Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / media / usb / em28xx / em28xx-i2c.c
diff --git a/kernel/drivers/media/usb/em28xx/em28xx-i2c.c b/kernel/drivers/media/usb/em28xx/em28xx-i2c.c
new file mode 100644 (file)
index 0000000..a19b5c8
--- /dev/null
@@ -0,0 +1,989 @@
+/*
+   em28xx-i2c.c - driver for Empia EM2800/EM2820/2840 USB video capture devices
+
+   Copyright (C) 2005 Ludovico Cavedon <cavedon@sssup.it>
+                     Markus Rechberger <mrechberger@gmail.com>
+                     Mauro Carvalho Chehab <mchehab@infradead.org>
+                     Sascha Sommer <saschasommer@freenet.de>
+   Copyright (C) 2013 Frank Schäfer <fschaefer.oss@googlemail.com>
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/usb.h>
+#include <linux/i2c.h>
+#include <linux/jiffies.h>
+
+#include "em28xx.h"
+#include "tuner-xc2028.h"
+#include <media/v4l2-common.h>
+#include <media/tuner.h>
+
+/* ----------------------------------------------------------- */
+
+static unsigned int i2c_scan;
+module_param(i2c_scan, int, 0444);
+MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
+
+static unsigned int i2c_debug;
+module_param(i2c_debug, int, 0644);
+MODULE_PARM_DESC(i2c_debug, "i2c debug message level (1: normal debug, 2: show I2C transfers)");
+
+/*
+ * em2800_i2c_send_bytes()
+ * send up to 4 bytes to the em2800 i2c device
+ */
+static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
+{
+       unsigned long timeout = jiffies + msecs_to_jiffies(EM28XX_I2C_XFER_TIMEOUT);
+       int ret;
+       u8 b2[6];
+
+       if (len < 1 || len > 4)
+               return -EOPNOTSUPP;
+
+       BUG_ON(len < 1 || len > 4);
+       b2[5] = 0x80 + len - 1;
+       b2[4] = addr;
+       b2[3] = buf[0];
+       if (len > 1)
+               b2[2] = buf[1];
+       if (len > 2)
+               b2[1] = buf[2];
+       if (len > 3)
+               b2[0] = buf[3];
+
+       /* trigger write */
+       ret = dev->em28xx_write_regs(dev, 4 - len, &b2[4 - len], 2 + len);
+       if (ret != 2 + len) {
+               em28xx_warn("failed to trigger write to i2c address 0x%x (error=%i)\n",
+                           addr, ret);
+               return (ret < 0) ? ret : -EIO;
+       }
+       /* wait for completion */
+       while (time_is_after_jiffies(timeout)) {
+               ret = dev->em28xx_read_reg(dev, 0x05);
+               if (ret == 0x80 + len - 1)
+                       return len;
+               if (ret == 0x94 + len - 1) {
+                       if (i2c_debug == 1)
+                               em28xx_warn("R05 returned 0x%02x: I2C ACK error\n",
+                                           ret);
+                       return -ENXIO;
+               }
+               if (ret < 0) {
+                       em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
+                                   ret);
+                       return ret;
+               }
+               msleep(5);
+       }
+       if (i2c_debug)
+               em28xx_warn("write to i2c device at 0x%x timed out\n", addr);
+       return -ETIMEDOUT;
+}
+
+/*
+ * em2800_i2c_recv_bytes()
+ * read up to 4 bytes from the em2800 i2c device
+ */
+static int em2800_i2c_recv_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
+{
+       unsigned long timeout = jiffies + msecs_to_jiffies(EM28XX_I2C_XFER_TIMEOUT);
+       u8 buf2[4];
+       int ret;
+       int i;
+
+       if (len < 1 || len > 4)
+               return -EOPNOTSUPP;
+
+       /* trigger read */
+       buf2[1] = 0x84 + len - 1;
+       buf2[0] = addr;
+       ret = dev->em28xx_write_regs(dev, 0x04, buf2, 2);
+       if (ret != 2) {
+               em28xx_warn("failed to trigger read from i2c address 0x%x (error=%i)\n",
+                           addr, ret);
+               return (ret < 0) ? ret : -EIO;
+       }
+
+       /* wait for completion */
+       while (time_is_after_jiffies(timeout)) {
+               ret = dev->em28xx_read_reg(dev, 0x05);
+               if (ret == 0x84 + len - 1)
+                       break;
+               if (ret == 0x94 + len - 1) {
+                       if (i2c_debug == 1)
+                               em28xx_warn("R05 returned 0x%02x: I2C ACK error\n",
+                                           ret);
+                       return -ENXIO;
+               }
+               if (ret < 0) {
+                       em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
+                                   ret);
+                       return ret;
+               }
+               msleep(5);
+       }
+       if (ret != 0x84 + len - 1) {
+               if (i2c_debug)
+                       em28xx_warn("read from i2c device at 0x%x timed out\n",
+                                   addr);
+       }
+
+       /* get the received message */
+       ret = dev->em28xx_read_reg_req_len(dev, 0x00, 4-len, buf2, len);
+       if (ret != len) {
+               em28xx_warn("reading from i2c device at 0x%x failed: couldn't get the received message from the bridge (error=%i)\n",
+                           addr, ret);
+               return (ret < 0) ? ret : -EIO;
+       }
+       for (i = 0; i < len; i++)
+               buf[i] = buf2[len - 1 - i];
+
+       return ret;
+}
+
+/*
+ * em2800_i2c_check_for_device()
+ * check if there is an i2c device at the supplied address
+ */
+static int em2800_i2c_check_for_device(struct em28xx *dev, u8 addr)
+{
+       u8 buf;
+       int ret;
+
+       ret = em2800_i2c_recv_bytes(dev, addr, &buf, 1);
+       if (ret == 1)
+               return 0;
+       return (ret < 0) ? ret : -EIO;
+}
+
+/*
+ * em28xx_i2c_send_bytes()
+ */
+static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
+                                u16 len, int stop)
+{
+       unsigned long timeout = jiffies + msecs_to_jiffies(EM28XX_I2C_XFER_TIMEOUT);
+       int 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
+        */
+
+       /* 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;
+               }
+       }
+
+       /* wait for completion */
+       while (time_is_after_jiffies(timeout)) {
+               ret = dev->em28xx_read_reg(dev, 0x05);
+               if (ret == 0) /* success */
+                       return len;
+               if (ret == 0x10) {
+                       if (i2c_debug == 1)
+                               em28xx_warn("I2C ACK error on writing to addr 0x%02x\n",
+                                           addr);
+                       return -ENXIO;
+               }
+               if (ret < 0) {
+                       em28xx_warn("failed to get i2c transfer status from bridge register (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) ...
+                */
+       }
+
+       if (ret == 0x02 || ret == 0x04) {
+               /* NOTE: these errors seem to be related to clock stretching */
+               if (i2c_debug)
+                       em28xx_warn("write to i2c device at 0x%x timed out (status=%i)\n",
+                                   addr, ret);
+               return -ETIMEDOUT;
+       }
+
+       em28xx_warn("write to i2c device at 0x%x failed with unknown error (status=%i)\n",
+                   addr, ret);
+       return -EIO;
+}
+
+/*
+ * em28xx_i2c_recv_bytes()
+ * read a byte from the i2c device
+ */
+static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len)
+{
+       int 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
+        */
+
+       /* Read data from i2c device */
+       ret = dev->em28xx_read_reg_req_len(dev, 2, addr, buf, len);
+       if (ret < 0) {
+               em28xx_warn("reading from i2c device at 0x%x failed (error=%i)\n",
+                           addr, ret);
+               return ret;
+       }
+       /*
+        * NOTE: some devices with two i2c busses have the bad habit to return 0
+        * bytes if we are on bus B AND there was no write attempt to the
+        * specified slave address before AND no device is present at the
+        * requested slave address.
+        * Anyway, the next check will fail with -ENXIO in this case, so avoid
+        * spamming the system log on device probing and do nothing here.
+        */
+
+       /* Check success of the i2c operation */
+       ret = dev->em28xx_read_reg(dev, 0x05);
+       if (ret == 0) /* success */
+               return len;
+       if (ret < 0) {
+               em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
+                           ret);
+               return ret;
+       }
+       if (ret == 0x10) {
+               if (i2c_debug == 1)
+                       em28xx_warn("I2C ACK error on writing to addr 0x%02x\n",
+                                   addr);
+               return -ENXIO;
+       }
+
+       if (ret == 0x02 || ret == 0x04) {
+               /* NOTE: these errors seem to be related to clock stretching */
+               if (i2c_debug)
+                       em28xx_warn("write to i2c device at 0x%x timed out (status=%i)\n",
+                                   addr, ret);
+               return -ETIMEDOUT;
+       }
+
+       em28xx_warn("write to i2c device at 0x%x failed with unknown error (status=%i)\n",
+                   addr, ret);
+       return -EIO;
+}
+
+/*
+ * em28xx_i2c_check_for_device()
+ * check if there is a i2c_device at the supplied address
+ */
+static int em28xx_i2c_check_for_device(struct em28xx *dev, u16 addr)
+{
+       int ret;
+       u8 buf;
+
+       ret = em28xx_i2c_recv_bytes(dev, addr, &buf, 1);
+       if (ret == 1)
+               return 0;
+       return (ret < 0) ? ret : -EIO;
+}
+
+/*
+ * em25xx_bus_B_send_bytes
+ * write bytes to the i2c device
+ */
+static int em25xx_bus_B_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
+                                  u16 len)
+{
+       int 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
+        */
+
+       /* Set register and write value */
+       ret = dev->em28xx_write_regs_req(dev, 0x06, 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;
+               }
+       }
+       /* Check success */
+       ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
+       /*
+        * NOTE: the only error we've seen so far is
+        * 0x01 when the slave device is not present
+        */
+       if (!ret)
+               return len;
+       else if (ret > 0) {
+               if (i2c_debug == 1)
+                       em28xx_warn("Bus B R08 returned 0x%02x: I2C ACK error\n",
+                                   ret);
+               return -ENXIO;
+       }
+
+       return ret;
+       /*
+        * NOTE: With chip types (other chip IDs) which actually don't support
+        * this operation, it seems to succeed ALWAYS ! (even if there is no
+        * slave device or even no second i2c bus provided)
+        */
+}
+
+/*
+ * em25xx_bus_B_recv_bytes
+ * read bytes from the i2c device
+ */
+static int em25xx_bus_B_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf,
+                                  u16 len)
+{
+       int 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
+        */
+
+       /* Read value */
+       ret = dev->em28xx_read_reg_req_len(dev, 0x06, addr, buf, len);
+       if (ret < 0) {
+               em28xx_warn("reading from i2c device at 0x%x failed (error=%i)\n",
+                           addr, ret);
+               return ret;
+       }
+       /*
+        * NOTE: some devices with two i2c busses have the bad habit to return 0
+        * bytes if we are on bus B AND there was no write attempt to the
+        * specified slave address before AND no device is present at the
+        * requested slave address.
+        * Anyway, the next check will fail with -ENXIO in this case, so avoid
+        * spamming the system log on device probing and do nothing here.
+        */
+
+       /* Check success */
+       ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
+       /*
+        * NOTE: the only error we've seen so far is
+        * 0x01 when the slave device is not present
+        */
+       if (!ret)
+               return len;
+       else if (ret > 0) {
+               if (i2c_debug == 1)
+                       em28xx_warn("Bus B R08 returned 0x%02x: I2C ACK error\n",
+                                   ret);
+               return -ENXIO;
+       }
+
+       return ret;
+       /*
+        * NOTE: With chip types (other chip IDs) which actually don't support
+        * this operation, it seems to succeed ALWAYS ! (even if there is no
+        * slave device or even no second i2c bus provided)
+        */
+}
+
+/*
+ * em25xx_bus_B_check_for_device()
+ * check if there is a i2c device at the supplied address
+ */
+static int em25xx_bus_B_check_for_device(struct em28xx *dev, u16 addr)
+{
+       u8 buf;
+       int ret;
+
+       ret = em25xx_bus_B_recv_bytes(dev, addr, &buf, 1);
+       if (ret < 0)
+               return ret;
+
+       return 0;
+       /*
+        * NOTE: With chips which do not support this operation,
+        * it seems to succeed ALWAYS ! (even if no device connected)
+        */
+}
+
+static inline int i2c_check_for_device(struct em28xx_i2c_bus *i2c_bus, u16 addr)
+{
+       struct em28xx *dev = i2c_bus->dev;
+       int rc = -EOPNOTSUPP;
+
+       if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
+               rc = em28xx_i2c_check_for_device(dev, addr);
+       else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
+               rc = em2800_i2c_check_for_device(dev, addr);
+       else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
+               rc = em25xx_bus_B_check_for_device(dev, addr);
+       return rc;
+}
+
+static inline int i2c_recv_bytes(struct em28xx_i2c_bus *i2c_bus,
+                                struct i2c_msg msg)
+{
+       struct em28xx *dev = i2c_bus->dev;
+       u16 addr = msg.addr << 1;
+       int rc = -EOPNOTSUPP;
+
+       if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
+               rc = em28xx_i2c_recv_bytes(dev, addr, msg.buf, msg.len);
+       else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
+               rc = em2800_i2c_recv_bytes(dev, addr, msg.buf, msg.len);
+       else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
+               rc = em25xx_bus_B_recv_bytes(dev, addr, msg.buf, msg.len);
+       return rc;
+}
+
+static inline int i2c_send_bytes(struct em28xx_i2c_bus *i2c_bus,
+                                struct i2c_msg msg, int stop)
+{
+       struct em28xx *dev = i2c_bus->dev;
+       u16 addr = msg.addr << 1;
+       int rc = -EOPNOTSUPP;
+
+       if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
+               rc = em28xx_i2c_send_bytes(dev, addr, msg.buf, msg.len, stop);
+       else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
+               rc = em2800_i2c_send_bytes(dev, addr, msg.buf, msg.len);
+       else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
+               rc = em25xx_bus_B_send_bytes(dev, addr, msg.buf, msg.len);
+       return rc;
+}
+
+/*
+ * em28xx_i2c_xfer()
+ * the main i2c transfer function
+ */
+static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
+                          struct i2c_msg msgs[], int num)
+{
+       struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
+       struct em28xx *dev = i2c_bus->dev;
+       unsigned bus = i2c_bus->bus;
+       int addr, rc, i;
+       u8 reg;
+
+       /* prevent i2c xfer attempts after device is disconnected
+          some fe's try to do i2c writes/reads from their release
+          interfaces when called in disconnect path */
+       if (dev->disconnected)
+               return -ENODEV;
+
+       rc = rt_mutex_trylock(&dev->i2c_bus_lock);
+       if (rc < 0)
+               return rc;
+
+       /* Switch I2C bus if needed */
+       if (bus != dev->cur_i2c_bus &&
+           i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX) {
+               if (bus == 1)
+                       reg = EM2874_I2C_SECONDARY_BUS_SELECT;
+               else
+                       reg = 0;
+               em28xx_write_reg_bits(dev, EM28XX_R06_I2C_CLK, reg,
+                                     EM2874_I2C_SECONDARY_BUS_SELECT);
+               dev->cur_i2c_bus = bus;
+       }
+
+       if (num <= 0) {
+               rt_mutex_unlock(&dev->i2c_bus_lock);
+               return 0;
+       }
+       for (i = 0; i < num; i++) {
+               addr = msgs[i].addr << 1;
+               if (i2c_debug > 1)
+                       printk(KERN_DEBUG "%s at %s: %s %s addr=%02x len=%d:",
+                              dev->name, __func__ ,
+                              (msgs[i].flags & I2C_M_RD) ? "read" : "write",
+                              i == num - 1 ? "stop" : "nonstop",
+                              addr, msgs[i].len);
+               if (!msgs[i].len) {
+                       /*
+                        * no len: check only for device presence
+                        * This code is only called during device probe.
+                        */
+                       rc = i2c_check_for_device(i2c_bus, addr);
+                       if (rc < 0) {
+                               if (rc == -ENXIO) {
+                                       if (i2c_debug > 1)
+                                               printk(KERN_CONT " no device\n");
+                                       rc = -ENODEV;
+                               } else {
+                                       if (i2c_debug > 1)
+                                               printk(KERN_CONT " ERROR: %i\n", rc);
+                               }
+                               rt_mutex_unlock(&dev->i2c_bus_lock);
+                               return rc;
+                       }
+               } else if (msgs[i].flags & I2C_M_RD) {
+                       /* read bytes */
+                       rc = i2c_recv_bytes(i2c_bus, msgs[i]);
+
+                       if (i2c_debug > 1 && rc >= 0)
+                               printk(KERN_CONT " %*ph",
+                                      msgs[i].len, msgs[i].buf);
+               } else {
+                       if (i2c_debug > 1)
+                               printk(KERN_CONT " %*ph",
+                                      msgs[i].len, msgs[i].buf);
+
+                       /* write bytes */
+                       rc = i2c_send_bytes(i2c_bus, msgs[i], i == num - 1);
+               }
+               if (rc < 0) {
+                       if (i2c_debug > 1)
+                               printk(KERN_CONT " ERROR: %i\n", rc);
+                       rt_mutex_unlock(&dev->i2c_bus_lock);
+                       return rc;
+               }
+               if (i2c_debug > 1)
+                       printk(KERN_CONT "\n");
+       }
+
+       rt_mutex_unlock(&dev->i2c_bus_lock);
+       return num;
+}
+
+/*
+ * based on linux/sunrpc/svcauth.h and linux/hash.h
+ * The original hash function returns a different value, if arch is x86_64
+ * or i386.
+ */
+static inline unsigned long em28xx_hash_mem(char *buf, int length, int bits)
+{
+       unsigned long hash = 0;
+       unsigned long l = 0;
+       int len = 0;
+       unsigned char c;
+
+       do {
+               if (len == length) {
+                       c = (char)len;
+                       len = -1;
+               } else
+                       c = *buf++;
+               l = (l << 8) | c;
+               len++;
+               if ((len & (32 / 8 - 1)) == 0)
+                       hash = ((hash^l) * 0x9e370001UL);
+       } while (len);
+
+       return (hash >> (32 - bits)) & 0xffffffffUL;
+}
+
+/*
+ * Helper function to read data blocks from i2c clients with 8 or 16 bit
+ * address width, 8 bit register width and auto incrementation been activated
+ */
+static int em28xx_i2c_read_block(struct em28xx *dev, unsigned bus, u16 addr,
+                                bool addr_w16, u16 len, u8 *data)
+{
+       int remain = len, rsize, rsize_max, ret;
+       u8 buf[2];
+
+       /* Sanity check */
+       if (addr + remain > (addr_w16 * 0xff00 + 0xff + 1))
+               return -EINVAL;
+       /* Select address */
+       buf[0] = addr >> 8;
+       buf[1] = addr & 0xff;
+       ret = i2c_master_send(&dev->i2c_client[bus], buf + !addr_w16, 1 + addr_w16);
+       if (ret < 0)
+               return ret;
+       /* Read data */
+       if (dev->board.is_em2800)
+               rsize_max = 4;
+       else
+               rsize_max = 64;
+       while (remain > 0) {
+               if (remain > rsize_max)
+                       rsize = rsize_max;
+               else
+                       rsize = remain;
+
+               ret = i2c_master_recv(&dev->i2c_client[bus], data, rsize);
+               if (ret < 0)
+                       return ret;
+
+               remain -= rsize;
+               data += rsize;
+       }
+
+       return len;
+}
+
+static int em28xx_i2c_eeprom(struct em28xx *dev, unsigned bus,
+                            u8 **eedata, u16 *eedata_len)
+{
+       const u16 len = 256;
+       /*
+        * FIXME common length/size for bytes to read, to display, hash
+        * calculation and returned device dataset. Simplifies the code a lot,
+        * but we might have to deal with multiple sizes in the future !
+        */
+       int err;
+       struct em28xx_eeprom *dev_config;
+       u8 buf, *data;
+
+       *eedata = NULL;
+       *eedata_len = 0;
+
+       /* EEPROM is always on i2c bus 0 on all known devices. */
+
+       dev->i2c_client[bus].addr = 0xa0 >> 1;
+
+       /* Check if board has eeprom */
+       err = i2c_master_recv(&dev->i2c_client[bus], &buf, 0);
+       if (err < 0) {
+               em28xx_info("board has no eeprom\n");
+               return -ENODEV;
+       }
+
+       data = kzalloc(len, GFP_KERNEL);
+       if (data == NULL)
+               return -ENOMEM;
+
+       /* Read EEPROM content */
+       err = em28xx_i2c_read_block(dev, bus, 0x0000,
+                                   dev->eeprom_addrwidth_16bit,
+                                   len, data);
+       if (err != len) {
+               em28xx_errdev("failed to read eeprom (err=%d)\n", err);
+               goto error;
+       }
+
+       if (i2c_debug) {
+               /* Display eeprom content */
+               print_hex_dump(KERN_INFO, "eeprom ", DUMP_PREFIX_OFFSET,
+                              16, 1, data, len, true);
+
+               if (dev->eeprom_addrwidth_16bit)
+                       em28xx_info("eeprom %06x: ... (skipped)\n", 256);
+       }
+
+       if (dev->eeprom_addrwidth_16bit &&
+           data[0] == 0x26 && data[3] == 0x00) {
+               /* new eeprom format; size 4-64kb */
+               u16 mc_start;
+               u16 hwconf_offset;
+
+               dev->hash = em28xx_hash_mem(data, len, 32);
+               mc_start = (data[1] << 8) + 4;  /* usually 0x0004 */
+
+               em28xx_info("EEPROM ID = %02x %02x %02x %02x, EEPROM hash = 0x%08lx\n",
+                           data[0], data[1], data[2], data[3], dev->hash);
+               em28xx_info("EEPROM info:\n");
+               em28xx_info("\tmicrocode start address = 0x%04x, boot configuration = 0x%02x\n",
+                           mc_start, data[2]);
+               /*
+                * boot configuration (address 0x0002):
+                * [0]   microcode download speed: 1 = 400 kHz; 0 = 100 kHz
+                * [1]   always selects 12 kb RAM
+                * [2]   USB device speed: 1 = force Full Speed; 0 = auto detect
+                * [4]   1 = force fast mode and no suspend for device testing
+                * [5:7] USB PHY tuning registers; determined by device
+                *       characterization
+                */
+
+               /*
+                * Read hardware config dataset offset from address
+                * (microcode start + 46)
+                */
+               err = em28xx_i2c_read_block(dev, bus, mc_start + 46, 1, 2,
+                                           data);
+               if (err != 2) {
+                       em28xx_errdev("failed to read hardware configuration data from eeprom (err=%d)\n",
+                                     err);
+                       goto error;
+               }
+
+               /* Calculate hardware config dataset start address */
+               hwconf_offset = mc_start + data[0] + (data[1] << 8);
+
+               /* Read hardware config dataset */
+               /*
+                * NOTE: the microcode copy can be multiple pages long, but
+                * we assume the hardware config dataset is the same as in
+                * the old eeprom and not longer than 256 bytes.
+                * tveeprom is currently also limited to 256 bytes.
+                */
+               err = em28xx_i2c_read_block(dev, bus, hwconf_offset, 1, len,
+                                           data);
+               if (err != len) {
+                       em28xx_errdev("failed to read hardware configuration data from eeprom (err=%d)\n",
+                                     err);
+                       goto error;
+               }
+
+               /* Verify hardware config dataset */
+               /* NOTE: not all devices provide this type of dataset */
+               if (data[0] != 0x1a || data[1] != 0xeb ||
+                   data[2] != 0x67 || data[3] != 0x95) {
+                       em28xx_info("\tno hardware configuration dataset found in eeprom\n");
+                       kfree(data);
+                       return 0;
+               }
+
+               /* TODO: decrypt eeprom data for camera bridges (em25xx, em276x+) */
+
+       } else if (!dev->eeprom_addrwidth_16bit &&
+                  data[0] == 0x1a && data[1] == 0xeb &&
+                  data[2] == 0x67 && data[3] == 0x95) {
+               dev->hash = em28xx_hash_mem(data, len, 32);
+               em28xx_info("EEPROM ID = %02x %02x %02x %02x, EEPROM hash = 0x%08lx\n",
+                           data[0], data[1], data[2], data[3], dev->hash);
+               em28xx_info("EEPROM info:\n");
+       } else {
+               em28xx_info("unknown eeprom format or eeprom corrupted !\n");
+               err = -ENODEV;
+               goto error;
+       }
+
+       *eedata = data;
+       *eedata_len = len;
+       dev_config = (void *)*eedata;
+
+       switch (le16_to_cpu(dev_config->chip_conf) >> 4 & 0x3) {
+       case 0:
+               em28xx_info("\tNo audio on board.\n");
+               break;
+       case 1:
+               em28xx_info("\tAC97 audio (5 sample rates)\n");
+               break;
+       case 2:
+               if (dev->chip_id < CHIP_ID_EM2860)
+                       em28xx_info("\tI2S audio, sample rate=32k\n");
+               else
+                       em28xx_info("\tI2S audio, 3 sample rates\n");
+               break;
+       case 3:
+               if (dev->chip_id < CHIP_ID_EM2860)
+                       em28xx_info("\tI2S audio, 3 sample rates\n");
+               else
+                       em28xx_info("\tI2S audio, 5 sample rates\n");
+               break;
+       }
+
+       if (le16_to_cpu(dev_config->chip_conf) & 1 << 3)
+               em28xx_info("\tUSB Remote wakeup capable\n");
+
+       if (le16_to_cpu(dev_config->chip_conf) & 1 << 2)
+               em28xx_info("\tUSB Self power capable\n");
+
+       switch (le16_to_cpu(dev_config->chip_conf) & 0x3) {
+       case 0:
+               em28xx_info("\t500mA max power\n");
+               break;
+       case 1:
+               em28xx_info("\t400mA max power\n");
+               break;
+       case 2:
+               em28xx_info("\t300mA max power\n");
+               break;
+       case 3:
+               em28xx_info("\t200mA max power\n");
+               break;
+       }
+       em28xx_info("\tTable at offset 0x%02x, strings=0x%04x, 0x%04x, 0x%04x\n",
+                   dev_config->string_idx_table,
+                   le16_to_cpu(dev_config->string1),
+                   le16_to_cpu(dev_config->string2),
+                   le16_to_cpu(dev_config->string3));
+
+       return 0;
+
+error:
+       kfree(data);
+       return err;
+}
+
+/* ----------------------------------------------------------- */
+
+/*
+ * functionality()
+ */
+static u32 functionality(struct i2c_adapter *i2c_adap)
+{
+       struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
+
+       if ((i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX) ||
+           (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)) {
+               return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+       } else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)  {
+               return (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL) &
+                       ~I2C_FUNC_SMBUS_WRITE_BLOCK_DATA;
+       }
+
+       WARN(1, "Unknown i2c bus algorithm.\n");
+       return 0;
+}
+
+static struct i2c_algorithm em28xx_algo = {
+       .master_xfer   = em28xx_i2c_xfer,
+       .functionality = functionality,
+};
+
+static struct i2c_adapter em28xx_adap_template = {
+       .owner = THIS_MODULE,
+       .name = "em28xx",
+       .algo = &em28xx_algo,
+};
+
+static struct i2c_client em28xx_client_template = {
+       .name = "em28xx internal",
+};
+
+/* ----------------------------------------------------------- */
+
+/*
+ * i2c_devs
+ * incomplete list of known devices
+ */
+static char *i2c_devs[128] = {
+       [0x1c >> 1] = "lgdt330x",
+       [0x3e >> 1] = "remote IR sensor",
+       [0x4a >> 1] = "saa7113h",
+       [0x52 >> 1] = "drxk",
+       [0x60 >> 1] = "remote IR sensor",
+       [0x8e >> 1] = "remote IR sensor",
+       [0x86 >> 1] = "tda9887",
+       [0x80 >> 1] = "msp34xx",
+       [0x88 >> 1] = "msp34xx",
+       [0xa0 >> 1] = "eeprom",
+       [0xb0 >> 1] = "tda9874",
+       [0xb8 >> 1] = "tvp5150a",
+       [0xba >> 1] = "webcam sensor or tvp5150a",
+       [0xc0 >> 1] = "tuner (analog)",
+       [0xc2 >> 1] = "tuner (analog)",
+       [0xc4 >> 1] = "tuner (analog)",
+       [0xc6 >> 1] = "tuner (analog)",
+};
+
+/*
+ * do_i2c_scan()
+ * check i2c address range for devices
+ */
+void em28xx_do_i2c_scan(struct em28xx *dev, unsigned bus)
+{
+       u8 i2c_devicelist[128];
+       unsigned char buf;
+       int i, rc;
+
+       memset(i2c_devicelist, 0, ARRAY_SIZE(i2c_devicelist));
+
+       for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
+               dev->i2c_client[bus].addr = i;
+               rc = i2c_master_recv(&dev->i2c_client[bus], &buf, 0);
+               if (rc < 0)
+                       continue;
+               i2c_devicelist[i] = i;
+               em28xx_info("found i2c device @ 0x%x on bus %d [%s]\n",
+                           i << 1, bus, i2c_devs[i] ? i2c_devs[i] : "???");
+       }
+
+       if (bus == dev->def_i2c_bus)
+               dev->i2c_hash = em28xx_hash_mem(i2c_devicelist,
+                                               ARRAY_SIZE(i2c_devicelist), 32);
+}
+
+/*
+ * em28xx_i2c_register()
+ * register i2c bus
+ */
+int em28xx_i2c_register(struct em28xx *dev, unsigned bus,
+                       enum em28xx_i2c_algo_type algo_type)
+{
+       int retval;
+
+       BUG_ON(!dev->em28xx_write_regs || !dev->em28xx_read_reg);
+       BUG_ON(!dev->em28xx_write_regs_req || !dev->em28xx_read_reg_req);
+
+       if (bus >= NUM_I2C_BUSES)
+               return -ENODEV;
+
+       dev->i2c_adap[bus] = em28xx_adap_template;
+       dev->i2c_adap[bus].dev.parent = &dev->udev->dev;
+       strcpy(dev->i2c_adap[bus].name, dev->name);
+
+       dev->i2c_bus[bus].bus = bus;
+       dev->i2c_bus[bus].algo_type = algo_type;
+       dev->i2c_bus[bus].dev = dev;
+       dev->i2c_adap[bus].algo_data = &dev->i2c_bus[bus];
+
+       retval = i2c_add_adapter(&dev->i2c_adap[bus]);
+       if (retval < 0) {
+               em28xx_errdev("%s: i2c_add_adapter failed! retval [%d]\n",
+                             __func__, retval);
+               return retval;
+       }
+
+       dev->i2c_client[bus] = em28xx_client_template;
+       dev->i2c_client[bus].adapter = &dev->i2c_adap[bus];
+
+       /* Up to now, all eeproms are at bus 0 */
+       if (!bus) {
+               retval = em28xx_i2c_eeprom(dev, bus, &dev->eedata, &dev->eedata_len);
+               if ((retval < 0) && (retval != -ENODEV)) {
+                       em28xx_errdev("%s: em28xx_i2_eeprom failed! retval [%d]\n",
+                                     __func__, retval);
+
+                       return retval;
+               }
+       }
+
+       if (i2c_scan)
+               em28xx_do_i2c_scan(dev, bus);
+
+       return 0;
+}
+
+/*
+ * em28xx_i2c_unregister()
+ * unregister i2c_bus
+ */
+int em28xx_i2c_unregister(struct em28xx *dev, unsigned bus)
+{
+       if (bus >= NUM_I2C_BUSES)
+               return -ENODEV;
+
+       i2c_del_adapter(&dev->i2c_adap[bus]);
+       return 0;
+}