xref: /freebsd/sys/arm/ti/clk/ti_divider_clock.c (revision 6f1af0d7d2af54b339b5212434cd6d4fda628d80)
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 
28 #include <sys/cdefs.h>
29 #include <sys/param.h>
30 #include <sys/conf.h>
31 #include <sys/bus.h>
32 #include <sys/kernel.h>
33 #include <sys/module.h>
34 #include <sys/systm.h>
35 #include <sys/libkern.h>
36 
37 #include <machine/bus.h>
38 #include <dev/fdt/simplebus.h>
39 
40 #include <dev/extres/clk/clk_div.h>
41 #include <dev/ofw/ofw_bus.h>
42 #include <dev/ofw/ofw_bus_subr.h>
43 
44 #include "clock_common.h"
45 
46 #if 0
47 #define DPRINTF(dev, msg...) device_printf(dev, msg)
48 #else
49 #define DPRINTF(dev, msg...)
50 #endif
51 
52 /*
53  * Devicetree description
54  * Documentation/devicetree/bindings/clock/ti/divider.txt
55  */
56 
57 struct ti_divider_softc {
58 	device_t		sc_dev;
59 	bool			attach_done;
60 	struct clk_div_def	div_def;
61 
62 	struct clock_cell_info	clock_cell;
63 	struct clkdom		*clkdom;
64 };
65 
66 static int ti_divider_probe(device_t dev);
67 static int ti_divider_attach(device_t dev);
68 static int ti_divider_detach(device_t dev);
69 
70 #define TI_DIVIDER_CLOCK		2
71 #define TI_COMPOSITE_DIVIDER_CLOCK	1
72 #define TI_DIVIDER_END			0
73 
74 static struct ofw_compat_data compat_data[] = {
75 	{ "ti,divider-clock",		TI_DIVIDER_CLOCK },
76 	{ "ti,composite-divider-clock",	TI_COMPOSITE_DIVIDER_CLOCK },
77 	{ NULL,				TI_DIVIDER_END }
78 };
79 
80 static int
81 register_clk(struct ti_divider_softc *sc) {
82 	int err;
83 
84 	sc->clkdom = clkdom_create(sc->sc_dev);
85 	if (sc->clkdom == NULL) {
86 		DPRINTF(sc->sc_dev, "Failed to create clkdom\n");
87 		return (ENXIO);
88 	}
89 
90 	err = clknode_div_register(sc->clkdom, &sc->div_def);
91 	if (err) {
92 		DPRINTF(sc->sc_dev, "clknode_div_register failed %x\n", err);
93 		return (ENXIO);
94 	}
95 
96 	err = clkdom_finit(sc->clkdom);
97 	if (err) {
98 		DPRINTF(sc->sc_dev, "Clk domain finit fails %x.\n", err);
99 		return (ENXIO);
100 	}
101 
102 	return (0);
103 }
104 
105 static int
106 ti_divider_probe(device_t dev)
107 {
108 	if (!ofw_bus_status_okay(dev))
109 		return (ENXIO);
110 
111 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
112 		return (ENXIO);
113 
114 	device_set_desc(dev, "TI Divider Clock");
115 
116 	return (BUS_PROBE_DEFAULT);
117 }
118 
119 static int
120 ti_divider_attach(device_t dev)
121 {
122 	struct ti_divider_softc *sc;
123 	phandle_t	node;
124 	int		err;
125 	cell_t		value;
126 	uint32_t	ti_max_div;
127 
128 	sc = device_get_softc(dev);
129 	sc->sc_dev = dev;
130 	node = ofw_bus_get_node(dev);
131 
132 	/* Grab the content of reg properties */
133 	OF_getencprop(node, "reg", &value, sizeof(value));
134 	sc->div_def.offset = value;
135 
136 	if (OF_hasprop(node, "ti,bit-shift")) {
137 		OF_getencprop(node, "ti,bit-shift", &value, sizeof(value));
138 		sc->div_def.i_shift = value;
139 	}
140 
141 	if (OF_hasprop(node, "ti,index-starts-at-one")) {
142 		sc->div_def.div_flags = CLK_DIV_ZERO_BASED;
143 	}
144 
145 	if (OF_hasprop(node, "ti,index-power-of-two")) {
146 		/* FIXME: later */
147 		device_printf(sc->sc_dev, "ti,index-power-of-two - Not implemented\n");
148 		/* remember to update i_width a few lines below */
149 	}
150 	if (OF_hasprop(node, "ti,max-div")) {
151 		OF_getencprop(node, "ti,max-div", &value, sizeof(value));
152 		ti_max_div = value;
153 	}
154 
155 	if (OF_hasprop(node, "clock-output-names"))
156 		device_printf(sc->sc_dev, "clock-output-names\n");
157 	if (OF_hasprop(node, "ti,dividers"))
158 		device_printf(sc->sc_dev, "ti,dividers\n");
159 	if (OF_hasprop(node, "ti,min-div"))
160 		device_printf(sc->sc_dev, "ti,min-div - Not implemented\n");
161 
162 	if (OF_hasprop(node, "ti,autoidle-shift"))
163 		device_printf(sc->sc_dev, "ti,autoidle-shift - Not implemented\n");
164 	if (OF_hasprop(node, "ti,set-rate-parent"))
165 		device_printf(sc->sc_dev, "ti,set-rate-parent - Not implemented\n");
166 	if (OF_hasprop(node, "ti,latch-bit"))
167 		device_printf(sc->sc_dev, "ti,latch-bit - Not implemented\n");
168 
169 	/* Figure out the width from ti_max_div */
170 	if (sc->div_def.div_flags)
171 		sc->div_def.i_width = fls(ti_max_div-1);
172 	else
173 		sc->div_def.i_width = fls(ti_max_div);
174 
175 	DPRINTF(sc->sc_dev, "div_def.i_width %x\n", sc->div_def.i_width);
176 
177 	read_clock_cells(sc->sc_dev, &sc->clock_cell);
178 
179 	create_clkdef(sc->sc_dev, &sc->clock_cell, &sc->div_def.clkdef);
180 
181 	err = find_parent_clock_names(sc->sc_dev, &sc->clock_cell, &sc->div_def.clkdef);
182 
183 	if (err) {
184 		/* free_clkdef will be called in ti_divider_new_pass */
185 		DPRINTF(sc->sc_dev, "find_parent_clock_names failed\n");
186 		return (bus_generic_attach(sc->sc_dev));
187 	}
188 
189 	err = register_clk(sc);
190 
191 	if (err) {
192 		/* free_clkdef will be called in ti_divider_new_pass */
193 		DPRINTF(sc->sc_dev, "register_clk failed\n");
194 		return (bus_generic_attach(sc->sc_dev));
195 	}
196 
197 	sc->attach_done = true;
198 
199 	free_clkdef(&sc->div_def.clkdef);
200 
201 	return (bus_generic_attach(sc->sc_dev));
202 }
203 
204 static int
205 ti_divider_detach(device_t dev)
206 {
207 	return (EBUSY);
208 }
209 
210 static void
211 ti_divider_new_pass(device_t dev)
212 {
213 	struct ti_divider_softc *sc;
214 	int err;
215 
216 	sc = device_get_softc(dev);
217 
218 	if (sc->attach_done) {
219 		return;
220 	}
221 
222 	err = find_parent_clock_names(sc->sc_dev, &sc->clock_cell, &sc->div_def.clkdef);
223 	if (err) {
224 		/* free_clkdef will be called in a later call to ti_divider_new_pass */
225 		DPRINTF(sc->sc_dev, "new_pass find_parent_clock_names failed\n");
226 		return;
227 	}
228 
229 	err = register_clk(sc);
230 	if (err) {
231 		/* free_clkdef will be called in a later call to ti_divider_new_pass */
232 		DPRINTF(sc->sc_dev, "new_pass register_clk failed\n");
233 		return;
234 	}
235 
236 	sc->attach_done = true;
237 
238 	free_clkdef(&sc->div_def.clkdef);
239 }
240 
241 static device_method_t ti_divider_methods[] = {
242 	/* Device interface */
243 	DEVMETHOD(device_probe,		ti_divider_probe),
244 	DEVMETHOD(device_attach,	ti_divider_attach),
245 	DEVMETHOD(device_detach,	ti_divider_detach),
246 
247 	/* Bus interface */
248 	DEVMETHOD(bus_new_pass,		ti_divider_new_pass),
249 
250 	DEVMETHOD_END
251 };
252 
253 DEFINE_CLASS_0(ti_divider, ti_divider_driver, ti_divider_methods,
254 	sizeof(struct ti_divider_softc));
255 
256 EARLY_DRIVER_MODULE(ti_divider, simplebus, ti_divider_driver, 0, 0,
257     BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
258 MODULE_VERSION(ti_divider, 1);
259