Add HID low level driver callbacks to register SPI as a HID driver, and an external touch device as a HID device.
Signed-off-by: Dmitry Antipov <[email protected]> Signed-off-by: Angela Czubak <[email protected]> Signed-off-by: Jingyuan Liang <[email protected]> --- drivers/hid/spi-hid/spi-hid-core.c | 519 +++++++++++++++++++++++++++++++++++++ 1 file changed, 519 insertions(+) diff --git a/drivers/hid/spi-hid/spi-hid-core.c b/drivers/hid/spi-hid/spi-hid-core.c index d7b4d4adad95..4723b87346d4 100644 --- a/drivers/hid/spi-hid/spi-hid-core.c +++ b/drivers/hid/spi-hid/spi-hid-core.c @@ -20,13 +20,69 @@ * Copyright (c) 2006-2010 Jiri Kosina */ +#include <linux/completion.h> +#include <linux/crc32.h> #include <linux/device.h> +#include <linux/err.h> #include <linux/hid.h> #include <linux/hid-over-spi.h> #include <linux/interrupt.h> +#include <linux/jiffies.h> #include <linux/module.h> +#include <linux/mutex.h> #include <linux/slab.h> #include <linux/spi/spi.h> +#include <linux/string.h> +#include <linux/sysfs.h> +#include <linux/unaligned.h> + +#define SPI_HID_OUTPUT_REPORT_CONTENT_ID_DESC_REQUEST 0x00 + +#define SPI_HID_RESP_TIMEOUT 1000 + +/* Protocol message size constants */ +#define SPI_HID_OUTPUT_HEADER_LEN 8 + +/* flags */ +/* + * ready flag indicates that the FW is ready to accept commands and + * requests. The FW becomes ready after sending the report descriptor. + */ +#define SPI_HID_READY 0 + +/* Raw input buffer with data from the bus */ +struct spi_hid_input_buf { + u8 header[HIDSPI_INPUT_HEADER_SIZE]; + u8 body[HIDSPI_INPUT_BODY_HEADER_SIZE]; + 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[]; +}; + +/* Data necessary to send an output report */ +struct spi_hid_output_report { + u8 report_type; + u16 content_length; + u8 content_id; + u8 *content; +}; + +/* 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; +}; /* struct spi_hid_conf - Conf provided to the core */ struct spi_hid_conf { @@ -61,8 +117,26 @@ struct spi_hid { struct spihid_ops *ops; struct spi_hid_conf *conf; + struct spi_hid_device_descriptor desc; /* HID device descriptor. */ + struct spi_hid_output_buf *output; /* Output buffer. */ + struct spi_hid_input_buf *input; /* Input buffer. */ + struct spi_hid_input_buf *response; /* Response buffer. */ + + u16 response_length; + u16 bufsize; + enum hidspi_power_state power_state; + u8 reset_attempts; /* The number of reset attempts. */ + + unsigned long flags; /* device flags. */ + + /* Control lock to make sure one output transaction at a time. */ + struct mutex output_lock; + struct completion output_done; + + u32 report_descriptor_crc32; /* HID report descriptor crc32 checksum. */ + u32 regulator_error_count; int regulator_last_error; u32 bus_error_count; @@ -70,6 +144,33 @@ struct spi_hid { u32 dir_count; /* device initiated reset count. */ }; +static struct hid_ll_driver spi_hid_ll_driver; + +static void spi_hid_populate_output_header(u8 *buf, + const struct spi_hid_conf *conf, + const struct spi_hid_output_report *report) +{ + buf[0] = conf->write_opcode; + put_unaligned_be24(conf->output_report_address, &buf[1]); + buf[4] = report->report_type; + put_unaligned_le16(report->content_length, &buf[5]); + buf[7] = report->content_id; +} + +static int spi_hid_output(struct spi_hid *shid, const void *buf, u16 length) +{ + int error; + + error = spi_write(shid->spi, buf, length); + + if (error) { + shid->bus_error_count++; + shid->bus_last_error = error; + } + + return error; +} + static const char *spi_hid_power_mode_string(enum hidspi_power_state power_state) { switch (power_state) { @@ -84,11 +185,416 @@ static const char *spi_hid_power_mode_string(enum hidspi_power_state power_state } } +static void spi_hid_stop_hid(struct spi_hid *shid) +{ + struct hid_device *hid = shid->hid; + + shid->hid = NULL; + clear_bit(SPI_HID_READY, &shid->flags); + + if (hid) + hid_destroy_device(hid); +} + +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 error; + + guard(mutex)(&shid->output_lock); + if (report->content_length > shid->desc.max_output_length) { + dev_err(dev, "Output report too big, content_length 0x%x.", + report->content_length); + return -E2BIG; + } + + 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); + + error = spi_hid_output(shid, buf, padded_length); + if (error) + dev_err(dev, "Failed output transfer: %d.", error); + + return error; +} + +static int spi_hid_sync_request(struct spi_hid *shid, + struct spi_hid_output_report *report) +{ + struct device *dev = &shid->spi->dev; + int error; + + error = spi_hid_send_output_report(shid, report); + if (error) + return error; + + error = wait_for_completion_interruptible_timeout(&shid->output_done, + msecs_to_jiffies(SPI_HID_RESP_TIMEOUT)); + if (error == 0) { + dev_err(dev, "Response timed out."); + return -ETIMEDOUT; + } + + return 0; +} + +/* + * 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) +{ + struct device *dev = &shid->spi->dev; + struct spi_hid_output_report report = { + .report_type = REPORT_DESCRIPTOR, + .content_length = 0, + .content_id = SPI_HID_OUTPUT_REPORT_CONTENT_ID_DESC_REQUEST, + .content = NULL, + }; + int ret; + + ret = spi_hid_sync_request(shid, &report); + if (ret) { + dev_err(dev, + "Expected report descriptor not received: %d.", ret); + return ret; + } + + ret = shid->response_length; + if (ret != shid->desc.report_descriptor_length) { + ret = min_t(unsigned int, ret, shid->desc.report_descriptor_length); + dev_err(dev, "Received report descriptor length doesn't match device descriptor field, using min of the two: %d.", + ret); + } + + return ret; +} + +static int spi_hid_create_device(struct spi_hid *shid) +{ + struct hid_device *hid; + struct device *dev = &shid->spi->dev; + int error; + + hid = hid_allocate_device(); + error = PTR_ERR_OR_ZERO(hid); + if (error) { + dev_err(dev, "Failed to allocate hid device: %d.", error); + return error; + } + + 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 %04X:%04X", + hid->vendor, hid->product); + strscpy(hid->phys, dev_name(&shid->spi->dev), sizeof(hid->phys)); + + shid->hid = hid; + + error = hid_add_device(hid); + if (error) { + dev_err(dev, "Failed to add hid device: %d.", error); + /* + * We likely got here because report descriptor request timed + * out. Let's disconnect and destroy the hid_device structure. + */ + spi_hid_stop_hid(shid); + return error; + } + + return 0; +} + +static int spi_hid_get_request(struct spi_hid *shid, u8 content_id) +{ + struct device *dev = &shid->spi->dev; + struct spi_hid_output_report report = { + .report_type = GET_FEATURE, + .content_length = 0, + .content_id = content_id, + .content = NULL, + }; + int error; + + error = spi_hid_sync_request(shid, &report); + if (error) { + dev_err(dev, + "Expected get request response not received! Error %d.", + error); + return error; + } + + return 0; +} + +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 = SET_FEATURE, + .content_length = arg_len, + .content_id = content_id, + .content = arg_buf, + }; + + return spi_hid_sync_request(shid, &report); +} + +/* This is a placeholder. Will be implemented in the next patch. */ static irqreturn_t spi_hid_dev_irq(int irq, void *_shid) { return IRQ_HANDLED; } +static int spi_hid_alloc_buffers(struct spi_hid *shid, size_t report_size) +{ + struct device *dev = &shid->spi->dev; + int inbufsize = sizeof(shid->input->header) + sizeof(shid->input->body) + report_size; + int outbufsize = sizeof(shid->output->header) + report_size; + + // devm_krealloc with __GFP_ZERO ensures the new memory is initialized + shid->output = devm_krealloc(dev, shid->output, outbufsize, GFP_KERNEL | __GFP_ZERO); + shid->input = devm_krealloc(dev, shid->input, inbufsize, GFP_KERNEL | __GFP_ZERO); + shid->response = devm_krealloc(dev, shid->response, inbufsize, GFP_KERNEL | __GFP_ZERO); + + if (!shid->output || !shid->input || !shid->response) + return -ENOMEM; + + shid->bufsize = report_size; + + return 0; +} + +static int spi_hid_get_report_length(struct hid_report *report) +{ + return ((report->size - 1) >> 3) + 1 + + report->device->report_enum[report->type].numbered + 2; +} + +/* + * Traverse the supplied list of reports and find the longest + */ +static void spi_hid_find_max_report(struct hid_device *hid, u32 type, + u16 *max) +{ + struct hid_report *report; + u16 size; + + /* + * We should not rely on wMaxInputLength, as some devices may set it to + * a wrong length. + */ + list_for_each_entry(report, &hid->report_enum[type].report_list, list) { + size = spi_hid_get_report_length(report); + if (*max < size) + *max = size; + } +} + +/* 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); + int error = 0; + u16 bufsize = 0; + + spi_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize); + spi_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize); + spi_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize); + + if (bufsize < HID_MIN_BUFFER_SIZE) { + dev_err(&spi->dev, + "HID_MIN_BUFFER_SIZE > max_input_length (%d).", + bufsize); + return -EINVAL; + } + + if (bufsize > shid->bufsize) { + guard(disable_irq)(&shid->spi->irq); + + error = spi_hid_alloc_buffers(shid, bufsize); + if (error) + return error; + } + + 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); + + set_bit(SPI_HID_READY, &shid->flags); + 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); + + clear_bit(SPI_HID_READY, &shid->flags); + shid->reset_attempts = 0; +} + +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 error = 0; + + guard(mutex)(&shid->output_lock); + if (!shid->hid) + error = -ENODEV; + + return error; +} + +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 error, len; + + len = spi_hid_report_descriptor_request(shid); + if (len < 0) { + dev_err(dev, "Report descriptor request failed, %d.", len); + return len; + } + + /* + * 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. + */ + error = hid_parse_report(hid, (u8 *)shid->response->content, len); + if (error) { + dev_err(dev, "failed parsing report: %d.", error); + return error; + } + shid->report_descriptor_crc32 = crc32_le(0, + (unsigned char const *)shid->response->content, + len); + + return 0; +} + +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; + + switch (reqtype) { + case HID_REQ_SET_REPORT: + if (buf[0] != reportnum) { + dev_err(dev, "report id mismatch."); + return -EINVAL; + } + + ret = spi_hid_set_request(shid, &buf[1], len - 1, + reportnum); + if (ret) { + dev_err(dev, "failed to set report."); + return ret; + } + + ret = len; + break; + case HID_REQ_GET_REPORT: + ret = spi_hid_get_request(shid, reportnum); + if (ret) { + dev_err(dev, "failed to get report."); + return ret; + } + + ret = min_t(size_t, len, + (shid->response->body[1] | (shid->response->body[2] << 8)) + 1); + buf[0] = shid->response->body[3]; + memcpy(&buf[1], &shid->response->content, ret); + break; + default: + dev_err(dev, "invalid request type."); + return -EIO; + } + + return ret; +} + +static int spi_hid_ll_output_report(struct hid_device *hid, __u8 *buf, + size_t len) +{ + 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 = OUTPUT_REPORT, + .content_length = len - 1, + .content_id = buf[0], + .content = &buf[1], + }; + int error; + + if (!test_bit(SPI_HID_READY, &shid->flags)) { + dev_err(dev, "%s called in unready state", __func__); + return -ENODEV; + } + + if (shid->desc.no_output_report_ack) + error = spi_hid_send_output_report(shid, &report); + else + error = spi_hid_sync_request(shid, &report); + + if (error) { + dev_err(dev, "failed to send output report."); + return error; + } + + 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 bus_error_count_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -159,6 +665,15 @@ int spi_hid_core_probe(struct spi_device *spi, struct spihid_ops *ops, spi_set_drvdata(spi, shid); + /* + * we need to allocate the buffer without knowing the maximum + * size of the reports. Let's use SZ_2K, then we do the + * real computation later. + */ + error = spi_hid_alloc_buffers(shid, SZ_2K); + if (error) + return error; + /* * At the end of probe we initialize the device: * 0) assert reset, bias the interrupt line @@ -191,6 +706,8 @@ int spi_hid_core_probe(struct spi_device *spi, struct spihid_ops *ops, dev_dbg(dev, "%s: d3 -> %s.", __func__, spi_hid_power_mode_string(shid->power_state)); + spi_hid_create_device(shid); + return 0; } EXPORT_SYMBOL_GPL(spi_hid_core_probe); @@ -201,6 +718,8 @@ void spi_hid_core_remove(struct spi_device *spi) struct device *dev = &spi->dev; int error; + spi_hid_stop_hid(shid); + shid->ops->assert_reset(shid->ops); error = shid->ops->power_down(shid->ops); if (error) -- 2.53.0.983.g0bb29b3bc5-goog
