- int_div = (25 * clock) / (4 * baudrate);
- tmp = ((int_div / 100) << USART_BRR_M_SHIFT) & USART_BRR_M_MASK;
- frac_div = int_div - (100 * (tmp >> USART_BRR_M_SHIFT));
- tmp |= (((frac_div * 16) + 50) / 100) & USART_BRR_F_MASK;
- writel(tmp, &usart->brr);
+ int_div = DIV_ROUND_CLOSEST(clock, baudrate);
+
+ if (int_div < 16) {
+ oversampling = 8;
+ setbits_le32(&usart->cr1, USART_CR1_OVER8);
+ } else {
+ oversampling = 16;
+ clrbits_le32(&usart->cr1, USART_CR1_OVER8);
+ }
+
+ mantissa = (int_div / oversampling) << USART_BRR_M_SHIFT;
+ fraction = int_div % oversampling;
+
+ writel(mantissa | fraction, &usart->brr);