platform/mellanox: Introduce support for Mellanox register access driver (5ec4a8ac) · Commits · 戴 / test

drivers/platform/mellanox/Kconfig

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Original line number	Diff line number	Diff line
		@@ -23,4 +23,15 @@ config MLXREG_HOTPLUG
		This driver handles hot-plug events for the power suppliers, power
		cables and fans on the wide range Mellanox IB and Ethernet systems.

		config MLXREG_IO
		tristate "Mellanox platform register access driver support"
		depends on REGMAP
		depends on HWMON
		help
		This driver allows access to Mellanox programmable device register
		space through sysfs interface. The sets of registers for sysfs access
		are defined per system type bases and include the registers related
		to system resets operation, system reset causes monitoring and some
		kinds of mux selection.

		endif # MELLANOX_PLATFORM

drivers/platform/mellanox/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -4,3 +4,4 @@
		# Mellanox Platform-Specific Drivers
		#
		obj-$(CONFIG_MLXREG_HOTPLUG) += mlxreg-hotplug.o
		obj-$(CONFIG_MLXREG_IO) += mlxreg-io.o

drivers/platform/mellanox/mlxreg-io.c

0 → 100644

+245 −0

Original line number	Diff line number	Diff line
		// 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;
		*/
		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];
		};

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

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

		/*
		* There are three kinds of attributes: single bit, full register's
		* bits and bit sequence. 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, field mask indicates which bits are related and
		* field bit is set to the first bit number (from 1 to 32) is the bit
		* sequence.
		*/
		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;
		}
		}

		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, &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,
		&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_kzalloc(&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;

		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");

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