xref: /optee_os/core/drivers/imx_uart.c (revision a50cb361d9e5735f197ccc87beb0d24af8315369)
1 /*
2  * Copyright (C) 2015 Freescale Semiconductor, Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright notice,
9  * this list of conditions and the following disclaimer.
10  *
11  * 2. Redistributions in binary form must reproduce the above copyright notice,
12  * this list of conditions and the following disclaimer in the documentation
13  * and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
19  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25  * POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <platform_config.h>
29 
30 #include <drivers/imx_uart.h>
31 #include <console.h>
32 #include <io.h>
33 #include <compiler.h>
34 
35 /* Register definitions */
36 #define URXD  0x0  /* Receiver Register */
37 #define UTXD  0x40 /* Transmitter Register */
38 #define UCR1  0x80 /* Control Register 1 */
39 #define UCR2  0x84 /* Control Register 2 */
40 #define UCR3  0x88 /* Control Register 3 */
41 #define UCR4  0x8c /* Control Register 4 */
42 #define UFCR  0x90 /* FIFO Control Register */
43 #define USR1  0x94 /* Status Register 1 */
44 #define USR2  0x98 /* Status Register 2 */
45 #define UESC  0x9c /* Escape Character Register */
46 #define UTIM  0xa0 /* Escape Timer Register */
47 #define UBIR  0xa4 /* BRM Incremental Register */
48 #define UBMR  0xa8 /* BRM Modulator Register */
49 #define UBRC  0xac /* Baud Rate Count Register */
50 #define UTS   0xb4 /* UART Test Register (mx31) */
51 
52 /* UART Control Register Bit Fields.*/
53 #define  URXD_CHARRDY    (1<<15)
54 #define  URXD_ERR        (1<<14)
55 #define  URXD_OVRRUN     (1<<13)
56 #define  URXD_FRMERR     (1<<12)
57 #define  URXD_BRK        (1<<11)
58 #define  URXD_PRERR      (1<<10)
59 #define  URXD_RX_DATA    (0xFF)
60 #define  UCR1_ADEN       (1<<15) /* Auto dectect interrupt */
61 #define  UCR1_ADBR       (1<<14) /* Auto detect baud rate */
62 #define  UCR1_TRDYEN     (1<<13) /* Transmitter ready interrupt enable */
63 #define  UCR1_IDEN       (1<<12) /* Idle condition interrupt */
64 #define  UCR1_RRDYEN     (1<<9)	 /* Recv ready interrupt enable */
65 #define  UCR1_RDMAEN     (1<<8)	 /* Recv ready DMA enable */
66 #define  UCR1_IREN       (1<<7)	 /* Infrared interface enable */
67 #define  UCR1_TXMPTYEN   (1<<6)	 /* Transimitter empty interrupt enable */
68 #define  UCR1_RTSDEN     (1<<5)	 /* RTS delta interrupt enable */
69 #define  UCR1_SNDBRK     (1<<4)	 /* Send break */
70 #define  UCR1_TDMAEN     (1<<3)	 /* Transmitter ready DMA enable */
71 #define  UCR1_UARTCLKEN  (1<<2)	 /* UART clock enabled */
72 #define  UCR1_DOZE       (1<<1)	 /* Doze */
73 #define  UCR1_UARTEN     (1<<0)	 /* UART enabled */
74 
75 #define  UTS_FRCPERR	 (1<<13) /* Force parity error */
76 #define  UTS_LOOP        (1<<12) /* Loop tx and rx */
77 #define  UTS_TXEMPTY	 (1<<6)	 /* TxFIFO empty */
78 #define  UTS_RXEMPTY	 (1<<5)	 /* RxFIFO empty */
79 #define  UTS_TXFULL	 (1<<4)	 /* TxFIFO full */
80 #define  UTS_RXFULL	 (1<<3)	 /* RxFIFO full */
81 #define  UTS_SOFTRST	 (1<<0)	 /* Software reset */
82 
83 void imx_uart_init(vaddr_t __unused vbase)
84 {
85 	/*
86 	 * Do nothing, debug uart(uart0) share with normal world,
87 	 * everything for uart0 intialization is done in bootloader.
88 	 */
89 }
90 
91 void imx_uart_flush_tx_fifo(vaddr_t base)
92 {
93 	while (!(read32(base + UTS) & UTS_TXEMPTY))
94 		;
95 }
96 
97 int imx_uart_getchar(vaddr_t base)
98 {
99 	while (read32(base + UTS) & UTS_RXEMPTY)
100 		;
101 
102 	return (read32(base + URXD) & URXD_RX_DATA);
103 }
104 
105 void imx_uart_putc(const char c, vaddr_t base)
106 {
107 	write32(c, base + UTXD);
108 
109 	/* wait until sent */
110 	while (!(read32(base + UTS) & UTS_TXEMPTY))
111 		;
112 }
113