1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * MEN 16z188 Analog to Digial Converter 4 * 5 * Copyright (C) 2014 MEN Mikroelektronik GmbH (www.men.de) 6 * Author: Johannes Thumshirn <johannes.thumshirn@men.de> 7 */ 8 9 #include <linux/kernel.h> 10 #include <linux/module.h> 11 #include <linux/mcb.h> 12 #include <linux/io.h> 13 #include <linux/iio/iio.h> 14 15 #define Z188_ADC_MAX_CHAN 8 16 #define Z188_ADC_GAIN 0x0700000 17 #define Z188_MODE_VOLTAGE BIT(27) 18 #define Z188_CFG_AUTO 0x1 19 #define Z188_CTRL_REG 0x40 20 21 #define ADC_DATA(x) (((x) >> 2) & 0x7ffffc) 22 #define ADC_OVR(x) ((x) & 0x1) 23 24 struct z188_adc { 25 struct resource *mem; 26 void __iomem *base; 27 }; 28 29 #define Z188_ADC_CHANNEL(idx) { \ 30 .type = IIO_VOLTAGE, \ 31 .indexed = 1, \ 32 .channel = (idx), \ 33 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 34 } 35 36 static const struct iio_chan_spec z188_adc_iio_channels[] = { 37 Z188_ADC_CHANNEL(0), 38 Z188_ADC_CHANNEL(1), 39 Z188_ADC_CHANNEL(2), 40 Z188_ADC_CHANNEL(3), 41 Z188_ADC_CHANNEL(4), 42 Z188_ADC_CHANNEL(5), 43 Z188_ADC_CHANNEL(6), 44 Z188_ADC_CHANNEL(7), 45 }; 46 47 static int z188_iio_read_raw(struct iio_dev *iio_dev, 48 struct iio_chan_spec const *chan, 49 int *val, 50 int *val2, 51 long info) 52 { 53 struct z188_adc *adc = iio_priv(iio_dev); 54 int ret; 55 u16 tmp; 56 57 switch (info) { 58 case IIO_CHAN_INFO_RAW: 59 tmp = readw(adc->base + chan->channel * 4); 60 61 if (ADC_OVR(tmp)) { 62 dev_info(&iio_dev->dev, 63 "Oversampling error on ADC channel %d\n", 64 chan->channel); 65 return -EIO; 66 } 67 *val = ADC_DATA(tmp); 68 ret = IIO_VAL_INT; 69 break; 70 default: 71 ret = -EINVAL; 72 break; 73 } 74 75 return ret; 76 } 77 78 static const struct iio_info z188_adc_info = { 79 .read_raw = &z188_iio_read_raw, 80 }; 81 82 static void men_z188_config_channels(void __iomem *addr) 83 { 84 int i; 85 u32 cfg; 86 u32 ctl; 87 88 ctl = readl(addr + Z188_CTRL_REG); 89 ctl |= Z188_CFG_AUTO; 90 writel(ctl, addr + Z188_CTRL_REG); 91 92 for (i = 0; i < Z188_ADC_MAX_CHAN; i++) { 93 cfg = readl(addr + i); 94 cfg &= ~Z188_ADC_GAIN; 95 cfg |= Z188_MODE_VOLTAGE; 96 writel(cfg, addr + i); 97 } 98 } 99 100 static int men_z188_probe(struct mcb_device *dev, 101 const struct mcb_device_id *id) 102 { 103 struct z188_adc *adc; 104 struct iio_dev *indio_dev; 105 struct resource *mem; 106 int ret; 107 108 indio_dev = devm_iio_device_alloc(&dev->dev, sizeof(struct z188_adc)); 109 if (!indio_dev) 110 return -ENOMEM; 111 112 adc = iio_priv(indio_dev); 113 indio_dev->name = "z188-adc"; 114 indio_dev->info = &z188_adc_info; 115 indio_dev->modes = INDIO_DIRECT_MODE; 116 indio_dev->channels = z188_adc_iio_channels; 117 indio_dev->num_channels = ARRAY_SIZE(z188_adc_iio_channels); 118 119 mem = mcb_request_mem(dev, "z188-adc"); 120 if (IS_ERR(mem)) 121 return PTR_ERR(mem); 122 123 adc->base = ioremap(mem->start, resource_size(mem)); 124 if (adc->base == NULL) 125 goto err; 126 127 men_z188_config_channels(adc->base); 128 129 adc->mem = mem; 130 mcb_set_drvdata(dev, indio_dev); 131 132 ret = iio_device_register(indio_dev); 133 if (ret) 134 goto err_unmap; 135 136 return 0; 137 138 err_unmap: 139 iounmap(adc->base); 140 err: 141 mcb_release_mem(mem); 142 return -ENXIO; 143 } 144 145 static void men_z188_remove(struct mcb_device *dev) 146 { 147 struct iio_dev *indio_dev = mcb_get_drvdata(dev); 148 struct z188_adc *adc = iio_priv(indio_dev); 149 150 iio_device_unregister(indio_dev); 151 iounmap(adc->base); 152 mcb_release_mem(adc->mem); 153 } 154 155 static const struct mcb_device_id men_z188_ids[] = { 156 { .device = 0xbc }, 157 { } 158 }; 159 MODULE_DEVICE_TABLE(mcb, men_z188_ids); 160 161 static struct mcb_driver men_z188_driver = { 162 .driver = { 163 .name = "z188-adc", 164 }, 165 .probe = men_z188_probe, 166 .remove = men_z188_remove, 167 .id_table = men_z188_ids, 168 }; 169 module_mcb_driver(men_z188_driver); 170 171 MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>"); 172 MODULE_LICENSE("GPL"); 173 MODULE_DESCRIPTION("IIO ADC driver for MEN 16z188 ADC Core"); 174 MODULE_ALIAS("mcb:16z188"); 175 MODULE_IMPORT_NS(MCB); 176