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linux-next/drivers/hwmon/da9052-hwmon.c
Samu Nuutamo 333e22db22 hwmon: (da9052) Synchronize access with mfd 
When tsi-as-adc is configured it is possible for in7[0123]_input read to
return an incorrect value if a concurrent read to in[456]_input is
performed. This is caused by a concurrent manipulation of the mux
channel without proper locking as hwmon and mfd use different locks for
synchronization.

Switch hwmon to use the same lock as mfd when accessing the TSI channel.

Fixes: 4f16cab19a ("hwmon: da9052: Add support for TSI channel")
Signed-off-by: Samu Nuutamo <samu.nuutamo@vincit.fi>
[rebase to current master, reword commit message slightly]
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2020-05-13 10:06:09 -07:00

508 lines
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* HWMON Driver for Dialog DA9052
*
* Copyright(c) 2012 Dialog Semiconductor Ltd.
*
* Author: David Dajun Chen <dchen@diasemi.com>
*/
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/mfd/da9052/da9052.h>
#include <linux/mfd/da9052/reg.h>
#include <linux/regulator/consumer.h>
struct da9052_hwmon {
struct da9052 *da9052;
struct mutex hwmon_lock;
bool tsi_as_adc;
int tsiref_mv;
struct regulator *tsiref;
struct completion tsidone;
};
static const char * const input_names[] = {
[DA9052_ADC_VDDOUT] = "VDDOUT",
[DA9052_ADC_ICH] = "CHARGING CURRENT",
[DA9052_ADC_TBAT] = "BATTERY TEMP",
[DA9052_ADC_VBAT] = "BATTERY VOLTAGE",
[DA9052_ADC_IN4] = "ADC IN4",
[DA9052_ADC_IN5] = "ADC IN5",
[DA9052_ADC_IN6] = "ADC IN6",
[DA9052_ADC_TSI_XP] = "ADC TS X+",
[DA9052_ADC_TSI_YP] = "ADC TS Y+",
[DA9052_ADC_TSI_XN] = "ADC TS X-",
[DA9052_ADC_TSI_YN] = "ADC TS Y-",
[DA9052_ADC_TJUNC] = "BATTERY JUNCTION TEMP",
[DA9052_ADC_VBBAT] = "BACK-UP BATTERY VOLTAGE",
};
/* Conversion function for VDDOUT and VBAT */
static inline int volt_reg_to_mv(int value)
{
return DIV_ROUND_CLOSEST(value * 2000, 1023) + 2500;
}
/* Conversion function for ADC channels 4, 5 and 6 */
static inline int input_reg_to_mv(int value)
{
return DIV_ROUND_CLOSEST(value * 2500, 1023);
}
/* Conversion function for VBBAT */
static inline int vbbat_reg_to_mv(int value)
{
return DIV_ROUND_CLOSEST(value * 5000, 1023);
}
static inline int input_tsireg_to_mv(struct da9052_hwmon *hwmon, int value)
{
return DIV_ROUND_CLOSEST(value * hwmon->tsiref_mv, 1023);
}
static inline int da9052_enable_vddout_channel(struct da9052 *da9052)
{
return da9052_reg_update(da9052, DA9052_ADC_CONT_REG,
DA9052_ADCCONT_AUTOVDDEN,
DA9052_ADCCONT_AUTOVDDEN);
}
static inline int da9052_disable_vddout_channel(struct da9052 *da9052)
{
return da9052_reg_update(da9052, DA9052_ADC_CONT_REG,
DA9052_ADCCONT_AUTOVDDEN, 0);
}
static ssize_t da9052_vddout_show(struct device *dev,
struct device_attribute *devattr, char *buf)
{
struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
int ret, vdd;
mutex_lock(&hwmon->hwmon_lock);
ret = da9052_enable_vddout_channel(hwmon->da9052);
if (ret < 0)
goto hwmon_err;
vdd = da9052_reg_read(hwmon->da9052, DA9052_VDD_RES_REG);
if (vdd < 0) {
ret = vdd;
goto hwmon_err_release;
}
ret = da9052_disable_vddout_channel(hwmon->da9052);
if (ret < 0)
goto hwmon_err;
mutex_unlock(&hwmon->hwmon_lock);
return sprintf(buf, "%d\n", volt_reg_to_mv(vdd));
hwmon_err_release:
da9052_disable_vddout_channel(hwmon->da9052);
hwmon_err:
mutex_unlock(&hwmon->hwmon_lock);
return ret;
}
static ssize_t da9052_ich_show(struct device *dev,
struct device_attribute *devattr, char *buf)
{
struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
int ret;
ret = da9052_reg_read(hwmon->da9052, DA9052_ICHG_AV_REG);
if (ret < 0)
return ret;
/* Equivalent to 3.9mA/bit in register ICHG_AV */
return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(ret * 39, 10));
}
static ssize_t da9052_tbat_show(struct device *dev,
struct device_attribute *devattr, char *buf)
{
struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
return sprintf(buf, "%d\n", da9052_adc_read_temp(hwmon->da9052));
}
static ssize_t da9052_vbat_show(struct device *dev,
struct device_attribute *devattr, char *buf)
{
struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
int ret;
ret = da9052_adc_manual_read(hwmon->da9052, DA9052_ADC_VBAT);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", volt_reg_to_mv(ret));
}
static ssize_t da9052_misc_channel_show(struct device *dev,
struct device_attribute *devattr,
char *buf)
{
struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
int channel = to_sensor_dev_attr(devattr)->index;
int ret;
ret = da9052_adc_manual_read(hwmon->da9052, channel);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", input_reg_to_mv(ret));
}
static int da9052_request_tsi_read(struct da9052_hwmon *hwmon, int channel)
{
u8 val = DA9052_TSICONTB_TSIMAN;
switch (channel) {
case DA9052_ADC_TSI_XP:
val |= DA9052_TSICONTB_TSIMUX_XP;
break;
case DA9052_ADC_TSI_YP:
val |= DA9052_TSICONTB_TSIMUX_YP;
break;
case DA9052_ADC_TSI_XN:
val |= DA9052_TSICONTB_TSIMUX_XN;
break;
case DA9052_ADC_TSI_YN:
val |= DA9052_TSICONTB_TSIMUX_YN;
break;
}
return da9052_reg_write(hwmon->da9052, DA9052_TSI_CONT_B_REG, val);
}
static int da9052_get_tsi_result(struct da9052_hwmon *hwmon, int channel)
{
u8 regs[3];
int msb, lsb, err;
/* block read to avoid separation of MSB and LSB */
err = da9052_group_read(hwmon->da9052, DA9052_TSI_X_MSB_REG,
ARRAY_SIZE(regs), regs);
if (err)
return err;
switch (channel) {
case DA9052_ADC_TSI_XP:
case DA9052_ADC_TSI_XN:
msb = regs[0] << DA9052_TSILSB_TSIXL_BITS;
lsb = regs[2] & DA9052_TSILSB_TSIXL;
lsb >>= DA9052_TSILSB_TSIXL_SHIFT;
break;
case DA9052_ADC_TSI_YP:
case DA9052_ADC_TSI_YN:
msb = regs[1] << DA9052_TSILSB_TSIYL_BITS;
lsb = regs[2] & DA9052_TSILSB_TSIYL;
lsb >>= DA9052_TSILSB_TSIYL_SHIFT;
break;
default:
return -EINVAL;
}
return msb | lsb;
}
static ssize_t __da9052_read_tsi(struct device *dev, int channel)
{
struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
int ret;
reinit_completion(&hwmon->tsidone);
ret = da9052_request_tsi_read(hwmon, channel);
if (ret < 0)
return ret;
/* Wait for an conversion done interrupt */
if (!wait_for_completion_timeout(&hwmon->tsidone,
msecs_to_jiffies(500)))
return -ETIMEDOUT;
return da9052_get_tsi_result(hwmon, channel);
}
static ssize_t da9052_tsi_show(struct device *dev,
struct device_attribute *devattr, char *buf)
{
struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
int channel = to_sensor_dev_attr(devattr)->index;
int ret;
mutex_lock(&hwmon->da9052->auxadc_lock);
ret = __da9052_read_tsi(dev, channel);
mutex_unlock(&hwmon->da9052->auxadc_lock);
if (ret < 0)
return ret;
else
return sprintf(buf, "%d\n", input_tsireg_to_mv(hwmon, ret));
}
static ssize_t da9052_tjunc_show(struct device *dev,
struct device_attribute *devattr, char *buf)
{
struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
int tjunc;
int toffset;
tjunc = da9052_reg_read(hwmon->da9052, DA9052_TJUNC_RES_REG);
if (tjunc < 0)
return tjunc;
toffset = da9052_reg_read(hwmon->da9052, DA9052_T_OFFSET_REG);
if (toffset < 0)
return toffset;
/*
* Degrees celsius = 1.708 * (TJUNC_RES - T_OFFSET) - 108.8
* T_OFFSET is a trim value used to improve accuracy of the result
*/
return sprintf(buf, "%d\n", 1708 * (tjunc - toffset) - 108800);
}
static ssize_t da9052_vbbat_show(struct device *dev,
struct device_attribute *devattr, char *buf)
{
struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
int ret;
ret = da9052_adc_manual_read(hwmon->da9052, DA9052_ADC_VBBAT);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", vbbat_reg_to_mv(ret));
}
static ssize_t label_show(struct device *dev,
struct device_attribute *devattr, char *buf)
{
return sprintf(buf, "%s\n",
input_names[to_sensor_dev_attr(devattr)->index]);
}
static umode_t da9052_channel_is_visible(struct kobject *kobj,
struct attribute *attr, int index)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
struct device_attribute *dattr = container_of(attr,
struct device_attribute, attr);
struct sensor_device_attribute *sattr = to_sensor_dev_attr(dattr);
if (!hwmon->tsi_as_adc) {
switch (sattr->index) {
case DA9052_ADC_TSI_XP:
case DA9052_ADC_TSI_YP:
case DA9052_ADC_TSI_XN:
case DA9052_ADC_TSI_YN:
return 0;
}
}
return attr->mode;
}
static SENSOR_DEVICE_ATTR_RO(in0_input, da9052_vddout, DA9052_ADC_VDDOUT);
static SENSOR_DEVICE_ATTR_RO(in0_label, label, DA9052_ADC_VDDOUT);
static SENSOR_DEVICE_ATTR_RO(in3_input, da9052_vbat, DA9052_ADC_VBAT);
static SENSOR_DEVICE_ATTR_RO(in3_label, label, DA9052_ADC_VBAT);
static SENSOR_DEVICE_ATTR_RO(in4_input, da9052_misc_channel, DA9052_ADC_IN4);
static SENSOR_DEVICE_ATTR_RO(in4_label, label, DA9052_ADC_IN4);
static SENSOR_DEVICE_ATTR_RO(in5_input, da9052_misc_channel, DA9052_ADC_IN5);
static SENSOR_DEVICE_ATTR_RO(in5_label, label, DA9052_ADC_IN5);
static SENSOR_DEVICE_ATTR_RO(in6_input, da9052_misc_channel, DA9052_ADC_IN6);
static SENSOR_DEVICE_ATTR_RO(in6_label, label, DA9052_ADC_IN6);
static SENSOR_DEVICE_ATTR_RO(in9_input, da9052_vbbat, DA9052_ADC_VBBAT);
static SENSOR_DEVICE_ATTR_RO(in9_label, label, DA9052_ADC_VBBAT);
static SENSOR_DEVICE_ATTR_RO(in70_input, da9052_tsi, DA9052_ADC_TSI_XP);
static SENSOR_DEVICE_ATTR_RO(in70_label, label, DA9052_ADC_TSI_XP);
static SENSOR_DEVICE_ATTR_RO(in71_input, da9052_tsi, DA9052_ADC_TSI_XN);
static SENSOR_DEVICE_ATTR_RO(in71_label, label, DA9052_ADC_TSI_XN);
static SENSOR_DEVICE_ATTR_RO(in72_input, da9052_tsi, DA9052_ADC_TSI_YP);
static SENSOR_DEVICE_ATTR_RO(in72_label, label, DA9052_ADC_TSI_YP);
static SENSOR_DEVICE_ATTR_RO(in73_input, da9052_tsi, DA9052_ADC_TSI_YN);
static SENSOR_DEVICE_ATTR_RO(in73_label, label, DA9052_ADC_TSI_YN);
static SENSOR_DEVICE_ATTR_RO(curr1_input, da9052_ich, DA9052_ADC_ICH);
static SENSOR_DEVICE_ATTR_RO(curr1_label, label, DA9052_ADC_ICH);
static SENSOR_DEVICE_ATTR_RO(temp2_input, da9052_tbat, DA9052_ADC_TBAT);
static SENSOR_DEVICE_ATTR_RO(temp2_label, label, DA9052_ADC_TBAT);
static SENSOR_DEVICE_ATTR_RO(temp8_input, da9052_tjunc, DA9052_ADC_TJUNC);
static SENSOR_DEVICE_ATTR_RO(temp8_label, label, DA9052_ADC_TJUNC);
static struct attribute *da9052_attrs[] = {
&sensor_dev_attr_in0_input.dev_attr.attr,
&sensor_dev_attr_in0_label.dev_attr.attr,
&sensor_dev_attr_in3_input.dev_attr.attr,
&sensor_dev_attr_in3_label.dev_attr.attr,
&sensor_dev_attr_in4_input.dev_attr.attr,
&sensor_dev_attr_in4_label.dev_attr.attr,
&sensor_dev_attr_in5_input.dev_attr.attr,
&sensor_dev_attr_in5_label.dev_attr.attr,
&sensor_dev_attr_in6_input.dev_attr.attr,
&sensor_dev_attr_in6_label.dev_attr.attr,
&sensor_dev_attr_in70_input.dev_attr.attr,
&sensor_dev_attr_in70_label.dev_attr.attr,
&sensor_dev_attr_in71_input.dev_attr.attr,
&sensor_dev_attr_in71_label.dev_attr.attr,
&sensor_dev_attr_in72_input.dev_attr.attr,
&sensor_dev_attr_in72_label.dev_attr.attr,
&sensor_dev_attr_in73_input.dev_attr.attr,
&sensor_dev_attr_in73_label.dev_attr.attr,
&sensor_dev_attr_in9_input.dev_attr.attr,
&sensor_dev_attr_in9_label.dev_attr.attr,
&sensor_dev_attr_curr1_input.dev_attr.attr,
&sensor_dev_attr_curr1_label.dev_attr.attr,
&sensor_dev_attr_temp2_input.dev_attr.attr,
&sensor_dev_attr_temp2_label.dev_attr.attr,
&sensor_dev_attr_temp8_input.dev_attr.attr,
&sensor_dev_attr_temp8_label.dev_attr.attr,
NULL
};
static const struct attribute_group da9052_group = {
.attrs = da9052_attrs,
.is_visible = da9052_channel_is_visible,
};
__ATTRIBUTE_GROUPS(da9052);
static irqreturn_t da9052_tsi_datardy_irq(int irq, void *data)
{
struct da9052_hwmon *hwmon = data;
complete(&hwmon->tsidone);
return IRQ_HANDLED;
}
static int da9052_hwmon_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct da9052_hwmon *hwmon;
struct device *hwmon_dev;
int err;
hwmon = devm_kzalloc(dev, sizeof(struct da9052_hwmon), GFP_KERNEL);
if (!hwmon)
return -ENOMEM;
platform_set_drvdata(pdev, hwmon);
mutex_init(&hwmon->hwmon_lock);
hwmon->da9052 = dev_get_drvdata(pdev->dev.parent);
init_completion(&hwmon->tsidone);
hwmon->tsi_as_adc =
device_property_read_bool(pdev->dev.parent, "dlg,tsi-as-adc");
if (hwmon->tsi_as_adc) {
hwmon->tsiref = devm_regulator_get(pdev->dev.parent, "tsiref");
if (IS_ERR(hwmon->tsiref)) {
err = PTR_ERR(hwmon->tsiref);
dev_err(&pdev->dev, "failed to get tsiref: %d", err);
return err;
}
err = regulator_enable(hwmon->tsiref);
if (err)
return err;
hwmon->tsiref_mv = regulator_get_voltage(hwmon->tsiref);
if (hwmon->tsiref_mv < 0) {
err = hwmon->tsiref_mv;
goto exit_regulator;
}
/* convert from microvolt (DT) to millivolt (hwmon) */
hwmon->tsiref_mv /= 1000;
/* TSIREF limits from datasheet */
if (hwmon->tsiref_mv < 1800 || hwmon->tsiref_mv > 2600) {
dev_err(hwmon->da9052->dev, "invalid TSIREF voltage: %d",
hwmon->tsiref_mv);
err = -ENXIO;
goto exit_regulator;
}
/* disable touchscreen features */
da9052_reg_write(hwmon->da9052, DA9052_TSI_CONT_A_REG, 0x00);
/* Sample every 1ms */
da9052_reg_update(hwmon->da9052, DA9052_ADC_CONT_REG,
DA9052_ADCCONT_ADCMODE,
DA9052_ADCCONT_ADCMODE);
err = da9052_request_irq(hwmon->da9052, DA9052_IRQ_TSIREADY,
"tsiready-irq", da9052_tsi_datardy_irq,
hwmon);
if (err) {
dev_err(&pdev->dev, "Failed to register TSIRDY IRQ: %d",
err);
goto exit_regulator;
}
}
hwmon_dev = devm_hwmon_device_register_with_groups(dev, "da9052",
hwmon,
da9052_groups);
err = PTR_ERR_OR_ZERO(hwmon_dev);
if (err)
goto exit_irq;
return 0;
exit_irq:
if (hwmon->tsi_as_adc)
da9052_free_irq(hwmon->da9052, DA9052_IRQ_TSIREADY, hwmon);
exit_regulator:
if (hwmon->tsiref)
regulator_disable(hwmon->tsiref);
return err;
}
static int da9052_hwmon_remove(struct platform_device *pdev)
{
struct da9052_hwmon *hwmon = platform_get_drvdata(pdev);
if (hwmon->tsi_as_adc) {
da9052_free_irq(hwmon->da9052, DA9052_IRQ_TSIREADY, hwmon);
regulator_disable(hwmon->tsiref);
}
return 0;
}
static struct platform_driver da9052_hwmon_driver = {
.probe = da9052_hwmon_probe,
.remove = da9052_hwmon_remove,
.driver = {
.name = "da9052-hwmon",
},
};
module_platform_driver(da9052_hwmon_driver);
MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
MODULE_DESCRIPTION("DA9052 HWMON driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da9052-hwmon");
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