greybus: hid: add HID class driver
authorViresh Kumar <viresh.kumar@linaro.org>
Mon, 16 Mar 2015 11:19:37 +0000 (16:49 +0530)
committerGreg Kroah-Hartman <greg@kroah.com>
Mon, 16 Mar 2015 19:29:44 +0000 (20:29 +0100)
This adds HID transport layer driver for Greybus. Most of the stuff is
implemented, but is untested.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
drivers/staging/greybus/Makefile
drivers/staging/greybus/gpb.c
drivers/staging/greybus/hid.c [new file with mode: 0644]
drivers/staging/greybus/protocol.h

index a22ad69..6cb08ae 100644 (file)
@@ -14,6 +14,7 @@ gb-phy-y :=   gpb.o           \
                uart.o  \
                pwm.o   \
                gpio.o  \
+               hid.o   \
                i2c.o   \
                spi.o   \
                usb.o
index 6177105..931d739 100644 (file)
@@ -49,8 +49,14 @@ static int __init gpbridge_init(void)
                pr_err("error initializing spi protocol\n");
                goto error_spi;
        }
+       if (gb_hid_protocol_init()) {
+               pr_err("error initializing hid protocol\n");
+               goto error_hid;
+       }
        return 0;
 
+error_hid:
+       gb_spi_protocol_exit();
 error_spi:
        gb_i2c_protocol_exit();
 error_i2c:
@@ -69,6 +75,7 @@ error_gpio:
 
 static void __exit gpbridge_exit(void)
 {
+       gb_hid_protocol_exit();
        gb_spi_protocol_exit();
        gb_i2c_protocol_exit();
        gb_usb_protocol_exit();
diff --git a/drivers/staging/greybus/hid.c b/drivers/staging/greybus/hid.c
new file mode 100644 (file)
index 0000000..17ca476
--- /dev/null
@@ -0,0 +1,565 @@
+/*
+ * HID class driver for the Greybus.
+ *
+ * Copyright 2014 Google Inc.
+ * Copyright 2014 Linaro Ltd.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#include <linux/bitops.h>
+#include <linux/hid.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+
+#include "greybus.h"
+
+/* Version of the Greybus hid protocol we support */
+#define GB_HID_VERSION_MAJOR           0x00
+#define GB_HID_VERSION_MINOR           0x01
+
+/* Greybus HID request types */
+#define GB_HID_TYPE_INVALID            0x00
+#define GB_HID_TYPE_PROTOCOL_VERSION   0x01
+#define GB_HID_TYPE_GET_DESC           0x02
+#define GB_HID_TYPE_GET_REPORT_DESC    0x03
+#define GB_HID_TYPE_PWR_ON             0x04
+#define GB_HID_TYPE_PWR_OFF            0x05
+#define GB_HID_TYPE_GET_REPORT         0x06
+#define GB_HID_TYPE_SET_REPORT         0x07    /* Feature or Output, via control pipe */
+#define GB_HID_TYPE_OUTPUT_REPORT      0x08    /* Output report via interrupt pipe */
+#define GB_HID_TYPE_IRQ_EVENT          0x09
+#define GB_HID_TYPE_RESPONSE           0x80    /* OR'd with rest */
+
+/* Report type */
+#define GB_HID_INPUT_REPORT            0
+#define GB_HID_OUTPUT_REPORT           1
+#define GB_HID_FEATURE_REPORT          2
+
+/* Different request/response structures */
+/* HID get descriptor response */
+struct gb_hid_desc_response {
+       __u8                            bLength;
+       __le16                          wReportDescLength;
+       __le16                          bcdHID;
+       __le16                          wProductID;
+       __le16                          wVendorID;
+       __u8                            bCountryCode;
+} __packed;
+
+/* HID get report request/response */
+struct gb_hid_get_report_request {
+       __u8                            report_type;
+       __u8                            report_id;
+};
+
+/* HID set report request */
+struct gb_hid_set_report_request {
+       __u8                            report_type;
+       __u8                            report_id;
+       __u8                            report[0];
+};
+
+/* HID input report request, via interrupt pipe */
+struct gb_hid_input_report_request {
+       __u8                            report[0];
+};
+
+/* Greybus HID device's structure */
+struct gb_hid {
+       struct gb_connection            *connection;
+       u8                              version_major;
+       u8                              version_minor;
+
+       struct hid_device               *hid;
+       struct gb_hid_desc_response     hdesc;
+
+       unsigned long                   flags;
+#define GB_HID_STARTED                 0x01
+#define GB_HID_READ_PENDING            0x04
+
+       unsigned int                    bufsize;
+       char                            *inbuf;
+};
+
+static DEFINE_MUTEX(gb_hid_open_mutex);
+
+/* Routines to get controller's infomation over greybus */
+
+/* Define get_version() routine */
+define_get_version(gb_hid, HID);
+
+/* Operations performed on greybus */
+static int gb_hid_get_desc(struct gb_hid *ghid)
+{
+       return gb_operation_sync(ghid->connection, GB_HID_TYPE_GET_DESC, NULL,
+                                0, &ghid->hdesc, sizeof(ghid->hdesc));
+}
+
+static int gb_hid_get_report_desc(struct gb_hid *ghid, char *rdesc)
+{
+       return gb_operation_sync(ghid->connection, GB_HID_TYPE_GET_REPORT_DESC,
+                                NULL, 0, rdesc,
+                                le16_to_cpu(ghid->hdesc.wReportDescLength));
+}
+
+static int gb_hid_set_power(struct gb_hid *ghid, int type)
+{
+       return gb_operation_sync(ghid->connection, type, NULL, 0, NULL, 0);
+}
+
+static int gb_hid_get_report(struct gb_hid *ghid, u8 report_type, u8 report_id,
+                            unsigned char *buf, int len)
+{
+       struct gb_hid_get_report_request request;
+
+       request.report_type = report_type;
+       request.report_id = report_id;
+
+       return gb_operation_sync(ghid->connection, GB_HID_TYPE_GET_REPORT,
+                                &request, sizeof(request), buf, len);
+}
+
+/*
+ * @raw: true: use SET_REPORT HID command, false: send plain OUTPUT report.
+ *
+ * Use SET_REPORT for feature reports or if the device does not support the
+ * output plain report.
+ */
+static int gb_hid_set_report(struct gb_hid *ghid, u8 report_type, u8 report_id,
+                            unsigned char *buf, int len, int raw)
+{
+       struct gb_hid_set_report_request *request;
+       struct gb_operation *operation;
+       int ret, size = sizeof(*request) + len - 1;
+       int type = raw ? GB_HID_TYPE_SET_REPORT : GB_HID_TYPE_OUTPUT_REPORT;
+
+       operation = gb_operation_create(ghid->connection, type, size, 0);
+       if (!operation)
+               return -ENOMEM;
+
+       request = operation->request->payload;
+       request->report_type = report_type;
+       request->report_id = report_id;
+       memcpy(request->report, buf, len);
+
+       ret = gb_operation_request_send_sync(operation);
+       if (ret)
+               pr_err("%s: operation failed (%d)\n", __func__, ret);
+       else
+               ret = len;
+
+       gb_operation_destroy(operation);
+       return ret;
+}
+
+static void gb_hid_irq_handler(u8 type, struct gb_operation *op)
+{
+       struct gb_connection *connection = op->connection;
+       struct gb_hid *ghid = connection->private;
+       struct gb_hid_input_report_request *request = op->request->payload;
+       int ret, size;
+
+       if (type != GB_HID_TYPE_IRQ_EVENT) {
+               pr_err("unsupported unsolicited request\n");
+               return;
+       }
+
+       ret = gb_operation_response_send(op, 0);
+       if (ret)
+               pr_err("%s: error %d sending response status %d\n", __func__,
+                      ret, 0);
+
+       size = request->report[0] | request->report[1] << 8;
+       if (!size) {
+               pr_err("%s: size can't be zero.\n", __func__);
+               return;
+       }
+
+       if (test_bit(GB_HID_STARTED, &ghid->flags))
+               hid_input_report(ghid->hid, HID_INPUT_REPORT,
+                                request->report + 2, size - 2, 1);
+}
+
+
+static int gb_hid_report_len(struct hid_report *report)
+{
+       return ((report->size - 1) >> 3) + 1 +
+               report->device->report_enum[report->type].numbered;
+}
+
+static void gb_hid_find_max_report(struct hid_device *hid, unsigned int type,
+                                  unsigned int *max)
+{
+       struct hid_report *report;
+       unsigned int size;
+
+       list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
+               size = gb_hid_report_len(report);
+               if (*max < size)
+                       *max = size;
+       }
+}
+
+static void gb_hid_free_buffers(struct gb_hid *ghid)
+{
+       kfree(ghid->inbuf);
+       ghid->inbuf = NULL;
+       ghid->bufsize = 0;
+}
+
+static int gb_hid_alloc_buffers(struct gb_hid *ghid, size_t bufsize)
+{
+       ghid->inbuf = kzalloc(bufsize, GFP_KERNEL);
+       if (!ghid->inbuf)
+               return -ENOMEM;
+
+       ghid->bufsize = bufsize;
+
+       return 0;
+}
+
+/* Routines dealing with reports */
+static void gb_hid_init_report(struct gb_hid *ghid, struct hid_report *report)
+{
+       unsigned int size;
+
+       size = gb_hid_report_len(report);
+       if (gb_hid_get_report(ghid, report->type, report->id, ghid->inbuf,
+                             size))
+               return;
+
+       /*
+        * hid->driver_lock is held as we are in probe function,
+        * we just need to setup the input fields, so using
+        * hid_report_raw_event is safe.
+        */
+       hid_report_raw_event(ghid->hid, report->type, ghid->inbuf, size, 1);
+}
+
+static void gb_hid_init_reports(struct gb_hid *ghid)
+{
+       struct hid_device *hid = ghid->hid;
+       struct hid_report *report;
+
+       list_for_each_entry(report,
+               &hid->report_enum[HID_INPUT_REPORT].report_list, list)
+               gb_hid_init_report(ghid, report);
+
+       list_for_each_entry(report,
+               &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
+               gb_hid_init_report(ghid, report);
+}
+
+static int __gb_hid_get_raw_report(struct hid_device *hid,
+               unsigned char report_number, __u8 *buf, size_t count,
+               unsigned char report_type)
+{
+       struct gb_hid *ghid = hid->driver_data;
+       int ret;
+
+       if (report_type == HID_OUTPUT_REPORT)
+               return -EINVAL;
+
+       ret = gb_hid_get_report(ghid, report_type, report_number, buf, count);
+       if (!ret)
+               ret = count;
+
+       return ret;
+}
+
+static int __gb_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
+                                     size_t len, unsigned char report_type,
+                                     bool raw)
+{
+       struct gb_hid *ghid = hid->driver_data;
+       int report_id = buf[0];
+       int ret;
+
+       if (report_type == HID_INPUT_REPORT)
+               return -EINVAL;
+
+       if (report_id) {
+               buf++;
+               len--;
+       }
+
+       ret = gb_hid_set_report(ghid, report_type, report_id, buf, len, raw);
+       if (report_id && ret >= 0)
+               ret++; /* add report_id to the number of transfered bytes */
+
+       return 0;
+}
+
+static int gb_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
+                              __u8 *buf, size_t len, unsigned char rtype,
+                              int reqtype)
+{
+       switch (reqtype) {
+       case HID_REQ_GET_REPORT:
+               return __gb_hid_get_raw_report(hid, reportnum, buf, len, rtype);
+       case HID_REQ_SET_REPORT:
+               if (buf[0] != reportnum)
+                       return -EINVAL;
+               return __gb_hid_output_raw_report(hid, buf, len, rtype, true);
+       default:
+               return -EIO;
+       }
+}
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,15,0)
+static int gb_hid_output_report(struct hid_device *hid, __u8 *buf, size_t len)
+{
+       return __gb_hid_output_raw_report(hid, buf, len, HID_OUTPUT_REPORT,
+                                         false);
+}
+
+#else
+
+static int gb_hid_get_raw_report(struct hid_device *hid,
+                                  unsigned char reportnum, __u8 *buf,
+                                  size_t len, unsigned char rtype)
+{
+       return gb_hid_raw_request(hid, reportnum, buf, len, rtype,
+                                 HID_REQ_GET_REPORT);
+}
+
+static int gb_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
+                                   size_t len, unsigned char rtype)
+{
+       return gb_hid_raw_request(hid, buf[0], buf, len, rtype,
+                                 HID_REQ_SET_REPORT);
+}
+#endif
+
+/* HID Callbacks */
+static int gb_hid_parse(struct hid_device *hid)
+{
+       struct gb_hid *ghid = hid->driver_data;
+       unsigned int rsize;
+       char *rdesc;
+       int ret;
+
+       rsize = le16_to_cpu(ghid->hdesc.wReportDescLength);
+       if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
+               dbg_hid("weird size of report descriptor (%u)\n", rsize);
+               return -EINVAL;
+       }
+
+       rdesc = kzalloc(rsize, GFP_KERNEL);
+       if (!rdesc) {
+               dbg_hid("couldn't allocate rdesc memory\n");
+               return -ENOMEM;
+       }
+
+       ret = gb_hid_get_report_desc(ghid, rdesc);
+       if (ret) {
+               hid_err(hid, "reading report descriptor failed\n");
+               goto free_rdesc;
+       }
+
+       ret = hid_parse_report(hid, rdesc, rsize);
+       if (ret)
+               dbg_hid("parsing report descriptor failed\n");
+
+free_rdesc:
+       kfree(rdesc);
+
+       return ret;
+}
+
+static int gb_hid_start(struct hid_device *hid)
+{
+       struct gb_hid *ghid = hid->driver_data;
+       unsigned int bufsize = HID_MIN_BUFFER_SIZE;
+       int ret;
+
+       gb_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
+       gb_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
+       gb_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
+
+       if (bufsize > HID_MAX_BUFFER_SIZE)
+               bufsize = HID_MAX_BUFFER_SIZE;
+
+       ret = gb_hid_alloc_buffers(ghid, bufsize);
+       if (ret)
+               return ret;
+
+       if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
+               gb_hid_init_reports(ghid);
+
+       return 0;
+}
+
+static void gb_hid_stop(struct hid_device *hid)
+{
+       struct gb_hid *ghid = hid->driver_data;
+
+       gb_hid_free_buffers(ghid);
+}
+
+static int gb_hid_open(struct hid_device *hid)
+{
+       struct gb_hid *ghid = hid->driver_data;
+       int ret = 0;
+
+       mutex_lock(&gb_hid_open_mutex);
+       if (!hid->open++) {
+               ret = gb_hid_set_power(ghid, GB_HID_TYPE_PWR_ON);
+               if (ret < 0)
+                       hid->open--;
+               else
+                       set_bit(GB_HID_STARTED, &ghid->flags);
+       }
+       mutex_unlock(&gb_hid_open_mutex);
+
+       return ret;
+}
+
+static void gb_hid_close(struct hid_device *hid)
+{
+       struct gb_hid *ghid = hid->driver_data;
+
+       /*
+        * Protecting hid->open to make sure we don't restart data acquistion
+        * due to a resumption we no longer care about..
+        */
+       mutex_lock(&gb_hid_open_mutex);
+       if (!--hid->open) {
+               clear_bit(GB_HID_STARTED, &ghid->flags);
+
+               /* Save some power */
+               WARN_ON(gb_hid_set_power(ghid, GB_HID_TYPE_PWR_OFF));
+       }
+       mutex_unlock(&gb_hid_open_mutex);
+}
+
+static int gb_hid_power(struct hid_device *hid, int lvl)
+{
+       struct gb_hid *ghid = hid->driver_data;
+
+       switch (lvl) {
+       case PM_HINT_FULLON:
+               return gb_hid_set_power(ghid, GB_HID_TYPE_PWR_ON);
+       case PM_HINT_NORMAL:
+               return gb_hid_set_power(ghid, GB_HID_TYPE_PWR_OFF);
+       }
+
+       return 0;
+}
+
+/* HID structure to pass callbacks */
+static struct hid_ll_driver gb_hid_ll_driver = {
+       .parse = gb_hid_parse,
+       .start = gb_hid_start,
+       .stop = gb_hid_stop,
+       .open = gb_hid_open,
+       .close = gb_hid_close,
+       .power = gb_hid_power,
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,15,0)
+       .output_report = gb_hid_output_report,
+       .raw_request = gb_hid_raw_request,
+#endif
+};
+
+static int gb_hid_init(struct gb_hid *ghid)
+{
+       struct hid_device *hid = ghid->hid;
+       int ret;
+
+       ret = get_version(ghid);
+       if (ret)
+               return ret;
+
+       ret = gb_hid_get_desc(ghid);
+       if (ret)
+               return ret;
+
+       hid->version = le16_to_cpu(ghid->hdesc.bcdHID);
+       hid->vendor = le16_to_cpu(ghid->hdesc.wVendorID);
+       hid->product = le16_to_cpu(ghid->hdesc.wProductID);
+       hid->country = ghid->hdesc.bCountryCode;
+
+       hid->driver_data = ghid;
+       hid->ll_driver = &gb_hid_ll_driver;
+       hid->dev.parent = &ghid->connection->dev;
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0)
+       hid->hid_get_raw_report = gb_hid_get_raw_report;
+       hid->hid_output_raw_report = gb_hid_output_raw_report;
+#endif
+//     hid->bus = BUS_GREYBUS; /* Need a bustype for GREYBUS in <linux/input.h> */
+
+       /* Set HID device's name */
+       snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
+                dev_name(&ghid->connection->dev), hid->vendor, hid->product);
+
+       return 0;
+}
+
+static int gb_hid_connection_init(struct gb_connection *connection)
+{
+       struct hid_device *hid;
+       struct gb_hid *ghid;
+       int ret;
+
+       ghid = kzalloc(sizeof(*ghid), GFP_KERNEL);
+       if (!ghid)
+               return -ENOMEM;
+
+       hid = hid_allocate_device();
+       if (IS_ERR(hid)) {
+               ret = PTR_ERR(hid);
+               goto free_ghid;
+       }
+
+       connection->private = ghid;
+       ghid->connection = connection;
+       ghid->hid = hid;
+
+       ret = gb_hid_init(ghid);
+       if (ret)
+               goto destroy_hid;
+
+       ret = hid_add_device(hid);
+       if (!ret)
+               return 0;
+
+       hid_err(hid, "can't add hid device: %d\n", ret);
+
+destroy_hid:
+       hid_destroy_device(hid);
+free_ghid:
+       kfree(ghid);
+
+       return ret;
+}
+
+static void gb_hid_connection_exit(struct gb_connection *connection)
+{
+       struct gb_hid *ghid = connection->private;
+
+       hid_destroy_device(ghid->hid);
+       kfree(ghid);
+}
+
+static struct gb_protocol hid_protocol = {
+       .name                   = "hid",
+       .id                     = GREYBUS_PROTOCOL_HID,
+       .major                  = 0,
+       .minor                  = 1,
+       .connection_init        = gb_hid_connection_init,
+       .connection_exit        = gb_hid_connection_exit,
+       .request_recv           = gb_hid_irq_handler,
+};
+
+int gb_hid_protocol_init(void)
+{
+       return gb_protocol_register(&hid_protocol);
+}
+
+void gb_hid_protocol_exit(void)
+{
+       gb_protocol_deregister(&hid_protocol);
+}
index 2d01000..a74afef 100644 (file)
@@ -84,6 +84,9 @@ extern void gb_i2c_protocol_exit(void);
 extern int gb_spi_protocol_init(void);
 extern void gb_spi_protocol_exit(void);
 
+extern int gb_hid_protocol_init(void);
+extern void gb_hid_protocol_exit(void);
+
 #define gb_protocol_driver(__protocol)                 \
 static int __init protocol_init(void)                  \
 {                                                      \