stm32f4: Add serial driver
Signed-off-by: Kamil Lulko <rev13@wp.pl>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index b385852..d183eed 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -44,6 +44,7 @@
obj-$(CONFIG_UNIPHIER_SERIAL) += serial_uniphier.o
obj-$(CONFIG_OMAP_SERIAL) += serial_omap.o
obj-$(CONFIG_X86_SERIAL) += serial_x86.o
+obj-$(CONFIG_STM32_SERIAL) += serial_stm32.o
ifndef CONFIG_SPL_BUILD
obj-$(CONFIG_USB_TTY) += usbtty.o
diff --git a/drivers/serial/serial.c b/drivers/serial/serial.c
index 9f78492..699c410 100644
--- a/drivers/serial/serial.c
+++ b/drivers/serial/serial.c
@@ -154,6 +154,7 @@
serial_initfunc(sandbox_serial_initialize);
serial_initfunc(sconsole_serial_initialize);
serial_initfunc(sh_serial_initialize);
+serial_initfunc(stm32_serial_initialize);
serial_initfunc(uartlite_serial_initialize);
serial_initfunc(zynq_serial_initialize);
@@ -246,6 +247,7 @@
sandbox_serial_initialize();
sconsole_serial_initialize();
sh_serial_initialize();
+ stm32_serial_initialize();
uartlite_serial_initialize();
zynq_serial_initialize();
diff --git a/drivers/serial/serial_stm32.c b/drivers/serial/serial_stm32.c
new file mode 100644
index 0000000..3c80096
--- /dev/null
+++ b/drivers/serial/serial_stm32.c
@@ -0,0 +1,117 @@
+/*
+ * (C) Copyright 2015
+ * Kamil Lulko, <rev13@wp.pl>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <serial.h>
+#include <asm/arch/stm32.h>
+
+#define STM32_USART1_BASE (STM32_APB2PERIPH_BASE + 0x1000)
+#define RCC_APB2ENR_USART1EN (1 << 4)
+
+#define USART_BASE STM32_USART1_BASE
+#define RCC_USART_ENABLE RCC_APB2ENR_USART1EN
+
+struct stm32_serial {
+ u32 sr;
+ u32 dr;
+ u32 brr;
+ u32 cr1;
+ u32 cr2;
+ u32 cr3;
+ u32 gtpr;
+};
+
+#define USART_CR1_RE (1 << 2)
+#define USART_CR1_TE (1 << 3)
+#define USART_CR1_UE (1 << 13)
+
+#define USART_SR_FLAG_RXNE (1 << 5)
+#define USART_SR_FLAG_TXE (1 << 7)
+
+#define USART_BRR_F_MASK 0xF
+#define USART_BRR_M_SHIFT 4
+#define USART_BRR_M_MASK 0xFFF0
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static void stm32_serial_setbrg(void)
+{
+ serial_init();
+}
+
+static int stm32_serial_init(void)
+{
+ struct stm32_serial *usart = (struct stm32_serial *)USART_BASE;
+ u32 clock, int_div, frac_div, tmp;
+
+ if ((USART_BASE & STM32_BUS_MASK) == STM32_APB1PERIPH_BASE) {
+ setbits_le32(&STM32_RCC->apb1enr, RCC_USART_ENABLE);
+ clock = clock_get(CLOCK_APB1);
+ } else if ((USART_BASE & STM32_BUS_MASK) == STM32_APB2PERIPH_BASE) {
+ setbits_le32(&STM32_RCC->apb2enr, RCC_USART_ENABLE);
+ clock = clock_get(CLOCK_APB2);
+ } else {
+ return -1;
+ }
+
+ int_div = (25 * clock) / (4 * gd->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);
+ setbits_le32(&usart->cr1, USART_CR1_RE | USART_CR1_TE | USART_CR1_UE);
+
+ return 0;
+}
+
+static int stm32_serial_getc(void)
+{
+ struct stm32_serial *usart = (struct stm32_serial *)USART_BASE;
+ while ((readl(&usart->sr) & USART_SR_FLAG_RXNE) == 0)
+ ;
+ return readl(&usart->dr);
+}
+
+static void stm32_serial_putc(const char c)
+{
+ struct stm32_serial *usart = (struct stm32_serial *)USART_BASE;
+ while ((readl(&usart->sr) & USART_SR_FLAG_TXE) == 0)
+ ;
+ writel(c, &usart->dr);
+}
+
+static int stm32_serial_tstc(void)
+{
+ struct stm32_serial *usart = (struct stm32_serial *)USART_BASE;
+ u8 ret;
+
+ ret = readl(&usart->sr) & USART_SR_FLAG_RXNE;
+ return ret;
+}
+
+static struct serial_device stm32_serial_drv = {
+ .name = "stm32_serial",
+ .start = stm32_serial_init,
+ .stop = NULL,
+ .setbrg = stm32_serial_setbrg,
+ .putc = stm32_serial_putc,
+ .puts = default_serial_puts,
+ .getc = stm32_serial_getc,
+ .tstc = stm32_serial_tstc,
+};
+
+void stm32_serial_initialize(void)
+{
+ serial_register(&stm32_serial_drv);
+}
+
+__weak struct serial_device *default_serial_console(void)
+{
+ return &stm32_serial_drv;
+}