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-rw-r--r--drivers/i2c/omap24xx_i2c.c74
1 files changed, 67 insertions, 7 deletions
diff --git a/drivers/i2c/omap24xx_i2c.c b/drivers/i2c/omap24xx_i2c.c
index 6784603..1a4c8c9 100644
--- a/drivers/i2c/omap24xx_i2c.c
+++ b/drivers/i2c/omap24xx_i2c.c
@@ -31,7 +31,69 @@ static void flush_fifo(void);
void i2c_init (int speed, int slaveadd)
{
- u16 scl;
+ int psc, fsscll, fssclh;
+ int hsscll = 0, hssclh = 0;
+ u32 scll, sclh;
+
+ /* Only handle standard, fast and high speeds */
+ if ((speed != OMAP_I2C_STANDARD) &&
+ (speed != OMAP_I2C_FAST_MODE) &&
+ (speed != OMAP_I2C_HIGH_SPEED)) {
+ printf("Error : I2C unsupported speed %d\n", speed);
+ return;
+ }
+
+ psc = I2C_IP_CLK / I2C_INTERNAL_SAMPLING_CLK;
+ psc -= 1;
+ if (psc < I2C_PSC_MIN) {
+ printf("Error : I2C unsupported prescalar %d\n", psc);
+ return;
+ }
+
+ if (speed == OMAP_I2C_HIGH_SPEED) {
+ /* High speed */
+
+ /* For first phase of HS mode */
+ fsscll = fssclh = I2C_INTERNAL_SAMPLING_CLK /
+ (2 * OMAP_I2C_FAST_MODE);
+
+ fsscll -= I2C_HIGHSPEED_PHASE_ONE_SCLL_TRIM;
+ fssclh -= I2C_HIGHSPEED_PHASE_ONE_SCLH_TRIM;
+ if (((fsscll < 0) || (fssclh < 0)) ||
+ ((fsscll > 255) || (fssclh > 255))) {
+ printf("Error : I2C initializing first phase clock\n");
+ return;
+ }
+
+ /* For second phase of HS mode */
+ hsscll = hssclh = I2C_INTERNAL_SAMPLING_CLK / (2 * speed);
+
+ hsscll -= I2C_HIGHSPEED_PHASE_TWO_SCLL_TRIM;
+ hssclh -= I2C_HIGHSPEED_PHASE_TWO_SCLH_TRIM;
+ if (((fsscll < 0) || (fssclh < 0)) ||
+ ((fsscll > 255) || (fssclh > 255))) {
+ printf("Error : I2C initializing second phase clock\n");
+ return;
+ }
+
+ scll = (unsigned int)hsscll << 8 | (unsigned int)fsscll;
+ sclh = (unsigned int)hssclh << 8 | (unsigned int)fssclh;
+
+ } else {
+ /* Standard and fast speed */
+ fsscll = fssclh = I2C_INTERNAL_SAMPLING_CLK / (2 * speed);
+
+ fsscll -= I2C_FASTSPEED_SCLL_TRIM;
+ fssclh -= I2C_FASTSPEED_SCLH_TRIM;
+ if (((fsscll < 0) || (fssclh < 0)) ||
+ ((fsscll > 255) || (fssclh > 255))) {
+ printf("Error : I2C initializing clock\n");
+ return;
+ }
+
+ scll = (unsigned int)fsscll;
+ sclh = (unsigned int)fssclh;
+ }
writew(0x2, I2C_SYSC); /* for ES2 after soft reset */
udelay(1000);
@@ -42,12 +104,10 @@ void i2c_init (int speed, int slaveadd)
udelay (50000);
}
- /* 12MHz I2C module clock */
- writew (0, I2C_PSC);
- speed = speed/1000; /* 100 or 400 */
- scl = ((12000/(speed*2)) - 7); /* use 7 when PSC = 0 */
- writew (scl, I2C_SCLL);
- writew (scl, I2C_SCLH);
+ writew(psc, I2C_PSC);
+ writew(scll, I2C_SCLL);
+ writew(sclh, I2C_SCLH);
+
/* own address */
writew (slaveadd, I2C_OA);
writew (I2C_CON_EN, I2C_CON);