xref: /optee_os/core/drivers/imx_uart.c (revision 26267e8209dfae98152c7cea053067c24d4b5952)
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 <assert.h>
29 #include <drivers/imx_uart.h>
30 #include <io.h>
31 #include <util.h>
32 
33 /* Register definitions */
34 #define URXD  0x0  /* Receiver Register */
35 #define UTXD  0x40 /* Transmitter Register */
36 #define UCR1  0x80 /* Control Register 1 */
37 #define UCR2  0x84 /* Control Register 2 */
38 #define UCR3  0x88 /* Control Register 3 */
39 #define UCR4  0x8c /* Control Register 4 */
40 #define UFCR  0x90 /* FIFO Control Register */
41 #define USR1  0x94 /* Status Register 1 */
42 #define USR2  0x98 /* Status Register 2 */
43 #define UESC  0x9c /* Escape Character Register */
44 #define UTIM  0xa0 /* Escape Timer Register */
45 #define UBIR  0xa4 /* BRM Incremental Register */
46 #define UBMR  0xa8 /* BRM Modulator Register */
47 #define UBRC  0xac /* Baud Rate Count Register */
48 #define UTS   0xb4 /* UART Test Register (mx31) */
49 
50 /* UART Control Register Bit Fields.*/
51 #define  URXD_CHARRDY    (1<<15)
52 #define  URXD_ERR        (1<<14)
53 #define  URXD_OVRRUN     (1<<13)
54 #define  URXD_FRMERR     (1<<12)
55 #define  URXD_BRK        (1<<11)
56 #define  URXD_PRERR      (1<<10)
57 #define  URXD_RX_DATA    (0xFF)
58 #define  UCR1_ADEN       (1<<15) /* Auto dectect interrupt */
59 #define  UCR1_ADBR       (1<<14) /* Auto detect baud rate */
60 #define  UCR1_TRDYEN     (1<<13) /* Transmitter ready interrupt enable */
61 #define  UCR1_IDEN       (1<<12) /* Idle condition interrupt */
62 #define  UCR1_RRDYEN     (1<<9)	 /* Recv ready interrupt enable */
63 #define  UCR1_RDMAEN     (1<<8)	 /* Recv ready DMA enable */
64 #define  UCR1_IREN       (1<<7)	 /* Infrared interface enable */
65 #define  UCR1_TXMPTYEN   (1<<6)	 /* Transimitter empty interrupt enable */
66 #define  UCR1_RTSDEN     (1<<5)	 /* RTS delta interrupt enable */
67 #define  UCR1_SNDBRK     (1<<4)	 /* Send break */
68 #define  UCR1_TDMAEN     (1<<3)	 /* Transmitter ready DMA enable */
69 #define  UCR1_UARTCLKEN  (1<<2)	 /* UART clock enabled */
70 #define  UCR1_DOZE       (1<<1)	 /* Doze */
71 #define  UCR1_UARTEN     (1<<0)	 /* UART enabled */
72 
73 #define  UTS_FRCPERR	 (1<<13) /* Force parity error */
74 #define  UTS_LOOP        (1<<12) /* Loop tx and rx */
75 #define  UTS_TXEMPTY	 (1<<6)	 /* TxFIFO empty */
76 #define  UTS_RXEMPTY	 (1<<5)	 /* RxFIFO empty */
77 #define  UTS_TXFULL	 (1<<4)	 /* TxFIFO full */
78 #define  UTS_RXFULL	 (1<<3)	 /* RxFIFO full */
79 #define  UTS_SOFTRST	 (1<<0)	 /* Software reset */
80 
81 static vaddr_t chip_to_base(struct serial_chip *chip)
82 {
83 	struct imx_uart_data *pd =
84 		container_of(chip, struct imx_uart_data, chip);
85 
86 	return io_pa_or_va(&pd->base);
87 }
88 
89 static void imx_uart_flush(struct serial_chip *chip)
90 {
91 	vaddr_t base = chip_to_base(chip);
92 
93 	while (!(read32(base + UTS) & UTS_TXEMPTY))
94 		;
95 }
96 
97 static int imx_uart_getchar(struct serial_chip *chip)
98 {
99 	vaddr_t base = chip_to_base(chip);
100 
101 	while (read32(base + UTS) & UTS_RXEMPTY)
102 		;
103 
104 	return (read32(base + URXD) & URXD_RX_DATA);
105 }
106 
107 static void imx_uart_putc(struct serial_chip *chip, int ch)
108 {
109 	vaddr_t base = chip_to_base(chip);
110 
111 	write32(ch, base + UTXD);
112 
113 	/* Wait until sent */
114 	while (!(read32(base + UTS) & UTS_TXEMPTY))
115 		;
116 }
117 
118 static const struct serial_ops imx_uart_ops = {
119 	.flush = imx_uart_flush,
120 	.getchar = imx_uart_getchar,
121 	.putc = imx_uart_putc,
122 };
123 
124 void imx_uart_init(struct imx_uart_data *pd, paddr_t base)
125 {
126 	pd->base.pa = base;
127 	pd->chip.ops = &imx_uart_ops;
128 
129 	/*
130 	 * Do nothing, debug uart(uart0) share with normal world,
131 	 * everything for uart0 initialization is done in bootloader.
132 	 */
133 }
134