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linux/drivers/hwmon/da9052-hwmon.c
Martyn Welch b16918a5fd hwmon: (da9052) Increase sample rate when using TSI 
The TSI channel, which is usually used for touchscreen support, but can
be used as 4 general purpose ADCs. When used as a touchscreen interface
the touchscreen driver switches the device into 1ms sampling mode (rather
than the default 10ms economy mode) as recommended by the manufacturer.
When using the TSI channels as a general purpose ADC we are currently not
doing this and testing suggests that this can result in ADC timeouts:

[ 5827.198289] da9052 spi2.0: timeout waiting for ADC conversion interrupt
[ 5827.728293] da9052 spi2.0: timeout waiting for ADC conversion interrupt
[ 5993.808335] da9052 spi2.0: timeout waiting for ADC conversion interrupt
[ 5994.328441] da9052 spi2.0: timeout waiting for ADC conversion interrupt
[ 5994.848291] da9052 spi2.0: timeout waiting for ADC conversion interrupt

Switching to the 1ms timing resolves this issue.

Fixes: 4f16cab19a ("hwmon: da9052: Add support for TSI channel")
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Acked-by: Steve Twiss <stwiss.opensource@diasemi.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2017-10-21 09:03:29 -07:00

540 lines
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/*
* HWMON Driver for Dialog DA9052
*
* Copyright(c) 2012 Dialog Semiconductor Ltd.
*
* Author: David Dajun Chen <dchen@diasemi.com>
*
* 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/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_read_vddout(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_read_ich(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_read_tbat(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_read_vbat(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_read_misc_channel(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_read_tsi(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->hwmon_lock);
ret = __da9052_read_tsi(dev, channel);
mutex_unlock(&hwmon->hwmon_lock);
if (ret < 0)
return ret;
else
return sprintf(buf, "%d\n", input_tsireg_to_mv(hwmon, ret));
}
static ssize_t da9052_read_tjunc(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_read_vbbat(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 show_label(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(in0_input, 0444, da9052_read_vddout, NULL,
DA9052_ADC_VDDOUT);
static SENSOR_DEVICE_ATTR(in0_label, 0444, show_label, NULL,
DA9052_ADC_VDDOUT);
static SENSOR_DEVICE_ATTR(in3_input, 0444, da9052_read_vbat, NULL,
DA9052_ADC_VBAT);
static SENSOR_DEVICE_ATTR(in3_label, 0444, show_label, NULL,
DA9052_ADC_VBAT);
static SENSOR_DEVICE_ATTR(in4_input, 0444, da9052_read_misc_channel, NULL,
DA9052_ADC_IN4);
static SENSOR_DEVICE_ATTR(in4_label, 0444, show_label, NULL,
DA9052_ADC_IN4);
static SENSOR_DEVICE_ATTR(in5_input, 0444, da9052_read_misc_channel, NULL,
DA9052_ADC_IN5);
static SENSOR_DEVICE_ATTR(in5_label, 0444, show_label, NULL,
DA9052_ADC_IN5);
static SENSOR_DEVICE_ATTR(in6_input, 0444, da9052_read_misc_channel, NULL,
DA9052_ADC_IN6);
static SENSOR_DEVICE_ATTR(in6_label, 0444, show_label, NULL,
DA9052_ADC_IN6);
static SENSOR_DEVICE_ATTR(in9_input, 0444, da9052_read_vbbat, NULL,
DA9052_ADC_VBBAT);
static SENSOR_DEVICE_ATTR(in9_label, 0444, show_label, NULL,
DA9052_ADC_VBBAT);
static SENSOR_DEVICE_ATTR(in70_input, 0444, da9052_read_tsi, NULL,
DA9052_ADC_TSI_XP);
static SENSOR_DEVICE_ATTR(in70_label, 0444, show_label, NULL,
DA9052_ADC_TSI_XP);
static SENSOR_DEVICE_ATTR(in71_input, 0444, da9052_read_tsi, NULL,
DA9052_ADC_TSI_XN);
static SENSOR_DEVICE_ATTR(in71_label, 0444, show_label, NULL,
DA9052_ADC_TSI_XN);
static SENSOR_DEVICE_ATTR(in72_input, 0444, da9052_read_tsi, NULL,
DA9052_ADC_TSI_YP);
static SENSOR_DEVICE_ATTR(in72_label, 0444, show_label, NULL,
DA9052_ADC_TSI_YP);
static SENSOR_DEVICE_ATTR(in73_input, 0444, da9052_read_tsi, NULL,
DA9052_ADC_TSI_YN);
static SENSOR_DEVICE_ATTR(in73_label, 0444, show_label, NULL,
DA9052_ADC_TSI_YN);
static SENSOR_DEVICE_ATTR(curr1_input, 0444, da9052_read_ich, NULL,
DA9052_ADC_ICH);
static SENSOR_DEVICE_ATTR(curr1_label, 0444, show_label, NULL,
DA9052_ADC_ICH);
static SENSOR_DEVICE_ATTR(temp2_input, 0444, da9052_read_tbat, NULL,
DA9052_ADC_TBAT);
static SENSOR_DEVICE_ATTR(temp2_label, 0444, show_label, NULL,
DA9052_ADC_TBAT);
static SENSOR_DEVICE_ATTR(temp8_input, 0444, da9052_read_tjunc, NULL,
DA9052_ADC_TJUNC);
static SENSOR_DEVICE_ATTR(temp8_label, 0444, show_label, NULL,
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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