xref: /openbmc/u-boot/drivers/serial/serial_omap.c (revision 93f33627)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Texas Instruments' OMAP serial driver
4  *
5  * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
6  *	Lokesh Vutla <lokeshvutla@ti.com>
7  */
8 
9 #include <common.h>
10 #include <debug_uart.h>
11 #include <dm.h>
12 #include <dt-structs.h>
13 #include <ns16550.h>
14 #include <serial.h>
15 #include <clk.h>
16 
17 #ifndef CONFIG_SYS_NS16550_CLK
18 #define CONFIG_SYS_NS16550_CLK  0
19 #endif
20 
21 #ifdef CONFIG_DEBUG_UART_OMAP
22 
23 #include <debug_uart.h>
24 
25 static inline void _debug_uart_init(void)
26 {
27 	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
28 	int baud_divisor;
29 
30 	baud_divisor = ns16550_calc_divisor(com_port, CONFIG_DEBUG_UART_CLOCK,
31 					    CONFIG_BAUDRATE);
32 	serial_dout(&com_port->ier, CONFIG_SYS_NS16550_IER);
33 	serial_dout(&com_port->mdr1, 0x7);
34 	serial_dout(&com_port->mcr, UART_MCRVAL);
35 	serial_dout(&com_port->fcr, UART_FCR_DEFVAL);
36 
37 	serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL);
38 	serial_dout(&com_port->dll, baud_divisor & 0xff);
39 	serial_dout(&com_port->dlm, (baud_divisor >> 8) & 0xff);
40 	serial_dout(&com_port->lcr, UART_LCRVAL);
41 	serial_dout(&com_port->mdr1, 0x0);
42 }
43 
44 static inline void _debug_uart_putc(int ch)
45 {
46 	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
47 
48 	while (!(serial_din(&com_port->lsr) & UART_LSR_THRE))
49 		;
50 	serial_dout(&com_port->thr, ch);
51 }
52 
53 DEBUG_UART_FUNCS
54 
55 #endif
56 
57 #if CONFIG_IS_ENABLED(DM_SERIAL)
58 
59 #if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
60 static int omap_serial_ofdata_to_platdata(struct udevice *dev)
61 {
62 	struct ns16550_platdata *plat = dev->platdata;
63 	fdt_addr_t addr;
64 	struct clk clk;
65 	int err;
66 
67 	/* try Processor Local Bus device first */
68 	addr = dev_read_addr(dev);
69 	if (addr == FDT_ADDR_T_NONE)
70 		return -EINVAL;
71 
72 	plat->base = (unsigned long)map_physmem(addr, 0, MAP_NOCACHE);
73 
74 	plat->reg_offset = dev_read_u32_default(dev, "reg-offset", 0);
75 	plat->reg_shift = 2;
76 
77 	err = clk_get_by_index(dev, 0, &clk);
78 	if (!err) {
79 		err = clk_get_rate(&clk);
80 		if (!IS_ERR_VALUE(err))
81 			plat->clock = err;
82 	} else if (err != -ENOENT && err != -ENODEV && err != -ENOSYS) {
83 		debug("omap serial failed to get clock\n");
84 		return err;
85 	}
86 
87 	if (!plat->clock)
88 		plat->clock = dev_read_u32_default(dev, "clock-frequency",
89 						   CONFIG_SYS_NS16550_CLK);
90 	if (!plat->clock) {
91 		debug("omap serial clock not defined\n");
92 		return -EINVAL;
93 	}
94 
95 	plat->fcr = UART_FCR_DEFVAL;
96 
97 	return 0;
98 }
99 
100 static const struct udevice_id omap_serial_ids[] = {
101 	{ .compatible = "ti,omap2-uart", },
102 	{ .compatible = "ti,omap3-uart", },
103 	{ .compatible = "ti,omap4-uart", },
104 	{ .compatible = "ti,am3352-uart", },
105 	{ .compatible = "ti,am4372-uart", },
106 	{ .compatible = "ti,dra742-uart", },
107 	{}
108 };
109 #endif /* OF_CONTROL && !OF_PLATDATA */
110 
111 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
112 U_BOOT_DRIVER(omap_serial) = {
113 	.name	= "omap_serial",
114 	.id	= UCLASS_SERIAL,
115 #if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
116 	.of_match = omap_serial_ids,
117 	.ofdata_to_platdata = omap_serial_ofdata_to_platdata,
118 	.platdata_auto_alloc_size = sizeof(struct ns16550_platdata),
119 #endif
120 	.priv_auto_alloc_size = sizeof(struct NS16550),
121 	.probe = ns16550_serial_probe,
122 	.ops	= &ns16550_serial_ops,
123 	.flags	= DM_FLAG_PRE_RELOC,
124 };
125 #endif
126 #endif /* DM_SERIAL */
127