Prepare v2017.07--rc2

[oweals/u-boot.git] / drivers / serial / serial_stm32x7.c

diff --git a/drivers/serial/serial_stm32x7.c b/drivers/serial/serial_stm32x7.c
index bdabf87e50eee856bb184f718e7c37b638acaa42..61e8167a3bc9e1d4df566aaccc61c27de6dacb4c 100644 (file)
--- a/drivers/serial/serial_stm32x7.c
+++ b/drivers/serial/serial_stm32x7.c
@@ -20,7 +20,7 @@ static int stm32_serial_setbrg(struct udevice *dev, int baudrate)
 {
        struct stm32x7_serial_platdata *plat = dev->platdata;
        struct stm32_usart *const usart = plat->base;
-       u32  clock, int_div, frac_div, tmp;
+       u32  clock, int_div, mantissa, fraction, oversampling;
 
        if (((u32)usart & STM32_BUS_MASK) == APB1_PERIPH_BASE)
                clock = clock_get(CLOCK_APB1);
@@ -29,11 +29,20 @@ static int stm32_serial_setbrg(struct udevice *dev, int baudrate)
        else
                return -EINVAL;
 
-       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);
 
        return 0;
 }
@@ -93,6 +102,9 @@ static int stm32_serial_probe(struct udevice *dev)
        }
 #endif
 
+       /* Disable usart-> disable overrun-> enable usart */
+       clrbits_le32(&usart->cr1, USART_CR1_RE | USART_CR1_TE | USART_CR1_UE);
+       setbits_le32(&usart->cr3, USART_CR3_OVRDIS);
        setbits_le32(&usart->cr1, USART_CR1_RE | USART_CR1_TE | USART_CR1_UE);
 
        return 0;
@@ -100,8 +112,8 @@ static int stm32_serial_probe(struct udevice *dev)
 
 #if CONFIG_IS_ENABLED(OF_CONTROL)
 static const struct udevice_id stm32_serial_id[] = {
-       {.compatible = "st,stm32-usart"},
-       {.compatible = "st,stm32-uart"},
+       {.compatible = "st,stm32f7-usart"},
+       {.compatible = "st,stm32f7-uart"},
        {}
 };