1 /*
2 * Copyright (c) 2006-2024 RT-Thread Development Team
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 *
6 * Change Logs:
7 * Date Author Notes
8 * 2022-11-16 GuEe-GUI first version
9 */
10
11 #include "8250.h"
12
13 struct serial8250 early_serial8250 = { 0 };
14
serial8250_early_in(struct serial8250 * serial,int offset)15 static rt_uint32_t serial8250_early_in(struct serial8250 *serial, int offset)
16 {
17 return serial8250_in(serial, offset);
18 }
19
serial8250_early_out(struct serial8250 * serial,int offset,int value)20 static void serial8250_early_out(struct serial8250 *serial, int offset, int value)
21 {
22 serial8250_out(serial, offset, value);
23 }
24
serial8250_early_putc(struct rt_serial_device * raw_serial,char c)25 int serial8250_early_putc(struct rt_serial_device *raw_serial, char c)
26 {
27 if (raw_serial)
28 {
29 /* FIFO and shifting register empty */
30 const int uart_lsr_both_empty = (UART_LSR_TEMT | UART_LSR_THRE);
31 struct serial8250 *serial = rt_container_of(raw_serial, struct serial8250, parent);
32
33 serial8250_early_out(serial, UART_TX, c);
34
35 while ((serial8250_early_in(serial, UART_LSR) & uart_lsr_both_empty) != uart_lsr_both_empty)
36 {
37 rt_hw_cpu_relax();
38 }
39 }
40
41 return 1;
42 }
43
init_serial(struct serial8250 * serial)44 static void init_serial(struct serial8250 *serial)
45 {
46 unsigned char c;
47 rt_uint32_t ier, divisor;
48
49 serial8250_early_out(serial, UART_LCR, 0x3); /* 8n1 */
50 ier = serial8250_early_in(serial, UART_IER);
51 serial8250_early_out(serial, UART_IER, ier & UART_IER_UUE); /* no interrupt */
52 serial8250_early_out(serial, UART_FCR, 0); /* no fifo */
53 serial8250_early_out(serial, UART_MCR, 0x3); /* DTR + RTS */
54
55 if (serial->freq)
56 {
57 divisor = RT_DIV_ROUND_CLOSEST(serial->freq, 16 * serial->parent.config.baud_rate);
58 c = serial8250_early_in(serial, UART_LCR);
59 serial8250_early_out(serial, UART_LCR, c | UART_LCR_DLAB);
60 serial8250_early_out(serial, UART_DLL, divisor & 0xff);
61 serial8250_early_out(serial, UART_DLM, (divisor >> 8) & 0xff);
62 serial8250_early_out(serial, UART_LCR, c & ~UART_LCR_DLAB);
63 }
64 }
65
serial8250_early_kick(struct rt_fdt_earlycon * con,int why)66 static void serial8250_early_kick(struct rt_fdt_earlycon *con, int why)
67 {
68 struct serial8250 *serial = raw_to_serial8250(con->data);
69
70 switch (why)
71 {
72 case FDT_EARLYCON_KICK_UPDATE:
73 serial->base = rt_ioremap((void *)con->mmio, con->size);
74 break;
75
76 case FDT_EARLYCON_KICK_COMPLETED:
77 rt_iounmap(serial->base);
78 break;
79
80 default:
81 break;
82 }
83 }
84
serial8250_early_fdt_setup(struct serial8250 * serial,struct rt_fdt_earlycon * con,const char * options)85 rt_err_t serial8250_early_fdt_setup(struct serial8250 *serial, struct rt_fdt_earlycon *con, const char *options)
86 {
87 rt_err_t ret = RT_EOK;
88
89 if (!serial->base && con)
90 {
91 serial8250_config(serial, options);
92 con->mmio = (rt_ubase_t)serial->base;
93 con->size = serial->size;
94 }
95
96 if (serial->base && con)
97 {
98 serial->base = rt_ioremap_early((void *)serial->base, serial->size);
99 }
100
101 if (serial->base && con)
102 {
103 con->console_putc = (typeof(con->console_putc))&serial8250_early_putc;
104 con->console_kick = serial8250_early_kick;
105 con->data = &serial->parent;
106
107 if (!serial->parent.config.baud_rate)
108 {
109 /* assume the device was initialized, only mask interrupts */
110 rt_uint32_t ier = serial8250_early_in(serial, UART_IER);
111 serial8250_early_out(serial, UART_IER, ier & UART_IER_UUE);
112 }
113 else
114 {
115 init_serial(serial);
116 }
117 }
118 else
119 {
120 ret = -RT_ERROR;
121 }
122
123 return ret;
124 }
125
common_init(struct serial8250 * serial,struct rt_fdt_earlycon * con)126 static void common_init(struct serial8250 *serial, struct rt_fdt_earlycon *con)
127 {
128 serial->base = (void *)con->mmio;
129 serial->size = con->size;
130 serial->iotype = PORT_MMIO32;
131 }
132
common_early_setup(struct rt_fdt_earlycon * con,const char * options)133 static rt_err_t common_early_setup(struct rt_fdt_earlycon *con, const char *options)
134 {
135 struct serial8250 *serial = &early_serial8250;
136
137 common_init(serial, con);
138 serial->regshift = 2;
139 fdt_getprop_u32(con->fdt, con->nodeoffset, "reg-shift", &serial->regshift, RT_NULL);
140
141 return serial8250_early_fdt_setup(serial, con, options);
142 }
143 RT_FDT_EARLYCON_EXPORT(bcm2835aux, "uart8250", "brcm,bcm2835-aux-uart", common_early_setup);
144 RT_FDT_EARLYCON_EXPORT(tegra20, "uart8250", "nvidia,tegra20-uart", common_early_setup);
145 RT_FDT_EARLYCON_EXPORT(dw8250, "uart8250", "snps,dw-apb-uart", common_early_setup);
146 RT_FDT_EARLYCON_EXPORT(ns16550a, "uart8250", "ns16550a", common_early_setup);
147 RT_FDT_EARLYCON_EXPORT(ns16550, "uart8250", "ns16550", common_early_setup);
148
149 #ifdef RT_USING_8250_OMAP
omap8250_early_setup(struct rt_fdt_earlycon * con,const char * options)150 static rt_err_t omap8250_early_setup(struct rt_fdt_earlycon *con, const char *options)
151 {
152 struct serial8250 *serial = &early_serial8250;
153
154 common_init(serial, con);
155 serial->regshift = 2;
156
157 return serial8250_early_fdt_setup(serial, con, options);
158 }
159 RT_FDT_EARLYCON_EXPORT(omap8250, "uart8250", "ti,omap2-uart", omap8250_early_setup);
160 RT_FDT_EARLYCON_EXPORT(omap8250, "uart8250", "ti,omap3-uart", omap8250_early_setup);
161 RT_FDT_EARLYCON_EXPORT(omap8250, "uart8250", "ti,omap4-uart", omap8250_early_setup);
162 #endif /* RT_USING_8250_OMAP */
163