summaryrefslogtreecommitdiff
path: root/drivers/platform/mellanox/mlxreg-io.c
blob: a916cd89cbbeddf99272f26012a790d43ce08f7b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
// SPDX-License-Identifier: GPL-2.0+
/*
 * Mellanox register access driver
 *
 * Copyright (C) 2018 Mellanox Technologies
 * Copyright (C) 2018 Vadim Pasternak <vadimp@mellanox.com>
 */

#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_data/mlxreg.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

/* Attribute parameters. */
#define MLXREG_IO_ATT_SIZE	10
#define MLXREG_IO_ATT_NUM	48

/**
 * struct mlxreg_io_priv_data - driver's private data:
 *
 * @pdev: platform device;
 * @pdata: platform data;
 * @hwmon: hwmon device;
 * @mlxreg_io_attr: sysfs attributes array;
 * @mlxreg_io_dev_attr: sysfs sensor device attribute array;
 * @group: sysfs attribute group;
 * @groups: list of sysfs attribute group for hwmon registration;
 * @regsize: size of a register value;
 */
struct mlxreg_io_priv_data {
	struct platform_device *pdev;
	struct mlxreg_core_platform_data *pdata;
	struct device *hwmon;
	struct attribute *mlxreg_io_attr[MLXREG_IO_ATT_NUM + 1];
	struct sensor_device_attribute mlxreg_io_dev_attr[MLXREG_IO_ATT_NUM];
	struct attribute_group group;
	const struct attribute_group *groups[2];
	int regsize;
};

static int
mlxreg_io_get_reg(void *regmap, struct mlxreg_core_data *data, u32 in_val,
		  bool rw_flag, int regsize, u32 *regval)
{
	int i, val, ret;

	ret = regmap_read(regmap, data->reg, regval);
	if (ret)
		goto access_error;

	/*
	 * There are four kinds of attributes: single bit, full register's
	 * bits, bit sequence, bits in few registers For the first kind field
	 * mask indicates which bits are not related and field bit is set zero.
	 * For the second kind field mask is set to zero and field bit is set
	 * with all bits one. No special handling for such kind of attributes -
	 * pass value as is. For the third kind, the field mask indicates which
	 * bits are related and the field bit is set to the first bit number
	 * (from 1 to 32) is the bit sequence. For the fourth kind - the number
	 * of registers which should be read for getting an attribute are
	 * specified through 'data->regnum' field.
	 */
	if (!data->bit) {
		/* Single bit. */
		if (rw_flag) {
			/* For show: expose effective bit value as 0 or 1. */
			*regval = !!(*regval & ~data->mask);
		} else {
			/* For store: set effective bit value. */
			*regval &= data->mask;
			if (in_val)
				*regval |= ~data->mask;
		}
	} else if (data->mask) {
		/* Bit sequence. */
		if (rw_flag) {
			/* For show: mask and shift right. */
			*regval = ror32(*regval & data->mask, (data->bit - 1));
		} else {
			/* For store: shift to the position and mask. */
			in_val = rol32(in_val, data->bit - 1) & data->mask;
			/* Clear relevant bits and set them to new value. */
			*regval = (*regval & ~data->mask) | in_val;
		}
	} else {
		/*
		 * Some attributes could occupied few registers in case regmap
		 * bit size is 8 or 16. Compose such attributes from 'regnum'
		 * registers. Such attributes contain read-only data.
		 */
		for (i = 1; i < data->regnum; i++) {
			ret = regmap_read(regmap, data->reg + i, &val);
			if (ret)
				goto access_error;

			*regval |= rol32(val, regsize * i * 8);
		}
	}

access_error:
	return ret;
}

static ssize_t
mlxreg_io_attr_show(struct device *dev, struct device_attribute *attr,
		    char *buf)
{
	struct mlxreg_io_priv_data *priv = dev_get_drvdata(dev);
	int index = to_sensor_dev_attr(attr)->index;
	struct mlxreg_core_data *data = priv->pdata->data + index;
	u32 regval = 0;
	int ret;

	ret = mlxreg_io_get_reg(priv->pdata->regmap, data, 0, true,
				priv->regsize, &regval);
	if (ret)
		goto access_error;

	return sprintf(buf, "%u\n", regval);

access_error:
	return ret;
}

static ssize_t
mlxreg_io_attr_store(struct device *dev, struct device_attribute *attr,
		     const char *buf, size_t len)
{
	struct mlxreg_io_priv_data *priv = dev_get_drvdata(dev);
	int index = to_sensor_dev_attr(attr)->index;
	struct mlxreg_core_data *data = priv->pdata->data + index;
	u32 input_val, regval;
	int ret;

	if (len > MLXREG_IO_ATT_SIZE)
		return -EINVAL;

	/* Convert buffer to input value. */
	ret = kstrtou32(buf, 0, &input_val);
	if (ret)
		return ret;

	ret = mlxreg_io_get_reg(priv->pdata->regmap, data, input_val, false,
				priv->regsize, &regval);
	if (ret)
		goto access_error;

	ret = regmap_write(priv->pdata->regmap, data->reg, regval);
	if (ret)
		goto access_error;

	return len;

access_error:
	dev_err(&priv->pdev->dev, "Bus access error\n");
	return ret;
}

static struct device_attribute mlxreg_io_devattr_rw = {
	.show	= mlxreg_io_attr_show,
	.store	= mlxreg_io_attr_store,
};

static int mlxreg_io_attr_init(struct mlxreg_io_priv_data *priv)
{
	int i;

	priv->group.attrs = devm_kcalloc(&priv->pdev->dev,
					 priv->pdata->counter,
					 sizeof(struct attribute *),
					 GFP_KERNEL);
	if (!priv->group.attrs)
		return -ENOMEM;

	for (i = 0; i < priv->pdata->counter; i++) {
		priv->mlxreg_io_attr[i] =
				&priv->mlxreg_io_dev_attr[i].dev_attr.attr;
		memcpy(&priv->mlxreg_io_dev_attr[i].dev_attr,
		       &mlxreg_io_devattr_rw, sizeof(struct device_attribute));

		/* Set attribute name as a label. */
		priv->mlxreg_io_attr[i]->name =
				devm_kasprintf(&priv->pdev->dev, GFP_KERNEL,
					       priv->pdata->data[i].label);

		if (!priv->mlxreg_io_attr[i]->name) {
			dev_err(&priv->pdev->dev, "Memory allocation failed for sysfs attribute %d.\n",
				i + 1);
			return -ENOMEM;
		}

		priv->mlxreg_io_dev_attr[i].dev_attr.attr.mode =
						priv->pdata->data[i].mode;
		priv->mlxreg_io_dev_attr[i].dev_attr.attr.name =
					priv->mlxreg_io_attr[i]->name;
		priv->mlxreg_io_dev_attr[i].index = i;
		sysfs_attr_init(&priv->mlxreg_io_dev_attr[i].dev_attr.attr);
	}

	priv->group.attrs = priv->mlxreg_io_attr;
	priv->groups[0] = &priv->group;
	priv->groups[1] = NULL;

	return 0;
}

static int mlxreg_io_probe(struct platform_device *pdev)
{
	struct mlxreg_io_priv_data *priv;
	int err;

	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	priv->pdata = dev_get_platdata(&pdev->dev);
	if (!priv->pdata) {
		dev_err(&pdev->dev, "Failed to get platform data.\n");
		return -EINVAL;
	}

	priv->pdev = pdev;
	priv->regsize = regmap_get_val_bytes(priv->pdata->regmap);
	if (priv->regsize < 0)
		return priv->regsize;

	err = mlxreg_io_attr_init(priv);
	if (err) {
		dev_err(&priv->pdev->dev, "Failed to allocate attributes: %d\n",
			err);
		return err;
	}

	priv->hwmon = devm_hwmon_device_register_with_groups(&pdev->dev,
							     "mlxreg_io",
							      priv,
							      priv->groups);
	if (IS_ERR(priv->hwmon)) {
		dev_err(&pdev->dev, "Failed to register hwmon device %ld\n",
			PTR_ERR(priv->hwmon));
		return PTR_ERR(priv->hwmon);
	}

	dev_set_drvdata(&pdev->dev, priv);

	return 0;
}

static struct platform_driver mlxreg_io_driver = {
	.driver = {
	    .name = "mlxreg-io",
	},
	.probe = mlxreg_io_probe,
};

module_platform_driver(mlxreg_io_driver);

MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
MODULE_DESCRIPTION("Mellanox regmap I/O access driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:mlxreg-io");