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authordzu <dzu>2003-09-30 14:08:43 +0000
committerdzu <dzu>2003-09-30 14:08:43 +0000
commitab209d510710e0059260e3ea17c11741573296b9 (patch)
tree127c5d62873d5ca9caf847d33c6af50338e35d26 /cpu/mpc5xxx/i2c.c
parent87970ebeb5153bb8650d3f031148e82e30ec3584 (diff)
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Fix problems with I2C support for mpc5200
Diffstat (limited to 'cpu/mpc5xxx/i2c.c')
-rw-r--r--cpu/mpc5xxx/i2c.c58
1 files changed, 55 insertions, 3 deletions
diff --git a/cpu/mpc5xxx/i2c.c b/cpu/mpc5xxx/i2c.c
index 640d140..74a610f 100644
--- a/cpu/mpc5xxx/i2c.c
+++ b/cpu/mpc5xxx/i2c.c
@@ -28,15 +28,22 @@
#include <mpc5xxx.h>
#include <i2c.h>
-#ifdef CFG_I2C_MODULE
+#if (CFG_I2C_MODULE == 2)
#define I2C_BASE MPC5XXX_I2C2
-#else
+#elif (CFG_I2C_MODULE == 1)
#define I2C_BASE MPC5XXX_I2C1
+#else
+#error CFG_I2C_MODULE is not properly configured
#endif
#define I2C_TIMEOUT 100
#define I2C_RETRIES 3
+struct mpc5xxx_i2c_tap {
+ int scl2tap;
+ int tap2tap;
+};
+
static int mpc_reg_in (volatile u32 *reg);
static void mpc_reg_out (volatile u32 *reg, int val, int mask);
static int wait_for_bb (void);
@@ -44,6 +51,7 @@ static int wait_for_pin (int *status);
static int do_address (uchar chip, char rdwr_flag);
static int send_bytes (uchar chip, char *buf, int len);
static int receive_bytes (uchar chip, char *buf, int len);
+static int mpc_get_fdr (int);
static int mpc_reg_in(volatile u32 *reg)
{
@@ -207,7 +215,7 @@ void i2c_init(int speed, int saddr)
/* Set clock
*/
- mpc_reg_out(&regs->mfdr, speed, 0);
+ mpc_reg_out(&regs->mfdr, mpc_get_fdr(speed), 0);
/* Enable module
*/
@@ -217,6 +225,50 @@ void i2c_init(int speed, int saddr)
return;
}
+static int mpc_get_fdr(int speed)
+{
+ DECLARE_GLOBAL_DATA_PTR;
+ static int fdr = -1;
+ static int best_speed = 0;
+
+ if (fdr == -1) {
+ ulong ipb, scl;
+ ulong bestmatch = 0xffffffffUL;
+ int best_i = 0, best_j = 0, i, j;
+ int SCL_Tap[] = { 9, 10, 12, 15, 5, 6, 7, 8};
+ struct mpc5xxx_i2c_tap scltap[] = {
+ {4, 1},
+ {4, 2},
+ {6, 4},
+ {6, 8},
+ {14, 16},
+ {30, 32},
+ {62, 64},
+ {126, 128}
+ };
+
+ ipb = gd->ipb_clk;
+ for (i = 7; i >= 0; i--) {
+ for (j = 7; j >= 0; j--) {
+ scl = 2 * (scltap[j].scl2tap +
+ (SCL_Tap[i] - 1) * scltap[j].tap2tap + 2);
+ if (ipb <= speed*scl) {
+ if ((speed*scl - ipb) < bestmatch) {
+ bestmatch = speed*scl - ipb;
+ best_i = i;
+ best_j = j;
+ best_speed = ipb/scl;
+ }
+ }
+ }
+ }
+ fdr = (best_i & 3) | ((best_i & 4) << 3) | (best_j << 2);
+ printf("%d kHz, ", best_speed / 1000);
+ }
+
+ return fdr;
+}
+
int i2c_probe(uchar chip)
{
struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;