diff options
Diffstat (limited to 'drivers/iio/adc/men_z188_adc.c')
| -rw-r--r-- | drivers/iio/adc/men_z188_adc.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/drivers/iio/adc/men_z188_adc.c b/drivers/iio/adc/men_z188_adc.c new file mode 100644 index 000000000..49827bb64 --- /dev/null +++ b/drivers/iio/adc/men_z188_adc.c @@ -0,0 +1,179 @@ +/* + * MEN 16z188 Analog to Digial Converter + * + * Copyright (C) 2014 MEN Mikroelektronik GmbH (www.men.de) + * Author: Johannes Thumshirn <johannes.thumshirn@men.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; version 2 of the License. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mcb.h> +#include <linux/io.h> +#include <linux/iio/iio.h> + +#define Z188_ADC_MAX_CHAN 8 +#define Z188_ADC_GAIN 0x0700000 +#define Z188_MODE_VOLTAGE BIT(27) +#define Z188_CFG_AUTO 0x1 +#define Z188_CTRL_REG 0x40 + +#define ADC_DATA(x) (((x) >> 2) & 0x7ffffc) +#define ADC_OVR(x) ((x) & 0x1) + +struct z188_adc { + struct resource *mem; + void __iomem *base; +}; + +#define Z188_ADC_CHANNEL(idx) { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = (idx), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ +} + +static const struct iio_chan_spec z188_adc_iio_channels[] = { + Z188_ADC_CHANNEL(0), + Z188_ADC_CHANNEL(1), + Z188_ADC_CHANNEL(2), + Z188_ADC_CHANNEL(3), + Z188_ADC_CHANNEL(4), + Z188_ADC_CHANNEL(5), + Z188_ADC_CHANNEL(6), + Z188_ADC_CHANNEL(7), +}; + +static int z188_iio_read_raw(struct iio_dev *iio_dev, + struct iio_chan_spec const *chan, + int *val, + int *val2, + long info) +{ + struct z188_adc *adc = iio_priv(iio_dev); + int ret; + u16 tmp; + + switch (info) { + case IIO_CHAN_INFO_RAW: + tmp = readw(adc->base + chan->channel * 4); + + if (ADC_OVR(tmp)) { + dev_info(&iio_dev->dev, + "Oversampling error on ADC channel %d\n", + chan->channel); + return -EIO; + } + *val = ADC_DATA(tmp); + ret = IIO_VAL_INT; + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + +static const struct iio_info z188_adc_info = { + .read_raw = &z188_iio_read_raw, +}; + +static void men_z188_config_channels(void __iomem *addr) +{ + int i; + u32 cfg; + u32 ctl; + + ctl = readl(addr + Z188_CTRL_REG); + ctl |= Z188_CFG_AUTO; + writel(ctl, addr + Z188_CTRL_REG); + + for (i = 0; i < Z188_ADC_MAX_CHAN; i++) { + cfg = readl(addr + i); + cfg &= ~Z188_ADC_GAIN; + cfg |= Z188_MODE_VOLTAGE; + writel(cfg, addr + i); + } +} + +static int men_z188_probe(struct mcb_device *dev, + const struct mcb_device_id *id) +{ + struct z188_adc *adc; + struct iio_dev *indio_dev; + struct resource *mem; + int ret; + + indio_dev = devm_iio_device_alloc(&dev->dev, sizeof(struct z188_adc)); + if (!indio_dev) + return -ENOMEM; + + adc = iio_priv(indio_dev); + indio_dev->name = "z188-adc"; + indio_dev->dev.parent = &dev->dev; + indio_dev->info = &z188_adc_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = z188_adc_iio_channels; + indio_dev->num_channels = ARRAY_SIZE(z188_adc_iio_channels); + + mem = mcb_request_mem(dev, "z188-adc"); + if (IS_ERR(mem)) + return PTR_ERR(mem); + + adc->base = ioremap(mem->start, resource_size(mem)); + if (adc->base == NULL) + goto err; + + men_z188_config_channels(adc->base); + + adc->mem = mem; + mcb_set_drvdata(dev, indio_dev); + + ret = iio_device_register(indio_dev); + if (ret) + goto err_unmap; + + return 0; + +err_unmap: + iounmap(adc->base); +err: + mcb_release_mem(mem); + return -ENXIO; +} + +static void men_z188_remove(struct mcb_device *dev) +{ + struct iio_dev *indio_dev = mcb_get_drvdata(dev); + struct z188_adc *adc = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + iounmap(adc->base); + mcb_release_mem(adc->mem); +} + +static const struct mcb_device_id men_z188_ids[] = { + { .device = 0xbc }, + { } +}; +MODULE_DEVICE_TABLE(mcb, men_z188_ids); + +static struct mcb_driver men_z188_driver = { + .driver = { + .name = "z188-adc", + .owner = THIS_MODULE, + }, + .probe = men_z188_probe, + .remove = men_z188_remove, + .id_table = men_z188_ids, +}; +module_mcb_driver(men_z188_driver); + +MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("IIO ADC driver for MEN 16z188 ADC Core"); +MODULE_ALIAS("mcb:16z188"); |