These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / drivers / hid / hid-cp2112.c

diff --git a/kernel/drivers/hid/hid-cp2112.c b/kernel/drivers/hid/hid-cp2112.c
index 39bf747..7afc3fc 100644 (file)
--- a/kernel/drivers/hid/hid-cp2112.c
+++ b/kernel/drivers/hid/hid-cp2112.c
@@ -156,6 +156,7 @@ struct cp2112_device {
        wait_queue_head_t wait;
        u8 read_data[61];
        u8 read_length;
+       u8 hwversion;
        int xfer_status;
        atomic_t read_avail;
        atomic_t xfer_avail;
@@ -446,6 +447,24 @@ static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,
        return data_length + 3;
 }
 
+static int cp2112_i2c_write_read_req(void *buf, u8 slave_address,
+                                    u8 *addr, int addr_length,
+                                    int read_length)
+{
+       struct cp2112_write_read_req_report *report = buf;
+
+       if (read_length < 1 || read_length > 512 ||
+           addr_length > sizeof(report->target_address))
+               return -EINVAL;
+
+       report->report = CP2112_DATA_WRITE_READ_REQUEST;
+       report->slave_address = slave_address << 1;
+       report->length = cpu_to_be16(read_length);
+       report->target_address_length = addr_length;
+       memcpy(report->target_address, addr, addr_length);
+       return addr_length + 5;
+}
+
 static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
                           int num)
 {
@@ -453,26 +472,46 @@ static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
        struct hid_device *hdev = dev->hdev;
        u8 buf[64];
        ssize_t count;
+       ssize_t read_length = 0;
+       u8 *read_buf = NULL;
        unsigned int retries;
        int ret;
 
        hid_dbg(hdev, "I2C %d messages\n", num);
 
-       if (num != 1) {
+       if (num == 1) {
+               if (msgs->flags & I2C_M_RD) {
+                       hid_dbg(hdev, "I2C read %#04x len %d\n",
+                               msgs->addr, msgs->len);
+                       read_length = msgs->len;
+                       read_buf = msgs->buf;
+                       count = cp2112_read_req(buf, msgs->addr, msgs->len);
+               } else {
+                       hid_dbg(hdev, "I2C write %#04x len %d\n",
+                               msgs->addr, msgs->len);
+                       count = cp2112_i2c_write_req(buf, msgs->addr,
+                                                    msgs->buf, msgs->len);
+               }
+               if (count < 0)
+                       return count;
+       } else if (dev->hwversion > 1 &&  /* no repeated start in rev 1 */
+                  num == 2 &&
+                  msgs[0].addr == msgs[1].addr &&
+                  !(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD)) {
+               hid_dbg(hdev, "I2C write-read %#04x wlen %d rlen %d\n",
+                       msgs[0].addr, msgs[0].len, msgs[1].len);
+               read_length = msgs[1].len;
+               read_buf = msgs[1].buf;
+               count = cp2112_i2c_write_read_req(buf, msgs[0].addr,
+                               msgs[0].buf, msgs[0].len, msgs[1].len);
+               if (count < 0)
+                       return count;
+       } else {
                hid_err(hdev,
                        "Multi-message I2C transactions not supported\n");
                return -EOPNOTSUPP;
        }
 
-       if (msgs->flags & I2C_M_RD)
-               count = cp2112_read_req(buf, msgs->addr, msgs->len);
-       else
-               count = cp2112_i2c_write_req(buf, msgs->addr, msgs->buf,
-                                            msgs->len);
-
-       if (count < 0)
-               return count;
-
        ret = hid_hw_power(hdev, PM_HINT_FULLON);
        if (ret < 0) {
                hid_err(hdev, "power management error: %d\n", ret);
@@ -508,21 +547,34 @@ static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
                goto power_normal;
        }
 
-       if (!(msgs->flags & I2C_M_RD))
-               goto finish;
-
-       ret = cp2112_read(dev, msgs->buf, msgs->len);
-       if (ret < 0)
-               goto power_normal;
-       if (ret != msgs->len) {
-               hid_warn(hdev, "short read: %d < %d\n", ret, msgs->len);
-               ret = -EIO;
-               goto power_normal;
+       for (count = 0; count < read_length;) {
+               ret = cp2112_read(dev, read_buf + count, read_length - count);
+               if (ret < 0)
+                       goto power_normal;
+               if (ret == 0) {
+                       hid_err(hdev, "read returned 0\n");
+                       ret = -EIO;
+                       goto power_normal;
+               }
+               count += ret;
+               if (count > read_length) {
+                       /*
+                        * The hardware returned too much data.
+                        * This is mostly harmless because cp2112_read()
+                        * has a limit check so didn't overrun our
+                        * buffer.  Nevertheless, we return an error
+                        * because something is seriously wrong and
+                        * it shouldn't go unnoticed.
+                        */
+                       hid_err(hdev, "long read: %d > %zd\n",
+                               ret, read_length - count + ret);
+                       ret = -EIO;
+                       goto power_normal;
+               }
        }
 
-finish:
        /* return the number of transferred messages */
-       ret = 1;
+       ret = num;
 
 power_normal:
        hid_hw_power(hdev, PM_HINT_NORMAL);
@@ -1030,6 +1082,7 @@ static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
        dev->adap.dev.parent    = &hdev->dev;
        snprintf(dev->adap.name, sizeof(dev->adap.name),
                 "CP2112 SMBus Bridge on hiddev%d", hdev->minor);
+       dev->hwversion = buf[2];
        init_waitqueue_head(&dev->wait);
 
        hid_device_io_start(hdev);