[PATCH v5 1/5] lib: utils: serial: Add Renesas SCIF driver
Anup Patel
anup at brainfault.org
Sat Dec 10 08:26:08 PST 2022
On Sat, Dec 10, 2022 at 4:00 PM Lad Prabhakar
<prabhakar.mahadev-lad.rj at bp.renesas.com> wrote:
>
> Add Renesas SCIF driver.
>
> Based on a patch in the BSP by Takeki Hamada
> <takeki.hamada.ak at bp.renesas.com>
> Link: https://github.com/renesas-rz/rz_opensbi/commits/work/OpenSBI-PMA
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj at bp.renesas.com>
Looks good to me.
Reviewed-by: Anup Patel <anup at brainfault.org>
Regards,
Anup
> ---
> v4->v5
> * No change
>
> v3->v4
> * Dropped returning from void func
> * Dropped unnecessary volatile variable
>
> v2->v3
> * Fixed review comments pointed by Bin
>
> RFC->v2
> * Fixed comments pointed by Xiang W
> ---
> include/sbi_utils/serial/renesas-scif.h | 11 +++
> lib/utils/serial/Kconfig | 4 +
> lib/utils/serial/objects.mk | 1 +
> lib/utils/serial/renesas_scif.c | 116 ++++++++++++++++++++++++
> 4 files changed, 132 insertions(+)
> create mode 100644 include/sbi_utils/serial/renesas-scif.h
> create mode 100644 lib/utils/serial/renesas_scif.c
>
> diff --git a/include/sbi_utils/serial/renesas-scif.h b/include/sbi_utils/serial/renesas-scif.h
> new file mode 100644
> index 0000000..0002a1a
> --- /dev/null
> +++ b/include/sbi_utils/serial/renesas-scif.h
> @@ -0,0 +1,11 @@
> +/* SPDX-License-Identifier: BSD-2-Clause */
> +/*
> + * Copyright (C) 2022 Renesas Electronics Corporation
> + */
> +
> +#ifndef __SERIAL_RENESAS_SCIF_H__
> +#define __SERIAL_RENESAS_SCIF_H__
> +
> +int renesas_scif_init(unsigned long base, u32 in_freq, u32 baudrate);
> +
> +#endif /* __SERIAL_RENESAS_SCIF_H__ */
> diff --git a/lib/utils/serial/Kconfig b/lib/utils/serial/Kconfig
> index da549a7..f6ed803 100644
> --- a/lib/utils/serial/Kconfig
> +++ b/lib/utils/serial/Kconfig
> @@ -59,6 +59,10 @@ config SERIAL_GAISLER
> bool "Gaisler UART support"
> default n
>
> +config SERIAL_RENESAS_SCIF
> + bool "Renesas SCIF support"
> + default n
> +
> config SERIAL_SHAKTI
> bool "Shakti UART support"
> default n
> diff --git a/lib/utils/serial/objects.mk b/lib/utils/serial/objects.mk
> index 98f3f9a..6520424 100644
> --- a/lib/utils/serial/objects.mk
> +++ b/lib/utils/serial/objects.mk
> @@ -36,6 +36,7 @@ libsbiutils-objs-$(CONFIG_FDT_SERIAL_XILINX_UARTLITE) += serial/fdt_serial_xlnx_
>
> libsbiutils-objs-$(CONFIG_SERIAL_CADENCE) += serial/cadence-uart.o
> libsbiutils-objs-$(CONFIG_SERIAL_GAISLER) += serial/gaisler-uart.o
> +libsbiutils-objs-$(CONFIG_SERIAL_RENESAS_SCIF) += serial/renesas_scif.o
> libsbiutils-objs-$(CONFIG_SERIAL_SHAKTI) += serial/shakti-uart.o
> libsbiutils-objs-$(CONFIG_SERIAL_SIFIVE) += serial/sifive-uart.o
> libsbiutils-objs-$(CONFIG_SERIAL_LITEX) += serial/litex-uart.o
> diff --git a/lib/utils/serial/renesas_scif.c b/lib/utils/serial/renesas_scif.c
> new file mode 100644
> index 0000000..cbe9db4
> --- /dev/null
> +++ b/lib/utils/serial/renesas_scif.c
> @@ -0,0 +1,116 @@
> +// SPDX-License-Identifier: BSD-2-Clause
> +/*
> + * Copyright (C) 2022 Renesas Electronics Corporation
> + */
> +
> +#include <sbi/riscv_io.h>
> +#include <sbi/sbi_console.h>
> +#include <sbi/sbi_timer.h>
> +#include <sbi_utils/serial/renesas-scif.h>
> +
> +/* clang-format off */
> +
> +#define SCIF_REG_SMR 0x0
> +#define SCIF_REG_BRR 0x2
> +#define SCIF_REG_SCR 0x4
> +#define SCIF_REG_FTDR 0x6
> +#define SCIF_REG_FSR 0x8
> +#define SCIF_REG_FCR 0xc
> +#define SCIF_REG_LSR 0x12
> +#define SCIF_REG_SEMR 0x14
> +
> +#define SCIF_FCR_RFRST 0x2 /* Reset assert receive-FIFO (bit[1]) */
> +#define SCIF_FCR_TFRST 0x4 /* Reset assert transmit-FIFO(bit[2]) */
> +
> +#define SCIF_FCR_RST_ASSRT_RFTF (SCIF_FCR_RFRST | SCIF_FCR_TFRST) /* Reset assert tx-FIFO & rx-FIFO */
> +#define SCIF_FCR_RST_NGATE_RFTF 0x0 /* Reset negate tx-FIFO & rx-FIFO */
> +
> +#define SCIF_SCR_RE 0x10 /* Enable receive (bit[4]) */
> +#define SCIF_SCR_TE 0x20 /* Enable transmit(bit[5]) */
> +#define SCIF_SCR_RCV_TRN_EN (SCIF_SCR_RE | SCIF_SCR_TE) /* Enable receive & transmit */
> +#define SCIF_SCR_RCV_TRN_DIS 0x0 /* Disable receive & transmit */
> +
> +#define SCIF_FSR_ER 0x80 /* Receive error flag */
> +#define SCIF_FSR_TEND 0x40 /* Transmit End Flag */
> +#define SCIF_FSR_TDFE 0x20 /* Transmit FIFO Data Empty Flag */
> +#define SCIF_FSR_BRK 0x10 /* Detect break flag */
> +#define SCIF_FSR_DR 0x1 /* Receive data ready flag */
> +
> +#define SCIF_FSR_TXD_CHK (SCIF_FSR_TEND | SCIF_FSR_TDFE)
> +
> +#define SCIF_SEMR_MDDRS 0x10 /* MDDR access enable */
> +
> +#define SCIF_REG_8BIT(reg) ((reg == SCIF_REG_BRR) || \
> + (reg == SCIF_REG_FTDR) || \
> + (reg == SCIF_REG_SEMR))
> +
> +#define SCBRR_VALUE(clk, baudrate) ((clk) / (32 * (baudrate)) - 1)
> +
> +/* clang-format on */
> +
> +static volatile char *scif_base;
> +
> +static u32 get_reg(u32 offset)
> +{
> + if (SCIF_REG_8BIT(offset))
> + return readb(scif_base + offset);
> +
> + return readw(scif_base + offset);
> +}
> +
> +static void set_reg(u32 offset, u32 val)
> +{
> + if (SCIF_REG_8BIT(offset))
> + writeb(val, scif_base + offset);
> + else
> + writew(val, scif_base + offset);
> +}
> +
> +static void renesas_scif_putc(char ch)
> +{
> + uint16_t reg;
> +
> + while (!(SCIF_FSR_TXD_CHK & get_reg(SCIF_REG_FSR)))
> + ;
> +
> + set_reg(SCIF_REG_FTDR, ch);
> + reg = get_reg(SCIF_REG_FSR);
> + reg &= ~SCIF_FSR_TXD_CHK;
> + set_reg(SCIF_REG_FSR, reg);
> +}
> +
> +static struct sbi_console_device renesas_scif_console = {
> + .name = "renesas_scif",
> + .console_putc = renesas_scif_putc,
> +};
> +
> +int renesas_scif_init(unsigned long base, u32 in_freq, u32 baudrate)
> +{
> + uint16_t data16;
> +
> + scif_base = (volatile char *)base;
> +
> + set_reg(SCIF_REG_SCR, SCIF_SCR_RCV_TRN_DIS);
> + set_reg(SCIF_REG_FCR, SCIF_FCR_RST_ASSRT_RFTF);
> +
> + data16 = get_reg(SCIF_REG_FSR); /* Dummy read */
> + set_reg(SCIF_REG_FSR, 0x0); /* Clear all error bit */
> +
> + data16 = get_reg(SCIF_REG_LSR); /* Dummy read */
> + set_reg(SCIF_REG_LSR, 0x0); /* Clear ORER bit */
> +
> + set_reg(SCIF_REG_SCR, 0x0);
> +
> + set_reg(SCIF_REG_SMR, 0x0);
> +
> + data16 = get_reg(SCIF_REG_SEMR);
> + set_reg(SCIF_REG_SEMR, data16 & (~SCIF_SEMR_MDDRS));
> + set_reg(SCIF_REG_BRR, SCBRR_VALUE(in_freq, baudrate));
> +
> + set_reg(SCIF_REG_FCR, SCIF_FCR_RST_NGATE_RFTF);
> + set_reg(SCIF_REG_SCR, SCIF_SCR_RCV_TRN_EN);
> +
> + sbi_console_set_device(&renesas_scif_console);
> +
> + return 0;
> +}
> --
> 2.17.1
>
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