From: Jun Liang Tan Date: Fri, 15 Jul 2022 10:40:54 +0800 Subject: [PATCH v2] lib: utils: serial: Add Cadence UART driver Message-ID: <20220715024054.7326-1-junliang.tan@linux.starfivetech.com> List-Id: To: opensbi@lists.infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Add Cadence UART driver Signed-off-by: Jun Liang Tan Signed-off-by: Wei Liang Lim --- 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/cadence-uart.c | 125 ++++++++++++++++++++++++ lib/utils/serial/fdt_serial_cadence.c | 35 +++++++ lib/utils/serial/fdt_serial_uart8250.c | 2 +- lib/utils/serial/objects.mk | 4 + 7 files changed, 186 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 + */ + +#ifndef __SERIAL_CADENCE_UART_H__ +#define __SERIAL_CADENCE_UART_H__ + +#include + +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 2bdb1ef..1e136fe 100644 --- a/lib/utils/fdt/fdt_helper.c +++ b/lib/utils/fdt/fdt_helper.c @@ -427,8 +427,8 @@ 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; @@ -492,7 +492,7 @@ 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/cadence-uart.c b/lib/utils/serial/cadence-uart.c new file mode 100644 index 0000000..ffa79f8 --- /dev/null +++ b/lib/utils/serial/cadence-uart.c @@ -0,0 +1,125 @@ +/* + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2022 StarFive Technology Co., Ltd. + * + * Author: Jun Liang Tan + */ + +#include +#include +#include + +/* clang-format off */ + +#define UART_REG_OFFSET_CTRL 0x00 /* Control register */ +#define UART_REG_OFFSET_MODE 0x04 /* Mode register */ +#define UART_REG_OFFSET_CH_STS 0x2C /* Channel status register */ +#define UART_REG_OFFSET_RX_TX_FIFO 0x30 /* RX and TX FIFO register */ +#define UART_REG_OFFSET_INT_DIS 0x0C /* Interrupt disable register */ +#define UART_REG_OFFSET_BRG 0x18 /* Baud rate generator register */ +#define UART_REG_OFFSET_BRD 0x34 /* Baud rate divider register */ + +/* Control register, 0x00 */ +#define UART_CR_TX_DIS 0x00000020 /* TX disabled, bit 5 */ +#define UART_CR_TX_EN 0x00000010 /* TX enabled, bit 4 */ +#define UART_CR_RX_DIS 0x00000008 /* RX disabled, bit 3 */ +#define UART_CR_RX_EN 0x00000004 /* RX enabled, bit 2*/ +#define UART_CR_TXRST 0x00000002 /* TX logic reset, bit 1 */ +#define UART_CR_RXRST 0x00000001 /* RX logic reset, bit 0 */ + +/* Channel status register, 0x2C */ +#define UART_CHSR_TXFULL 0x00000010 /* TX FIFO full, bit 4 */ +#define UART_CHSR_RXEMPTY 0x00000002 /* RX FIFO empty, bit 1 */ + +/* Mode register, 0x04 */ +#define UART_MR_PARITY_NONE 0x00000020 /* No parity set */ + +/* Baud rate generator register, 0x18 */ +#define UART_BRG_CLK_DIVISOR 0x00000001 /* baud_sample = sel_clk */ + +/* 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_OFFSET_CH_STS) & UART_CHSR_TXFULL) + ; + + set_reg(UART_REG_OFFSET_RX_TX_FIFO, ch); +} + +static int cadence_uart_getc(void) +{ + u32 ret = get_reg(UART_REG_OFFSET_CH_STS); + + if (!(ret & UART_CHSR_RXEMPTY)) + return get_reg(UART_REG_OFFSET_RX_TX_FIFO); + 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_OFFSET_INT_DIS, 0xFFFFFFFF); + /* Disable TX RX */ + set_reg(UART_REG_OFFSET_CTRL, UART_CR_TX_DIS | UART_CR_RX_DIS); + /* Configure baudrate */ + if (in_freq) { + set_reg(UART_REG_OFFSET_BRG, UART_BRG_CLK_DIVISOR); + set_reg(UART_REG_OFFSET_BRD, + uart_min_clk_divisor(in_freq, baudrate)); + } + /* Software reset TX RX data path and enable TX RX */ + set_reg(UART_REG_OFFSET_CTRL, UART_CR_TXRST | UART_CR_RXRST + | UART_CR_TX_EN | UART_CR_RX_EN); + /* 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_OFFSET_MODE, UART_MR_PARITY_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..2357520 --- /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 + */ + +#include +#include +#include + +static int serial_cadence_init(void *fdt, int nodeoff, + const struct fdt_match *match) +{ + int rc; + struct platform_uart_data uart; + + 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 544b741..0287f51 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; - 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 d26a74e..76d6f94 100644 --- a/lib/utils/serial/objects.mk +++ b/lib/utils/serial/objects.mk @@ -10,6 +10,9 @@ libsbiutils-objs-y += serial/fdt_serial.o libsbiutils-objs-y += serial/fdt_serial_drivers.o +carray-fdt_serial_drivers-y += fdt_serial_cadence +libsbiutils-objs-y += serial/fdt_serial_cadence.o + carray-fdt_serial_drivers-y += fdt_serial_gaisler libsbiutils-objs-y += serial/fdt_serial_gaisler.o @@ -31,6 +34,7 @@ libsbiutils-objs-y += serial/fdt_serial_uart8250.o carray-fdt_serial_drivers-y += fdt_serial_xlnx_uartlite libsbiutils-objs-y += serial/fdt_serial_xlnx_uartlite.o +libsbiutils-objs-y += serial/cadence-uart.o libsbiutils-objs-y += serial/gaisler-uart.o libsbiutils-objs-y += serial/shakti-uart.o libsbiutils-objs-y += serial/sifive-uart.o -- 2.37.0