linux/drivers/platform/x86/mlxcpld-hotplug.c
Vadim Pasternak 304887041d platform/x86: Introduce support for Mellanox hotplug driver
Enable system support for the Mellanox Technologies hotplug platform
driver, which provides support for the next Mellanox basic systems:
"msx6710", "msx6720", "msb7700", "msn2700", "msx1410", "msn2410",
"msb7800", "msn2740", "msn2100" and also various number of derivative
systems from the above basic types.
This driver handles hot-plug events for the power suppliers, power
cables and fans for the above systems.

The Kconfig currently controlling compilation of this code is:
driver/platform/x86:config MLX_CPLD_PLATFORM
                       tristate "Mellanox platform hotplug driver support"

Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
2016-10-23 07:52:57 -07:00

516 lines
16 KiB
C

/*
* drivers/platform/x86/mlxcpld-hotplug.c
* Copyright (c) 2016 Mellanox Technologies. All rights reserved.
* Copyright (c) 2016 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/io.h>
#include <linux/module.h>
#include <linux/platform_data/mlxcpld-hotplug.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
/* Offset of event and mask registers from status register */
#define MLXCPLD_HOTPLUG_EVENT_OFF 1
#define MLXCPLD_HOTPLUG_MASK_OFF 2
#define MLXCPLD_HOTPLUG_AGGR_MASK_OFF 1
#define MLXCPLD_HOTPLUG_ATTRS_NUM 8
/**
* enum mlxcpld_hotplug_attr_type - sysfs attributes for hotplug events:
* @MLXCPLD_HOTPLUG_ATTR_TYPE_PSU: power supply unit attribute;
* @MLXCPLD_HOTPLUG_ATTR_TYPE_PWR: power cable attribute;
* @MLXCPLD_HOTPLUG_ATTR_TYPE_FAN: FAN drawer attribute;
*/
enum mlxcpld_hotplug_attr_type {
MLXCPLD_HOTPLUG_ATTR_TYPE_PSU,
MLXCPLD_HOTPLUG_ATTR_TYPE_PWR,
MLXCPLD_HOTPLUG_ATTR_TYPE_FAN,
};
/**
* struct mlxcpld_hotplug_priv_data - platform private data:
* @irq: platform interrupt number;
* @pdev: platform device;
* @plat: platform data;
* @hwmon: hwmon device;
* @mlxcpld_hotplug_attr: sysfs attributes array;
* @mlxcpld_hotplug_dev_attr: sysfs sensor device attribute array;
* @group: sysfs attribute group;
* @groups: list of sysfs attribute group for hwmon registration;
* @dwork: delayed work template;
* @lock: spin lock;
* @aggr_cache: last value of aggregation register status;
* @psu_cache: last value of PSU register status;
* @pwr_cache: last value of power register status;
* @fan_cache: last value of FAN register status;
*/
struct mlxcpld_hotplug_priv_data {
int irq;
struct platform_device *pdev;
struct mlxcpld_hotplug_platform_data *plat;
struct device *hwmon;
struct attribute *mlxcpld_hotplug_attr[MLXCPLD_HOTPLUG_ATTRS_NUM + 1];
struct sensor_device_attribute_2
mlxcpld_hotplug_dev_attr[MLXCPLD_HOTPLUG_ATTRS_NUM];
struct attribute_group group;
const struct attribute_group *groups[2];
struct delayed_work dwork;
spinlock_t lock;
u8 aggr_cache;
u8 psu_cache;
u8 pwr_cache;
u8 fan_cache;
};
static ssize_t mlxcpld_hotplug_attr_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct platform_device *pdev = to_platform_device(dev);
struct mlxcpld_hotplug_priv_data *priv = platform_get_drvdata(pdev);
int index = to_sensor_dev_attr_2(attr)->index;
int nr = to_sensor_dev_attr_2(attr)->nr;
u8 reg_val = 0;
switch (nr) {
case MLXCPLD_HOTPLUG_ATTR_TYPE_PSU:
/* Bit = 0 : PSU is present. */
reg_val = !!!(inb(priv->plat->psu_reg_offset) & BIT(index));
break;
case MLXCPLD_HOTPLUG_ATTR_TYPE_PWR:
/* Bit = 1 : power cable is attached. */
reg_val = !!(inb(priv->plat->pwr_reg_offset) & BIT(index %
priv->plat->pwr_count));
break;
case MLXCPLD_HOTPLUG_ATTR_TYPE_FAN:
/* Bit = 0 : FAN is present. */
reg_val = !!!(inb(priv->plat->fan_reg_offset) & BIT(index %
priv->plat->fan_count));
break;
}
return sprintf(buf, "%u\n", reg_val);
}
#define PRIV_ATTR(i) priv->mlxcpld_hotplug_attr[i]
#define PRIV_DEV_ATTR(i) priv->mlxcpld_hotplug_dev_attr[i]
static int mlxcpld_hotplug_attr_init(struct mlxcpld_hotplug_priv_data *priv)
{
int num_attrs = priv->plat->psu_count + priv->plat->pwr_count +
priv->plat->fan_count;
int i;
priv->group.attrs = devm_kzalloc(&priv->pdev->dev, num_attrs *
sizeof(struct attribute *),
GFP_KERNEL);
if (!priv->group.attrs)
return -ENOMEM;
for (i = 0; i < num_attrs; i++) {
PRIV_ATTR(i) = &PRIV_DEV_ATTR(i).dev_attr.attr;
if (i < priv->plat->psu_count) {
PRIV_ATTR(i)->name = devm_kasprintf(&priv->pdev->dev,
GFP_KERNEL, "psu%u", i + 1);
PRIV_DEV_ATTR(i).nr = MLXCPLD_HOTPLUG_ATTR_TYPE_PSU;
} else if (i < priv->plat->psu_count + priv->plat->pwr_count) {
PRIV_ATTR(i)->name = devm_kasprintf(&priv->pdev->dev,
GFP_KERNEL, "pwr%u", i %
priv->plat->pwr_count + 1);
PRIV_DEV_ATTR(i).nr = MLXCPLD_HOTPLUG_ATTR_TYPE_PWR;
} else {
PRIV_ATTR(i)->name = devm_kasprintf(&priv->pdev->dev,
GFP_KERNEL, "fan%u", i %
priv->plat->fan_count + 1);
PRIV_DEV_ATTR(i).nr = MLXCPLD_HOTPLUG_ATTR_TYPE_FAN;
}
if (!PRIV_ATTR(i)->name) {
dev_err(&priv->pdev->dev, "Memory allocation failed for sysfs attribute %d.\n",
i + 1);
return -ENOMEM;
}
PRIV_DEV_ATTR(i).dev_attr.attr.name = PRIV_ATTR(i)->name;
PRIV_DEV_ATTR(i).dev_attr.attr.mode = S_IRUGO;
PRIV_DEV_ATTR(i).dev_attr.show = mlxcpld_hotplug_attr_show;
PRIV_DEV_ATTR(i).index = i;
sysfs_attr_init(&PRIV_DEV_ATTR(i).dev_attr.attr);
}
priv->group.attrs = priv->mlxcpld_hotplug_attr;
priv->groups[0] = &priv->group;
priv->groups[1] = NULL;
return 0;
}
static int mlxcpld_hotplug_device_create(struct device *dev,
struct mlxcpld_hotplug_device *item)
{
item->adapter = i2c_get_adapter(item->bus);
if (!item->adapter) {
dev_err(dev, "Failed to get adapter for bus %d\n",
item->bus);
return -EFAULT;
}
item->client = i2c_new_device(item->adapter, &item->brdinfo);
if (!item->client) {
dev_err(dev, "Failed to create client %s at bus %d at addr 0x%02x\n",
item->brdinfo.type, item->bus, item->brdinfo.addr);
i2c_put_adapter(item->adapter);
item->adapter = NULL;
return -EFAULT;
}
return 0;
}
static void mlxcpld_hotplug_device_destroy(struct mlxcpld_hotplug_device *item)
{
if (item->client) {
i2c_unregister_device(item->client);
item->client = NULL;
}
if (item->adapter) {
i2c_put_adapter(item->adapter);
item->adapter = NULL;
}
}
static inline void
mlxcpld_hotplug_work_helper(struct device *dev,
struct mlxcpld_hotplug_device *item, u8 is_inverse,
u16 offset, u8 mask, u8 *cache)
{
u8 val, asserted;
int bit;
/* Mask event. */
outb(0, offset + MLXCPLD_HOTPLUG_MASK_OFF);
/* Read status. */
val = inb(offset) & mask;
asserted = *cache ^ val;
*cache = val;
/*
* 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(dev, "False signal is received: register at offset 0x%02x, mask 0x%02x.\n",
offset, mask);
return;
}
for_each_set_bit(bit, (unsigned long *)&asserted, 8) {
if (val & BIT(bit)) {
if (is_inverse)
mlxcpld_hotplug_device_destroy(item + bit);
else
mlxcpld_hotplug_device_create(dev, item + bit);
} else {
if (is_inverse)
mlxcpld_hotplug_device_create(dev, item + bit);
else
mlxcpld_hotplug_device_destroy(item + bit);
}
}
/* Acknowledge event. */
outb(0, offset + MLXCPLD_HOTPLUG_EVENT_OFF);
/* Unmask event. */
outb(mask, offset + MLXCPLD_HOTPLUG_MASK_OFF);
}
/*
* mlxcpld_hotplug_work_handler - performs traversing of CPLD interrupt
* registers according to the below hierarchy schema:
*
* Aggregation registers (status/mask)
* PSU registers: *---*
* *-----------------* | |
* |status/event/mask|----->| * |
* *-----------------* | |
* Power registers: | |
* *-----------------* | |
* |status/event/mask|----->| * |---> CPU
* *-----------------* | |
* FAN registers:
* *-----------------* | |
* |status/event/mask|----->| * |
* *-----------------* | |
* *---*
* In case some system changed are detected: FAN in/out, PSU in/out, power
* cable attached/detached, relevant device is created or destroyed.
*/
static void mlxcpld_hotplug_work_handler(struct work_struct *work)
{
struct mlxcpld_hotplug_priv_data *priv = container_of(work,
struct mlxcpld_hotplug_priv_data, dwork.work);
u8 val, aggr_asserted;
unsigned long flags;
/* Mask aggregation event. */
outb(0, priv->plat->top_aggr_offset + MLXCPLD_HOTPLUG_AGGR_MASK_OFF);
/* Read aggregation status. */
val = inb(priv->plat->top_aggr_offset) & priv->plat->top_aggr_mask;
aggr_asserted = priv->aggr_cache ^ val;
priv->aggr_cache = val;
/* Handle PSU configuration changes. */
if (aggr_asserted & priv->plat->top_aggr_psu_mask)
mlxcpld_hotplug_work_helper(&priv->pdev->dev, priv->plat->psu,
1, priv->plat->psu_reg_offset,
priv->plat->psu_mask,
&priv->psu_cache);
/* Handle power cable configuration changes. */
if (aggr_asserted & priv->plat->top_aggr_pwr_mask)
mlxcpld_hotplug_work_helper(&priv->pdev->dev, priv->plat->pwr,
0, priv->plat->pwr_reg_offset,
priv->plat->pwr_mask,
&priv->pwr_cache);
/* Handle FAN configuration changes. */
if (aggr_asserted & priv->plat->top_aggr_fan_mask)
mlxcpld_hotplug_work_helper(&priv->pdev->dev, priv->plat->fan,
1, priv->plat->fan_reg_offset,
priv->plat->fan_mask,
&priv->fan_cache);
if (aggr_asserted) {
spin_lock_irqsave(&priv->lock, flags);
/*
* It is possible, that some signals have been inserted, while
* interrupt has been masked by mlxcpld_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);
schedule_delayed_work(&priv->dwork, 0);
spin_unlock_irqrestore(&priv->lock, flags);
return;
}
/* Unmask aggregation event (no need acknowledge). */
outb(priv->plat->top_aggr_mask, priv->plat->top_aggr_offset +
MLXCPLD_HOTPLUG_AGGR_MASK_OFF);
}
static void mlxcpld_hotplug_set_irq(struct mlxcpld_hotplug_priv_data *priv)
{
/* Clear psu presense event. */
outb(0, priv->plat->psu_reg_offset + MLXCPLD_HOTPLUG_EVENT_OFF);
/* Set psu initial status as mask and unmask psu event. */
priv->psu_cache = priv->plat->psu_mask;
outb(priv->plat->psu_mask, priv->plat->psu_reg_offset +
MLXCPLD_HOTPLUG_MASK_OFF);
/* Clear power cable event. */
outb(0, priv->plat->pwr_reg_offset + MLXCPLD_HOTPLUG_EVENT_OFF);
/* Keep power initial status as zero and unmask power event. */
outb(priv->plat->pwr_mask, priv->plat->pwr_reg_offset +
MLXCPLD_HOTPLUG_MASK_OFF);
/* Clear fan presense event. */
outb(0, priv->plat->fan_reg_offset + MLXCPLD_HOTPLUG_EVENT_OFF);
/* Set fan initial status as mask and unmask fan event. */
priv->fan_cache = priv->plat->fan_mask;
outb(priv->plat->fan_mask, priv->plat->fan_reg_offset +
MLXCPLD_HOTPLUG_MASK_OFF);
/* Keep aggregation initial status as zero and unmask events. */
outb(priv->plat->top_aggr_mask, priv->plat->top_aggr_offset +
MLXCPLD_HOTPLUG_AGGR_MASK_OFF);
/* Invoke work handler for initializing hot plug devices setting. */
mlxcpld_hotplug_work_handler(&priv->dwork.work);
enable_irq(priv->irq);
}
static void mlxcpld_hotplug_unset_irq(struct mlxcpld_hotplug_priv_data *priv)
{
int i;
disable_irq(priv->irq);
cancel_delayed_work_sync(&priv->dwork);
/* Mask aggregation event. */
outb(0, priv->plat->top_aggr_offset + MLXCPLD_HOTPLUG_AGGR_MASK_OFF);
/* Mask psu presense event. */
outb(0, priv->plat->psu_reg_offset + MLXCPLD_HOTPLUG_MASK_OFF);
/* Clear psu presense event. */
outb(0, priv->plat->psu_reg_offset + MLXCPLD_HOTPLUG_EVENT_OFF);
/* Mask power cable event. */
outb(0, priv->plat->pwr_reg_offset + MLXCPLD_HOTPLUG_MASK_OFF);
/* Clear power cable event. */
outb(0, priv->plat->pwr_reg_offset + MLXCPLD_HOTPLUG_EVENT_OFF);
/* Mask fan presense event. */
outb(0, priv->plat->fan_reg_offset + MLXCPLD_HOTPLUG_MASK_OFF);
/* Clear fan presense event. */
outb(0, priv->plat->fan_reg_offset + MLXCPLD_HOTPLUG_EVENT_OFF);
/* Remove all the attached devices. */
for (i = 0; i < priv->plat->psu_count; i++)
mlxcpld_hotplug_device_destroy(priv->plat->psu + i);
for (i = 0; i < priv->plat->pwr_count; i++)
mlxcpld_hotplug_device_destroy(priv->plat->pwr + i);
for (i = 0; i < priv->plat->fan_count; i++)
mlxcpld_hotplug_device_destroy(priv->plat->fan + i);
}
static irqreturn_t mlxcpld_hotplug_irq_handler(int irq, void *dev)
{
struct mlxcpld_hotplug_priv_data *priv =
(struct mlxcpld_hotplug_priv_data *)dev;
/* Schedule work task for immediate execution.*/
schedule_delayed_work(&priv->dwork, 0);
return IRQ_HANDLED;
}
static int mlxcpld_hotplug_probe(struct platform_device *pdev)
{
struct mlxcpld_hotplug_platform_data *pdata;
struct mlxcpld_hotplug_priv_data *priv;
int err;
pdata = dev_get_platdata(&pdev->dev);
if (!pdata) {
dev_err(&pdev->dev, "Failed to get platform data.\n");
return -EINVAL;
}
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->pdev = pdev;
priv->plat = pdata;
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;
}
err = devm_request_irq(&pdev->dev, priv->irq,
mlxcpld_hotplug_irq_handler, 0, pdev->name,
priv);
if (err) {
dev_err(&pdev->dev, "Failed to request irq: %d\n", err);
return err;
}
disable_irq(priv->irq);
INIT_DELAYED_WORK(&priv->dwork, mlxcpld_hotplug_work_handler);
spin_lock_init(&priv->lock);
err = mlxcpld_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,
"mlxcpld_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);
}
platform_set_drvdata(pdev, priv);
/* Perform initial interrupts setup. */
mlxcpld_hotplug_set_irq(priv);
return 0;
}
static int mlxcpld_hotplug_remove(struct platform_device *pdev)
{
struct mlxcpld_hotplug_priv_data *priv = platform_get_drvdata(pdev);
/* Clean interrupts setup. */
mlxcpld_hotplug_unset_irq(priv);
return 0;
}
static struct platform_driver mlxcpld_hotplug_driver = {
.driver = {
.name = "mlxcpld-hotplug",
},
.probe = mlxcpld_hotplug_probe,
.remove = mlxcpld_hotplug_remove,
};
module_platform_driver(mlxcpld_hotplug_driver);
MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
MODULE_DESCRIPTION("Mellanox CPLD hotplug platform driver");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_ALIAS("platform:mlxcpld-hotplug");