From 311595c60cb8a720e93205218042101b65830b29 Mon Sep 17 00:00:00 2001
From: Mark Arigo <markarigo@gmail.com>
Date: Fri, 13 Feb 2009 03:35:23 +0000
Subject: FS#9865 - For Portalplayer i2c, read up to 4 bytes at a time instead
 of one at a time (need for the upcoming Philips HDD1630 radio commit).

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@19995 a1c6a512-1295-4272-9138-f99709370657
---
 firmware/target/arm/i2c-pp.c | 68 ++++++++++++++++++++++++++++++--------------
 1 file changed, 46 insertions(+), 22 deletions(-)

diff --git a/firmware/target/arm/i2c-pp.c b/firmware/target/arm/i2c-pp.c
index 3db25c027c..175e2effd1 100644
--- a/firmware/target/arm/i2c-pp.c
+++ b/firmware/target/arm/i2c-pp.c
@@ -54,35 +54,46 @@ static int pp_i2c_wait_not_busy(void)
     return -1;
 }
 
-static int pp_i2c_read_byte(unsigned int addr, unsigned int *data)
+static int pp_i2c_read_bytes(unsigned int addr, int len, unsigned char *data)
 {
-    if (pp_i2c_wait_not_busy() < 0)
+    int i;
+
+    if (len < 1 || len > 4)
     {
         return -1;
     }
 
+    if (pp_i2c_wait_not_busy() < 0)
+    {
+        return -2;
+    }
+
     {
-        unsigned int byte;
         int old_irq_level = disable_irq_save();
 
         /* clear top 15 bits, left shift 1, or in 0x1 for a read */
-        I2C_ADDR = ((addr << 17) >> 16) | 0x1 ;
+        I2C_ADDR = ((addr << 17) >> 16) | 0x1;
 
         I2C_CTRL |= 0x20;
 
+        I2C_CTRL = (I2C_CTRL & ~0x6) | ((len-1) << 1);
+
         I2C_CTRL |= I2C_SEND;
 
         restore_irq(old_irq_level);
+
         if (pp_i2c_wait_not_busy() < 0)
         {
-            return -1;
+            return -2;
         }
-        old_irq_level = disable_irq_save();
 
-        byte = I2C_DATA(0);
+        old_irq_level = disable_irq_save();
 
         if (data)
-            *data = byte;
+        {
+            for ( i = 0; i < len; i++ )
+                *data++ = I2C_DATA(i);
+        }
 
         restore_irq(old_irq_level);
     }
@@ -90,9 +101,9 @@ static int pp_i2c_read_byte(unsigned int addr, unsigned int *data)
     return 0;
 }
 
-static int pp_i2c_send_bytes(unsigned int addr, unsigned int len, unsigned char *data)
+static int pp_i2c_send_bytes(unsigned int addr, int len, unsigned char *data)
 {
-    unsigned int i;
+    int i;
 
     if (len < 1 || len > 4)
     {
@@ -117,14 +128,14 @@ static int pp_i2c_send_bytes(unsigned int addr, unsigned int len, unsigned char
             I2C_DATA(i) = *data++;
         }
 
-        I2C_CTRL = (I2C_CTRL & ~0x26) | ((len-1) << 1);
+        I2C_CTRL = (I2C_CTRL & ~0x6) | ((len-1) << 1);
 
         I2C_CTRL |= I2C_SEND;
 
         restore_irq(old_irq_level);
     }
 
-    return 0x0;
+    return 0;
 }
 
 static int pp_i2c_send_byte(unsigned int addr, int data0)
@@ -147,29 +158,42 @@ void i2c_unlock(void)
     mutex_unlock(&i2c_mtx);
 }
 
-int i2c_readbytes(unsigned int dev_addr, int addr, int len, unsigned char *data) {
-    unsigned int temp;
-    int i;
+int i2c_readbytes(unsigned int dev_addr, int addr, int len, unsigned char *data)
+{
+    int i, n;
+
     mutex_lock(&i2c_mtx);
-    pp_i2c_send_byte(dev_addr, addr);
-    for (i = 0; i < len; i++) {
-        pp_i2c_read_byte(dev_addr, &temp);
-        data[i] = temp;
+
+    if (addr >= 0)
+        pp_i2c_send_byte(dev_addr, addr);
+
+    i = 0;
+    while (len > 0)
+    {
+        n = (len < 4) ? len : 4;
+
+        if (pp_i2c_read_bytes(dev_addr, n, data + i) < 0)
+            break;
+
+        len -= n;
+        i   += n;
     }
+
     mutex_unlock(&i2c_mtx);
+
     return i;
 }
 
 int i2c_readbyte(unsigned int dev_addr, int addr)
 {
-    int data;
+    unsigned char data;
 
     mutex_lock(&i2c_mtx);
     pp_i2c_send_byte(dev_addr, addr);
-    pp_i2c_read_byte(dev_addr, &data);
+    pp_i2c_read_bytes(dev_addr, 1, &data);
     mutex_unlock(&i2c_mtx);
 
-    return data;
+    return (int)data;
 }
 
 int pp_i2c_send(unsigned int addr, int data0, int data1)
-- 
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