2020-07-15 15:14:54

by Marius Zachmann

[permalink] [raw]
Subject: [PATCH v2] hwmon: corsair-cpro: Change to HID driver

This changes corsair-cpro to a hid driver using hid reports.

Signed-off-by: Marius Zachmann <[email protected]>

---
Changes from v1
- add comment at the beginning about using hid and hidraw
- use hwmon_device_register_with_info and hwmon_device_unregister
- use a define for timeout

---
drivers/hid/hid-quirks.c | 2 -
drivers/hwmon/Kconfig | 2 +-
drivers/hwmon/corsair-cpro.c | 124 ++++++++++++++++++++++++++---------
3 files changed, 95 insertions(+), 35 deletions(-)

diff --git a/drivers/hid/hid-quirks.c b/drivers/hid/hid-quirks.c
index 7b7bc7737c53..ca8b5c261c7c 100644
--- a/drivers/hid/hid-quirks.c
+++ b/drivers/hid/hid-quirks.c
@@ -699,8 +699,6 @@ static const struct hid_device_id hid_ignore_list[] = {
{ HID_USB_DEVICE(USB_VENDOR_ID_AXENTIA, USB_DEVICE_ID_AXENTIA_FM_RADIO) },
{ HID_USB_DEVICE(USB_VENDOR_ID_BERKSHIRE, USB_DEVICE_ID_BERKSHIRE_PCWD) },
{ HID_USB_DEVICE(USB_VENDOR_ID_CIDC, 0x0103) },
- { HID_USB_DEVICE(USB_VENDOR_ID_CORSAIR, 0x0c10) },
- { HID_USB_DEVICE(USB_VENDOR_ID_CORSAIR, 0x1d00) },
{ HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_RADIO_SI470X) },
{ HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_RADIO_SI4713) },
{ HID_USB_DEVICE(USB_VENDOR_ID_CMEDIA, USB_DEVICE_ID_CM109) },
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 8b046a5dfa40..c603d8c8e3d2 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -441,7 +441,7 @@ config SENSORS_BT1_PVT_ALARMS

config SENSORS_CORSAIR_CPRO
tristate "Corsair Commander Pro controller"
- depends on USB
+ depends on HID
help
If you say yes here you get support for the Corsair Commander Pro
controller.
diff --git a/drivers/hwmon/corsair-cpro.c b/drivers/hwmon/corsair-cpro.c
index fe625190e3a1..ba378574b073 100644
--- a/drivers/hwmon/corsair-cpro.c
+++ b/drivers/hwmon/corsair-cpro.c
@@ -2,16 +2,21 @@
/*
* corsair-cpro.c - Linux driver for Corsair Commander Pro
* Copyright (C) 2020 Marius Zachmann <[email protected]>
+ *
+ * This driver uses hid reports to communicate with the device to allow hidraw userspace drivers
+ * still being used. The device does not use report ids. When using hidraw and this driver
+ * simultaniously, reports could be switched.
*/

#include <linux/bitops.h>
+#include <linux/completion.h>
+#include <linux/hid.h>
#include <linux/hwmon.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/types.h>
-#include <linux/usb.h>

#define USB_VENDOR_ID_CORSAIR 0x1b1c
#define USB_PRODUCT_ID_CORSAIR_COMMANDERPRO 0x0c10
@@ -20,6 +25,7 @@
#define OUT_BUFFER_SIZE 63
#define IN_BUFFER_SIZE 16
#define LABEL_LENGTH 11
+#define REQ_TIMEOUT 300

#define CTL_GET_TMP_CNCT 0x10 /*
* returns in bytes 1-4 for each temp sensor:
@@ -62,7 +68,9 @@
#define NUM_TEMP_SENSORS 4

struct ccp_device {
- struct usb_device *udev;
+ struct hid_device *hdev;
+ struct device *hwmon_dev;
+ struct completion wait_input_report;
struct mutex mutex; /* whenever buffer is used, lock before send_usb_cmd */
u8 *buffer;
int pwm[6];
@@ -75,7 +83,7 @@ struct ccp_device {
/* send command, check for error in response, response in ccp->buffer */
static int send_usb_cmd(struct ccp_device *ccp, u8 command, u8 byte1, u8 byte2, u8 byte3)
{
- int actual_length;
+ unsigned long t;
int ret;

memset(ccp->buffer, 0x00, OUT_BUFFER_SIZE);
@@ -84,26 +92,39 @@ static int send_usb_cmd(struct ccp_device *ccp, u8 command, u8 byte1, u8 byte2,
ccp->buffer[2] = byte2;
ccp->buffer[3] = byte3;

- ret = usb_bulk_msg(ccp->udev, usb_sndintpipe(ccp->udev, 2), ccp->buffer, OUT_BUFFER_SIZE,
- &actual_length, 1000);
- if (ret)
- return ret;
+ reinit_completion(&ccp->wait_input_report);

- /* response needs to be received every time */
- ret = usb_bulk_msg(ccp->udev, usb_rcvintpipe(ccp->udev, 1), ccp->buffer, IN_BUFFER_SIZE,
- &actual_length, 1000);
- if (ret)
+ ret = hid_hw_output_report(ccp->hdev, ccp->buffer, OUT_BUFFER_SIZE);
+ if (ret < 0)
return ret;

+ t = wait_for_completion_timeout(&ccp->wait_input_report, msecs_to_jiffies(REQ_TIMEOUT));
+ if (!t)
+ return -ETIMEDOUT;
+
/* first byte of response is error code */
if (ccp->buffer[0] != 0x00) {
- dev_dbg(&ccp->udev->dev, "device response error: %d", ccp->buffer[0]);
+ hid_dbg(ccp->hdev, "device response error: %d", ccp->buffer[0]);
return -EIO;
}

return 0;
}

+static int ccp_raw_event(struct hid_device *hdev, struct hid_report *report, u8 *data, int size)
+{
+ struct ccp_device *ccp = hid_get_drvdata(hdev);
+
+ /* only copy buffer when requested */
+ if (completion_done(&ccp->wait_input_report))
+ return 0;
+
+ memcpy(ccp->buffer, data, min(IN_BUFFER_SIZE, size));
+ complete(&ccp->wait_input_report);
+
+ return 0;
+}
+
/* requests and returns single data values depending on channel */
static int get_data(struct ccp_device *ccp, int command, int channel)
{
@@ -437,57 +458,98 @@ static int get_temp_cnct(struct ccp_device *ccp)
return 0;
}

-static int ccp_probe(struct usb_interface *intf, const struct usb_device_id *id)
+static int ccp_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
- struct device *hwmon_dev;
struct ccp_device *ccp;
int ret;

- ccp = devm_kzalloc(&intf->dev, sizeof(*ccp), GFP_KERNEL);
+ ccp = devm_kzalloc(&hdev->dev, sizeof(*ccp), GFP_KERNEL);
if (!ccp)
return -ENOMEM;

- ccp->buffer = devm_kmalloc(&intf->dev, OUT_BUFFER_SIZE, GFP_KERNEL);
+ ccp->buffer = devm_kmalloc(&hdev->dev, OUT_BUFFER_SIZE, GFP_KERNEL);
if (!ccp->buffer)
return -ENOMEM;

+ ret = hid_parse(hdev);
+ if (ret)
+ return ret;
+
+ ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
+ if (ret)
+ return ret;
+
+ ret = hid_hw_open(hdev);
+ if (ret)
+ goto out_hw_stop;
+
+ ccp->hdev = hdev;
+ hid_set_drvdata(hdev, ccp);
mutex_init(&ccp->mutex);
+ init_completion(&ccp->wait_input_report);

- ccp->udev = interface_to_usbdev(intf);
+ hid_device_io_start(hdev);

/* temp and fan connection status only updates when device is powered on */
ret = get_temp_cnct(ccp);
if (ret)
- return ret;
+ goto out_hw_close;

ret = get_fan_cnct(ccp);
if (ret)
- return ret;
+ goto out_hw_close;
+ ccp->hwmon_dev = hwmon_device_register_with_info(&hdev->dev, "corsaircpro",
+ ccp, &ccp_chip_info, 0);
+ if (IS_ERR(ccp->hwmon_dev)) {
+ ret = PTR_ERR(ccp->hwmon_dev);
+ goto out_hw_close;
+ }

- hwmon_dev = devm_hwmon_device_register_with_info(&intf->dev, "corsaircpro", ccp,
- &ccp_chip_info, 0);
+ return 0;

- return PTR_ERR_OR_ZERO(hwmon_dev);
+out_hw_close:
+ hid_hw_close(hdev);
+out_hw_stop:
+ hid_hw_stop(hdev);
+ return ret;
}

-static void ccp_disconnect(struct usb_interface *intf)
+static void ccp_remove(struct hid_device *hdev)
{
+ struct ccp_device *ccp = hid_get_drvdata(hdev);
+
+ hwmon_device_unregister(ccp->hwmon_dev);
+ hid_hw_close(hdev);
+ hid_hw_stop(hdev);
}

-static const struct usb_device_id ccp_devices[] = {
- { USB_DEVICE(USB_VENDOR_ID_CORSAIR, USB_PRODUCT_ID_CORSAIR_COMMANDERPRO) },
- { USB_DEVICE(USB_VENDOR_ID_CORSAIR, USB_PRODUCT_ID_CORSAIR_1000D) },
+static const struct hid_device_id ccp_devices[] = {
+ { HID_USB_DEVICE(USB_VENDOR_ID_CORSAIR, USB_PRODUCT_ID_CORSAIR_COMMANDERPRO) },
+ { HID_USB_DEVICE(USB_VENDOR_ID_CORSAIR, USB_PRODUCT_ID_CORSAIR_1000D) },
{ }
};

-static struct usb_driver ccp_driver = {
+static struct hid_driver ccp_driver = {
.name = "corsair-cpro",
+ .id_table = ccp_devices,
.probe = ccp_probe,
- .disconnect = ccp_disconnect,
- .id_table = ccp_devices
+ .remove = ccp_remove,
+ .raw_event = ccp_raw_event,
};

-MODULE_DEVICE_TABLE(usb, ccp_devices);
+MODULE_DEVICE_TABLE(hid, ccp_devices);
MODULE_LICENSE("GPL");

-module_usb_driver(ccp_driver);
+static int __init ccp_init(void)
+{
+ return hid_register_driver(&ccp_driver);
+}
+
+static void __exit ccp_exit(void)
+{
+ hid_unregister_driver(&ccp_driver);
+}
+
+/* make sure it is loaded after hid */
+late_initcall(ccp_init);
+module_exit(ccp_exit);
--
2.27.0


2020-07-15 15:36:21

by Guenter Roeck

[permalink] [raw]
Subject: Re: [PATCH v2] hwmon: corsair-cpro: Change to HID driver

On 7/15/20 8:14 AM, Marius Zachmann wrote:
> This changes corsair-cpro to a hid driver using hid reports.
>
> Signed-off-by: Marius Zachmann <[email protected]>
>
> ---

[ ... ]

> -static const struct usb_device_id ccp_devices[] = {
> - { USB_DEVICE(USB_VENDOR_ID_CORSAIR, USB_PRODUCT_ID_CORSAIR_COMMANDERPRO) },
> - { USB_DEVICE(USB_VENDOR_ID_CORSAIR, USB_PRODUCT_ID_CORSAIR_1000D) },
> +static const struct hid_device_id ccp_devices[] = {
> + { HID_USB_DEVICE(USB_VENDOR_ID_CORSAIR, USB_PRODUCT_ID_CORSAIR_COMMANDERPRO) },
> + { HID_USB_DEVICE(USB_VENDOR_ID_CORSAIR, USB_PRODUCT_ID_CORSAIR_1000D) },
> { }
> };
>
> -static struct usb_driver ccp_driver = {
> +static struct hid_driver ccp_driver = {
> .name = "corsair-cpro",
> + .id_table = ccp_devices,
> .probe = ccp_probe,
> - .disconnect = ccp_disconnect,
> - .id_table = ccp_devices
> + .remove = ccp_remove,
> + .raw_event = ccp_raw_event,
> };
>
> -MODULE_DEVICE_TABLE(usb, ccp_devices);
> +MODULE_DEVICE_TABLE(hid, ccp_devices);
> MODULE_LICENSE("GPL");
>
> -module_usb_driver(ccp_driver);
> +static int __init ccp_init(void)
> +{
> + return hid_register_driver(&ccp_driver);
> +}
> +
> +static void __exit ccp_exit(void)
> +{
> + hid_unregister_driver(&ccp_driver);
> +}
> +
> +/* make sure it is loaded after hid */
> +late_initcall(ccp_init);
> +module_exit(ccp_exit);

Sorry for not noticing before, but can you use module_hid_driver() ?
That seems to work for other hid drivers.

Thanks,
Guenter

2020-07-15 19:14:20

by Marius Zachmann

[permalink] [raw]
Subject: Re: [PATCH v2] hwmon: corsair-cpro: Change to HID driver

On 15.07.20 at 17:35:08 CEST, Guenter Roeck wrote
> On 7/15/20 8:14 AM, Marius Zachmann wrote:
> > This changes corsair-cpro to a hid driver using hid reports.
> >
> > Signed-off-by: Marius Zachmann <[email protected]>
> >
> > ---
>
...
> > -module_usb_driver(ccp_driver);
> > +static int __init ccp_init(void)
> > +{
> > + return hid_register_driver(&ccp_driver);
> > +}
> > +
> > +static void __exit ccp_exit(void)
> > +{
> > + hid_unregister_driver(&ccp_driver);
> > +}
> > +
> > +/* make sure it is loaded after hid */
> > +late_initcall(ccp_init);
> > +module_exit(ccp_exit);
>
> Sorry for not noticing before, but can you use module_hid_driver() ?
> That seems to work for other hid drivers.
>
> Thanks,
> Guenter
>

When using module_hid_driver() and compiling the driver as built-in
the driver init function will get called before hid and fail registering
the driver. late_initcall forces it to be loaded after hid.

Greetings,
Marius


2020-07-15 19:51:45

by Guenter Roeck

[permalink] [raw]
Subject: Re: [PATCH v2] hwmon: corsair-cpro: Change to HID driver

On 7/15/20 12:12 PM, Marius Zachmann wrote:
> On 15.07.20 at 17:35:08 CEST, Guenter Roeck wrote
>> On 7/15/20 8:14 AM, Marius Zachmann wrote:
>>> This changes corsair-cpro to a hid driver using hid reports.
>>>
>>> Signed-off-by: Marius Zachmann <[email protected]>
>>>
>>> ---
>>
> ...
>>> -module_usb_driver(ccp_driver);
>>> +static int __init ccp_init(void)
>>> +{
>>> + return hid_register_driver(&ccp_driver);
>>> +}
>>> +
>>> +static void __exit ccp_exit(void)
>>> +{
>>> + hid_unregister_driver(&ccp_driver);
>>> +}
>>> +
>>> +/* make sure it is loaded after hid */
>>> +late_initcall(ccp_init);
>>> +module_exit(ccp_exit);
>>
>> Sorry for not noticing before, but can you use module_hid_driver() ?
>> That seems to work for other hid drivers.
>>
>> Thanks,
>> Guenter
>>
>
> When using module_hid_driver() and compiling the driver as built-in
> the driver init function will get called before hid and fail registering
> the driver. late_initcall forces it to be loaded after hid.
>

That seems odd. Why does no other hid driver have that problem ?
Your argument is pretty much that module_hid_driver() would not work,
which seems unlikely.

Thanks,
Guenter

2020-07-15 19:56:43

by Marius Zachmann

[permalink] [raw]
Subject: Re: [PATCH v2] hwmon: corsair-cpro: Change to HID driver

On 15.07.20 at 21:49:59 CEST, Guenter Roeck wrote
> On 7/15/20 12:12 PM, Marius Zachmann wrote:
> > On 15.07.20 at 17:35:08 CEST, Guenter Roeck wrote
> >> On 7/15/20 8:14 AM, Marius Zachmann wrote:
> >>> This changes corsair-cpro to a hid driver using hid reports.
> >>>
> >>> Signed-off-by: Marius Zachmann <[email protected]>
> >>>
> >>> ---
> >>
> > ...
> >>> -module_usb_driver(ccp_driver);
> >>> +static int __init ccp_init(void)
> >>> +{
> >>> + return hid_register_driver(&ccp_driver);
> >>> +}
> >>> +
> >>> +static void __exit ccp_exit(void)
> >>> +{
> >>> + hid_unregister_driver(&ccp_driver);
> >>> +}
> >>> +
> >>> +/* make sure it is loaded after hid */
> >>> +late_initcall(ccp_init);
> >>> +module_exit(ccp_exit);
> >>
> >> Sorry for not noticing before, but can you use module_hid_driver() ?
> >> That seems to work for other hid drivers.
> >>
> >> Thanks,
> >> Guenter
> >>
> >
> > When using module_hid_driver() and compiling the driver as built-in
> > the driver init function will get called before hid and fail registering
> > the driver. late_initcall forces it to be loaded after hid.
> >
>
> That seems odd. Why does no other hid driver have that problem ?
> Your argument is pretty much that module_hid_driver() would not work,
> which seems unlikely.
>
> Thanks,
> Guenter
>

The order of initcalls is determined by the build order. Hwmon subsystem
gets build before hid subsystem and therefore the initcalls are earlier
than hid. But hid_register_driver needs the hid driver to be there.

Greetings
Marius



2020-07-15 20:12:15

by Guenter Roeck

[permalink] [raw]
Subject: Re: [PATCH v2] hwmon: corsair-cpro: Change to HID driver

On 7/15/20 12:55 PM, Marius Zachmann wrote:
> On 15.07.20 at 21:49:59 CEST, Guenter Roeck wrote
>> On 7/15/20 12:12 PM, Marius Zachmann wrote:
>>> On 15.07.20 at 17:35:08 CEST, Guenter Roeck wrote
>>>> On 7/15/20 8:14 AM, Marius Zachmann wrote:
>>>>> This changes corsair-cpro to a hid driver using hid reports.
>>>>>
>>>>> Signed-off-by: Marius Zachmann <[email protected]>
>>>>>
>>>>> ---
>>>>
>>> ...
>>>>> -module_usb_driver(ccp_driver);
>>>>> +static int __init ccp_init(void)
>>>>> +{
>>>>> + return hid_register_driver(&ccp_driver);
>>>>> +}
>>>>> +
>>>>> +static void __exit ccp_exit(void)
>>>>> +{
>>>>> + hid_unregister_driver(&ccp_driver);
>>>>> +}
>>>>> +
>>>>> +/* make sure it is loaded after hid */
>>>>> +late_initcall(ccp_init);
>>>>> +module_exit(ccp_exit);
>>>>
>>>> Sorry for not noticing before, but can you use module_hid_driver() ?
>>>> That seems to work for other hid drivers.
>>>>
>>>> Thanks,
>>>> Guenter
>>>>
>>>
>>> When using module_hid_driver() and compiling the driver as built-in
>>> the driver init function will get called before hid and fail registering
>>> the driver. late_initcall forces it to be loaded after hid.
>>>
>>
>> That seems odd. Why does no other hid driver have that problem ?
>> Your argument is pretty much that module_hid_driver() would not work,
>> which seems unlikely.
>>
>> Thanks,
>> Guenter
>>
>
> The order of initcalls is determined by the build order. Hwmon subsystem
> gets build before hid subsystem and therefore the initcalls are earlier
> than hid. But hid_register_driver needs the hid driver to be there.
>
Hmm. I am not happy, but I guess we'll have to live with it.

Can you add the detailed explanation to the comment above ?
"make sure it is loaded after hid" doesn't tell the whole story,
and I want to avoid having to deal with "cleanup" patches later.

Alternatively, I wonder if it would make sense to force
this driver to be built as module. Have you thought about that ?

Thanks,
Guenter

2020-07-15 20:24:04

by Marius Zachmann

[permalink] [raw]
Subject: Re: [PATCH v2] hwmon: corsair-cpro: Change to HID driver

On 15.07.20 at 22:11:39 CEST, Guenter Roeck wrote
> On 7/15/20 12:55 PM, Marius Zachmann wrote:
> > On 15.07.20 at 21:49:59 CEST, Guenter Roeck wrote
> >> On 7/15/20 12:12 PM, Marius Zachmann wrote:
> >>> On 15.07.20 at 17:35:08 CEST, Guenter Roeck wrote
> >>>> On 7/15/20 8:14 AM, Marius Zachmann wrote:
> >>>>> This changes corsair-cpro to a hid driver using hid reports.
> >>>>>
> >>>>> Signed-off-by: Marius Zachmann <[email protected]>
> >>>>>
> >>>>> ---
> >>>>
> >>> ...
> >>>>> -module_usb_driver(ccp_driver);
> >>>>> +static int __init ccp_init(void)
> >>>>> +{
> >>>>> + return hid_register_driver(&ccp_driver);
> >>>>> +}
> >>>>> +
> >>>>> +static void __exit ccp_exit(void)
> >>>>> +{
> >>>>> + hid_unregister_driver(&ccp_driver);
> >>>>> +}
> >>>>> +
> >>>>> +/* make sure it is loaded after hid */
> >>>>> +late_initcall(ccp_init);
> >>>>> +module_exit(ccp_exit);
> >>>>
> >>>> Sorry for not noticing before, but can you use module_hid_driver() ?
> >>>> That seems to work for other hid drivers.
> >>>>
> >>>> Thanks,
> >>>> Guenter
> >>>>
> >>>
> >>> When using module_hid_driver() and compiling the driver as built-in
> >>> the driver init function will get called before hid and fail registering
> >>> the driver. late_initcall forces it to be loaded after hid.
> >>>
> >>
> >> That seems odd. Why does no other hid driver have that problem ?
> >> Your argument is pretty much that module_hid_driver() would not work,
> >> which seems unlikely.
> >>
> >> Thanks,
> >> Guenter
> >>
> >
> > The order of initcalls is determined by the build order. Hwmon subsystem
> > gets build before hid subsystem and therefore the initcalls are earlier
> > than hid. But hid_register_driver needs the hid driver to be there.
> >
> Hmm. I am not happy, but I guess we'll have to live with it.
>
> Can you add the detailed explanation to the comment above ?
> "make sure it is loaded after hid" doesn't tell the whole story,
> and I want to avoid having to deal with "cleanup" patches later.
>
> Alternatively, I wonder if it would make sense to force
> this driver to be built as module. Have you thought about that ?
>
> Thanks,
> Guenter
>

I am also not happy about this and thought about this, but I
think late_initcall is the least ugly solution to this.
I will add a more detailed explanation.

Greetings
Marius