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linux/linux-5.4.31/drivers/platform/mellanox/mlxreg-hotplug.c

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/*
* 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, &regval);
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, &regval);
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, &regval);
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, &regval);
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;
struct mlxreg_core_data *data;
u32 regval;
int i, j, 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;
/*
* Verify if hardware configuration requires to disable
* interrupt capability for some of components.
*/
data = item->data;
for (j = 0; j < item->count; j++, data++) {
/* Verify if the attribute has capability register. */
if (data->capability) {
/* Read capability register. */
ret = regmap_read(priv->regmap,
data->capability, &regval);
if (ret)
goto out;
if (!(regval & data->bit))
item->mask &= ~BIT(j);
}
}
/* 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)
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");
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