diff options
Diffstat (limited to 'drivers/media/usb/em28xx/em28xx-i2c.c')
| -rw-r--r-- | drivers/media/usb/em28xx/em28xx-i2c.c | 116 |
1 files changed, 85 insertions, 31 deletions
diff --git a/drivers/media/usb/em28xx/em28xx-i2c.c b/drivers/media/usb/em28xx/em28xx-i2c.c index 4a24ed08e46a..f784b516ae1c 100644 --- a/drivers/media/usb/em28xx/em28xx-i2c.c +++ b/drivers/media/usb/em28xx/em28xx-i2c.c @@ -76,18 +76,26 @@ static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len) /* trigger write */ ret = dev->em28xx_write_regs(dev, 4 - len, &b2[4 - len], 2 + len); if (ret != 2 + len) { - em28xx_warn("writing to i2c device failed (error=%i)\n", ret); - return -EIO; + em28xx_warn("failed to trigger write to i2c address 0x%x " + "(error=%i)\n", addr, ret); + return (ret < 0) ? ret : -EIO; } /* wait for completion */ for (write_timeout = EM2800_I2C_XFER_TIMEOUT; write_timeout > 0; write_timeout -= 5) { ret = dev->em28xx_read_reg(dev, 0x05); - if (ret == 0x80 + len - 1) + if (ret == 0x80 + len - 1) { return len; + } else if (ret == 0x94 + len - 1) { + return -ENODEV; + } else if (ret < 0) { + em28xx_warn("failed to get i2c transfer status from " + "bridge register (error=%i)\n", ret); + return ret; + } msleep(5); } - em28xx_warn("i2c write timed out\n"); + em28xx_warn("write to i2c device at 0x%x timed out\n", addr); return -EIO; } @@ -168,24 +176,48 @@ static int em2800_i2c_check_for_device(struct em28xx *dev, u8 addr) static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len, int stop) { - int wrcount = 0; int write_timeout, ret; if (len < 1 || len > 64) return -EOPNOTSUPP; + /* NOTE: limited by the USB ctrl message constraints + * Zero length reads always succeed, even if no device is connected */ - wrcount = dev->em28xx_write_regs_req(dev, stop ? 2 : 3, addr, buf, len); + /* Write to i2c device */ + ret = dev->em28xx_write_regs_req(dev, stop ? 2 : 3, addr, buf, len); + if (ret != len) { + if (ret < 0) { + em28xx_warn("writing to i2c device at 0x%x failed " + "(error=%i)\n", addr, ret); + return ret; + } else { + em28xx_warn("%i bytes write to i2c device at 0x%x " + "requested, but %i bytes written\n", + len, addr, ret); + return -EIO; + } + } - /* Seems to be required after a write */ + /* Check success of the i2c operation */ for (write_timeout = EM2800_I2C_XFER_TIMEOUT; write_timeout > 0; write_timeout -= 5) { ret = dev->em28xx_read_reg(dev, 0x05); - if (!ret) - break; + if (ret == 0) { /* success */ + return len; + } else if (ret == 0x10) { + return -ENODEV; + } else if (ret < 0) { + em28xx_warn("failed to read i2c transfer status from " + "bridge (error=%i)\n", ret); + return ret; + } msleep(5); + /* NOTE: do we really have to wait for success ? + Never seen anything else than 0x00 or 0x10 + (even with high payload) ... */ } - - return wrcount; + em28xx_warn("write to i2c device at 0x%x timed out\n", addr); + return -EIO; } /* @@ -198,15 +230,40 @@ static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len) if (len < 1 || len > 64) return -EOPNOTSUPP; + /* NOTE: limited by the USB ctrl message constraints + * Zero length reads always succeed, even if no device is connected */ + /* Read data from i2c device */ ret = dev->em28xx_read_reg_req_len(dev, 2, addr, buf, len); + if (ret != len) { + if (ret < 0) { + em28xx_warn("reading from i2c device at 0x%x failed " + "(error=%i)\n", addr, ret); + return ret; + } else { + em28xx_warn("%i bytes requested from i2c device at " + "0x%x, but %i bytes received\n", + len, addr, ret); + return -EIO; + } + } + + /* Check success of the i2c operation */ + ret = dev->em28xx_read_reg(dev, 0x05); if (ret < 0) { - em28xx_warn("reading i2c device failed (error=%i)\n", ret); + em28xx_warn("failed to read i2c transfer status from " + "bridge (error=%i)\n", ret); return ret; } - if (dev->em28xx_read_reg(dev, 0x5) != 0) - return -ENODEV; - return ret; + if (ret > 0) { + if (ret == 0x10) { + return -ENODEV; + } else { + em28xx_warn("unknown i2c error (status=%i)\n", ret); + return -EIO; + } + } + return len; } /* @@ -216,15 +273,12 @@ static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len) static int em28xx_i2c_check_for_device(struct em28xx *dev, u16 addr) { int ret; + u8 buf; - ret = dev->em28xx_read_reg_req(dev, 2, addr); - if (ret < 0) { - em28xx_warn("reading from i2c device failed (error=%i)\n", ret); - return ret; - } - if (dev->em28xx_read_reg(dev, 0x5) != 0) - return -ENODEV; - return 0; + ret = em28xx_i2c_recv_bytes(dev, addr, &buf, 1); + if (ret == 1) + return 0; + return (ret < 0) ? ret : -EIO; } /* @@ -249,11 +303,11 @@ static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap, rc = em2800_i2c_check_for_device(dev, addr); else rc = em28xx_i2c_check_for_device(dev, addr); - if (rc < 0) { - dprintk2(2, " no device\n"); + if (rc == -ENODEV) { + if (i2c_debug >= 2) + printk(" no device\n"); return rc; } - } else if (msgs[i].flags & I2C_M_RD) { /* read bytes */ if (dev->board.is_em2800) @@ -284,16 +338,16 @@ static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap, msgs[i].len, i == num - 1); } - if (rc < 0) - goto err; + if (rc < 0) { + if (i2c_debug >= 2) + printk(" ERROR: %i\n", rc); + return rc; + } if (i2c_debug >= 2) printk("\n"); } return num; -err: - dprintk2(2, " ERROR: %i\n", rc); - return rc; } /* based on linux/sunrpc/svcauth.h and linux/hash.h |