diff options
Diffstat (limited to 'drivers/iio/adc/axp288_adc.c')
| -rw-r--r-- | drivers/iio/adc/axp288_adc.c | 338 |
1 files changed, 338 insertions, 0 deletions
diff --git a/drivers/iio/adc/axp288_adc.c b/drivers/iio/adc/axp288_adc.c new file mode 100644 index 000000000..e6ce25bcc --- /dev/null +++ b/drivers/iio/adc/axp288_adc.c @@ -0,0 +1,338 @@ +/* + * axp288_adc.c - X-Powers AXP288 PMIC ADC Driver + * + * Copyright (C) 2014 Intel Corporation + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * 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; version 2 of the License. + * + * 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/dmi.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/device.h> +#include <linux/regmap.h> +#include <linux/mfd/axp20x.h> +#include <linux/platform_device.h> + +#include <linux/iio/iio.h> +#include <linux/iio/machine.h> +#include <linux/iio/driver.h> + +/* + * This mask enables all ADCs except for the battery temp-sensor (TS), that is + * left as-is to avoid breaking charging on devices without a temp-sensor. + */ +#define AXP288_ADC_EN_MASK 0xF0 +#define AXP288_ADC_TS_ENABLE 0x01 + +#define AXP288_ADC_TS_BIAS_MASK GENMASK(5, 4) +#define AXP288_ADC_TS_BIAS_20UA (0 << 4) +#define AXP288_ADC_TS_BIAS_40UA (1 << 4) +#define AXP288_ADC_TS_BIAS_60UA (2 << 4) +#define AXP288_ADC_TS_BIAS_80UA (3 << 4) +#define AXP288_ADC_TS_CURRENT_ON_OFF_MASK GENMASK(1, 0) +#define AXP288_ADC_TS_CURRENT_OFF (0 << 0) +#define AXP288_ADC_TS_CURRENT_ON_WHEN_CHARGING (1 << 0) +#define AXP288_ADC_TS_CURRENT_ON_ONDEMAND (2 << 0) +#define AXP288_ADC_TS_CURRENT_ON (3 << 0) + +enum axp288_adc_id { + AXP288_ADC_TS, + AXP288_ADC_PMIC, + AXP288_ADC_GP, + AXP288_ADC_BATT_CHRG_I, + AXP288_ADC_BATT_DISCHRG_I, + AXP288_ADC_BATT_V, + AXP288_ADC_NR_CHAN, +}; + +struct axp288_adc_info { + int irq; + struct regmap *regmap; + bool ts_enabled; +}; + +static const struct iio_chan_spec axp288_adc_channels[] = { + { + .indexed = 1, + .type = IIO_TEMP, + .channel = 0, + .address = AXP288_TS_ADC_H, + .datasheet_name = "TS_PIN", + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + }, { + .indexed = 1, + .type = IIO_TEMP, + .channel = 1, + .address = AXP288_PMIC_ADC_H, + .datasheet_name = "PMIC_TEMP", + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + }, { + .indexed = 1, + .type = IIO_TEMP, + .channel = 2, + .address = AXP288_GP_ADC_H, + .datasheet_name = "GPADC", + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + }, { + .indexed = 1, + .type = IIO_CURRENT, + .channel = 3, + .address = AXP20X_BATT_CHRG_I_H, + .datasheet_name = "BATT_CHG_I", + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + }, { + .indexed = 1, + .type = IIO_CURRENT, + .channel = 4, + .address = AXP20X_BATT_DISCHRG_I_H, + .datasheet_name = "BATT_DISCHRG_I", + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + }, { + .indexed = 1, + .type = IIO_VOLTAGE, + .channel = 5, + .address = AXP20X_BATT_V_H, + .datasheet_name = "BATT_V", + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + }, +}; + +/* for consumer drivers */ +static struct iio_map axp288_adc_default_maps[] = { + IIO_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"), + IIO_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"), + IIO_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"), + IIO_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"), + IIO_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"), + IIO_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"), + {}, +}; + +static int axp288_adc_read_channel(int *val, unsigned long address, + struct regmap *regmap) +{ + u8 buf[2]; + + if (regmap_bulk_read(regmap, address, buf, 2)) + return -EIO; + *val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F); + + return IIO_VAL_INT; +} + +/* + * The current-source used for the battery temp-sensor (TS) is shared + * with the GPADC. For proper fuel-gauge and charger operation the TS + * current-source needs to be permanently on. But to read the GPADC we + * need to temporary switch the TS current-source to ondemand, so that + * the GPADC can use it, otherwise we will always read an all 0 value. + */ +static int axp288_adc_set_ts(struct axp288_adc_info *info, + unsigned int mode, unsigned long address) +{ + int ret; + + /* No need to switch the current-source if the TS pin is disabled */ + if (!info->ts_enabled) + return 0; + + /* Channels other than GPADC do not need the current source */ + if (address != AXP288_GP_ADC_H) + return 0; + + ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL, + AXP288_ADC_TS_CURRENT_ON_OFF_MASK, mode); + if (ret) + return ret; + + /* When switching to the GPADC pin give things some time to settle */ + if (mode == AXP288_ADC_TS_CURRENT_ON_ONDEMAND) + usleep_range(6000, 10000); + + return 0; +} + +static int axp288_adc_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + int ret; + struct axp288_adc_info *info = iio_priv(indio_dev); + + mutex_lock(&indio_dev->mlock); + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON_ONDEMAND, + chan->address)) { + dev_err(&indio_dev->dev, "GPADC mode\n"); + ret = -EINVAL; + break; + } + ret = axp288_adc_read_channel(val, chan->address, info->regmap); + if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON, + chan->address)) + dev_err(&indio_dev->dev, "TS pin restore\n"); + break; + default: + ret = -EINVAL; + } + mutex_unlock(&indio_dev->mlock); + + return ret; +} + +/* + * We rely on the machine's firmware to correctly setup the TS pin bias current + * at boot. This lists systems with broken fw where we need to set it ourselves. + */ +static const struct dmi_system_id axp288_adc_ts_bias_override[] = { + { + /* Lenovo Ideapad 100S (11 inch) */ + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), + DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo ideapad 100S-11IBY"), + }, + .driver_data = (void *)(uintptr_t)AXP288_ADC_TS_BIAS_80UA, + }, + {} +}; + +static int axp288_adc_initialize(struct axp288_adc_info *info) +{ + const struct dmi_system_id *bias_override; + int ret, adc_enable_val; + + bias_override = dmi_first_match(axp288_adc_ts_bias_override); + if (bias_override) { + ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL, + AXP288_ADC_TS_BIAS_MASK, + (uintptr_t)bias_override->driver_data); + if (ret) + return ret; + } + + /* + * Determine if the TS pin is enabled and set the TS current-source + * accordingly. + */ + ret = regmap_read(info->regmap, AXP20X_ADC_EN1, &adc_enable_val); + if (ret) + return ret; + + if (adc_enable_val & AXP288_ADC_TS_ENABLE) { + info->ts_enabled = true; + ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL, + AXP288_ADC_TS_CURRENT_ON_OFF_MASK, + AXP288_ADC_TS_CURRENT_ON); + } else { + info->ts_enabled = false; + ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL, + AXP288_ADC_TS_CURRENT_ON_OFF_MASK, + AXP288_ADC_TS_CURRENT_OFF); + } + if (ret) + return ret; + + /* Turn on the ADC for all channels except TS, leave TS as is */ + return regmap_update_bits(info->regmap, AXP20X_ADC_EN1, + AXP288_ADC_EN_MASK, AXP288_ADC_EN_MASK); +} + +static const struct iio_info axp288_adc_iio_info = { + .read_raw = &axp288_adc_read_raw, +}; + +static int axp288_adc_probe(struct platform_device *pdev) +{ + int ret; + struct axp288_adc_info *info; + struct iio_dev *indio_dev; + struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent); + + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info)); + if (!indio_dev) + return -ENOMEM; + + info = iio_priv(indio_dev); + info->irq = platform_get_irq(pdev, 0); + if (info->irq < 0) { + dev_err(&pdev->dev, "no irq resource?\n"); + return info->irq; + } + platform_set_drvdata(pdev, indio_dev); + info->regmap = axp20x->regmap; + /* + * Set ADC to enabled state at all time, including system suspend. + * otherwise internal fuel gauge functionality may be affected. + */ + ret = axp288_adc_initialize(info); + if (ret) { + dev_err(&pdev->dev, "unable to enable ADC device\n"); + return ret; + } + + indio_dev->dev.parent = &pdev->dev; + indio_dev->name = pdev->name; + indio_dev->channels = axp288_adc_channels; + indio_dev->num_channels = ARRAY_SIZE(axp288_adc_channels); + indio_dev->info = &axp288_adc_iio_info; + indio_dev->modes = INDIO_DIRECT_MODE; + ret = iio_map_array_register(indio_dev, axp288_adc_default_maps); + if (ret < 0) + return ret; + + ret = iio_device_register(indio_dev); + if (ret < 0) { + dev_err(&pdev->dev, "unable to register iio device\n"); + goto err_array_unregister; + } + return 0; + +err_array_unregister: + iio_map_array_unregister(indio_dev); + + return ret; +} + +static int axp288_adc_remove(struct platform_device *pdev) +{ + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + + iio_device_unregister(indio_dev); + iio_map_array_unregister(indio_dev); + + return 0; +} + +static const struct platform_device_id axp288_adc_id_table[] = { + { .name = "axp288_adc" }, + {}, +}; + +static struct platform_driver axp288_adc_driver = { + .probe = axp288_adc_probe, + .remove = axp288_adc_remove, + .id_table = axp288_adc_id_table, + .driver = { + .name = "axp288_adc", + }, +}; + +MODULE_DEVICE_TABLE(platform, axp288_adc_id_table); + +module_platform_driver(axp288_adc_driver); + +MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>"); +MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver"); +MODULE_LICENSE("GPL"); |