1 files changed, 347 insertions, 0 deletions

diff --git a/drivers/sbus/char/vfc_i2c.c b/drivers/sbus/char/vfc_i2c.c
new file mode 100644
index 000000000000..95e3cebf792c
--- /dev/null
+++ b/drivers/sbus/char/vfc_i2c.c
@@ -0,0 +1,347 @@
+/*
+ * drivers/sbus/char/vfc_i2c.c
+ *
+ * Driver for the Videopix Frame Grabber.
+ * 
+ * Functions that support the Phillips i2c(I squared C) bus on the vfc
+ *  Documentation for the Phillips I2C bus can be found on the 
+ *  phillips home page
+ *
+ * Copyright (C) 1996 Manish Vachharajani (mvachhar@noc.rutgers.edu)
+ *
+ */
+
+/* NOTE: It seems to me that the documentation regarding the
+pcd8584t/pcf8584 does not show the correct way to address the i2c bus.
+Based on the information on the I2C bus itself and the remainder of
+the Phillips docs the following algorithims apper to be correct.  I am
+fairly certain that the flowcharts in the phillips docs are wrong. */
+
+
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/delay.h>
+#include <asm/openprom.h>
+#include <asm/oplib.h>
+#include <asm/io.h>
+#include <asm/system.h>
+#include <asm/sbus.h>
+
+#if 0 
+#define VFC_I2C_DEBUG
+#endif
+
+#include "vfc.h"
+#include "vfc_i2c.h"
+
+#define WRITE_S1(__val) \
+        sbus_writel(__val, &dev->regs->i2c_s1)
+#define WRITE_REG(__val) \
+        sbus_writel(__val, &dev->regs->i2c_reg)
+
+#define VFC_I2C_READ (0x1)
+#define VFC_I2C_WRITE (0x0)
+     
+/****** 
+  The i2c bus controller chip on the VFC is a pcd8584t, but
+  phillips claims it doesn't exist.  As far as I can tell it is
+  identical to the PCF8584 so I treat it like it is the pcf8584.
+  
+  NOTE: The pcf8584 only cares
+  about the msb of the word you feed it 
+*****/
+
+int vfc_pcf8584_init(struct vfc_dev *dev) 
+{
+        /* This will also choose register S0_OWN so we can set it. */
+        WRITE_S1(RESET);
+
+        /* The pcf8584 shifts this value left one bit and uses
+         * it as its i2c bus address.
+         */
+        WRITE_REG(0x55000000);
+
+        /* This will set the i2c bus at the same speed sun uses,
+         * and set another magic bit.
+         */
+        WRITE_S1(SELECT(S2));
+        WRITE_REG(0x14000000);
+        
+        /* Enable the serial port, idle the i2c bus and set
+         * the data reg to s0.
+         */
+        WRITE_S1(CLEAR_I2C_BUS);
+        udelay(100);
+        return 0;
+}
+
+void vfc_i2c_delay_wakeup(struct vfc_dev *dev) 
+{
+        /* Used to profile code and eliminate too many delays */
+        VFC_I2C_DEBUG_PRINTK(("vfc%d: Delaying\n", dev->instance));
+        wake_up(&dev->poll_wait);
+}
+
+void vfc_i2c_delay_no_busy(struct vfc_dev *dev, unsigned long usecs) 
+{
+        init_timer(&dev->poll_timer);
+        dev->poll_timer.expires = jiffies + 
+                ((unsigned long)usecs*(HZ))/1000000;
+        dev->poll_timer.data=(unsigned long)dev;
+        dev->poll_timer.function=(void *)(unsigned long)vfc_i2c_delay_wakeup;
+        add_timer(&dev->poll_timer);
+        sleep_on(&dev->poll_wait);
+        del_timer(&dev->poll_timer);
+}
+
+void inline vfc_i2c_delay(struct vfc_dev *dev) 
+{ 
+        vfc_i2c_delay_no_busy(dev, 100);
+}
+
+int vfc_init_i2c_bus(struct vfc_dev *dev)
+{
+        WRITE_S1(ENABLE_SERIAL | SELECT(S0) | ACK);
+        vfc_i2c_reset_bus(dev);
+        return 0;
+}
+
+int vfc_i2c_reset_bus(struct vfc_dev *dev) 
+{
+        VFC_I2C_DEBUG_PRINTK((KERN_DEBUG "vfc%d: Resetting the i2c bus\n",
+                              dev->instance));
+        if(dev == NULL)
+                return -EINVAL;
+        if(dev->regs == NULL)
+                return -EINVAL;
+        WRITE_S1(SEND_I2C_STOP);
+        WRITE_S1(SEND_I2C_STOP | ACK);
+        vfc_i2c_delay(dev);
+        WRITE_S1(CLEAR_I2C_BUS);
+        VFC_I2C_DEBUG_PRINTK((KERN_DEBUG "vfc%d: I2C status %x\n",
+                              dev->instance,
+                              sbus_readl(&dev->regs->i2c_s1)));
+        return 0;
+}
+
+int vfc_i2c_wait_for_bus(struct vfc_dev *dev) 
+{
+        int timeout = 1000; 
+
+        while(!(sbus_readl(&dev->regs->i2c_s1) & BB)) {
+                if(!(timeout--))
+                        return -ETIMEDOUT;
+                vfc_i2c_delay(dev);
+        }
+        return 0;
+}
+
+int vfc_i2c_wait_for_pin(struct vfc_dev *dev, int ack)
+{
+        int timeout = 1000; 
+        int s1;
+
+        while ((s1 = sbus_readl(&dev->regs->i2c_s1)) & PIN) {
+                if (!(timeout--))
+                        return -ETIMEDOUT;
+                vfc_i2c_delay(dev);
+        }
+        if (ack == VFC_I2C_ACK_CHECK) {
+                if(s1 & LRB)
+                        return -EIO; 
+        }
+        return 0;
+}
+
+#define SHIFT(a) ((a) << 24)
+int vfc_i2c_xmit_addr(struct vfc_dev *dev, unsigned char addr, char mode) 
+{ 
+        int ret, raddr;
+#if 1
+        WRITE_S1(SEND_I2C_STOP | ACK);
+        WRITE_S1(SELECT(S0) | ENABLE_SERIAL);
+        vfc_i2c_delay(dev);
+#endif
+
+        switch(mode) {
+        case VFC_I2C_READ:
+                raddr = SHIFT(((unsigned int)addr | 0x1));
+                WRITE_REG(raddr);
+                VFC_I2C_DEBUG_PRINTK(("vfc%d: receiving from i2c addr 0x%x\n",
+                                      dev->instance, addr | 0x1));
+                break;
+        case VFC_I2C_WRITE:
+                raddr = SHIFT((unsigned int)addr & ~0x1);
+                WRITE_REG(raddr);
+                VFC_I2C_DEBUG_PRINTK(("vfc%d: sending to i2c addr 0x%x\n",
+                                      dev->instance, addr & ~0x1));
+                break;
+        default:
+                return -EINVAL;
+        };
+
+        WRITE_S1(SEND_I2C_START);
+        vfc_i2c_delay(dev);
+        ret = vfc_i2c_wait_for_pin(dev,VFC_I2C_ACK_CHECK); /* We wait
+                                                              for the
+                                                              i2c send
+                                                              to finish
+                                                              here but
+                                                              Sun
+                                                              doesn't,
+                                                              hmm */
+        if (ret) {
+                printk(KERN_ERR "vfc%d: VFC xmit addr timed out or no ack\n",
+                       dev->instance);
+                return ret;
+        } else if (mode == VFC_I2C_READ) {
+                if ((ret = sbus_readl(&dev->regs->i2c_reg) & 0xff000000) != raddr) {
+                        printk(KERN_WARNING 
+                               "vfc%d: returned slave address "
+                               "mismatch(%x,%x)\n",
+                               dev->instance, raddr, ret);
+                }
+        }       
+        return 0;
+}
+
+int vfc_i2c_xmit_byte(struct vfc_dev *dev,unsigned char *byte) 
+{
+        int ret;
+        u32 val = SHIFT((unsigned int)*byte);
+
+        WRITE_REG(val);
+
+        ret = vfc_i2c_wait_for_pin(dev, VFC_I2C_ACK_CHECK); 
+        switch(ret) {
+        case -ETIMEDOUT: 
+                printk(KERN_ERR "vfc%d: VFC xmit byte timed out or no ack\n",
+                       dev->instance);
+                break;
+        case -EIO:
+                ret = XMIT_LAST_BYTE;
+                break;
+        default:
+                break;
+        };
+
+        return ret;
+}
+
+int vfc_i2c_recv_byte(struct vfc_dev *dev, unsigned char *byte, int last) 
+{
+        int ret;
+
+        if (last) {
+                WRITE_REG(NEGATIVE_ACK);
+                VFC_I2C_DEBUG_PRINTK(("vfc%d: sending negative ack\n",
+                                      dev->instance));
+        } else {
+                WRITE_S1(ACK);
+        }
+
+        ret = vfc_i2c_wait_for_pin(dev, VFC_I2C_NO_ACK_CHECK);
+        if(ret) {
+                printk(KERN_ERR "vfc%d: "
+                       "VFC recv byte timed out\n",
+                       dev->instance);
+        }
+        *byte = (sbus_readl(&dev->regs->i2c_reg)) >> 24;
+        return ret;
+}
+
+int vfc_i2c_recvbuf(struct vfc_dev *dev, unsigned char addr,
+                    char *buf, int count)
+{
+        int ret, last;
+
+        if(!(count && buf && dev && dev->regs) )
+                return -EINVAL;
+
+        if ((ret = vfc_i2c_wait_for_bus(dev))) {
+                printk(KERN_ERR "vfc%d: VFC I2C bus busy\n", dev->instance);
+                return ret;
+        }
+
+        if ((ret = vfc_i2c_xmit_addr(dev, addr, VFC_I2C_READ))) {
+                WRITE_S1(SEND_I2C_STOP);
+                vfc_i2c_delay(dev);
+                return ret;
+        }
+        
+        last = 0;
+        while (count--) {
+                if (!count)
+                        last = 1;
+                if ((ret = vfc_i2c_recv_byte(dev, buf, last))) {
+                        printk(KERN_ERR "vfc%d: "
+                               "VFC error while receiving byte\n",
+                               dev->instance);
+                        WRITE_S1(SEND_I2C_STOP);
+                        ret = -EINVAL;
+                }
+                buf++;
+        }
+        WRITE_S1(SEND_I2C_STOP | ACK);
+        vfc_i2c_delay(dev);
+        return ret;
+}
+
+int vfc_i2c_sendbuf(struct vfc_dev *dev, unsigned char addr, 
+                    char *buf, int count) 
+{
+        int ret;
+        
+        if (!(buf && dev && dev->regs))
+                return -EINVAL;
+        
+        if ((ret = vfc_i2c_wait_for_bus(dev))) {
+                printk(KERN_ERR "vfc%d: VFC I2C bus busy\n", dev->instance);
+                return ret;
+        }
+        
+        if ((ret = vfc_i2c_xmit_addr(dev, addr, VFC_I2C_WRITE))) {
+                WRITE_S1(SEND_I2C_STOP);
+                vfc_i2c_delay(dev);
+                return ret;
+        }
+        
+        while(count--) {
+                ret = vfc_i2c_xmit_byte(dev, buf);
+                switch(ret) {
+                case XMIT_LAST_BYTE:
+                        VFC_I2C_DEBUG_PRINTK(("vfc%d: "
+                                              "Receiver ended transmission with "
+                                              " %d bytes remaining\n",
+                                              dev->instance, count));
+                        ret = 0;
+                        goto done;
+                        break;
+                case 0:
+                        break;
+                default:
+                        printk(KERN_ERR "vfc%d: "
+                               "VFC error while sending byte\n", dev->instance);
+                        break;
+                };
+
+                buf++;
+        }
+done:
+        WRITE_S1(SEND_I2C_STOP | ACK);
+        vfc_i2c_delay(dev);
+        return ret;
+}
+
+
+
+
+
+
+
+
+