xref: /freebsd/sys/arm/ti/clk/ti_divider_clock.c (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0)
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/param.h>
29 #include <sys/conf.h>
30 #include <sys/bus.h>
31 #include <sys/kernel.h>
32 #include <sys/module.h>
33 #include <sys/systm.h>
34 #include <sys/libkern.h>
35 
36 #include <machine/bus.h>
37 #include <dev/fdt/simplebus.h>
38 
39 #include <dev/clk/clk_div.h>
40 #include <dev/ofw/ofw_bus.h>
41 #include <dev/ofw/ofw_bus_subr.h>
42 
43 #include "clock_common.h"
44 
45 #if 0
46 #define DPRINTF(dev, msg...) device_printf(dev, msg)
47 #else
48 #define DPRINTF(dev, msg...)
49 #endif
50 
51 /*
52  * Devicetree description
53  * Documentation/devicetree/bindings/clock/ti/divider.txt
54  */
55 
56 struct ti_divider_softc {
57 	device_t		sc_dev;
58 	bool			attach_done;
59 	struct clk_div_def	div_def;
60 
61 	struct clock_cell_info	clock_cell;
62 	struct clkdom		*clkdom;
63 };
64 
65 static int ti_divider_probe(device_t dev);
66 static int ti_divider_attach(device_t dev);
67 static int ti_divider_detach(device_t dev);
68 
69 #define TI_DIVIDER_CLOCK		2
70 #define TI_COMPOSITE_DIVIDER_CLOCK	1
71 #define TI_DIVIDER_END			0
72 
73 static struct ofw_compat_data compat_data[] = {
74 	{ "ti,divider-clock",		TI_DIVIDER_CLOCK },
75 	{ "ti,composite-divider-clock",	TI_COMPOSITE_DIVIDER_CLOCK },
76 	{ NULL,				TI_DIVIDER_END }
77 };
78 
79 static int
80 register_clk(struct ti_divider_softc *sc) {
81 	int err;
82 
83 	sc->clkdom = clkdom_create(sc->sc_dev);
84 	if (sc->clkdom == NULL) {
85 		DPRINTF(sc->sc_dev, "Failed to create clkdom\n");
86 		return (ENXIO);
87 	}
88 
89 	err = clknode_div_register(sc->clkdom, &sc->div_def);
90 	if (err) {
91 		DPRINTF(sc->sc_dev, "clknode_div_register failed %x\n", err);
92 		return (ENXIO);
93 	}
94 
95 	err = clkdom_finit(sc->clkdom);
96 	if (err) {
97 		DPRINTF(sc->sc_dev, "Clk domain finit fails %x.\n", err);
98 		return (ENXIO);
99 	}
100 
101 	return (0);
102 }
103 
104 static int
105 ti_divider_probe(device_t dev)
106 {
107 	if (!ofw_bus_status_okay(dev))
108 		return (ENXIO);
109 
110 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
111 		return (ENXIO);
112 
113 	device_set_desc(dev, "TI Divider Clock");
114 
115 	return (BUS_PROBE_DEFAULT);
116 }
117 
118 static int
119 ti_divider_attach(device_t dev)
120 {
121 	struct ti_divider_softc *sc;
122 	phandle_t	node;
123 	int		err;
124 	cell_t		value;
125 	uint32_t	ti_max_div;
126 
127 	sc = device_get_softc(dev);
128 	sc->sc_dev = dev;
129 	node = ofw_bus_get_node(dev);
130 
131 	/* Grab the content of reg properties */
132 	OF_getencprop(node, "reg", &value, sizeof(value));
133 	sc->div_def.offset = value;
134 
135 	if (OF_hasprop(node, "ti,bit-shift")) {
136 		OF_getencprop(node, "ti,bit-shift", &value, sizeof(value));
137 		sc->div_def.i_shift = value;
138 	}
139 
140 	if (OF_hasprop(node, "ti,index-starts-at-one")) {
141 		sc->div_def.div_flags = CLK_DIV_ZERO_BASED;
142 	}
143 
144 	if (OF_hasprop(node, "ti,index-power-of-two")) {
145 		/* FIXME: later */
146 		device_printf(sc->sc_dev, "ti,index-power-of-two - Not implemented\n");
147 		/* remember to update i_width a few lines below */
148 	}
149 	if (OF_hasprop(node, "ti,max-div")) {
150 		OF_getencprop(node, "ti,max-div", &value, sizeof(value));
151 		ti_max_div = value;
152 	}
153 
154 	if (OF_hasprop(node, "clock-output-names"))
155 		device_printf(sc->sc_dev, "clock-output-names\n");
156 	if (OF_hasprop(node, "ti,dividers"))
157 		device_printf(sc->sc_dev, "ti,dividers\n");
158 	if (OF_hasprop(node, "ti,min-div"))
159 		device_printf(sc->sc_dev, "ti,min-div - Not implemented\n");
160 
161 	if (OF_hasprop(node, "ti,autoidle-shift"))
162 		device_printf(sc->sc_dev, "ti,autoidle-shift - Not implemented\n");
163 	if (OF_hasprop(node, "ti,set-rate-parent"))
164 		device_printf(sc->sc_dev, "ti,set-rate-parent - Not implemented\n");
165 	if (OF_hasprop(node, "ti,latch-bit"))
166 		device_printf(sc->sc_dev, "ti,latch-bit - Not implemented\n");
167 
168 	/* Figure out the width from ti_max_div */
169 	if (sc->div_def.div_flags)
170 		sc->div_def.i_width = fls(ti_max_div-1);
171 	else
172 		sc->div_def.i_width = fls(ti_max_div);
173 
174 	DPRINTF(sc->sc_dev, "div_def.i_width %x\n", sc->div_def.i_width);
175 
176 	read_clock_cells(sc->sc_dev, &sc->clock_cell);
177 
178 	create_clkdef(sc->sc_dev, &sc->clock_cell, &sc->div_def.clkdef);
179 
180 	err = find_parent_clock_names(sc->sc_dev, &sc->clock_cell, &sc->div_def.clkdef);
181 
182 	if (err) {
183 		/* free_clkdef will be called in ti_divider_new_pass */
184 		DPRINTF(sc->sc_dev, "find_parent_clock_names failed\n");
185 		return (bus_generic_attach(sc->sc_dev));
186 	}
187 
188 	err = register_clk(sc);
189 
190 	if (err) {
191 		/* free_clkdef will be called in ti_divider_new_pass */
192 		DPRINTF(sc->sc_dev, "register_clk failed\n");
193 		return (bus_generic_attach(sc->sc_dev));
194 	}
195 
196 	sc->attach_done = true;
197 
198 	free_clkdef(&sc->div_def.clkdef);
199 
200 	return (bus_generic_attach(sc->sc_dev));
201 }
202 
203 static int
204 ti_divider_detach(device_t dev)
205 {
206 	return (EBUSY);
207 }
208 
209 static void
210 ti_divider_new_pass(device_t dev)
211 {
212 	struct ti_divider_softc *sc;
213 	int err;
214 
215 	sc = device_get_softc(dev);
216 
217 	if (sc->attach_done) {
218 		return;
219 	}
220 
221 	err = find_parent_clock_names(sc->sc_dev, &sc->clock_cell, &sc->div_def.clkdef);
222 	if (err) {
223 		/* free_clkdef will be called in a later call to ti_divider_new_pass */
224 		DPRINTF(sc->sc_dev, "new_pass find_parent_clock_names failed\n");
225 		return;
226 	}
227 
228 	err = register_clk(sc);
229 	if (err) {
230 		/* free_clkdef will be called in a later call to ti_divider_new_pass */
231 		DPRINTF(sc->sc_dev, "new_pass register_clk failed\n");
232 		return;
233 	}
234 
235 	sc->attach_done = true;
236 
237 	free_clkdef(&sc->div_def.clkdef);
238 }
239 
240 static device_method_t ti_divider_methods[] = {
241 	/* Device interface */
242 	DEVMETHOD(device_probe,		ti_divider_probe),
243 	DEVMETHOD(device_attach,	ti_divider_attach),
244 	DEVMETHOD(device_detach,	ti_divider_detach),
245 
246 	/* Bus interface */
247 	DEVMETHOD(bus_new_pass,		ti_divider_new_pass),
248 
249 	DEVMETHOD_END
250 };
251 
252 DEFINE_CLASS_0(ti_divider, ti_divider_driver, ti_divider_methods,
253 	sizeof(struct ti_divider_softc));
254 
255 EARLY_DRIVER_MODULE(ti_divider, simplebus, ti_divider_driver, 0, 0,
256     BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
257 MODULE_VERSION(ti_divider, 1);
258