cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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mcp4531.c (13940B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Industrial I/O driver for Microchip digital potentiometers
      4 * Copyright (c) 2015  Axentia Technologies AB
      5 * Author: Peter Rosin <peda@axentia.se>
      6 *
      7 * Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf
      8 *
      9 * DEVID	#Wipers	#Positions	Resistor Opts (kOhm)	i2c address
     10 * mcp4531	1	129		5, 10, 50, 100          010111x
     11 * mcp4532	1	129		5, 10, 50, 100          01011xx
     12 * mcp4541	1	129		5, 10, 50, 100          010111x
     13 * mcp4542	1	129		5, 10, 50, 100          01011xx
     14 * mcp4551	1	257		5, 10, 50, 100          010111x
     15 * mcp4552	1	257		5, 10, 50, 100          01011xx
     16 * mcp4561	1	257		5, 10, 50, 100          010111x
     17 * mcp4562	1	257		5, 10, 50, 100          01011xx
     18 * mcp4631	2	129		5, 10, 50, 100          0101xxx
     19 * mcp4632	2	129		5, 10, 50, 100          01011xx
     20 * mcp4641	2	129		5, 10, 50, 100          0101xxx
     21 * mcp4642	2	129		5, 10, 50, 100          01011xx
     22 * mcp4651	2	257		5, 10, 50, 100          0101xxx
     23 * mcp4652	2	257		5, 10, 50, 100          01011xx
     24 * mcp4661	2	257		5, 10, 50, 100          0101xxx
     25 * mcp4662	2	257		5, 10, 50, 100          01011xx
     26 */
     27
     28#include <linux/module.h>
     29#include <linux/i2c.h>
     30#include <linux/err.h>
     31#include <linux/mod_devicetable.h>
     32#include <linux/property.h>
     33
     34#include <linux/iio/iio.h>
     35
     36struct mcp4531_cfg {
     37	int wipers;
     38	int avail[3];
     39	int kohms;
     40};
     41
     42enum mcp4531_type {
     43	MCP453x_502,
     44	MCP453x_103,
     45	MCP453x_503,
     46	MCP453x_104,
     47	MCP454x_502,
     48	MCP454x_103,
     49	MCP454x_503,
     50	MCP454x_104,
     51	MCP455x_502,
     52	MCP455x_103,
     53	MCP455x_503,
     54	MCP455x_104,
     55	MCP456x_502,
     56	MCP456x_103,
     57	MCP456x_503,
     58	MCP456x_104,
     59	MCP463x_502,
     60	MCP463x_103,
     61	MCP463x_503,
     62	MCP463x_104,
     63	MCP464x_502,
     64	MCP464x_103,
     65	MCP464x_503,
     66	MCP464x_104,
     67	MCP465x_502,
     68	MCP465x_103,
     69	MCP465x_503,
     70	MCP465x_104,
     71	MCP466x_502,
     72	MCP466x_103,
     73	MCP466x_503,
     74	MCP466x_104,
     75};
     76
     77static const struct mcp4531_cfg mcp4531_cfg[] = {
     78	[MCP453x_502] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =   5, },
     79	[MCP453x_103] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =  10, },
     80	[MCP453x_503] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =  50, },
     81	[MCP453x_104] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 100, },
     82	[MCP454x_502] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =   5, },
     83	[MCP454x_103] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =  10, },
     84	[MCP454x_503] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms =  50, },
     85	[MCP454x_104] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 100, },
     86	[MCP455x_502] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =   5, },
     87	[MCP455x_103] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =  10, },
     88	[MCP455x_503] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =  50, },
     89	[MCP455x_104] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 100, },
     90	[MCP456x_502] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =   5, },
     91	[MCP456x_103] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =  10, },
     92	[MCP456x_503] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms =  50, },
     93	[MCP456x_104] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 100, },
     94	[MCP463x_502] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =   5, },
     95	[MCP463x_103] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =  10, },
     96	[MCP463x_503] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =  50, },
     97	[MCP463x_104] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 100, },
     98	[MCP464x_502] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =   5, },
     99	[MCP464x_103] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =  10, },
    100	[MCP464x_503] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms =  50, },
    101	[MCP464x_104] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 100, },
    102	[MCP465x_502] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =   5, },
    103	[MCP465x_103] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =  10, },
    104	[MCP465x_503] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =  50, },
    105	[MCP465x_104] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 100, },
    106	[MCP466x_502] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =   5, },
    107	[MCP466x_103] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =  10, },
    108	[MCP466x_503] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms =  50, },
    109	[MCP466x_104] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 100, },
    110};
    111
    112#define MCP4531_WRITE (0 << 2)
    113#define MCP4531_INCR  (1 << 2)
    114#define MCP4531_DECR  (2 << 2)
    115#define MCP4531_READ  (3 << 2)
    116
    117#define MCP4531_WIPER_SHIFT (4)
    118
    119struct mcp4531_data {
    120	struct i2c_client *client;
    121	const struct mcp4531_cfg *cfg;
    122};
    123
    124#define MCP4531_CHANNEL(ch) {						\
    125	.type = IIO_RESISTANCE,						\
    126	.indexed = 1,							\
    127	.output = 1,							\
    128	.channel = (ch),						\
    129	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
    130	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),		\
    131	.info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_RAW),	\
    132}
    133
    134static const struct iio_chan_spec mcp4531_channels[] = {
    135	MCP4531_CHANNEL(0),
    136	MCP4531_CHANNEL(1),
    137};
    138
    139static int mcp4531_read_raw(struct iio_dev *indio_dev,
    140			    struct iio_chan_spec const *chan,
    141			    int *val, int *val2, long mask)
    142{
    143	struct mcp4531_data *data = iio_priv(indio_dev);
    144	int address = chan->channel << MCP4531_WIPER_SHIFT;
    145	s32 ret;
    146
    147	switch (mask) {
    148	case IIO_CHAN_INFO_RAW:
    149		ret = i2c_smbus_read_word_swapped(data->client,
    150						  MCP4531_READ | address);
    151		if (ret < 0)
    152			return ret;
    153		*val = ret;
    154		return IIO_VAL_INT;
    155	case IIO_CHAN_INFO_SCALE:
    156		*val = 1000 * data->cfg->kohms;
    157		*val2 = data->cfg->avail[2];
    158		return IIO_VAL_FRACTIONAL;
    159	}
    160
    161	return -EINVAL;
    162}
    163
    164static int mcp4531_read_avail(struct iio_dev *indio_dev,
    165			      struct iio_chan_spec const *chan,
    166			      const int **vals, int *type, int *length,
    167			      long mask)
    168{
    169	struct mcp4531_data *data = iio_priv(indio_dev);
    170
    171	switch (mask) {
    172	case IIO_CHAN_INFO_RAW:
    173		*length = ARRAY_SIZE(data->cfg->avail);
    174		*vals = data->cfg->avail;
    175		*type = IIO_VAL_INT;
    176		return IIO_AVAIL_RANGE;
    177	}
    178
    179	return -EINVAL;
    180}
    181
    182static int mcp4531_write_raw(struct iio_dev *indio_dev,
    183			     struct iio_chan_spec const *chan,
    184			     int val, int val2, long mask)
    185{
    186	struct mcp4531_data *data = iio_priv(indio_dev);
    187	int address = chan->channel << MCP4531_WIPER_SHIFT;
    188
    189	switch (mask) {
    190	case IIO_CHAN_INFO_RAW:
    191		if (val > data->cfg->avail[2] || val < 0)
    192			return -EINVAL;
    193		break;
    194	default:
    195		return -EINVAL;
    196	}
    197
    198	return i2c_smbus_write_byte_data(data->client,
    199					 MCP4531_WRITE | address | (val >> 8),
    200					 val & 0xff);
    201}
    202
    203static const struct iio_info mcp4531_info = {
    204	.read_raw = mcp4531_read_raw,
    205	.read_avail = mcp4531_read_avail,
    206	.write_raw = mcp4531_write_raw,
    207};
    208
    209static const struct i2c_device_id mcp4531_id[] = {
    210	{ "mcp4531-502", MCP453x_502 },
    211	{ "mcp4531-103", MCP453x_103 },
    212	{ "mcp4531-503", MCP453x_503 },
    213	{ "mcp4531-104", MCP453x_104 },
    214	{ "mcp4532-502", MCP453x_502 },
    215	{ "mcp4532-103", MCP453x_103 },
    216	{ "mcp4532-503", MCP453x_503 },
    217	{ "mcp4532-104", MCP453x_104 },
    218	{ "mcp4541-502", MCP454x_502 },
    219	{ "mcp4541-103", MCP454x_103 },
    220	{ "mcp4541-503", MCP454x_503 },
    221	{ "mcp4541-104", MCP454x_104 },
    222	{ "mcp4542-502", MCP454x_502 },
    223	{ "mcp4542-103", MCP454x_103 },
    224	{ "mcp4542-503", MCP454x_503 },
    225	{ "mcp4542-104", MCP454x_104 },
    226	{ "mcp4551-502", MCP455x_502 },
    227	{ "mcp4551-103", MCP455x_103 },
    228	{ "mcp4551-503", MCP455x_503 },
    229	{ "mcp4551-104", MCP455x_104 },
    230	{ "mcp4552-502", MCP455x_502 },
    231	{ "mcp4552-103", MCP455x_103 },
    232	{ "mcp4552-503", MCP455x_503 },
    233	{ "mcp4552-104", MCP455x_104 },
    234	{ "mcp4561-502", MCP456x_502 },
    235	{ "mcp4561-103", MCP456x_103 },
    236	{ "mcp4561-503", MCP456x_503 },
    237	{ "mcp4561-104", MCP456x_104 },
    238	{ "mcp4562-502", MCP456x_502 },
    239	{ "mcp4562-103", MCP456x_103 },
    240	{ "mcp4562-503", MCP456x_503 },
    241	{ "mcp4562-104", MCP456x_104 },
    242	{ "mcp4631-502", MCP463x_502 },
    243	{ "mcp4631-103", MCP463x_103 },
    244	{ "mcp4631-503", MCP463x_503 },
    245	{ "mcp4631-104", MCP463x_104 },
    246	{ "mcp4632-502", MCP463x_502 },
    247	{ "mcp4632-103", MCP463x_103 },
    248	{ "mcp4632-503", MCP463x_503 },
    249	{ "mcp4632-104", MCP463x_104 },
    250	{ "mcp4641-502", MCP464x_502 },
    251	{ "mcp4641-103", MCP464x_103 },
    252	{ "mcp4641-503", MCP464x_503 },
    253	{ "mcp4641-104", MCP464x_104 },
    254	{ "mcp4642-502", MCP464x_502 },
    255	{ "mcp4642-103", MCP464x_103 },
    256	{ "mcp4642-503", MCP464x_503 },
    257	{ "mcp4642-104", MCP464x_104 },
    258	{ "mcp4651-502", MCP465x_502 },
    259	{ "mcp4651-103", MCP465x_103 },
    260	{ "mcp4651-503", MCP465x_503 },
    261	{ "mcp4651-104", MCP465x_104 },
    262	{ "mcp4652-502", MCP465x_502 },
    263	{ "mcp4652-103", MCP465x_103 },
    264	{ "mcp4652-503", MCP465x_503 },
    265	{ "mcp4652-104", MCP465x_104 },
    266	{ "mcp4661-502", MCP466x_502 },
    267	{ "mcp4661-103", MCP466x_103 },
    268	{ "mcp4661-503", MCP466x_503 },
    269	{ "mcp4661-104", MCP466x_104 },
    270	{ "mcp4662-502", MCP466x_502 },
    271	{ "mcp4662-103", MCP466x_103 },
    272	{ "mcp4662-503", MCP466x_503 },
    273	{ "mcp4662-104", MCP466x_104 },
    274	{}
    275};
    276MODULE_DEVICE_TABLE(i2c, mcp4531_id);
    277
    278#define MCP4531_COMPATIBLE(of_compatible, cfg) {	\
    279			.compatible = of_compatible,	\
    280			.data = &mcp4531_cfg[cfg],	\
    281}
    282
    283static const struct of_device_id mcp4531_of_match[] = {
    284	MCP4531_COMPATIBLE("microchip,mcp4531-502", MCP453x_502),
    285	MCP4531_COMPATIBLE("microchip,mcp4531-103", MCP453x_103),
    286	MCP4531_COMPATIBLE("microchip,mcp4531-503", MCP453x_503),
    287	MCP4531_COMPATIBLE("microchip,mcp4531-104", MCP453x_104),
    288	MCP4531_COMPATIBLE("microchip,mcp4532-502", MCP453x_502),
    289	MCP4531_COMPATIBLE("microchip,mcp4532-103", MCP453x_103),
    290	MCP4531_COMPATIBLE("microchip,mcp4532-503", MCP453x_503),
    291	MCP4531_COMPATIBLE("microchip,mcp4532-104", MCP453x_104),
    292	MCP4531_COMPATIBLE("microchip,mcp4541-502", MCP454x_502),
    293	MCP4531_COMPATIBLE("microchip,mcp4541-103", MCP454x_103),
    294	MCP4531_COMPATIBLE("microchip,mcp4541-503", MCP454x_503),
    295	MCP4531_COMPATIBLE("microchip,mcp4541-104", MCP454x_104),
    296	MCP4531_COMPATIBLE("microchip,mcp4542-502", MCP454x_502),
    297	MCP4531_COMPATIBLE("microchip,mcp4542-103", MCP454x_103),
    298	MCP4531_COMPATIBLE("microchip,mcp4542-503", MCP454x_503),
    299	MCP4531_COMPATIBLE("microchip,mcp4542-104", MCP454x_104),
    300	MCP4531_COMPATIBLE("microchip,mcp4551-502", MCP455x_502),
    301	MCP4531_COMPATIBLE("microchip,mcp4551-103", MCP455x_103),
    302	MCP4531_COMPATIBLE("microchip,mcp4551-503", MCP455x_503),
    303	MCP4531_COMPATIBLE("microchip,mcp4551-104", MCP455x_104),
    304	MCP4531_COMPATIBLE("microchip,mcp4552-502", MCP455x_502),
    305	MCP4531_COMPATIBLE("microchip,mcp4552-103", MCP455x_103),
    306	MCP4531_COMPATIBLE("microchip,mcp4552-503", MCP455x_503),
    307	MCP4531_COMPATIBLE("microchip,mcp4552-104", MCP455x_104),
    308	MCP4531_COMPATIBLE("microchip,mcp4561-502", MCP456x_502),
    309	MCP4531_COMPATIBLE("microchip,mcp4561-103", MCP456x_103),
    310	MCP4531_COMPATIBLE("microchip,mcp4561-503", MCP456x_503),
    311	MCP4531_COMPATIBLE("microchip,mcp4561-104", MCP456x_104),
    312	MCP4531_COMPATIBLE("microchip,mcp4562-502", MCP456x_502),
    313	MCP4531_COMPATIBLE("microchip,mcp4562-103", MCP456x_103),
    314	MCP4531_COMPATIBLE("microchip,mcp4562-503", MCP456x_503),
    315	MCP4531_COMPATIBLE("microchip,mcp4562-104", MCP456x_104),
    316	MCP4531_COMPATIBLE("microchip,mcp4631-502", MCP463x_502),
    317	MCP4531_COMPATIBLE("microchip,mcp4631-103", MCP463x_103),
    318	MCP4531_COMPATIBLE("microchip,mcp4631-503", MCP463x_503),
    319	MCP4531_COMPATIBLE("microchip,mcp4631-104", MCP463x_104),
    320	MCP4531_COMPATIBLE("microchip,mcp4632-502", MCP463x_502),
    321	MCP4531_COMPATIBLE("microchip,mcp4632-103", MCP463x_103),
    322	MCP4531_COMPATIBLE("microchip,mcp4632-503", MCP463x_503),
    323	MCP4531_COMPATIBLE("microchip,mcp4632-104", MCP463x_104),
    324	MCP4531_COMPATIBLE("microchip,mcp4641-502", MCP464x_502),
    325	MCP4531_COMPATIBLE("microchip,mcp4641-103", MCP464x_103),
    326	MCP4531_COMPATIBLE("microchip,mcp4641-503", MCP464x_503),
    327	MCP4531_COMPATIBLE("microchip,mcp4641-104", MCP464x_104),
    328	MCP4531_COMPATIBLE("microchip,mcp4642-502", MCP464x_502),
    329	MCP4531_COMPATIBLE("microchip,mcp4642-103", MCP464x_103),
    330	MCP4531_COMPATIBLE("microchip,mcp4642-503", MCP464x_503),
    331	MCP4531_COMPATIBLE("microchip,mcp4642-104", MCP464x_104),
    332	MCP4531_COMPATIBLE("microchip,mcp4651-502", MCP465x_502),
    333	MCP4531_COMPATIBLE("microchip,mcp4651-103", MCP465x_103),
    334	MCP4531_COMPATIBLE("microchip,mcp4651-503", MCP465x_503),
    335	MCP4531_COMPATIBLE("microchip,mcp4651-104", MCP465x_104),
    336	MCP4531_COMPATIBLE("microchip,mcp4652-502", MCP465x_502),
    337	MCP4531_COMPATIBLE("microchip,mcp4652-103", MCP465x_103),
    338	MCP4531_COMPATIBLE("microchip,mcp4652-503", MCP465x_503),
    339	MCP4531_COMPATIBLE("microchip,mcp4652-104", MCP465x_104),
    340	MCP4531_COMPATIBLE("microchip,mcp4661-502", MCP466x_502),
    341	MCP4531_COMPATIBLE("microchip,mcp4661-103", MCP466x_103),
    342	MCP4531_COMPATIBLE("microchip,mcp4661-503", MCP466x_503),
    343	MCP4531_COMPATIBLE("microchip,mcp4661-104", MCP466x_104),
    344	MCP4531_COMPATIBLE("microchip,mcp4662-502", MCP466x_502),
    345	MCP4531_COMPATIBLE("microchip,mcp4662-103", MCP466x_103),
    346	MCP4531_COMPATIBLE("microchip,mcp4662-503", MCP466x_503),
    347	MCP4531_COMPATIBLE("microchip,mcp4662-104", MCP466x_104),
    348	{ /* sentinel */ }
    349};
    350MODULE_DEVICE_TABLE(of, mcp4531_of_match);
    351
    352static int mcp4531_probe(struct i2c_client *client)
    353{
    354	struct device *dev = &client->dev;
    355	struct mcp4531_data *data;
    356	struct iio_dev *indio_dev;
    357
    358	if (!i2c_check_functionality(client->adapter,
    359				     I2C_FUNC_SMBUS_WORD_DATA)) {
    360		dev_err(dev, "SMBUS Word Data not supported\n");
    361		return -EOPNOTSUPP;
    362	}
    363
    364	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
    365	if (!indio_dev)
    366		return -ENOMEM;
    367	data = iio_priv(indio_dev);
    368	i2c_set_clientdata(client, indio_dev);
    369	data->client = client;
    370
    371	data->cfg = device_get_match_data(dev);
    372	if (!data->cfg)
    373		data->cfg = &mcp4531_cfg[i2c_match_id(mcp4531_id, client)->driver_data];
    374
    375	indio_dev->info = &mcp4531_info;
    376	indio_dev->channels = mcp4531_channels;
    377	indio_dev->num_channels = data->cfg->wipers;
    378	indio_dev->name = client->name;
    379
    380	return devm_iio_device_register(dev, indio_dev);
    381}
    382
    383static struct i2c_driver mcp4531_driver = {
    384	.driver = {
    385		.name	= "mcp4531",
    386		.of_match_table = mcp4531_of_match,
    387	},
    388	.probe_new	= mcp4531_probe,
    389	.id_table	= mcp4531_id,
    390};
    391
    392module_i2c_driver(mcp4531_driver);
    393
    394MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
    395MODULE_DESCRIPTION("MCP4531 digital potentiometer");
    396MODULE_LICENSE("GPL v2");