xref: /freebsd/sys/arm/ti/clk/ti_divider_clock.c (revision bdd1243df58e60e85101c09001d9812a789b6bc4)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2020 Oskar Holmlund <oskar.holmlund@ohdata.se>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
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,
20  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
21  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
22  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * $FreeBSD$
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/conf.h>
35 #include <sys/bus.h>
36 #include <sys/kernel.h>
37 #include <sys/module.h>
38 #include <sys/systm.h>
39 #include <sys/libkern.h>
40 
41 #include <machine/bus.h>
42 #include <dev/fdt/simplebus.h>
43 
44 #include <dev/extres/clk/clk_div.h>
45 #include <dev/ofw/ofw_bus.h>
46 #include <dev/ofw/ofw_bus_subr.h>
47 
48 #include "clock_common.h"
49 
50 #if 0
51 #define DPRINTF(dev, msg...) device_printf(dev, msg)
52 #else
53 #define DPRINTF(dev, msg...)
54 #endif
55 
56 /*
57  * Devicetree description
58  * Documentation/devicetree/bindings/clock/ti/divider.txt
59  */
60 
61 struct ti_divider_softc {
62 	device_t		sc_dev;
63 	bool			attach_done;
64 	struct clk_div_def	div_def;
65 
66 	struct clock_cell_info	clock_cell;
67 	struct clkdom		*clkdom;
68 };
69 
70 static int ti_divider_probe(device_t dev);
71 static int ti_divider_attach(device_t dev);
72 static int ti_divider_detach(device_t dev);
73 
74 #define TI_DIVIDER_CLOCK		2
75 #define TI_COMPOSITE_DIVIDER_CLOCK	1
76 #define TI_DIVIDER_END			0
77 
78 static struct ofw_compat_data compat_data[] = {
79 	{ "ti,divider-clock",		TI_DIVIDER_CLOCK },
80 	{ "ti,composite-divider-clock",	TI_COMPOSITE_DIVIDER_CLOCK },
81 	{ NULL,				TI_DIVIDER_END }
82 };
83 
84 static int
85 register_clk(struct ti_divider_softc *sc) {
86 	int err;
87 
88 	sc->clkdom = clkdom_create(sc->sc_dev);
89 	if (sc->clkdom == NULL) {
90 		DPRINTF(sc->sc_dev, "Failed to create clkdom\n");
91 		return (ENXIO);
92 	}
93 
94 	err = clknode_div_register(sc->clkdom, &sc->div_def);
95 	if (err) {
96 		DPRINTF(sc->sc_dev, "clknode_div_register failed %x\n", err);
97 		return (ENXIO);
98 	}
99 
100 	err = clkdom_finit(sc->clkdom);
101 	if (err) {
102 		DPRINTF(sc->sc_dev, "Clk domain finit fails %x.\n", err);
103 		return (ENXIO);
104 	}
105 
106 	return (0);
107 }
108 
109 static int
110 ti_divider_probe(device_t dev)
111 {
112 	if (!ofw_bus_status_okay(dev))
113 		return (ENXIO);
114 
115 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
116 		return (ENXIO);
117 
118 	device_set_desc(dev, "TI Divider Clock");
119 
120 	return (BUS_PROBE_DEFAULT);
121 }
122 
123 static int
124 ti_divider_attach(device_t dev)
125 {
126 	struct ti_divider_softc *sc;
127 	phandle_t	node;
128 	int		err;
129 	cell_t		value;
130 	uint32_t	ti_max_div;
131 
132 	sc = device_get_softc(dev);
133 	sc->sc_dev = dev;
134 	node = ofw_bus_get_node(dev);
135 
136 	/* Grab the content of reg properties */
137 	OF_getencprop(node, "reg", &value, sizeof(value));
138 	sc->div_def.offset = value;
139 
140 	if (OF_hasprop(node, "ti,bit-shift")) {
141 		OF_getencprop(node, "ti,bit-shift", &value, sizeof(value));
142 		sc->div_def.i_shift = value;
143 	}
144 
145 	if (OF_hasprop(node, "ti,index-starts-at-one")) {
146 		sc->div_def.div_flags = CLK_DIV_ZERO_BASED;
147 	}
148 
149 	if (OF_hasprop(node, "ti,index-power-of-two")) {
150 		/* FIXME: later */
151 		device_printf(sc->sc_dev, "ti,index-power-of-two - Not implemented\n");
152 		/* remember to update i_width a few lines below */
153 	}
154 	if (OF_hasprop(node, "ti,max-div")) {
155 		OF_getencprop(node, "ti,max-div", &value, sizeof(value));
156 		ti_max_div = value;
157 	}
158 
159 	if (OF_hasprop(node, "clock-output-names"))
160 		device_printf(sc->sc_dev, "clock-output-names\n");
161 	if (OF_hasprop(node, "ti,dividers"))
162 		device_printf(sc->sc_dev, "ti,dividers\n");
163 	if (OF_hasprop(node, "ti,min-div"))
164 		device_printf(sc->sc_dev, "ti,min-div - Not implemented\n");
165 
166 	if (OF_hasprop(node, "ti,autoidle-shift"))
167 		device_printf(sc->sc_dev, "ti,autoidle-shift - Not implemented\n");
168 	if (OF_hasprop(node, "ti,set-rate-parent"))
169 		device_printf(sc->sc_dev, "ti,set-rate-parent - Not implemented\n");
170 	if (OF_hasprop(node, "ti,latch-bit"))
171 		device_printf(sc->sc_dev, "ti,latch-bit - Not implemented\n");
172 
173 	/* Figure out the width from ti_max_div */
174 	if (sc->div_def.div_flags)
175 		sc->div_def.i_width = fls(ti_max_div-1);
176 	else
177 		sc->div_def.i_width = fls(ti_max_div);
178 
179 	DPRINTF(sc->sc_dev, "div_def.i_width %x\n", sc->div_def.i_width);
180 
181 	read_clock_cells(sc->sc_dev, &sc->clock_cell);
182 
183 	create_clkdef(sc->sc_dev, &sc->clock_cell, &sc->div_def.clkdef);
184 
185 	err = find_parent_clock_names(sc->sc_dev, &sc->clock_cell, &sc->div_def.clkdef);
186 
187 	if (err) {
188 		/* free_clkdef will be called in ti_divider_new_pass */
189 		DPRINTF(sc->sc_dev, "find_parent_clock_names failed\n");
190 		return (bus_generic_attach(sc->sc_dev));
191 	}
192 
193 	err = register_clk(sc);
194 
195 	if (err) {
196 		/* free_clkdef will be called in ti_divider_new_pass */
197 		DPRINTF(sc->sc_dev, "register_clk failed\n");
198 		return (bus_generic_attach(sc->sc_dev));
199 	}
200 
201 	sc->attach_done = true;
202 
203 	free_clkdef(&sc->div_def.clkdef);
204 
205 	return (bus_generic_attach(sc->sc_dev));
206 }
207 
208 static int
209 ti_divider_detach(device_t dev)
210 {
211 	return (EBUSY);
212 }
213 
214 static void
215 ti_divider_new_pass(device_t dev)
216 {
217 	struct ti_divider_softc *sc;
218 	int err;
219 
220 	sc = device_get_softc(dev);
221 
222 	if (sc->attach_done) {
223 		return;
224 	}
225 
226 	err = find_parent_clock_names(sc->sc_dev, &sc->clock_cell, &sc->div_def.clkdef);
227 	if (err) {
228 		/* free_clkdef will be called in a later call to ti_divider_new_pass */
229 		DPRINTF(sc->sc_dev, "new_pass find_parent_clock_names failed\n");
230 		return;
231 	}
232 
233 	err = register_clk(sc);
234 	if (err) {
235 		/* free_clkdef will be called in a later call to ti_divider_new_pass */
236 		DPRINTF(sc->sc_dev, "new_pass register_clk failed\n");
237 		return;
238 	}
239 
240 	sc->attach_done = true;
241 
242 	free_clkdef(&sc->div_def.clkdef);
243 }
244 
245 static device_method_t ti_divider_methods[] = {
246 	/* Device interface */
247 	DEVMETHOD(device_probe,		ti_divider_probe),
248 	DEVMETHOD(device_attach,	ti_divider_attach),
249 	DEVMETHOD(device_detach,	ti_divider_detach),
250 
251 	/* Bus interface */
252 	DEVMETHOD(bus_new_pass,		ti_divider_new_pass),
253 
254 	DEVMETHOD_END
255 };
256 
257 DEFINE_CLASS_0(ti_divider, ti_divider_driver, ti_divider_methods,
258 	sizeof(struct ti_divider_softc));
259 
260 EARLY_DRIVER_MODULE(ti_divider, simplebus, ti_divider_driver, 0, 0,
261     BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
262 MODULE_VERSION(ti_divider, 1);
263