Changeset 3877

Timestamp:

12/20/03 00:49:29 (9 years ago)

Author:

mds

Message:

add emulated block read and block process call support;

patch as received from: Liu Tao <lt@…>
My tweaks to follow

---

Here is the patch to support SMBus Block Read and SMBus Block Process Call
protocols under I2C emulation. It adds the I2C_M_RECV_LEN flag.

To support the two protocols, an algorithm driver should handle the
I2C_M_RECV_LEN flag in its master_xfer routin, and return
I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_READ_BLOCK_DATA or
I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_PROC_CALL
in its functionality routin.

Existing algorithm drivers won't be affected by this patch.

-- Regards, Liu Tao

Location:

i2c/trunk/kernel

Files:

• i2c-algo-bit.c (modified) (3 diffs)
• i2c-core.c (modified) (3 diffs)
• i2c.h (modified) (1 diff)

i2c/trunk/kernel/i2c-algo-bit.c

@@ -379 +379 @@
         char *temp = msg->buf;
         int count = msg->len;
+        int recv_len = 0;
+
+        /* Receive [Count] for I2C_SMBUS_BLOCK_DATA or I2C_SMBUS_BLOCK_PROC_CALL protocol */
+        if (msg->flags & I2C_M_RECV_LEN)
+                recv_len = 1;
 
         while (count > 0) {
@@ -391 +396 @@
                 }
 
+                if (recv_len) {
+                        recv_len = 0;
+                        /* [Count] should be between 1 and 31 (I2C_SMBUS_BLOCK_MAX - 1). */
+                        if (inval > 0 && inval < I2C_SMBUS_BLOCK_MAX) {
+                                count = inval + 1;      /* plus one for [Count] itself */
+                                msg->len = count;
+                        } else {
+                                printk(KERN_ERR "i2c-algo-bit.o: readbytes: bad block count (%d).\n", inval);
+                                break;
+                        }
+                }
+                
                 if ( count > 1 ) {              /* send ack */
                         sdalo(adap);
@@ -518 +535 @@
 {
         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR | 
-               I2C_FUNC_PROTOCOL_MANGLING;
+               I2C_FUNC_PROTOCOL_MANGLING |
+               I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
+               I2C_FUNC_SMBUS_READ_BLOCK_DATA;
 }
 

i2c/trunk/kernel/i2c-core.c

@@ -1260 +1260 @@
         case I2C_SMBUS_BLOCK_DATA_PEC:
                 if (read_write == I2C_SMBUS_READ) {
-                        printk(KERN_ERR "i2c-core.o: Block read not supported "
-                               "under I2C emulation!\n");
-                        return -1;
+                        /* I2C_FUNC_SMBUS_EMUL doesn't include I2C_FUNC_SMBUS_READ_BLOCK_DATA */
+                        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BLOCK_DATA)) {
+                                printk(KERN_ERR "i2c-core.o: Block read not supported "
+                                       "under I2C emulation!\n");
+                                return -1;
+                        }
+                        /* set send message */
+                        msg[0].len = 1;
+                        /* set recv message */
+                        msg[1].flags |= I2C_M_RECV_LEN;
+                        msg[1].len = I2C_SMBUS_BLOCK_MAX + 1;
+                        if (size == I2C_SMBUS_BLOCK_DATA_PEC)
+                                msg[1].len++;
                 } else {
                         msg[0].len = data->block[0] + 2;
@@ -1279 +1289 @@
         case I2C_SMBUS_BLOCK_PROC_CALL:
         case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
-                printk(KERN_ERR "i2c-core.o: Block process call not supported "
-                       "under I2C emulation!\n");
-                return -1;
+                /* I2C_FUNC_SMBUS_EMUL doesn't include I2C_FUNC_SMBUS_BLOCK_PROC_CALL */
+                if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BLOCK_PROC_CALL)) {
+                        printk(KERN_ERR "i2c-core.o: adapter doesn't support block process call!\n");
+                        return -1;
+                }
+
+                /* Another special case */
+                num = 2;
+                read_write = I2C_SMBUS_READ;
+                
+                /* set send message */
+                msg[0].len = data->block[0] + 2;
+                if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
+                        printk(KERN_ERR "i2c-core.o: smbus_access called with "
+                                "invalid block write size (%d)\n", data->block[0]);
+                        return -1;
+                }
+                for (i = 1; i <= msg[0].len; i++)
+                        msgbuf0[i] = data->block[i-1];
+                
+                /* set recv message */
+                msg[1].flags |= I2C_M_RECV_LEN;
+                msg[1].len = I2C_SMBUS_BLOCK_MAX + 1;
+                if (size == I2C_SMBUS_BLOCK_PROC_CALL_PEC)
+                        msg[1].len++;
+                break;
         case I2C_SMBUS_I2C_BLOCK_DATA:
                 if (read_write == I2C_SMBUS_READ) {
@@ -1324 +1357 @@
                                         data->block[i+1] = msgbuf1[i];
                                 break;
+                        case I2C_SMBUS_BLOCK_DATA:
+                        case I2C_SMBUS_BLOCK_DATA_PEC:
+                        case I2C_SMBUS_BLOCK_PROC_CALL:
+                        case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
+                                for (i = 0; i < I2C_SMBUS_BLOCK_MAX + 2; i++)
+                                        data->block[i] = msgbuf1[i];
+                                break;
                 }
         return 0;

i2c/trunk/kernel/i2c.h

@@ -362 +362 @@
 #define I2C_M_IGNORE_NAK        0x1000
 #define I2C_M_NO_RD_ACK         0x0800
+#define I2C_M_RECV_LEN          0x0400
         __u16 len;              /* msg length                           */
         __u8 *buf;              /* pointer to msg data                  */