drivers/iio/adc/gehc-pmc-adc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * The GE HealthCare PMC ADC is a 16-Channel (Voltage and current), 16-Bit
   4  * ADC with an I2C Interface.
   5  *
   6  * Copyright (C) 2024, GE HealthCare
   7  *
   8  * Authors:
   9  * Herve Codina <herve.codina@bootlin.com>
  10  */
  11 #include <dt-bindings/iio/adc/gehc,pmc-adc.h>
  12 #include <linux/bitops.h>
  13 #include <linux/clk.h>
  14 #include <linux/i2c.h>
  15 #include <linux/iio/iio.h>
  16 #include <linux/module.h>
  17 #include <linux/regulator/consumer.h>
  18 #include <linux/slab.h>
  19
  20 struct pmc_adc {
  21         struct i2c_client *client;
  22 };
  23
  24 #define PMC_ADC_CMD_REQUEST_PROTOCOL_VERSION    0x01
  25 #define PMC_ADC_CMD_READ_VOLTAGE(_ch)           (0x10 | (_ch))
  26 #define PMC_ADC_CMD_READ_CURRENT(_ch)           (0x20 | (_ch))
  27
  28 #define PMC_ADC_VOLTAGE_CHANNEL(_ch, _ds_name) {                        \
  29         .type = IIO_VOLTAGE,                                            \
  30         .indexed = 1,                                                   \
  31         .channel = (_ch),                                               \
  32         .address = PMC_ADC_CMD_READ_VOLTAGE(_ch),                       \
  33         .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),             \
  34         .datasheet_name = (_ds_name),                                   \
  35 }
  36
  37 #define PMC_ADC_CURRENT_CHANNEL(_ch, _ds_name) {                        \
  38         .type = IIO_CURRENT,                                            \
  39         .indexed = 1,                                                   \
  40         .channel = (_ch),                                               \
  41         .address = PMC_ADC_CMD_READ_CURRENT(_ch),                       \
  42         .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),             \
  43         .datasheet_name = (_ds_name),                                   \
  44 }
  45
  46 static const struct iio_chan_spec pmc_adc_channels[] = {
  47         PMC_ADC_VOLTAGE_CHANNEL(0, "CH0_V"),
  48         PMC_ADC_VOLTAGE_CHANNEL(1, "CH1_V"),
  49         PMC_ADC_VOLTAGE_CHANNEL(2, "CH2_V"),
  50         PMC_ADC_VOLTAGE_CHANNEL(3, "CH3_V"),
  51         PMC_ADC_VOLTAGE_CHANNEL(4, "CH4_V"),
  52         PMC_ADC_VOLTAGE_CHANNEL(5, "CH5_V"),
  53         PMC_ADC_VOLTAGE_CHANNEL(6, "CH6_V"),
  54         PMC_ADC_VOLTAGE_CHANNEL(7, "CH7_V"),
  55         PMC_ADC_VOLTAGE_CHANNEL(8, "CH8_V"),
  56         PMC_ADC_VOLTAGE_CHANNEL(9, "CH9_V"),
  57         PMC_ADC_VOLTAGE_CHANNEL(10, "CH10_V"),
  58         PMC_ADC_VOLTAGE_CHANNEL(11, "CH11_V"),
  59         PMC_ADC_VOLTAGE_CHANNEL(12, "CH12_V"),
  60         PMC_ADC_VOLTAGE_CHANNEL(13, "CH13_V"),
  61         PMC_ADC_VOLTAGE_CHANNEL(14, "CH14_V"),
  62         PMC_ADC_VOLTAGE_CHANNEL(15, "CH15_V"),
  63
  64         PMC_ADC_CURRENT_CHANNEL(0, "CH0_I"),
  65         PMC_ADC_CURRENT_CHANNEL(1, "CH1_I"),
  66         PMC_ADC_CURRENT_CHANNEL(2, "CH2_I"),
  67         PMC_ADC_CURRENT_CHANNEL(3, "CH3_I"),
  68         PMC_ADC_CURRENT_CHANNEL(4, "CH4_I"),
  69         PMC_ADC_CURRENT_CHANNEL(5, "CH5_I"),
  70         PMC_ADC_CURRENT_CHANNEL(6, "CH6_I"),
  71         PMC_ADC_CURRENT_CHANNEL(7, "CH7_I"),
  72         PMC_ADC_CURRENT_CHANNEL(8, "CH8_I"),
  73         PMC_ADC_CURRENT_CHANNEL(9, "CH9_I"),
  74         PMC_ADC_CURRENT_CHANNEL(10, "CH10_I"),
  75         PMC_ADC_CURRENT_CHANNEL(11, "CH11_I"),
  76         PMC_ADC_CURRENT_CHANNEL(12, "CH12_I"),
  77         PMC_ADC_CURRENT_CHANNEL(13, "CH13_I"),
  78         PMC_ADC_CURRENT_CHANNEL(14, "CH14_I"),
  79         PMC_ADC_CURRENT_CHANNEL(15, "CH15_I"),
  80 };
  81
  82 static int pmc_adc_read_raw_ch(struct pmc_adc *pmc_adc, u8 cmd, int *val)
  83 {
  84         s32 ret;
  85
  86         ret = i2c_smbus_read_word_swapped(pmc_adc->client, cmd);
  87         if (ret < 0) {
  88                 dev_err(&pmc_adc->client->dev, "i2c read word failed (%d)\n", ret);
  89                 return ret;
  90         }
  91
  92         *val = sign_extend32(ret, 15);
  93         return 0;
  94 }
  95
  96 static int pmc_adc_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
  97                             int *val, int *val2, long mask)
  98 {
  99         struct pmc_adc *pmc_adc = iio_priv(indio_dev);
 100         int ret;
 101
 102         switch (mask) {
 103         case IIO_CHAN_INFO_PROCESSED:
 104                 /* Values are directly read in mV or mA */
 105                 ret = pmc_adc_read_raw_ch(pmc_adc, chan->address, val);
 106                 if (ret)
 107                         return ret;
 108                 return IIO_VAL_INT;
 109         }
 110
 111         return -EINVAL;
 112 }
 113
 114 static int pmc_adc_fwnode_xlate(struct iio_dev *indio_dev,
 115                                 const struct fwnode_reference_args *iiospec)
 116 {
 117         enum iio_chan_type expected_type;
 118         unsigned int i;
 119
 120         /*
 121          * args[0]: Acquisition type (i.e. voltage or current)
 122          * args[1]: PMC ADC channel number
 123          */
 124         if (iiospec->nargs != 2)
 125                 return -EINVAL;
 126
 127         switch (iiospec->args[0]) {
 128         case GEHC_PMC_ADC_VOLTAGE:
 129                 expected_type = IIO_VOLTAGE;
 130                 break;
 131         case GEHC_PMC_ADC_CURRENT:
 132                 expected_type = IIO_CURRENT;
 133                 break;
 134         default:
 135                 dev_err(&indio_dev->dev, "Invalid channel type %llu\n",
 136                         iiospec->args[0]);
 137                 return -EINVAL;
 138         }
 139
 140         for (i = 0; i < indio_dev->num_channels; i++)
 141                 if (indio_dev->channels[i].type == expected_type &&
 142                     indio_dev->channels[i].channel == iiospec->args[1])
 143                         return i;
 144
 145         dev_err(&indio_dev->dev, "Invalid channel type %llu number %llu\n",
 146                 iiospec->args[0], iiospec->args[1]);
 147         return -EINVAL;
 148 }
 149
 150 static const struct iio_info pmc_adc_info = {
 151         .read_raw = pmc_adc_read_raw,
 152         .fwnode_xlate = pmc_adc_fwnode_xlate,
 153 };
 154
 155 static const char *const pmc_adc_regulator_names[] = {
 156         "vdd",
 157         "vdda",
 158         "vddio",
 159         "vref",
 160 };
 161
 162 static int pmc_adc_probe(struct i2c_client *client)
 163 {
 164         struct iio_dev *indio_dev;
 165         struct pmc_adc *pmc_adc;
 166         struct clk *clk;
 167         s32 val;
 168         int ret;
 169
 170         ret = devm_regulator_bulk_get_enable(&client->dev, ARRAY_SIZE(pmc_adc_regulator_names),
 171                                              pmc_adc_regulator_names);
 172         if (ret)
 173                 return dev_err_probe(&client->dev, ret, "Failed to get regulators\n");
 174
 175         clk = devm_clk_get_optional_enabled(&client->dev, "osc");
 176         if (IS_ERR(clk))
 177                 return dev_err_probe(&client->dev, PTR_ERR(clk), "Failed to get osc clock\n");
 178
 179         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*pmc_adc));
 180         if (!indio_dev)
 181                 return -ENOMEM;
 182
 183         pmc_adc = iio_priv(indio_dev);
 184         pmc_adc->client = client;
 185
 186         val = i2c_smbus_read_byte_data(pmc_adc->client, PMC_ADC_CMD_REQUEST_PROTOCOL_VERSION);
 187         if (val < 0)
 188                 return dev_err_probe(&client->dev, val, "Failed to get protocol version\n");
 189
 190         if (val != 0x01)
 191                 return dev_err_probe(&client->dev, -EINVAL,
 192                                      "Unsupported protocol version 0x%02x\n", val);
 193
 194         indio_dev->name = "pmc_adc";
 195         indio_dev->info = &pmc_adc_info;
 196         indio_dev->modes = INDIO_DIRECT_MODE;
 197         indio_dev->channels = pmc_adc_channels;
 198         indio_dev->num_channels = ARRAY_SIZE(pmc_adc_channels);
 199
 200         return devm_iio_device_register(&client->dev, indio_dev);
 201 }
 202
 203 static const struct of_device_id pmc_adc_of_match[] = {
 204         { .compatible = "gehc,pmc-adc"},
 205         { }
 206 };
 207 MODULE_DEVICE_TABLE(of, pmc_adc_of_match);
 208
 209 static const struct i2c_device_id pmc_adc_id_table[] = {
 210         { "pmc-adc" },
 211         { }
 212 };
 213 MODULE_DEVICE_TABLE(i2c, pmc_adc_id_table);
 214
 215 static struct i2c_driver pmc_adc_i2c_driver = {
 216         .driver  = {
 217                 .name = "pmc-adc",
 218                 .of_match_table = pmc_adc_of_match,
 219         },
 220         .id_table = pmc_adc_id_table,
 221         .probe  = pmc_adc_probe,
 222 };
 223
 224 module_i2c_driver(pmc_adc_i2c_driver);
 225
 226 MODULE_AUTHOR("Herve Codina <herve.codina@bootlin.com>");
 227 MODULE_DESCRIPTION("GE HealthCare PMC ADC driver");
 228 MODULE_LICENSE("GPL");