Hi Dmitry, On Fri, Jan 14, 2022 at 06:31:35PM -0800, Dmitry Antipov wrote: > From: Dmitry Antipov <dmanti@xxxxxxxxxxxxx> > > This driver follows HID Over SPI Protocol Specification 1.0 available at > https://www.microsoft.com/en-us/download/details.aspx?id=103325. The > initial version of the driver does not support: 1) multi-fragment input > reports, 2) sending GET_INPUT and COMMAND output report types and > processing their respective acknowledge input reports, and 3) device > sleep power state. The driver does not use threaded interrupts and instead uses a lot of work structs, which makes it very complex. Please consider switching over to threaded interrupt handler and see if some of the work can be done in-place, I believe it will simplify the driver significantly. More random comments below. > > Signed-off-by: Dmitry Antipov <dmanti@xxxxxxxxxxxxx> > --- > arch/arm64/configs/defconfig | 1 + > drivers/hid/Kconfig | 2 + > drivers/hid/Makefile | 1 + > drivers/hid/spi-hid/Kconfig | 25 + > drivers/hid/spi-hid/Makefile | 12 + > drivers/hid/spi-hid/spi-hid-core.c | 1328 +++++++++++++++++++++++++++ > drivers/hid/spi-hid/spi-hid-core.h | 188 ++++ > drivers/hid/spi-hid/spi-hid-of.c | 148 +++ > drivers/hid/spi-hid/spi-hid-of.h | 34 + > drivers/hid/spi-hid/spi-hid_trace.h | 198 ++++ > drivers/hid/spi-hid/trace.c | 11 + > 11 files changed, 1948 insertions(+) > create mode 100644 drivers/hid/spi-hid/Kconfig > create mode 100644 drivers/hid/spi-hid/Makefile > create mode 100644 drivers/hid/spi-hid/spi-hid-core.c > create mode 100644 drivers/hid/spi-hid/spi-hid-core.h > create mode 100755 drivers/hid/spi-hid/spi-hid-of.c > create mode 100755 drivers/hid/spi-hid/spi-hid-of.h > create mode 100644 drivers/hid/spi-hid/spi-hid_trace.h > create mode 100644 drivers/hid/spi-hid/trace.c > > diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig > index f2e2b9bdd702..25249a4b0c8a 100644 > --- a/arch/arm64/configs/defconfig > +++ b/arch/arm64/configs/defconfig > @@ -805,6 +805,7 @@ CONFIG_SND_AUDIO_GRAPH_CARD=m > CONFIG_HID_MULTITOUCH=m > CONFIG_I2C_HID_ACPI=m > CONFIG_I2C_HID_OF=m > +CONFIG_SPI_HID=m > CONFIG_USB_CONN_GPIO=m > CONFIG_USB=y > CONFIG_USB_OTG=y This chunk does not belong to this patch. > diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig > index a7c78ac96270..cd2c10703fcf 100644 > --- a/drivers/hid/Kconfig > +++ b/drivers/hid/Kconfig > @@ -1262,6 +1262,8 @@ source "drivers/hid/usbhid/Kconfig" > > source "drivers/hid/i2c-hid/Kconfig" > > +source "drivers/hid/spi-hid/Kconfig" > + > source "drivers/hid/intel-ish-hid/Kconfig" > > source "drivers/hid/amd-sfh-hid/Kconfig" > diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile > index 55a6fa3eca5a..caf418dda343 100644 > --- a/drivers/hid/Makefile > +++ b/drivers/hid/Makefile > @@ -144,6 +144,7 @@ obj-$(CONFIG_USB_MOUSE) += usbhid/ > obj-$(CONFIG_USB_KBD) += usbhid/ > > obj-$(CONFIG_I2C_HID_CORE) += i2c-hid/ > +obj-$(CONFIG_SPI_HID) += spi-hid/ > > obj-$(CONFIG_INTEL_ISH_HID) += intel-ish-hid/ > obj-$(INTEL_ISH_FIRMWARE_DOWNLOADER) += intel-ish-hid/ > diff --git a/drivers/hid/spi-hid/Kconfig b/drivers/hid/spi-hid/Kconfig > new file mode 100644 > index 000000000000..37302d658162 > --- /dev/null > +++ b/drivers/hid/spi-hid/Kconfig > @@ -0,0 +1,25 @@ > +# > +# Copyright (c) 2021 Microsoft Corporation > +# > +# This program is free software; you can redistribute it and/or modify it > +# under the terms of the GNU General Public License version 2 as published by > +# the Free Software Foundation. > +# > +menu "SPI HID support" > + depends on SPI > + > +config SPI_HID > + tristate "HID over SPI transport layer" > + default n > + depends on SPI && INPUT && OF > + select HID > + help > + Say Y here if you use a keyboard, a touchpad, a touchscreen, or any > + other HID based devices which is connected to your computer via SPI. > + > + If unsure, say N. > + > + This support is also available as a module. If so, the module > + will be called spi-hid. > + > +endmenu > diff --git a/drivers/hid/spi-hid/Makefile b/drivers/hid/spi-hid/Makefile > new file mode 100644 > index 000000000000..0d34a04b5dc7 > --- /dev/null > +++ b/drivers/hid/spi-hid/Makefile > @@ -0,0 +1,12 @@ > +# > +# Copyright (c) 2021 Microsoft Corporation > +# > +# This program is free software; you can redistribute it and/or modify it > +# under the terms of the GNU General Public License version 2 as published by > +# the Free Software Foundation. > +# > +# Makefile for the SPI input drivers > +# > +CFLAGS_trace.o = -I$(src) > +obj-$(CONFIG_SPI_HID) += spi-hid.o > +spi-hid-objs := spi-hid-core.o spi-hid-of.o trace.o > diff --git a/drivers/hid/spi-hid/spi-hid-core.c b/drivers/hid/spi-hid/spi-hid-core.c > new file mode 100644 > index 000000000000..4d5a24613beb > --- /dev/null > +++ b/drivers/hid/spi-hid/spi-hid-core.c > @@ -0,0 +1,1328 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * HID over SPI protocol implementation > + * spi-hid-core.c I recommend not to put file names in comments as they tend to get stale. > + * > + * Copyright (c) 2021 Microsoft Corporation > + * > + * This code is partly based on "HID over I2C protocol implementation: > + * > + * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@xxxxxxxxx> > + * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France > + * Copyright (c) 2012 Red Hat, Inc > + * > + * which in turn is partly based on "USB HID support for Linux": > + * > + * Copyright (c) 1999 Andreas Gal > + * Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@xxxxxxx> > + * Copyright (c) 2005 Michael Haboustak <mike-@xxxxxxxxxxxx> for Concept2, Inc > + * Copyright (c) 2007-2008 Oliver Neukum > + * Copyright (c) 2006-2010 Jiri Kosina > + */ > + > +#include <linux/crc32.h> > +#include <linux/delay.h> > +#include <linux/device.h> > +#include <linux/dma-mapping.h> > +#include <linux/err.h> > +#include <linux/hid.h> > +#include <linux/input.h> > +#include <linux/interrupt.h> > +#include <linux/irq.h> > +#include <linux/jiffies.h> > +#include <linux/kernel.h> > +#include <linux/list.h> > +#include <linux/module.h> > +#include <linux/mutex.h> > +#include <linux/of.h> > +#include <linux/slab.h> > +#include <linux/spi/spi.h> > +#include <linux/string.h> > +#include <linux/wait.h> > +#include <linux/workqueue.h> > + > +#include "spi-hid-core.h" > +#include "spi-hid_trace.h" > +#include "spi-hid-of.h" > +#include "../hid-ids.h" > + > +#define SPI_HID_MAX_RESET_ATTEMPTS 3 > + > +static struct hid_ll_driver spi_hid_ll_driver; > + > +static void spi_hid_populate_read_approvals(struct spi_hid_of_config *conf, > + __u8 *header_buf, __u8 *body_buf) I think this is largely matter of preference, but usually in kernel we use u8, u16, etc, and variants with underscores are used in headers exported to userspace. > +{ > + header_buf[0] = conf->read_opcode; > + header_buf[1] = (conf->input_report_header_address >> 16) & 0xff; > + header_buf[2] = (conf->input_report_header_address >> 8) & 0xff; > + header_buf[3] = (conf->input_report_header_address >> 0) & 0xff; > + header_buf[4] = SPI_HID_READ_APPROVAL_CONSTANT; > + > + body_buf[0] = conf->read_opcode; > + body_buf[1] = (conf->input_report_body_address >> 16) & 0xff; > + body_buf[2] = (conf->input_report_body_address >> 8) & 0xff; > + body_buf[3] = (conf->input_report_body_address >> 0) & 0xff; > + body_buf[4] = SPI_HID_READ_APPROVAL_CONSTANT; > +} > + > +static void spi_hid_parse_dev_desc(struct spi_hid_device_desc_raw *raw, > + struct spi_hid_device_descriptor *desc) > +{ > + desc->hid_version = le16_to_cpu(raw->bcdVersion); > + desc->report_descriptor_length = le16_to_cpu(raw->wReportDescLength); > + desc->max_input_length = le16_to_cpu(raw->wMaxInputLength); > + desc->max_output_length = le16_to_cpu(raw->wMaxOutputLength); > + > + /* FIXME: multi-fragment not supported, field below not used */ > + desc->max_fragment_length = le16_to_cpu(raw->wMaxFragmentLength); > + > + desc->vendor_id = le16_to_cpu(raw->wVendorID); > + desc->product_id = le16_to_cpu(raw->wProductID); > + desc->version_id = le16_to_cpu(raw->wVersionID); > + desc->no_output_report_ack = le16_to_cpu(raw->wFlags) & BIT(0); > +} > + > +static void spi_hid_populate_input_header(__u8 *buf, > + struct spi_hid_input_header *header) > +{ > + header->version = buf[0] & 0xf; > + header->report_length = (buf[1] | ((buf[2] & 0x3f) << 8)) * 4; > + header->last_fragment_flag = (buf[2] & 0x40) >> 6; > + header->sync_const = buf[3]; > +} > + > +static void spi_hid_populate_input_body(__u8 *buf, > + struct spi_hid_input_body *body) > +{ > + body->report_type = buf[0]; > + body->content_length = buf[1] | (buf[2] << 8); Where possible we should use get_unaligned_le16/put_unaligned_le16/cpu_to_le16/le16_to_cpu/etc. It documents data structures better and may result in slightly better performance. > + body->content_id = buf[3]; > +} > + > +static void spi_hid_input_report_prepare(struct spi_hid_input_buf *buf, > + struct spi_hid_input_report *report) > +{ > + struct spi_hid_input_header header; > + struct spi_hid_input_body body; > + > + spi_hid_populate_input_header(buf->header, &header); > + spi_hid_populate_input_body(buf->body, &body); > + report->report_type = body.report_type; > + report->content_length = body.content_length; > + report->content_id = body.content_id; > + report->content = buf->content; > +} > + > +static void spi_hid_populate_output_header(__u8 *buf, > + struct spi_hid_of_config *conf, > + struct spi_hid_output_report *report) > +{ > + buf[0] = conf->write_opcode; > + buf[1] = (conf->output_report_address >> 16) & 0xff; > + buf[2] = (conf->output_report_address >> 8) & 0xff; > + buf[3] = (conf->output_report_address >> 0) & 0xff; > + buf[4] = report->report_type; > + buf[5] = report->content_length & 0xff; > + buf[6] = (report->content_length >> 8) & 0xff; le16... > + buf[7] = report->content_id; > +} > + > +static int spi_hid_input_async(struct spi_hid *shid, void *buf, u16 length, > + void (*complete)(void *), bool is_header) > +{ > + int ret; > + struct device *dev = &shid->spi->dev; > + > + shid->input_transfer[0].tx_buf = is_header ? shid->read_approval_header : > + shid->read_approval_body; > + shid->input_transfer[0].len = SPI_HID_READ_APPROVAL_LEN; > + > + shid->input_transfer[1].rx_buf = buf; > + shid->input_transfer[1].len = length; > + > + spi_message_init_with_transfers(&shid->input_message, > + shid->input_transfer, 2); > + > + shid->input_message.complete = complete; > + shid->input_message.context = shid; > + > + trace_spi_hid_input_async(shid, > + shid->input_transfer[0].tx_buf, > + shid->input_transfer[0].len, > + shid->input_transfer[1].rx_buf, > + shid->input_transfer[1].len, 0); > + > + ret = spi_async(shid->spi, &shid->input_message); > + if (ret) { > + dev_err(dev, "Error starting async transfer: %d, resetting\n", > + ret); > + shid->bus_error_count++; > + shid->bus_last_error = ret; > + schedule_work(&shid->error_work); > + } > + > + return ret; > +} > + > +static int spi_hid_output(struct spi_hid *shid, void *buf, u16 length) > +{ > + struct spi_transfer transfer; > + struct spi_message message; > + int ret; > + > + memset(&transfer, 0, sizeof(transfer)); > + > + transfer.tx_buf = buf; > + transfer.len = length; > + > + spi_message_init_with_transfers(&message, &transfer, 1); > + > + /* > + * REVISIT: Should output be asynchronous? > + * > + * According to Documentation/hid/hid-transport.rst, ->output_report() > + * must be implemented as an asynchronous operation. > + */ I am not quite sure what that doc means. Do they simply mean that the driver should not wait for response from the device? I think that transfer (send) can still happen synchronously. > + trace_spi_hid_output_begin(shid, transfer.tx_buf, > + transfer.len, NULL, 0, 0); > + > + ret = spi_sync(shid->spi, &message); > + > + trace_spi_hid_output_end(shid, transfer.tx_buf, > + transfer.len, NULL, 0, ret); > + > + if (ret) { > + shid->bus_error_count++; > + shid->bus_last_error = ret; > + } > + > + return ret; > +} > + > +static const char *const spi_hid_power_mode_string(u8 power_state) > +{ > + switch (power_state) { > + case SPI_HID_POWER_MODE_ON: > + return "d0"; > + case SPI_HID_POWER_MODE_SLEEP: > + return "d2"; > + case SPI_HID_POWER_MODE_OFF: > + return "d3"; > + case SPI_HID_POWER_MODE_WAKING_SLEEP: > + return "d3*"; > + default: > + return "unknown"; > + } > +} > + > +static void spi_hid_suspend(struct spi_hid *shid) > +{ > + struct device *dev = &shid->spi->dev; > + > + if (shid->power_state == SPI_HID_POWER_MODE_OFF) > + return; > + > + disable_irq(shid->spi->irq); > + shid->ready = false; > + sysfs_notify(&dev->kobj, NULL, "ready"); > + > + spi_hid_of_assert_reset(&shid->conf); Are you sure you want to have reset asserted while the device is sleeping? Is it really a reset pin, or is it actually a GPIO-controlled regulator? > + > + shid->power_state = SPI_HID_POWER_MODE_OFF; > +} > + > +static void spi_hid_resume(struct spi_hid *shid) > +{ > + if (shid->power_state == SPI_HID_POWER_MODE_ON) > + return; > + > + shid->power_state = SPI_HID_POWER_MODE_ON; > + enable_irq(shid->spi->irq); > + shid->input_transfer_pending = 0; > + > + spi_hid_of_deassert_reset(&shid->conf); > +} > + > +static struct hid_device *spi_hid_disconnect_hid(struct spi_hid *shid) > +{ > + struct hid_device *hid = shid->hid; > + > + shid->hid = NULL; Umm, why the wrapper? > + > + return hid; > +} > + > +static void spi_hid_stop_hid(struct spi_hid *shid) > +{ > + struct hid_device *hid; > + > + hid = spi_hid_disconnect_hid(shid); > + if (hid) { > + cancel_work_sync(&shid->create_device_work); > + cancel_work_sync(&shid->refresh_device_work); > + hid_destroy_device(hid); > + } > +} > + > +static void spi_hid_error_handler(struct spi_hid *shid) > +{ > + struct device *dev = &shid->spi->dev; > + int ret; > + > + if (shid->power_state == SPI_HID_POWER_MODE_OFF) > + return; > + > + if (shid->attempts++ >= SPI_HID_MAX_RESET_ATTEMPTS) { > + dev_err(dev, "unresponsive device, aborting.\n"); > + spi_hid_stop_hid(shid); > + spi_hid_of_assert_reset(&shid->conf); > + ret = spi_hid_of_power_down(&shid->conf); > + if (ret) { > + dev_err(dev, "failed to disable regulator\n"); > + shid->regulator_error_count++; > + shid->regulator_last_error = ret; > + } > + return; > + } > + > + trace_spi_hid_error_handler(shid); > + > + shid->ready = false; > + sysfs_notify(&dev->kobj, NULL, "ready"); > + > + spi_hid_of_assert_reset(&shid->conf); > + > + shid->power_state = SPI_HID_POWER_MODE_OFF; > + shid->input_transfer_pending = 0; > + cancel_work_sync(&shid->reset_work); > + > + spi_hid_of_sleep_minimal_reset_delay(&shid->conf); > + > + shid->power_state = SPI_HID_POWER_MODE_ON; > + > + spi_hid_of_deassert_reset(&shid->conf); > +} > + > +static void spi_hid_error_work(struct work_struct *work) > +{ > + struct spi_hid *shid = container_of(work, struct spi_hid, error_work); > + > + spi_hid_error_handler(shid); > +} > + > +static int spi_hid_send_output_report(struct spi_hid *shid, > + struct spi_hid_output_report *report) > +{ > + struct spi_hid_output_buf *buf = &shid->output; > + struct device *dev = &shid->spi->dev; > + u16 report_length; > + u16 padded_length; > + u8 padding; > + int ret; > + > + if (report->content_length > shid->desc.max_output_length) { > + dev_err(dev, "Output report too big, content_length 0x%x\n", > + report->content_length); > + ret = -E2BIG; > + goto out; > + } > + > + spi_hid_populate_output_header(buf->header, &shid->conf, report); > + > + if (report->content_length) > + memcpy(&buf->content, report->content, report->content_length); > + > + report_length = sizeof(buf->header) + report->content_length; > + padded_length = round_up(report_length, 4); > + padding = padded_length - report_length; > + memset(&buf->content[report->content_length], 0, padding); > + > + ret = spi_hid_output(shid, buf, padded_length); > + if (ret) { > + dev_err(dev, "Failed output transfer\n"); > + goto out; > + } > + > + return 0; > + > +out: > + return ret; > +} > + > +static int spi_hid_sync_request(struct spi_hid *shid, > + struct spi_hid_output_report *report) > +{ > + struct device *dev = &shid->spi->dev; > + int ret = 0; > + > + ret = spi_hid_send_output_report(shid, report); > + if (ret) { > + dev_err(dev, "Failed to transfer output report\n"); > + return ret; > + } > + > + mutex_unlock(&shid->lock); > + ret = wait_for_completion_interruptible_timeout(&shid->output_done, > + msecs_to_jiffies(1000)); > + mutex_lock(&shid->lock); Where is the completion reinitialized? > + if (ret == 0) { > + dev_err(dev, "Response timed out\n"); > + return -ETIMEDOUT; > + } > + > + return 0; > +} > + > +/** > + * Handle the reset response from the FW by sending a request for the device > + * descriptor. > + */ > +static void spi_hid_reset_work(struct work_struct *work) > +{ > + struct spi_hid *shid = > + container_of(work, struct spi_hid, reset_work); > + struct device *dev = &shid->spi->dev; > + struct spi_hid_output_report report = { > + .report_type = SPI_HID_OUTPUT_REPORT_TYPE_DEVICE_DESC_REQUEST, > + .content_length = 0x0, > + .content_id = SPI_HID_OUTPUT_REPORT_CONTENT_ID_DESC_REQUEST, > + .content = NULL, > + }; > + int ret; > + > + trace_spi_hid_reset_work(shid); > + > + if (shid->ready) { > + dev_err(dev, "Spontaneous FW reset!"); > + shid->ready = false; > + sysfs_notify(&dev->kobj, NULL, "ready"); > + shid->dir_count++; > + } > + > + if (shid->power_state == SPI_HID_POWER_MODE_OFF) > + return; > + > + if (flush_work(&shid->create_device_work)) > + dev_err(dev, "Reset handler waited for create_device_work"); > + > + if (flush_work(&shid->refresh_device_work)) > + dev_err(dev, "Reset handler waited for refresh_device_work"); > + > + mutex_lock(&shid->lock); > + ret = spi_hid_sync_request(shid, &report); > + mutex_unlock(&shid->lock); > + if (ret) { > + dev_WARN_ONCE(dev, true, > + "Failed to send device descriptor request\n"); > + spi_hid_error_handler(shid); > + } > +} > + > +static int spi_hid_input_report_handler(struct spi_hid *shid, > + struct spi_hid_input_buf *buf) > +{ > + struct device *dev = &shid->spi->dev; > + struct spi_hid_input_report r; > + int ret; > + > + trace_spi_hid_input_report_handler(shid); > + > + if (!shid->ready || shid->refresh_in_progress || !shid->hid) > + return 0; > + > + spi_hid_input_report_prepare(buf, &r); > + > + ret = hid_input_report(shid->hid, HID_INPUT_REPORT, > + r.content - 1, > + r.content_length + 1, 1); > + > + if (ret == -ENODEV || ret == -EBUSY) { > + dev_err(dev, "ignoring report --> %d\n", ret); > + return 0; > + } else if (ret) { > + dev_err(dev, "Bad input report, error %d\n", ret); > + } > + > + return ret; > +} > + > +static void spi_hid_response_handler(struct spi_hid *shid, > + struct spi_hid_input_buf *buf) > +{ > + trace_spi_hid_response_handler(shid); > + > + /* completion_done returns 0 if there are waiters, otherwise 1 */ > + if (completion_done(&shid->output_done)) { > + dev_err(&shid->spi->dev, "Unexpected response report\n"); > + } else { > + if (shid->input.body[0] == > + SPI_HID_INPUT_REPORT_TYPE_REPORT_DESC || > + shid->input.body[0] == > + SPI_HID_INPUT_REPORT_TYPE_GET_FEATURE_RESP) { > + size_t response_length = (shid->input.body[1] | > + (shid->input.body[2] << 8)) + > + sizeof(shid->input.body); > + memcpy(shid->response.body, shid->input.body, > + response_length); > + } > + complete(&shid->output_done); > + } > +} > + > +/* > + * This function returns the length of the report descriptor, or a negative > + * error code if something went wrong. > + */ > +static int spi_hid_report_descriptor_request(struct spi_hid *shid) > +{ > + int ret; > + struct device *dev = &shid->spi->dev; > + struct spi_hid_output_report report = { > + .report_type = SPI_HID_OUTPUT_REPORT_TYPE_REPORT_DESC_REQUEST, > + .content_length = 0, > + .content_id = SPI_HID_OUTPUT_REPORT_CONTENT_ID_DESC_REQUEST, > + .content = NULL, > + }; > + > + ret = spi_hid_sync_request(shid, &report); > + if (ret) { > + dev_err(dev, > + "Expected report descriptor not received! Error %d\n", > + ret); > + spi_hid_error_handler(shid); > + goto out; > + } > + > + ret = (shid->response.body[1] | (shid->response.body[2] << 8)); le16... > + if (ret != shid->desc.report_descriptor_length) { > + dev_err(dev, > + "Received report descriptor length doesn't match device descriptor field, using min of the two\n"); > + ret = min_t(unsigned int, ret, > + shid->desc.report_descriptor_length); > + } > +out: > + return ret; > +} > + > +static void spi_hid_process_input_report(struct spi_hid *shid, > + struct spi_hid_input_buf *buf) > +{ > + struct spi_hid_input_header header; > + struct spi_hid_input_body body; > + struct device *dev = &shid->spi->dev; > + struct spi_hid_device_desc_raw *raw; > + int ret; > + > + trace_spi_hid_process_input_report(shid); > + > + spi_hid_populate_input_header(buf->header, &header); > + spi_hid_populate_input_body(buf->body, &body); > + > + if (body.content_length > header.report_length) { > + dev_err(dev, "Bad body length %d > %d\n", body.content_length, > + header.report_length); > + schedule_work(&shid->error_work); > + return; > + } > + > + switch (body.report_type) { > + case SPI_HID_INPUT_REPORT_TYPE_DATA: > + ret = spi_hid_input_report_handler(shid, buf); > + if (ret) > + schedule_work(&shid->error_work); > + break; > + case SPI_HID_INPUT_REPORT_TYPE_RESET_RESP: > + schedule_work(&shid->reset_work); > + break; > + case SPI_HID_INPUT_REPORT_TYPE_DEVICE_DESC: > + /* Mark the completion done to avoid timeout */ > + spi_hid_response_handler(shid, buf); > + > + /* Reset attempts at every device descriptor fetch */ > + shid->attempts = 0; > + > + raw = (struct spi_hid_device_desc_raw *)buf->content; > + > + /* Validate device descriptor length before parsing */ > + if (body.content_length != SPI_HID_DEVICE_DESCRIPTOR_LENGTH) { > + dev_err(dev, > + "Invalid content length %d, expected %d\n", > + body.content_length, > + SPI_HID_DEVICE_DESCRIPTOR_LENGTH); > + schedule_work(&shid->error_work); > + break; > + } > + > + if (le16_to_cpu(raw->wDeviceDescLength) != > + SPI_HID_DEVICE_DESCRIPTOR_LENGTH) { > + dev_err(dev, > + "Invalid wDeviceDescLength %d, expected %d\n", > + raw->wDeviceDescLength, > + SPI_HID_DEVICE_DESCRIPTOR_LENGTH); > + schedule_work(&shid->error_work); > + break; > + } > + > + spi_hid_parse_dev_desc(raw, &shid->desc); > + > + if (shid->desc.hid_version != SPI_HID_SUPPORTED_VERSION) { > + dev_err(dev, > + "Unsupported device descriptor version %4x\n", > + shid->desc.hid_version); > + schedule_work(&shid->error_work); > + break; > + } > + > + if (!shid->hid) > + schedule_work(&shid->create_device_work); > + else > + schedule_work(&shid->refresh_device_work); > + > + break; > + case SPI_HID_INPUT_REPORT_TYPE_SET_OUTPUT_REPORT_RESP: > + if (shid->desc.no_output_report_ack) { > + dev_err(dev, "Unexpected output report response\n"); > + break; > + } > + fallthrough; > + case SPI_HID_INPUT_REPORT_TYPE_GET_FEATURE_RESP: > + case SPI_HID_INPUT_REPORT_TYPE_SET_FEATURE_RESP: > + if (!shid->ready) { > + dev_err(dev, > + "Unexpected response report while not ready: 0x%x\n", > + body.report_type); > + break; > + } > + fallthrough; > + case SPI_HID_INPUT_REPORT_TYPE_REPORT_DESC: > + spi_hid_response_handler(shid, buf); > + break; > + /* > + * FIXME: sending GET_INPUT and COMMAND reports not supported, thus > + * throw away responses to those, they should never come. > + */ > + case SPI_HID_INPUT_REPORT_TYPE_GET_INPUT_REPORT_RESP: > + case SPI_HID_INPUT_REPORT_TYPE_COMMAND_RESP: > + dev_err(dev, "Not a supported report type: 0x%x\n", > + body.report_type); > + break; > + default: > + dev_err(dev, "Unknown input report: 0x%x\n", > + body.report_type); > + schedule_work(&shid->error_work); > + break; > + } > +} > + > +static int spi_hid_bus_validate_header(struct spi_hid *shid, > + struct spi_hid_input_header *header) > +{ > + struct device *dev = &shid->spi->dev; > + > + if (header->version != SPI_HID_INPUT_HEADER_VERSION) { > + dev_err(dev, "Unknown input report version (v 0x%x)\n", > + header->version); > + return -EINVAL; > + } > + > + if (shid->desc.max_input_length != 0 && > + header->report_length > shid->desc.max_input_length) { > + dev_err(dev, "Input report body size %u > max expected of %u\n", > + header->report_length, > + shid->desc.max_input_length); > + return -EMSGSIZE; > + } > + > + if (header->last_fragment_flag != 1) { > + dev_err(dev, "Multi-fragment reports not supported\n"); > + return -EOPNOTSUPP; > + } > + > + if (header->sync_const != SPI_HID_INPUT_HEADER_SYNC_BYTE) { > + dev_err(dev, "Invalid input report sync constant (0x%x)\n", > + header->sync_const); > + return -EINVAL; > + } > + > + return 0; > +} > + > +static int spi_hid_create_device(struct spi_hid *shid) > +{ > + struct hid_device *hid; > + struct device *dev = &shid->spi->dev; > + int ret; > + > + hid = hid_allocate_device(); > + > + if (IS_ERR(hid)) { > + dev_err(dev, "Failed to allocate hid device: %ld\n", > + PTR_ERR(hid)); > + ret = PTR_ERR(hid); > + return ret; > + } > + > + hid->driver_data = shid->spi; > + hid->ll_driver = &spi_hid_ll_driver; > + hid->dev.parent = &shid->spi->dev; > + hid->bus = BUS_SPI; > + hid->version = shid->desc.hid_version; > + hid->vendor = shid->desc.vendor_id; > + hid->product = shid->desc.product_id; > + > + snprintf(hid->name, sizeof(hid->name), "spi %04hX:%04hX", > + hid->vendor, hid->product); > + strscpy(hid->phys, dev_name(&shid->spi->dev), sizeof(hid->phys)); > + > + shid->hid = hid; > + > + ret = hid_add_device(hid); > + if (ret) { > + dev_err(dev, "Failed to add hid device: %d\n", ret); > + /* > + * We likely got here because report descriptor request timed > + * out. Let's disconnect and destroy the hid_device structure. > + */ > + hid = spi_hid_disconnect_hid(shid); > + if (hid) > + hid_destroy_device(hid); > + return ret; > + } > + > + return 0; > +} > + > +static void spi_hid_create_device_work(struct work_struct *work) > +{ > + struct spi_hid *shid = > + container_of(work, struct spi_hid, create_device_work); > + struct device *dev = &shid->spi->dev; > + u8 prev_state = shid->power_state; > + int ret; > + > + trace_spi_hid_create_device_work(shid); > + > + ret = spi_hid_create_device(shid); > + if (ret) { > + dev_err(dev, "Failed to create hid device\n"); > + return; > + } > + > + spi_hid_suspend(shid); > + > + shid->attempts = 0; > + > + dev_dbg(dev, "%s: %s -> %s\n", __func__, > + spi_hid_power_mode_string(prev_state), > + spi_hid_power_mode_string(shid->power_state)); > +} > + > +static void spi_hid_refresh_device_work(struct work_struct *work) > +{ > + struct spi_hid *shid = > + container_of(work, struct spi_hid, refresh_device_work); > + struct device *dev = &shid->spi->dev; > + struct hid_device *hid; > + int ret; > + u32 new_crc32; > + > + trace_spi_hid_refresh_device_work(shid); > + > + mutex_lock(&shid->lock); > + ret = spi_hid_report_descriptor_request(shid); > + mutex_unlock(&shid->lock); > + if (ret < 0) { > + dev_err(dev, > + "Refresh: failed report descriptor request, error %d", > + ret); > + return; > + } > + > + new_crc32 = crc32_le(0, (unsigned char const *)shid->response.content, > + (size_t)ret); > + if (new_crc32 == shid->report_descriptor_crc32) { > + shid->ready = true; > + sysfs_notify(&dev->kobj, NULL, "ready"); > + return; > + } > + > + shid->report_descriptor_crc32 = new_crc32; > + shid->refresh_in_progress = true; > + > + hid = spi_hid_disconnect_hid(shid); > + if (hid) > + hid_destroy_device(hid); > + > + ret = spi_hid_create_device(shid); > + if (ret) > + dev_err(dev, "Failed to create hid device\n"); > + > + shid->refresh_in_progress = false; > + shid->ready = true; > + sysfs_notify(&dev->kobj, NULL, "ready"); > +} > + > +static void spi_hid_input_header_complete(void *_shid); > + > +static void spi_hid_input_body_complete(void *_shid) > +{ > + struct spi_hid *shid = _shid; > + struct device *dev = &shid->spi->dev; > + unsigned long flags; > + int ret; > + > + spin_lock_irqsave(&shid->input_lock, flags); > + > + if (shid->power_state == SPI_HID_POWER_MODE_OFF) { > + dev_warn(dev, > + "input body complete called while device is off\n"); > + goto out; > + } > + > + trace_spi_hid_input_body_complete(shid, > + shid->input_transfer[0].tx_buf, > + shid->input_transfer[0].len, > + shid->input_transfer[1].rx_buf, > + shid->input_transfer[1].len, > + shid->input_message.status); > + > + if (shid->input_message.status < 0) { > + dev_warn(dev, "error reading body, resetting %d\n", > + shid->input_message.status); > + shid->bus_error_count++; > + shid->bus_last_error = shid->input_message.status; > + schedule_work(&shid->error_work); > + goto out; > + } > + > + spi_hid_process_input_report(shid, &shid->input); > + > + if (--shid->input_transfer_pending) { > + struct spi_hid_input_buf *buf = &shid->input; > + > + trace_spi_hid_header_transfer(shid); > + ret = spi_hid_input_async(shid, buf->header, > + sizeof(buf->header), > + spi_hid_input_header_complete, true); > + if (ret) > + dev_err(dev, "failed to start header transfer %d\n", > + ret); > + } > + > +out: > + spin_unlock_irqrestore(&shid->input_lock, flags); > +} > + > +static void spi_hid_input_header_complete(void *_shid) > +{ > + struct spi_hid *shid = _shid; > + struct device *dev = &shid->spi->dev; > + struct spi_hid_input_header header; > + unsigned long flags; > + int ret = 0; > + > + spin_lock_irqsave(&shid->input_lock, flags); > + > + if (shid->power_state == SPI_HID_POWER_MODE_OFF) { > + dev_warn(dev, > + "input header complete called while device is off\n"); > + goto out; > + } > + > + trace_spi_hid_input_header_complete(shid, > + shid->input_transfer[0].tx_buf, > + shid->input_transfer[0].len, > + shid->input_transfer[1].rx_buf, > + shid->input_transfer[1].len, > + shid->input_message.status); > + > + if (shid->input_message.status < 0) { > + dev_warn(dev, "error reading header, resetting, error %d\n", > + shid->input_message.status); > + shid->bus_error_count++; > + shid->bus_last_error = shid->input_message.status; > + schedule_work(&shid->error_work); > + goto out; > + } > + spi_hid_populate_input_header(shid->input.header, &header); > + > + ret = spi_hid_bus_validate_header(shid, &header); > + if (ret) { > + dev_err(dev, "failed to validate header: %d\n", ret); > + print_hex_dump(KERN_ERR, "spi_hid: header buffer: ", > + DUMP_PREFIX_NONE, 16, 1, > + shid->input.header, > + sizeof(shid->input.header), > + false); > + shid->bus_error_count++; > + shid->bus_last_error = ret; > + goto out; > + } > + > + ret = spi_hid_input_async(shid, shid->input.body, header.report_length, > + spi_hid_input_body_complete, false); > + if (ret) > + dev_err(dev, "failed body async transfer: %d\n", ret); > + > +out: > + if (ret) > + shid->input_transfer_pending = 0; > + > + spin_unlock_irqrestore(&shid->input_lock, flags); > +} > + > +static int spi_hid_get_request(struct spi_hid *shid, u8 content_id) > +{ > + int ret; > + struct device *dev = &shid->spi->dev; > + struct spi_hid_output_report report = { > + .report_type = SPI_HID_OUTPUT_REPORT_TYPE_HID_GET_FEATURE, > + .content_length = 0, > + .content_id = content_id, > + .content = NULL, > + }; > + > + ret = spi_hid_sync_request(shid, &report); > + if (ret) { > + dev_err(dev, > + "Expected get request response not received! Error %d\n", > + ret); > + schedule_work(&shid->error_work); > + } > + > + return ret; > +} > + > +static int spi_hid_set_request(struct spi_hid *shid, > + u8 *arg_buf, u16 arg_len, u8 content_id) > +{ > + struct spi_hid_output_report report = { > + .report_type = SPI_HID_OUTPUT_REPORT_TYPE_HID_SET_FEATURE, > + .content_length = arg_len, > + .content_id = content_id, > + .content = arg_buf, > + }; > + > + return spi_hid_sync_request(shid, &report); > +} > + > +static irqreturn_t spi_hid_dev_irq(int irq, void *_shid) > +{ > + struct spi_hid *shid = _shid; > + struct device *dev = &shid->spi->dev; > + int ret = 0; > + > + spin_lock(&shid->input_lock); > + trace_spi_hid_dev_irq(shid, irq); > + > + if (shid->input_transfer_pending++) > + goto out; > + > + trace_spi_hid_header_transfer(shid); > + ret = spi_hid_input_async(shid, shid->input.header, > + sizeof(shid->input.header), > + spi_hid_input_header_complete, true); > + if (ret) > + dev_err(dev, "Failed to start header transfer: %d\n", ret); > + > +out: > + spin_unlock(&shid->input_lock); > + > + return IRQ_HANDLED; > +} > + > +/* hid_ll_driver interface functions */ > + > +static int spi_hid_ll_start(struct hid_device *hid) > +{ > + struct spi_device *spi = hid->driver_data; > + struct spi_hid *shid = spi_get_drvdata(spi); > + > + if (shid->desc.max_input_length < HID_MIN_BUFFER_SIZE) { > + dev_err(&shid->spi->dev, > + "HID_MIN_BUFFER_SIZE > max_input_length (%d)\n", > + shid->desc.max_input_length); > + return -EINVAL; > + } > + > + return 0; > +} > + > +static void spi_hid_ll_stop(struct hid_device *hid) > +{ > + hid->claimed = 0; > +} > + > +static int spi_hid_ll_open(struct hid_device *hid) > +{ > + struct spi_device *spi = hid->driver_data; > + struct spi_hid *shid = spi_get_drvdata(spi); > + struct device *dev = &spi->dev; > + u8 prev_state = shid->power_state; > + > + if (shid->refresh_in_progress) > + return 0; > + > + spi_hid_resume(shid); > + > + dev_dbg(dev, "%s: %s -> %s\n", __func__, > + spi_hid_power_mode_string(prev_state), > + spi_hid_power_mode_string(shid->power_state)); > + > + return 0; > +} > + > +static void spi_hid_ll_close(struct hid_device *hid) > +{ > + struct spi_device *spi = hid->driver_data; > + struct spi_hid *shid = spi_get_drvdata(spi); > + struct device *dev = &spi->dev; > + u8 prev_state = shid->power_state; > + > + if (shid->refresh_in_progress) > + return; > + > + spi_hid_suspend(shid); > + > + shid->attempts = 0; > + > + dev_dbg(dev, "%s: %s -> %s\n", __func__, > + spi_hid_power_mode_string(prev_state), > + spi_hid_power_mode_string(shid->power_state)); > +} > + > +static int spi_hid_ll_power(struct hid_device *hid, int level) > +{ > + struct spi_device *spi = hid->driver_data; > + struct spi_hid *shid = spi_get_drvdata(spi); > + int ret = 0; > + > + mutex_lock(&shid->lock); > + if (!shid->hid) > + ret = -ENODEV; > + mutex_unlock(&shid->lock); > + > + return ret; > +} > + > +static int spi_hid_ll_parse(struct hid_device *hid) > +{ > + struct spi_device *spi = hid->driver_data; > + struct spi_hid *shid = spi_get_drvdata(spi); > + struct device *dev = &spi->dev; > + int ret, len; > + > + mutex_lock(&shid->lock); > + > + len = spi_hid_report_descriptor_request(shid); > + if (len < 0) { > + dev_err(dev, "Report descriptor request failed, %d\n", len); > + ret = len; > + goto out; > + } > + > + /* > + * FIXME: below call returning 0 doesn't mean that the report descriptor > + * is good. We might be caching a crc32 of a corrupted r. d. or who > + * knows what the FW sent. Need to have a feedback loop about r. d. > + * being ok and only then cache it. > + */ > + ret = hid_parse_report(hid, (__u8 *)shid->response.content, len); > + if (ret) > + dev_err(dev, "failed parsing report: %d\n", ret); > + else > + shid->report_descriptor_crc32 = crc32_le(0, > + (unsigned char const *)shid->response.content, > + len); > + > +out: > + mutex_unlock(&shid->lock); > + > + return ret; > +} > + > +static int spi_hid_ll_raw_request(struct hid_device *hid, > + unsigned char reportnum, __u8 *buf, size_t len, > + unsigned char rtype, int reqtype) > +{ > + struct spi_device *spi = hid->driver_data; > + struct spi_hid *shid = spi_get_drvdata(spi); > + struct device *dev = &spi->dev; > + int ret; > + > + if (!shid->ready) { > + dev_err(&shid->spi->dev, "%s called in unready state\n", > + __func__); > + return -ENODEV; This will confuse users for no good reason. Do not let them call into the driver until it is ready. > + } > + > + mutex_lock(&shid->lock); > + > + switch (reqtype) { > + case HID_REQ_SET_REPORT: > + if (buf[0] != reportnum) { > + dev_err(dev, "report id mismatch\n"); > + ret = -EINVAL; > + break; > + } > + > + ret = spi_hid_set_request(shid, &buf[1], len - 1, > + reportnum); > + if (ret) { > + dev_err(dev, "failed to set report\n"); > + break; > + } > + > + ret = len; > + break; > + case HID_REQ_GET_REPORT: > + ret = spi_hid_get_request(shid, reportnum); > + if (ret) { > + dev_err(dev, "failed to get report\n"); > + break; > + } > + > + ret = min_t(size_t, len, > + shid->response.body[1] | (shid->response.body[2] << 8)); > + memcpy(buf, &shid->response.content, ret); > + break; > + default: > + dev_err(dev, "invalid request type\n"); > + ret = -EIO; > + } > + > + mutex_unlock(&shid->lock); > + > + return ret; > +} > + > +static int spi_hid_ll_output_report(struct hid_device *hid, > + __u8 *buf, size_t len) > +{ > + int ret; > + struct spi_device *spi = hid->driver_data; > + struct spi_hid *shid = spi_get_drvdata(spi); > + struct device *dev = &spi->dev; > + struct spi_hid_output_report report = { > + .report_type = SPI_HID_OUTPUT_REPORT_TYPE_HID_OUTPUT_REPORT, > + .content_length = len - 1, > + .content_id = buf[0], > + .content = &buf[1], > + }; > + > + mutex_lock(&shid->lock); > + if (!shid->ready) { > + dev_err(dev, "%s called in unready state\n", __func__); > + ret = -ENODEV; > + goto out; > + } > + > + if (shid->desc.no_output_report_ack) > + ret = spi_hid_send_output_report(shid, &report); > + else > + ret = spi_hid_sync_request(shid, &report); > + > + if (ret) > + dev_err(dev, "failed to send output report\n"); > + > +out: > + mutex_unlock(&shid->lock); > + > + if (ret > 0) > + return -ret; > + > + if (ret < 0) > + return ret; > + > + return len; > +} > + > +static struct hid_ll_driver spi_hid_ll_driver = { > + .start = spi_hid_ll_start, > + .stop = spi_hid_ll_stop, > + .open = spi_hid_ll_open, > + .close = spi_hid_ll_close, > + .power = spi_hid_ll_power, > + .parse = spi_hid_ll_parse, > + .output_report = spi_hid_ll_output_report, > + .raw_request = spi_hid_ll_raw_request, > +}; > + > +static ssize_t ready_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct spi_hid *shid = dev_get_drvdata(dev); > + > + return snprintf(buf, PAGE_SIZE, "%s\n", > + shid->ready ? "ready" : "not ready"); Why is this needed? Why can't we simply delay registering HID device until after we are ready to handle it? Or delay in open? > +} > +static DEVICE_ATTR_RO(ready); > + > +static ssize_t bus_error_count_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct spi_hid *shid = dev_get_drvdata(dev); > + > + return snprintf(buf, PAGE_SIZE, "%d (%d)\n", > + shid->bus_error_count, shid->bus_last_error); This and below I think better suited for debugfs. > +} > +static DEVICE_ATTR_RO(bus_error_count); > + > +static ssize_t regulator_error_count_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct spi_hid *shid = dev_get_drvdata(dev); > + > + return snprintf(buf, PAGE_SIZE, "%d (%d)\n", > + shid->regulator_error_count, > + shid->regulator_last_error); > +} > +static DEVICE_ATTR_RO(regulator_error_count); > + > +static ssize_t device_initiated_reset_count_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct spi_hid *shid = dev_get_drvdata(dev); > + > + return snprintf(buf, PAGE_SIZE, "%d\n", shid->dir_count); > +} > +static DEVICE_ATTR_RO(device_initiated_reset_count); > + > +static const struct attribute *const spi_hid_attributes[] = { > + &dev_attr_ready.attr, > + &dev_attr_bus_error_count.attr, > + &dev_attr_regulator_error_count.attr, > + &dev_attr_device_initiated_reset_count.attr, > + NULL /* Terminator */ > +}; > + > +static int spi_hid_probe(struct spi_device *spi) > +{ > + struct device *dev = &spi->dev; > + struct spi_hid *shid; > + unsigned long irqflags; > + int ret; > + > + if (spi->irq <= 0) { > + dev_err(dev, "Missing IRQ\n"); > + ret = spi->irq ?: -EINVAL; > + goto err0; > + } > + > + shid = devm_kzalloc(dev, sizeof(struct spi_hid), GFP_KERNEL); > + if (!shid) { > + ret = -ENOMEM; > + goto err0; > + } > + > + shid->spi = spi; > + shid->power_state = SPI_HID_POWER_MODE_ON; > + spi_set_drvdata(spi, shid); > + > + ret = sysfs_create_files(&dev->kobj, spi_hid_attributes); I'd recommend using devm* for all resources used by this driver. > + if (ret) { > + dev_err(dev, "Unable to create sysfs attributes\n"); > + goto err0; > + } > + > + ret = spi_hid_of_populate_config(&shid->conf, dev); Error handling? > + > + /* Using now populated conf let's pre-calculate the read approvals */ > + spi_hid_populate_read_approvals(&shid->conf, shid->read_approval_header, > + shid->read_approval_body); > + > + mutex_init(&shid->lock); > + init_completion(&shid->output_done); > + > + spin_lock_init(&shid->input_lock); > + INIT_WORK(&shid->reset_work, spi_hid_reset_work); > + INIT_WORK(&shid->create_device_work, spi_hid_create_device_work); > + INIT_WORK(&shid->refresh_device_work, spi_hid_refresh_device_work); > + INIT_WORK(&shid->error_work, spi_hid_error_work); > + > + /* > + * At the end of probe we initialize the device: > + * 0) Default pinctrl in DT: assert reset, bias the interrupt line > + * 1) sleep minimal reset delay > + * 2) request IRQ > + * 3) power up the device > + * 4) sleep 5ms > + * 5) deassert reset (high) > + * 6) sleep 5ms > + */ > + > + spi_hid_of_sleep_minimal_reset_delay(&shid->conf); > + > + irqflags = irq_get_trigger_type(spi->irq) | IRQF_ONESHOT; Specifying ONESHOT mode for non-threaded IRQ does not make much sense. Why don't you use threaded IRQ and get rid of your async/work hanlding? > + ret = request_irq(spi->irq, spi_hid_dev_irq, irqflags, > + dev_name(&spi->dev), shid); > + if (ret) > + goto err1; > + > + ret = spi_hid_of_power_up(&shid->conf); > + if (ret) { > + dev_err(dev, "%s: could not power up\n", __func__); > + shid->regulator_error_count++; > + shid->regulator_last_error = ret; > + goto err1; > + } > + > + spi_hid_of_deassert_reset(&shid->conf); > + > + dev_err(dev, "%s: d3 -> %s\n", __func__, > + spi_hid_power_mode_string(shid->power_state)); > + > + return 0; > + > +err1: > + sysfs_remove_files(&dev->kobj, spi_hid_attributes); > + > +err0: > + return ret; > +} > + > +static int spi_hid_remove(struct spi_device *spi) > +{ > + struct spi_hid *shid = spi_get_drvdata(spi); > + struct device *dev = &spi->dev; > + int ret; > + > + spi_hid_of_assert_reset(&shid->conf); > + ret = spi_hid_of_power_down(&shid->conf); > + if (ret) { > + dev_err(dev, "failed to disable regulator\n"); > + shid->regulator_error_count++; > + shid->regulator_last_error = ret; > + } > + free_irq(spi->irq, shid); > + sysfs_remove_files(&dev->kobj, spi_hid_attributes); > + spi_hid_stop_hid(shid); > + > + return 0; > +} > + > +static const struct spi_device_id spi_hid_id_table[] = { > + { "hid", 0 }, > + { "hid-over-spi", 0 }, > + { }, > +}; > +MODULE_DEVICE_TABLE(spi, spi_hid_id_table); > + > +static struct spi_driver spi_hid_driver = { > + .driver = { > + .name = "spi_hid", > + .owner = THIS_MODULE, > + .of_match_table = of_match_ptr(spi_hid_of_match), > + .probe_type = PROBE_PREFER_ASYNCHRONOUS, > + }, > + .probe = spi_hid_probe, > + .remove = spi_hid_remove, > + .id_table = spi_hid_id_table, > +}; > + > +module_spi_driver(spi_hid_driver); > + > +MODULE_DESCRIPTION("HID over SPI transport driver"); > +MODULE_AUTHOR("Dmitry Antipov <dmanti@xxxxxxxxxxxxx>"); > +MODULE_LICENSE("GPL"); > diff --git a/drivers/hid/spi-hid/spi-hid-core.h b/drivers/hid/spi-hid/spi-hid-core.h > new file mode 100644 > index 000000000000..95e667ad53ec > --- /dev/null > +++ b/drivers/hid/spi-hid/spi-hid-core.h > @@ -0,0 +1,188 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * spi-hid-core.h > + * > + * Copyright (c) 2021 Microsoft Corporation > + */ > + > +#ifndef SPI_HID_CORE_H > +#define SPI_HID_CORE_H > + > +#include <linux/completion.h> > +#include <linux/kernel.h> > +#include <linux/spi/spi.h> > +#include <linux/spinlock.h> > +#include <linux/types.h> > + > +#include "spi-hid-of.h" > + > +/* Protocol constants */ > +#define SPI_HID_READ_APPROVAL_CONSTANT 0xff > +#define SPI_HID_INPUT_HEADER_SYNC_BYTE 0x5a > +#define SPI_HID_INPUT_HEADER_VERSION 0x03 > +#define SPI_HID_SUPPORTED_VERSION 0x0300 > + > +/* Protocol message size constants */ > +#define SPI_HID_READ_APPROVAL_LEN 5 > +#define SPI_HID_INPUT_HEADER_LEN 4 > +#define SPI_HID_INPUT_BODY_LEN 4 > +#define SPI_HID_OUTPUT_HEADER_LEN 8 > +#define SPI_HID_DEVICE_DESCRIPTOR_LENGTH 24 > + > +/* Protocol message type constants */ > +#define SPI_HID_INPUT_REPORT_TYPE_DATA 0x01 > +#define SPI_HID_INPUT_REPORT_TYPE_RESET_RESP 0x03 > +#define SPI_HID_INPUT_REPORT_TYPE_COMMAND_RESP 0x04 > +#define SPI_HID_INPUT_REPORT_TYPE_GET_FEATURE_RESP 0x05 > +#define SPI_HID_INPUT_REPORT_TYPE_DEVICE_DESC 0x07 > +#define SPI_HID_INPUT_REPORT_TYPE_REPORT_DESC 0x08 > +#define SPI_HID_INPUT_REPORT_TYPE_SET_FEATURE_RESP 0x09 > +#define SPI_HID_INPUT_REPORT_TYPE_SET_OUTPUT_REPORT_RESP 0x0a > +#define SPI_HID_INPUT_REPORT_TYPE_GET_INPUT_REPORT_RESP 0x0b > + > +#define SPI_HID_OUTPUT_REPORT_TYPE_DEVICE_DESC_REQUEST 0x01 > +#define SPI_HID_OUTPUT_REPORT_TYPE_REPORT_DESC_REQUEST 0x02 > +#define SPI_HID_OUTPUT_REPORT_TYPE_HID_SET_FEATURE 0x03 > +#define SPI_HID_OUTPUT_REPORT_TYPE_HID_GET_FEATURE 0x04 > +#define SPI_HID_OUTPUT_REPORT_TYPE_HID_OUTPUT_REPORT 0x05 > +#define SPI_HID_OUTPUT_REPORT_TYPE_INPUT_REPORT_REQUEST 0x06 > +#define SPI_HID_OUTPUT_REPORT_TYPE_COMMAND 0x07 > + > +#define SPI_HID_OUTPUT_REPORT_CONTENT_ID_DESC_REQUEST 0x00 > + > +/* Power mode constants */ > +#define SPI_HID_POWER_MODE_ON 0x01 > +#define SPI_HID_POWER_MODE_SLEEP 0x02 > +#define SPI_HID_POWER_MODE_OFF 0x03 > +#define SPI_HID_POWER_MODE_WAKING_SLEEP 0x04 > + > +/* Raw input buffer with data from the bus */ > +struct spi_hid_input_buf { > + __u8 header[SPI_HID_INPUT_HEADER_LEN]; > + __u8 body[SPI_HID_INPUT_BODY_LEN]; > + u8 content[SZ_8K]; > +}; > + > +/* Processed data from input report header */ > +struct spi_hid_input_header { > + u8 version; > + u16 report_length; > + u8 last_fragment_flag; > + u8 sync_const; > +}; > + > +/* Processed data from input report body, excluding the content */ > +struct spi_hid_input_body { > + u8 report_type; > + u16 content_length; > + u8 content_id; > +}; > + > +/* Processed data from an input report */ > +struct spi_hid_input_report { > + u8 report_type; > + u16 content_length; > + u8 content_id; > + u8 *content; > +}; > + > +/* Raw output report buffer to be put on the bus */ > +struct spi_hid_output_buf { > + __u8 header[SPI_HID_OUTPUT_HEADER_LEN]; > + u8 content[SZ_8K]; > +}; > + > +/* Data necessary to send an output report */ > +struct spi_hid_output_report { > + u8 report_type; > + u16 content_length; > + u8 content_id; > + u8 *content; > +}; > + > +/* Raw content in device descriptor */ > +struct spi_hid_device_desc_raw { > + __le16 wDeviceDescLength; > + __le16 bcdVersion; > + __le16 wReportDescLength; > + __le16 wMaxInputLength; > + __le16 wMaxOutputLength; > + __le16 wMaxFragmentLength; > + __le16 wVendorID; > + __le16 wProductID; > + __le16 wVersionID; > + __le16 wFlags; > + __u8 reserved[4]; > +} __packed; > + > +/* Processed data from a device descriptor */ > +struct spi_hid_device_descriptor { > + u16 hid_version; > + u16 report_descriptor_length; > + u16 max_input_length; > + u16 max_output_length; > + u16 max_fragment_length; > + u16 vendor_id; > + u16 product_id; > + u16 version_id; > + u8 no_output_report_ack; bool? > +}; > + > +/* Driver context */ > +struct spi_hid { > + struct spi_device *spi; > + struct hid_device *hid; > + > + struct spi_transfer input_transfer[2]; > + struct spi_transfer output_transfer; > + struct spi_message input_message; > + struct spi_message output_message; > + > + struct spi_hid_of_config conf; > + struct spi_hid_device_descriptor desc; > + struct spi_hid_output_buf output; > + struct spi_hid_input_buf input; > + struct spi_hid_input_buf response; > + > + spinlock_t input_lock; > + > + u32 input_transfer_pending; > + > + u8 power_state; > + > + u8 attempts; > + > + /* > + * ready flag indicates that the FW is ready to accept commands and > + * requests. The FW becomes ready after sending the report descriptor. > + */ > + bool ready; > + /* > + * refresh_in_progress is set to true while the refresh_device worker > + * thread is destroying and recreating the hidraw device. When this flag > + * is set to true, the ll_close and ll_open functions will not cause > + * power state changes. > + */ > + bool refresh_in_progress; > + > + struct work_struct reset_work; > + struct work_struct create_device_work; > + struct work_struct refresh_device_work; > + struct work_struct error_work; > + > + struct mutex lock; > + struct completion output_done; > + > + __u8 read_approval_header[SPI_HID_READ_APPROVAL_LEN]; > + __u8 read_approval_body[SPI_HID_READ_APPROVAL_LEN]; > + > + u32 report_descriptor_crc32; > + > + u32 regulator_error_count; > + int regulator_last_error; > + u32 bus_error_count; > + int bus_last_error; > + u32 dir_count; > +}; > + > +#endif > diff --git a/drivers/hid/spi-hid/spi-hid-of.c b/drivers/hid/spi-hid/spi-hid-of.c > new file mode 100755 > index 000000000000..4896a90c2e8e > --- /dev/null > +++ b/drivers/hid/spi-hid/spi-hid-of.c > @@ -0,0 +1,148 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * HID over SPI protocol, Open Firmware related code > + * spi-hid-of.c > + * > + * Copyright (c) 2021 Microsoft Corporation > + * > + * This code was forked out of the HID over SPI core code, which is partially > + * based on "HID over I2C protocol implementation: > + * > + * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@xxxxxxxxx> > + * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France > + * Copyright (c) 2012 Red Hat, Inc > + * > + * which in turn is partially based on "USB HID support for Linux": > + * > + * Copyright (c) 1999 Andreas Gal > + * Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@xxxxxxx> > + * Copyright (c) 2005 Michael Haboustak <mike-@xxxxxxxxxxxx> for Concept2, Inc > + * Copyright (c) 2007-2008 Oliver Neukum > + * Copyright (c) 2006-2010 Jiri Kosina > + */ > +#include <linux/of.h> > +#include <linux/regulator/consumer.h> > +#include <linux/gpio/consumer.h> > +#include <linux/delay.h> > + > +#include "spi-hid-core.h" > + > +const struct of_device_id spi_hid_of_match[] = { > + { .compatible = "hid-over-spi" }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, spi_hid_of_match); > + > +int spi_hid_of_populate_config(struct spi_hid_of_config *conf, > + struct device *dev) > +{ > + int ret; > + u32 val; > + > + ret = device_property_read_u32(dev, "input-report-header-address", > + &val); > + if (ret) { > + dev_err(dev, "Input report header address not provided\n"); > + return -ENODEV; > + } > + conf->input_report_header_address = val; > + > + ret = device_property_read_u32(dev, "input-report-body-address", &val); > + if (ret) { > + dev_err(dev, "Input report body address not provided\n"); > + return -ENODEV; > + } > + conf->input_report_body_address = val; > + > + ret = device_property_read_u32(dev, "output-report-address", &val); > + if (ret) { > + dev_err(dev, "Output report address not provided\n"); > + return -ENODEV; > + } > + conf->output_report_address = val; > + > + ret = device_property_read_u32(dev, "read-opcode", &val); > + if (ret) { > + dev_err(dev, "Read opcode not provided\n"); > + return -ENODEV; > + } > + conf->read_opcode = val; > + > + ret = device_property_read_u32(dev, "write-opcode", &val); > + if (ret) { > + dev_err(dev, "Write opcode not provided\n"); > + return -ENODEV; > + } > + conf->write_opcode = val; > + > + ret = device_property_read_u32(dev, "post-power-on-delay-ms", &val); > + if (ret) { > + dev_err(dev, "Post-power-on delay not provided\n"); > + return -ENODEV; > + } > + conf->post_power_on_delay_ms = val; > + > + ret = device_property_read_u32(dev, "minimal-reset-delay-ms", &val); > + if (ret) { > + dev_err(dev, "Minimal reset time not provided\n"); > + return -ENODEV; > + } > + conf->minimal_reset_delay_ms = val; > + > + /* FIXME: not reading flags from DT, multi-SPI modes not supported */ > + > + conf->supply = devm_regulator_get(dev, "vdd"); > + if (IS_ERR(conf->supply)) { > + if (PTR_ERR(conf->supply) != -EPROBE_DEFER) > + dev_err(dev, "Failed to get regulator: %ld\n", > + PTR_ERR(conf->supply)); > + return PTR_ERR(conf->supply); > + } > + > + conf->reset_gpio = devm_gpiod_get(dev, "reset-gpio", GPIOD_OUT_LOW); > + if (IS_ERR(conf->reset_gpio)) { > + dev_err(dev, "%s: error getting GPIO\n", __func__); > + return PTR_ERR(conf->reset_gpio); > + } > + > + return 0; > +} > + > +int spi_hid_of_power_down(struct spi_hid_of_config *conf) > +{ > + if (regulator_is_enabled(conf->supply) == 0) > + return 0; > + > + return regulator_disable(conf->supply); > +} > + > +int spi_hid_of_power_up(struct spi_hid_of_config *conf) > +{ > + int ret; > + > + if (regulator_is_enabled(conf->supply) > 0) > + return 0; > + > + ret = regulator_enable(conf->supply); > + > + usleep_range(1000 * conf->post_power_on_delay_ms, > + 1000 * (conf->post_power_on_delay_ms + 1)); > + > + return ret; > +} > + > +void spi_hid_of_assert_reset(struct spi_hid_of_config *conf) > +{ > + gpiod_set_value(conf->reset_gpio, 1); > +} > + > +void spi_hid_of_deassert_reset(struct spi_hid_of_config *conf) > +{ > + gpiod_set_value(conf->reset_gpio, 0); Why do we need these wrappers? > +} > + > +void spi_hid_of_sleep_minimal_reset_delay(struct spi_hid_of_config *conf) > +{ > + usleep_range(1000 * conf->minimal_reset_delay_ms, > + 1000 * (conf->minimal_reset_delay_ms + 1)); > +} > \ No newline at end of file > diff --git a/drivers/hid/spi-hid/spi-hid-of.h b/drivers/hid/spi-hid/spi-hid-of.h > new file mode 100755 > index 000000000000..5991011d8921 > --- /dev/null > +++ b/drivers/hid/spi-hid/spi-hid-of.h > @@ -0,0 +1,34 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * spi-hid-of.h > + * > + * Copyright (c) 2021 Microsoft Corporation > + */ > + > +#ifndef SPI_HID_OF_H > +#define SPI_HID_OF_H > + > +extern const struct of_device_id spi_hid_of_match[]; > + > +/* Config structure is filled with data from Device Tree */ > +struct spi_hid_of_config { > + u32 input_report_header_address; > + u32 input_report_body_address; > + u32 output_report_address; > + u8 read_opcode; > + u8 write_opcode; > + u32 post_power_on_delay_ms; > + u32 minimal_reset_delay_ms; > + struct gpio_desc *reset_gpio; > + struct regulator *supply; > +}; > + > +int spi_hid_of_populate_config(struct spi_hid_of_config *conf, > + struct device *dev); > +int spi_hid_of_power_down(struct spi_hid_of_config *conf); > +int spi_hid_of_power_up(struct spi_hid_of_config *conf); > +void spi_hid_of_assert_reset(struct spi_hid_of_config *conf); > +void spi_hid_of_deassert_reset(struct spi_hid_of_config *conf); > +void spi_hid_of_sleep_minimal_reset_delay(struct spi_hid_of_config *conf); > + > +#endif > diff --git a/drivers/hid/spi-hid/spi-hid_trace.h b/drivers/hid/spi-hid/spi-hid_trace.h > new file mode 100644 > index 000000000000..905de02d85aa > --- /dev/null > +++ b/drivers/hid/spi-hid/spi-hid_trace.h > @@ -0,0 +1,198 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * spi-hid_trace.h > + * > + * Copyright (c) 2021 Microsoft Corporation > + */ > + > +#undef TRACE_SYSTEM > +#define TRACE_SYSTEM spi_hid > + > +#if !defined(_SPI_HID_TRACE_H) || defined(TRACE_HEADER_MULTI_READ) > +#define _SPI_HID_TRACE_H > + > +#include <linux/types.h> > +#include <linux/tracepoint.h> > +#include "spi-hid-core.h" > + > +DECLARE_EVENT_CLASS(spi_hid_transfer, > + TP_PROTO(struct spi_hid *shid, const void *tx_buf, int tx_len, > + const void *rx_buf, u16 rx_len, int ret), > + > + TP_ARGS(shid, tx_buf, tx_len, rx_buf, rx_len, ret), > + > + TP_STRUCT__entry( > + __field(int, bus_num) > + __field(int, chip_select) > + __field(int, len) > + __field(int, ret) > + __dynamic_array(u8, rx_buf, rx_len) > + __dynamic_array(u8, tx_buf, tx_len) > + ), > + > + TP_fast_assign( > + __entry->bus_num = shid->spi->controller->bus_num; > + __entry->chip_select = shid->spi->chip_select; > + __entry->len = rx_len + tx_len; > + __entry->ret = ret; > + > + memcpy(__get_dynamic_array(tx_buf), tx_buf, tx_len); > + memcpy(__get_dynamic_array(rx_buf), rx_buf, rx_len); > + ), > + > + TP_printk("spi%d.%d: len=%d tx=[%*phD] rx=[%*phD] --> %d", > + __entry->bus_num, __entry->chip_select, __entry->len, > + __get_dynamic_array_len(tx_buf), __get_dynamic_array(tx_buf), > + __get_dynamic_array_len(rx_buf), __get_dynamic_array(rx_buf), > + __entry->ret) > +); > + > +DEFINE_EVENT(spi_hid_transfer, spi_hid_input_async, > + TP_PROTO(struct spi_hid *shid, const void *tx_buf, int tx_len, > + const void *rx_buf, u16 rx_len, int ret), > + TP_ARGS(shid, tx_buf, tx_len, rx_buf, rx_len, ret) > +); > + > +DEFINE_EVENT(spi_hid_transfer, spi_hid_input_header_complete, > + TP_PROTO(struct spi_hid *shid, const void *tx_buf, int tx_len, > + const void *rx_buf, u16 rx_len, int ret), > + TP_ARGS(shid, tx_buf, tx_len, rx_buf, rx_len, ret) > +); > + > +DEFINE_EVENT(spi_hid_transfer, spi_hid_input_body_complete, > + TP_PROTO(struct spi_hid *shid, const void *tx_buf, int tx_len, > + const void *rx_buf, u16 rx_len, int ret), > + TP_ARGS(shid, tx_buf, tx_len, rx_buf, rx_len, ret) > +); > + > +DEFINE_EVENT(spi_hid_transfer, spi_hid_output_begin, > + TP_PROTO(struct spi_hid *shid, const void *tx_buf, int tx_len, > + const void *rx_buf, u16 rx_len, int ret), > + TP_ARGS(shid, tx_buf, tx_len, rx_buf, rx_len, ret) > +); > + > +DEFINE_EVENT(spi_hid_transfer, spi_hid_output_end, > + TP_PROTO(struct spi_hid *shid, const void *tx_buf, int tx_len, > + const void *rx_buf, u16 rx_len, int ret), > + TP_ARGS(shid, tx_buf, tx_len, rx_buf, rx_len, ret) > +); > + > +DECLARE_EVENT_CLASS(spi_hid_irq, > + TP_PROTO(struct spi_hid *shid, int irq), > + > + TP_ARGS(shid, irq), > + > + TP_STRUCT__entry( > + __field(int, bus_num) > + __field(int, chip_select) > + __field(int, irq) > + ), > + > + TP_fast_assign( > + __entry->bus_num = shid->spi->controller->bus_num; > + __entry->chip_select = shid->spi->chip_select; > + __entry->irq = irq; > + ), > + > + TP_printk("spi%d.%d: IRQ %d", > + __entry->bus_num, __entry->chip_select, __entry->irq) > +); > + > +DEFINE_EVENT(spi_hid_irq, spi_hid_dev_irq, > + TP_PROTO(struct spi_hid *shid, int irq), > + TP_ARGS(shid, irq) > +); > + > +DECLARE_EVENT_CLASS(spi_hid, > + TP_PROTO(struct spi_hid *shid), > + > + TP_ARGS(shid), > + > + TP_STRUCT__entry( > + __field(int, bus_num) > + __field(int, chip_select) > + __field(int, power_state) > + __field(u32, input_transfer_pending) > + __field(bool, ready) > + > + __field(int, vendor_id) > + __field(int, product_id) > + __field(int, max_input_length) > + __field(int, max_output_length) > + __field(u16, hid_version) > + __field(u16, report_descriptor_length) > + __field(u16, version_id) > + ), > + > + TP_fast_assign( > + __entry->bus_num = shid->spi->controller->bus_num; > + __entry->chip_select = shid->spi->chip_select; > + __entry->power_state = shid->power_state; > + __entry->input_transfer_pending = shid->input_transfer_pending; > + __entry->ready = shid->ready; > + > + __entry->vendor_id = shid->desc.vendor_id; > + __entry->product_id = shid->desc.product_id; > + __entry->max_input_length = shid->desc.max_input_length; > + __entry->max_output_length = shid->desc.max_output_length; > + __entry->hid_version = shid->desc.hid_version; > + __entry->report_descriptor_length = > + shid->desc.report_descriptor_length; > + __entry->version_id = shid->desc.version_id; > + ), > + > + TP_printk("spi%d.%d: (%04x:%04x v%d) HID v%d.%d state i:%d p:%d len i:%d o:%d r:%d flags %c:%d", > + __entry->bus_num, __entry->chip_select, __entry->vendor_id, > + __entry->product_id, __entry->version_id, > + __entry->hid_version >> 8, __entry->hid_version & 0xff, > + __entry->power_state, __entry->max_input_length, > + __entry->max_output_length, __entry->report_descriptor_length, > + __entry->ready ? 'R' : 'r', __entry->input_transfer_pending) > +); > + > +DEFINE_EVENT(spi_hid, spi_hid_header_transfer, > + TP_PROTO(struct spi_hid *shid), > + TP_ARGS(shid) > +); > + > +DEFINE_EVENT(spi_hid, spi_hid_process_input_report, > + TP_PROTO(struct spi_hid *shid), > + TP_ARGS(shid) > +); > + > +DEFINE_EVENT(spi_hid, spi_hid_input_report_handler, > + TP_PROTO(struct spi_hid *shid), > + TP_ARGS(shid) > +); > + > +DEFINE_EVENT(spi_hid, spi_hid_reset_work, > + TP_PROTO(struct spi_hid *shid), > + TP_ARGS(shid) > +); > + > +DEFINE_EVENT(spi_hid, spi_hid_create_device_work, > + TP_PROTO(struct spi_hid *shid), > + TP_ARGS(shid) > +); > + > +DEFINE_EVENT(spi_hid, spi_hid_refresh_device_work, > + TP_PROTO(struct spi_hid *shid), > + TP_ARGS(shid) > +); > + > +DEFINE_EVENT(spi_hid, spi_hid_response_handler, > + TP_PROTO(struct spi_hid *shid), > + TP_ARGS(shid) > +); > + > +DEFINE_EVENT(spi_hid, spi_hid_error_handler, > + TP_PROTO(struct spi_hid *shid), > + TP_ARGS(shid) > +); > + > +#endif /* _SPI_HID_TRACE_H */ > + > +#undef TRACE_INCLUDE_PATH > +#define TRACE_INCLUDE_PATH . > +#define TRACE_INCLUDE_FILE spi-hid_trace > +#include <trace/define_trace.h> > diff --git a/drivers/hid/spi-hid/trace.c b/drivers/hid/spi-hid/trace.c > new file mode 100644 > index 000000000000..aaa2da0c9642 > --- /dev/null > +++ b/drivers/hid/spi-hid/trace.c > @@ -0,0 +1,11 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/** > + * trace.c - SPI HID Trace Support > + * > + * Copyright (c) 2021 Microsoft Corporation > + * > + * Author: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxx> > + */ > + > +#define CREATE_TRACE_POINTS > +#include "spi-hid_trace.h" > -- > 2.25.1 > Thanks. -- Dmitry
