stm32x7: add support for stm32x7 serial driver
This patch adds support for stm32f7 family usart peripheral.
Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/serial/serial_stm32x7.c b/drivers/serial/serial_stm32x7.c
new file mode 100644
index 0000000..cfbfab7
--- /dev/null
+++ b/drivers/serial/serial_stm32x7.c
@@ -0,0 +1,83 @@
+/*
+ * (C) Copyright 2016
+ * Vikas Manocha, <vikas.manocha@st.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <asm/io.h>
+#include <serial.h>
+#include <dm/platform_data/serial_stm32x7.h>
+#include "serial_stm32x7.h"
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static int stm32_serial_setbrg(struct udevice *dev, int baudrate)
+{
+ struct stm32x7_serial_platdata *plat = dev->platdata;
+ struct stm32_usart *const usart = plat->base;
+ writel(plat->clock/baudrate, &usart->brr);
+
+ return 0;
+}
+
+static int stm32_serial_getc(struct udevice *dev)
+{
+ struct stm32x7_serial_platdata *plat = dev->platdata;
+ struct stm32_usart *const usart = plat->base;
+
+ if ((readl(&usart->sr) & USART_SR_FLAG_RXNE) == 0)
+ return -EAGAIN;
+
+ return readl(&usart->rd_dr);
+}
+
+static int stm32_serial_putc(struct udevice *dev, const char c)
+{
+ struct stm32x7_serial_platdata *plat = dev->platdata;
+ struct stm32_usart *const usart = plat->base;
+
+ if ((readl(&usart->sr) & USART_SR_FLAG_TXE) == 0)
+ return -EAGAIN;
+
+ writel(c, &usart->tx_dr);
+
+ return 0;
+}
+
+static int stm32_serial_pending(struct udevice *dev, bool input)
+{
+ struct stm32x7_serial_platdata *plat = dev->platdata;
+ struct stm32_usart *const usart = plat->base;
+
+ if (input)
+ return readl(&usart->sr) & USART_SR_FLAG_RXNE ? 1 : 0;
+ else
+ return readl(&usart->sr) & USART_SR_FLAG_TXE ? 0 : 1;
+}
+
+static int stm32_serial_probe(struct udevice *dev)
+{
+ struct stm32x7_serial_platdata *plat = dev->platdata;
+ struct stm32_usart *const usart = plat->base;
+ setbits_le32(&usart->cr1, USART_CR1_RE | USART_CR1_TE | USART_CR1_UE);
+
+ return 0;
+}
+
+static const struct dm_serial_ops stm32_serial_ops = {
+ .putc = stm32_serial_putc,
+ .pending = stm32_serial_pending,
+ .getc = stm32_serial_getc,
+ .setbrg = stm32_serial_setbrg,
+};
+
+U_BOOT_DRIVER(serial_stm32) = {
+ .name = "serial_stm32x7",
+ .id = UCLASS_SERIAL,
+ .ops = &stm32_serial_ops,
+ .probe = stm32_serial_probe,
+ .flags = DM_FLAG_PRE_RELOC,
+};