Re: [PATCH v3] HID: sb0540: add support for Creative SB0540 IR receivers

From: Benjamin Tissoires
Date: Mon Jul 01 2019 - 05:45:22 EST


Hi Bastien,

On Wed, Jun 26, 2019 at 4:07 PM Bastien Nocera <hadess@xxxxxxxxxx> wrote:
>
> From: Bastien Nocera <bnocera@xxxxxxxxxx>
>
> Add a new hid driver for the Creative SB0540 IR receiver. This receiver
> is usually coupled with an RM-1500 or an RM-1800 remote control.
>
> The scrollwheels on the RM-1800 remote are not bound, as they are
> labelled for specific audio controls that don't usually exist on most
> systems. They can be remapped using standard Linux keyboard
> remapping tools.

Much better commit message :)
Thanks!

I have a few nitpicks however

>
> Signed-off-by: Bastien Nocera <bnocera@xxxxxxxxxx>
> ---
> drivers/hid/Kconfig | 9 ++
> drivers/hid/Makefile | 1 +
> drivers/hid/hid-creative-sb0540.c | 254 ++++++++++++++++++++++++++++++
> drivers/hid/hid-ids.h | 1 +
> 4 files changed, 265 insertions(+)
> create mode 100644 drivers/hid/hid-creative-sb0540.c
>
> diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
> index 3872e03d9a59..f16c4bd822e4 100644
> --- a/drivers/hid/Kconfig
> +++ b/drivers/hid/Kconfig
> @@ -273,6 +273,15 @@ config HID_CP2112
> and gpiochip to expose these functions of the CP2112. The
> customizable USB descriptor fields are exposed as sysfs attributes.
>
> +config HID_CREATIVE_SB0540
> + tristate "Creative SB0540 infrared receiver"
> + depends on USB_HID
> + ---help---

checkpatch.pl complains here that new help texts should use "help" not
"---help---"

And BTW, checkpatch.pl complains *a lot*, so please fix most of the
warnings in the next submission (not sure you can go to 0 for a new
driver, but you should be able to get rid of most of them).

> + Support for Creative infrared SB0540-compatible remote controls, such
> + as the RM-1500 and RM-1800 remotes.
> +
> + Say Y here if you want support for Creative SB0540 infrared receiver.
> +
> config HID_CYPRESS
> tristate "Cypress mouse and barcode readers"
> depends on HID
> diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
> index cc5d827c9164..1ad662fe37b6 100644
> --- a/drivers/hid/Makefile
> +++ b/drivers/hid/Makefile
> @@ -27,6 +27,7 @@ obj-$(CONFIG_HID_ALPS) += hid-alps.o
> obj-$(CONFIG_HID_ACRUX) += hid-axff.o
> obj-$(CONFIG_HID_APPLE) += hid-apple.o
> obj-$(CONFIG_HID_APPLEIR) += hid-appleir.o
> +obj-$(CONFIG_HID_CREATIVE_SB0540) += hid-creative-sb0540.c
> obj-$(CONFIG_HID_ASUS) += hid-asus.o
> obj-$(CONFIG_HID_AUREAL) += hid-aureal.o
> obj-$(CONFIG_HID_BELKIN) += hid-belkin.o
> diff --git a/drivers/hid/hid-creative-sb0540.c b/drivers/hid/hid-creative-sb0540.c
> new file mode 100644
> index 000000000000..a94542cbdd33
> --- /dev/null
> +++ b/drivers/hid/hid-creative-sb0540.c
> @@ -0,0 +1,254 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * HID driver for the Creative SB0540 receiver
> + *
> + * Copyright (C) 2019 Red Hat Inc. All Rights Reserved
> + *
> + */
> +
> +#include <linux/device.h>
> +#include <linux/hid.h>
> +#include <linux/module.h>
> +#include "hid-ids.h"
> +
> +MODULE_AUTHOR("Bastien Nocera <hadess@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("HID Creative SB0540 receiver");
> +MODULE_LICENSE("GPL");
> +
> +static const unsigned short creative_sb0540_key_table[] = {
> + KEY_POWER,
> + KEY_RESERVED, /* text: 24bit */
> + KEY_RESERVED, /* 24bit wheel up */
> + KEY_RESERVED, /* 24bit wheel down */
> + KEY_RESERVED, /* text: CMSS */
> + KEY_RESERVED, /* CMSS wheel Up */
> + KEY_RESERVED, /* CMSS wheel Down */
> + KEY_RESERVED, /* text: EAX */
> + KEY_RESERVED, /* EAX wheel up */
> + KEY_RESERVED, /* EAX wheel down */
> + KEY_RESERVED, /* text: 3D Midi */
> + KEY_RESERVED, /* 3D Midi wheel up */
> + KEY_RESERVED, /* 3D Midi wheel down */
> + KEY_MUTE,
> + KEY_VOLUMEUP,
> + KEY_VOLUMEDOWN,
> + KEY_UP,
> + KEY_LEFT,
> + KEY_RIGHT,
> + KEY_REWIND,
> + KEY_OK,
> + KEY_FASTFORWARD,
> + KEY_DOWN,
> + KEY_AGAIN, /* text: Return, symbol: Jump to */
> + KEY_PLAY, /* text: Start */
> + KEY_ESC, /* text: Cancel */
> + KEY_RECORD,
> + KEY_OPTION,
> + KEY_MENU, /* text: Display */
> + KEY_PREVIOUS,
> + KEY_PLAYPAUSE,
> + KEY_NEXT,
> + KEY_SLOW,
> + KEY_STOP,
> + KEY_NUMERIC_1,
> + KEY_NUMERIC_2,
> + KEY_NUMERIC_3,
> + KEY_NUMERIC_4,
> + KEY_NUMERIC_5,
> + KEY_NUMERIC_6,
> + KEY_NUMERIC_7,
> + KEY_NUMERIC_8,
> + KEY_NUMERIC_9,
> + KEY_NUMERIC_0
> +};
> +
> +/* Codes and keys from lirc's
> + * remotes/creative/lircd.conf.alsa_usb
> + * order and size must match creative_sb0540_key_table[] above */

Please follow the kernel coding style:
/*
* Codes and keys from lirc's
* remotes/creative/lircd.conf.alsa_usb
* order and size must match creative_sb0540_key_table[] above
*/

And same for all the multi-line comments.

> +static const unsigned short creative_sb0540_codes[] = {
> + 0x619E,
> + 0x916E,
> + 0x926D,
> + 0x936C,
> + 0x718E,
> + 0x946B,
> + 0x956A,
> + 0x8C73,
> + 0x9669,
> + 0x9768,
> + 0x9867,
> + 0x9966,
> + 0x9A65,
> + 0x6E91,
> + 0x629D,
> + 0x639C,
> + 0x7B84,
> + 0x6B94,
> + 0x728D,
> + 0x8778,
> + 0x817E,
> + 0x758A,
> + 0x8D72,
> + 0x8E71,
> + 0x8877,
> + 0x7C83,
> + 0x738C,
> + 0x827D,
> + 0x7689,
> + 0x7F80,
> + 0x7986,
> + 0x7A85,
> + 0x7D82,
> + 0x857A,
> + 0x8B74,
> + 0x8F70,
> + 0x906F,
> + 0x8A75,
> + 0x847B,
> + 0x7887,
> + 0x8976,
> + 0x837C,
> + 0x7788,
> + 0x807F
> +};
> +
> +struct creative_sb0540 {
> + struct input_dev *input_dev;
> + struct hid_device *hid;
> + unsigned short keymap[ARRAY_SIZE(creative_sb0540_key_table)];
> +};
> +
> +static inline u64 reverse(u64 data, int bits)
> +{
> + int i;
> + u64 c;
> +
> + c = 0;
> + for (i = 0; i < bits; i++) {
> + c |= (u64) (((data & (((u64) 1) << i)) ? 1 : 0)) << (bits - 1 - i);
> + }
> + return (c);
> +}
> +
> +static int get_key(struct creative_sb0540 *creative_sb0540, u64 keycode)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(creative_sb0540_codes); i++) {
> + if (creative_sb0540_codes[i] == keycode)
> + return creative_sb0540->keymap[i];
> + }
> +
> + return 0;
> +
> +}
> +
> +static int creative_sb0540_raw_event(struct hid_device *hid, struct hid_report *report,
> + u8 *data, int len)
> +{
> + struct creative_sb0540 *creative_sb0540 = hid_get_drvdata(hid);
> + u64 code, main_code;
> + int key;
> +
> + if (len != 6)
> + goto out;
> +
> + /* From daemons/hw_hiddev.c sb0540_rec() in lirc */
> + code = reverse(data[5], 8);
> + main_code = (code << 8) + ((~code) & 0xff);
> +
> + /* Flip to get values in the same format as
> + * remotes/creative/lircd.conf.alsa_usb in lirc */
> + main_code = ((main_code & 0xff) << 8) + ((main_code & 0xff00) >> 8);
> +
> + key = get_key(creative_sb0540, main_code);
> + if (key == 0 || key == KEY_RESERVED) {
> + hid_err(hid, "Could not get a key for main_code %llX\n", main_code);
> + goto out;

I don't really like the got out here.

Why not changing the condition above to
if (key && key != KEY_RESERVED) and include the block below in the true case?

> + }
> +
> + input_report_key(creative_sb0540->input_dev, key, 1);
> + input_report_key(creative_sb0540->input_dev, key, 0);
> + input_sync(creative_sb0540->input_dev);
> +
> +out:
> + /* let hidraw and hiddev handle the report */
> + return 0;
> +}
> +
> +static int creative_sb0540_input_configured(struct hid_device *hid,
> + struct hid_input *hidinput)
> +{
> + struct input_dev *input_dev = hidinput->input;
> + struct creative_sb0540 *creative_sb0540 = hid_get_drvdata(hid);
> + int i;
> +
> + creative_sb0540->input_dev = input_dev;
> +
> + input_dev->keycode = creative_sb0540->keymap;
> + input_dev->keycodesize = sizeof(unsigned short);
> + input_dev->keycodemax = ARRAY_SIZE(creative_sb0540->keymap);
> +
> + input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_REP);
> +
> + memcpy(creative_sb0540->keymap, creative_sb0540_key_table, sizeof(creative_sb0540->keymap));
> + for (i = 0; i < ARRAY_SIZE(creative_sb0540_key_table); i++)
> + set_bit(creative_sb0540->keymap[i], input_dev->keybit);
> + clear_bit(KEY_RESERVED, input_dev->keybit);
> +
> + return 0;
> +}
> +
> +static int creative_sb0540_input_mapping(struct hid_device *hid,
> + struct hid_input *hi, struct hid_field *field,
> + struct hid_usage *usage, unsigned long **bit, int *max)
> +{

Please add a comment here that we are remapping them ourselves, so we
can skip the hid-input processing.

> + return -1;
> +}
> +
> +static int creative_sb0540_probe(struct hid_device *hid, const struct hid_device_id *id)
> +{
> + int ret;
> + struct creative_sb0540 *creative_sb0540;
> +
> + creative_sb0540 = devm_kzalloc(&hid->dev, sizeof(struct creative_sb0540), GFP_KERNEL);
> + if (!creative_sb0540)
> + return -ENOMEM;
> +
> + creative_sb0540->hid = hid;
> +
> + /* force input as some remotes bypass the input registration */
> + hid->quirks |= HID_QUIRK_HIDINPUT_FORCE;

Does this still applies to your remote?

Cheers,
Benjamin

> +
> + hid_set_drvdata(hid, creative_sb0540);
> +
> + ret = hid_parse(hid);
> + if (ret) {
> + hid_err(hid, "parse failed\n");
> + return ret;
> + }
> +
> + ret = hid_hw_start(hid, HID_CONNECT_DEFAULT);
> + if (ret) {
> + hid_err(hid, "hw start failed\n");
> + return ret;
> + }
> +
> + return ret;
> +}
> +
> +static const struct hid_device_id creative_sb0540_devices[] = {
> + { HID_USB_DEVICE(USB_VENDOR_ID_CREATIVELABS, USB_DEVICE_ID_CREATIVE_SB0540) },
> + { }
> +};
> +MODULE_DEVICE_TABLE(hid, creative_sb0540_devices);
> +
> +static struct hid_driver creative_sb0540_driver = {
> + .name = "creative-sb0540",
> + .id_table = creative_sb0540_devices,
> + .raw_event = creative_sb0540_raw_event,
> + .input_configured = creative_sb0540_input_configured,
> + .probe = creative_sb0540_probe,
> + .input_mapping = creative_sb0540_input_mapping,
> +};
> +module_hid_driver(creative_sb0540_driver);
> diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
> index 826324997686..206b7065da86 100644
> --- a/drivers/hid/hid-ids.h
> +++ b/drivers/hid/hid-ids.h
> @@ -312,6 +312,7 @@
> #define USB_VENDOR_ID_CREATIVELABS 0x041e
> #define USB_DEVICE_ID_CREATIVE_SB_OMNI_SURROUND_51 0x322c
> #define USB_DEVICE_ID_PRODIKEYS_PCMIDI 0x2801
> +#define USB_DEVICE_ID_CREATIVE_SB0540 0x3100
>
> #define USB_VENDOR_ID_CVTOUCH 0x1ff7
> #define USB_DEVICE_ID_CVTOUCH_SCREEN 0x0013
> --
> 2.21.0
>