В настоящее время я выполняю рефакторинг драйвера для AMD Sensor Fusion Hub. Оригинальный драйвер можно найти здесь . При отправке команд на устройство чип обрабатывает запрос некоторое время. Я использовал хак, используя msleep, чтобы дождаться ответа устройства. Однако я хотел бы аккуратно реализовать обработку IRQ. В качестве шаблона я рассмотрел реализацию drivers/i2c/busses/i2c-amd-mp2-pci.c и придумал следующую обработку прерываний заглушки.
// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
* AMD Sensor Fusion Hub (SFH) PCIe driver
*
* Authors: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
* Nehal Bakulchandra Shah <Nehal-bakulchandra.Shah@amd.com>
* Richard Neumann <mail@richard-neumann.de>
*/
#include <linux/bitops.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/io-64-nonatomic-lo-hi.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/pm_runtime.h>
#include <linux/types.h>
#include "amd-sfh-pci.h"
/**
* amd_sfh_get_sensor_mask - Returns the sensors mask.
* @pci_dev: The Sensor Fusion Hub PCI device
*
* Returns an unsigned integer representing the bitmask to match
* the sensors connected to the Sensor Fusion Hub.
*/
int amd_sfh_get_sensor_mask(struct pci_dev *pci_dev)
{
int sensor_mask;
struct amd_sfh_dev *sfh_dev = pci_get_drvdata(pci_dev);
sensor_mask = readl(sfh_dev->mmio + AMD_SFH_SENSOR_MASK);
/* Correct bit shift in firmware register */
sensor_mask = sensor_mask >> 4;
if (!sensor_mask)
dev_err(&pci_dev->dev, "no sensors marked active on device\n");
return sensor_mask;
}
EXPORT_SYMBOL_GPL(amd_sfh_get_sensor_mask);
/**
* amd_sfh_start_sensor- Starts the respective sensor.
* @pci_dev: The Sensor Fusion Hub PCI device
* @sensor_idx: The sensor's index
* @dma_handle: The DMA handle
*/
void amd_sfh_start_sensor(struct pci_dev *pci_dev, enum sensor_idx sensor_idx,
dma_addr_t dma_handle)
{
struct amd_sfh_dev *sfh_dev = pci_get_drvdata(pci_dev);
union amd_sfh_cmd command;
union amd_sfh_parm parameter;
command.ul = 0;
command.s.cmd_id = enable_sensor;
command.s.period = PERIOD;
command.s.sensor_id = sensor_idx;
parameter.ul = 0;
parameter.s.buffer_layout = 1;
parameter.s.buffer_length = 16;
writeq(dma_handle, sfh_dev->mmio + AMD_SFH_ADDR);
writel(parameter.ul, sfh_dev->mmio + AMD_SFH_PARM);
writel(command.ul, sfh_dev->mmio + AMD_SFH_CMD);
}
EXPORT_SYMBOL_GPL(amd_sfh_start_sensor);
/**
* amd_sfh_stop_sensor- Stops the respective sensor.
* @pci_dev: The Sensor Fusion Hub PCI device
* @sensor_idx: The sensor's index
*/
void amd_sfh_stop_sensor(struct pci_dev *pci_dev, enum sensor_idx sensor_idx)
{
struct amd_sfh_dev *sfh_dev = pci_get_drvdata(pci_dev);
union amd_sfh_cmd command;
command.ul = 0;
command.s.cmd_id = disable_sensor;
command.s.period = 0;
command.s.sensor_id = sensor_idx;
writeq(0x0, sfh_dev->mmio + AMD_SFH_ADDR);
writel(command.ul, sfh_dev->mmio + AMD_SFH_CMD);
}
EXPORT_SYMBOL_GPL(amd_sfh_stop_sensor);
/**
* amd_sfh_stop_all_sensors- Stops all sensors on the SFH.
* @pci_dev: The Sensor Fusion Hub PCI device
*/
static void amd_sfh_stop_all_sensors(struct pci_dev *pci_dev)
{
struct amd_sfh_dev *sfh_dev = pci_get_drvdata(pci_dev);
union amd_sfh_cmd command;
command.ul = 0;
command.s.cmd_id = stop_all_sensors;
command.s.period = 0;
command.s.sensor_id = 0;
writel(command.ul, sfh_dev->mmio + AMD_SFH_CMD);
}
/**
* amd_sfh_irq_isr - IRQ handler
* @irq: The IRQ number received
* @dev: The underlying device
*/
static irqreturn_t amd_sfh_irq_isr(int irq, void *dev)
{
struct amd_sfh_dev *sfh_dev = dev;
dev_info(&sfh_dev->pci_dev->dev, "got IRQ: %d\n", irq);
return IRQ_NONE;
}
/**
* amd_sfh_pci_init - Initializes the PCI device
* @sfh_dev: The device data
* @pci_dev: The PCI device
*/
static int amd_sfh_pci_init(struct amd_sfh_dev *sfh_dev,
struct pci_dev *pci_dev)
{
int rc;
pci_set_drvdata(pci_dev, sfh_dev);
rc = pcim_enable_device(pci_dev);
if (rc)
goto err_pci_enable;
rc = pcim_iomap_regions(pci_dev, BIT(2), pci_name(pci_dev));
if (rc)
goto err_pci_enable;
sfh_dev->pci_dev = pci_dev;
sfh_dev->mmio = pcim_iomap_table(pci_dev)[2];
pci_set_master(pci_dev);
rc = pci_set_dma_mask(pci_dev, DMA_BIT_MASK(64));
if (rc) {
rc = pci_set_dma_mask(pci_dev, DMA_BIT_MASK(32));
if (rc)
goto err_dma_mask;
}
/* Set up intx irq */
writel(0, sfh_dev->mmio + AMD_P2C_MSG_INTEN);
pci_intx(pci_dev, 1);
dev_info(&pci_dev->dev, "available interrupt: %d\n", pci_dev->irq);
rc = devm_request_irq(&pci_dev->dev, pci_dev->irq, amd_sfh_irq_isr,
0, dev_name(&pci_dev->dev), sfh_dev);
if (rc)
dev_err(&pci_dev->dev, "Failure requesting irq %i: %d\n",
pci_dev->irq, rc);
return rc;
err_dma_mask:
pci_clear_master(pci_dev);
err_pci_enable:
return rc;
}
static int amd_sfh_pci_probe(struct pci_dev *pci_dev,
const struct pci_device_id *id)
{
int rc;
struct amd_sfh_dev *sfh_dev;
sfh_dev = devm_kzalloc(&pci_dev->dev, sizeof(*sfh_dev), GFP_KERNEL);
if (!sfh_dev)
return -ENOMEM;
rc = amd_sfh_pci_init(sfh_dev, pci_dev);
if (rc)
return rc;
pm_runtime_set_autosuspend_delay(&pci_dev->dev, 1000);
pm_runtime_use_autosuspend(&pci_dev->dev);
pm_runtime_put_autosuspend(&pci_dev->dev);
pm_runtime_allow(&pci_dev->dev);
dev_info(&pci_dev->dev, "SFH device registered.\n");
return 0;
}
static void amd_sfh_pci_remove(struct pci_dev *pci_dev)
{
struct amd_sfh_dev *sfh_dev = pci_get_drvdata(pci_dev);
amd_sfh_stop_all_sensors(sfh_dev->pci_dev);
pm_runtime_forbid(&pci_dev->dev);
pm_runtime_get_noresume(&pci_dev->dev);
pci_intx(pci_dev, 0);
pci_clear_master(pci_dev);
}
static const struct pci_device_id amd_sfh_pci_tbl[] = {
{PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_SFH)},
{0}
};
MODULE_DEVICE_TABLE(pci, amd_sfh_pci_tbl);
static struct pci_driver amd_sfh_pci_driver = {
.name = "amd-sfh-pci",
.id_table = amd_sfh_pci_tbl,
.probe = amd_sfh_pci_probe,
.remove = amd_sfh_pci_remove,
};
module_pci_driver(amd_sfh_pci_driver);
/**
* amd_sfh_find_device - Returns the first best AMD SFH device.
*/
struct amd_sfh_dev *amd_sfh_find_device(void)
{
struct device *dev;
struct pci_dev *pci_dev;
dev = driver_find_next_device(&amd_sfh_pci_driver.driver, NULL);
if (!dev)
return NULL;
pci_dev = to_pci_dev(dev);
return pci_get_drvdata(pci_dev);
}
EXPORT_SYMBOL_GPL(amd_sfh_find_device);
MODULE_DESCRIPTION("AMD(R) Sensor Fusion Hub PCI driver");
MODULE_AUTHOR("Shyam Sundar S K <Shyam-sundar.S-k@amd.com>");
MODULE_AUTHOR("Nehal Bakulchandra Shah <Nehal-bakulchandra.Shah@amd.com>");
MODULE_AUTHOR("Richard Neumann <mail@richard-neumann.de>");
MODULE_LICENSE("Dual BSD/GPL");
Однако dev_info из amd_sfh_irq_isr никогда не регистрируется, поэтому я подозреваю, что IRQ никогда не срабатывает при записи в регистры устройства. В чем может быть причина этого и что я могу сделать, чтобы правильно реализовать обработку IRQ?
PS dmesg вывод:
[ 2272.642762] amd-sfh-pci 0000:04:00.7: available interrupt: 56
[ 2272.642840] amd-sfh-pci 0000:04:00.7: SFH device registered.
Обновление Устройство поддерживает MSI:
04:00.7 Non-VGA unclassified device [0000]: Advanced Micro Devices, Inc. [AMD] Raven/Raven2/Renoir Sensor Fusion Hub [1022:15e4]
Subsystem: Hewlett-Packard Company Raven/Raven2/Renoir Sensor Fusion Hub [103c:8496]
Flags: bus master, fast devsel, latency 0, IRQ 56
Memory at fc800000 (32-bit, non-prefetchable) [size=1M]
Memory at fcc8c000 (32-bit, non-prefetchable) [size=8K]
Capabilities: [48] Vendor Specific Information: Len=08 <?>
Capabilities: [50] Power Management version 3
Capabilities: [64] Express Endpoint, MSI 00
Capabilities: [a0] MSI: Enable- Count=1/2 Maskable- 64bit+
Capabilities: [c0] MSI-X: Enable- Count=2 Masked-
Capabilities: [100] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
Kernel modules: amd_sfh_pci
Но прерывания по-прежнему не принимаются и не обрабатываются:
static void amd_sfh_debug(struct pci_dev *pci_dev)
{
bool msi;
msi = pci_dev_msi_enabled(pci_dev);
pci_info(pci_dev, "MSI: %s\n", msi ? "true" : "false");
pci_info(pci_dev, "No MSI: %s\n", pci_dev->no_msi ? "true" : "false");
}
/**
* amd_sfh_handle_irq - Handles IRQs.
* @irq: The interrupt request to be handled
* @dev: The driver data
*
* Returns an appropriate IRQ return type.
*/
static irqreturn_t amd_sfh_handle_irq(int irq, void *dev)
{
struct amd_sfh_dev *privdata = dev;
pci_info(privdata->pci_dev, "got IRQ: %d\n", irq);
return IRQ_NONE;
}
static int amd_sfh_setup_irq(struct amd_sfh_dev *privdata)
{
int rc, vecs, irq;
struct pci_dev *pci_dev = privdata->pci_dev;
vecs = pci_alloc_irq_vectors(pci_dev, 1, 3, PCI_IRQ_ALL_TYPES);
if (vecs < 0)
return vecs;
pci_info(pci_dev, "allocated %d IRQ vectors\n", vecs);
for (irq = 0; irq < vecs; irq++) {
pci_info(pci_dev, "requesting IRQ: %d\n", irq);
rc = devm_request_irq(&pci_dev->dev,
pci_irq_vector(pci_dev, irq),
amd_sfh_handle_irq, 0, "sfh-irq",
privdata);
if (rc) {
pci_err(pci_dev, "failed to get IRQ\n");
goto free_irq_vectors;
}
}
return 0;
free_irq_vectors:
pci_free_irq_vectors(pci_dev);
return rc;
}
static int amd_sfh_pci_init(struct amd_sfh_dev *privdata,
struct pci_dev *pci_dev)
{
int rc;
pci_set_drvdata(pci_dev, privdata);
rc = pcim_enable_device(pci_dev);
if (rc)
return rc;
rc = pcim_iomap_regions(pci_dev, BIT(2), pci_name(pci_dev));
if (rc)
return rc;
privdata->pci_dev = pci_dev;
privdata->mmio = pcim_iomap_table(pci_dev)[2];
pci_set_master(pci_dev);
rc = pci_set_dma_mask(pci_dev, DMA_BIT_MASK(64));
if (rc) {
rc = pci_set_dma_mask(pci_dev, DMA_BIT_MASK(32));
if (rc)
goto clear_master;
}
/* Setup IRQ */
amd_sfh_debug(pci_dev);
rc = amd_sfh_setup_irq(privdata);
if (rc)
goto clear_master;
amd_sfh_debug(pci_dev);
/* End of IRQ setup */
pci_info(pci_dev, "AMD Sensor Fusion Hub device initialized\n");
return 0;
clear_master:
pci_clear_master(pci_dev);
return rc;
}
dmesg:
[ 6.954524] amd-sfh-pci 0000:04:00.7: enabling device (0000 -> 0002)
[ 6.954641] amd-sfh-pci 0000:04:00.7: MSI: false
[ 6.954642] amd-sfh-pci 0000:04:00.7: No MSI: false
[ 6.954791] amd-sfh-pci 0000:04:00.7: allocated 2 IRQ vectors
[ 6.954792] amd-sfh-pci 0000:04:00.7: requesting IRQ: 0
[ 6.954825] amd-sfh-pci 0000:04:00.7: requesting IRQ: 1
[ 6.954860] amd-sfh-pci 0000:04:00.7: MSI: true
[ 6.954861] amd-sfh-pci 0000:04:00.7: No MSI: false
[ 6.954861] amd-sfh-pci 0000:04:00.7: AMD Sensor Fusion Hub device initialized
[ 6.969691] amd-sfh-pci 0000:04:00.7: [Firmware Bug]: No sensors marked active!
[ 6.971265] amd-sfh-pci 0000:04:00.7: sensor mask: 0x000001
[ 7.548189] hid-generic 0018:03FE:0001.0001: hidraw0: I2C HID v0.01 Device [amd-sfh-accel] on
оригинальная документация AMD упоминает прерывания, но не слишком точно указывает c о том, как они генерируются.