Merge tag 'u-boot-amlogic-20200727' of https://gitlab.denx.de/u-boot/custodians/u...

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

diff --git a/drivers/serial/serial_meson.c b/drivers/serial/serial_meson.c
index 8cf849f..496a2ca 100644 (file)
--- a/drivers/serial/serial_meson.c
+++ b/drivers/serial/serial_meson.c
@@ -65,14 +65,36 @@ static int meson_serial_probe(struct udevice *dev)
        return 0;
 }
 
+static void meson_serial_rx_error(struct udevice *dev)
+{
+       struct meson_serial_platdata *plat = dev->platdata;
+       struct meson_uart *const uart = plat->reg;
+       u32 val = readl(&uart->control);
+
+       /* Clear error */
+       val |= AML_UART_CLR_ERR;
+       writel(val, &uart->control);
+       val &= ~AML_UART_CLR_ERR;
+       writel(val, &uart->control);
+
+       /* Remove spurious byte from fifo */
+       readl(&uart->rfifo);
+}
+
 static int meson_serial_getc(struct udevice *dev)
 {
        struct meson_serial_platdata *plat = dev->platdata;
        struct meson_uart *const uart = plat->reg;
+       uint32_t status = readl(&uart->status);
 
-       if (readl(&uart->status) & AML_UART_RX_EMPTY)
+       if (status & AML_UART_RX_EMPTY)
                return -EAGAIN;
 
+       if (status & AML_UART_ERR) {
+               meson_serial_rx_error(dev);
+               return -EIO;
+       }
+
        return readl(&uart->rfifo) & 0xff;
 }
 
@@ -95,10 +117,23 @@ static int meson_serial_pending(struct udevice *dev, bool input)
        struct meson_uart *const uart = plat->reg;
        uint32_t status = readl(&uart->status);
 
-       if (input)
-               return !(status & AML_UART_RX_EMPTY);
-       else
+       if (input) {
+               if (status & AML_UART_RX_EMPTY)
+                       return false;
+
+               /*
+                * Handle and drop any RX error here to avoid
+                * returning true here when an error byte is in the FIFO
+                */
+               if (status & AML_UART_ERR) {
+                       meson_serial_rx_error(dev);
+                       return false;
+               }
+
+               return true;
+       } else {
                return !(status & AML_UART_TX_FULL);
+       }
 }
 
 static int meson_serial_ofdata_to_platdata(struct udevice *dev)