xref: /openbmc/u-boot/drivers/serial/serial_mxc.c (revision d984fed0)
1 /*
2  * (c) 2007 Sascha Hauer <s.hauer@pengutronix.de>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
17  *
18  */
19 
20 #include <common.h>
21 #ifdef CONFIG_MX31
22 #include <asm/arch/mx31.h>
23 #else
24 #include <asm/arch/imx-regs.h>
25 #include <asm/arch/clock.h>
26 #endif
27 
28 #define __REG(x)     (*((volatile u32 *)(x)))
29 
30 #ifdef CONFIG_SYS_MX31_UART1
31 #define UART_PHYS 0x43f90000
32 #elif defined(CONFIG_SYS_MX31_UART2)
33 #define UART_PHYS 0x43f94000
34 #elif defined(CONFIG_SYS_MX31_UART3)
35 #define UART_PHYS 0x5000c000
36 #elif defined(CONFIG_SYS_MX31_UART4)
37 #define UART_PHYS 0x43fb0000
38 #elif defined(CONFIG_SYS_MX31_UART5)
39 #define UART_PHYS 0x43fb4000
40 #elif defined(CONFIG_SYS_MX27_UART1)
41 #define UART_PHYS 0x1000a000
42 #elif defined(CONFIG_SYS_MX27_UART2)
43 #define UART_PHYS 0x1000b000
44 #elif defined(CONFIG_SYS_MX27_UART3)
45 #define UART_PHYS 0x1000c000
46 #elif defined(CONFIG_SYS_MX27_UART4)
47 #define UART_PHYS 0x1000d000
48 #elif defined(CONFIG_SYS_MX27_UART5)
49 #define UART_PHYS 0x1001b000
50 #elif defined(CONFIG_SYS_MX27_UART6)
51 #define UART_PHYS 0x1001c000
52 #else
53 #error "define CONFIG_SYS_MX31_UARTx to use the mx31 UART driver"
54 #endif
55 
56 /* Register definitions */
57 #define URXD  0x0  /* Receiver Register */
58 #define UTXD  0x40 /* Transmitter Register */
59 #define UCR1  0x80 /* Control Register 1 */
60 #define UCR2  0x84 /* Control Register 2 */
61 #define UCR3  0x88 /* Control Register 3 */
62 #define UCR4  0x8c /* Control Register 4 */
63 #define UFCR  0x90 /* FIFO Control Register */
64 #define USR1  0x94 /* Status Register 1 */
65 #define USR2  0x98 /* Status Register 2 */
66 #define UESC  0x9c /* Escape Character Register */
67 #define UTIM  0xa0 /* Escape Timer Register */
68 #define UBIR  0xa4 /* BRM Incremental Register */
69 #define UBMR  0xa8 /* BRM Modulator Register */
70 #define UBRC  0xac /* Baud Rate Count Register */
71 #define UTS   0xb4 /* UART Test Register (mx31) */
72 
73 /* UART Control Register Bit Fields.*/
74 #define  URXD_CHARRDY    (1<<15)
75 #define  URXD_ERR        (1<<14)
76 #define  URXD_OVRRUN     (1<<13)
77 #define  URXD_FRMERR     (1<<12)
78 #define  URXD_BRK        (1<<11)
79 #define  URXD_PRERR      (1<<10)
80 #define  URXD_RX_DATA    (0xFF)
81 #define  UCR1_ADEN       (1<<15) /* Auto dectect interrupt */
82 #define  UCR1_ADBR       (1<<14) /* Auto detect baud rate */
83 #define  UCR1_TRDYEN     (1<<13) /* Transmitter ready interrupt enable */
84 #define  UCR1_IDEN       (1<<12) /* Idle condition interrupt */
85 #define  UCR1_RRDYEN     (1<<9)	 /* Recv ready interrupt enable */
86 #define  UCR1_RDMAEN     (1<<8)	 /* Recv ready DMA enable */
87 #define  UCR1_IREN       (1<<7)	 /* Infrared interface enable */
88 #define  UCR1_TXMPTYEN   (1<<6)	 /* Transimitter empty interrupt enable */
89 #define  UCR1_RTSDEN     (1<<5)	 /* RTS delta interrupt enable */
90 #define  UCR1_SNDBRK     (1<<4)	 /* Send break */
91 #define  UCR1_TDMAEN     (1<<3)	 /* Transmitter ready DMA enable */
92 #define  UCR1_UARTCLKEN  (1<<2)	 /* UART clock enabled */
93 #define  UCR1_DOZE       (1<<1)	 /* Doze */
94 #define  UCR1_UARTEN     (1<<0)	 /* UART enabled */
95 #define  UCR2_ESCI	 (1<<15) /* Escape seq interrupt enable */
96 #define  UCR2_IRTS	 (1<<14) /* Ignore RTS pin */
97 #define  UCR2_CTSC	 (1<<13) /* CTS pin control */
98 #define  UCR2_CTS        (1<<12) /* Clear to send */
99 #define  UCR2_ESCEN      (1<<11) /* Escape enable */
100 #define  UCR2_PREN       (1<<8)  /* Parity enable */
101 #define  UCR2_PROE       (1<<7)  /* Parity odd/even */
102 #define  UCR2_STPB       (1<<6)	 /* Stop */
103 #define  UCR2_WS         (1<<5)	 /* Word size */
104 #define  UCR2_RTSEN      (1<<4)	 /* Request to send interrupt enable */
105 #define  UCR2_TXEN       (1<<2)	 /* Transmitter enabled */
106 #define  UCR2_RXEN       (1<<1)	 /* Receiver enabled */
107 #define  UCR2_SRST	 (1<<0)	 /* SW reset */
108 #define  UCR3_DTREN	 (1<<13) /* DTR interrupt enable */
109 #define  UCR3_PARERREN   (1<<12) /* Parity enable */
110 #define  UCR3_FRAERREN   (1<<11) /* Frame error interrupt enable */
111 #define  UCR3_DSR        (1<<10) /* Data set ready */
112 #define  UCR3_DCD        (1<<9)  /* Data carrier detect */
113 #define  UCR3_RI         (1<<8)  /* Ring indicator */
114 #define  UCR3_TIMEOUTEN  (1<<7)  /* Timeout interrupt enable */
115 #define  UCR3_RXDSEN	 (1<<6)  /* Receive status interrupt enable */
116 #define  UCR3_AIRINTEN   (1<<5)  /* Async IR wake interrupt enable */
117 #define  UCR3_AWAKEN	 (1<<4)  /* Async wake interrupt enable */
118 #define  UCR3_REF25	 (1<<3)  /* Ref freq 25 MHz */
119 #define  UCR3_REF30	 (1<<2)  /* Ref Freq 30 MHz */
120 #define  UCR3_INVT	 (1<<1)  /* Inverted Infrared transmission */
121 #define  UCR3_BPEN	 (1<<0)  /* Preset registers enable */
122 #define  UCR4_CTSTL_32   (32<<10) /* CTS trigger level (32 chars) */
123 #define  UCR4_INVR	 (1<<9)  /* Inverted infrared reception */
124 #define  UCR4_ENIRI	 (1<<8)  /* Serial infrared interrupt enable */
125 #define  UCR4_WKEN	 (1<<7)  /* Wake interrupt enable */
126 #define  UCR4_REF16	 (1<<6)  /* Ref freq 16 MHz */
127 #define  UCR4_IRSC	 (1<<5)  /* IR special case */
128 #define  UCR4_TCEN	 (1<<3)  /* Transmit complete interrupt enable */
129 #define  UCR4_BKEN	 (1<<2)  /* Break condition interrupt enable */
130 #define  UCR4_OREN	 (1<<1)  /* Receiver overrun interrupt enable */
131 #define  UCR4_DREN	 (1<<0)  /* Recv data ready interrupt enable */
132 #define  UFCR_RXTL_SHF   0       /* Receiver trigger level shift */
133 #define  UFCR_RFDIV      (7<<7)  /* Reference freq divider mask */
134 #define  UFCR_TXTL_SHF   10      /* Transmitter trigger level shift */
135 #define  USR1_PARITYERR  (1<<15) /* Parity error interrupt flag */
136 #define  USR1_RTSS	 (1<<14) /* RTS pin status */
137 #define  USR1_TRDY	 (1<<13) /* Transmitter ready interrupt/dma flag */
138 #define  USR1_RTSD	 (1<<12) /* RTS delta */
139 #define  USR1_ESCF	 (1<<11) /* Escape seq interrupt flag */
140 #define  USR1_FRAMERR    (1<<10) /* Frame error interrupt flag */
141 #define  USR1_RRDY       (1<<9)	 /* Receiver ready interrupt/dma flag */
142 #define  USR1_TIMEOUT    (1<<7)	 /* Receive timeout interrupt status */
143 #define  USR1_RXDS	 (1<<6)	 /* Receiver idle interrupt flag */
144 #define  USR1_AIRINT	 (1<<5)	 /* Async IR wake interrupt flag */
145 #define  USR1_AWAKE	 (1<<4)	 /* Aysnc wake interrupt flag */
146 #define  USR2_ADET	 (1<<15) /* Auto baud rate detect complete */
147 #define  USR2_TXFE	 (1<<14) /* Transmit buffer FIFO empty */
148 #define  USR2_DTRF	 (1<<13) /* DTR edge interrupt flag */
149 #define  USR2_IDLE	 (1<<12) /* Idle condition */
150 #define  USR2_IRINT	 (1<<8)	 /* Serial infrared interrupt flag */
151 #define  USR2_WAKE	 (1<<7)	 /* Wake */
152 #define  USR2_RTSF	 (1<<4)	 /* RTS edge interrupt flag */
153 #define  USR2_TXDC	 (1<<3)	 /* Transmitter complete */
154 #define  USR2_BRCD	 (1<<2)	 /* Break condition */
155 #define  USR2_ORE        (1<<1)	 /* Overrun error */
156 #define  USR2_RDR        (1<<0)	 /* Recv data ready */
157 #define  UTS_FRCPERR	 (1<<13) /* Force parity error */
158 #define  UTS_LOOP        (1<<12) /* Loop tx and rx */
159 #define  UTS_TXEMPTY	 (1<<6)	 /* TxFIFO empty */
160 #define  UTS_RXEMPTY	 (1<<5)	 /* RxFIFO empty */
161 #define  UTS_TXFULL	 (1<<4)	 /* TxFIFO full */
162 #define  UTS_RXFULL	 (1<<3)	 /* RxFIFO full */
163 #define  UTS_SOFTRST	 (1<<0)	 /* Software reset */
164 
165 DECLARE_GLOBAL_DATA_PTR;
166 
167 void serial_setbrg (void)
168 {
169 #ifdef CONFIG_MX31
170 	u32 clk = mx31_get_ipg_clk();
171 #else
172 	u32 clk = imx_get_perclk1();
173 #endif
174 
175 	if (!gd->baudrate)
176 		gd->baudrate = CONFIG_BAUDRATE;
177 
178 	__REG(UART_PHYS + UFCR) = 4 << 7; /* divide input clock by 2 */
179 	__REG(UART_PHYS + UBIR) = 0xf;
180 	__REG(UART_PHYS + UBMR) = clk / (2 * gd->baudrate);
181 
182 }
183 
184 int serial_getc (void)
185 {
186 	while (__REG(UART_PHYS + UTS) & UTS_RXEMPTY);
187 	return (__REG(UART_PHYS + URXD) & URXD_RX_DATA); /* mask out status from upper word */
188 }
189 
190 void serial_putc (const char c)
191 {
192 	__REG(UART_PHYS + UTXD) = c;
193 
194 	/* wait for transmitter to be ready */
195 	while(!(__REG(UART_PHYS + UTS) & UTS_TXEMPTY));
196 
197 	/* If \n, also do \r */
198 	if (c == '\n')
199 		serial_putc ('\r');
200 }
201 
202 /*
203  * Test whether a character is in the RX buffer
204  */
205 int serial_tstc (void)
206 {
207 	/* If receive fifo is empty, return false */
208 	if (__REG(UART_PHYS + UTS) & UTS_RXEMPTY)
209 		return 0;
210 	return 1;
211 }
212 
213 void
214 serial_puts (const char *s)
215 {
216 	while (*s) {
217 		serial_putc (*s++);
218 	}
219 }
220 
221 /*
222  * Initialise the serial port with the given baudrate. The settings
223  * are always 8 data bits, no parity, 1 stop bit, no start bits.
224  *
225  */
226 int serial_init (void)
227 {
228 	__REG(UART_PHYS + UCR1) = 0x0;
229 	__REG(UART_PHYS + UCR2) = 0x0;
230 
231 	while (!(__REG(UART_PHYS + UCR2) & UCR2_SRST));
232 
233 	__REG(UART_PHYS + UCR3) = 0x0704;
234 	__REG(UART_PHYS + UCR4) = 0x8000;
235 	__REG(UART_PHYS + UESC) = 0x002b;
236 	__REG(UART_PHYS + UTIM) = 0x0;
237 
238 	__REG(UART_PHYS + UTS) = 0x0;
239 
240 	serial_setbrg();
241 
242 	__REG(UART_PHYS + UCR2) = UCR2_WS | UCR2_IRTS | UCR2_RXEN | UCR2_TXEN | UCR2_SRST;
243 
244 	__REG(UART_PHYS + UCR1) = UCR1_UARTEN;
245 
246 	return 0;
247 }
248