| // 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, ®val); |
| 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, |
| ®val); |
| 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; |
| |
| 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"); |