltc3589->regulators[i]);
regulator_notifier_call_chain(ltc3589->regulators[i],
event, NULL);
regulator_unlock(ltc3589->regulators[i]);
}
}
if (irqstat & LTC3589_IRQSTAT_UNDERVOLT_WARN) {
event = REGULATOR_EVENT_UNDER_VOLTAGE;
for (i = 0; i < LTC3589_NUM_REGULATORS; i++) {
regulator_lock(ltc3589->regulators[i]);
regulator_notifier_call_chain(ltc3589->regulators[i],
event, NULL);
regulator_unlock(ltc3589->regulators[i]);
}
}
/* Clear warning condition */
regmap_write(ltc3589->regmap, LTC3589_CLIRQ, 0);
return IRQ_HANDLED;
}
static inline unsigned int ltc3589_scale(unsigned int uV, u32 r1, u32 r2)
{
uint64_t tmp;
if (uV == 0)
return 0;
tmp = (uint64_t)uV * r1;
do_div(tmp, r2);
return uV + (unsigned int)tmp;
}
static void ltc3589_apply_fb_voltage_divider(struct ltc3589_regulator *rdesc)
{
struct regulator_desc *desc = &rdesc->desc;
if (!rdesc->r1 || !rdesc->r2)
return;
desc->min_uV = ltc3589_scale(desc->min_uV, rdesc->r1, rdesc->r2);
desc->uV_step = ltc3589_scale(desc->uV_step, rdesc->r1, rdesc->r2);
desc->fixed_uV = ltc3589_scale(desc->fixed_uV, rdesc->r1, rdesc->r2);
}
static int ltc3589_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct device *dev = &client->dev;
struct ltc3589_regulator *descs;
struct ltc3589 *ltc3589;
int i, ret;
ltc3589 = devm_kzalloc(dev, sizeof(*ltc3589), GFP_KERNEL);
if (!ltc3589)
return -ENOMEM;
i2c_set_clientdata(client, ltc3589);
if (client->dev.of_node)
ltc3589->variant = (enum ltc3589_variant)
of_device_get_match_data(&client->dev);
else
ltc3589->variant = id->driver_data;
ltc3589->dev = dev;
descs = ltc3589->regulator_descs;
memcpy(descs, ltc3589_regulators, sizeof(ltc3589_regulators));
if (ltc3589->variant == LTC3589) {
descs[LTC3589_LDO3].desc.fixed_uV = 1800000;
descs[LTC3589_LDO4].desc.volt_table = ltc3589_ldo4;
} else {
descs[LTC3589_LDO3].desc.fixed_uV = 2800000;
descs[LTC3589_LDO4].desc.volt_table = ltc3589_12_ldo4;
}
ltc3589->regmap = devm_regmap_init_i2c(client, &ltc3589_regmap_config);
if (IS_ERR(ltc3589->regmap)) {
ret = PTR_ERR(ltc3589->regmap);
dev_err(dev, "failed to initialize regmap: %d\n", ret);
return ret;
}
ret = ltc3589_parse_regulators_dt(ltc3589);
if (ret)
return ret;
for (i = 0; i < LTC3589_NUM_REGULATORS; i++) {
struct ltc3589_regulator *rdesc = &ltc3589->regulator_descs[i];
struct regulator_desc *desc = &rdesc->desc;
struct regulator_init_data *init_data;
struct regulator_config config = { };
init_data = match_init_data(i);
if (i < LTC3589_LDO3)
ltc3589_apply_fb_voltage_divider(rdesc);
config.dev = dev;
config.init_data = init_data;
config.driver_data = ltc3589;
config.of_node = match_of_node(i);
ltc3589->regulators[i] = devm_regulator_register(dev, desc,
&config);
if (IS_ERR(ltc3589->regulators[i])) {
ret = PTR_ERR(ltc3589->regulators[i]);
dev_err(dev, "failed to register regulator %s: %d\n",
desc->name, ret);
return ret;
}
}
if (client->irq) {
ret = devm_request_threaded_irq(dev, client->irq, NULL,
ltc3589_isr,
IRQF_TRIGGER_LOW | IRQF_ONESHOT,
client->name, ltc3589);
if (ret) {
dev_err(dev, "Failed to request IRQ: %d\n", ret);
return ret;
}
}
return 0;
}
static const struct i2c_device_id ltc3589_i2c_id[] = {
{ "ltc3589", LTC3589 },
{ "ltc3589-1", LTC3589_1 },
{ "ltc3589-2", LTC3589_2 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ltc3589_i2c_id);
static const struct of_device_id ltc3589_of_match[] = {
{
.compatible = "lltc,ltc3589",
.data = (void *)LTC3589,
},
{
.compatible = "lltc,ltc3589-1",
.data = (void *)LTC3589_1,
},
{
.compatible = "lltc,ltc3589-2",
.data = (void *)LTC3589_2,
},
{ },
};
MODULE_DEVICE_TABLE(of, ltc3589_of_match);
static struct i2c_driver ltc3589_driver = {
.driver = {
.name = DRIVER_NAME,
.of_match_table = of_match_ptr(ltc3589_of_match),
},
.probe = ltc3589_probe,
.id_table = ltc3589_i2c_id,
};
module_i2c_driver(ltc3589_driver);
MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>");
MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC3589(-1,2)");
MODULE_LICENSE("GPL v2");
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