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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/usb/gadget/usbstring.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/usb/gadget/usbstring.c')
| -rw-r--r-- | drivers/usb/gadget/usbstring.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/drivers/usb/gadget/usbstring.c b/drivers/usb/gadget/usbstring.c new file mode 100644 index 000000000..37a2f1b61 --- /dev/null +++ b/drivers/usb/gadget/usbstring.c @@ -0,0 +1,91 @@ +// SPDX-License-Identifier: LGPL-2.1+ +/* + * Copyright (C) 2003 David Brownell + */ + +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/list.h> +#include <linux/string.h> +#include <linux/device.h> +#include <linux/nls.h> + +#include <linux/usb/ch9.h> +#include <linux/usb/gadget.h> + + +/** + * usb_gadget_get_string - fill out a string descriptor + * @table: of c strings encoded using UTF-8 + * @id: string id, from low byte of wValue in get string descriptor + * @buf: at least 256 bytes, must be 16-bit aligned + * + * Finds the UTF-8 string matching the ID, and converts it into a + * string descriptor in utf16-le. + * Returns length of descriptor (always even) or negative errno + * + * If your driver needs stings in multiple languages, you'll probably + * "switch (wIndex) { ... }" in your ep0 string descriptor logic, + * using this routine after choosing which set of UTF-8 strings to use. + * Note that US-ASCII is a strict subset of UTF-8; any string bytes with + * the eighth bit set will be multibyte UTF-8 characters, not ISO-8859/1 + * characters (which are also widely used in C strings). + */ +int +usb_gadget_get_string (const struct usb_gadget_strings *table, int id, u8 *buf) +{ + struct usb_string *s; + int len; + + /* descriptor 0 has the language id */ + if (id == 0) { + buf [0] = 4; + buf [1] = USB_DT_STRING; + buf [2] = (u8) table->language; + buf [3] = (u8) (table->language >> 8); + return 4; + } + for (s = table->strings; s && s->s; s++) + if (s->id == id) + break; + + /* unrecognized: stall. */ + if (!s || !s->s) + return -EINVAL; + + /* string descriptors have length, tag, then UTF16-LE text */ + len = min_t(size_t, USB_MAX_STRING_LEN, strlen(s->s)); + len = utf8s_to_utf16s(s->s, len, UTF16_LITTLE_ENDIAN, + (wchar_t *) &buf[2], USB_MAX_STRING_LEN); + if (len < 0) + return -EINVAL; + buf [0] = (len + 1) * 2; + buf [1] = USB_DT_STRING; + return buf [0]; +} +EXPORT_SYMBOL_GPL(usb_gadget_get_string); + +/** + * usb_validate_langid - validate usb language identifiers + * @langid: usb language identifier + * + * Returns true for valid language identifier, otherwise false. + */ +bool usb_validate_langid(u16 langid) +{ + u16 primary_lang = langid & 0x3ff; /* bit [9:0] */ + u16 sub_lang = langid >> 10; /* bit [15:10] */ + + switch (primary_lang) { + case 0: + case 0x62 ... 0xfe: + case 0x100 ... 0x3ff: + return false; + } + if (!sub_lang) + return false; + + return true; +} +EXPORT_SYMBOL_GPL(usb_validate_langid); |
