.. | .. |
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| 1 | +// SPDX-License-Identifier: GPL-2.0-only |
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1 | 2 | /* |
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2 | 3 | * ltc2497.c - Driver for Analog Devices/Linear Technology LTC2497 ADC |
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3 | 4 | * |
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4 | 5 | * Copyright (C) 2017 Analog Devices Inc. |
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5 | 6 | * |
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6 | | - * Licensed under the GPL-2. |
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7 | | - * |
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8 | 7 | * Datasheet: http://cds.linear.com/docs/en/datasheet/2497fd.pdf |
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9 | 8 | */ |
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10 | 9 | |
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11 | | -#include <linux/delay.h> |
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12 | 10 | #include <linux/i2c.h> |
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13 | 11 | #include <linux/iio/iio.h> |
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14 | 12 | #include <linux/iio/driver.h> |
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15 | | -#include <linux/iio/sysfs.h> |
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16 | 13 | #include <linux/module.h> |
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17 | | -#include <linux/of.h> |
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18 | | -#include <linux/regulator/consumer.h> |
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| 14 | +#include <linux/mod_devicetable.h> |
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19 | 15 | |
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20 | | -#define LTC2497_ENABLE 0xA0 |
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21 | | -#define LTC2497_SGL BIT(4) |
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22 | | -#define LTC2497_DIFF 0 |
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23 | | -#define LTC2497_SIGN BIT(3) |
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24 | | -#define LTC2497_CONFIG_DEFAULT LTC2497_ENABLE |
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25 | | -#define LTC2497_CONVERSION_TIME_MS 150ULL |
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| 16 | +#include "ltc2497.h" |
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26 | 17 | |
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27 | | -struct ltc2497_st { |
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| 18 | +struct ltc2497_driverdata { |
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| 19 | + /* this must be the first member */ |
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| 20 | + struct ltc2497core_driverdata common_ddata; |
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28 | 21 | struct i2c_client *client; |
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29 | | - struct regulator *ref; |
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30 | | - ktime_t time_prev; |
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31 | | - u8 addr_prev; |
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32 | 22 | /* |
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33 | 23 | * DMA (thus cache coherency maintenance) requires the |
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34 | 24 | * transfer buffers to live in their own cache lines. |
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.. | .. |
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36 | 26 | __be32 buf ____cacheline_aligned; |
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37 | 27 | }; |
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38 | 28 | |
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39 | | -static int ltc2497_wait_conv(struct ltc2497_st *st) |
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| 29 | +static int ltc2497_result_and_measure(struct ltc2497core_driverdata *ddata, |
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| 30 | + u8 address, int *val) |
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40 | 31 | { |
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41 | | - s64 time_elapsed; |
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42 | | - |
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43 | | - time_elapsed = ktime_ms_delta(ktime_get(), st->time_prev); |
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44 | | - |
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45 | | - if (time_elapsed < LTC2497_CONVERSION_TIME_MS) { |
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46 | | - /* delay if conversion time not passed |
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47 | | - * since last read or write |
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48 | | - */ |
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49 | | - if (msleep_interruptible( |
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50 | | - LTC2497_CONVERSION_TIME_MS - time_elapsed)) |
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51 | | - return -ERESTARTSYS; |
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52 | | - |
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53 | | - return 0; |
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54 | | - } |
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55 | | - |
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56 | | - if (time_elapsed - LTC2497_CONVERSION_TIME_MS <= 0) { |
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57 | | - /* We're in automatic mode - |
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58 | | - * so the last reading is stil not outdated |
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59 | | - */ |
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60 | | - return 0; |
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61 | | - } |
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62 | | - |
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63 | | - return 1; |
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64 | | -} |
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65 | | - |
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66 | | -static int ltc2497_read(struct ltc2497_st *st, u8 address, int *val) |
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67 | | -{ |
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68 | | - struct i2c_client *client = st->client; |
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| 32 | + struct ltc2497_driverdata *st = |
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| 33 | + container_of(ddata, struct ltc2497_driverdata, common_ddata); |
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69 | 34 | int ret; |
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70 | 35 | |
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71 | | - ret = ltc2497_wait_conv(st); |
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72 | | - if (ret < 0) |
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73 | | - return ret; |
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74 | | - |
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75 | | - if (ret || st->addr_prev != address) { |
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76 | | - ret = i2c_smbus_write_byte(st->client, |
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77 | | - LTC2497_ENABLE | address); |
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78 | | - if (ret < 0) |
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| 36 | + if (val) { |
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| 37 | + ret = i2c_master_recv(st->client, (char *)&st->buf, 3); |
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| 38 | + if (ret < 0) { |
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| 39 | + dev_err(&st->client->dev, "i2c_master_recv failed\n"); |
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79 | 40 | return ret; |
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80 | | - st->addr_prev = address; |
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81 | | - if (msleep_interruptible(LTC2497_CONVERSION_TIME_MS)) |
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82 | | - return -ERESTARTSYS; |
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83 | | - } |
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84 | | - ret = i2c_master_recv(client, (char *)&st->buf, 3); |
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85 | | - if (ret < 0) { |
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86 | | - dev_err(&client->dev, "i2c_master_recv failed\n"); |
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87 | | - return ret; |
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88 | | - } |
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89 | | - st->time_prev = ktime_get(); |
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| 41 | + } |
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90 | 42 | |
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91 | | - /* convert and shift the result, |
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92 | | - * and finally convert from offset binary to signed integer |
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93 | | - */ |
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94 | | - *val = (be32_to_cpu(st->buf) >> 14) - (1 << 17); |
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| 43 | + *val = (be32_to_cpu(st->buf) >> 14) - (1 << 17); |
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95 | 44 | |
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| 45 | + /* |
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| 46 | + * The part started a new conversion at the end of the above i2c |
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| 47 | + * transfer, so if the address didn't change since the last call |
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| 48 | + * everything is fine and we can return early. |
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| 49 | + * If not (which should only happen when some sort of bulk |
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| 50 | + * conversion is implemented) we have to program the new |
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| 51 | + * address. Note that this probably fails as the conversion that |
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| 52 | + * was triggered above is like not complete yet and the two |
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| 53 | + * operations have to be done in a single transfer. |
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| 54 | + */ |
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| 55 | + if (ddata->addr_prev == address) |
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| 56 | + return 0; |
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| 57 | + } |
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| 58 | + |
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| 59 | + ret = i2c_smbus_write_byte(st->client, |
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| 60 | + LTC2497_ENABLE | address); |
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| 61 | + if (ret) |
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| 62 | + dev_err(&st->client->dev, "i2c transfer failed: %pe\n", |
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| 63 | + ERR_PTR(ret)); |
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96 | 64 | return ret; |
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97 | 65 | } |
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98 | | - |
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99 | | -static int ltc2497_read_raw(struct iio_dev *indio_dev, |
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100 | | - struct iio_chan_spec const *chan, |
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101 | | - int *val, int *val2, long mask) |
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102 | | -{ |
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103 | | - struct ltc2497_st *st = iio_priv(indio_dev); |
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104 | | - int ret; |
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105 | | - |
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106 | | - switch (mask) { |
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107 | | - case IIO_CHAN_INFO_RAW: |
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108 | | - mutex_lock(&indio_dev->mlock); |
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109 | | - ret = ltc2497_read(st, chan->address, val); |
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110 | | - mutex_unlock(&indio_dev->mlock); |
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111 | | - if (ret < 0) |
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112 | | - return ret; |
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113 | | - |
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114 | | - return IIO_VAL_INT; |
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115 | | - |
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116 | | - case IIO_CHAN_INFO_SCALE: |
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117 | | - ret = regulator_get_voltage(st->ref); |
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118 | | - if (ret < 0) |
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119 | | - return ret; |
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120 | | - |
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121 | | - *val = ret / 1000; |
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122 | | - *val2 = 17; |
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123 | | - |
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124 | | - return IIO_VAL_FRACTIONAL_LOG2; |
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125 | | - |
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126 | | - default: |
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127 | | - return -EINVAL; |
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128 | | - } |
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129 | | -} |
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130 | | - |
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131 | | -#define LTC2497_CHAN(_chan, _addr, _ds_name) { \ |
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132 | | - .type = IIO_VOLTAGE, \ |
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133 | | - .indexed = 1, \ |
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134 | | - .channel = (_chan), \ |
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135 | | - .address = (_addr | (_chan / 2) | ((_chan & 1) ? LTC2497_SIGN : 0)), \ |
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136 | | - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
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137 | | - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ |
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138 | | - .datasheet_name = (_ds_name), \ |
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139 | | -} |
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140 | | - |
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141 | | -#define LTC2497_CHAN_DIFF(_chan, _addr) { \ |
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142 | | - .type = IIO_VOLTAGE, \ |
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143 | | - .indexed = 1, \ |
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144 | | - .channel = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 1 : 0), \ |
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145 | | - .channel2 = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 0 : 1),\ |
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146 | | - .address = (_addr | _chan), \ |
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147 | | - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
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148 | | - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ |
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149 | | - .differential = 1, \ |
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150 | | -} |
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151 | | - |
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152 | | -static const struct iio_chan_spec ltc2497_channel[] = { |
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153 | | - LTC2497_CHAN(0, LTC2497_SGL, "CH0"), |
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154 | | - LTC2497_CHAN(1, LTC2497_SGL, "CH1"), |
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155 | | - LTC2497_CHAN(2, LTC2497_SGL, "CH2"), |
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156 | | - LTC2497_CHAN(3, LTC2497_SGL, "CH3"), |
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157 | | - LTC2497_CHAN(4, LTC2497_SGL, "CH4"), |
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158 | | - LTC2497_CHAN(5, LTC2497_SGL, "CH5"), |
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159 | | - LTC2497_CHAN(6, LTC2497_SGL, "CH6"), |
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160 | | - LTC2497_CHAN(7, LTC2497_SGL, "CH7"), |
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161 | | - LTC2497_CHAN(8, LTC2497_SGL, "CH8"), |
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162 | | - LTC2497_CHAN(9, LTC2497_SGL, "CH9"), |
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163 | | - LTC2497_CHAN(10, LTC2497_SGL, "CH10"), |
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164 | | - LTC2497_CHAN(11, LTC2497_SGL, "CH11"), |
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165 | | - LTC2497_CHAN(12, LTC2497_SGL, "CH12"), |
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166 | | - LTC2497_CHAN(13, LTC2497_SGL, "CH13"), |
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167 | | - LTC2497_CHAN(14, LTC2497_SGL, "CH14"), |
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168 | | - LTC2497_CHAN(15, LTC2497_SGL, "CH15"), |
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169 | | - LTC2497_CHAN_DIFF(0, LTC2497_DIFF), |
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170 | | - LTC2497_CHAN_DIFF(1, LTC2497_DIFF), |
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171 | | - LTC2497_CHAN_DIFF(2, LTC2497_DIFF), |
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172 | | - LTC2497_CHAN_DIFF(3, LTC2497_DIFF), |
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173 | | - LTC2497_CHAN_DIFF(4, LTC2497_DIFF), |
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174 | | - LTC2497_CHAN_DIFF(5, LTC2497_DIFF), |
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175 | | - LTC2497_CHAN_DIFF(6, LTC2497_DIFF), |
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176 | | - LTC2497_CHAN_DIFF(7, LTC2497_DIFF), |
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177 | | - LTC2497_CHAN_DIFF(0, LTC2497_DIFF | LTC2497_SIGN), |
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178 | | - LTC2497_CHAN_DIFF(1, LTC2497_DIFF | LTC2497_SIGN), |
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179 | | - LTC2497_CHAN_DIFF(2, LTC2497_DIFF | LTC2497_SIGN), |
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180 | | - LTC2497_CHAN_DIFF(3, LTC2497_DIFF | LTC2497_SIGN), |
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181 | | - LTC2497_CHAN_DIFF(4, LTC2497_DIFF | LTC2497_SIGN), |
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182 | | - LTC2497_CHAN_DIFF(5, LTC2497_DIFF | LTC2497_SIGN), |
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183 | | - LTC2497_CHAN_DIFF(6, LTC2497_DIFF | LTC2497_SIGN), |
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184 | | - LTC2497_CHAN_DIFF(7, LTC2497_DIFF | LTC2497_SIGN), |
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185 | | -}; |
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186 | | - |
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187 | | -static const struct iio_info ltc2497_info = { |
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188 | | - .read_raw = ltc2497_read_raw, |
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189 | | -}; |
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190 | 66 | |
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191 | 67 | static int ltc2497_probe(struct i2c_client *client, |
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192 | 68 | const struct i2c_device_id *id) |
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193 | 69 | { |
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194 | 70 | struct iio_dev *indio_dev; |
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195 | | - struct ltc2497_st *st; |
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196 | | - struct iio_map *plat_data; |
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197 | | - int ret; |
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| 71 | + struct ltc2497_driverdata *st; |
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| 72 | + struct device *dev = &client->dev; |
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198 | 73 | |
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199 | 74 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C | |
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200 | 75 | I2C_FUNC_SMBUS_WRITE_BYTE)) |
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201 | 76 | return -EOPNOTSUPP; |
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202 | 77 | |
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203 | | - indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st)); |
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| 78 | + indio_dev = devm_iio_device_alloc(dev, sizeof(*st)); |
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204 | 79 | if (!indio_dev) |
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205 | 80 | return -ENOMEM; |
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206 | 81 | |
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207 | 82 | st = iio_priv(indio_dev); |
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208 | 83 | i2c_set_clientdata(client, indio_dev); |
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209 | 84 | st->client = client; |
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| 85 | + st->common_ddata.result_and_measure = ltc2497_result_and_measure; |
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210 | 86 | |
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211 | | - indio_dev->dev.parent = &client->dev; |
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212 | | - indio_dev->name = id->name; |
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213 | | - indio_dev->info = <c2497_info; |
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214 | | - indio_dev->modes = INDIO_DIRECT_MODE; |
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215 | | - indio_dev->channels = ltc2497_channel; |
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216 | | - indio_dev->num_channels = ARRAY_SIZE(ltc2497_channel); |
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217 | | - |
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218 | | - st->ref = devm_regulator_get(&client->dev, "vref"); |
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219 | | - if (IS_ERR(st->ref)) |
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220 | | - return PTR_ERR(st->ref); |
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221 | | - |
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222 | | - ret = regulator_enable(st->ref); |
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223 | | - if (ret < 0) |
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224 | | - return ret; |
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225 | | - |
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226 | | - if (client->dev.platform_data) { |
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227 | | - plat_data = ((struct iio_map *)client->dev.platform_data); |
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228 | | - ret = iio_map_array_register(indio_dev, plat_data); |
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229 | | - if (ret) { |
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230 | | - dev_err(&indio_dev->dev, "iio map err: %d\n", ret); |
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231 | | - goto err_regulator_disable; |
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232 | | - } |
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233 | | - } |
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234 | | - |
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235 | | - ret = i2c_smbus_write_byte(st->client, LTC2497_CONFIG_DEFAULT); |
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236 | | - if (ret < 0) |
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237 | | - goto err_array_unregister; |
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238 | | - |
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239 | | - st->addr_prev = LTC2497_CONFIG_DEFAULT; |
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240 | | - st->time_prev = ktime_get(); |
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241 | | - |
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242 | | - ret = iio_device_register(indio_dev); |
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243 | | - if (ret < 0) |
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244 | | - goto err_array_unregister; |
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245 | | - |
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246 | | - return 0; |
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247 | | - |
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248 | | -err_array_unregister: |
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249 | | - iio_map_array_unregister(indio_dev); |
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250 | | - |
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251 | | -err_regulator_disable: |
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252 | | - regulator_disable(st->ref); |
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253 | | - |
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254 | | - return ret; |
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| 87 | + return ltc2497core_probe(dev, indio_dev); |
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255 | 88 | } |
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256 | 89 | |
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257 | 90 | static int ltc2497_remove(struct i2c_client *client) |
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258 | 91 | { |
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259 | 92 | struct iio_dev *indio_dev = i2c_get_clientdata(client); |
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260 | | - struct ltc2497_st *st = iio_priv(indio_dev); |
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261 | 93 | |
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262 | | - iio_map_array_unregister(indio_dev); |
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263 | | - iio_device_unregister(indio_dev); |
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264 | | - regulator_disable(st->ref); |
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| 94 | + ltc2497core_remove(indio_dev); |
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265 | 95 | |
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266 | 96 | return 0; |
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267 | 97 | } |
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.. | .. |
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281 | 111 | static struct i2c_driver ltc2497_driver = { |
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282 | 112 | .driver = { |
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283 | 113 | .name = "ltc2497", |
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284 | | - .of_match_table = of_match_ptr(ltc2497_of_match), |
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| 114 | + .of_match_table = ltc2497_of_match, |
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285 | 115 | }, |
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286 | 116 | .probe = ltc2497_probe, |
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287 | 117 | .remove = ltc2497_remove, |
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