/* * 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; 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); return iio_device_register(indio_dev); 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");