1 /*
2  * NS16550 Serial Port
3  * originally from linux source (arch/powerpc/boot/ns16550.h)
4  *
5  * Cleanup and unification
6  * (C) 2009 by Detlev Zundel, DENX Software Engineering GmbH
7  *
8  * modified slightly to
9  * have addresses as offsets from CONFIG_SYS_ISA_BASE
10  * added a few more definitions
11  * added prototypes for ns16550.c
12  * reduced no of com ports to 2
13  * modifications (c) Rob Taylor, Flying Pig Systems. 2000.
14  *
15  * added support for port on 64-bit bus
16  * by Richard Danter (richard.danter@windriver.com), (C) 2005 Wind River Systems
17  */
18 
19 /*
20  * Note that the following macro magic uses the fact that the compiler
21  * will not allocate storage for arrays of size 0
22  */
23 
24 #ifndef __ns16550_h
25 #define __ns16550_h
26 
27 #include <linux/types.h>
28 
29 #if CONFIG_IS_ENABLED(DM_SERIAL) ||  defined(CONFIG_NS16550_DYNAMIC) || \
30 	defined(CONFIG_DEBUG_UART)
31 /*
32  * For driver model we always use one byte per register, and sort out the
33  * differences in the driver. In the case of CONFIG_NS16550_DYNAMIC we do
34  * similar, and CONFIG_DEBUG_UART is responsible for shifts in its own manner.
35  */
36 #define UART_REG(x)	unsigned char x
37 #else
38 #if !defined(CONFIG_SYS_NS16550_REG_SIZE) || (CONFIG_SYS_NS16550_REG_SIZE == 0)
39 #error "Please define NS16550 registers size."
40 #elif (CONFIG_SYS_NS16550_REG_SIZE > 0)
41 #define UART_REG(x)						   \
42 	unsigned char prepad_##x[CONFIG_SYS_NS16550_REG_SIZE - 1]; \
43 	unsigned char x;
44 #elif (CONFIG_SYS_NS16550_REG_SIZE < 0)
45 #define UART_REG(x)							\
46 	unsigned char x;						\
47 	unsigned char postpad_##x[-CONFIG_SYS_NS16550_REG_SIZE - 1];
48 #endif
49 #endif /* CONFIG_NS16550_DYNAMIC */
50 
51 enum ns16550_flags {
52 	NS16550_FLAG_IO		= 1 << 0, /* Use I/O access (else mem-mapped) */
53 	NS16550_FLAG_ENDIAN	= 1 << 1, /* Use out_le/be_32() */
54 	NS16550_FLAG_BE		= 1 << 2, /* Big-endian access (else little) */
55 };
56 
57 /**
58  * struct ns16550_plat - information about a NS16550 port
59  *
60  * @base:		Base register address
61  * @reg_width:		IO accesses size of registers (in bytes, 1 or 4)
62  * @reg_shift:		Shift size of registers (0=byte, 1=16bit, 2=32bit...)
63  * @reg_offset:		Offset to start of registers (normally 0)
64  * @clock:		UART base clock speed in Hz
65  * @fcr:		Offset of FCR register (normally UART_FCR_DEFVAL)
66  * @flags:		A few flags (enum ns16550_flags)
67  * @bdf:		PCI slot/function (pci_dev_t)
68  */
69 struct ns16550_plat {
70 	unsigned long base;
71 	int reg_width;
72 	int reg_shift;
73 	int reg_offset;
74 	int clock;
75 	u32 fcr;
76 	int flags;
77 #if defined(CONFIG_PCI) && defined(CONFIG_SPL)
78 	int bdf;
79 #endif
80 };
81 
82 struct udevice;
83 
84 struct ns16550 {
85 	UART_REG(rbr);		/* 0 */
86 	UART_REG(ier);		/* 1 */
87 	UART_REG(fcr);		/* 2 */
88 	UART_REG(lcr);		/* 3 */
89 	UART_REG(mcr);		/* 4 */
90 	UART_REG(lsr);		/* 5 */
91 	UART_REG(msr);		/* 6 */
92 	UART_REG(spr);		/* 7 */
93 #ifdef CONFIG_SOC_DA8XX
94 	UART_REG(reg8);		/* 8 */
95 	UART_REG(reg9);		/* 9 */
96 	UART_REG(revid1);	/* A */
97 	UART_REG(revid2);	/* B */
98 	UART_REG(pwr_mgmt);	/* C */
99 	UART_REG(mdr1);		/* D */
100 #else
101 	UART_REG(mdr1);		/* 8 */
102 	UART_REG(reg9);		/* 9 */
103 	UART_REG(regA);		/* A */
104 	UART_REG(regB);		/* B */
105 	UART_REG(regC);		/* C */
106 	UART_REG(regD);		/* D */
107 	UART_REG(regE);		/* E */
108 	UART_REG(uasr);		/* F */
109 	UART_REG(scr);		/* 10*/
110 	UART_REG(ssr);		/* 11*/
111 #endif
112 #if CONFIG_IS_ENABLED(DM_SERIAL)
113 	struct ns16550_plat *plat;
114 #endif
115 };
116 
117 #define thr rbr
118 #define iir fcr
119 #define dll rbr
120 #define dlm ier
121 
122 /*
123  * These are the definitions for the FIFO Control Register
124  */
125 #define UART_FCR_FIFO_EN	0x01 /* Fifo enable */
126 #define UART_FCR_CLEAR_RCVR	0x02 /* Clear the RCVR FIFO */
127 #define UART_FCR_CLEAR_XMIT	0x04 /* Clear the XMIT FIFO */
128 #define UART_FCR_DMA_SELECT	0x08 /* For DMA applications */
129 #define UART_FCR_TRIGGER_MASK	0xC0 /* Mask for the FIFO trigger range */
130 #define UART_FCR_TRIGGER_1	0x00 /* Mask for trigger set at 1 */
131 #define UART_FCR_TRIGGER_4	0x40 /* Mask for trigger set at 4 */
132 #define UART_FCR_TRIGGER_8	0x80 /* Mask for trigger set at 8 */
133 #define UART_FCR_TRIGGER_14	0xC0 /* Mask for trigger set at 14 */
134 
135 #define UART_FCR_RXSR		0x02 /* Receiver soft reset */
136 #define UART_FCR_TXSR		0x04 /* Transmitter soft reset */
137 
138 /* Ingenic JZ47xx specific UART-enable bit. */
139 #define UART_FCR_UME		0x10
140 
141 /* Clear & enable FIFOs */
142 #define UART_FCR_DEFVAL (UART_FCR_FIFO_EN | \
143 			UART_FCR_RXSR |	\
144 			UART_FCR_TXSR)
145 
146 /*
147  * These are the definitions for the Modem Control Register
148  */
149 #define UART_MCR_DTR	0x01		/* DTR   */
150 #define UART_MCR_RTS	0x02		/* RTS   */
151 #define UART_MCR_OUT1	0x04		/* Out 1 */
152 #define UART_MCR_OUT2	0x08		/* Out 2 */
153 #define UART_MCR_LOOP	0x10		/* Enable loopback test mode */
154 #define UART_MCR_AFE	0x20		/* Enable auto-RTS/CTS */
155 
156 #define UART_MCR_DMA_EN	0x04
157 #define UART_MCR_TX_DFR	0x08
158 
159 /*
160  * These are the definitions for the Line Control Register
161  *
162  * Note: if the word length is 5 bits (UART_LCR_WLEN5), then setting
163  * UART_LCR_STOP will select 1.5 stop bits, not 2 stop bits.
164  */
165 #define UART_LCR_WLS_MSK 0x03		/* character length select mask */
166 #define UART_LCR_WLS_5	0x00		/* 5 bit character length */
167 #define UART_LCR_WLS_6	0x01		/* 6 bit character length */
168 #define UART_LCR_WLS_7	0x02		/* 7 bit character length */
169 #define UART_LCR_WLS_8	0x03		/* 8 bit character length */
170 #define UART_LCR_STB	0x04		/* # stop Bits, off=1, on=1.5 or 2) */
171 #define UART_LCR_PEN	0x08		/* Parity eneble */
172 #define UART_LCR_EPS	0x10		/* Even Parity Select */
173 #define UART_LCR_STKP	0x20		/* Stick Parity */
174 #define UART_LCR_SBRK	0x40		/* Set Break */
175 #define UART_LCR_BKSE	0x80		/* Bank select enable */
176 #define UART_LCR_DLAB	0x80		/* Divisor latch access bit */
177 
178 /*
179  * These are the definitions for the Line Status Register
180  */
181 #define UART_LSR_DR	0x01		/* Data ready */
182 #define UART_LSR_OE	0x02		/* Overrun */
183 #define UART_LSR_PE	0x04		/* Parity error */
184 #define UART_LSR_FE	0x08		/* Framing error */
185 #define UART_LSR_BI	0x10		/* Break */
186 #define UART_LSR_THRE	0x20		/* Xmit holding register empty */
187 #define UART_LSR_TEMT	0x40		/* Xmitter empty */
188 #define UART_LSR_ERR	0x80		/* Error */
189 
190 #define UART_MSR_DCD	0x80		/* Data Carrier Detect */
191 #define UART_MSR_RI	0x40		/* Ring Indicator */
192 #define UART_MSR_DSR	0x20		/* Data Set Ready */
193 #define UART_MSR_CTS	0x10		/* Clear to Send */
194 #define UART_MSR_DDCD	0x08		/* Delta DCD */
195 #define UART_MSR_TERI	0x04		/* Trailing edge ring indicator */
196 #define UART_MSR_DDSR	0x02		/* Delta DSR */
197 #define UART_MSR_DCTS	0x01		/* Delta CTS */
198 
199 /*
200  * These are the definitions for the Interrupt Identification Register
201  */
202 #define UART_IIR_NO_INT	0x01	/* No interrupts pending */
203 #define UART_IIR_ID	0x06	/* Mask for the interrupt ID */
204 
205 #define UART_IIR_MSI	0x00	/* Modem status interrupt */
206 #define UART_IIR_THRI	0x02	/* Transmitter holding register empty */
207 #define UART_IIR_RDI	0x04	/* Receiver data interrupt */
208 #define UART_IIR_RLSI	0x06	/* Receiver line status interrupt */
209 
210 /*
211  * These are the definitions for the Interrupt Enable Register
212  */
213 #define UART_IER_MSI	0x08	/* Enable Modem status interrupt */
214 #define UART_IER_RLSI	0x04	/* Enable receiver line status interrupt */
215 #define UART_IER_THRI	0x02	/* Enable Transmitter holding register int. */
216 #define UART_IER_RDI	0x01	/* Enable receiver data interrupt */
217 
218 /* useful defaults for LCR */
219 #define UART_LCR_8N1	0x03
220 
221 void ns16550_init(struct ns16550 *com_port, int baud_divisor);
222 void ns16550_putc(struct ns16550 *com_port, char c);
223 char ns16550_getc(struct ns16550 *com_port);
224 int ns16550_tstc(struct ns16550 *com_port);
225 void ns16550_reinit(struct ns16550 *com_port, int baud_divisor);
226 
227 /**
228  * ns16550_calc_divisor() - calculate the divisor given clock and baud rate
229  *
230  * Given the UART input clock and required baudrate, calculate the divisor
231  * that should be used.
232  *
233  * @port:	UART port
234  * @clock:	UART input clock speed in Hz
235  * @baudrate:	Required baud rate
236  * Return: baud rate divisor that should be used
237  */
238 int ns16550_calc_divisor(struct ns16550 *port, int clock, int baudrate);
239 
240 /**
241  * ns16550_serial_of_to_plat() - convert DT to platform data
242  *
243  * Decode a device tree node for an ns16550 device. This includes the
244  * register base address and register shift properties. The caller must set
245  * up the clock frequency.
246  *
247  * @dev:	dev to decode platform data for
248  * @return:	0 if OK, -EINVAL on error
249  */
250 int ns16550_serial_of_to_plat(struct udevice *dev);
251 
252 /**
253  * ns16550_serial_probe() - probe a serial port
254  *
255  * This sets up the serial port ready for use, except for the baud rate
256  * Return: 0, or -ve on error
257  */
258 int ns16550_serial_probe(struct udevice *dev);
259 
260 /**
261  * struct ns16550_serial_ops - ns16550 serial operations
262  *
263  * These should be used by the client driver for the driver's 'ops' member
264  */
265 extern const struct dm_serial_ops ns16550_serial_ops;
266 
267 #endif /* __ns16550_h */
268