[PATCH 1/1] lib: utils/serial: Add support for Gaisler APBUART
Anup Patel
Anup.Patel at wdc.com
Tue May 4 04:45:58 BST 2021
> -----Original Message-----
> From: opensbi <opensbi-bounces at lists.infradead.org> On Behalf Of Daniel
> Cederman
> Sent: 30 April 2021 12:06
> To: opensbi at lists.infradead.org
> Cc: daniel at gaisler.com
> Subject: [PATCH 1/1] lib: utils/serial: Add support for Gaisler APBUART
>
> 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>
Looks good to me.
Reviewed-by: Anup Patel <anup.patel at wdc.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" },
We do have compatible strings in OpenSBI which are not standardized by
Linux DT bindings so this compatible string is okay for now.
It is very important that whenever Linux DT bindings are accepted, we
add the accepted compatible string here as well.
Regards,
Anup
> + {},
> +};
> +
> +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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