xref: /openbsd/sys/dev/fdt/com_fdt.c (revision 4cfece93)
1 /* $OpenBSD: com_fdt.c,v 1.4 2020/03/23 21:40:01 uaa Exp $ */
2 /*
3  * Copyright (c) 2016 Patrick Wildt <patrick@blueri.se>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #include <sys/param.h>
19 #include <sys/systm.h>
20 #include <sys/device.h>
21 #include <sys/tty.h>
22 
23 #include <machine/intr.h>
24 #include <machine/bus.h>
25 #include <machine/fdt.h>
26 
27 #include <dev/ic/comreg.h>
28 #include <dev/ic/comvar.h>
29 #include <dev/cons.h>
30 
31 #include <dev/ofw/fdt.h>
32 #include <dev/ofw/openfirm.h>
33 #include <dev/ofw/ofw_clock.h>
34 #include <dev/ofw/ofw_pinctrl.h>
35 
36 #define com_usr 31	/* Synopsys DesignWare UART */
37 
38 int	com_fdt_match(struct device *, void *, void *);
39 void	com_fdt_attach(struct device *, struct device *, void *);
40 int	com_fdt_intr_designware(void *);
41 
42 struct cfattach com_fdt_ca = {
43 	sizeof (struct com_softc), com_fdt_match, com_fdt_attach
44 };
45 
46 struct consdev com_fdt_cons = {
47 	NULL, NULL, comcngetc, comcnputc, comcnpollc, NULL,
48 	NODEV, CN_LOWPRI
49 };
50 
51 void
52 com_fdt_init_cons(void)
53 {
54 	struct fdt_reg reg;
55 	void *node;
56 
57 	if ((node = fdt_find_cons("brcm,bcm2835-aux-uart")) == NULL &&
58 	    (node = fdt_find_cons("snps,dw-apb-uart")) == NULL &&
59 	    (node = fdt_find_cons("marvell,armada-38x-uart")) == NULL &&
60 	    (node = fdt_find_cons("ti,omap3-uart")) == NULL &&
61 	    (node = fdt_find_cons("ti,omap4-uart")) == NULL)
62 			return;
63 	if (fdt_get_reg(node, 0, &reg))
64 		return;
65 
66 	/*
67 	 * Figuring out the clock frequency is rather complicated as
68 	 * on many SoCs this requires traversing a fair amount of the
69 	 * clock tree.  Instead we rely on the firmware to set up the
70 	 * console for us and bypass the cominit() call that
71 	 * comcnattach() does by doing the minimal setup here.
72 	 */
73 
74 	comcons_reg_width = OF_getpropint(stdout_node, "reg-io-width", 4);
75 	comcons_reg_shift = OF_getpropint(stdout_node, "reg-shift", 2);
76 
77 	comconsiot = fdt_cons_bs_tag;
78 	if (bus_space_map(comconsiot, reg.addr, reg.size, 0, &comconsioh))
79 		return;
80 
81 	cn_tab = &com_fdt_cons;
82 }
83 
84 int
85 com_fdt_match(struct device *parent, void *match, void *aux)
86 {
87 	struct fdt_attach_args *faa = aux;
88 
89 	return (OF_is_compatible(faa->fa_node, "brcm,bcm2835-aux-uart") ||
90 	    OF_is_compatible(faa->fa_node, "snps,dw-apb-uart") ||
91 	    OF_is_compatible(faa->fa_node, "marvell,armada-38x-uart") ||
92 	    OF_is_compatible(faa->fa_node, "ti,omap3-uart") ||
93 	    OF_is_compatible(faa->fa_node, "ti,omap4-uart"));
94 }
95 
96 void
97 com_fdt_attach(struct device *parent, struct device *self, void *aux)
98 {
99 	struct com_softc *sc = (struct com_softc *)self;
100 	struct fdt_attach_args *faa = aux;
101 	int (*intr)(void *) = comintr;
102 	uint32_t freq;
103 
104 	if (faa->fa_nreg < 1)
105 		return;
106 
107 	clock_enable(faa->fa_node, NULL);
108 	reset_deassert_all(faa->fa_node);
109 
110 	/*
111 	 * Determine the clock frequency after enabling the clock.
112 	 * This gives the clock code a chance to configure the
113 	 * appropriate frequency for us.
114 	 */
115 	freq = OF_getpropint(faa->fa_node, "clock-frequency", 0);
116 	if (freq == 0)
117 		freq = clock_get_frequency(faa->fa_node, NULL);
118 
119 	sc->sc_iot = faa->fa_iot;
120 	sc->sc_iobase = faa->fa_reg[0].addr;
121 	sc->sc_uarttype = COM_UART_16550;
122 	sc->sc_frequency = freq ? freq : COM_FREQ;
123 
124 	sc->sc_reg_width = OF_getpropint(faa->fa_node, "reg-io-width", 4);
125 	sc->sc_reg_shift = OF_getpropint(faa->fa_node, "reg-shift", 2);
126 
127 	if (OF_is_compatible(faa->fa_node, "snps,dw-apb-uart") ||
128 	    OF_is_compatible(faa->fa_node, "marvell,armada-38x-uart"))
129 		intr = com_fdt_intr_designware;
130 
131 	if (OF_is_compatible(faa->fa_node, "ti,omap3-uart") ||
132 	    OF_is_compatible(faa->fa_node, "ti,omap4-uart"))
133 		sc->sc_uarttype = COM_UART_TI16750;
134 
135 	if (stdout_node == faa->fa_node) {
136 		SET(sc->sc_hwflags, COM_HW_CONSOLE);
137 		SET(sc->sc_swflags, COM_SW_SOFTCAR);
138 		comconsfreq = sc->sc_frequency;
139 		comconsrate = stdout_speed ? stdout_speed : B115200;
140 	}
141 
142 	if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr,
143 	    faa->fa_reg[0].size, 0, &sc->sc_ioh)) {
144 		printf("%s: bus_space_map failed\n", __func__);
145 		return;
146 	}
147 
148 	pinctrl_byname(faa->fa_node, "default");
149 
150 	com_attach_subr(sc);
151 
152 	fdt_intr_establish(faa->fa_node, IPL_TTY, intr,
153 	    sc, sc->sc_dev.dv_xname);
154 }
155 
156 int
157 com_fdt_intr_designware(void *cookie)
158 {
159 	struct com_softc *sc = cookie;
160 
161 	com_read_reg(sc, com_usr);
162 
163 	return comintr(sc);
164 }
165