/* * Copyright (C) 2012 Michal Simek <monstr@monstr.eu> * Copyright (C) 2011-2012 Xilinx, Inc. All rights reserved. * * SPDX-License-Identifier: GPL-2.0+ */ #include <common.h> #include <fdtdec.h> #include <watchdog.h> #include <asm/io.h> #include <linux/compiler.h> #include <serial.h> #include <asm/arch/clk.h> #include <asm/arch/hardware.h> DECLARE_GLOBAL_DATA_PTR; #define ZYNQ_UART_SR_TXFULL 0x00000010 /* TX FIFO full */ #define ZYNQ_UART_SR_RXEMPTY 0x00000002 /* RX FIFO empty */ #define ZYNQ_UART_CR_TX_EN 0x00000010 /* TX enabled */ #define ZYNQ_UART_CR_RX_EN 0x00000004 /* RX enabled */ #define ZYNQ_UART_CR_TXRST 0x00000002 /* TX logic reset */ #define ZYNQ_UART_CR_RXRST 0x00000001 /* RX logic reset */ #define ZYNQ_UART_MR_PARITY_NONE 0x00000020 /* No parity mode */ struct uart_zynq { u32 control; /* 0x0 - Control Register [8:0] */ u32 mode; /* 0x4 - Mode Register [10:0] */ u32 reserved1[4]; u32 baud_rate_gen; /* 0x18 - Baud Rate Generator [15:0] */ u32 reserved2[4]; u32 channel_sts; /* 0x2c - Channel Status [11:0] */ u32 tx_rx_fifo; /* 0x30 - FIFO [15:0] or [7:0] */ u32 baud_rate_divider; /* 0x34 - Baud Rate Divider [7:0] */ }; static struct uart_zynq *uart_zynq_ports[2] = { [0] = (struct uart_zynq *)ZYNQ_SERIAL_BASEADDR0, [1] = (struct uart_zynq *)ZYNQ_SERIAL_BASEADDR1, }; /* Set up the baud rate in gd struct */ static void uart_zynq_serial_setbrg(const int port) { /* Calculation results. */ unsigned int calc_bauderror, bdiv, bgen; unsigned long calc_baud = 0; unsigned long baud; unsigned long clock = get_uart_clk(port); struct uart_zynq *regs = uart_zynq_ports[port]; /* Covering case where input clock is so slow */ if (clock < 1000000 && gd->baudrate > 4800) gd->baudrate = 4800; baud = gd->baudrate; /* master clock * Baud rate = ------------------ * bgen * (bdiv + 1) * * Find acceptable values for baud generation. */ for (bdiv = 4; bdiv < 255; bdiv++) { bgen = clock / (baud * (bdiv + 1)); if (bgen < 2 || bgen > 65535) continue; calc_baud = clock / (bgen * (bdiv + 1)); /* * Use first calculated baudrate with * an acceptable (<3%) error */ if (baud > calc_baud) calc_bauderror = baud - calc_baud; else calc_bauderror = calc_baud - baud; if (((calc_bauderror * 100) / baud) < 3) break; } writel(bdiv, ®s->baud_rate_divider); writel(bgen, ®s->baud_rate_gen); } /* Initialize the UART, with...some settings. */ static int uart_zynq_serial_init(const int port) { struct uart_zynq *regs = uart_zynq_ports[port]; if (!regs) return -1; /* RX/TX enabled & reset */ writel(ZYNQ_UART_CR_TX_EN | ZYNQ_UART_CR_RX_EN | ZYNQ_UART_CR_TXRST | \ ZYNQ_UART_CR_RXRST, ®s->control); writel(ZYNQ_UART_MR_PARITY_NONE, ®s->mode); /* 8 bit, no parity */ uart_zynq_serial_setbrg(port); return 0; } static void uart_zynq_serial_putc(const char c, const int port) { struct uart_zynq *regs = uart_zynq_ports[port]; while ((readl(®s->channel_sts) & ZYNQ_UART_SR_TXFULL) != 0) WATCHDOG_RESET(); if (c == '\n') { writel('\r', ®s->tx_rx_fifo); while ((readl(®s->channel_sts) & ZYNQ_UART_SR_TXFULL) != 0) WATCHDOG_RESET(); } writel(c, ®s->tx_rx_fifo); } static void uart_zynq_serial_puts(const char *s, const int port) { while (*s) uart_zynq_serial_putc(*s++, port); } static int uart_zynq_serial_tstc(const int port) { struct uart_zynq *regs = uart_zynq_ports[port]; return (readl(®s->channel_sts) & ZYNQ_UART_SR_RXEMPTY) == 0; } static int uart_zynq_serial_getc(const int port) { struct uart_zynq *regs = uart_zynq_ports[port]; while (!uart_zynq_serial_tstc(port)) WATCHDOG_RESET(); return readl(®s->tx_rx_fifo); } /* Multi serial device functions */ #define DECLARE_PSSERIAL_FUNCTIONS(port) \ static int uart_zynq##port##_init(void) \ { return uart_zynq_serial_init(port); } \ static void uart_zynq##port##_setbrg(void) \ { return uart_zynq_serial_setbrg(port); } \ static int uart_zynq##port##_getc(void) \ { return uart_zynq_serial_getc(port); } \ static int uart_zynq##port##_tstc(void) \ { return uart_zynq_serial_tstc(port); } \ static void uart_zynq##port##_putc(const char c) \ { uart_zynq_serial_putc(c, port); } \ static void uart_zynq##port##_puts(const char *s) \ { uart_zynq_serial_puts(s, port); } /* Serial device descriptor */ #define INIT_PSSERIAL_STRUCTURE(port, __name) { \ .name = __name, \ .start = uart_zynq##port##_init, \ .stop = NULL, \ .setbrg = uart_zynq##port##_setbrg, \ .getc = uart_zynq##port##_getc, \ .tstc = uart_zynq##port##_tstc, \ .putc = uart_zynq##port##_putc, \ .puts = uart_zynq##port##_puts, \ } DECLARE_PSSERIAL_FUNCTIONS(0); static struct serial_device uart_zynq_serial0_device = INIT_PSSERIAL_STRUCTURE(0, "ttyPS0"); DECLARE_PSSERIAL_FUNCTIONS(1); static struct serial_device uart_zynq_serial1_device = INIT_PSSERIAL_STRUCTURE(1, "ttyPS1"); #if CONFIG_IS_ENABLED(OF_CONTROL) __weak struct serial_device *default_serial_console(void) { const void *blob = gd->fdt_blob; int node; unsigned int base_addr; node = fdt_path_offset(blob, "serial0"); if (node < 0) return NULL; base_addr = fdtdec_get_addr(blob, node, "reg"); if (base_addr == FDT_ADDR_T_NONE) return NULL; if (base_addr == ZYNQ_SERIAL_BASEADDR0) return &uart_zynq_serial0_device; if (base_addr == ZYNQ_SERIAL_BASEADDR1) return &uart_zynq_serial1_device; return NULL; } #else __weak struct serial_device *default_serial_console(void) { #if defined(CONFIG_ZYNQ_SERIAL_UART0) if (uart_zynq_ports[0]) return &uart_zynq_serial0_device; #endif #if defined(CONFIG_ZYNQ_SERIAL_UART1) if (uart_zynq_ports[1]) return &uart_zynq_serial1_device; #endif return NULL; } #endif void zynq_serial_initialize(void) { serial_register(&uart_zynq_serial0_device); serial_register(&uart_zynq_serial1_device); }