+struct omap_i2c {
+ struct udevice *clk;
+ struct i2c *regs;
+ unsigned int speed;
+ int waitdelay;
+ int clk_id;
+};
+
+static int omap24_i2c_findpsc(u32 *pscl, u32 *psch, uint speed)
+{
+ unsigned long internal_clk = 0, fclk;
+ unsigned int prescaler;
+
+ /*
+ * This method is only called for Standard and Fast Mode speeds
+ *
+ * For some TI SoCs it is explicitly written in TRM (e,g, SPRUHZ6G,
+ * page 5685, Table 24-7)
+ * that the internal I2C clock (after prescaler) should be between
+ * 7-12 MHz (at least for Fast Mode (FS)).
+ *
+ * Such approach is used in v4.9 Linux kernel in:
+ * ./drivers/i2c/busses/i2c-omap.c (omap_i2c_init function).
+ */
+
+ speed /= 1000; /* convert speed to kHz */
+
+ if (speed > 100)
+ internal_clk = 9600;
+ else
+ internal_clk = 4000;
+
+ fclk = I2C_IP_CLK / 1000;
+ prescaler = fclk / internal_clk;
+ prescaler = prescaler - 1;
+
+ if (speed > 100) {
+ unsigned long scl;
+
+ /* Fast mode */
+ scl = internal_clk / speed;
+ *pscl = scl - (scl / 3) - I2C_FASTSPEED_SCLL_TRIM;
+ *psch = (scl / 3) - I2C_FASTSPEED_SCLH_TRIM;
+ } else {
+ /* Standard mode */
+ *pscl = internal_clk / (speed * 2) - I2C_FASTSPEED_SCLL_TRIM;
+ *psch = internal_clk / (speed * 2) - I2C_FASTSPEED_SCLH_TRIM;
+ }
+
+ debug("%s: speed [kHz]: %d psc: 0x%x sscl: 0x%x ssch: 0x%x\n",
+ __func__, speed, prescaler, *pscl, *psch);
+
+ if (*pscl <= 0 || *psch <= 0 || prescaler <= 0)
+ return -EINVAL;
+
+ return prescaler;
+}