1 /*
2  * Copyright 2003-2011 NetLogic Microsystems, Inc. (NetLogic). All rights
3  * reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the NetLogic
9  * license below:
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  *
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in
19  *    the documentation and/or other materials provided with the
20  *    distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY NETLOGIC ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
24  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED. IN NO EVENT SHALL NETLOGIC OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
29  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
30  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
31  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
32  * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 #ifndef __XLP_HAL_UART_H__
36 #define __XLP_HAL_UART_H__
37 
38 /* UART Specific registers */
39 #define UART_RX_DATA		0x00
40 #define UART_TX_DATA		0x00
41 
42 #define UART_INT_EN		0x01
43 #define UART_INT_ID		0x02
44 #define UART_FIFO_CTL		0x02
45 #define UART_LINE_CTL		0x03
46 #define UART_MODEM_CTL		0x04
47 #define UART_LINE_STS		0x05
48 #define UART_MODEM_STS		0x06
49 
50 #define UART_DIVISOR0		0x00
51 #define UART_DIVISOR1		0x01
52 
53 #define BASE_BAUD		(XLP_IO_CLK/16)
54 #define BAUD_DIVISOR(baud)	(BASE_BAUD / baud)
55 
56 /* LCR mask values */
57 #define LCR_5BITS		0x00
58 #define LCR_6BITS		0x01
59 #define LCR_7BITS		0x02
60 #define LCR_8BITS		0x03
61 #define LCR_STOPB		0x04
62 #define LCR_PENAB		0x08
63 #define LCR_PODD		0x00
64 #define LCR_PEVEN		0x10
65 #define LCR_PONE		0x20
66 #define LCR_PZERO		0x30
67 #define LCR_SBREAK		0x40
68 #define LCR_EFR_ENABLE		0xbf
69 #define LCR_DLAB		0x80
70 
71 /* MCR mask values */
72 #define MCR_DTR			0x01
73 #define MCR_RTS			0x02
74 #define MCR_DRS			0x04
75 #define MCR_IE			0x08
76 #define MCR_LOOPBACK		0x10
77 
78 /* FCR mask values */
79 #define FCR_RCV_RST		0x02
80 #define FCR_XMT_RST		0x04
81 #define FCR_RX_LOW		0x00
82 #define FCR_RX_MEDL		0x40
83 #define FCR_RX_MEDH		0x80
84 #define FCR_RX_HIGH		0xc0
85 
86 /* IER mask values */
87 #define IER_ERXRDY		0x1
88 #define IER_ETXRDY		0x2
89 #define IER_ERLS		0x4
90 #define IER_EMSC		0x8
91 
92 #if !defined(LOCORE) && !defined(__ASSEMBLY__)
93 
94 #define nlm_read_uart_reg(b, r)		nlm_read_reg(b, r)
95 #define nlm_write_uart_reg(b, r, v)	nlm_write_reg(b, r, v)
96 #define nlm_get_uart_pcibase(node, inst)	\
97 	nlm_pcicfg_base(cpu_is_xlp9xx() ?  XLP9XX_IO_UART_OFFSET(node) : \
98 						XLP_IO_UART_OFFSET(node, inst))
99 #define nlm_get_uart_regbase(node, inst)	\
100 			(nlm_get_uart_pcibase(node, inst) + XLP_IO_PCI_HDRSZ)
101 
102 static inline void
nlm_uart_set_baudrate(uint64_t base,int baud)103 nlm_uart_set_baudrate(uint64_t base, int baud)
104 {
105 	uint32_t lcr;
106 
107 	lcr = nlm_read_uart_reg(base, UART_LINE_CTL);
108 
109 	/* enable divisor register, and write baud values */
110 	nlm_write_uart_reg(base, UART_LINE_CTL, lcr | (1 << 7));
111 	nlm_write_uart_reg(base, UART_DIVISOR0,
112 			(BAUD_DIVISOR(baud) & 0xff));
113 	nlm_write_uart_reg(base, UART_DIVISOR1,
114 			((BAUD_DIVISOR(baud) >> 8) & 0xff));
115 
116 	/* restore default lcr */
117 	nlm_write_uart_reg(base, UART_LINE_CTL, lcr);
118 }
119 
120 static inline void
nlm_uart_outbyte(uint64_t base,char c)121 nlm_uart_outbyte(uint64_t base, char c)
122 {
123 	uint32_t lsr;
124 
125 	for (;;) {
126 		lsr = nlm_read_uart_reg(base, UART_LINE_STS);
127 		if (lsr & 0x20)
128 			break;
129 	}
130 
131 	nlm_write_uart_reg(base, UART_TX_DATA, (int)c);
132 }
133 
134 static inline char
nlm_uart_inbyte(uint64_t base)135 nlm_uart_inbyte(uint64_t base)
136 {
137 	int data, lsr;
138 
139 	for (;;) {
140 		lsr = nlm_read_uart_reg(base, UART_LINE_STS);
141 		if (lsr & 0x80) { /* parity/frame/break-error - push a zero */
142 			data = 0;
143 			break;
144 		}
145 		if (lsr & 0x01) {	/* Rx data */
146 			data = nlm_read_uart_reg(base, UART_RX_DATA);
147 			break;
148 		}
149 	}
150 
151 	return (char)data;
152 }
153 
154 static inline int
nlm_uart_init(uint64_t base,int baud,int databits,int stopbits,int parity,int int_en,int loopback)155 nlm_uart_init(uint64_t base, int baud, int databits, int stopbits,
156 	int parity, int int_en, int loopback)
157 {
158 	uint32_t lcr;
159 
160 	lcr = 0;
161 	if (databits >= 8)
162 		lcr |= LCR_8BITS;
163 	else if (databits == 7)
164 		lcr |= LCR_7BITS;
165 	else if (databits == 6)
166 		lcr |= LCR_6BITS;
167 	else
168 		lcr |= LCR_5BITS;
169 
170 	if (stopbits > 1)
171 		lcr |= LCR_STOPB;
172 
173 	lcr |= parity << 3;
174 
175 	/* setup default lcr */
176 	nlm_write_uart_reg(base, UART_LINE_CTL, lcr);
177 
178 	/* Reset the FIFOs */
179 	nlm_write_uart_reg(base, UART_LINE_CTL, FCR_RCV_RST | FCR_XMT_RST);
180 
181 	nlm_uart_set_baudrate(base, baud);
182 
183 	if (loopback)
184 		nlm_write_uart_reg(base, UART_MODEM_CTL, 0x1f);
185 
186 	if (int_en)
187 		nlm_write_uart_reg(base, UART_INT_EN, IER_ERXRDY | IER_ETXRDY);
188 
189 	return 0;
190 }
191 #endif /* !LOCORE && !__ASSEMBLY__ */
192 #endif /* __XLP_HAL_UART_H__ */
193