From 3c853f31d6a8e4407f73a2ca2c63d383a245f237 Mon Sep 17 00:00:00 2001 From: Jon Smirl Date: Sat, 4 Apr 2009 17:44:51 -0400 Subject: [PATCH] mpc5200: reduce delays in i2c The previous code waited 1000us before checking i2c status. Measurement shows i2c is usually ready in under 50us. Change the polling interval to 15us, loop 6,667 times to keep the polling timeout constant at 100ms. --- cpu/mpc5xxx/i2c.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/cpu/mpc5xxx/i2c.c b/cpu/mpc5xxx/i2c.c index e2506d82f2..23419324ba 100644 --- a/cpu/mpc5xxx/i2c.c +++ b/cpu/mpc5xxx/i2c.c @@ -38,7 +38,7 @@ DECLARE_GLOBAL_DATA_PTR; #error CONFIG_SYS_I2C_MODULE is not properly configured #endif -#define I2C_TIMEOUT 100 +#define I2C_TIMEOUT 6667 #define I2C_RETRIES 3 struct mpc5xxx_i2c_tap { @@ -94,7 +94,7 @@ static int wait_for_bb(void) mpc_reg_out(®s->mcr, 0, 0); mpc_reg_out(®s->mcr, I2C_EN, 0); #endif - udelay(1000); + udelay(15); status = mpc_reg_in(®s->msr); } @@ -109,7 +109,7 @@ static int wait_for_pin(int *status) *status = mpc_reg_in(®s->msr); while (timeout-- && !(*status & I2C_IF)) { - udelay(1000); + udelay(15); *status = mpc_reg_in(®s->msr); } -- 2.25.1