diff options
Diffstat (limited to 'drivers/iio/adc/lpc32xx_adc.c')
| -rw-r--r-- | drivers/iio/adc/lpc32xx_adc.c | 100 |
1 files changed, 57 insertions, 43 deletions
diff --git a/drivers/iio/adc/lpc32xx_adc.c b/drivers/iio/adc/lpc32xx_adc.c index 20b36690fa4f..43a7bc8158b5 100644 --- a/drivers/iio/adc/lpc32xx_adc.c +++ b/drivers/iio/adc/lpc32xx_adc.c @@ -1,39 +1,23 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * lpc32xx_adc.c - Support for ADC in LPC32XX * * 3-channel, 10-bit ADC * * Copyright (C) 2011, 2012 Roland Stigge <stigge@antcom.de> - * - * 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. - * - * 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. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ -#include <linux/module.h> -#include <linux/platform_device.h> -#include <linux/interrupt.h> -#include <linux/device.h> -#include <linux/kernel.h> -#include <linux/slab.h> -#include <linux/io.h> #include <linux/clk.h> -#include <linux/err.h> #include <linux/completion.h> -#include <linux/of.h> - +#include <linux/err.h> #include <linux/iio/iio.h> -#include <linux/iio/sysfs.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/mutex.h> +#include <linux/platform_device.h> +#include <linux/regulator/consumer.h> /* * LPC32XX registers definitions @@ -65,6 +49,9 @@ struct lpc32xx_adc_state { void __iomem *adc_base; struct clk *clk; struct completion completion; + struct regulator *vref; + /* lock to protect against multiple access to the device */ + struct mutex lock; u32 value; }; @@ -77,11 +64,13 @@ static int lpc32xx_read_raw(struct iio_dev *indio_dev, { struct lpc32xx_adc_state *st = iio_priv(indio_dev); int ret; - if (mask == IIO_CHAN_INFO_RAW) { - mutex_lock(&indio_dev->mlock); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + mutex_lock(&st->lock); ret = clk_prepare_enable(st->clk); if (ret) { - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&st->lock); return ret; } /* Measurement setup */ @@ -94,25 +83,39 @@ static int lpc32xx_read_raw(struct iio_dev *indio_dev, wait_for_completion(&st->completion); /* set by ISR */ clk_disable_unprepare(st->clk); *val = st->value; - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&st->lock); return IIO_VAL_INT; - } - return -EINVAL; + case IIO_CHAN_INFO_SCALE: + *val = regulator_get_voltage(st->vref) / 1000; + *val2 = 10; + + return IIO_VAL_FRACTIONAL_LOG2; + default: + return -EINVAL; + } } static const struct iio_info lpc32xx_adc_iio_info = { .read_raw = &lpc32xx_read_raw, }; -#define LPC32XX_ADC_CHANNEL(_index) { \ +#define LPC32XX_ADC_CHANNEL_BASE(_index) \ .type = IIO_VOLTAGE, \ .indexed = 1, \ .channel = _index, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .address = LPC32XXAD_IN * _index, \ - .scan_index = _index, \ + .scan_index = _index, + +#define LPC32XX_ADC_CHANNEL(_index) { \ + LPC32XX_ADC_CHANNEL_BASE(_index) \ +} + +#define LPC32XX_ADC_SCALE_CHANNEL(_index) { \ + LPC32XX_ADC_CHANNEL_BASE(_index) \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ } static const struct iio_chan_spec lpc32xx_adc_iio_channels[] = { @@ -121,6 +124,12 @@ static const struct iio_chan_spec lpc32xx_adc_iio_channels[] = { LPC32XX_ADC_CHANNEL(2), }; +static const struct iio_chan_spec lpc32xx_adc_iio_scale_channels[] = { + LPC32XX_ADC_SCALE_CHANNEL(0), + LPC32XX_ADC_SCALE_CHANNEL(1), + LPC32XX_ADC_SCALE_CHANNEL(2), +}; + static irqreturn_t lpc32xx_adc_isr(int irq, void *dev_id) { struct lpc32xx_adc_state *st = dev_id; @@ -167,10 +176,8 @@ static int lpc32xx_adc_probe(struct platform_device *pdev) } irq = platform_get_irq(pdev, 0); - if (irq <= 0) { - dev_err(&pdev->dev, "failed getting interrupt resource\n"); - return -ENXIO; - } + if (irq < 0) + return irq; retval = devm_request_irq(&pdev->dev, irq, lpc32xx_adc_isr, 0, LPC32XXAD_NAME, st); @@ -179,17 +186,26 @@ static int lpc32xx_adc_probe(struct platform_device *pdev) return retval; } + st->vref = devm_regulator_get(&pdev->dev, "vref"); + if (IS_ERR(st->vref)) { + iodev->channels = lpc32xx_adc_iio_channels; + dev_info(&pdev->dev, + "Missing vref regulator: No scaling available\n"); + } else { + iodev->channels = lpc32xx_adc_iio_scale_channels; + } + platform_set_drvdata(pdev, iodev); init_completion(&st->completion); iodev->name = LPC32XXAD_NAME; - iodev->dev.parent = &pdev->dev; iodev->info = &lpc32xx_adc_iio_info; iodev->modes = INDIO_DIRECT_MODE; - iodev->channels = lpc32xx_adc_iio_channels; iodev->num_channels = ARRAY_SIZE(lpc32xx_adc_iio_channels); + mutex_init(&st->lock); + retval = devm_iio_device_register(&pdev->dev, iodev); if (retval) return retval; @@ -199,19 +215,17 @@ static int lpc32xx_adc_probe(struct platform_device *pdev) return 0; } -#ifdef CONFIG_OF static const struct of_device_id lpc32xx_adc_match[] = { { .compatible = "nxp,lpc3220-adc" }, - {}, + { } }; MODULE_DEVICE_TABLE(of, lpc32xx_adc_match); -#endif static struct platform_driver lpc32xx_adc_driver = { .probe = lpc32xx_adc_probe, .driver = { .name = LPC32XXAD_NAME, - .of_match_table = of_match_ptr(lpc32xx_adc_match), + .of_match_table = lpc32xx_adc_match, }, }; |