xref: /freebsd/sys/dev/uart/uart_dev_ti8250.c (revision 42249ef2)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2013 Ian Lepore
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include "opt_platform.h"
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/bus.h>
37 #include <sys/conf.h>
38 #include <sys/kernel.h>
39 #include <sys/sysctl.h>
40 #include <machine/bus.h>
41 
42 #include <arm/ti/ti_prcm.h>
43 #include <arm/ti/ti_hwmods.h>
44 
45 #include <dev/fdt/fdt_common.h>
46 #include <dev/ofw/ofw_bus.h>
47 #include <dev/ofw/ofw_bus_subr.h>
48 
49 #include <dev/uart/uart.h>
50 #include <dev/uart/uart_cpu.h>
51 #include <dev/uart/uart_cpu_fdt.h>
52 #include <dev/uart/uart_bus.h>
53 #include <dev/uart/uart_dev_ns8250.h>
54 
55 #include "uart_if.h"
56 
57 /*
58  * High-level UART interface.
59  */
60 struct ti8250_softc {
61 	struct ns8250_softc ns8250_base;
62 	/*uint32_t	mystuff;*/
63 };
64 
65 #define	MDR1_REG		8
66 #define	  MDR1_MODE_UART	0
67 #define	  MDR1_MODE_DISABLE	7
68 #define	SYSCC_REG		15
69 #define	  SYSCC_SOFTRESET	(1 << 1)
70 #define	SYSS_REG		16
71 #define	  SYSS_STATUS_RESETDONE	(1 << 0)
72 
73 static int
74 ti8250_bus_probe(struct uart_softc *sc)
75 {
76 	int status;
77 	clk_ident_t clkid;
78 
79 	/* Enable clocks for this device.  We can't continue if that fails.  */
80 	clkid = ti_hwmods_get_clock(sc->sc_dev);
81 	if (clkid == INVALID_CLK_IDENT) {
82 		device_printf(sc->sc_dev,
83 		    "failed to get clock based on hwmods\n");
84 		clkid = UART1_CLK + device_get_unit(sc->sc_dev);
85 	}
86 	if ((status = ti_prcm_clk_enable(clkid)) != 0)
87 		return (status);
88 
89 	/*
90 	 * Set the hardware to disabled mode, do a full device reset, then set
91 	 * it to uart mode.  Most devices will be reset-and-disabled already,
92 	 * but you never know what a bootloader might have done.
93 	 */
94 	uart_setreg(&sc->sc_bas, MDR1_REG, MDR1_MODE_DISABLE);
95 	uart_setreg(&sc->sc_bas, SYSCC_REG, SYSCC_SOFTRESET);
96 	while (uart_getreg(&sc->sc_bas, SYSS_REG) & SYSS_STATUS_RESETDONE)
97 		continue;
98 	uart_setreg(&sc->sc_bas, MDR1_REG, MDR1_MODE_UART);
99 
100 	status = ns8250_bus_probe(sc);
101 	if (status == 0)
102 		device_set_desc(sc->sc_dev, "TI UART (16550 compatible)");
103 
104 	return (status);
105 }
106 
107 static kobj_method_t ti8250_methods[] = {
108 	KOBJMETHOD(uart_probe,		ti8250_bus_probe),
109 
110 	KOBJMETHOD(uart_attach,		ns8250_bus_attach),
111 	KOBJMETHOD(uart_detach,		ns8250_bus_detach),
112 	KOBJMETHOD(uart_flush,		ns8250_bus_flush),
113 	KOBJMETHOD(uart_getsig,		ns8250_bus_getsig),
114 	KOBJMETHOD(uart_ioctl,		ns8250_bus_ioctl),
115 	KOBJMETHOD(uart_ipend,		ns8250_bus_ipend),
116 	KOBJMETHOD(uart_param,		ns8250_bus_param),
117 	KOBJMETHOD(uart_receive,	ns8250_bus_receive),
118 	KOBJMETHOD(uart_setsig,		ns8250_bus_setsig),
119 	KOBJMETHOD(uart_transmit,	ns8250_bus_transmit),
120 	KOBJMETHOD_END
121 };
122 
123 static struct uart_class uart_ti8250_class = {
124 	"ti8250",
125 	ti8250_methods,
126 	sizeof(struct ti8250_softc),
127 	.uc_ops = &uart_ns8250_ops,
128 	.uc_range = 0x88,
129 	.uc_rclk = 48000000,
130 	.uc_rshift = 2
131 };
132 static struct ofw_compat_data compat_data[] = {
133 	{"ti,ns16550",		(uintptr_t)&uart_ti8250_class},
134 	{"ti,omap3-uart",	(uintptr_t)&uart_ti8250_class},
135 	{"ti,omap4-uart",	(uintptr_t)&uart_ti8250_class},
136 	{NULL,			(uintptr_t)NULL},
137 };
138 UART_FDT_CLASS_AND_DEVICE(compat_data);
139