1 /* 2 * TI LP8788 MFD - ADC driver 3 * 4 * Copyright 2012 Texas Instruments 5 * 6 * Author: Milo(Woogyom) Kim <milo.kim@ti.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12 13 #include <linux/delay.h> 14 #include <linux/iio/iio.h> 15 #include <linux/iio/driver.h> 16 #include <linux/iio/machine.h> 17 #include <linux/mfd/lp8788.h> 18 #include <linux/module.h> 19 #include <linux/mutex.h> 20 #include <linux/platform_device.h> 21 #include <linux/slab.h> 22 23 /* register address */ 24 #define LP8788_ADC_CONF 0x60 25 #define LP8788_ADC_RAW 0x61 26 #define LP8788_ADC_DONE 0x63 27 28 #define ADC_CONV_START 1 29 30 struct lp8788_adc { 31 struct lp8788 *lp; 32 struct iio_map *map; 33 struct mutex lock; 34 }; 35 36 static const int lp8788_scale[LPADC_MAX] = { 37 [LPADC_VBATT_5P5] = 1343101, 38 [LPADC_VIN_CHG] = 3052503, 39 [LPADC_IBATT] = 610500, 40 [LPADC_IC_TEMP] = 61050, 41 [LPADC_VBATT_6P0] = 1465201, 42 [LPADC_VBATT_5P0] = 1221001, 43 [LPADC_ADC1] = 610500, 44 [LPADC_ADC2] = 610500, 45 [LPADC_VDD] = 1025641, 46 [LPADC_VCOIN] = 757020, 47 [LPADC_ADC3] = 610500, 48 [LPADC_ADC4] = 610500, 49 }; 50 51 static int lp8788_get_adc_result(struct lp8788_adc *adc, enum lp8788_adc_id id, 52 int *val) 53 { 54 unsigned int msb; 55 unsigned int lsb; 56 unsigned int result; 57 u8 data; 58 u8 rawdata[2]; 59 int size = ARRAY_SIZE(rawdata); 60 int retry = 5; 61 int ret; 62 63 data = (id << 1) | ADC_CONV_START; 64 ret = lp8788_write_byte(adc->lp, LP8788_ADC_CONF, data); 65 if (ret) 66 goto err_io; 67 68 /* retry until adc conversion is done */ 69 data = 0; 70 while (retry--) { 71 usleep_range(100, 200); 72 73 ret = lp8788_read_byte(adc->lp, LP8788_ADC_DONE, &data); 74 if (ret) 75 goto err_io; 76 77 /* conversion done */ 78 if (data) 79 break; 80 } 81 82 ret = lp8788_read_multi_bytes(adc->lp, LP8788_ADC_RAW, rawdata, size); 83 if (ret) 84 goto err_io; 85 86 msb = (rawdata[0] << 4) & 0x00000ff0; 87 lsb = (rawdata[1] >> 4) & 0x0000000f; 88 result = msb | lsb; 89 *val = result; 90 91 return 0; 92 93 err_io: 94 return ret; 95 } 96 97 static int lp8788_adc_read_raw(struct iio_dev *indio_dev, 98 struct iio_chan_spec const *chan, 99 int *val, int *val2, long mask) 100 { 101 struct lp8788_adc *adc = iio_priv(indio_dev); 102 enum lp8788_adc_id id = chan->channel; 103 int ret; 104 105 mutex_lock(&adc->lock); 106 107 switch (mask) { 108 case IIO_CHAN_INFO_RAW: 109 ret = lp8788_get_adc_result(adc, id, val) ? -EIO : IIO_VAL_INT; 110 break; 111 case IIO_CHAN_INFO_SCALE: 112 *val = lp8788_scale[id] / 1000000; 113 *val2 = lp8788_scale[id] % 1000000; 114 ret = IIO_VAL_INT_PLUS_MICRO; 115 break; 116 default: 117 ret = -EINVAL; 118 break; 119 } 120 121 mutex_unlock(&adc->lock); 122 123 return ret; 124 } 125 126 static const struct iio_info lp8788_adc_info = { 127 .read_raw = &lp8788_adc_read_raw, 128 .driver_module = THIS_MODULE, 129 }; 130 131 #define LP8788_CHAN(_id, _type) { \ 132 .type = _type, \ 133 .indexed = 1, \ 134 .channel = LPADC_##_id, \ 135 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 136 BIT(IIO_CHAN_INFO_SCALE), \ 137 .datasheet_name = #_id, \ 138 } 139 140 static const struct iio_chan_spec lp8788_adc_channels[] = { 141 [LPADC_VBATT_5P5] = LP8788_CHAN(VBATT_5P5, IIO_VOLTAGE), 142 [LPADC_VIN_CHG] = LP8788_CHAN(VIN_CHG, IIO_VOLTAGE), 143 [LPADC_IBATT] = LP8788_CHAN(IBATT, IIO_CURRENT), 144 [LPADC_IC_TEMP] = LP8788_CHAN(IC_TEMP, IIO_TEMP), 145 [LPADC_VBATT_6P0] = LP8788_CHAN(VBATT_6P0, IIO_VOLTAGE), 146 [LPADC_VBATT_5P0] = LP8788_CHAN(VBATT_5P0, IIO_VOLTAGE), 147 [LPADC_ADC1] = LP8788_CHAN(ADC1, IIO_VOLTAGE), 148 [LPADC_ADC2] = LP8788_CHAN(ADC2, IIO_VOLTAGE), 149 [LPADC_VDD] = LP8788_CHAN(VDD, IIO_VOLTAGE), 150 [LPADC_VCOIN] = LP8788_CHAN(VCOIN, IIO_VOLTAGE), 151 [LPADC_ADC3] = LP8788_CHAN(ADC3, IIO_VOLTAGE), 152 [LPADC_ADC4] = LP8788_CHAN(ADC4, IIO_VOLTAGE), 153 }; 154 155 /* default maps used by iio consumer (lp8788-charger driver) */ 156 static struct iio_map lp8788_default_iio_maps[] = { 157 { 158 .consumer_dev_name = "lp8788-charger", 159 .consumer_channel = "lp8788_vbatt_5p0", 160 .adc_channel_label = "VBATT_5P0", 161 }, 162 { 163 .consumer_dev_name = "lp8788-charger", 164 .consumer_channel = "lp8788_adc1", 165 .adc_channel_label = "ADC1", 166 }, 167 { } 168 }; 169 170 static int lp8788_iio_map_register(struct iio_dev *indio_dev, 171 struct lp8788_platform_data *pdata, 172 struct lp8788_adc *adc) 173 { 174 struct iio_map *map; 175 int ret; 176 177 map = (!pdata || !pdata->adc_pdata) ? 178 lp8788_default_iio_maps : pdata->adc_pdata; 179 180 ret = iio_map_array_register(indio_dev, map); 181 if (ret) { 182 dev_err(&indio_dev->dev, "iio map err: %d\n", ret); 183 return ret; 184 } 185 186 adc->map = map; 187 return 0; 188 } 189 190 static int lp8788_adc_probe(struct platform_device *pdev) 191 { 192 struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent); 193 struct iio_dev *indio_dev; 194 struct lp8788_adc *adc; 195 int ret; 196 197 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc)); 198 if (!indio_dev) 199 return -ENOMEM; 200 201 adc = iio_priv(indio_dev); 202 adc->lp = lp; 203 platform_set_drvdata(pdev, indio_dev); 204 205 indio_dev->dev.of_node = pdev->dev.of_node; 206 ret = lp8788_iio_map_register(indio_dev, lp->pdata, adc); 207 if (ret) 208 return ret; 209 210 mutex_init(&adc->lock); 211 212 indio_dev->dev.parent = &pdev->dev; 213 indio_dev->name = pdev->name; 214 indio_dev->modes = INDIO_DIRECT_MODE; 215 indio_dev->info = &lp8788_adc_info; 216 indio_dev->channels = lp8788_adc_channels; 217 indio_dev->num_channels = ARRAY_SIZE(lp8788_adc_channels); 218 219 ret = iio_device_register(indio_dev); 220 if (ret) { 221 dev_err(&pdev->dev, "iio dev register err: %d\n", ret); 222 goto err_iio_device; 223 } 224 225 return 0; 226 227 err_iio_device: 228 iio_map_array_unregister(indio_dev); 229 return ret; 230 } 231 232 static int lp8788_adc_remove(struct platform_device *pdev) 233 { 234 struct iio_dev *indio_dev = platform_get_drvdata(pdev); 235 236 iio_device_unregister(indio_dev); 237 iio_map_array_unregister(indio_dev); 238 239 return 0; 240 } 241 242 static struct platform_driver lp8788_adc_driver = { 243 .probe = lp8788_adc_probe, 244 .remove = lp8788_adc_remove, 245 .driver = { 246 .name = LP8788_DEV_ADC, 247 }, 248 }; 249 module_platform_driver(lp8788_adc_driver); 250 251 MODULE_DESCRIPTION("Texas Instruments LP8788 ADC Driver"); 252 MODULE_AUTHOR("Milo Kim"); 253 MODULE_LICENSE("GPL"); 254 MODULE_ALIAS("platform:lp8788-adc"); 255