Merge branch 'master' of git://git.denx.de/u-boot-samsung

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

diff --git a/drivers/serial/serial_stm32x7.c b/drivers/serial/serial_stm32x7.c
index 592c0bd..61e8167 100644 (file)
--- a/drivers/serial/serial_stm32x7.c
+++ b/drivers/serial/serial_stm32x7.c
@@ -6,6 +6,7 @@
  */
 
 #include <common.h>
+#include <clk.h>
 #include <dm.h>
 #include <asm/io.h>
 #include <serial.h>
@@ -19,7 +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);
@@ -28,11 +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;
 }
@@ -76,11 +86,52 @@ static int stm32_serial_probe(struct udevice *dev)
 {
        struct stm32x7_serial_platdata *plat = dev->platdata;
        struct stm32_usart *const usart = plat->base;
+
+#ifdef CONFIG_CLK
+       int ret;
+       struct clk clk;
+
+       ret = clk_get_by_index(dev, 0, &clk);
+       if (ret < 0)
+               return ret;
+
+       ret = clk_enable(&clk);
+       if (ret) {
+               dev_err(dev, "failed to enable clock\n");
+               return ret;
+       }
+#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;
 }
 
+#if CONFIG_IS_ENABLED(OF_CONTROL)
+static const struct udevice_id stm32_serial_id[] = {
+       {.compatible = "st,stm32f7-usart"},
+       {.compatible = "st,stm32f7-uart"},
+       {}
+};
+
+static int stm32_serial_ofdata_to_platdata(struct udevice *dev)
+{
+       struct stm32x7_serial_platdata *plat = dev_get_platdata(dev);
+       fdt_addr_t addr;
+
+       addr = devfdt_get_addr(dev);
+       if (addr == FDT_ADDR_T_NONE)
+               return -EINVAL;
+
+       plat->base = (struct stm32_usart *)addr;
+
+       return 0;
+}
+#endif
+
 static const struct dm_serial_ops stm32_serial_ops = {
        .putc = stm32_serial_putc,
        .pending = stm32_serial_pending,
@@ -91,6 +142,9 @@ static const struct dm_serial_ops stm32_serial_ops = {
 U_BOOT_DRIVER(serial_stm32) = {
        .name = "serial_stm32x7",
        .id = UCLASS_SERIAL,
+       .of_match = of_match_ptr(stm32_serial_id),
+       .ofdata_to_platdata = of_match_ptr(stm32_serial_ofdata_to_platdata),
+       .platdata_auto_alloc_size = sizeof(struct stm32x7_serial_platdata),
        .ops = &stm32_serial_ops,
        .probe = stm32_serial_probe,
        .flags = DM_FLAG_PRE_RELOC,