xref: /linux/drivers/iio/adc/men_z188_adc.c (revision 52ceb7731e7c23101a26e91aad81ae30de87b10d)
174aeac4dSJohannes Thumshirn /*
274aeac4dSJohannes Thumshirn  * MEN 16z188 Analog to Digial Converter
374aeac4dSJohannes Thumshirn  *
474aeac4dSJohannes Thumshirn  * Copyright (C) 2014 MEN Mikroelektronik GmbH (www.men.de)
574aeac4dSJohannes Thumshirn  * Author: Johannes Thumshirn <johannes.thumshirn@men.de>
674aeac4dSJohannes Thumshirn  *
774aeac4dSJohannes Thumshirn  * This program is free software; you can redistribute it and/or modify it
874aeac4dSJohannes Thumshirn  * under the terms of the GNU General Public License as published by the Free
974aeac4dSJohannes Thumshirn  * Software Foundation; version 2 of the License.
1074aeac4dSJohannes Thumshirn  */
1174aeac4dSJohannes Thumshirn 
1274aeac4dSJohannes Thumshirn #include <linux/kernel.h>
1374aeac4dSJohannes Thumshirn #include <linux/module.h>
1474aeac4dSJohannes Thumshirn #include <linux/mcb.h>
1535272754SJohannes Thumshirn #include <linux/io.h>
1674aeac4dSJohannes Thumshirn #include <linux/iio/iio.h>
1774aeac4dSJohannes Thumshirn 
1874aeac4dSJohannes Thumshirn #define Z188_ADC_MAX_CHAN	8
1974aeac4dSJohannes Thumshirn #define Z188_ADC_GAIN		0x0700000
2074aeac4dSJohannes Thumshirn #define Z188_MODE_VOLTAGE	BIT(27)
2174aeac4dSJohannes Thumshirn #define Z188_CFG_AUTO		0x1
2274aeac4dSJohannes Thumshirn #define Z188_CTRL_REG		0x40
2374aeac4dSJohannes Thumshirn 
2474aeac4dSJohannes Thumshirn #define ADC_DATA(x) (((x) >> 2) & 0x7ffffc)
2574aeac4dSJohannes Thumshirn #define ADC_OVR(x) ((x) & 0x1)
2674aeac4dSJohannes Thumshirn 
2774aeac4dSJohannes Thumshirn struct z188_adc {
2874aeac4dSJohannes Thumshirn 	struct resource *mem;
2974aeac4dSJohannes Thumshirn 	void __iomem *base;
3074aeac4dSJohannes Thumshirn };
3174aeac4dSJohannes Thumshirn 
3274aeac4dSJohannes Thumshirn #define Z188_ADC_CHANNEL(idx) {					\
3374aeac4dSJohannes Thumshirn 		.type = IIO_VOLTAGE,				\
3474aeac4dSJohannes Thumshirn 		.indexed = 1,					\
3574aeac4dSJohannes Thumshirn 		.channel = (idx),				\
3674aeac4dSJohannes Thumshirn 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),   \
3774aeac4dSJohannes Thumshirn }
3874aeac4dSJohannes Thumshirn 
3974aeac4dSJohannes Thumshirn static const struct iio_chan_spec z188_adc_iio_channels[] = {
4074aeac4dSJohannes Thumshirn 	Z188_ADC_CHANNEL(0),
4174aeac4dSJohannes Thumshirn 	Z188_ADC_CHANNEL(1),
4274aeac4dSJohannes Thumshirn 	Z188_ADC_CHANNEL(2),
4374aeac4dSJohannes Thumshirn 	Z188_ADC_CHANNEL(3),
4474aeac4dSJohannes Thumshirn 	Z188_ADC_CHANNEL(4),
4574aeac4dSJohannes Thumshirn 	Z188_ADC_CHANNEL(5),
4674aeac4dSJohannes Thumshirn 	Z188_ADC_CHANNEL(6),
4774aeac4dSJohannes Thumshirn 	Z188_ADC_CHANNEL(7),
4874aeac4dSJohannes Thumshirn };
4974aeac4dSJohannes Thumshirn 
5074aeac4dSJohannes Thumshirn static int z188_iio_read_raw(struct iio_dev *iio_dev,
5174aeac4dSJohannes Thumshirn 			struct iio_chan_spec const *chan,
5274aeac4dSJohannes Thumshirn 			int *val,
5374aeac4dSJohannes Thumshirn 			int *val2,
5474aeac4dSJohannes Thumshirn 			long info)
5574aeac4dSJohannes Thumshirn {
5674aeac4dSJohannes Thumshirn 	struct z188_adc *adc = iio_priv(iio_dev);
5774aeac4dSJohannes Thumshirn 	int ret;
5874aeac4dSJohannes Thumshirn 	u16 tmp;
5974aeac4dSJohannes Thumshirn 
6074aeac4dSJohannes Thumshirn 	switch (info) {
6174aeac4dSJohannes Thumshirn 	case IIO_CHAN_INFO_RAW:
6274aeac4dSJohannes Thumshirn 		tmp = readw(adc->base + chan->channel * 4);
6374aeac4dSJohannes Thumshirn 
6474aeac4dSJohannes Thumshirn 		if (ADC_OVR(tmp)) {
6574aeac4dSJohannes Thumshirn 			dev_info(&iio_dev->dev,
6674aeac4dSJohannes Thumshirn 				"Oversampling error on ADC channel %d\n",
6774aeac4dSJohannes Thumshirn 				chan->channel);
6874aeac4dSJohannes Thumshirn 			return -EIO;
6974aeac4dSJohannes Thumshirn 		}
7074aeac4dSJohannes Thumshirn 		*val = ADC_DATA(tmp);
7174aeac4dSJohannes Thumshirn 		ret = IIO_VAL_INT;
7274aeac4dSJohannes Thumshirn 		break;
7374aeac4dSJohannes Thumshirn 	default:
7474aeac4dSJohannes Thumshirn 		ret = -EINVAL;
7574aeac4dSJohannes Thumshirn 		break;
7674aeac4dSJohannes Thumshirn 	}
7774aeac4dSJohannes Thumshirn 
7874aeac4dSJohannes Thumshirn 	return ret;
7974aeac4dSJohannes Thumshirn }
8074aeac4dSJohannes Thumshirn 
81*52ceb773SJulia Lawall static const struct iio_info z188_adc_info = {
8274aeac4dSJohannes Thumshirn 	.read_raw = &z188_iio_read_raw,
8374aeac4dSJohannes Thumshirn 	.driver_module = THIS_MODULE,
8474aeac4dSJohannes Thumshirn };
8574aeac4dSJohannes Thumshirn 
8674aeac4dSJohannes Thumshirn static void men_z188_config_channels(void __iomem *addr)
8774aeac4dSJohannes Thumshirn {
8874aeac4dSJohannes Thumshirn 	int i;
8974aeac4dSJohannes Thumshirn 	u32 cfg;
9074aeac4dSJohannes Thumshirn 	u32 ctl;
9174aeac4dSJohannes Thumshirn 
9274aeac4dSJohannes Thumshirn 	ctl = readl(addr + Z188_CTRL_REG);
9374aeac4dSJohannes Thumshirn 	ctl |= Z188_CFG_AUTO;
9474aeac4dSJohannes Thumshirn 	writel(ctl, addr + Z188_CTRL_REG);
9574aeac4dSJohannes Thumshirn 
9674aeac4dSJohannes Thumshirn 	for (i = 0; i < Z188_ADC_MAX_CHAN; i++) {
9774aeac4dSJohannes Thumshirn 		cfg = readl(addr + i);
9874aeac4dSJohannes Thumshirn 		cfg &= ~Z188_ADC_GAIN;
9974aeac4dSJohannes Thumshirn 		cfg |= Z188_MODE_VOLTAGE;
10074aeac4dSJohannes Thumshirn 		writel(cfg, addr + i);
10174aeac4dSJohannes Thumshirn 	}
10274aeac4dSJohannes Thumshirn }
10374aeac4dSJohannes Thumshirn 
10474aeac4dSJohannes Thumshirn static int men_z188_probe(struct mcb_device *dev,
10574aeac4dSJohannes Thumshirn 			const struct mcb_device_id *id)
10674aeac4dSJohannes Thumshirn {
10774aeac4dSJohannes Thumshirn 	struct z188_adc *adc;
10874aeac4dSJohannes Thumshirn 	struct iio_dev *indio_dev;
10974aeac4dSJohannes Thumshirn 	struct resource *mem;
11074aeac4dSJohannes Thumshirn 
11174aeac4dSJohannes Thumshirn 	indio_dev = devm_iio_device_alloc(&dev->dev, sizeof(struct z188_adc));
11274aeac4dSJohannes Thumshirn 	if (!indio_dev)
11374aeac4dSJohannes Thumshirn 		return -ENOMEM;
11474aeac4dSJohannes Thumshirn 
11574aeac4dSJohannes Thumshirn 	adc = iio_priv(indio_dev);
11674aeac4dSJohannes Thumshirn 	indio_dev->name = "z188-adc";
11774aeac4dSJohannes Thumshirn 	indio_dev->dev.parent = &dev->dev;
11874aeac4dSJohannes Thumshirn 	indio_dev->info = &z188_adc_info;
11974aeac4dSJohannes Thumshirn 	indio_dev->modes = INDIO_DIRECT_MODE;
12074aeac4dSJohannes Thumshirn 	indio_dev->channels = z188_adc_iio_channels;
12174aeac4dSJohannes Thumshirn 	indio_dev->num_channels = ARRAY_SIZE(z188_adc_iio_channels);
12274aeac4dSJohannes Thumshirn 
12374aeac4dSJohannes Thumshirn 	mem = mcb_request_mem(dev, "z188-adc");
124e94f62e7SDan Carpenter 	if (IS_ERR(mem))
125e94f62e7SDan Carpenter 		return PTR_ERR(mem);
12674aeac4dSJohannes Thumshirn 
12774aeac4dSJohannes Thumshirn 	adc->base = ioremap(mem->start, resource_size(mem));
12874aeac4dSJohannes Thumshirn 	if (adc->base == NULL)
12974aeac4dSJohannes Thumshirn 		goto err;
13074aeac4dSJohannes Thumshirn 
13174aeac4dSJohannes Thumshirn 	men_z188_config_channels(adc->base);
13274aeac4dSJohannes Thumshirn 
13374aeac4dSJohannes Thumshirn 	adc->mem = mem;
13474aeac4dSJohannes Thumshirn 	mcb_set_drvdata(dev, indio_dev);
13574aeac4dSJohannes Thumshirn 
13674aeac4dSJohannes Thumshirn 	return iio_device_register(indio_dev);
13774aeac4dSJohannes Thumshirn 
13874aeac4dSJohannes Thumshirn err:
13974aeac4dSJohannes Thumshirn 	mcb_release_mem(mem);
14074aeac4dSJohannes Thumshirn 	return -ENXIO;
14174aeac4dSJohannes Thumshirn }
14274aeac4dSJohannes Thumshirn 
14374aeac4dSJohannes Thumshirn static void men_z188_remove(struct mcb_device *dev)
14474aeac4dSJohannes Thumshirn {
14574aeac4dSJohannes Thumshirn 	struct iio_dev *indio_dev  = mcb_get_drvdata(dev);
14674aeac4dSJohannes Thumshirn 	struct z188_adc *adc = iio_priv(indio_dev);
14774aeac4dSJohannes Thumshirn 
14874aeac4dSJohannes Thumshirn 	iio_device_unregister(indio_dev);
14974aeac4dSJohannes Thumshirn 	iounmap(adc->base);
15074aeac4dSJohannes Thumshirn 	mcb_release_mem(adc->mem);
15174aeac4dSJohannes Thumshirn }
15274aeac4dSJohannes Thumshirn 
15374aeac4dSJohannes Thumshirn static const struct mcb_device_id men_z188_ids[] = {
15474aeac4dSJohannes Thumshirn 	{ .device = 0xbc },
155fbbba1f8SAxel Lin 	{ }
15674aeac4dSJohannes Thumshirn };
15774aeac4dSJohannes Thumshirn MODULE_DEVICE_TABLE(mcb, men_z188_ids);
15874aeac4dSJohannes Thumshirn 
15974aeac4dSJohannes Thumshirn static struct mcb_driver men_z188_driver = {
16074aeac4dSJohannes Thumshirn 	.driver = {
16174aeac4dSJohannes Thumshirn 		.name = "z188-adc",
16274aeac4dSJohannes Thumshirn 		.owner = THIS_MODULE,
16374aeac4dSJohannes Thumshirn 	},
16474aeac4dSJohannes Thumshirn 	.probe = men_z188_probe,
16574aeac4dSJohannes Thumshirn 	.remove = men_z188_remove,
16674aeac4dSJohannes Thumshirn 	.id_table = men_z188_ids,
16774aeac4dSJohannes Thumshirn };
16874aeac4dSJohannes Thumshirn module_mcb_driver(men_z188_driver);
16974aeac4dSJohannes Thumshirn 
17074aeac4dSJohannes Thumshirn MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>");
17174aeac4dSJohannes Thumshirn MODULE_LICENSE("GPL");
17274aeac4dSJohannes Thumshirn MODULE_DESCRIPTION("IIO ADC driver for MEN 16z188 ADC Core");
17374aeac4dSJohannes Thumshirn MODULE_ALIAS("mcb:16z188");
174