drivers/platform/mellanox/mlxreg-io.c - linux - Git at Google

 // 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);
 		}
 	}

 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, len, &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");
	// 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);
	}
	}

	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, len, &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");