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From: Kenneth Albanowski To: "open list:HID CORE LAYER" Cc: Dmitry Torokhov , Benjamin Tissoires , Jiri Kosina , Peter Hutterer , Jason Gerecke , Kenneth Albanowski Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org Extends hid-core to process HID fields larger than 32 bits, by storing them as multiple consecutive 32-bit values. hid-input and hid-debug are specifically changed to match. Currently, no other hid consumers get an interface to see fields larger than 32 bits. All existing code, including hid-input processing, will by default see the least significant 32-bits of the field, so they have unchanged behaviour (sign extension does not change: for any field longer than 32 bits, extension was already a no-op, so the least significant 32-bit value will be identical. The most significant value, at the far end, will now be extended to fill its 32-bit value.) Logical min/max interaction with larger fields is limited, as min/max and other item parameters can only be described with 32-bit values (sometimes signed). hid-input is expected to ignore min/max in scenarios where a specific larger field is involved. hid-debug 'events' debugfs text report format is changed, but only for HID fields larger than 32 bits. Signed-off-by: Kenneth Albanowski --- Documentation/hid/hiddev.rst | 6 ++- drivers/hid/hid-core.c | 80 ++++++++++++++++++++++++++---------- drivers/hid/hid-debug.c | 27 ++++++++---- drivers/hid/hid-input.c | 10 ++++- include/linux/hid-debug.h | 4 +- include/linux/hid.h | 2 +- 6 files changed, 92 insertions(+), 37 deletions(-) diff --git a/Documentation/hid/hiddev.rst b/Documentation/hid/hiddev.rst index 209e6ba4e019e..f22fcf1b55b9e 100644 --- a/Documentation/hid/hiddev.rst +++ b/Documentation/hid/hiddev.rst @@ -72,8 +72,10 @@ The hiddev API uses a read() interface, and a set of ioctl() calls. HID devices exchange data with the host computer using data bundles called "reports". Each report is divided into "fields", -each of which can have one or more "usages". In the hid-core, -each one of these usages has a single signed 32 bit value. +each of which can have one or more "usages". Each of these usages +has a value, usually a 32 bit or smaller signed value. (The +hid-core can process larger values, but these are not currently +exposed through hiddev.) read(): ------- diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 19b2b0aae0c7e..e588c3a35a593 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -86,22 +86,35 @@ struct hid_report *hid_register_report(struct hid_device *device, } EXPORT_SYMBOL_GPL(hid_register_report); +// How many 32-bit values are needed to store a field? +static unsigned hid_field_size_in_values(unsigned flags, unsigned size_in_bits) +{ + if (!(flags & HID_MAIN_ITEM_VARIABLE)) { + return 1; + } else { + return DIV_ROUND_UP(size_in_bits, 32); + } +} + /* * Register a new field for this report. */ -static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages) +static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages, unsigned flags, unsigned size_in_bits) { struct hid_field *field; + unsigned size_in_values; if (report->maxfield == HID_MAX_FIELDS) { hid_err(report->device, "too many fields in report\n"); return NULL; } + size_in_values = hid_field_size_in_values(flags, size_in_bits); + field = kzalloc((sizeof(struct hid_field) + usages * sizeof(struct hid_usage) + - usages * sizeof(unsigned)), GFP_KERNEL); + usages * size_in_values * sizeof(s32)), GFP_KERNEL); if (!field) return NULL; @@ -300,7 +313,7 @@ static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsign usages = max_t(unsigned, parser->local.usage_index, parser->global.report_count); - field = hid_register_field(report, usages); + field = hid_register_field(report, usages, flags, parser->global.report_size); if (!field) return 0; @@ -1340,6 +1353,9 @@ static u32 s32ton(__s32 value, unsigned n) * While the USB HID spec allows unlimited length bit fields in "report * descriptors", most devices never use more than 16 bits. * One model of UPS is claimed to report "LINEV" as a 32-bit field. + * Some digitizers report stylus transducer IDs as 64-bit fields. + * The outer routines will extract multiple 32-bit parts if necessary + * to retrieve an entire field. * Search linux-kernel and linux-usb-devel archives for "hid-core extract". */ @@ -1495,16 +1511,19 @@ static int hid_match_usage(struct hid_device *hid, struct hid_usage *usage) } static void hid_process_event(struct hid_device *hid, struct hid_field *field, - struct hid_usage *usage, __s32 value, int interrupt) + struct hid_usage *usage, const __s32 * values, unsigned value_count, int interrupt) { struct hid_driver *hdrv = hid->driver; int ret; + if (unlikely(value_count == 0)) + return; + if (!list_empty(&hid->debug_list)) - hid_dump_input(hid, usage, value); + hid_dump_input(hid, usage, values, value_count); if (hdrv && hdrv->event && hid_match_usage(hid, usage)) { - ret = hdrv->event(hid, field, usage, value); + ret = hdrv->event(hid, field, usage, values[0]); if (ret != 0) { if (ret < 0) hid_err(hid, "%s's event failed with %d\n", @@ -1514,9 +1533,9 @@ static void hid_process_event(struct hid_device *hid, struct hid_field *field, } if (hid->claimed & HID_CLAIMED_INPUT) - hidinput_hid_event(hid, field, usage, value); + hidinput_hid_event(hid, field, usage, values, value_count); if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event) - hid->hiddev_hid_event(hid, field, usage, value); + hid->hiddev_hid_event(hid, field, usage, values[0]); } /* @@ -1528,24 +1547,41 @@ static void hid_process_event(struct hid_device *hid, struct hid_field *field, static void hid_input_field(struct hid_device *hid, struct hid_field *field, __u8 *data, int interrupt) { - unsigned n; + unsigned n, v; unsigned count = field->report_count; unsigned offset = field->report_offset; - unsigned size = field->report_size; + unsigned size_in_bits = field->report_size; + unsigned size_in_values; /* storage size in 32-bit values, always >= 1 */ + unsigned last_value_size_in_bits; /* bits in most significant/last value */ + unsigned bit_pos; __s32 min = field->logical_minimum; __s32 max = field->logical_maximum; __s32 *value; + static const __s32 zero = 0; + static const __s32 one = 1; + + size_in_values = hid_field_size_in_values(field->flags, size_in_bits); + last_value_size_in_bits = (size_in_bits % 32) ?: 32; - value = kmalloc_array(count, sizeof(__s32), GFP_ATOMIC); + value = kmalloc_array(count * size_in_values, sizeof(__s32), GFP_ATOMIC); if (!value) return; - for (n = 0; n < count; n++) { + for (n = 0; n < count * size_in_values; n += size_in_values) { + v = 0; + bit_pos = offset + (n * size_in_bits); + + // Extract least significant values for fields longer than 32 bits. + if (size_in_values > 1) { + for (; v < size_in_values - 1; v++, bit_pos += 32) + value[n+v] = hid_field_extract(hid, data, bit_pos, 32); + } - value[n] = min < 0 ? - snto32(hid_field_extract(hid, data, offset + n * size, - size), size) : - hid_field_extract(hid, data, offset + n * size, size); + // May need to sign extend the most significant value. + value[n+v] = min < 0 ? + sign_extend32(hid_field_extract(hid, data, bit_pos, + last_value_size_in_bits), last_value_size_in_bits) : + hid_field_extract(hid, data, bit_pos, last_value_size_in_bits); /* Ignore report if ErrorRollOver */ if (!(field->flags & HID_MAIN_ITEM_VARIABLE) && @@ -1555,10 +1591,10 @@ static void hid_input_field(struct hid_device *hid, struct hid_field *field, goto exit; } - for (n = 0; n < count; n++) { + for (n = 0; n < count * size_in_values; n += size_in_values) { if (HID_MAIN_ITEM_VARIABLE & field->flags) { - hid_process_event(hid, field, &field->usage[n], value[n], interrupt); + hid_process_event(hid, field, &field->usage[n], value + n, size_in_values, interrupt); continue; } @@ -1566,16 +1602,16 @@ static void hid_input_field(struct hid_device *hid, struct hid_field *field, && field->value[n] - min < field->maxusage && field->usage[field->value[n] - min].hid && search(value, field->value[n], count)) - hid_process_event(hid, field, &field->usage[field->value[n] - min], 0, interrupt); + hid_process_event(hid, field, &field->usage[field->value[n] - min], &zero, 1, interrupt); if (value[n] >= min && value[n] <= max && value[n] - min < field->maxusage && field->usage[value[n] - min].hid && search(field->value, value[n], count)) - hid_process_event(hid, field, &field->usage[value[n] - min], 1, interrupt); + hid_process_event(hid, field, &field->usage[value[n] - min], &one, 1, interrupt); } - memcpy(field->value, value, count * sizeof(__s32)); + memcpy(field->value, value, count * size_in_values * sizeof(__s32)); exit: kfree(value); } @@ -1662,7 +1698,7 @@ int hid_set_field(struct hid_field *field, unsigned offset, __s32 value) size = field->report_size; - hid_dump_input(field->report->device, field->usage + offset, value); + hid_dump_input(field->report->device, field->usage + offset, &value, 1); if (offset >= field->report_count) { hid_err(field->report->device, "offset (%d) exceeds report_count (%d)\n", diff --git a/drivers/hid/hid-debug.c b/drivers/hid/hid-debug.c index 9453147d020db..bc25b0e8b6b63 100644 --- a/drivers/hid/hid-debug.c +++ b/drivers/hid/hid-debug.c @@ -692,21 +692,30 @@ void hid_dump_report(struct hid_device *hid, int type, u8 *data, } EXPORT_SYMBOL_GPL(hid_dump_report); -void hid_dump_input(struct hid_device *hdev, struct hid_usage *usage, __s32 value) +void hid_dump_input(struct hid_device *hdev, struct hid_usage *usage, const __s32 *values, unsigned value_count) { char *buf; int len; + unsigned n; - buf = hid_resolv_usage(usage->hid, NULL); - if (!buf) - return; - len = strlen(buf); - snprintf(buf + len, HID_DEBUG_BUFSIZE - len - 1, " = %d\n", value); + for (n = 0; n < value_count; n++) { - hid_debug_event(hdev, buf); + buf = hid_resolv_usage(usage->hid, NULL); + if (!buf) + return; - kfree(buf); - wake_up_interruptible(&hdev->debug_wait); + len = strlen(buf); + + if (value_count == 1) + snprintf(buf + len, HID_DEBUG_BUFSIZE - len - 1, " = %d\n", values[n]); + else + snprintf(buf + len, HID_DEBUG_BUFSIZE - len - 1, "[%d] = %d (%08x)\n", n, values[n], values[n]); + + hid_debug_event(hdev, buf); + + kfree(buf); + wake_up_interruptible(&hdev->debug_wait); + } } EXPORT_SYMBOL_GPL(hid_dump_input); diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index bceccd75b488e..ee9e8d31a45ba 100644 --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c @@ -1273,10 +1273,18 @@ static void hidinput_handle_scroll(struct hid_usage *usage, input_event(input, EV_REL, usage->code, hi_res); } -void hidinput_hid_event(struct hid_device *hid, struct hid_field *field, struct hid_usage *usage, __s32 value) +void hidinput_hid_event(struct hid_device *hid, struct hid_field *field, struct hid_usage *usage, const __s32 *values, unsigned value_count) { struct input_dev *input; unsigned *quirks = &hid->quirks; + __s32 value; + + if (unlikely(value_count == 0)) + return; + + // The majority of this code was writen to only understand 32-bit sized + // values, and anything larger was truncated: we continue that tradition. + value = values[0]; if (!usage->type) return; diff --git a/include/linux/hid-debug.h b/include/linux/hid-debug.h index ea7b23d13bfdf..b4fb1a73817b4 100644 --- a/include/linux/hid-debug.h +++ b/include/linux/hid-debug.h @@ -16,7 +16,7 @@ #define HID_DEBUG_BUFSIZE 512 #define HID_DEBUG_FIFOSIZE 512 -void hid_dump_input(struct hid_device *, struct hid_usage *, __s32); +void hid_dump_input(struct hid_device *, struct hid_usage *, const __s32 *, unsigned); void hid_dump_report(struct hid_device *, int , u8 *, int); void hid_dump_device(struct hid_device *, struct seq_file *); void hid_dump_field(struct hid_field *, int, struct seq_file *); @@ -37,7 +37,7 @@ struct hid_debug_list { #else -#define hid_dump_input(a,b,c) do { } while (0) +#define hid_dump_input(a,b,c,d) do { } while (0) #define hid_dump_report(a,b,c,d) do { } while (0) #define hid_dump_device(a,b) do { } while (0) #define hid_dump_field(a,b,c) do { } while (0) diff --git a/include/linux/hid.h b/include/linux/hid.h index 59828a6080e83..8494b1995b10b 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -878,7 +878,7 @@ extern void hid_unregister_driver(struct hid_driver *); module_driver(__hid_driver, hid_register_driver, \ hid_unregister_driver) -extern void hidinput_hid_event(struct hid_device *, struct hid_field *, struct hid_usage *, __s32); +extern void hidinput_hid_event(struct hid_device *, struct hid_field *, struct hid_usage *, const __s32 *values, unsigned value_count); extern void hidinput_report_event(struct hid_device *hid, struct hid_report *report); extern int hidinput_connect(struct hid_device *hid, unsigned int force); extern void hidinput_disconnect(struct hid_device *); -- 2.31.0