diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/platform/mellanox/mlxreg-hotplug.c | 694 |
1 files changed, 694 insertions, 0 deletions
diff --git a/drivers/platform/mellanox/mlxreg-hotplug.c b/drivers/platform/mellanox/mlxreg-hotplug.c new file mode 100644 index 000000000..d52c821b8 --- /dev/null +++ b/drivers/platform/mellanox/mlxreg-hotplug.c @@ -0,0 +1,694 @@ +/* + * Copyright (c) 2016-2018 Mellanox Technologies. All rights reserved. + * Copyright (c) 2016-2018 Vadim Pasternak <vadimp@mellanox.com> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the names of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * Alternatively, this software may be distributed under the terms of the + * GNU General Public License ("GPL") version 2 as published by the Free + * Software Foundation. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include <linux/bitops.h> +#include <linux/device.h> +#include <linux/hwmon.h> +#include <linux/hwmon-sysfs.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/platform_data/mlxreg.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> +#include <linux/regmap.h> +#include <linux/workqueue.h> + +/* Offset of event and mask registers from status register. */ +#define MLXREG_HOTPLUG_EVENT_OFF 1 +#define MLXREG_HOTPLUG_MASK_OFF 2 +#define MLXREG_HOTPLUG_AGGR_MASK_OFF 1 + +/* ASIC good health mask. */ +#define MLXREG_HOTPLUG_GOOD_HEALTH_MASK 0x02 + +#define MLXREG_HOTPLUG_ATTRS_MAX 24 +#define MLXREG_HOTPLUG_NOT_ASSERT 3 + +/** + * struct mlxreg_hotplug_priv_data - platform private data: + * @irq: platform device interrupt number; + * @dev: basic device; + * @pdev: platform device; + * @plat: platform data; + * @regmap: register map handle; + * @dwork_irq: delayed work template; + * @lock: spin lock; + * @hwmon: hwmon device; + * @mlxreg_hotplug_attr: sysfs attributes array; + * @mlxreg_hotplug_dev_attr: sysfs sensor device attribute array; + * @group: sysfs attribute group; + * @groups: list of sysfs attribute group for hwmon registration; + * @cell: location of top aggregation interrupt register; + * @mask: top aggregation interrupt common mask; + * @aggr_cache: last value of aggregation register status; + * @after_probe: flag indication probing completion; + * @not_asserted: number of entries in workqueue with no signal assertion; + */ +struct mlxreg_hotplug_priv_data { + int irq; + struct device *dev; + struct platform_device *pdev; + struct mlxreg_hotplug_platform_data *plat; + struct regmap *regmap; + struct delayed_work dwork_irq; + spinlock_t lock; /* sync with interrupt */ + struct device *hwmon; + struct attribute *mlxreg_hotplug_attr[MLXREG_HOTPLUG_ATTRS_MAX + 1]; + struct sensor_device_attribute_2 + mlxreg_hotplug_dev_attr[MLXREG_HOTPLUG_ATTRS_MAX]; + struct attribute_group group; + const struct attribute_group *groups[2]; + u32 cell; + u32 mask; + u32 aggr_cache; + bool after_probe; + u8 not_asserted; +}; + +static int mlxreg_hotplug_device_create(struct mlxreg_hotplug_priv_data *priv, + struct mlxreg_core_data *data) +{ + struct mlxreg_core_hotplug_platform_data *pdata; + + /* Notify user by sending hwmon uevent. */ + kobject_uevent(&priv->hwmon->kobj, KOBJ_CHANGE); + + /* + * Return if adapter number is negative. It could be in case hotplug + * event is not associated with hotplug device. + */ + if (data->hpdev.nr < 0) + return 0; + + pdata = dev_get_platdata(&priv->pdev->dev); + data->hpdev.adapter = i2c_get_adapter(data->hpdev.nr + + pdata->shift_nr); + if (!data->hpdev.adapter) { + dev_err(priv->dev, "Failed to get adapter for bus %d\n", + data->hpdev.nr + pdata->shift_nr); + return -EFAULT; + } + + data->hpdev.client = i2c_new_device(data->hpdev.adapter, + data->hpdev.brdinfo); + if (!data->hpdev.client) { + dev_err(priv->dev, "Failed to create client %s at bus %d at addr 0x%02x\n", + data->hpdev.brdinfo->type, data->hpdev.nr + + pdata->shift_nr, data->hpdev.brdinfo->addr); + + i2c_put_adapter(data->hpdev.adapter); + data->hpdev.adapter = NULL; + return -EFAULT; + } + + return 0; +} + +static void +mlxreg_hotplug_device_destroy(struct mlxreg_hotplug_priv_data *priv, + struct mlxreg_core_data *data) +{ + /* Notify user by sending hwmon uevent. */ + kobject_uevent(&priv->hwmon->kobj, KOBJ_CHANGE); + + if (data->hpdev.client) { + i2c_unregister_device(data->hpdev.client); + data->hpdev.client = NULL; + } + + if (data->hpdev.adapter) { + i2c_put_adapter(data->hpdev.adapter); + data->hpdev.adapter = NULL; + } +} + +static ssize_t mlxreg_hotplug_attr_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct mlxreg_hotplug_priv_data *priv = dev_get_drvdata(dev); + struct mlxreg_core_hotplug_platform_data *pdata; + int index = to_sensor_dev_attr_2(attr)->index; + int nr = to_sensor_dev_attr_2(attr)->nr; + struct mlxreg_core_item *item; + struct mlxreg_core_data *data; + u32 regval; + int ret; + + pdata = dev_get_platdata(&priv->pdev->dev); + item = pdata->items + nr; + data = item->data + index; + + ret = regmap_read(priv->regmap, data->reg, ®val); + if (ret) + return ret; + + if (item->health) { + regval &= data->mask; + } else { + /* Bit = 0 : functional if item->inversed is true. */ + if (item->inversed) + regval = !(regval & data->mask); + else + regval = !!(regval & data->mask); + } + + return sprintf(buf, "%u\n", regval); +} + +#define PRIV_ATTR(i) priv->mlxreg_hotplug_attr[i] +#define PRIV_DEV_ATTR(i) priv->mlxreg_hotplug_dev_attr[i] + +static int mlxreg_hotplug_attr_init(struct mlxreg_hotplug_priv_data *priv) +{ + struct mlxreg_core_hotplug_platform_data *pdata; + struct mlxreg_core_item *item; + struct mlxreg_core_data *data; + int num_attrs = 0, id = 0, i, j; + + pdata = dev_get_platdata(&priv->pdev->dev); + item = pdata->items; + + /* Go over all kinds of items - psu, pwr, fan. */ + for (i = 0; i < pdata->counter; i++, item++) { + num_attrs += item->count; + data = item->data; + /* Go over all units within the item. */ + for (j = 0; j < item->count; j++, data++, id++) { + PRIV_ATTR(id) = &PRIV_DEV_ATTR(id).dev_attr.attr; + PRIV_ATTR(id)->name = devm_kasprintf(&priv->pdev->dev, + GFP_KERNEL, + data->label); + + if (!PRIV_ATTR(id)->name) { + dev_err(priv->dev, "Memory allocation failed for attr %d.\n", + id); + return -ENOMEM; + } + + PRIV_DEV_ATTR(id).dev_attr.attr.name = + PRIV_ATTR(id)->name; + PRIV_DEV_ATTR(id).dev_attr.attr.mode = 0444; + PRIV_DEV_ATTR(id).dev_attr.show = + mlxreg_hotplug_attr_show; + PRIV_DEV_ATTR(id).nr = i; + PRIV_DEV_ATTR(id).index = j; + sysfs_attr_init(&PRIV_DEV_ATTR(id).dev_attr.attr); + } + } + + priv->group.attrs = devm_kcalloc(&priv->pdev->dev, + num_attrs, + sizeof(struct attribute *), + GFP_KERNEL); + if (!priv->group.attrs) + return -ENOMEM; + + priv->group.attrs = priv->mlxreg_hotplug_attr; + priv->groups[0] = &priv->group; + priv->groups[1] = NULL; + + return 0; +} + +static void +mlxreg_hotplug_work_helper(struct mlxreg_hotplug_priv_data *priv, + struct mlxreg_core_item *item) +{ + struct mlxreg_core_data *data; + unsigned long asserted; + u32 regval, bit; + int ret; + + /* + * Validate if item related to received signal type is valid. + * It should never happen, excepted the situation when some + * piece of hardware is broken. In such situation just produce + * error message and return. Caller must continue to handle the + * signals from other devices if any. + */ + if (unlikely(!item)) { + dev_err(priv->dev, "False signal: at offset:mask 0x%02x:0x%02x.\n", + item->reg, item->mask); + + return; + } + + /* Mask event. */ + ret = regmap_write(priv->regmap, item->reg + MLXREG_HOTPLUG_MASK_OFF, + 0); + if (ret) + goto out; + + /* Read status. */ + ret = regmap_read(priv->regmap, item->reg, ®val); + if (ret) + goto out; + + /* Set asserted bits and save last status. */ + regval &= item->mask; + asserted = item->cache ^ regval; + item->cache = regval; + + for_each_set_bit(bit, &asserted, 8) { + data = item->data + bit; + if (regval & BIT(bit)) { + if (item->inversed) + mlxreg_hotplug_device_destroy(priv, data); + else + mlxreg_hotplug_device_create(priv, data); + } else { + if (item->inversed) + mlxreg_hotplug_device_create(priv, data); + else + mlxreg_hotplug_device_destroy(priv, data); + } + } + + /* Acknowledge event. */ + ret = regmap_write(priv->regmap, item->reg + MLXREG_HOTPLUG_EVENT_OFF, + 0); + if (ret) + goto out; + + /* Unmask event. */ + ret = regmap_write(priv->regmap, item->reg + MLXREG_HOTPLUG_MASK_OFF, + item->mask); + + out: + if (ret) + dev_err(priv->dev, "Failed to complete workqueue.\n"); +} + +static void +mlxreg_hotplug_health_work_helper(struct mlxreg_hotplug_priv_data *priv, + struct mlxreg_core_item *item) +{ + struct mlxreg_core_data *data = item->data; + u32 regval; + int i, ret = 0; + + for (i = 0; i < item->count; i++, data++) { + /* Mask event. */ + ret = regmap_write(priv->regmap, data->reg + + MLXREG_HOTPLUG_MASK_OFF, 0); + if (ret) + goto out; + + /* Read status. */ + ret = regmap_read(priv->regmap, data->reg, ®val); + if (ret) + goto out; + + regval &= data->mask; + + if (item->cache == regval) + goto ack_event; + + /* + * ASIC health indication is provided through two bits. Bits + * value 0x2 indicates that ASIC reached the good health, value + * 0x0 indicates ASIC the bad health or dormant state and value + * 0x3 indicates the booting state. During ASIC reset it should + * pass the following states: dormant -> booting -> good. + */ + if (regval == MLXREG_HOTPLUG_GOOD_HEALTH_MASK) { + if (!data->attached) { + /* + * ASIC is in steady state. Connect associated + * device, if configured. + */ + mlxreg_hotplug_device_create(priv, data); + data->attached = true; + } + } else { + if (data->attached) { + /* + * ASIC health is failed after ASIC has been + * in steady state. Disconnect associated + * device, if it has been connected. + */ + mlxreg_hotplug_device_destroy(priv, data); + data->attached = false; + data->health_cntr = 0; + } + } + item->cache = regval; +ack_event: + /* Acknowledge event. */ + ret = regmap_write(priv->regmap, data->reg + + MLXREG_HOTPLUG_EVENT_OFF, 0); + if (ret) + goto out; + + /* Unmask event. */ + ret = regmap_write(priv->regmap, data->reg + + MLXREG_HOTPLUG_MASK_OFF, data->mask); + if (ret) + goto out; + } + + out: + if (ret) + dev_err(priv->dev, "Failed to complete workqueue.\n"); +} + +/* + * mlxreg_hotplug_work_handler - performs traversing of device interrupt + * registers according to the below hierarchy schema: + * + * Aggregation registers (status/mask) + * PSU registers: *---* + * *-----------------* | | + * |status/event/mask|-----> | * | + * *-----------------* | | + * Power registers: | | + * *-----------------* | | + * |status/event/mask|-----> | * | + * *-----------------* | | + * FAN registers: | |--> CPU + * *-----------------* | | + * |status/event/mask|-----> | * | + * *-----------------* | | + * ASIC registers: | | + * *-----------------* | | + * |status/event/mask|-----> | * | + * *-----------------* | | + * *---* + * + * In case some system changed are detected: FAN in/out, PSU in/out, power + * cable attached/detached, ASIC health good/bad, relevant device is created + * or destroyed. + */ +static void mlxreg_hotplug_work_handler(struct work_struct *work) +{ + struct mlxreg_core_hotplug_platform_data *pdata; + struct mlxreg_hotplug_priv_data *priv; + struct mlxreg_core_item *item; + u32 regval, aggr_asserted; + unsigned long flags; + int i, ret; + + priv = container_of(work, struct mlxreg_hotplug_priv_data, + dwork_irq.work); + pdata = dev_get_platdata(&priv->pdev->dev); + item = pdata->items; + + /* Mask aggregation event. */ + ret = regmap_write(priv->regmap, pdata->cell + + MLXREG_HOTPLUG_AGGR_MASK_OFF, 0); + if (ret < 0) + goto out; + + /* Read aggregation status. */ + ret = regmap_read(priv->regmap, pdata->cell, ®val); + if (ret) + goto out; + + regval &= pdata->mask; + aggr_asserted = priv->aggr_cache ^ regval; + priv->aggr_cache = regval; + + /* + * Handler is invoked, but no assertion is detected at top aggregation + * status level. Set aggr_asserted to mask value to allow handler extra + * run over all relevant signals to recover any missed signal. + */ + if (priv->not_asserted == MLXREG_HOTPLUG_NOT_ASSERT) { + priv->not_asserted = 0; + aggr_asserted = pdata->mask; + } + if (!aggr_asserted) + goto unmask_event; + + /* Handle topology and health configuration changes. */ + for (i = 0; i < pdata->counter; i++, item++) { + if (aggr_asserted & item->aggr_mask) { + if (item->health) + mlxreg_hotplug_health_work_helper(priv, item); + else + mlxreg_hotplug_work_helper(priv, item); + } + } + + spin_lock_irqsave(&priv->lock, flags); + + /* + * It is possible, that some signals have been inserted, while + * interrupt has been masked by mlxreg_hotplug_work_handler. In this + * case such signals will be missed. In order to handle these signals + * delayed work is canceled and work task re-scheduled for immediate + * execution. It allows to handle missed signals, if any. In other case + * work handler just validates that no new signals have been received + * during masking. + */ + cancel_delayed_work(&priv->dwork_irq); + schedule_delayed_work(&priv->dwork_irq, 0); + + spin_unlock_irqrestore(&priv->lock, flags); + + return; + +unmask_event: + priv->not_asserted++; + /* Unmask aggregation event (no need acknowledge). */ + ret = regmap_write(priv->regmap, pdata->cell + + MLXREG_HOTPLUG_AGGR_MASK_OFF, pdata->mask); + + out: + if (ret) + dev_err(priv->dev, "Failed to complete workqueue.\n"); +} + +static int mlxreg_hotplug_set_irq(struct mlxreg_hotplug_priv_data *priv) +{ + struct mlxreg_core_hotplug_platform_data *pdata; + struct mlxreg_core_item *item; + int i, ret; + + pdata = dev_get_platdata(&priv->pdev->dev); + item = pdata->items; + + for (i = 0; i < pdata->counter; i++, item++) { + /* Clear group presense event. */ + ret = regmap_write(priv->regmap, item->reg + + MLXREG_HOTPLUG_EVENT_OFF, 0); + if (ret) + goto out; + + /* Set group initial status as mask and unmask group event. */ + if (item->inversed) { + item->cache = item->mask; + ret = regmap_write(priv->regmap, item->reg + + MLXREG_HOTPLUG_MASK_OFF, + item->mask); + if (ret) + goto out; + } + } + + /* Keep aggregation initial status as zero and unmask events. */ + ret = regmap_write(priv->regmap, pdata->cell + + MLXREG_HOTPLUG_AGGR_MASK_OFF, pdata->mask); + if (ret) + goto out; + + /* Keep low aggregation initial status as zero and unmask events. */ + if (pdata->cell_low) { + ret = regmap_write(priv->regmap, pdata->cell_low + + MLXREG_HOTPLUG_AGGR_MASK_OFF, + pdata->mask_low); + if (ret) + goto out; + } + + /* Invoke work handler for initializing hot plug devices setting. */ + mlxreg_hotplug_work_handler(&priv->dwork_irq.work); + + out: + if (ret) + dev_err(priv->dev, "Failed to set interrupts.\n"); + enable_irq(priv->irq); + return ret; +} + +static void mlxreg_hotplug_unset_irq(struct mlxreg_hotplug_priv_data *priv) +{ + struct mlxreg_core_hotplug_platform_data *pdata; + struct mlxreg_core_item *item; + struct mlxreg_core_data *data; + int count, i, j; + + pdata = dev_get_platdata(&priv->pdev->dev); + item = pdata->items; + disable_irq(priv->irq); + cancel_delayed_work_sync(&priv->dwork_irq); + + /* Mask low aggregation event, if defined. */ + if (pdata->cell_low) + regmap_write(priv->regmap, pdata->cell_low + + MLXREG_HOTPLUG_AGGR_MASK_OFF, 0); + + /* Mask aggregation event. */ + regmap_write(priv->regmap, pdata->cell + MLXREG_HOTPLUG_AGGR_MASK_OFF, + 0); + + /* Clear topology configurations. */ + for (i = 0; i < pdata->counter; i++, item++) { + data = item->data; + /* Mask group presense event. */ + regmap_write(priv->regmap, data->reg + MLXREG_HOTPLUG_MASK_OFF, + 0); + /* Clear group presense event. */ + regmap_write(priv->regmap, data->reg + + MLXREG_HOTPLUG_EVENT_OFF, 0); + + /* Remove all the attached devices in group. */ + count = item->count; + for (j = 0; j < count; j++, data++) + mlxreg_hotplug_device_destroy(priv, data); + } +} + +static irqreturn_t mlxreg_hotplug_irq_handler(int irq, void *dev) +{ + struct mlxreg_hotplug_priv_data *priv; + + priv = (struct mlxreg_hotplug_priv_data *)dev; + + /* Schedule work task for immediate execution.*/ + schedule_delayed_work(&priv->dwork_irq, 0); + + return IRQ_HANDLED; +} + +static int mlxreg_hotplug_probe(struct platform_device *pdev) +{ + struct mlxreg_core_hotplug_platform_data *pdata; + struct mlxreg_hotplug_priv_data *priv; + struct i2c_adapter *deferred_adap; + int err; + + pdata = dev_get_platdata(&pdev->dev); + if (!pdata) { + dev_err(&pdev->dev, "Failed to get platform data.\n"); + return -EINVAL; + } + + /* Defer probing if the necessary adapter is not configured yet. */ + deferred_adap = i2c_get_adapter(pdata->deferred_nr); + if (!deferred_adap) + return -EPROBE_DEFER; + i2c_put_adapter(deferred_adap); + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + if (pdata->irq) { + priv->irq = pdata->irq; + } else { + priv->irq = platform_get_irq(pdev, 0); + if (priv->irq < 0) { + dev_err(&pdev->dev, "Failed to get platform irq: %d\n", + priv->irq); + return priv->irq; + } + } + + priv->regmap = pdata->regmap; + priv->dev = pdev->dev.parent; + priv->pdev = pdev; + + err = devm_request_irq(&pdev->dev, priv->irq, + mlxreg_hotplug_irq_handler, IRQF_TRIGGER_FALLING + | IRQF_SHARED, "mlxreg-hotplug", priv); + if (err) { + dev_err(&pdev->dev, "Failed to request irq: %d\n", err); + return err; + } + + disable_irq(priv->irq); + spin_lock_init(&priv->lock); + INIT_DELAYED_WORK(&priv->dwork_irq, mlxreg_hotplug_work_handler); + dev_set_drvdata(&pdev->dev, priv); + + err = mlxreg_hotplug_attr_init(priv); + if (err) { + dev_err(&pdev->dev, "Failed to allocate attributes: %d\n", + err); + return err; + } + + priv->hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, + "mlxreg_hotplug", 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); + } + + /* Perform initial interrupts setup. */ + mlxreg_hotplug_set_irq(priv); + priv->after_probe = true; + + return 0; +} + +static int mlxreg_hotplug_remove(struct platform_device *pdev) +{ + struct mlxreg_hotplug_priv_data *priv = dev_get_drvdata(&pdev->dev); + + /* Clean interrupts setup. */ + mlxreg_hotplug_unset_irq(priv); + devm_free_irq(&pdev->dev, priv->irq, priv); + + return 0; +} + +static struct platform_driver mlxreg_hotplug_driver = { + .driver = { + .name = "mlxreg-hotplug", + }, + .probe = mlxreg_hotplug_probe, + .remove = mlxreg_hotplug_remove, +}; + +module_platform_driver(mlxreg_hotplug_driver); + +MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>"); +MODULE_DESCRIPTION("Mellanox regmap hotplug platform driver"); +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_ALIAS("platform:mlxreg-hotplug"); |