diff options
Diffstat (limited to 'drivers/serial/serial_bfin.c')
| -rw-r--r-- | drivers/serial/serial_bfin.c | 411 |
1 files changed, 411 insertions, 0 deletions
diff --git a/drivers/serial/serial_bfin.c b/drivers/serial/serial_bfin.c new file mode 100644 index 000000000..0443b8427 --- /dev/null +++ b/drivers/serial/serial_bfin.c @@ -0,0 +1,411 @@ +/* + * U-boot - serial.c Blackfin Serial Driver + * + * Copyright (c) 2005-2008 Analog Devices Inc. + * + * Copyright (c) 2003 Bas Vermeulen <bas@buyways.nl>, + * BuyWays B.V. (www.buyways.nl) + * + * Based heavily on: + * blkfinserial.c: Serial driver for BlackFin DSP internal USRTs. + * Copyright(c) 2003 Metrowerks <mwaddel@metrowerks.com> + * Copyright(c) 2001 Tony Z. Kou <tonyko@arcturusnetworks.com> + * Copyright(c) 2001-2002 Arcturus Networks Inc. <www.arcturusnetworks.com> + * + * Based on code from 68328 version serial driver imlpementation which was: + * Copyright (C) 1995 David S. Miller <davem@caip.rutgers.edu> + * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com> + * Copyright (C) 1998, 1999 D. Jeff Dionne <jeff@uclinux.org> + * Copyright (C) 1999 Vladimir Gurevich <vgurevic@cisco.com> + * + * (C) Copyright 2000-2004 + * Wolfgang Denk, DENX Software Engineering, wd@denx.de. + * + * Licensed under the GPL-2 or later. + */ + +/* Anomaly notes: + * 05000086 - we don't support autobaud + * 05000099 - we only use DR bit, so losing others is not a problem + * 05000100 - we don't use the UART_IIR register + * 05000215 - we poll the uart (no dma/interrupts) + * 05000225 - no workaround possible, but this shouldnt cause errors ... + * 05000230 - we tweak the baud rate calculation slightly + * 05000231 - we always use 1 stop bit + * 05000309 - we always enable the uart before we modify it in anyway + * 05000350 - we always enable the uart regardless of boot mode + * 05000363 - we don't support break signals, so don't generate one + */ + +#include <common.h> +#include <post.h> +#include <watchdog.h> +#include <serial.h> +#include <linux/compiler.h> +#include <asm/blackfin.h> +#include <asm/serial.h> + +DECLARE_GLOBAL_DATA_PTR; + +#ifdef CONFIG_UART_CONSOLE + +#ifdef CONFIG_DEBUG_SERIAL +static uart_lsr_t cached_lsr[256]; +static uart_lsr_t cached_rbr[256]; +static size_t cache_count; + +/* The LSR is read-to-clear on some parts, so we have to make sure status + * bits aren't inadvertently lost when doing various tests. This also + * works around anomaly 05000099 at the same time by keeping a cumulative + * tally of all the status bits. + */ +static uart_lsr_t uart_lsr_save; +static uart_lsr_t uart_lsr_read(uint32_t uart_base) +{ + uart_lsr_t lsr = _lsr_read(pUART); + uart_lsr_save |= (lsr & (OE|PE|FE|BI)); + return lsr | uart_lsr_save; +} +/* Just do the clear for everyone since it can't hurt. */ +static void uart_lsr_clear(uint32_t uart_base) +{ + uart_lsr_save = 0; + _lsr_write(pUART, -1); +} +#else +/* When debugging is disabled, we only care about the DR bit, so if other + * bits get set/cleared, we don't really care since we don't read them + * anyways (and thus anomaly 05000099 is irrelevant). + */ +static inline uart_lsr_t uart_lsr_read(uint32_t uart_base) +{ + return _lsr_read(pUART); +} +static void uart_lsr_clear(uint32_t uart_base) +{ + _lsr_write(pUART, -1); +} +#endif + +static void uart_putc(uint32_t uart_base, const char c) +{ + /* send a \r for compatibility */ + if (c == '\n') + serial_putc('\r'); + + WATCHDOG_RESET(); + + /* wait for the hardware fifo to clear up */ + while (!(uart_lsr_read(uart_base) & THRE)) + continue; + + /* queue the character for transmission */ + bfin_write(&pUART->thr, c); + SSYNC(); + + WATCHDOG_RESET(); +} + +static int uart_tstc(uint32_t uart_base) +{ + WATCHDOG_RESET(); + return (uart_lsr_read(uart_base) & DR) ? 1 : 0; +} + +static int uart_getc(uint32_t uart_base) +{ + uint16_t uart_rbr_val; + + /* wait for data ! */ + while (!uart_tstc(uart_base)) + continue; + + /* grab the new byte */ + uart_rbr_val = bfin_read(&pUART->rbr); + +#ifdef CONFIG_DEBUG_SERIAL + /* grab & clear the LSR */ + uart_lsr_t uart_lsr_val = uart_lsr_read(uart_base); + + cached_lsr[cache_count] = uart_lsr_val; + cached_rbr[cache_count] = uart_rbr_val; + cache_count = (cache_count + 1) % ARRAY_SIZE(cached_lsr); + + if (uart_lsr_val & (OE|PE|FE|BI)) { + printf("\n[SERIAL ERROR]\n"); + do { + --cache_count; + printf("\t%3zu: RBR=0x%02x LSR=0x%02x\n", cache_count, + cached_rbr[cache_count], cached_lsr[cache_count]); + } while (cache_count > 0); + return -1; + } +#endif + uart_lsr_clear(uart_base); + + return uart_rbr_val; +} + +#if CONFIG_POST & CONFIG_SYS_POST_UART +# define LOOP(x) x +#else +# define LOOP(x) +#endif + +#if BFIN_UART_HW_VER < 4 + +LOOP( +static void uart_loop(uint32_t uart_base, int state) +{ + u16 mcr; + + /* Drain the TX fifo first so bytes don't come back */ + while (!(uart_lsr_read(uart_base) & TEMT)) + continue; + + mcr = bfin_read(&pUART->mcr); + if (state) + mcr |= LOOP_ENA | MRTS; + else + mcr &= ~(LOOP_ENA | MRTS); + bfin_write(&pUART->mcr, mcr); +} +) + +#else + +LOOP( +static void uart_loop(uint32_t uart_base, int state) +{ + u32 control; + + /* Drain the TX fifo first so bytes don't come back */ + while (!(uart_lsr_read(uart_base) & TEMT)) + continue; + + control = bfin_read(&pUART->control); + if (state) + control |= LOOP_ENA | MRTS; + else + control &= ~(LOOP_ENA | MRTS); + bfin_write(&pUART->control, control); +} +) + +#endif + +static inline void __serial_set_baud(uint32_t uart_base, uint32_t baud) +{ +#ifdef CONFIG_DEBUG_EARLY_SERIAL + serial_early_set_baud(uart_base, baud); +#else + uint16_t divisor = (get_uart_clk() + (baud * 8)) / (baud * 16) + - ANOMALY_05000230; + + /* Program the divisor to get the baud rate we want */ + serial_set_divisor(uart_base, divisor); +#endif +} + +static void uart_puts(uint32_t uart_base, const char *s) +{ + while (*s) + uart_putc(uart_base, *s++); +} + +#define DECL_BFIN_UART(n) \ +static int uart##n##_init(void) \ +{ \ + const unsigned short pins[] = { _P_UART(n, RX), _P_UART(n, TX), 0, }; \ + peripheral_request_list(pins, "bfin-uart"); \ + uart_init(MMR_UART(n)); \ + __serial_set_baud(MMR_UART(n), gd->baudrate); \ + uart_lsr_clear(MMR_UART(n)); \ + return 0; \ +} \ +\ +static int uart##n##_uninit(void) \ +{ \ + return serial_early_uninit(MMR_UART(n)); \ +} \ +\ +static void uart##n##_setbrg(void) \ +{ \ + __serial_set_baud(MMR_UART(n), gd->baudrate); \ +} \ +\ +static int uart##n##_getc(void) \ +{ \ + return uart_getc(MMR_UART(n)); \ +} \ +\ +static int uart##n##_tstc(void) \ +{ \ + return uart_tstc(MMR_UART(n)); \ +} \ +\ +static void uart##n##_putc(const char c) \ +{ \ + uart_putc(MMR_UART(n), c); \ +} \ +\ +static void uart##n##_puts(const char *s) \ +{ \ + uart_puts(MMR_UART(n), s); \ +} \ +\ +LOOP( \ +static void uart##n##_loop(int state) \ +{ \ + uart_loop(MMR_UART(n), state); \ +} \ +) \ +\ +struct serial_device bfin_serial##n##_device = { \ + .name = "bfin_uart"#n, \ + .start = uart##n##_init, \ + .stop = uart##n##_uninit, \ + .setbrg = uart##n##_setbrg, \ + .getc = uart##n##_getc, \ + .tstc = uart##n##_tstc, \ + .putc = uart##n##_putc, \ + .puts = uart##n##_puts, \ + LOOP(.loop = uart##n##_loop) \ +}; + +#ifdef UART0_RBR +DECL_BFIN_UART(0) +#endif +#ifdef UART1_RBR +DECL_BFIN_UART(1) +#endif +#ifdef UART2_RBR +DECL_BFIN_UART(2) +#endif +#ifdef UART3_RBR +DECL_BFIN_UART(3) +#endif + +__weak struct serial_device *default_serial_console(void) +{ +#if CONFIG_UART_CONSOLE == 0 + return &bfin_serial0_device; +#elif CONFIG_UART_CONSOLE == 1 + return &bfin_serial1_device; +#elif CONFIG_UART_CONSOLE == 2 + return &bfin_serial2_device; +#elif CONFIG_UART_CONSOLE == 3 + return &bfin_serial3_device; +#endif +} + +void bfin_serial_initialize(void) +{ +#ifdef UART0_RBR + serial_register(&bfin_serial0_device); +#endif +#ifdef UART1_RBR + serial_register(&bfin_serial1_device); +#endif +#ifdef UART2_RBR + serial_register(&bfin_serial2_device); +#endif +#ifdef UART3_RBR + serial_register(&bfin_serial3_device); +#endif +} + +#ifdef CONFIG_DEBUG_EARLY_SERIAL +inline void uart_early_putc(uint32_t uart_base, const char c) +{ + /* send a \r for compatibility */ + if (c == '\n') + uart_early_putc(uart_base, '\r'); + + /* wait for the hardware fifo to clear up */ + while (!(_lsr_read(pUART) & THRE)) + continue; + + /* queue the character for transmission */ + bfin_write(&pUART->thr, c); + SSYNC(); +} + +void uart_early_puts(const char *s) +{ + while (*s) + uart_early_putc(UART_BASE, *s++); +} + +/* Symbol for our assembly to call. */ +void _serial_early_set_baud(uint32_t baud) +{ + serial_early_set_baud(UART_BASE, baud); +} + +/* Symbol for our assembly to call. */ +void _serial_early_init(void) +{ + serial_early_init(UART_BASE); +} +#endif + +#elif defined(CONFIG_UART_MEM) + +char serial_logbuf[CONFIG_UART_MEM]; +char *serial_logbuf_head = serial_logbuf; + +int serial_mem_init(void) +{ + serial_logbuf_head = serial_logbuf; + return 0; +} + +void serial_mem_setbrg(void) +{ +} + +int serial_mem_tstc(void) +{ + return 0; +} + +int serial_mem_getc(void) +{ + return 0; +} + +void serial_mem_putc(const char c) +{ + *serial_logbuf_head = c; + if (++serial_logbuf_head == serial_logbuf + CONFIG_UART_MEM) + serial_logbuf_head = serial_logbuf; +} + +void serial_mem_puts(const char *s) +{ + while (*s) + serial_putc(*s++); +} + +struct serial_device bfin_serial_mem_device = { + .name = "bfin_uart_mem", + .start = serial_mem_init, + .setbrg = serial_mem_setbrg, + .getc = serial_mem_getc, + .tstc = serial_mem_tstc, + .putc = serial_mem_putc, + .puts = serial_mem_puts, +}; + + +__weak struct serial_device *default_serial_console(void) +{ + return &bfin_serial_mem_device; +} + +void bfin_serial_initialize(void) +{ + serial_register(&bfin_serial_mem_device); +} +#endif /* CONFIG_UART_MEM */ |