staging: kpc2000: add initial set of Daktronics drivers

These drivers have been outside of the kernel tree since the 2.x days,
and it's time to bring them into the tree so they can get properly
cleaned up.

This first dump of drivers is based on a tarball Matt gave to me, minus
an odd "dma" driver that I could not get to build at all.  I renamed a
few files, added the proper SPDX lines to it, added Kconfig entries and
tied it into the kernel build.  I also fixed up a number of initial
obvious kernel build warnings, but left the odd bitfield warning that
gcc is spitting out, as I'm not quite sure what to do about that.

There's loads of low-hanging coding style cleanups in here for people to
start attacking, as well as the more obvious logic and api cleanups as
well.

Cc: Matt Sickler <Matt.Sickler@daktronics.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 883 insertions, 0 deletions

diff --git a/drivers/staging/kpc2000/kpc_i2c/Makefile b/drivers/staging/kpc2000/kpc_i2c/Makefile
new file mode 100644
index 000000000000..73ec07ac7d39
--- /dev/null
+++ b/drivers/staging/kpc2000/kpc_i2c/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-m := kpc2000_i2c.o
+kpc2000_i2c-objs := i2c_driver.o fileops.o
diff --git a/drivers/staging/kpc2000/kpc_i2c/fileops.c b/drivers/staging/kpc2000/kpc_i2c/fileops.c
new file mode 100644
index 000000000000..e749c0994491
--- /dev/null
+++ b/drivers/staging/kpc2000/kpc_i2c/fileops.c
@@ -0,0 +1,181 @@
+// SPDX-License-Identifier: GPL-2.0+
+#if 0
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>	/* printk() */
+#include <linux/slab.h>		/* kmalloc() */
+#include <linux/fs.h>		/* everything... */
+#include <linux/errno.h>	/* error codes */
+#include <linux/types.h>	/* size_t */
+#include <linux/cdev.h>
+#include <asm/uaccess.h>	/* copy_*_user */
+
+#include "i2c_driver.h"
+
+int i2c_cdev_open(struct inode *inode, struct file *filp)
+{
+  struct i2c_device *lddev;
+  
+  if(NULL == inode) {
+    //printk(KERN_WARNING "<pl_i2c> i2c_cdev_open: inode is a NULL pointer\n");
+    DBG_PRINT(KERN_WARNING, "i2c_cdev_open: inode is a NULL pointer\n");
+    return -EINVAL;
+  }
+  if(NULL == filp) {
+    //printk(KERN_WARNING "<pl_i2c> i2c_cdev_open: filp is a NULL pointer\n");
+    DBG_PRINT(KERN_WARNING, "i2c_cdev_open: filp is a NULL pointer\n");
+    return -EINVAL;
+  }
+  
+  lddev = container_of(inode->i_cdev, struct i2c_device, cdev);
+  //printk(KERN_DEBUG "<pl_i2c> i2c_cdev_open(filp = [%p], lddev = [%p])\n", filp, lddev);
+  DBG_PRINT(KERN_DEBUG, "i2c_cdev_open(filp = [%p], lddev = [%p])\n", filp, lddev);
+  
+  filp->private_data = lddev; /* so other methods can access it */
+  
+  return 0;	/* success */
+}
+
+int i2c_cdev_close(struct inode *inode, struct file *filp)
+{
+  struct i2c_device *lddev;
+  
+  if(NULL == inode) {
+    //printk(KERN_WARNING "<pl_i2c> i2c_cdev_close: inode is a NULL pointer\n");
+    DBG_PRINT(KERN_WARNING, "i2c_cdev_close: inode is a NULL pointer\n");
+    return -EINVAL;
+  }
+  if(NULL == filp) {
+    //printk(KERN_WARNING "<pl_i2c> i2c_cdev_close: filp is a NULL pointer\n");
+    DBG_PRINT(KERN_WARNING, "i2c_cdev_close: filp is a NULL pointer\n");
+    return -EINVAL;
+  }
+  
+  lddev = filp->private_data;
+  //printk(KERN_DEBUG "<pl_i2c> i2c_cdev_close(filp = [%p], lddev = [%p])\n", filp, lddev);
+  DBG_PRINT(KERN_DEBUG, "i2c_cdev_close(filp = [%p], lddev = [%p])\n", filp, lddev);
+  
+  return 0;
+}
+
+ssize_t i2c_cdev_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos)
+{
+  size_t copy;
+  ssize_t ret = 0;
+  int err = 0;
+  u64 read_val;
+  char tmp_buf[48] = { 0 };
+  struct i2c_device *lddev = filp->private_data;
+
+  if(NULL == filp) {
+    //printk(KERN_WARNING "<pl_i2c> i2c_cdev_read: filp is a NULL pointer\n");
+    DBG_PRINT(KERN_WARNING, "i2c_cdev_read: filp is a NULL pointer\n");
+    return -EINVAL;
+  }
+  if(NULL == buf) {
+    //printk(KERN_WARNING "<pl_i2c> i2c_cdev_read: buf is a NULL pointer\n");
+    DBG_PRINT(KERN_WARNING, "i2c_cdev_read: buf is a NULL pointer\n");
+    return -EINVAL;
+  }
+  if(NULL == f_pos) {
+    //printk(KERN_WARNING "<pl_i2c> i2c_cdev_read: f_pos is a NULL pointer\n");
+    DBG_PRINT(KERN_WARNING, "i2c_cdev_read: f_pos is a NULL pointer\n");
+    return -EINVAL;
+  }
+
+  if(count < sizeof(tmp_buf)) {
+    //printk(KERN_INFO "<pl_i2c> i2c_cdev_read: buffer is too small (count = %d, should be at least %d bytes)\n", (int)count, (int)sizeof(tmp_buf));
+    DBG_PRINT(KERN_INFO, "i2c_cdev_read: buffer is too small (count = %d, should be at least %d bytes)\n", (int)count, (int)sizeof(tmp_buf));
+    return -EINVAL;
+  }
+  if(((*f_pos * 8) + lddev->pldev->resource[0].start) > lddev->pldev->resource[0].end) {
+    //printk(KERN_INFO "<pl_i2c> i2c_cdev_read: bad read addr %016llx\n", (*f_pos * 8) + lddev->pldev->resource[0].start);
+    DBG_PRINT(KERN_INFO, "i2c_cdev_read: bad read addr %016llx\n", (*f_pos * 8) + lddev->pldev->resource[0].start);
+    //printk(KERN_INFO "<pl_i2c> i2c_cdev_read: addr end %016llx\n", lddev->pldev->resource[0].end);
+    DBG_PRINT(KERN_INFO, "i2c_cdev_read: addr end %016llx\n", lddev->pldev->resource[0].end);
+    //printk(KERN_INFO "<pl_i2c> i2c_cdev_read: EOF reached\n");
+    DBG_PRINT(KERN_INFO, "i2c_cdev_read: EOF reached\n");
+    return 0;
+  }
+
+  down_read(&lddev->rw_sem);
+  
+  read_val = *(lddev->regs + *f_pos);
+  copy = clamp_t(size_t, count, 1, sizeof(tmp_buf));
+  copy = scnprintf(tmp_buf, copy, "reg: 0x%x val: 0x%llx\n", (unsigned int)*f_pos, read_val);
+  err = copy_to_user(buf, tmp_buf, copy);
+  if(err) {
+    //printk(KERN_INFO "<pl_i2c> i2c_cdev_read: could not copy to user (err = %d)\n", err);
+    DBG_PRINT(KERN_INFO, "i2c_cdev_read: could not copy to user (err = %d)\n", err);
+    return -EINVAL;
+  }
+
+  ret = (ssize_t)copy;
+  (*f_pos)++;
+  
+  up_read(&lddev->rw_sem);
+  
+  return ret;
+}
+
+ssize_t i2c_cdev_write(struct file *filp, const char __user *buf, size_t count, loff_t *f_pos)
+{
+  u8 reg;
+  u8 val;
+  char tmp[8] = { 0 };
+  struct i2c_device *lddev = filp->private_data;
+
+  if(NULL == filp) {
+    //printk(KERN_WARNING "<pl_i2c> i2c_cdev_write: filp is a NULL pointer\n");
+    DBG_PRINT(KERN_WARNING, "i2c_cdev_write: filp is a NULL pointer\n");
+    return -EINVAL;
+  }
+  if(NULL == buf) {
+    //printk(KERN_WARNING "<pl_i2c> i2c_cdev_write: buf is a NULL pointer\n");
+    DBG_PRINT(KERN_WARNING, "i2c_cdev_write: buf is a NULL pointer\n");
+    return -EINVAL;
+  }
+  if(NULL == f_pos) {
+    //printk(KERN_WARNING "<pl_i2c> i2c_cdev_write: f_pos is a NULL pointer\n");
+    DBG_PRINT(KERN_WARNING, "i2c_cdev_write: f_pos is a NULL pointer\n");
+    return -EINVAL;
+  }
+
+  //printk(KERN_DEBUG "<pl_i2c> i2c_cdev_write(filp = [%p], lddev = [%p])\n", filp, lddev);
+  DBG_PRINT(KERN_DEBUG, "i2c_cdev_write(filp = [%p], lddev = [%p])\n", filp, lddev);
+
+  down_write(&lddev->rw_sem);
+
+  if(count >= 2) {
+    if(copy_from_user(tmp, buf, 2)) {
+      return -EFAULT;
+    }
+    
+    reg = tmp[0] - '0';
+    val = tmp[1] - '0';
+
+    //printk(KERN_DEBUG "  reg = %d  val = %d\n", reg, val);
+    DBG_PRINT(KERN_DEBUG, "  reg = %d  val = %d\n", reg, val);
+
+    if(reg >= 0 && reg < 16) {
+      //printk(KERN_DEBUG "  Writing 0x%x to %p\n", val, lddev->regs + reg);
+      DBG_PRINT(KERN_DEBUG, "  Writing 0x%x to %p\n", val, lddev->regs + reg);
+      *(lddev->regs + reg) = val;
+    }
+  }
+
+  (*f_pos)++;
+
+  up_write(&lddev->rw_sem);
+
+  return count;
+}
+
+struct file_operations i2c_fops = {
+  .owner		= THIS_MODULE,
+  .open		= i2c_cdev_open,
+  .release	= i2c_cdev_close,
+  .read		= i2c_cdev_read,
+  .write		= i2c_cdev_write,
+};
+#endif
diff --git a/drivers/staging/kpc2000/kpc_i2c/i2c_driver.c b/drivers/staging/kpc2000/kpc_i2c/i2c_driver.c
new file mode 100644
index 000000000000..6bb6ad4abe87
--- /dev/null
+++ b/drivers/staging/kpc2000/kpc_i2c/i2c_driver.c
@@ -0,0 +1,698 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*  Copyright (c) 2014-2018  Daktronics,
+                             Matt Sickler <matt.sickler@daktronics.com>,
+                             Jordon Hofer <jordon.hofer@daktronics.com>
+    Adapted i2c-i801.c for use with Kadoka hardware.
+    Copyright (c) 1998 - 2002  Frodo Looijaard <frodol@dds.nl>,
+    Philip Edelbrock <phil@netroedge.com>, and Mark D. Studebaker
+    <mdsxyz123@yahoo.com>
+    Copyright (C) 2007 - 2012  Jean Delvare <khali@linux-fr.org>
+    Copyright (C) 2010         Intel Corporation,
+                               David Woodhouse <dwmw2@infradead.org>
+*/
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <asm/io.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/fs.h>
+#include <linux/rwsem.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include "../kpc.h"
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Matt.Sickler@Daktronics.com");
+MODULE_SOFTDEP("pre: i2c-dev");
+
+struct i2c_device {
+    unsigned long           smba;
+    struct i2c_adapter      adapter;
+    struct platform_device *pldev;
+    struct rw_semaphore     rw_sem;
+    unsigned int            features;
+};
+
+/*****************************
+ *** Part 1 - i2c Handlers ***
+ *****************************/
+
+#define REG_SIZE 8
+
+/* I801 SMBus address offsets */
+#define SMBHSTSTS(p)    ((0  * REG_SIZE) + (p)->smba)
+#define SMBHSTCNT(p)    ((2  * REG_SIZE) + (p)->smba)
+#define SMBHSTCMD(p)    ((3  * REG_SIZE) + (p)->smba)
+#define SMBHSTADD(p)    ((4  * REG_SIZE) + (p)->smba)
+#define SMBHSTDAT0(p)   ((5  * REG_SIZE) + (p)->smba)
+#define SMBHSTDAT1(p)   ((6  * REG_SIZE) + (p)->smba)
+#define SMBBLKDAT(p)    ((7  * REG_SIZE) + (p)->smba)
+#define SMBPEC(p)       ((8  * REG_SIZE) + (p)->smba)   /* ICH3 and later */
+#define SMBAUXSTS(p)    ((12 * REG_SIZE) + (p)->smba)   /* ICH4 and later */
+#define SMBAUXCTL(p)    ((13 * REG_SIZE) + (p)->smba)   /* ICH4 and later */
+
+/* PCI Address Constants */
+#define SMBBAR      4
+#define SMBHSTCFG   0x040
+
+/* Host configuration bits for SMBHSTCFG */
+#define SMBHSTCFG_HST_EN        1
+#define SMBHSTCFG_SMB_SMI_EN    2
+#define SMBHSTCFG_I2C_EN        4
+
+/* Auxiliary control register bits, ICH4+ only */
+#define SMBAUXCTL_CRC       1
+#define SMBAUXCTL_E32B      2
+
+/* kill bit for SMBHSTCNT */
+#define SMBHSTCNT_KILL      2
+
+/* Other settings */
+#define MAX_RETRIES         400
+#define ENABLE_INT9         0       /* set to 0x01 to enable - untested */
+
+/* I801 command constants */
+#define I801_QUICK              0x00
+#define I801_BYTE               0x04
+#define I801_BYTE_DATA          0x08
+#define I801_WORD_DATA          0x0C
+#define I801_PROC_CALL          0x10    /* unimplemented */
+#define I801_BLOCK_DATA         0x14
+#define I801_I2C_BLOCK_DATA     0x18    /* ICH5 and later */
+#define I801_BLOCK_LAST         0x34
+#define I801_I2C_BLOCK_LAST     0x38    /* ICH5 and later */
+#define I801_START              0x40
+#define I801_PEC_EN             0x80    /* ICH3 and later */
+
+/* I801 Hosts Status register bits */
+#define SMBHSTSTS_BYTE_DONE     0x80
+#define SMBHSTSTS_INUSE_STS     0x40
+#define SMBHSTSTS_SMBALERT_STS  0x20
+#define SMBHSTSTS_FAILED        0x10
+#define SMBHSTSTS_BUS_ERR       0x08
+#define SMBHSTSTS_DEV_ERR       0x04
+#define SMBHSTSTS_INTR          0x02
+#define SMBHSTSTS_HOST_BUSY     0x01
+
+#define STATUS_FLAGS        (SMBHSTSTS_BYTE_DONE | SMBHSTSTS_FAILED | SMBHSTSTS_BUS_ERR | SMBHSTSTS_DEV_ERR | SMBHSTSTS_INTR)
+
+/* Older devices have their ID defined in <linux/pci_ids.h> */
+#define PCI_DEVICE_ID_INTEL_COUGARPOINT_SMBUS       0x1c22
+#define PCI_DEVICE_ID_INTEL_PATSBURG_SMBUS          0x1d22
+/* Patsburg also has three 'Integrated Device Function' SMBus controllers */
+#define PCI_DEVICE_ID_INTEL_PATSBURG_SMBUS_IDF0     0x1d70
+#define PCI_DEVICE_ID_INTEL_PATSBURG_SMBUS_IDF1     0x1d71
+#define PCI_DEVICE_ID_INTEL_PATSBURG_SMBUS_IDF2     0x1d72
+#define PCI_DEVICE_ID_INTEL_PANTHERPOINT_SMBUS      0x1e22
+#define PCI_DEVICE_ID_INTEL_DH89XXCC_SMBUS          0x2330
+#define PCI_DEVICE_ID_INTEL_5_3400_SERIES_SMBUS     0x3b30
+#define PCI_DEVICE_ID_INTEL_LYNXPOINT_SMBUS         0x8c22
+#define PCI_DEVICE_ID_INTEL_LYNXPOINT_LP_SMBUS      0x9c22
+
+
+#define FEATURE_SMBUS_PEC       (1 << 0)
+#define FEATURE_BLOCK_BUFFER    (1 << 1)
+#define FEATURE_BLOCK_PROC      (1 << 2)
+#define FEATURE_I2C_BLOCK_READ  (1 << 3)
+/* Not really a feature, but it's convenient to handle it as such */
+#define FEATURE_IDF             (1 << 15)
+
+static unsigned int disable_features;
+module_param(disable_features, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(disable_features, "Disable selected driver features");
+
+// FIXME!
+#undef inb_p
+#define inb_p(a) readq((void*)a)
+#undef outb_p
+#define outb_p(d,a) writeq(d,(void*)a)
+
+/* Make sure the SMBus host is ready to start transmitting.
+   Return 0 if it is, -EBUSY if it is not. */
+static int i801_check_pre(struct i2c_device *priv)
+{
+    int status;
+    
+    dev_dbg(&priv->adapter.dev, "i801_check_pre\n");
+    
+    status = inb_p(SMBHSTSTS(priv));
+    if (status & SMBHSTSTS_HOST_BUSY) {
+        dev_err(&priv->adapter.dev, "SMBus is busy, can't use it! (status=%x)\n", status);
+        return -EBUSY;
+    }
+    
+    status &= STATUS_FLAGS;
+    if (status) {
+        //dev_dbg(&priv->adapter.dev, "Clearing status flags (%02x)\n", status);
+        outb_p(status, SMBHSTSTS(priv));
+        status = inb_p(SMBHSTSTS(priv)) & STATUS_FLAGS;
+        if (status) {
+          dev_err(&priv->adapter.dev, "Failed clearing status flags (%02x)\n", status);
+          return -EBUSY;
+        }
+    }
+    return 0;
+}
+
+/* Convert the status register to an error code, and clear it. */
+static int i801_check_post(struct i2c_device *priv, int status, int timeout)
+{
+    int result = 0;
+    
+    dev_dbg(&priv->adapter.dev, "i801_check_post\n");
+    
+    /* If the SMBus is still busy, we give up */
+    if (timeout) {
+        dev_err(&priv->adapter.dev, "Transaction timeout\n");
+        /* try to stop the current command */
+        dev_dbg(&priv->adapter.dev, "Terminating the current operation\n");
+        outb_p(inb_p(SMBHSTCNT(priv)) | SMBHSTCNT_KILL, SMBHSTCNT(priv));
+        usleep_range(1000, 2000);
+        outb_p(inb_p(SMBHSTCNT(priv)) & (~SMBHSTCNT_KILL), SMBHSTCNT(priv));
+        
+        /* Check if it worked */
+        status = inb_p(SMBHSTSTS(priv));
+        if ((status & SMBHSTSTS_HOST_BUSY) || !(status & SMBHSTSTS_FAILED)) {
+            dev_err(&priv->adapter.dev, "Failed terminating the transaction\n");
+        }
+        outb_p(STATUS_FLAGS, SMBHSTSTS(priv));
+        return -ETIMEDOUT;
+    }
+    
+    if (status & SMBHSTSTS_FAILED) {
+        result = -EIO;
+        dev_err(&priv->adapter.dev, "Transaction failed\n");
+    }
+    if (status & SMBHSTSTS_DEV_ERR) {
+        result = -ENXIO;
+        dev_dbg(&priv->adapter.dev, "No response\n");
+    }
+    if (status & SMBHSTSTS_BUS_ERR) {
+        result = -EAGAIN;
+        dev_dbg(&priv->adapter.dev, "Lost arbitration\n");
+    }
+    
+    if (result) {
+        /* Clear error flags */
+        outb_p(status & STATUS_FLAGS, SMBHSTSTS(priv));
+        status = inb_p(SMBHSTSTS(priv)) & STATUS_FLAGS;
+        if (status) {
+            dev_warn(&priv->adapter.dev, "Failed clearing status flags at end of transaction (%02x)\n", status);
+        }
+    }
+    
+    return result;
+}
+
+static int i801_transaction(struct i2c_device *priv, int xact)
+{
+    int status;
+    int result;
+    int timeout = 0;
+    
+    dev_dbg(&priv->adapter.dev, "i801_transaction\n");
+    
+    result = i801_check_pre(priv);
+    if (result < 0) {
+        return result;
+    }
+    /* the current contents of SMBHSTCNT can be overwritten, since PEC,
+    * INTREN, SMBSCMD are passed in xact */
+    outb_p(xact | I801_START, SMBHSTCNT(priv));
+    
+    /* We will always wait for a fraction of a second! */
+    do {
+        usleep_range(250, 500);
+        status = inb_p(SMBHSTSTS(priv));
+    } while ((status & SMBHSTSTS_HOST_BUSY) && (timeout++ < MAX_RETRIES));
+    
+    result = i801_check_post(priv, status, timeout > MAX_RETRIES);
+    if (result < 0) {
+        return result;
+    }
+    
+    outb_p(SMBHSTSTS_INTR, SMBHSTSTS(priv));
+    return 0;
+}
+
+/* wait for INTR bit as advised by Intel */
+static void i801_wait_hwpec(struct i2c_device *priv)
+{
+    int timeout = 0;
+    int status;
+    
+    dev_dbg(&priv->adapter.dev, "i801_wait_hwpec\n");
+    
+    do {
+        usleep_range(250, 500);
+        status = inb_p(SMBHSTSTS(priv));
+    } while ((!(status & SMBHSTSTS_INTR)) && (timeout++ < MAX_RETRIES));
+    
+    if (timeout > MAX_RETRIES) {
+        dev_dbg(&priv->adapter.dev, "PEC Timeout!\n");
+    }
+    
+    outb_p(status, SMBHSTSTS(priv));
+}
+
+static int i801_block_transaction_by_block(struct i2c_device *priv, union i2c_smbus_data *data, char read_write, int hwpec)
+{
+    int i, len;
+    int status;
+    
+    dev_dbg(&priv->adapter.dev, "i801_block_transaction_by_block\n");
+    
+    inb_p(SMBHSTCNT(priv)); /* reset the data buffer index */
+    
+    /* Use 32-byte buffer to process this transaction */
+    if (read_write == I2C_SMBUS_WRITE) {
+        len = data->block[0];
+        outb_p(len, SMBHSTDAT0(priv));
+        for (i = 0; i < len; i++) {
+            outb_p(data->block[i+1], SMBBLKDAT(priv));
+        }
+    }
+    
+    status = i801_transaction(priv, I801_BLOCK_DATA | ENABLE_INT9 | I801_PEC_EN * hwpec);
+    if (status) {
+        return status;
+    }
+
+    if (read_write == I2C_SMBUS_READ) {
+        len = inb_p(SMBHSTDAT0(priv));
+        if (len < 1 || len > I2C_SMBUS_BLOCK_MAX) {
+            return -EPROTO;
+        }
+        
+        data->block[0] = len;
+        for (i = 0; i < len; i++) {
+            data->block[i + 1] = inb_p(SMBBLKDAT(priv));
+        }
+    }
+    return 0;
+}
+
+static int i801_block_transaction_byte_by_byte(struct i2c_device *priv, union i2c_smbus_data *data, char read_write, int command, int hwpec)
+{
+    int i, len;
+    int smbcmd;
+    int status;
+    int result;
+    int timeout;
+    
+    dev_dbg(&priv->adapter.dev, "i801_block_transaction_byte_by_byte\n");
+    
+    result = i801_check_pre(priv);
+    if (result < 0) {
+        return result;
+    }
+    
+    len = data->block[0];
+    
+    if (read_write == I2C_SMBUS_WRITE) {
+        outb_p(len, SMBHSTDAT0(priv));
+        outb_p(data->block[1], SMBBLKDAT(priv));
+    }
+    
+    for (i = 1; i <= len; i++) {
+        if (i == len && read_write == I2C_SMBUS_READ) {
+            if (command == I2C_SMBUS_I2C_BLOCK_DATA) {
+                smbcmd = I801_I2C_BLOCK_LAST;
+            } else {
+                smbcmd = I801_BLOCK_LAST;
+            }
+        } else {
+            if (command == I2C_SMBUS_I2C_BLOCK_DATA && read_write == I2C_SMBUS_READ) {
+                smbcmd = I801_I2C_BLOCK_DATA;
+            } else {
+                smbcmd = I801_BLOCK_DATA;
+            }
+        }
+        outb_p(smbcmd | ENABLE_INT9, SMBHSTCNT(priv));
+        
+        if (i == 1) {
+            outb_p(inb(SMBHSTCNT(priv)) | I801_START, SMBHSTCNT(priv));
+        }
+        /* We will always wait for a fraction of a second! */
+        timeout = 0;
+        do {
+            usleep_range(250, 500);
+            status = inb_p(SMBHSTSTS(priv));
+        } while ((!(status & SMBHSTSTS_BYTE_DONE)) && (timeout++ < MAX_RETRIES));
+        
+        result = i801_check_post(priv, status, timeout > MAX_RETRIES);
+        if (result < 0) {
+            return result;
+        }
+        if (i == 1 && read_write == I2C_SMBUS_READ && command != I2C_SMBUS_I2C_BLOCK_DATA) {
+            len = inb_p(SMBHSTDAT0(priv));
+            if (len < 1 || len > I2C_SMBUS_BLOCK_MAX) {
+                dev_err(&priv->adapter.dev, "Illegal SMBus block read size %d\n", len);
+                /* Recover */
+                while (inb_p(SMBHSTSTS(priv)) & SMBHSTSTS_HOST_BUSY) {
+                    outb_p(SMBHSTSTS_BYTE_DONE, SMBHSTSTS(priv));
+                }
+                outb_p(SMBHSTSTS_INTR, SMBHSTSTS(priv));
+                return -EPROTO;
+            }
+            data->block[0] = len;
+        }
+        
+        /* Retrieve/store value in SMBBLKDAT */
+        if (read_write == I2C_SMBUS_READ) {
+            data->block[i] = inb_p(SMBBLKDAT(priv));
+        }
+        if (read_write == I2C_SMBUS_WRITE && i+1 <= len) {
+            outb_p(data->block[i+1], SMBBLKDAT(priv));
+        }
+        /* signals SMBBLKDAT ready */
+        outb_p(SMBHSTSTS_BYTE_DONE | SMBHSTSTS_INTR, SMBHSTSTS(priv));
+    }
+    
+    return 0;
+}
+
+static int i801_set_block_buffer_mode(struct i2c_device *priv)
+{
+    dev_dbg(&priv->adapter.dev, "i801_set_block_buffer_mode\n");
+    
+    outb_p(inb_p(SMBAUXCTL(priv)) | SMBAUXCTL_E32B, SMBAUXCTL(priv));
+    if ((inb_p(SMBAUXCTL(priv)) & SMBAUXCTL_E32B) == 0) {
+        return -EIO;
+    }
+    return 0;
+}
+
+/* Block transaction function */
+static int i801_block_transaction(struct i2c_device *priv, union i2c_smbus_data *data, char read_write, int command, int hwpec)
+{
+    int result = 0;
+    //unsigned char hostc;
+    
+    dev_dbg(&priv->adapter.dev, "i801_block_transaction\n");
+    
+    if (command == I2C_SMBUS_I2C_BLOCK_DATA) {
+        if (read_write == I2C_SMBUS_WRITE) {
+            /* set I2C_EN bit in configuration register */
+            //TODO: Figure out the right thing to do here...
+            //pci_read_config_byte(priv->pci_dev, SMBHSTCFG, &hostc);
+            //pci_write_config_byte(priv->pci_dev, SMBHSTCFG, hostc | SMBHSTCFG_I2C_EN);
+        } else if (!(priv->features & FEATURE_I2C_BLOCK_READ)) {
+            dev_err(&priv->adapter.dev, "I2C block read is unsupported!\n");
+            return -EOPNOTSUPP;
+        }
+    }
+    
+    if (read_write == I2C_SMBUS_WRITE || command == I2C_SMBUS_I2C_BLOCK_DATA) {
+        if (data->block[0] < 1) {
+            data->block[0] = 1;
+        }
+        if (data->block[0] > I2C_SMBUS_BLOCK_MAX) {
+            data->block[0] = I2C_SMBUS_BLOCK_MAX;
+        }
+    } else {
+        data->block[0] = 32;	/* max for SMBus block reads */
+    }
+    
+    /* Experience has shown that the block buffer can only be used for
+        SMBus (not I2C) block transactions, even though the datasheet
+        doesn't mention this limitation. */
+    if ((priv->features & FEATURE_BLOCK_BUFFER) && command != I2C_SMBUS_I2C_BLOCK_DATA && i801_set_block_buffer_mode(priv) == 0) {
+        result = i801_block_transaction_by_block(priv, data, read_write, hwpec);
+    } else {
+        result = i801_block_transaction_byte_by_byte(priv, data, read_write, command, hwpec);
+    }  
+    if (result == 0 && hwpec) {
+        i801_wait_hwpec(priv);
+    }
+    if (command == I2C_SMBUS_I2C_BLOCK_DATA && read_write == I2C_SMBUS_WRITE) {
+        /* restore saved configuration register value */
+        //TODO: Figure out the right thing to do here...
+        //pci_write_config_byte(priv->pci_dev, SMBHSTCFG, hostc);
+    }
+    return result;
+}
+
+/* Return negative errno on error. */
+static s32 i801_access(struct i2c_adapter *adap, u16 addr, unsigned short flags, char read_write, u8 command, int size, union i2c_smbus_data *data)
+{
+    int hwpec;
+    int block = 0;
+    int ret, xact = 0;
+    struct i2c_device *priv = i2c_get_adapdata(adap);
+    
+    dev_dbg(&priv->adapter.dev, "i801_access (addr=%0d)  flags=%x  read_write=%x  command=%x  size=%x",
+      addr, flags, read_write, command, size );
+    
+    hwpec = (priv->features & FEATURE_SMBUS_PEC) && (flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK && size != I2C_SMBUS_I2C_BLOCK_DATA;
+    
+    switch (size) {
+        case I2C_SMBUS_QUICK:
+            dev_dbg(&priv->adapter.dev, "  [acc] SMBUS_QUICK\n");
+            outb_p(((addr & 0x7f) << 1) | (read_write & 0x01), SMBHSTADD(priv));
+            xact = I801_QUICK;
+            break;
+        case I2C_SMBUS_BYTE:
+            dev_dbg(&priv->adapter.dev, "  [acc] SMBUS_BYTE\n");
+            
+            outb_p(((addr & 0x7f) << 1) | (read_write & 0x01), SMBHSTADD(priv));
+            if (read_write == I2C_SMBUS_WRITE) {
+                outb_p(command, SMBHSTCMD(priv));
+            }
+            xact = I801_BYTE;
+            break;
+        case I2C_SMBUS_BYTE_DATA:
+            dev_dbg(&priv->adapter.dev, "  [acc] SMBUS_BYTE_DATA\n");
+            outb_p(((addr & 0x7f) << 1) | (read_write & 0x01), SMBHSTADD(priv));
+            outb_p(command, SMBHSTCMD(priv));
+            if (read_write == I2C_SMBUS_WRITE) {
+                outb_p(data->byte, SMBHSTDAT0(priv));
+            }
+            xact = I801_BYTE_DATA;
+            break;
+        case I2C_SMBUS_WORD_DATA:
+            dev_dbg(&priv->adapter.dev, "  [acc] SMBUS_WORD_DATA\n");
+            outb_p(((addr & 0x7f) << 1) | (read_write & 0x01), SMBHSTADD(priv));
+            outb_p(command, SMBHSTCMD(priv));
+            if (read_write == I2C_SMBUS_WRITE) {
+                outb_p(data->word & 0xff, SMBHSTDAT0(priv));
+                outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1(priv));
+            }
+            xact = I801_WORD_DATA;
+            break;
+        case I2C_SMBUS_BLOCK_DATA:
+            dev_dbg(&priv->adapter.dev, "  [acc] SMBUS_BLOCK_DATA\n");
+            outb_p(((addr & 0x7f) << 1) | (read_write & 0x01), SMBHSTADD(priv));
+            outb_p(command, SMBHSTCMD(priv));
+            block = 1;
+            break;
+        case I2C_SMBUS_I2C_BLOCK_DATA:
+            dev_dbg(&priv->adapter.dev, "  [acc] SMBUS_I2C_BLOCK_DATA\n");
+            /* NB: page 240 of ICH5 datasheet shows that the R/#W
+             * bit should be cleared here, even when reading */
+            outb_p((addr & 0x7f) << 1, SMBHSTADD(priv));
+            if (read_write == I2C_SMBUS_READ) {
+                /* NB: page 240 of ICH5 datasheet also shows
+                 * that DATA1 is the cmd field when reading */
+                outb_p(command, SMBHSTDAT1(priv));
+            } else {
+                outb_p(command, SMBHSTCMD(priv));
+            }
+            block = 1;
+            break;
+        default:
+            dev_dbg(&priv->adapter.dev, "  [acc] Unsupported transaction %d\n", size);
+            return -EOPNOTSUPP;
+    }
+    
+    if (hwpec) { /* enable/disable hardware PEC */
+        dev_dbg(&priv->adapter.dev, "  [acc] hwpec: yes\n");
+        outb_p(inb_p(SMBAUXCTL(priv)) | SMBAUXCTL_CRC, SMBAUXCTL(priv));
+    } else {
+        dev_dbg(&priv->adapter.dev, "  [acc] hwpec: no\n");
+        outb_p(inb_p(SMBAUXCTL(priv)) & (~SMBAUXCTL_CRC), SMBAUXCTL(priv));
+    }
+    
+    if (block) {
+        //ret = 0;
+        dev_dbg(&priv->adapter.dev, "  [acc] block: yes\n");
+        ret = i801_block_transaction(priv, data, read_write, size, hwpec);
+    } else {
+        dev_dbg(&priv->adapter.dev, "  [acc] block: no\n");
+        ret = i801_transaction(priv, xact | ENABLE_INT9);
+    }
+    
+    /* Some BIOSes don't like it when PEC is enabled at reboot or resume
+       time, so we forcibly disable it after every transaction. Turn off
+       E32B for the same reason. */
+    if (hwpec || block) {
+        dev_dbg(&priv->adapter.dev, "  [acc] hwpec || block\n");
+        outb_p(inb_p(SMBAUXCTL(priv)) & ~(SMBAUXCTL_CRC | SMBAUXCTL_E32B), SMBAUXCTL(priv));
+    }
+    if (block) {
+        dev_dbg(&priv->adapter.dev, "  [acc] block\n");
+        return ret;
+    }
+    if (ret) {
+        dev_dbg(&priv->adapter.dev, "  [acc] ret %d\n", ret);
+        return ret;
+    }
+    if ((read_write == I2C_SMBUS_WRITE) || (xact == I801_QUICK)) {
+        dev_dbg(&priv->adapter.dev, "  [acc] I2C_SMBUS_WRITE || I801_QUICK  -> ret 0\n");
+        return 0;
+    }
+    
+    switch (xact & 0x7f) {
+        case I801_BYTE:  /* Result put in SMBHSTDAT0 */
+        case I801_BYTE_DATA:
+            dev_dbg(&priv->adapter.dev, "  [acc] I801_BYTE or I801_BYTE_DATA\n");
+            data->byte = inb_p(SMBHSTDAT0(priv));
+            break;
+        case I801_WORD_DATA:
+            dev_dbg(&priv->adapter.dev, "  [acc] I801_WORD_DATA\n");
+            data->word = inb_p(SMBHSTDAT0(priv)) + (inb_p(SMBHSTDAT1(priv)) << 8);
+            break;
+    }
+    return 0;
+}
+
+
+
+static u32 i801_func(struct i2c_adapter *adapter)
+{
+    struct i2c_device *priv = i2c_get_adapdata(adapter);
+    
+    /* original settings
+    u32 f = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
+      I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
+      I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_WRITE_I2C_BLOCK |
+      ((priv->features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) |
+      ((priv->features & FEATURE_I2C_BLOCK_READ) ?
+       I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0);
+     */
+    
+    // http://lxr.free-electrons.com/source/include/uapi/linux/i2c.h#L85
+    
+    u32 f = 
+        I2C_FUNC_I2C                     | /* 0x00000001 (I enabled this one) */
+        !I2C_FUNC_10BIT_ADDR             | /* 0x00000002 */
+        !I2C_FUNC_PROTOCOL_MANGLING      | /* 0x00000004 */
+        ((priv->features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) | /* 0x00000008 */
+        !I2C_FUNC_SMBUS_BLOCK_PROC_CALL  | /* 0x00008000 */
+        I2C_FUNC_SMBUS_QUICK             | /* 0x00010000 */
+        !I2C_FUNC_SMBUS_READ_BYTE        | /* 0x00020000 */
+        !I2C_FUNC_SMBUS_WRITE_BYTE       | /* 0x00040000 */
+        !I2C_FUNC_SMBUS_READ_BYTE_DATA   | /* 0x00080000 */
+        !I2C_FUNC_SMBUS_WRITE_BYTE_DATA  | /* 0x00100000 */
+        !I2C_FUNC_SMBUS_READ_WORD_DATA   | /* 0x00200000 */
+        !I2C_FUNC_SMBUS_WRITE_WORD_DATA  | /* 0x00400000 */
+        !I2C_FUNC_SMBUS_PROC_CALL        | /* 0x00800000 */
+        !I2C_FUNC_SMBUS_READ_BLOCK_DATA  | /* 0x01000000 */
+        !I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | /* 0x02000000 */
+        ((priv->features & FEATURE_I2C_BLOCK_READ) ? I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0) | /* 0x04000000 */
+        I2C_FUNC_SMBUS_WRITE_I2C_BLOCK   | /* 0x08000000 */
+        
+        I2C_FUNC_SMBUS_BYTE              | /* _READ_BYTE  _WRITE_BYTE */
+        I2C_FUNC_SMBUS_BYTE_DATA         | /* _READ_BYTE_DATA  _WRITE_BYTE_DATA */
+        I2C_FUNC_SMBUS_WORD_DATA         | /* _READ_WORD_DATA  _WRITE_WORD_DATA */
+        I2C_FUNC_SMBUS_BLOCK_DATA        | /* _READ_BLOCK_DATA  _WRITE_BLOCK_DATA */
+        !I2C_FUNC_SMBUS_I2C_BLOCK        | /* _READ_I2C_BLOCK  _WRITE_I2C_BLOCK */
+        !I2C_FUNC_SMBUS_EMUL;              /* _QUICK  _BYTE  _BYTE_DATA  _WORD_DATA  _PROC_CALL  _WRITE_BLOCK_DATA  _I2C_BLOCK _PEC */
+    return f;
+}
+
+static const struct i2c_algorithm smbus_algorithm = {
+    .smbus_xfer     = i801_access,
+    .functionality  = i801_func,
+};
+
+
+
+/********************************
+ *** Part 2 - Driver Handlers ***
+ ********************************/
+int pi2c_probe(struct platform_device *pldev)
+{
+    int err;
+    struct i2c_device *priv;
+    struct resource *res;
+    
+    dev_dbg(&pldev->dev, "pi2c_probe(pldev = %p '%s')\n", pldev, pldev->name);
+    
+    priv = kzalloc(sizeof(struct i2c_device), GFP_KERNEL);
+    if (!priv) {
+        return -ENOMEM;
+    }
+    
+    i2c_set_adapdata(&priv->adapter, priv);
+    priv->adapter.owner = THIS_MODULE;
+    priv->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
+    priv->adapter.algo = &smbus_algorithm;
+    
+    res = platform_get_resource(pldev, IORESOURCE_MEM, 0);
+    priv->smba = (unsigned long)ioremap_nocache(res->start, res->end - res->start);
+    
+    priv->pldev = pldev;
+    pldev->dev.platform_data = priv;
+    
+    priv->features |= FEATURE_IDF;
+    priv->features |= FEATURE_I2C_BLOCK_READ;
+    priv->features |= FEATURE_SMBUS_PEC;
+    priv->features |= FEATURE_BLOCK_BUFFER;
+    
+    //init_MUTEX(&lddata->sem);
+    init_rwsem(&priv->rw_sem);
+    
+    /* set up the sysfs linkage to our parent device */
+    priv->adapter.dev.parent = &pldev->dev;
+    
+    /* Retry up to 3 times on lost arbitration */
+    priv->adapter.retries = 3;
+    
+    //snprintf(priv->adapter.name, sizeof(priv->adapter.name), "Fake SMBus I801 adapter at %04lx", priv->smba);
+    snprintf(priv->adapter.name, sizeof(priv->adapter.name), "Fake SMBus I801 adapter");
+    
+    err = i2c_add_adapter(&priv->adapter);
+    if (err) {
+        dev_err(&priv->adapter.dev, "Failed to add SMBus adapter\n");
+        return err;
+    }
+    
+    return 0;
+}
+
+int pi2c_remove(struct platform_device *pldev)
+{
+    struct i2c_device *lddev;
+    dev_dbg(&pldev->dev, "pi2c_remove(pldev = %p '%s')\n", pldev, pldev->name);
+    
+    lddev = (struct i2c_device *)pldev->dev.platform_data;
+    
+    i2c_del_adapter(&lddev->adapter);
+    
+    //TODO: Figure out the right thing to do here...
+    //pci_write_config_byte(dev, SMBHSTCFG, priv->original_hstcfg);
+    //pci_release_region(dev, SMBBAR);
+    //pci_set_drvdata(dev, NULL);
+    
+    //cdev_del(&lddev->cdev);
+    if(lddev != 0) {
+        kfree(lddev);
+        pldev->dev.platform_data = 0;
+    }
+    
+    return 0;
+}
+
+struct platform_driver i2c_plat_driver_i = {
+    .probe      = pi2c_probe,
+    .remove     = pi2c_remove,
+    .driver     = {
+        .name   = KP_DRIVER_NAME_I2C,
+        .owner  = THIS_MODULE,
+    },
+};
+
+module_platform_driver(i2c_plat_driver_i);