Kim, Milo | f0347c3 | 2012-09-17 10:35:00 +0100 | [diff] [blame] | 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 = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \ |
| 136 | IIO_CHAN_INFO_SCALE_SEPARATE_BIT, \ |
| 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) { |
Kim, Milo | 5306f41 | 2013-01-03 06:28:00 +0000 | [diff] [blame] | 182 | dev_err(&indio_dev->dev, "iio map err: %d\n", ret); |
Kim, Milo | f0347c3 | 2012-09-17 10:35:00 +0100 | [diff] [blame] | 183 | return ret; |
| 184 | } |
| 185 | |
| 186 | adc->map = map; |
| 187 | return 0; |
| 188 | } |
| 189 | |
Greg Kroah-Hartman | fc52692 | 2012-12-21 13:21:43 -0800 | [diff] [blame] | 190 | static int lp8788_adc_probe(struct platform_device *pdev) |
Kim, Milo | f0347c3 | 2012-09-17 10:35:00 +0100 | [diff] [blame] | 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 = iio_device_alloc(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 | |
Guenter Roeck | c3a69e6 | 2013-01-31 21:43:00 +0000 | [diff] [blame] | 205 | indio_dev->dev.of_node = pdev->dev.of_node; |
Kim, Milo | f0347c3 | 2012-09-17 10:35:00 +0100 | [diff] [blame] | 206 | ret = lp8788_iio_map_register(indio_dev, lp->pdata, adc); |
| 207 | if (ret) |
| 208 | goto err_iio_map; |
| 209 | |
| 210 | mutex_init(&adc->lock); |
| 211 | |
Kim, Milo | dc11699 | 2013-01-03 06:28:00 +0000 | [diff] [blame] | 212 | indio_dev->dev.parent = &pdev->dev; |
Kim, Milo | f0347c3 | 2012-09-17 10:35:00 +0100 | [diff] [blame] | 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) { |
Kim, Milo | dc11699 | 2013-01-03 06:28:00 +0000 | [diff] [blame] | 221 | dev_err(&pdev->dev, "iio dev register err: %d\n", ret); |
Kim, Milo | f0347c3 | 2012-09-17 10:35:00 +0100 | [diff] [blame] | 222 | goto err_iio_device; |
| 223 | } |
| 224 | |
| 225 | return 0; |
| 226 | |
| 227 | err_iio_device: |
Guenter Roeck | 6cb2afd | 2013-01-31 21:43:00 +0000 | [diff] [blame^] | 228 | iio_map_array_unregister(indio_dev); |
Kim, Milo | f0347c3 | 2012-09-17 10:35:00 +0100 | [diff] [blame] | 229 | err_iio_map: |
| 230 | iio_device_free(indio_dev); |
| 231 | return ret; |
| 232 | } |
| 233 | |
Greg Kroah-Hartman | fc52692 | 2012-12-21 13:21:43 -0800 | [diff] [blame] | 234 | static int lp8788_adc_remove(struct platform_device *pdev) |
Kim, Milo | f0347c3 | 2012-09-17 10:35:00 +0100 | [diff] [blame] | 235 | { |
| 236 | struct iio_dev *indio_dev = platform_get_drvdata(pdev); |
Kim, Milo | f0347c3 | 2012-09-17 10:35:00 +0100 | [diff] [blame] | 237 | |
| 238 | iio_device_unregister(indio_dev); |
Guenter Roeck | 6cb2afd | 2013-01-31 21:43:00 +0000 | [diff] [blame^] | 239 | iio_map_array_unregister(indio_dev); |
Kim, Milo | f0347c3 | 2012-09-17 10:35:00 +0100 | [diff] [blame] | 240 | iio_device_free(indio_dev); |
| 241 | |
| 242 | return 0; |
| 243 | } |
| 244 | |
| 245 | static struct platform_driver lp8788_adc_driver = { |
| 246 | .probe = lp8788_adc_probe, |
Greg Kroah-Hartman | fc52692 | 2012-12-21 13:21:43 -0800 | [diff] [blame] | 247 | .remove = lp8788_adc_remove, |
Kim, Milo | f0347c3 | 2012-09-17 10:35:00 +0100 | [diff] [blame] | 248 | .driver = { |
| 249 | .name = LP8788_DEV_ADC, |
| 250 | .owner = THIS_MODULE, |
| 251 | }, |
| 252 | }; |
| 253 | module_platform_driver(lp8788_adc_driver); |
| 254 | |
| 255 | MODULE_DESCRIPTION("Texas Instruments LP8788 ADC Driver"); |
| 256 | MODULE_AUTHOR("Milo Kim"); |
| 257 | MODULE_LICENSE("GPL"); |
| 258 | MODULE_ALIAS("platform:lp8788-adc"); |