diff options
Diffstat (limited to 'drivers/iio/adc/lp8788_adc.c')
| -rw-r--r-- | drivers/iio/adc/lp8788_adc.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/drivers/iio/adc/lp8788_adc.c b/drivers/iio/adc/lp8788_adc.c new file mode 100644 index 00000000000..a93aaf0bb84 --- /dev/null +++ b/drivers/iio/adc/lp8788_adc.c @@ -0,0 +1,264 @@ +/* + * TI LP8788 MFD - ADC driver + * + * Copyright 2012 Texas Instruments + * + * Author: Milo(Woogyom) Kim <milo.kim@ti.com> + * + * 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. + */ + +#include <linux/delay.h> +#include <linux/iio/iio.h> +#include <linux/iio/driver.h> +#include <linux/iio/machine.h> +#include <linux/mfd/lp8788.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +/* register address */ +#define LP8788_ADC_CONF 0x60 +#define LP8788_ADC_RAW 0x61 +#define LP8788_ADC_DONE 0x63 + +#define ADC_CONV_START 1 + +struct lp8788_adc { + struct lp8788 *lp; + struct iio_map *map; + struct mutex lock; +}; + +static const int lp8788_scale[LPADC_MAX] = { + [LPADC_VBATT_5P5] = 1343101, + [LPADC_VIN_CHG] = 3052503, + [LPADC_IBATT] = 610500, + [LPADC_IC_TEMP] = 61050, + [LPADC_VBATT_6P0] = 1465201, + [LPADC_VBATT_5P0] = 1221001, + [LPADC_ADC1] = 610500, + [LPADC_ADC2] = 610500, + [LPADC_VDD] = 1025641, + [LPADC_VCOIN] = 757020, + [LPADC_ADC3] = 610500, + [LPADC_ADC4] = 610500, +}; + +static int lp8788_get_adc_result(struct lp8788_adc *adc, enum lp8788_adc_id id, + int *val) +{ + unsigned int msb; + unsigned int lsb; + unsigned int result; + u8 data; + u8 rawdata[2]; + int size = ARRAY_SIZE(rawdata); + int retry = 5; + int ret; + + data = (id << 1) | ADC_CONV_START; + ret = lp8788_write_byte(adc->lp, LP8788_ADC_CONF, data); + if (ret) + goto err_io; + + /* retry until adc conversion is done */ + data = 0; + while (retry--) { + usleep_range(100, 200); + + ret = lp8788_read_byte(adc->lp, LP8788_ADC_DONE, &data); + if (ret) + goto err_io; + + /* conversion done */ + if (data) + break; + } + + ret = lp8788_read_multi_bytes(adc->lp, LP8788_ADC_RAW, rawdata, size); + if (ret) + goto err_io; + + msb = (rawdata[0] << 4) & 0x00000ff0; + lsb = (rawdata[1] >> 4) & 0x0000000f; + result = msb | lsb; + *val = result; + + return 0; + +err_io: + return ret; +} + +static int lp8788_adc_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct lp8788_adc *adc = iio_priv(indio_dev); + enum lp8788_adc_id id = chan->channel; + int ret; + + mutex_lock(&adc->lock); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = lp8788_get_adc_result(adc, id, val) ? -EIO : IIO_VAL_INT; + break; + case IIO_CHAN_INFO_SCALE: + *val = lp8788_scale[id] / 1000000; + *val2 = lp8788_scale[id] % 1000000; + ret = IIO_VAL_INT_PLUS_MICRO; + break; + default: + ret = -EINVAL; + break; + } + + mutex_unlock(&adc->lock); + + return ret; +} + +static const struct iio_info lp8788_adc_info = { + .read_raw = &lp8788_adc_read_raw, + .driver_module = THIS_MODULE, +}; + +#define LP8788_CHAN(_id, _type) { \ + .type = _type, \ + .indexed = 1, \ + .channel = LPADC_##_id, \ + .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \ + IIO_CHAN_INFO_SCALE_SEPARATE_BIT, \ + .datasheet_name = #_id, \ +} + +static const struct iio_chan_spec lp8788_adc_channels[] = { + [LPADC_VBATT_5P5] = LP8788_CHAN(VBATT_5P5, IIO_VOLTAGE), + [LPADC_VIN_CHG] = LP8788_CHAN(VIN_CHG, IIO_VOLTAGE), + [LPADC_IBATT] = LP8788_CHAN(IBATT, IIO_CURRENT), + [LPADC_IC_TEMP] = LP8788_CHAN(IC_TEMP, IIO_TEMP), + [LPADC_VBATT_6P0] = LP8788_CHAN(VBATT_6P0, IIO_VOLTAGE), + [LPADC_VBATT_5P0] = LP8788_CHAN(VBATT_5P0, IIO_VOLTAGE), + [LPADC_ADC1] = LP8788_CHAN(ADC1, IIO_VOLTAGE), + [LPADC_ADC2] = LP8788_CHAN(ADC2, IIO_VOLTAGE), + [LPADC_VDD] = LP8788_CHAN(VDD, IIO_VOLTAGE), + [LPADC_VCOIN] = LP8788_CHAN(VCOIN, IIO_VOLTAGE), + [LPADC_ADC3] = LP8788_CHAN(ADC3, IIO_VOLTAGE), + [LPADC_ADC4] = LP8788_CHAN(ADC4, IIO_VOLTAGE), +}; + +/* default maps used by iio consumer (lp8788-charger driver) */ +static struct iio_map lp8788_default_iio_maps[] = { + { + .consumer_dev_name = "lp8788-charger", + .consumer_channel = "lp8788_vbatt_5p0", + .adc_channel_label = "VBATT_5P0", + }, + { + .consumer_dev_name = "lp8788-charger", + .consumer_channel = "lp8788_adc1", + .adc_channel_label = "ADC1", + }, + { } +}; + +static int lp8788_iio_map_register(struct iio_dev *indio_dev, + struct lp8788_platform_data *pdata, + struct lp8788_adc *adc) +{ + struct iio_map *map; + int ret; + + map = (!pdata || !pdata->adc_pdata) ? + lp8788_default_iio_maps : pdata->adc_pdata; + + ret = iio_map_array_register(indio_dev, map); + if (ret) { + dev_err(adc->lp->dev, "iio map err: %d\n", ret); + return ret; + } + + adc->map = map; + return 0; +} + +static inline void lp8788_iio_map_unregister(struct iio_dev *indio_dev, + struct lp8788_adc *adc) +{ + iio_map_array_unregister(indio_dev, adc->map); +} + +static int __devinit lp8788_adc_probe(struct platform_device *pdev) +{ + struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent); + struct iio_dev *indio_dev; + struct lp8788_adc *adc; + int ret; + + indio_dev = iio_device_alloc(sizeof(*adc)); + if (!indio_dev) + return -ENOMEM; + + adc = iio_priv(indio_dev); + adc->lp = lp; + platform_set_drvdata(pdev, indio_dev); + + ret = lp8788_iio_map_register(indio_dev, lp->pdata, adc); + if (ret) + goto err_iio_map; + + mutex_init(&adc->lock); + + indio_dev->dev.parent = lp->dev; + indio_dev->name = pdev->name; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = &lp8788_adc_info; + indio_dev->channels = lp8788_adc_channels; + indio_dev->num_channels = ARRAY_SIZE(lp8788_adc_channels); + + ret = iio_device_register(indio_dev); + if (ret) { + dev_err(lp->dev, "iio dev register err: %d\n", ret); + goto err_iio_device; + } + + return 0; + +err_iio_device: + lp8788_iio_map_unregister(indio_dev, adc); +err_iio_map: + iio_device_free(indio_dev); + return ret; +} + +static int __devexit lp8788_adc_remove(struct platform_device *pdev) +{ + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + struct lp8788_adc *adc = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + lp8788_iio_map_unregister(indio_dev, adc); + iio_device_free(indio_dev); + + return 0; +} + +static struct platform_driver lp8788_adc_driver = { + .probe = lp8788_adc_probe, + .remove = __devexit_p(lp8788_adc_remove), + .driver = { + .name = LP8788_DEV_ADC, + .owner = THIS_MODULE, + }, +}; +module_platform_driver(lp8788_adc_driver); + +MODULE_DESCRIPTION("Texas Instruments LP8788 ADC Driver"); +MODULE_AUTHOR("Milo Kim"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:lp8788-adc"); |