[U-Boot] [PATCH 4/5] i2c: omap24xx: Fix high speed trimming calculation

[Christophe Ricard]

Work based on i2c-omap.c from linux kernel.

fsscll/fssclh and hsscll/hssclh was always negative in high speed.

i2c high speed frequency start after 400Khz.

Signed-off-by: Christophe Ricard <christophe-h.ricard at st.com>
---

 drivers/i2c/omap24xx_i2c.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/i2c/omap24xx_i2c.c b/drivers/i2c/omap24xx_i2c.c
index 48ca446..774edaf 100644
--- a/drivers/i2c/omap24xx_i2c.c
+++ b/drivers/i2c/omap24xx_i2c.c
@@ -129,7 +129,9 @@ static int omap24_i2c_setspeed(struct udevice *adap, unsigned int speed)
 	i2c_base = i2c_bus->i2c_base;
 #endif
 
-	if (speed >= OMAP_I2C_HIGH_SPEED) {
+	if (speed > 400000) {
+		unsigned long scl;
+
 		/* High speed */
 		psc = I2C_IP_CLK / I2C_INTERNAL_SAMPLING_CLK;
 		psc -= 1;
@@ -139,12 +141,11 @@ static int omap24_i2c_setspeed(struct udevice *adap, unsigned int speed)
 		}
 
 		/* For first phase of HS mode */
-		fsscll = I2C_INTERNAL_SAMPLING_CLK / (2 * speed);
+		scl = I2C_INTERNAL_SAMPLING_CLK / 400000;
 
-		fssclh = fsscll;
+		fsscll = scl - (scl / 3) - 7;
+		fssclh = (scl / 3)  - 5;
 
-		fsscll -= I2C_HIGHSPEED_PHASE_ONE_SCLL_TRIM;
-		fssclh -= I2C_HIGHSPEED_PHASE_ONE_SCLH_TRIM;
 		if (((fsscll < 0) || (fssclh < 0)) ||
 		    ((fsscll > 255) || (fssclh > 255))) {
 			puts("Error : I2C initializing first phase clock\n");
@@ -152,10 +153,10 @@ static int omap24_i2c_setspeed(struct udevice *adap, unsigned int speed)
 		}
 
 		/* For second phase of HS mode */
-		hsscll = hssclh = I2C_INTERNAL_SAMPLING_CLK / (2 * speed);
+		scl = I2C_IP_CLK / speed;
+		hsscll = scl - (scl / 3) - 7;
+		hssclh = (scl / 3) - 5;
 
-		hsscll -= I2C_HIGHSPEED_PHASE_TWO_SCLL_TRIM;
-		hssclh -= I2C_HIGHSPEED_PHASE_TWO_SCLH_TRIM;
 		if (((fsscll < 0) || (fssclh < 0)) ||
 		    ((fsscll > 255) || (fssclh > 255))) {
 			puts("Error : I2C initializing second phase clock\n");
-- 
2.5.0