xref: /freebsd/sys/dev/uart/uart_dev_ti8250.c (revision a0ee8cc636cd5c2374ec44ca71226564ea0bca95)
1 /*-
2  * Copyright (c) 2013 Ian Lepore
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include "opt_platform.h"
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/conf.h>
36 #include <sys/kernel.h>
37 #include <sys/sysctl.h>
38 #include <machine/bus.h>
39 
40 #include <arm/ti/ti_prcm.h>
41 #include <arm/ti/ti_hwmods.h>
42 
43 #include <dev/fdt/fdt_common.h>
44 #include <dev/ofw/ofw_bus.h>
45 #include <dev/ofw/ofw_bus_subr.h>
46 
47 #include <dev/uart/uart.h>
48 #include <dev/uart/uart_cpu.h>
49 #include <dev/uart/uart_cpu_fdt.h>
50 #include <dev/uart/uart_bus.h>
51 #include <dev/uart/uart_dev_ns8250.h>
52 
53 #include "uart_if.h"
54 
55 /*
56  * High-level UART interface.
57  */
58 struct ti8250_softc {
59 	struct ns8250_softc ns8250_base;
60 	/*uint32_t	mystuff;*/
61 };
62 
63 #define	MDR1_REG		8
64 #define	  MDR1_MODE_UART	0
65 #define	  MDR1_MODE_DISABLE	7
66 #define	SYSCC_REG		15
67 #define	  SYSCC_SOFTRESET	(1 << 1)
68 #define	SYSS_REG		16
69 #define	  SYSS_STATUS_RESETDONE	(1 << 0)
70 
71 static int
72 ti8250_bus_probe(struct uart_softc *sc)
73 {
74 	int status;
75 	clk_ident_t clkid;
76 
77 	/* Enable clocks for this device.  We can't continue if that fails.  */
78 	clkid = ti_hwmods_get_clock(sc->sc_dev);
79 	if (clkid == INVALID_CLK_IDENT) {
80 		device_printf(sc->sc_dev,
81 		    "failed to get clock based on hwmods\n");
82 		clkid = UART1_CLK + device_get_unit(sc->sc_dev);
83 	}
84 	if ((status = ti_prcm_clk_enable(clkid)) != 0)
85 		return (status);
86 
87 	/*
88 	 * Set the hardware to disabled mode, do a full device reset, then set
89 	 * it to uart mode.  Most devices will be reset-and-disabled already,
90 	 * but you never know what a bootloader might have done.
91 	 */
92 	uart_setreg(&sc->sc_bas, MDR1_REG, MDR1_MODE_DISABLE);
93 	uart_setreg(&sc->sc_bas, SYSCC_REG, SYSCC_SOFTRESET);
94 	while (uart_getreg(&sc->sc_bas, SYSS_REG) & SYSS_STATUS_RESETDONE)
95 		continue;
96 	uart_setreg(&sc->sc_bas, MDR1_REG, MDR1_MODE_UART);
97 
98 	status = ns8250_bus_probe(sc);
99 	if (status == 0)
100 		device_set_desc(sc->sc_dev, "TI UART (16550 compatible)");
101 
102 	return (status);
103 }
104 
105 static kobj_method_t ti8250_methods[] = {
106 	KOBJMETHOD(uart_probe,		ti8250_bus_probe),
107 
108 	KOBJMETHOD(uart_attach,		ns8250_bus_attach),
109 	KOBJMETHOD(uart_detach,		ns8250_bus_detach),
110 	KOBJMETHOD(uart_flush,		ns8250_bus_flush),
111 	KOBJMETHOD(uart_getsig,		ns8250_bus_getsig),
112 	KOBJMETHOD(uart_ioctl,		ns8250_bus_ioctl),
113 	KOBJMETHOD(uart_ipend,		ns8250_bus_ipend),
114 	KOBJMETHOD(uart_param,		ns8250_bus_param),
115 	KOBJMETHOD(uart_receive,	ns8250_bus_receive),
116 	KOBJMETHOD(uart_setsig,		ns8250_bus_setsig),
117 	KOBJMETHOD(uart_transmit,	ns8250_bus_transmit),
118 	KOBJMETHOD_END
119 };
120 
121 static struct uart_class uart_ti8250_class = {
122 	"ti8250",
123 	ti8250_methods,
124 	sizeof(struct ti8250_softc),
125 	.uc_ops = &uart_ns8250_ops,
126 	.uc_range = 0x88,
127 	.uc_rclk = 48000000,
128 	.uc_rshift = 2
129 };
130 static struct ofw_compat_data compat_data[] = {
131 	{"ti,ns16550",		(uintptr_t)&uart_ti8250_class},
132 	{"ti,omap3-uart",	(uintptr_t)&uart_ti8250_class},
133 	{"ti,omap4-uart",	(uintptr_t)&uart_ti8250_class},
134 	{NULL,			(uintptr_t)NULL},
135 };
136 UART_FDT_CLASS_AND_DEVICE(compat_data);
137