xref: /haiku/src/system/kernel/arch/arm/arch_uart_pl011.cpp (revision 4c8e85b316c35a9161f5a1c50ad70bc91c83a76f)
1 /*
2  * Copyright 2011-2017 Haiku, Inc. All rights reserved.
3  * Distributed under the terms of the MIT License.
4  *
5  * Authors:
6  *		Alexander von Gluck, kallisti5@unixzen.com
7  */
8 
9 
10 #include <debug.h>
11 #include <arch/arm/reg.h>
12 #include <arch/generic/debug_uart.h>
13 #include <arch/arm/arch_uart_pl011.h>
14 #include <new>
15 
16 
17 #define PL01x_DR	0x00 // Data read or written
18 #define PL01x_RSR	0x04 // Receive status, read
19 #define PL01x_ECR	0x04 // Error clear, write
20 #define PL010_LCRH	0x08 // Line control, high
21 #define PL010_LCRM	0x0C // Line control, middle
22 #define PL010_LCRL	0x10 // Line control, low
23 #define PL010_CR	0x14 // Control
24 #define PL01x_FR	0x18 // Flag (r/o)
25 #define PL010_IIR	0x1C // Interrupt ID (r)
26 #define PL010_ICR	0x1C // Interrupt clear (w)
27 #define PL01x_ILPR	0x20 // IrDA low power
28 #define PL011_IBRD	0x24 // Interrupt baud rate divisor
29 #define PL011_FBRD	0x28 // Fractional baud rate divisor
30 #define PL011_LCRH	0x2C // Line control
31 #define PL011_CR	0x30 // Control
32 #define PL011_IFLS	0x34 // Interrupt fifo level
33 #define PL011_IMSC	0x38 // Interrupt mask
34 #define PL011_RIS	0x3C // Raw interrupt
35 #define PL011_MIS	0x40 // Masked interrupt
36 #define PL011_ICR	0x44 // Interrupt clear
37 #define PL011_DMACR	0x48 // DMA control register
38 
39 #define PL011_DR_OE		(1 << 11)
40 #define PL011_DR_BE		(1 << 10)
41 #define PL011_DR_PE		(1 << 9)
42 #define PL011_DR_FE		(1 << 8)
43 
44 #define PL01x_RSR_OE	0x08
45 #define PL01x_RSR_BE	0x04
46 #define PL01x_RSR_PE	0x02
47 #define PL01x_RSR_FE	0x01
48 
49 #define PL011_FR_RI		0x100
50 #define PL011_FR_TXFE	0x080
51 #define PL011_FR_RXFF	0x040
52 #define PL01x_FR_TXFF	0x020
53 #define PL01x_FR_RXFE	0x010
54 #define PL01x_FR_BUSY	0x008
55 #define PL01x_FR_DCD	0x004
56 #define PL01x_FR_DSR	0x002
57 #define PL01x_FR_CTS	0x001
58 #define PL01x_FR_TMSK	(PL01x_FR_TXFF | PL01x_FR_BUSY)
59 
60 #define PL011_CR_CTSEN	0x8000 // CTS flow control
61 #define PL011_CR_RTSEN	0x4000 // RTS flow control
62 #define PL011_CR_OUT2	0x2000 // OUT2
63 #define PL011_CR_OUT1	0x1000 // OUT1
64 #define PL011_CR_RTS	0x0800 // RTS
65 #define PL011_CR_DTR	0x0400 // DTR
66 #define PL011_CR_RXE	0x0200 // Receive enable
67 #define PL011_CR_TXE	0x0100 // Transmit enable
68 #define PL011_CR_LBE	0x0080 // Loopback enable
69 #define PL010_CR_RTIE	0x0040
70 #define PL010_CR_TIE	0x0020
71 #define PL010_CR_RIE	0x0010
72 #define PL010_CR_MSIE	0x0008
73 #define PL01x_CR_IIRLP	0x0004 // SIR low power mode
74 #define PL01x_CR_SIREN	0x0002 // SIR enable
75 #define PL01x_CR_UARTEN 0x0001 // UART enable
76 
77 #define PL011_LCRH_SPS		0x80
78 #define PL01x_LCRH_WLEN_8	0x60
79 #define PL01x_LCRH_WLEN_7	0x40
80 #define PL01x_LCRH_WLEN_6	0x20
81 #define PL01x_LCRH_WLEN_5	0x00
82 #define PL01x_LCRH_FEN		0x10
83 #define PL01x_LCRH_STP2		0x08
84 #define PL01x_LCRH_EPS		0x04
85 #define PL01x_LCRH_PEN		0x02
86 #define PL01x_LCRH_BRK		0x01
87 
88 #define PL010_IIR_RTIS	0x08
89 #define PL010_IIR_TIS	0x04
90 #define PL010_IIR_RIS	0x02
91 #define PL010_IIR_MIS	0x01
92 
93 #define PL011_IFLS_RX1_8	(0 << 3)
94 #define PL011_IFLS_RX2_8	(1 << 3)
95 #define PL011_IFLS_RX4_8	(2 << 3)
96 #define PL011_IFLS_RX6_8	(3 << 3)
97 #define PL011_IFLS_RX7_8	(4 << 3)
98 #define PL011_IFLS_TX1_8	(0 << 0)
99 #define PL011_IFLS_TX2_8	(1 << 0)
100 #define PL011_IFLS_TX4_8	(2 << 0)
101 #define PL011_IFLS_TX6_8	(3 << 0)
102 #define PL011_IFLS_TX7_8	(4 << 0)
103 
104 #define PL011_IFLS_RX_HALF	(5 << 3) // ST vendor only
105 #define PL011_IFLS_TX_HALF	(5 << 0) // ST vendor only
106 
107 #define PL011_OEIM		(1 << 10) // overrun error interrupt mask
108 #define PL011_BEIM		(1 << 9) // break error interrupt mask
109 #define PL011_PEIM		(1 << 8) // parity error interrupt mask
110 #define PL011_FEIM		(1 << 7) // framing error interrupt mask
111 #define PL011_RTIM		(1 << 6) // receive timeout interrupt mask
112 #define PL011_TXIM		(1 << 5) // transmit interrupt mask
113 #define PL011_RXIM		(1 << 4) // receive interrupt mask
114 #define PL011_DSRMIM	(1 << 3) // DSR interrupt mask
115 #define PL011_DCDMIM	(1 << 2) // DCD interrupt mask
116 #define PL011_CTSMIM	(1 << 1) // CTS interrupt mask
117 #define PL011_RIMIM		(1 << 0) // RI interrupt mask
118 #define PL011_MSKIM		0x7ff	 // Mask all interrupts
119 
120 #define PL011_OEIS		(1 << 10) // overrun error interrupt state
121 #define PL011_BEIS		(1 << 9) // break error interrupt state
122 #define PL011_PEIS		(1 << 8) // parity error interrupt state
123 #define PL011_FEIS		(1 << 7) // framing error interrupt	state
124 #define PL011_RTIS		(1 << 6) // receive timeout interrupt state
125 #define PL011_TXIS		(1 << 5) // transmit interrupt state
126 #define PL011_RXIS		(1 << 4) // receive interrupt state
127 #define PL011_DSRMIS	(1 << 3) // DSR interrupt state
128 #define PL011_DCDMIS	(1 << 2) // DCD interrupt state
129 #define PL011_CTSMIS	(1 << 1) // CTS interrupt state
130 #define PL011_RIMIS		(1 << 0) // RI interrupt state
131 
132 #define PL011_OEIC		(1 << 10) // overrun error interrupt clear
133 #define PL011_BEIC		(1 << 9) // break error interrupt clear
134 #define PL011_PEIC		(1 << 8) // parity error interrupt clear
135 #define PL011_FEIC		(1 << 7) // framing error interrupt clear
136 #define PL011_RTIC		(1 << 6) // receive timeout interrupt clear
137 #define PL011_TXIC		(1 << 5) // transmit interrupt clear
138 #define PL011_RXIC		(1 << 4) // receive interrupt clear
139 #define PL011_DSRMIC	(1 << 3) // DSR interrupt clear
140 #define PL011_DCDMIC	(1 << 2) // DCD interrupt clear
141 #define PL011_CTSMIC	(1 << 1) // CTS interrupt clear
142 #define PL011_RIMIC		(1 << 0) // RI interrupt clear
143 
144 #define PL011_DMAONERR	(1 << 2) // disable dma on err
145 #define PL011_TXDMAE	(1 << 1) // enable transmit dma
146 #define PL011_RXDMAE	(1 << 0) // enable receive dma
147 
148 
149 ArchUARTPL011::ArchUARTPL011(addr_t base, int64 clock)
150 	:
151 	DebugUART(base, clock)
152 {
153 	Barrier();
154 
155 	// ** Loopback test
156 	uint32 cr = PL01x_CR_UARTEN;
157 		// Enable UART
158 	cr |= PL011_CR_TXE;
159 		// Enable TX
160 	cr |= PL011_CR_LBE;
161 		// Enable Loopback mode
162 	Out32(PL011_CR, cr);
163 
164 	Out32(PL011_FBRD, 0);
165 	Out32(PL011_IBRD, 1);
166 	Out32(PL011_LCRH, 0); // TODO: ST is different tx, rx lcr
167 
168 	// Write a 0 to the port and wait for confim..
169 	Out32(PL01x_DR, 0);
170 
171 	while (In32(PL01x_FR) & PL01x_FR_BUSY)
172 		Barrier();
173 
174 	// ** Disable loopback, enable uart
175 	cr = PL01x_CR_UARTEN | PL011_CR_RXE | PL011_CR_TXE;
176 	Out32(PL011_CR, cr);
177 
178 	// ** Clear interrupts
179 	Out32(PL011_ICR, PL011_OEIS | PL011_BEIS
180 		| PL011_PEIS | PL011_FEIS);
181 
182 	// ** Disable interrupts
183 	Out32(PL011_IMSC, In32(PL011_IMSC) & ~PL011_MSKIM);
184 }
185 
186 
187 ArchUARTPL011::~ArchUARTPL011()
188 {
189 }
190 
191 
192 void
193 ArchUARTPL011::Out32(int reg, uint32 data)
194 {
195 	*(volatile uint32*)(Base() + reg) = data;
196 }
197 
198 
199 uint32
200 ArchUARTPL011::In32(int reg)
201 {
202 	return *(volatile uint32*)(Base() + reg);
203 }
204 
205 
206 void
207 ArchUARTPL011::Barrier()
208 {
209 	asm volatile ("" : : : "memory");
210 }
211 
212 
213 void
214 ArchUARTPL011::InitPort(uint32 baud)
215 {
216 	// Calculate baud divisor
217 	uint32 baudDivisor = Clock() / (16 * baud);
218 	uint32 remainder = Clock() % (16 * baud);
219 	uint32 baudFractional = ((8 * remainder) / baud >> 1)
220 		+ ((8 * remainder) / baud & 1);
221 
222 	// Disable UART
223 	Disable();
224 
225 	// Set baud divisor
226 	Out32(PL011_IBRD, baudDivisor);
227 	Out32(PL011_FBRD, baudFractional);
228 
229 	// Set LCR 8n1, enable fifo
230 	Out32(PL011_LCRH, (In32(PL011_LCRH) & ~0xff)
231 		| PL01x_LCRH_WLEN_8 | PL01x_LCRH_FEN);
232 
233 	// Set FIFO levels
234 	Out32(PL011_IFLS, PL011_IFLS_RX4_8 | PL011_IFLS_TX4_8);
235 
236 	// Enable UART
237 	Enable();
238 }
239 
240 
241 void
242 ArchUARTPL011::InitEarly()
243 {
244 	// Perform special hardware UART configuration
245 }
246 
247 
248 void
249 ArchUARTPL011::Enable()
250 {
251 	uint32 cr = PL01x_CR_UARTEN;
252 		// Enable UART
253 	cr |= PL011_CR_TXE | PL011_CR_RXE;
254 		// Enable TX and RX
255 
256 	Out32(PL011_CR, cr);
257 
258 	DebugUART::Enable();
259 }
260 
261 
262 void
263 ArchUARTPL011::Disable()
264 {
265 	// Disable everything
266 	Out32(PL011_CR, 0);
267 
268 	DebugUART::Disable();
269 }
270 
271 
272 int
273 ArchUARTPL011::PutChar(char c)
274 {
275 	if (Enabled() == true) {
276 		// Wait until there is room in fifo
277 		while ((In32(PL01x_FR) & PL01x_FR_TXFF) != 0)
278 			Barrier();
279 
280 		Out32(PL01x_DR, c);
281 		return 0;
282 	}
283 
284 	return -1;
285 }
286 
287 
288 int
289 ArchUARTPL011::GetChar(bool wait)
290 {
291 	if (Enabled() == true) {
292 		if (wait) {
293 			// Wait until a character is received
294 			while ((In32(PL01x_FR) & PL01x_FR_RXFE) != 0)
295 				Barrier();
296 		} else {
297 			// Check if there is any data available in RX fifo
298 			if ((In32(PL01x_FR) & PL01x_FR_RXFE) != 0)
299 				return -1;
300 		}
301 		return In32(PL01x_DR);
302 	}
303 
304 	return -1;
305 }
306 
307 
308 void
309 ArchUARTPL011::FlushTx()
310 {
311 	// Wait until transmit fifo empty
312 	while ((In32(PL01x_FR) & PL011_FR_TXFE) == 0)
313 		Barrier();
314 }
315 
316 
317 void
318 ArchUARTPL011::FlushRx()
319 {
320 	// Wait until receive fifo empty
321 	while ((In32(PL01x_FR) & PL01x_FR_RXFE) == 0)
322 		Barrier();
323 }
324 
325 
326 ArchUARTPL011*
327 arch_get_uart_pl011(addr_t base, int64 clock)
328 {
329 	static char buffer[sizeof(ArchUARTPL011)];
330 	ArchUARTPL011 *uart = new(buffer) ArchUARTPL011(base, clock);
331 	return uart;
332 }
333