1 /* 2 * COM1 NS16550 support 3 * originally from linux source (arch/powerpc/boot/ns16550.c) 4 * modified to use CONFIG_SYS_ISA_MEM and new defines 5 */ 6 7 #include <config.h> 8 #include <ns16550.h> 9 #include <watchdog.h> 10 #include <linux/types.h> 11 #include <asm/io.h> 12 13 #define UART_LCRVAL UART_LCR_8N1 /* 8 data, 1 stop, no parity */ 14 #define UART_MCRVAL (UART_MCR_DTR | \ 15 UART_MCR_RTS) /* RTS/DTR */ 16 #define UART_FCRVAL (UART_FCR_FIFO_EN | \ 17 UART_FCR_RXSR | \ 18 UART_FCR_TXSR) /* Clear & enable FIFOs */ 19 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED 20 #define serial_out(x, y) outb(x, (ulong)y) 21 #define serial_in(y) inb((ulong)y) 22 #elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0) 23 #define serial_out(x, y) out_be32(y, x) 24 #define serial_in(y) in_be32(y) 25 #elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0) 26 #define serial_out(x, y) out_le32(y, x) 27 #define serial_in(y) in_le32(y) 28 #else 29 #define serial_out(x, y) writeb(x, y) 30 #define serial_in(y) readb(y) 31 #endif 32 33 #ifndef CONFIG_SYS_NS16550_IER 34 #define CONFIG_SYS_NS16550_IER 0x00 35 #endif /* CONFIG_SYS_NS16550_IER */ 36 37 void NS16550_init(NS16550_t com_port, int baud_divisor) 38 { 39 #if (defined(CONFIG_SPL_BUILD) && defined(CONFIG_OMAP34XX)) 40 /* 41 * On some OMAP3 devices when UART3 is configured for boot mode before 42 * SPL starts only THRE bit is set. We have to empty the transmitter 43 * before initialization starts. 44 */ 45 if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT | UART_LSR_THRE)) 46 == UART_LSR_THRE) { 47 serial_out(UART_LCR_DLAB, &com_port->lcr); 48 serial_out(baud_divisor & 0xff, &com_port->dll); 49 serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm); 50 serial_out(UART_LCRVAL, &com_port->lcr); 51 serial_out(0, &com_port->mdr1); 52 } 53 #endif 54 55 while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT)) 56 ; 57 58 serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier); 59 #if (defined(CONFIG_OMAP) && !defined(CONFIG_OMAP3_ZOOM2)) || \ 60 defined(CONFIG_AM33XX) || defined(CONFIG_TI81XX) || \ 61 defined(CONFIG_AM43XX) 62 serial_out(0x7, &com_port->mdr1); /* mode select reset TL16C750*/ 63 #endif 64 serial_out(UART_LCR_BKSE | UART_LCRVAL, &com_port->lcr); 65 serial_out(0, &com_port->dll); 66 serial_out(0, &com_port->dlm); 67 serial_out(UART_LCRVAL, &com_port->lcr); 68 serial_out(UART_MCRVAL, &com_port->mcr); 69 serial_out(UART_FCRVAL, &com_port->fcr); 70 serial_out(UART_LCR_BKSE | UART_LCRVAL, &com_port->lcr); 71 serial_out(baud_divisor & 0xff, &com_port->dll); 72 serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm); 73 serial_out(UART_LCRVAL, &com_port->lcr); 74 #if (defined(CONFIG_OMAP) && !defined(CONFIG_OMAP3_ZOOM2)) || \ 75 defined(CONFIG_AM33XX) || defined(CONFIG_SOC_DA8XX) || \ 76 defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX) 77 78 /* /16 is proper to hit 115200 with 48MHz */ 79 serial_out(0, &com_port->mdr1); 80 #endif /* CONFIG_OMAP */ 81 } 82 83 #ifndef CONFIG_NS16550_MIN_FUNCTIONS 84 void NS16550_reinit(NS16550_t com_port, int baud_divisor) 85 { 86 serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier); 87 serial_out(UART_LCR_BKSE | UART_LCRVAL, &com_port->lcr); 88 serial_out(0, &com_port->dll); 89 serial_out(0, &com_port->dlm); 90 serial_out(UART_LCRVAL, &com_port->lcr); 91 serial_out(UART_MCRVAL, &com_port->mcr); 92 serial_out(UART_FCRVAL, &com_port->fcr); 93 serial_out(UART_LCR_BKSE, &com_port->lcr); 94 serial_out(baud_divisor & 0xff, &com_port->dll); 95 serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm); 96 serial_out(UART_LCRVAL, &com_port->lcr); 97 } 98 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */ 99 100 void NS16550_putc(NS16550_t com_port, char c) 101 { 102 while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0) 103 ; 104 serial_out(c, &com_port->thr); 105 106 /* 107 * Call watchdog_reset() upon newline. This is done here in putc 108 * since the environment code uses a single puts() to print the complete 109 * environment upon "printenv". So we can't put this watchdog call 110 * in puts(). 111 */ 112 if (c == '\n') 113 WATCHDOG_RESET(); 114 } 115 116 #ifndef CONFIG_NS16550_MIN_FUNCTIONS 117 char NS16550_getc(NS16550_t com_port) 118 { 119 while ((serial_in(&com_port->lsr) & UART_LSR_DR) == 0) { 120 #if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_USB_TTY) 121 extern void usbtty_poll(void); 122 usbtty_poll(); 123 #endif 124 WATCHDOG_RESET(); 125 } 126 return serial_in(&com_port->rbr); 127 } 128 129 int NS16550_tstc(NS16550_t com_port) 130 { 131 return (serial_in(&com_port->lsr) & UART_LSR_DR) != 0; 132 } 133 134 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */ 135