[PATCH 1/1] lib: utils/serial: Add support for Gaisler APBUART
Daniel Cederman
cederman at gaisler.com
Fri Apr 30 07:35:56 BST 2021
This patch adds support for the UART used by the NOEL-V processor.
Cobham Gaisler's NOEL-V RISC-V processor IP is available under GPL
and commercial license and is described in more detail at
https://www.gaisler.com/noelv.
Signed-off-by: Daniel Cederman <cederman at gaisler.com>
---
include/sbi_utils/fdt/fdt_helper.h | 3 +
include/sbi_utils/serial/gaisler-uart.h | 17 +++++
lib/utils/fdt/fdt_helper.c | 40 ++++++++++++
lib/utils/serial/fdt_serial.c | 2 +
lib/utils/serial/fdt_serial_gaisler.c | 35 ++++++++++
lib/utils/serial/gaisler-uart.c | 86 +++++++++++++++++++++++++
lib/utils/serial/objects.mk | 2 +
7 files changed, 185 insertions(+)
create mode 100644 include/sbi_utils/serial/gaisler-uart.h
create mode 100644 lib/utils/serial/fdt_serial_gaisler.c
create mode 100644 lib/utils/serial/gaisler-uart.c
diff --git a/include/sbi_utils/fdt/fdt_helper.h b/include/sbi_utils/fdt/fdt_helper.h
index f5222de..c89f2e6 100644
--- a/include/sbi_utils/fdt/fdt_helper.h
+++ b/include/sbi_utils/fdt/fdt_helper.h
@@ -39,6 +39,9 @@ int fdt_parse_hart_id(void *fdt, int cpu_offset, u32 *hartid);
int fdt_parse_max_hart_id(void *fdt, u32 *max_hartid);
+int fdt_parse_gaisler_uart_node(void *fdt, int nodeoffset,
+ struct platform_uart_data *uart);
+
int fdt_parse_shakti_uart_node(void *fdt, int nodeoffset,
struct platform_uart_data *uart);
diff --git a/include/sbi_utils/serial/gaisler-uart.h b/include/sbi_utils/serial/gaisler-uart.h
new file mode 100644
index 0000000..11d1f20
--- /dev/null
+++ b/include/sbi_utils/serial/gaisler-uart.h
@@ -0,0 +1,17 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2021 Cobham Gaisler AB.
+ *
+ * Authors:
+ * Daniel Cederman <cederman at gaisler.com>
+ */
+
+#ifndef __SERIAL_GAISLER_APBUART_H__
+#define __SERIAL_GAISLER_APBUART_H__
+
+#include <sbi/sbi_types.h>
+
+int gaisler_uart_init(unsigned long base, u32 in_freq, u32 baudrate);
+
+#endif
diff --git a/lib/utils/fdt/fdt_helper.c b/lib/utils/fdt/fdt_helper.c
index 909de01..9143e44 100644
--- a/lib/utils/fdt/fdt_helper.c
+++ b/lib/utils/fdt/fdt_helper.c
@@ -26,6 +26,8 @@
#define DEFAULT_SIFIVE_UART_REG_SHIFT 0
#define DEFAULT_SIFIVE_UART_REG_IO_WIDTH 4
+#define DEFAULT_GAISLER_UART_REG_IO_WIDTH 4
+
#define DEFAULT_SHAKTI_UART_FREQ 50000000
#define DEFAULT_SHAKTI_UART_BAUD 115200
@@ -213,6 +215,44 @@ int fdt_parse_max_hart_id(void *fdt, u32 *max_hartid)
return 0;
}
+int fdt_parse_gaisler_uart_node(void *fdt, int nodeoffset,
+ struct platform_uart_data *uart)
+{
+ int len, rc;
+ const fdt32_t *val;
+ unsigned long reg_addr, reg_size;
+
+ if (nodeoffset < 0 || !uart || !fdt)
+ return SBI_ENODEV;
+
+ rc = fdt_get_node_addr_size(fdt, nodeoffset, ®_addr, ®_size);
+ if (rc < 0 || !reg_addr || !reg_size)
+ return SBI_ENODEV;
+ uart->addr = reg_addr;
+
+ /**
+ * UART address is mandatory. clock-frequency and current-speed
+ * may not be present. Don't return error.
+ */
+ val = (fdt32_t *)fdt_getprop(fdt, nodeoffset, "clock-frequency", &len);
+ if (len > 0 && val)
+ uart->freq = fdt32_to_cpu(*val);
+ else
+ uart->freq = DEFAULT_UART_FREQ;
+
+ val = (fdt32_t *)fdt_getprop(fdt, nodeoffset, "current-speed", &len);
+ if (len > 0 && val)
+ uart->baud = fdt32_to_cpu(*val);
+ else
+ uart->baud = DEFAULT_UART_BAUD;
+
+ /* For Gaisler APBUART, the reg-shift and reg-io-width are fixed .*/
+ uart->reg_shift = DEFAULT_UART_REG_SHIFT;
+ uart->reg_io_width = DEFAULT_GAISLER_UART_REG_IO_WIDTH;
+
+ return 0;
+}
+
int fdt_parse_shakti_uart_node(void *fdt, int nodeoffset,
struct platform_uart_data *uart)
{
diff --git a/lib/utils/serial/fdt_serial.c b/lib/utils/serial/fdt_serial.c
index 43c55e8..bad3387 100644
--- a/lib/utils/serial/fdt_serial.c
+++ b/lib/utils/serial/fdt_serial.c
@@ -16,12 +16,14 @@ extern struct fdt_serial fdt_serial_uart8250;
extern struct fdt_serial fdt_serial_sifive;
extern struct fdt_serial fdt_serial_htif;
extern struct fdt_serial fdt_serial_shakti;
+extern struct fdt_serial fdt_serial_gaisler;
static struct fdt_serial *serial_drivers[] = {
&fdt_serial_uart8250,
&fdt_serial_sifive,
&fdt_serial_htif,
&fdt_serial_shakti,
+ &fdt_serial_gaisler
};
static struct fdt_serial dummy = {
diff --git a/lib/utils/serial/fdt_serial_gaisler.c b/lib/utils/serial/fdt_serial_gaisler.c
new file mode 100644
index 0000000..9a9f9a8
--- /dev/null
+++ b/lib/utils/serial/fdt_serial_gaisler.c
@@ -0,0 +1,35 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2021 Cobham Gaisler AB.
+ *
+ * Authors:
+ * Daniel Cederman <cederman at gaisler.com>
+ */
+
+#include <sbi_utils/fdt/fdt_helper.h>
+#include <sbi_utils/serial/fdt_serial.h>
+#include <sbi_utils/serial/gaisler-uart.h>
+
+static int serial_gaisler_init(void *fdt, int nodeoff,
+ const struct fdt_match *match)
+{
+ int rc;
+ struct platform_uart_data uart;
+
+ rc = fdt_parse_gaisler_uart_node(fdt, nodeoff, &uart);
+ if (rc)
+ return rc;
+
+ return gaisler_uart_init(uart.addr, uart.freq, uart.baud);
+}
+
+static const struct fdt_match serial_gaisler_match[] = {
+ { .compatible = "gaisler,apbuart" },
+ {},
+};
+
+struct fdt_serial fdt_serial_gaisler = {
+ .match_table = serial_gaisler_match,
+ .init = serial_gaisler_init
+};
diff --git a/lib/utils/serial/gaisler-uart.c b/lib/utils/serial/gaisler-uart.c
new file mode 100644
index 0000000..49298e9
--- /dev/null
+++ b/lib/utils/serial/gaisler-uart.c
@@ -0,0 +1,86 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2021 Cobham Gaisler AB.
+ *
+ * Authors:
+ * Daniel Cederman <cederman at gaisler.com>
+ */
+
+#include <sbi/riscv_io.h>
+#include <sbi/sbi_console.h>
+#include <sbi_utils/serial/gaisler-uart.h>
+
+/* clang-format off */
+
+#define UART_REG_DATA 0
+#define UART_REG_STATUS 1
+#define UART_REG_CTRL 2
+#define UART_REG_SCALER 3
+
+#define UART_DATA_DATA 0x000000ff
+#define UART_STATUS_FIFOFULL 0x00000200
+#define UART_STATUS_DATAREADY 0x00000001
+
+#define UART_CTRL_DB (1<<11)
+#define UART_CTRL_FL (1<<6)
+#define UART_CTRL_TE (1<<1)
+#define UART_CTRL_RE (1<<0)
+
+/* clang-format on */
+
+static volatile void *uart_base;
+
+static u32 get_reg(u32 num)
+{
+ return readl(uart_base + (num * 0x4));
+}
+
+static void set_reg(u32 num, u32 val)
+{
+ writel(val, uart_base + (num * 0x4));
+}
+
+static void gaisler_uart_putc(char ch)
+{
+ while (get_reg(UART_REG_STATUS) & UART_STATUS_FIFOFULL)
+ ;
+
+ set_reg(UART_REG_DATA, ch);
+}
+
+static int gaisler_uart_getc(void)
+{
+ u32 ret = get_reg(UART_REG_STATUS);
+ if (!(ret & UART_STATUS_DATAREADY))
+ return -1;
+ return get_reg(UART_REG_DATA) & UART_DATA_DATA;
+}
+
+static struct sbi_console_device gaisler_console = {
+ .name = "gaisler_uart",
+ .console_putc = gaisler_uart_putc,
+ .console_getc = gaisler_uart_getc
+};
+
+int gaisler_uart_init(unsigned long base, u32 in_freq, u32 baudrate)
+{
+ u32 ctrl;
+
+ uart_base = (volatile void *)base;
+
+ /* Configure baudrate */
+ if (in_freq)
+ set_reg(UART_REG_SCALER, in_freq / (baudrate * 8 + 7));
+
+ ctrl = get_reg(UART_REG_CTRL);
+ /* Preserve debug mode and flow control */
+ ctrl &= (UART_CTRL_DB | UART_CTRL_FL);
+ /* Enable TX and RX */
+ ctrl |= UART_CTRL_TE | UART_CTRL_RE;
+ set_reg(UART_REG_CTRL, ctrl);
+
+ sbi_console_set_device(&gaisler_console);
+
+ return 0;
+}
diff --git a/lib/utils/serial/objects.mk b/lib/utils/serial/objects.mk
index c0746f0..9fb0902 100644
--- a/lib/utils/serial/objects.mk
+++ b/lib/utils/serial/objects.mk
@@ -8,10 +8,12 @@
#
libsbiutils-objs-y += serial/fdt_serial.o
+libsbiutils-objs-y += serial/fdt_serial_gaisler.o
libsbiutils-objs-y += serial/fdt_serial_htif.o
libsbiutils-objs-y += serial/fdt_serial_shakti.o
libsbiutils-objs-y += serial/fdt_serial_sifive.o
libsbiutils-objs-y += serial/fdt_serial_uart8250.o
+libsbiutils-objs-y += serial/gaisler-uart.o
libsbiutils-objs-y += serial/shakti-uart.o
libsbiutils-objs-y += serial/sifive-uart.o
libsbiutils-objs-y += serial/uart8250.o
--
2.25.1
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