| Message ID | 20220817154056.543158-1-junliang.tan@linux.starfivetech.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v4] lib: utils: serial: Add Cadence UART driver | expand |
On Wed, Aug 17, 2022 at 11:40:56PM +0800, Jun Liang Tan wrote: > Add Cadence UART driver > > Signed-off-by: Jun Liang Tan <junliang.tan@linux.starfivetech.com> > Signed-off-by: Wei Liang Lim <weiliang.lim@linux.starfivetech.com> > --- > > Changes in v4: > - Add changelog > - Check for possible divide-by-zero in uart_min_clk_divisor() by > referring to the fix in commit f27203525aa2fc20d0074feb892a6f8433f84e3a > - Cosmetic changes > > Changes in v3: > - Place #define register name in ascending order of register offset > - Change #define register name to match manual register name > - #define register flags in a way associate with their register > - Cosmetic changes > > Changes in v2: > - Rename fdt_parse_uart8250_node() to fdt_parse_uart_node() and make > neccessary changes in functions that call it > - Align patch with the latest OpenSBI sources > > include/sbi_utils/fdt/fdt_helper.h | 4 +- > include/sbi_utils/serial/cadence-uart.h | 16 +++ > lib/utils/fdt/fdt_helper.c | 6 +- > lib/utils/serial/Kconfig | 9 ++ > lib/utils/serial/cadence-uart.c | 128 ++++++++++++++++++++++++ > lib/utils/serial/fdt_serial_cadence.c | 35 +++++++ > lib/utils/serial/fdt_serial_uart8250.c | 2 +- > lib/utils/serial/objects.mk | 4 + > platform/generic/configs/defconfig | 1 + > 9 files changed, 199 insertions(+), 6 deletions(-) > create mode 100644 include/sbi_utils/serial/cadence-uart.h > create mode 100644 lib/utils/serial/cadence-uart.c > create mode 100644 lib/utils/serial/fdt_serial_cadence.c > Looks good! Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
在 2022-08-17星期三的 23:40 +0800，Jun Liang Tan写道： > Add Cadence UART driver > > Signed-off-by: Jun Liang Tan <junliang.tan@linux.starfivetech.com> > Signed-off-by: Wei Liang Lim <weiliang.lim@linux.starfivetech.com> > --- > > Changes in v4: > - Add changelog > - Check for possible divide-by-zero in uart_min_clk_divisor() by > referring to the fix in commit f27203525aa2fc20d0074feb892a6f8433f84e3a > - Cosmetic changes > > Changes in v3: > - Place #define register name in ascending order of register offset > - Change #define register name to match manual register name > - #define register flags in a way associate with their register > - Cosmetic changes > > Changes in v2: > - Rename fdt_parse_uart8250_node() to fdt_parse_uart_node() and make > neccessary changes in functions that call it > - Align patch with the latest OpenSBI sources > > include/sbi_utils/fdt/fdt_helper.h | 4 +- > include/sbi_utils/serial/cadence-uart.h | 16 +++ > lib/utils/fdt/fdt_helper.c | 6 +- > lib/utils/serial/Kconfig | 9 ++ > lib/utils/serial/cadence-uart.c | 128 ++++++++++++++++++++++++ > lib/utils/serial/fdt_serial_cadence.c | 35 +++++++ > lib/utils/serial/fdt_serial_uart8250.c | 2 +- > lib/utils/serial/objects.mk | 4 + > platform/generic/configs/defconfig | 1 + > 9 files changed, 199 insertions(+), 6 deletions(-) > create mode 100644 include/sbi_utils/serial/cadence-uart.h > create mode 100644 lib/utils/serial/cadence-uart.c > create mode 100644 lib/utils/serial/fdt_serial_cadence.c > > diff --git a/include/sbi_utils/fdt/fdt_helper.h b/include/sbi_utils/fdt/fdt_helper.h > index c60af35..bcd4996 100644 > --- a/include/sbi_utils/fdt/fdt_helper.h > +++ b/include/sbi_utils/fdt/fdt_helper.h > @@ -65,8 +65,8 @@ int fdt_parse_shakti_uart_node(void *fdt, int nodeoffset, > int fdt_parse_sifive_uart_node(void *fdt, int nodeoffset, > struct platform_uart_data *uart); > > -int fdt_parse_uart8250_node(void *fdt, int nodeoffset, > - struct platform_uart_data *uart); > +int fdt_parse_uart_node(void *fdt, int nodeoffset, > + struct platform_uart_data *uart); > > int fdt_parse_uart8250(void *fdt, struct platform_uart_data *uart, > const char *compatible); > diff --git a/include/sbi_utils/serial/cadence-uart.h b/include/sbi_utils/serial/cadence-uart.h > new file mode 100644 > index 0000000..e75fb95 > --- /dev/null > +++ b/include/sbi_utils/serial/cadence-uart.h > @@ -0,0 +1,16 @@ > +/* > + * SPDX-License-Identifier: BSD-2-Clause > + * > + * Copyright (c) 2022 StarFive Technology Co., Ltd. > + * > + * Author: Jun Liang Tan <junliang.tan@linux.starfivetech.com> > + */ > + > +#ifndef __SERIAL_CADENCE_UART_H__ > +#define __SERIAL_CADENCE_UART_H__ > + > +#include <sbi/sbi_types.h> > + > +int cadence_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 c6abf80..6a75d6f 100644 > --- a/lib/utils/fdt/fdt_helper.c > +++ b/lib/utils/fdt/fdt_helper.c > @@ -401,8 +401,8 @@ int fdt_parse_sifive_uart_node(void *fdt, int nodeoffset, > return 0; > } > > -int fdt_parse_uart8250_node(void *fdt, int nodeoffset, > - struct platform_uart_data *uart) > +int fdt_parse_uart_node(void *fdt, int nodeoffset, > + struct platform_uart_data *uart) > { > int len, rc; > const fdt32_t *val; > @@ -447,7 +447,7 @@ int fdt_parse_uart8250(void *fdt, struct platform_uart_data *uart, > if (nodeoffset < 0) > return nodeoffset; > > - return fdt_parse_uart8250_node(fdt, nodeoffset, uart); > + return fdt_parse_uart_node(fdt, nodeoffset, uart); > } > > int fdt_parse_xlnx_uartlite_node(void *fdt, int nodeoffset, > diff --git a/lib/utils/serial/Kconfig b/lib/utils/serial/Kconfig > index 152060d..6e425f2 100644 > --- a/lib/utils/serial/Kconfig > +++ b/lib/utils/serial/Kconfig > @@ -9,6 +9,11 @@ config FDT_SERIAL > > if FDT_SERIAL > > +config FDT_SERIAL_CADENCE > + bool "Cadence UART FDT driver" > + select SERIAL_CADENCE > + default n > + > config FDT_SERIAL_GAISLER > bool "Gaisler UART FDT driver" > select SERIAL_GAISLER > @@ -46,6 +51,10 @@ config FDT_SERIAL_XILINX_UARTLITE > > endif > > +config SERIAL_CADENCE > + bool "Cadence UART support" > + default n > + > config SERIAL_GAISLER > bool "Gaisler UART support" > default n > diff --git a/lib/utils/serial/cadence-uart.c b/lib/utils/serial/cadence-uart.c > new file mode 100644 > index 0000000..8a2b6ba > --- /dev/null > +++ b/lib/utils/serial/cadence-uart.c > @@ -0,0 +1,128 @@ > +/* > + * SPDX-License-Identifier: BSD-2-Clause > + * > + * Copyright (c) 2022 StarFive Technology Co., Ltd. > + * > + * Author: Jun Liang Tan <junliang.tan@linux.starfivetech.com> > + */ > + > +#include <sbi/riscv_io.h> > +#include <sbi/sbi_console.h> > +#include <sbi_utils/serial/cadence-uart.h> > + > +/* clang-format off */ > + > +#define UART_REG_CTRL 0x00 > +#define UART_REG_MODE 0x04 > +#define UART_REG_IDR 0x0C > +#define UART_REG_BRGR 0x18 > +#define UART_REG_CSR 0x2C > +#define UART_REG_RFIFO_TFIFO 0x30 > +#define UART_REG_BDIVR 0x34 > + > +#define UART_CTRL_RXRES 0x00000001 > +#define UART_CTRL_TXRES 0x00000002 > +#define UART_CTRL_RXEN 0x00000004 > +#define UART_CTRL_RXDIS 0x00000008 > +#define UART_CTRL_TXEN 0x00000010 > +#define UART_CTRL_TXDIS 0x00000020 > + > +#define UART_MODE_PAR_NONE 0x00000020 /* No parity set */ > + > +#define UART_BRGR_CD_CLKDIVISOR 0x00000001 /* baud_sample = sel_clk */ > + > +#define UART_CSR_REMPTY 0x00000002 > +#define UART_CSR_TFUL 0x00000010 > + > +/* clang-format on */ > + > +static volatile void *uart_base; > +static u32 uart_in_freq; > +static u32 uart_baudrate; > + > +/* > + * Find minimum divisor divides in_freq to max_target_hz; > + * Based on SiFive UART driver (sifive-uart.c) > + */ > +static inline unsigned int uart_min_clk_divisor(uint64_t in_freq, > + uint64_t max_target_hz) > +{ > + uint64_t quotient = (in_freq + max_target_hz - 1) / (max_target_hz); > + > + /* Avoid underflow */ > + if (quotient == 0) > + return 0; > + else > + return quotient - 1; > +} The default of integer division in C language is to discard the fractional part. So, the above code is equivalent to: static inline unsigned int uart_min_clk_divisor(uint64_t in_freq, uint64_t max_target_hz) { return in_freq / max_target_hz; } Regards, Xiang W > + > +static u32 get_reg(u32 offset) > +{ > + return readl(uart_base + offset); > +} > + > +static void set_reg(u32 offset, u32 val) > +{ > + writel(val, uart_base + offset); > +} > + > +static void cadence_uart_putc(char ch) > +{ > + while (get_reg(UART_REG_CSR) & UART_CSR_TFUL) > + ; > + > + set_reg(UART_REG_RFIFO_TFIFO, ch); > +} > + > +static int cadence_uart_getc(void) > +{ > + u32 ret = get_reg(UART_REG_CSR); > + > + if (!(ret & UART_CSR_REMPTY)) > + return get_reg(UART_REG_RFIFO_TFIFO); > + > + return -1; > +} > + > +static struct sbi_console_device cadence_console = { > + .name = "cadence_uart", > + .console_putc = cadence_uart_putc, > + .console_getc = cadence_uart_getc > +}; > + > +int cadence_uart_init(unsigned long base, u32 in_freq, u32 baudrate) > +{ > + uart_base = (volatile void *)base; > + uart_in_freq = in_freq; > + uart_baudrate = baudrate; > + > + /* Disable interrupts */ > + set_reg(UART_REG_IDR, 0xFFFFFFFF); > + > + /* Disable TX RX */ > + set_reg(UART_REG_CTRL, UART_CTRL_TXDIS | UART_CTRL_RXDIS); > + > + /* Configure baudrate */ > + if (in_freq && baudrate) { > + set_reg(UART_REG_BRGR, UART_BRGR_CD_CLKDIVISOR); > + set_reg(UART_REG_BDIVR, > + uart_min_clk_divisor(in_freq, baudrate)); > + } > + > + /* Software reset TX RX data path and enable TX RX */ > + set_reg(UART_REG_CTRL, UART_CTRL_TXRES | UART_CTRL_RXRES > + | UART_CTRL_TXEN | UART_CTRL_RXEN); > + > + /* > + * Set: > + * 1 stop bit, bits[07:06] = 0x00, > + * no parity set, bits[05:03] = 0x100, > + * 8 bits character length, bits[02:01] = 0x00, > + * sel_clk = uart_clk, bit[0] = 0x0 > + */ > + set_reg(UART_REG_MODE, UART_MODE_PAR_NONE); > + > + sbi_console_set_device(&cadence_console); > + > + return 0; > +} > diff --git a/lib/utils/serial/fdt_serial_cadence.c b/lib/utils/serial/fdt_serial_cadence.c > new file mode 100644 > index 0000000..946e533 > --- /dev/null > +++ b/lib/utils/serial/fdt_serial_cadence.c > @@ -0,0 +1,35 @@ > +/* > + * SPDX-License-Identifier: BSD-2-Clause > + * > + * Copyright (c) 2022 StarFive Technology Co., Ltd. > + * > + * Author: Jun Liang Tan <junliang.tan@linux.starfivetech.com> > + */ > + > +#include <sbi_utils/fdt/fdt_helper.h> > +#include <sbi_utils/serial/fdt_serial.h> > +#include <sbi_utils/serial/cadence-uart.h> > + > +static int serial_cadence_init(void *fdt, int nodeoff, > + const struct fdt_match *match) > +{ > + int rc; > + struct platform_uart_data uart = { 0 }; > + > + rc = fdt_parse_uart_node(fdt, nodeoff, &uart); > + if (rc) > + return rc; > + > + return cadence_uart_init(uart.addr, uart.freq, uart.baud); > +} > + > +static const struct fdt_match serial_cadence_match[] = { > + { .compatible = "cdns,uart-r1p12" }, > + { .compatible = "starfive,jh8100-uart" }, > + { }, > +}; > + > +struct fdt_serial fdt_serial_cadence = { > + .match_table = serial_cadence_match, > + .init = serial_cadence_init > +}; > diff --git a/lib/utils/serial/fdt_serial_uart8250.c b/lib/utils/serial/fdt_serial_uart8250.c > index 0b95f2d..7b5d6a4 100644 > --- a/lib/utils/serial/fdt_serial_uart8250.c > +++ b/lib/utils/serial/fdt_serial_uart8250.c > @@ -17,7 +17,7 @@ static int serial_uart8250_init(void *fdt, int nodeoff, > int rc; > struct platform_uart_data uart = { 0 }; > > - rc = fdt_parse_uart8250_node(fdt, nodeoff, &uart); > + rc = fdt_parse_uart_node(fdt, nodeoff, &uart); > if (rc) > return rc; > > diff --git a/lib/utils/serial/objects.mk b/lib/utils/serial/objects.mk > index fa9f5a3..efb1d9e 100644 > --- a/lib/utils/serial/objects.mk > +++ b/lib/utils/serial/objects.mk > @@ -10,6 +10,9 @@ > libsbiutils-objs-$(CONFIG_FDT_SERIAL) += serial/fdt_serial.o > libsbiutils-objs-$(CONFIG_FDT_SERIAL) += serial/fdt_serial_drivers.o > > +carray-fdt_serial_drivers-$(CONFIG_FDT_SERIAL_CADENCE) += fdt_serial_cadence > +libsbiutils-objs-$(CONFIG_FDT_SERIAL_CADENCE) += serial/fdt_serial_cadence.o > + > carray-fdt_serial_drivers-$(CONFIG_FDT_SERIAL_GAISLER) += fdt_serial_gaisler > libsbiutils-objs-$(CONFIG_FDT_SERIAL_GAISLER) += serial/fdt_serial_gaisler.o > > @@ -31,6 +34,7 @@ libsbiutils-objs-$(CONFIG_FDT_SERIAL_UART8250) += serial/fdt_serial_uart8250.o > carray-fdt_serial_drivers-$(CONFIG_FDT_SERIAL_XILINX_UARTLITE) += fdt_serial_xlnx_uartlite > libsbiutils-objs-$(CONFIG_FDT_SERIAL_XILINX_UARTLITE) += serial/fdt_serial_xlnx_uartlite.o > > +libsbiutils-objs-$(CONFIG_SERIAL_CADENCE) += serial/cadence-uart.o > libsbiutils-objs-$(CONFIG_SERIAL_GAISLER) += serial/gaisler-uart.o > libsbiutils-objs-$(CONFIG_SERIAL_SHAKTI) += serial/shakti-uart.o > libsbiutils-objs-$(CONFIG_SERIAL_SIFIVE) += serial/sifive-uart.o > diff --git a/platform/generic/configs/defconfig b/platform/generic/configs/defconfig > index 2a75394..e324173 100644 > --- a/platform/generic/configs/defconfig > +++ b/platform/generic/configs/defconfig > @@ -18,6 +18,7 @@ CONFIG_FDT_RESET_SIFIVE_TEST=y > CONFIG_FDT_RESET_SUNXI_WDT=y > CONFIG_FDT_RESET_THEAD=y > CONFIG_FDT_SERIAL=y > +CONFIG_FDT_SERIAL_CADENCE=y > CONFIG_FDT_SERIAL_GAISLER=y > CONFIG_FDT_SERIAL_HTIF=y > CONFIG_FDT_SERIAL_SHAKTI=y > -- > 2.37.1 > > >
On 18 Aug 2022, at 01:31, Xiang W <wxjstz@126.com> wrote: > > 在 2022-08-17星期三的 23:40 +0800，Jun Liang Tan写道： >> Add Cadence UART driver >> >> Signed-off-by: Jun Liang Tan <junliang.tan@linux.starfivetech.com> >> Signed-off-by: Wei Liang Lim <weiliang.lim@linux.starfivetech.com> >> --- >> >> Changes in v4: >> - Add changelog >> - Check for possible divide-by-zero in uart_min_clk_divisor() by >> referring to the fix in commit f27203525aa2fc20d0074feb892a6f8433f84e3a >> - Cosmetic changes >> >> Changes in v3: >> - Place #define register name in ascending order of register offset >> - Change #define register name to match manual register name >> - #define register flags in a way associate with their register >> - Cosmetic changes >> >> Changes in v2: >> - Rename fdt_parse_uart8250_node() to fdt_parse_uart_node() and make >> neccessary changes in functions that call it >> - Align patch with the latest OpenSBI sources >> >> include/sbi_utils/fdt/fdt_helper.h | 4 +- >> include/sbi_utils/serial/cadence-uart.h | 16 +++ >> lib/utils/fdt/fdt_helper.c | 6 +- >> lib/utils/serial/Kconfig | 9 ++ >> lib/utils/serial/cadence-uart.c | 128 ++++++++++++++++++++++++ >> lib/utils/serial/fdt_serial_cadence.c | 35 +++++++ >> lib/utils/serial/fdt_serial_uart8250.c | 2 +- >> lib/utils/serial/objects.mk | 4 + >> platform/generic/configs/defconfig | 1 + >> 9 files changed, 199 insertions(+), 6 deletions(-) >> create mode 100644 include/sbi_utils/serial/cadence-uart.h >> create mode 100644 lib/utils/serial/cadence-uart.c >> create mode 100644 lib/utils/serial/fdt_serial_cadence.c >> >> diff --git a/include/sbi_utils/fdt/fdt_helper.h b/include/sbi_utils/fdt/fdt_helper.h >> index c60af35..bcd4996 100644 >> --- a/include/sbi_utils/fdt/fdt_helper.h >> +++ b/include/sbi_utils/fdt/fdt_helper.h >> @@ -65,8 +65,8 @@ int fdt_parse_shakti_uart_node(void *fdt, int nodeoffset, >> int fdt_parse_sifive_uart_node(void *fdt, int nodeoffset, >> struct platform_uart_data *uart); >> >> -int fdt_parse_uart8250_node(void *fdt, int nodeoffset, >> - struct platform_uart_data *uart); >> +int fdt_parse_uart_node(void *fdt, int nodeoffset, >> + struct platform_uart_data *uart); >> >> int fdt_parse_uart8250(void *fdt, struct platform_uart_data *uart, >> const char *compatible); >> diff --git a/include/sbi_utils/serial/cadence-uart.h b/include/sbi_utils/serial/cadence-uart.h >> new file mode 100644 >> index 0000000..e75fb95 >> --- /dev/null >> +++ b/include/sbi_utils/serial/cadence-uart.h >> @@ -0,0 +1,16 @@ >> +/* >> + * SPDX-License-Identifier: BSD-2-Clause >> + * >> + * Copyright (c) 2022 StarFive Technology Co., Ltd. >> + * >> + * Author: Jun Liang Tan <junliang.tan@linux.starfivetech.com> >> + */ >> + >> +#ifndef __SERIAL_CADENCE_UART_H__ >> +#define __SERIAL_CADENCE_UART_H__ >> + >> +#include <sbi/sbi_types.h> >> + >> +int cadence_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 c6abf80..6a75d6f 100644 >> --- a/lib/utils/fdt/fdt_helper.c >> +++ b/lib/utils/fdt/fdt_helper.c >> @@ -401,8 +401,8 @@ int fdt_parse_sifive_uart_node(void *fdt, int nodeoffset, >> return 0; >> } >> >> -int fdt_parse_uart8250_node(void *fdt, int nodeoffset, >> - struct platform_uart_data *uart) >> +int fdt_parse_uart_node(void *fdt, int nodeoffset, >> + struct platform_uart_data *uart) >> { >> int len, rc; >> const fdt32_t *val; >> @@ -447,7 +447,7 @@ int fdt_parse_uart8250(void *fdt, struct platform_uart_data *uart, >> if (nodeoffset < 0) >> return nodeoffset; >> >> - return fdt_parse_uart8250_node(fdt, nodeoffset, uart); >> + return fdt_parse_uart_node(fdt, nodeoffset, uart); >> } >> >> int fdt_parse_xlnx_uartlite_node(void *fdt, int nodeoffset, >> diff --git a/lib/utils/serial/Kconfig b/lib/utils/serial/Kconfig >> index 152060d..6e425f2 100644 >> --- a/lib/utils/serial/Kconfig >> +++ b/lib/utils/serial/Kconfig >> @@ -9,6 +9,11 @@ config FDT_SERIAL >> >> if FDT_SERIAL >> >> +config FDT_SERIAL_CADENCE >> + bool "Cadence UART FDT driver" >> + select SERIAL_CADENCE >> + default n >> + >> config FDT_SERIAL_GAISLER >> bool "Gaisler UART FDT driver" >> select SERIAL_GAISLER >> @@ -46,6 +51,10 @@ config FDT_SERIAL_XILINX_UARTLITE >> >> endif >> >> +config SERIAL_CADENCE >> + bool "Cadence UART support" >> + default n >> + >> config SERIAL_GAISLER >> bool "Gaisler UART support" >> default n >> diff --git a/lib/utils/serial/cadence-uart.c b/lib/utils/serial/cadence-uart.c >> new file mode 100644 >> index 0000000..8a2b6ba >> --- /dev/null >> +++ b/lib/utils/serial/cadence-uart.c >> @@ -0,0 +1,128 @@ >> +/* >> + * SPDX-License-Identifier: BSD-2-Clause >> + * >> + * Copyright (c) 2022 StarFive Technology Co., Ltd. >> + * >> + * Author: Jun Liang Tan <junliang.tan@linux.starfivetech.com> >> + */ >> + >> +#include <sbi/riscv_io.h> >> +#include <sbi/sbi_console.h> >> +#include <sbi_utils/serial/cadence-uart.h> >> + >> +/* clang-format off */ >> + >> +#define UART_REG_CTRL 0x00 >> +#define UART_REG_MODE 0x04 >> +#define UART_REG_IDR 0x0C >> +#define UART_REG_BRGR 0x18 >> +#define UART_REG_CSR 0x2C >> +#define UART_REG_RFIFO_TFIFO 0x30 >> +#define UART_REG_BDIVR 0x34 >> + >> +#define UART_CTRL_RXRES 0x00000001 >> +#define UART_CTRL_TXRES 0x00000002 >> +#define UART_CTRL_RXEN 0x00000004 >> +#define UART_CTRL_RXDIS 0x00000008 >> +#define UART_CTRL_TXEN 0x00000010 >> +#define UART_CTRL_TXDIS 0x00000020 >> + >> +#define UART_MODE_PAR_NONE 0x00000020 /* No parity set */ >> + >> +#define UART_BRGR_CD_CLKDIVISOR 0x00000001 /* baud_sample = sel_clk */ >> + >> +#define UART_CSR_REMPTY 0x00000002 >> +#define UART_CSR_TFUL 0x00000010 >> + >> +/* clang-format on */ >> + >> +static volatile void *uart_base; >> +static u32 uart_in_freq; >> +static u32 uart_baudrate; >> + >> +/* >> + * Find minimum divisor divides in_freq to max_target_hz; >> + * Based on SiFive UART driver (sifive-uart.c) >> + */ >> +static inline unsigned int uart_min_clk_divisor(uint64_t in_freq, >> + uint64_t max_target_hz) >> +{ >> + uint64_t quotient = (in_freq + max_target_hz - 1) / (max_target_hz); >> + >> + /* Avoid underflow */ >> + if (quotient == 0) >> + return 0; >> + else >> + return quotient - 1; >> +} > > The default of integer division in C language is to discard the fractional part. > So, the above code is equivalent to: > > static inline unsigned int uart_min_clk_divisor(uint64_t in_freq, > uint64_t max_target_hz) > { > return in_freq / max_target_hz; > } Not if in_freq is a non-zero multiple of max_target_hz. I also assume the - 1 in the SiFive UART is a reflection of it biasing its divisor by 1. Does the Cadence UART actually do that too, or is this a copy/paste error? Jess > Regards, > Xiang W >> + >> +static u32 get_reg(u32 offset) >> +{ >> + return readl(uart_base + offset); >> +} >> + >> +static void set_reg(u32 offset, u32 val) >> +{ >> + writel(val, uart_base + offset); >> +} >> + >> +static void cadence_uart_putc(char ch) >> +{ >> + while (get_reg(UART_REG_CSR) & UART_CSR_TFUL) >> + ; >> + >> + set_reg(UART_REG_RFIFO_TFIFO, ch); >> +} >> + >> +static int cadence_uart_getc(void) >> +{ >> + u32 ret = get_reg(UART_REG_CSR); >> + >> + if (!(ret & UART_CSR_REMPTY)) >> + return get_reg(UART_REG_RFIFO_TFIFO); >> + >> + return -1; >> +} >> + >> +static struct sbi_console_device cadence_console = { >> + .name = "cadence_uart", >> + .console_putc = cadence_uart_putc, >> + .console_getc = cadence_uart_getc >> +}; >> + >> +int cadence_uart_init(unsigned long base, u32 in_freq, u32 baudrate) >> +{ >> + uart_base = (volatile void *)base; >> + uart_in_freq = in_freq; >> + uart_baudrate = baudrate; >> + >> + /* Disable interrupts */ >> + set_reg(UART_REG_IDR, 0xFFFFFFFF); >> + >> + /* Disable TX RX */ >> + set_reg(UART_REG_CTRL, UART_CTRL_TXDIS | UART_CTRL_RXDIS); >> + >> + /* Configure baudrate */ >> + if (in_freq && baudrate) { >> + set_reg(UART_REG_BRGR, UART_BRGR_CD_CLKDIVISOR); >> + set_reg(UART_REG_BDIVR, >> + uart_min_clk_divisor(in_freq, baudrate)); >> + } >> + >> + /* Software reset TX RX data path and enable TX RX */ >> + set_reg(UART_REG_CTRL, UART_CTRL_TXRES | UART_CTRL_RXRES >> + | UART_CTRL_TXEN | UART_CTRL_RXEN); >> + >> + /* >> + * Set: >> + * 1 stop bit, bits[07:06] = 0x00, >> + * no parity set, bits[05:03] = 0x100, >> + * 8 bits character length, bits[02:01] = 0x00, >> + * sel_clk = uart_clk, bit[0] = 0x0 >> + */ >> + set_reg(UART_REG_MODE, UART_MODE_PAR_NONE); >> + >> + sbi_console_set_device(&cadence_console); >> + >> + return 0; >> +} >> diff --git a/lib/utils/serial/fdt_serial_cadence.c b/lib/utils/serial/fdt_serial_cadence.c >> new file mode 100644 >> index 0000000..946e533 >> --- /dev/null >> +++ b/lib/utils/serial/fdt_serial_cadence.c >> @@ -0,0 +1,35 @@ >> +/* >> + * SPDX-License-Identifier: BSD-2-Clause >> + * >> + * Copyright (c) 2022 StarFive Technology Co., Ltd. >> + * >> + * Author: Jun Liang Tan <junliang.tan@linux.starfivetech.com> >> + */ >> + >> +#include <sbi_utils/fdt/fdt_helper.h> >> +#include <sbi_utils/serial/fdt_serial.h> >> +#include <sbi_utils/serial/cadence-uart.h> >> + >> +static int serial_cadence_init(void *fdt, int nodeoff, >> + const struct fdt_match *match) >> +{ >> + int rc; >> + struct platform_uart_data uart = { 0 }; >> + >> + rc = fdt_parse_uart_node(fdt, nodeoff, &uart); >> + if (rc) >> + return rc; >> + >> + return cadence_uart_init(uart.addr, uart.freq, uart.baud); >> +} >> + >> +static const struct fdt_match serial_cadence_match[] = { >> + { .compatible = "cdns,uart-r1p12" }, >> + { .compatible = "starfive,jh8100-uart" }, >> + { }, >> +}; >> + >> +struct fdt_serial fdt_serial_cadence = { >> + .match_table = serial_cadence_match, >> + .init = serial_cadence_init >> +}; >> diff --git a/lib/utils/serial/fdt_serial_uart8250.c b/lib/utils/serial/fdt_serial_uart8250.c >> index 0b95f2d..7b5d6a4 100644 >> --- a/lib/utils/serial/fdt_serial_uart8250.c >> +++ b/lib/utils/serial/fdt_serial_uart8250.c >> @@ -17,7 +17,7 @@ static int serial_uart8250_init(void *fdt, int nodeoff, >> int rc; >> struct platform_uart_data uart = { 0 }; >> >> - rc = fdt_parse_uart8250_node(fdt, nodeoff, &uart); >> + rc = fdt_parse_uart_node(fdt, nodeoff, &uart); >> if (rc) >> return rc; >> >> diff --git a/lib/utils/serial/objects.mk b/lib/utils/serial/objects.mk >> index fa9f5a3..efb1d9e 100644 >> --- a/lib/utils/serial/objects.mk >> +++ b/lib/utils/serial/objects.mk >> @@ -10,6 +10,9 @@ >> libsbiutils-objs-$(CONFIG_FDT_SERIAL) += serial/fdt_serial.o >> libsbiutils-objs-$(CONFIG_FDT_SERIAL) += serial/fdt_serial_drivers.o >> >> +carray-fdt_serial_drivers-$(CONFIG_FDT_SERIAL_CADENCE) += fdt_serial_cadence >> +libsbiutils-objs-$(CONFIG_FDT_SERIAL_CADENCE) += serial/fdt_serial_cadence.o >> + >> carray-fdt_serial_drivers-$(CONFIG_FDT_SERIAL_GAISLER) += fdt_serial_gaisler >> libsbiutils-objs-$(CONFIG_FDT_SERIAL_GAISLER) += serial/fdt_serial_gaisler.o >> >> @@ -31,6 +34,7 @@ libsbiutils-objs-$(CONFIG_FDT_SERIAL_UART8250) += serial/fdt_serial_uart8250.o >> carray-fdt_serial_drivers-$(CONFIG_FDT_SERIAL_XILINX_UARTLITE) += fdt_serial_xlnx_uartlite >> libsbiutils-objs-$(CONFIG_FDT_SERIAL_XILINX_UARTLITE) += serial/fdt_serial_xlnx_uartlite.o >> >> +libsbiutils-objs-$(CONFIG_SERIAL_CADENCE) += serial/cadence-uart.o >> libsbiutils-objs-$(CONFIG_SERIAL_GAISLER) += serial/gaisler-uart.o >> libsbiutils-objs-$(CONFIG_SERIAL_SHAKTI) += serial/shakti-uart.o >> libsbiutils-objs-$(CONFIG_SERIAL_SIFIVE) += serial/sifive-uart.o >> diff --git a/platform/generic/configs/defconfig b/platform/generic/configs/defconfig >> index 2a75394..e324173 100644 >> --- a/platform/generic/configs/defconfig >> +++ b/platform/generic/configs/defconfig >> @@ -18,6 +18,7 @@ CONFIG_FDT_RESET_SIFIVE_TEST=y >> CONFIG_FDT_RESET_SUNXI_WDT=y >> CONFIG_FDT_RESET_THEAD=y >> CONFIG_FDT_SERIAL=y >> +CONFIG_FDT_SERIAL_CADENCE=y >> CONFIG_FDT_SERIAL_GAISLER=y >> CONFIG_FDT_SERIAL_HTIF=y >> CONFIG_FDT_SERIAL_SHAKTI=y >> -- >> 2.37.1 >> >> >> > > > > -- > opensbi mailing list > opensbi@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/opensbi
On Wed, Aug 17, 2022 at 9:11 PM Jun Liang Tan <junliang.tan@linux.starfivetech.com> wrote: > > Add Cadence UART driver > > Signed-off-by: Jun Liang Tan <junliang.tan@linux.starfivetech.com> > Signed-off-by: Wei Liang Lim <weiliang.lim@linux.starfivetech.com> Overall, this looks good except the divide-by-zero question raised by other folks in uart_min_clk_divisor(). Reviewed-by: Anup Patel <anup@brainfault.org> Regards, Anup > --- > > Changes in v4: > - Add changelog > - Check for possible divide-by-zero in uart_min_clk_divisor() by > referring to the fix in commit f27203525aa2fc20d0074feb892a6f8433f84e3a > - Cosmetic changes > > Changes in v3: > - Place #define register name in ascending order of register offset > - Change #define register name to match manual register name > - #define register flags in a way associate with their register > - Cosmetic changes > > Changes in v2: > - Rename fdt_parse_uart8250_node() to fdt_parse_uart_node() and make > neccessary changes in functions that call it > - Align patch with the latest OpenSBI sources > > include/sbi_utils/fdt/fdt_helper.h | 4 +- > include/sbi_utils/serial/cadence-uart.h | 16 +++ > lib/utils/fdt/fdt_helper.c | 6 +- > lib/utils/serial/Kconfig | 9 ++ > lib/utils/serial/cadence-uart.c | 128 ++++++++++++++++++++++++ > lib/utils/serial/fdt_serial_cadence.c | 35 +++++++ > lib/utils/serial/fdt_serial_uart8250.c | 2 +- > lib/utils/serial/objects.mk | 4 + > platform/generic/configs/defconfig | 1 + > 9 files changed, 199 insertions(+), 6 deletions(-) > create mode 100644 include/sbi_utils/serial/cadence-uart.h > create mode 100644 lib/utils/serial/cadence-uart.c > create mode 100644 lib/utils/serial/fdt_serial_cadence.c > > diff --git a/include/sbi_utils/fdt/fdt_helper.h b/include/sbi_utils/fdt/fdt_helper.h > index c60af35..bcd4996 100644 > --- a/include/sbi_utils/fdt/fdt_helper.h > +++ b/include/sbi_utils/fdt/fdt_helper.h > @@ -65,8 +65,8 @@ int fdt_parse_shakti_uart_node(void *fdt, int nodeoffset, > int fdt_parse_sifive_uart_node(void *fdt, int nodeoffset, > struct platform_uart_data *uart); > > -int fdt_parse_uart8250_node(void *fdt, int nodeoffset, > - struct platform_uart_data *uart); > +int fdt_parse_uart_node(void *fdt, int nodeoffset, > + struct platform_uart_data *uart); > > int fdt_parse_uart8250(void *fdt, struct platform_uart_data *uart, > const char *compatible); > diff --git a/include/sbi_utils/serial/cadence-uart.h b/include/sbi_utils/serial/cadence-uart.h > new file mode 100644 > index 0000000..e75fb95 > --- /dev/null > +++ b/include/sbi_utils/serial/cadence-uart.h > @@ -0,0 +1,16 @@ > +/* > + * SPDX-License-Identifier: BSD-2-Clause > + * > + * Copyright (c) 2022 StarFive Technology Co., Ltd. > + * > + * Author: Jun Liang Tan <junliang.tan@linux.starfivetech.com> > + */ > + > +#ifndef __SERIAL_CADENCE_UART_H__ > +#define __SERIAL_CADENCE_UART_H__ > + > +#include <sbi/sbi_types.h> > + > +int cadence_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 c6abf80..6a75d6f 100644 > --- a/lib/utils/fdt/fdt_helper.c > +++ b/lib/utils/fdt/fdt_helper.c > @@ -401,8 +401,8 @@ int fdt_parse_sifive_uart_node(void *fdt, int nodeoffset, > return 0; > } > > -int fdt_parse_uart8250_node(void *fdt, int nodeoffset, > - struct platform_uart_data *uart) > +int fdt_parse_uart_node(void *fdt, int nodeoffset, > + struct platform_uart_data *uart) > { > int len, rc; > const fdt32_t *val; > @@ -447,7 +447,7 @@ int fdt_parse_uart8250(void *fdt, struct platform_uart_data *uart, > if (nodeoffset < 0) > return nodeoffset; > > - return fdt_parse_uart8250_node(fdt, nodeoffset, uart); > + return fdt_parse_uart_node(fdt, nodeoffset, uart); > } > > int fdt_parse_xlnx_uartlite_node(void *fdt, int nodeoffset, > diff --git a/lib/utils/serial/Kconfig b/lib/utils/serial/Kconfig > index 152060d..6e425f2 100644 > --- a/lib/utils/serial/Kconfig > +++ b/lib/utils/serial/Kconfig > @@ -9,6 +9,11 @@ config FDT_SERIAL > > if FDT_SERIAL > > +config FDT_SERIAL_CADENCE > + bool "Cadence UART FDT driver" > + select SERIAL_CADENCE > + default n > + > config FDT_SERIAL_GAISLER > bool "Gaisler UART FDT driver" > select SERIAL_GAISLER > @@ -46,6 +51,10 @@ config FDT_SERIAL_XILINX_UARTLITE > > endif > > +config SERIAL_CADENCE > + bool "Cadence UART support" > + default n > + > config SERIAL_GAISLER > bool "Gaisler UART support" > default n > diff --git a/lib/utils/serial/cadence-uart.c b/lib/utils/serial/cadence-uart.c > new file mode 100644 > index 0000000..8a2b6ba > --- /dev/null > +++ b/lib/utils/serial/cadence-uart.c > @@ -0,0 +1,128 @@ > +/* > + * SPDX-License-Identifier: BSD-2-Clause > + * > + * Copyright (c) 2022 StarFive Technology Co., Ltd. > + * > + * Author: Jun Liang Tan <junliang.tan@linux.starfivetech.com> > + */ > + > +#include <sbi/riscv_io.h> > +#include <sbi/sbi_console.h> > +#include <sbi_utils/serial/cadence-uart.h> > + > +/* clang-format off */ > + > +#define UART_REG_CTRL 0x00 > +#define UART_REG_MODE 0x04 > +#define UART_REG_IDR 0x0C > +#define UART_REG_BRGR 0x18 > +#define UART_REG_CSR 0x2C > +#define UART_REG_RFIFO_TFIFO 0x30 > +#define UART_REG_BDIVR 0x34 > + > +#define UART_CTRL_RXRES 0x00000001 > +#define UART_CTRL_TXRES 0x00000002 > +#define UART_CTRL_RXEN 0x00000004 > +#define UART_CTRL_RXDIS 0x00000008 > +#define UART_CTRL_TXEN 0x00000010 > +#define UART_CTRL_TXDIS 0x00000020 > + > +#define UART_MODE_PAR_NONE 0x00000020 /* No parity set */ > + > +#define UART_BRGR_CD_CLKDIVISOR 0x00000001 /* baud_sample = sel_clk */ > + > +#define UART_CSR_REMPTY 0x00000002 > +#define UART_CSR_TFUL 0x00000010 > + > +/* clang-format on */ > + > +static volatile void *uart_base; > +static u32 uart_in_freq; > +static u32 uart_baudrate; > + > +/* > + * Find minimum divisor divides in_freq to max_target_hz; > + * Based on SiFive UART driver (sifive-uart.c) > + */ > +static inline unsigned int uart_min_clk_divisor(uint64_t in_freq, > + uint64_t max_target_hz) > +{ > + uint64_t quotient = (in_freq + max_target_hz - 1) / (max_target_hz); > + > + /* Avoid underflow */ > + if (quotient == 0) > + return 0; > + else > + return quotient - 1; > +} > + > +static u32 get_reg(u32 offset) > +{ > + return readl(uart_base + offset); > +} > + > +static void set_reg(u32 offset, u32 val) > +{ > + writel(val, uart_base + offset); > +} > + > +static void cadence_uart_putc(char ch) > +{ > + while (get_reg(UART_REG_CSR) & UART_CSR_TFUL) > + ; > + > + set_reg(UART_REG_RFIFO_TFIFO, ch); > +} > + > +static int cadence_uart_getc(void) > +{ > + u32 ret = get_reg(UART_REG_CSR); > + > + if (!(ret & UART_CSR_REMPTY)) > + return get_reg(UART_REG_RFIFO_TFIFO); > + > + return -1; > +} > + > +static struct sbi_console_device cadence_console = { > + .name = "cadence_uart", > + .console_putc = cadence_uart_putc, > + .console_getc = cadence_uart_getc > +}; > + > +int cadence_uart_init(unsigned long base, u32 in_freq, u32 baudrate) > +{ > + uart_base = (volatile void *)base; > + uart_in_freq = in_freq; > + uart_baudrate = baudrate; > + > + /* Disable interrupts */ > + set_reg(UART_REG_IDR, 0xFFFFFFFF); > + > + /* Disable TX RX */ > + set_reg(UART_REG_CTRL, UART_CTRL_TXDIS | UART_CTRL_RXDIS); > + > + /* Configure baudrate */ > + if (in_freq && baudrate) { > + set_reg(UART_REG_BRGR, UART_BRGR_CD_CLKDIVISOR); > + set_reg(UART_REG_BDIVR, > + uart_min_clk_divisor(in_freq, baudrate)); > + } > + > + /* Software reset TX RX data path and enable TX RX */ > + set_reg(UART_REG_CTRL, UART_CTRL_TXRES | UART_CTRL_RXRES > + | UART_CTRL_TXEN | UART_CTRL_RXEN); > + > + /* > + * Set: > + * 1 stop bit, bits[07:06] = 0x00, > + * no parity set, bits[05:03] = 0x100, > + * 8 bits character length, bits[02:01] = 0x00, > + * sel_clk = uart_clk, bit[0] = 0x0 > + */ > + set_reg(UART_REG_MODE, UART_MODE_PAR_NONE); > + > + sbi_console_set_device(&cadence_console); > + > + return 0; > +} > diff --git a/lib/utils/serial/fdt_serial_cadence.c b/lib/utils/serial/fdt_serial_cadence.c > new file mode 100644 > index 0000000..946e533 > --- /dev/null > +++ b/lib/utils/serial/fdt_serial_cadence.c > @@ -0,0 +1,35 @@ > +/* > + * SPDX-License-Identifier: BSD-2-Clause > + * > + * Copyright (c) 2022 StarFive Technology Co., Ltd. > + * > + * Author: Jun Liang Tan <junliang.tan@linux.starfivetech.com> > + */ > + > +#include <sbi_utils/fdt/fdt_helper.h> > +#include <sbi_utils/serial/fdt_serial.h> > +#include <sbi_utils/serial/cadence-uart.h> > + > +static int serial_cadence_init(void *fdt, int nodeoff, > + const struct fdt_match *match) > +{ > + int rc; > + struct platform_uart_data uart = { 0 }; > + > + rc = fdt_parse_uart_node(fdt, nodeoff, &uart); > + if (rc) > + return rc; > + > + return cadence_uart_init(uart.addr, uart.freq, uart.baud); > +} > + > +static const struct fdt_match serial_cadence_match[] = { > + { .compatible = "cdns,uart-r1p12" }, > + { .compatible = "starfive,jh8100-uart" }, > + { }, > +}; > + > +struct fdt_serial fdt_serial_cadence = { > + .match_table = serial_cadence_match, > + .init = serial_cadence_init > +}; > diff --git a/lib/utils/serial/fdt_serial_uart8250.c b/lib/utils/serial/fdt_serial_uart8250.c > index 0b95f2d..7b5d6a4 100644 > --- a/lib/utils/serial/fdt_serial_uart8250.c > +++ b/lib/utils/serial/fdt_serial_uart8250.c > @@ -17,7 +17,7 @@ static int serial_uart8250_init(void *fdt, int nodeoff, > int rc; > struct platform_uart_data uart = { 0 }; > > - rc = fdt_parse_uart8250_node(fdt, nodeoff, &uart); > + rc = fdt_parse_uart_node(fdt, nodeoff, &uart); > if (rc) > return rc; > > diff --git a/lib/utils/serial/objects.mk b/lib/utils/serial/objects.mk > index fa9f5a3..efb1d9e 100644 > --- a/lib/utils/serial/objects.mk > +++ b/lib/utils/serial/objects.mk > @@ -10,6 +10,9 @@ > libsbiutils-objs-$(CONFIG_FDT_SERIAL) += serial/fdt_serial.o > libsbiutils-objs-$(CONFIG_FDT_SERIAL) += serial/fdt_serial_drivers.o > > +carray-fdt_serial_drivers-$(CONFIG_FDT_SERIAL_CADENCE) += fdt_serial_cadence > +libsbiutils-objs-$(CONFIG_FDT_SERIAL_CADENCE) += serial/fdt_serial_cadence.o > + > carray-fdt_serial_drivers-$(CONFIG_FDT_SERIAL_GAISLER) += fdt_serial_gaisler > libsbiutils-objs-$(CONFIG_FDT_SERIAL_GAISLER) += serial/fdt_serial_gaisler.o > > @@ -31,6 +34,7 @@ libsbiutils-objs-$(CONFIG_FDT_SERIAL_UART8250) += serial/fdt_serial_uart8250.o > carray-fdt_serial_drivers-$(CONFIG_FDT_SERIAL_XILINX_UARTLITE) += fdt_serial_xlnx_uartlite > libsbiutils-objs-$(CONFIG_FDT_SERIAL_XILINX_UARTLITE) += serial/fdt_serial_xlnx_uartlite.o > > +libsbiutils-objs-$(CONFIG_SERIAL_CADENCE) += serial/cadence-uart.o > libsbiutils-objs-$(CONFIG_SERIAL_GAISLER) += serial/gaisler-uart.o > libsbiutils-objs-$(CONFIG_SERIAL_SHAKTI) += serial/shakti-uart.o > libsbiutils-objs-$(CONFIG_SERIAL_SIFIVE) += serial/sifive-uart.o > diff --git a/platform/generic/configs/defconfig b/platform/generic/configs/defconfig > index 2a75394..e324173 100644 > --- a/platform/generic/configs/defconfig > +++ b/platform/generic/configs/defconfig > @@ -18,6 +18,7 @@ CONFIG_FDT_RESET_SIFIVE_TEST=y > CONFIG_FDT_RESET_SUNXI_WDT=y > CONFIG_FDT_RESET_THEAD=y > CONFIG_FDT_SERIAL=y > +CONFIG_FDT_SERIAL_CADENCE=y > CONFIG_FDT_SERIAL_GAISLER=y > CONFIG_FDT_SERIAL_HTIF=y > CONFIG_FDT_SERIAL_SHAKTI=y > -- > 2.37.1 > > > > -- > opensbi mailing list > opensbi@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/opensbi
On Mon, Aug 22, 2022 at 08:38:40AM +0530, Anup Patel wrote: > On Wed, Aug 17, 2022 at 9:11 PM Jun Liang Tan > <junliang.tan@linux.starfivetech.com> wrote: > > > > Add Cadence UART driver > > > > Signed-off-by: Jun Liang Tan <junliang.tan@linux.starfivetech.com> > > Signed-off-by: Wei Liang Lim <weiliang.lim@linux.starfivetech.com> > > Overall, this looks good except the divide-by-zero question raised by > other folks in uart_min_clk_divisor(). > > Reviewed-by: Anup Patel <anup@brainfault.org> > Hi Anup, I don't think there's an issue with the baud divisor calculation. The manual[1] I looked at for this UART states baud_rate = sel_clk / (CD * (BDIV + 1) which is the same as the sifive calculation except for the additional 'CD' term. However this driver sets CD == 1, which reduces it to the exact same as the sifive calculation. So the '- 1' in the calculation is correct, as just comes from the algebra applied to get BDIV. [*] https://docs.xilinx.com/v/u/en-US/ug585-Zynq-7000-TRM Thanks, drew
On Mon, Aug 22, 2022 at 2:08 PM Andrew Jones <ajones@ventanamicro.com> wrote: > > On Mon, Aug 22, 2022 at 08:38:40AM +0530, Anup Patel wrote: > > On Wed, Aug 17, 2022 at 9:11 PM Jun Liang Tan > > <junliang.tan@linux.starfivetech.com> wrote: > > > > > > Add Cadence UART driver > > > > > > Signed-off-by: Jun Liang Tan <junliang.tan@linux.starfivetech.com> > > > Signed-off-by: Wei Liang Lim <weiliang.lim@linux.starfivetech.com> > > > > Overall, this looks good except the divide-by-zero question raised by > > other folks in uart_min_clk_divisor(). > > > > Reviewed-by: Anup Patel <anup@brainfault.org> > > > > Hi Anup, > > I don't think there's an issue with the baud divisor calculation. > The manual[1] I looked at for this UART states > > baud_rate = sel_clk / (CD * (BDIV + 1) > > which is the same as the sifive calculation except for the additional > 'CD' term. > > However this driver sets CD == 1, which reduces it to the exact same > as the sifive calculation. > > So the '- 1' in the calculation is correct, as just comes from the > algebra applied to get BDIV. > > [*] https://docs.xilinx.com/v/u/en-US/ug585-Zynq-7000-TRM Thanks for the explanation Drew. Applied this patch to the riscv/opensbi repo. Regards, Anup
diff --git a/include/sbi_utils/fdt/fdt_helper.h b/include/sbi_utils/fdt/fdt_helper.h index c60af35..bcd4996 100644 --- a/include/sbi_utils/fdt/fdt_helper.h +++ b/include/sbi_utils/fdt/fdt_helper.h @@ -65,8 +65,8 @@ int fdt_parse_shakti_uart_node(void *fdt, int nodeoffset, int fdt_parse_sifive_uart_node(void *fdt, int nodeoffset, struct platform_uart_data *uart); -int fdt_parse_uart8250_node(void *fdt, int nodeoffset, - struct platform_uart_data *uart); +int fdt_parse_uart_node(void *fdt, int nodeoffset, + struct platform_uart_data *uart); int fdt_parse_uart8250(void *fdt, struct platform_uart_data *uart, const char *compatible); diff --git a/include/sbi_utils/serial/cadence-uart.h b/include/sbi_utils/serial/cadence-uart.h new file mode 100644 index 0000000..e75fb95 --- /dev/null +++ b/include/sbi_utils/serial/cadence-uart.h @@ -0,0 +1,16 @@ +/* + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2022 StarFive Technology Co., Ltd. + * + * Author: Jun Liang Tan <junliang.tan@linux.starfivetech.com> + */ + +#ifndef __SERIAL_CADENCE_UART_H__ +#define __SERIAL_CADENCE_UART_H__ + +#include <sbi/sbi_types.h> + +int cadence_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 c6abf80..6a75d6f 100644 --- a/lib/utils/fdt/fdt_helper.c +++ b/lib/utils/fdt/fdt_helper.c @@ -401,8 +401,8 @@ int fdt_parse_sifive_uart_node(void *fdt, int nodeoffset, return 0; } -int fdt_parse_uart8250_node(void *fdt, int nodeoffset, - struct platform_uart_data *uart) +int fdt_parse_uart_node(void *fdt, int nodeoffset, + struct platform_uart_data *uart) { int len, rc; const fdt32_t *val; @@ -447,7 +447,7 @@ int fdt_parse_uart8250(void *fdt, struct platform_uart_data *uart, if (nodeoffset < 0) return nodeoffset; - return fdt_parse_uart8250_node(fdt, nodeoffset, uart); + return fdt_parse_uart_node(fdt, nodeoffset, uart); } int fdt_parse_xlnx_uartlite_node(void *fdt, int nodeoffset, diff --git a/lib/utils/serial/Kconfig b/lib/utils/serial/Kconfig index 152060d..6e425f2 100644 --- a/lib/utils/serial/Kconfig +++ b/lib/utils/serial/Kconfig @@ -9,6 +9,11 @@ config FDT_SERIAL if FDT_SERIAL +config FDT_SERIAL_CADENCE + bool "Cadence UART FDT driver" + select SERIAL_CADENCE + default n + config FDT_SERIAL_GAISLER bool "Gaisler UART FDT driver" select SERIAL_GAISLER @@ -46,6 +51,10 @@ config FDT_SERIAL_XILINX_UARTLITE endif +config SERIAL_CADENCE + bool "Cadence UART support" + default n + config SERIAL_GAISLER bool "Gaisler UART support" default n diff --git a/lib/utils/serial/cadence-uart.c b/lib/utils/serial/cadence-uart.c new file mode 100644 index 0000000..8a2b6ba --- /dev/null +++ b/lib/utils/serial/cadence-uart.c @@ -0,0 +1,128 @@ +/* + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2022 StarFive Technology Co., Ltd. + * + * Author: Jun Liang Tan <junliang.tan@linux.starfivetech.com> + */ + +#include <sbi/riscv_io.h> +#include <sbi/sbi_console.h> +#include <sbi_utils/serial/cadence-uart.h> + +/* clang-format off */ + +#define UART_REG_CTRL 0x00 +#define UART_REG_MODE 0x04 +#define UART_REG_IDR 0x0C +#define UART_REG_BRGR 0x18 +#define UART_REG_CSR 0x2C +#define UART_REG_RFIFO_TFIFO 0x30 +#define UART_REG_BDIVR 0x34 + +#define UART_CTRL_RXRES 0x00000001 +#define UART_CTRL_TXRES 0x00000002 +#define UART_CTRL_RXEN 0x00000004 +#define UART_CTRL_RXDIS 0x00000008 +#define UART_CTRL_TXEN 0x00000010 +#define UART_CTRL_TXDIS 0x00000020 + +#define UART_MODE_PAR_NONE 0x00000020 /* No parity set */ + +#define UART_BRGR_CD_CLKDIVISOR 0x00000001 /* baud_sample = sel_clk */ + +#define UART_CSR_REMPTY 0x00000002 +#define UART_CSR_TFUL 0x00000010 + +/* clang-format on */ + +static volatile void *uart_base; +static u32 uart_in_freq; +static u32 uart_baudrate; + +/* + * Find minimum divisor divides in_freq to max_target_hz; + * Based on SiFive UART driver (sifive-uart.c) + */ +static inline unsigned int uart_min_clk_divisor(uint64_t in_freq, + uint64_t max_target_hz) +{ + uint64_t quotient = (in_freq + max_target_hz - 1) / (max_target_hz); + + /* Avoid underflow */ + if (quotient == 0) + return 0; + else + return quotient - 1; +} + +static u32 get_reg(u32 offset) +{ + return readl(uart_base + offset); +} + +static void set_reg(u32 offset, u32 val) +{ + writel(val, uart_base + offset); +} + +static void cadence_uart_putc(char ch) +{ + while (get_reg(UART_REG_CSR) & UART_CSR_TFUL) + ; + + set_reg(UART_REG_RFIFO_TFIFO, ch); +} + +static int cadence_uart_getc(void) +{ + u32 ret = get_reg(UART_REG_CSR); + + if (!(ret & UART_CSR_REMPTY)) + return get_reg(UART_REG_RFIFO_TFIFO); + + return -1; +} + +static struct sbi_console_device cadence_console = { + .name = "cadence_uart", + .console_putc = cadence_uart_putc, + .console_getc = cadence_uart_getc +}; + +int cadence_uart_init(unsigned long base, u32 in_freq, u32 baudrate) +{ + uart_base = (volatile void *)base; + uart_in_freq = in_freq; + uart_baudrate = baudrate; + + /* Disable interrupts */ + set_reg(UART_REG_IDR, 0xFFFFFFFF); + + /* Disable TX RX */ + set_reg(UART_REG_CTRL, UART_CTRL_TXDIS | UART_CTRL_RXDIS); + + /* Configure baudrate */ + if (in_freq && baudrate) { + set_reg(UART_REG_BRGR, UART_BRGR_CD_CLKDIVISOR); + set_reg(UART_REG_BDIVR, + uart_min_clk_divisor(in_freq, baudrate)); + } + + /* Software reset TX RX data path and enable TX RX */ + set_reg(UART_REG_CTRL, UART_CTRL_TXRES | UART_CTRL_RXRES + | UART_CTRL_TXEN | UART_CTRL_RXEN); + + /* + * Set: + * 1 stop bit, bits[07:06] = 0x00, + * no parity set, bits[05:03] = 0x100, + * 8 bits character length, bits[02:01] = 0x00, + * sel_clk = uart_clk, bit[0] = 0x0 + */ + set_reg(UART_REG_MODE, UART_MODE_PAR_NONE); + + sbi_console_set_device(&cadence_console); + + return 0; +} diff --git a/lib/utils/serial/fdt_serial_cadence.c b/lib/utils/serial/fdt_serial_cadence.c new file mode 100644 index 0000000..946e533 --- /dev/null +++ b/lib/utils/serial/fdt_serial_cadence.c @@ -0,0 +1,35 @@ +/* + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2022 StarFive Technology Co., Ltd. + * + * Author: Jun Liang Tan <junliang.tan@linux.starfivetech.com> + */ + +#include <sbi_utils/fdt/fdt_helper.h> +#include <sbi_utils/serial/fdt_serial.h> +#include <sbi_utils/serial/cadence-uart.h> + +static int serial_cadence_init(void *fdt, int nodeoff, + const struct fdt_match *match) +{ + int rc; + struct platform_uart_data uart = { 0 }; + + rc = fdt_parse_uart_node(fdt, nodeoff, &uart); + if (rc) + return rc; + + return cadence_uart_init(uart.addr, uart.freq, uart.baud); +} + +static const struct fdt_match serial_cadence_match[] = { + { .compatible = "cdns,uart-r1p12" }, + { .compatible = "starfive,jh8100-uart" }, + { }, +}; + +struct fdt_serial fdt_serial_cadence = { + .match_table = serial_cadence_match, + .init = serial_cadence_init +}; diff --git a/lib/utils/serial/fdt_serial_uart8250.c b/lib/utils/serial/fdt_serial_uart8250.c index 0b95f2d..7b5d6a4 100644 --- a/lib/utils/serial/fdt_serial_uart8250.c +++ b/lib/utils/serial/fdt_serial_uart8250.c @@ -17,7 +17,7 @@ static int serial_uart8250_init(void *fdt, int nodeoff, int rc; struct platform_uart_data uart = { 0 }; - rc = fdt_parse_uart8250_node(fdt, nodeoff, &uart); + rc = fdt_parse_uart_node(fdt, nodeoff, &uart); if (rc) return rc; diff --git a/lib/utils/serial/objects.mk b/lib/utils/serial/objects.mk index fa9f5a3..efb1d9e 100644 --- a/lib/utils/serial/objects.mk +++ b/lib/utils/serial/objects.mk @@ -10,6 +10,9 @@ libsbiutils-objs-$(CONFIG_FDT_SERIAL) += serial/fdt_serial.o libsbiutils-objs-$(CONFIG_FDT_SERIAL) += serial/fdt_serial_drivers.o +carray-fdt_serial_drivers-$(CONFIG_FDT_SERIAL_CADENCE) += fdt_serial_cadence +libsbiutils-objs-$(CONFIG_FDT_SERIAL_CADENCE) += serial/fdt_serial_cadence.o + carray-fdt_serial_drivers-$(CONFIG_FDT_SERIAL_GAISLER) += fdt_serial_gaisler libsbiutils-objs-$(CONFIG_FDT_SERIAL_GAISLER) += serial/fdt_serial_gaisler.o @@ -31,6 +34,7 @@ libsbiutils-objs-$(CONFIG_FDT_SERIAL_UART8250) += serial/fdt_serial_uart8250.o carray-fdt_serial_drivers-$(CONFIG_FDT_SERIAL_XILINX_UARTLITE) += fdt_serial_xlnx_uartlite libsbiutils-objs-$(CONFIG_FDT_SERIAL_XILINX_UARTLITE) += serial/fdt_serial_xlnx_uartlite.o +libsbiutils-objs-$(CONFIG_SERIAL_CADENCE) += serial/cadence-uart.o libsbiutils-objs-$(CONFIG_SERIAL_GAISLER) += serial/gaisler-uart.o libsbiutils-objs-$(CONFIG_SERIAL_SHAKTI) += serial/shakti-uart.o libsbiutils-objs-$(CONFIG_SERIAL_SIFIVE) += serial/sifive-uart.o diff --git a/platform/generic/configs/defconfig b/platform/generic/configs/defconfig index 2a75394..e324173 100644 --- a/platform/generic/configs/defconfig +++ b/platform/generic/configs/defconfig @@ -18,6 +18,7 @@ CONFIG_FDT_RESET_SIFIVE_TEST=y CONFIG_FDT_RESET_SUNXI_WDT=y CONFIG_FDT_RESET_THEAD=y CONFIG_FDT_SERIAL=y +CONFIG_FDT_SERIAL_CADENCE=y CONFIG_FDT_SERIAL_GAISLER=y CONFIG_FDT_SERIAL_HTIF=y CONFIG_FDT_SERIAL_SHAKTI=y