1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2019 Ian Lepore <ian@freebsd.org>
5 * Copyright (c) 2020-2021 Andriy Gapon
6 * Copyright (c) 2022-2024 Bjoern A. Zeeb
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include <sys/cdefs.h>
31 #include "opt_platform.h"
32
33 #include <sys/param.h>
34 #include <sys/bus.h>
35 #include <sys/kernel.h>
36 #include <sys/module.h>
37 #include <sys/systm.h>
38
39 #ifdef FDT
40 #include <dev/ofw/ofw_bus.h>
41 #include <dev/ofw/ofw_bus_subr.h>
42 #include <dev/ofw/openfirm.h>
43 #endif
44
45 #include <dev/iicbus/iicbus.h>
46 #include <dev/iicbus/iiconf.h>
47 #include "iicbus_if.h"
48 #include "iicmux_if.h"
49 #include <dev/iicbus/mux/iicmux.h>
50
51 enum pca954x_type {
52 PCA954X_MUX,
53 PCA954X_SW,
54 };
55
56 struct pca954x_descr {
57 const char *partname;
58 const char *description;
59 enum pca954x_type type;
60 uint8_t numchannels;
61 uint8_t enable;
62 };
63
64 static struct pca954x_descr pca9540_descr = {
65 .partname = "pca9540",
66 .description = "PCA9540B I2C Mux",
67 .type = PCA954X_MUX,
68 .numchannels = 2,
69 .enable = 0x04,
70 };
71
72 static struct pca954x_descr pca9546_descr = {
73 .partname = "pca9546",
74 .description = "PCA9546 I2C Switch",
75 .type = PCA954X_SW,
76 .numchannels = 4,
77 };
78
79 static struct pca954x_descr pca9547_descr = {
80 .partname = "pca9547",
81 .description = "PCA9547 I2C Mux",
82 .type = PCA954X_MUX,
83 .numchannels = 8,
84 .enable = 0x08,
85 };
86
87 static struct pca954x_descr pca9548_descr = {
88 .partname = "pca9548",
89 .description = "PCA9548A I2C Switch",
90 .type = PCA954X_SW,
91 .numchannels = 8,
92 };
93
94 #ifdef FDT
95 static struct ofw_compat_data compat_data[] = {
96 { "nxp,pca9540", (uintptr_t)&pca9540_descr },
97 { "nxp,pca9546", (uintptr_t)&pca9546_descr },
98 { "nxp,pca9547", (uintptr_t)&pca9547_descr },
99 { "nxp,pca9548", (uintptr_t)&pca9548_descr },
100 { NULL, 0 },
101 };
102 #else
103 static struct pca954x_descr *part_descrs[] = {
104 &pca9540_descr,
105 &pca9546_descr,
106 &pca9547_descr,
107 &pca9548_descr,
108 };
109 #endif
110
111 struct pca954x_softc {
112 struct iicmux_softc mux;
113 const struct pca954x_descr *descr;
114 uint8_t addr;
115 bool idle_disconnect;
116 };
117
118 static int
pca954x_bus_select(device_t dev,int busidx,struct iic_reqbus_data * rd)119 pca954x_bus_select(device_t dev, int busidx, struct iic_reqbus_data *rd)
120 {
121 struct pca954x_softc *sc;
122 struct iic_msg msg;
123 int error;
124 uint8_t busbits;
125
126 sc = device_get_softc(dev);
127
128 /*
129 * The iicmux caller ensures busidx is between 0 and the number of buses
130 * we passed to iicmux_init_softc(), no need for validation here. If
131 * the fdt data has the idle_disconnect property we idle the bus by
132 * selecting no downstream buses, otherwise we just leave the current
133 * bus active.
134 */
135 if (busidx == IICMUX_SELECT_IDLE) {
136 if (sc->idle_disconnect)
137 busbits = 0;
138 else
139 return (0);
140 } else if (sc->descr->type == PCA954X_MUX) {
141 uint8_t en;
142
143 en = sc->descr->enable;
144 KASSERT(en > 0 && powerof2(en), ("%s: %s enable %#x "
145 "invalid\n", __func__, sc->descr->partname, en));
146 busbits = en | (busidx & (en - 1));
147 } else if (sc->descr->type == PCA954X_SW) {
148 busbits = 1u << busidx;
149 } else {
150 panic("%s: %s: unsupported type %d\n",
151 __func__, sc->descr->partname, sc->descr->type);
152 }
153
154 msg.slave = sc->addr;
155 msg.flags = IIC_M_WR;
156 msg.len = 1;
157 msg.buf = &busbits;
158 error = iicbus_transfer(dev, &msg, 1);
159 return (error);
160 }
161
162 static const struct pca954x_descr *
pca954x_find_chip(device_t dev)163 pca954x_find_chip(device_t dev)
164 {
165 #ifdef FDT
166 const struct ofw_compat_data *compat;
167
168 if (!ofw_bus_status_okay(dev))
169 return (NULL);
170
171 compat = ofw_bus_search_compatible(dev, compat_data);
172 if (compat == NULL)
173 return (NULL);
174 return ((const struct pca954x_descr *)compat->ocd_data);
175 #else
176 const char *type;
177 int i;
178
179 if (resource_string_value(device_get_name(dev), device_get_unit(dev),
180 "chip_type", &type) == 0) {
181 for (i = 0; i < nitems(part_descrs) - 1; ++i) {
182 if (strcasecmp(type, part_descrs[i]->partname) == 0)
183 return (part_descrs[i]);
184 }
185 }
186 return (NULL);
187 #endif
188 }
189
190 static int
pca954x_probe(device_t dev)191 pca954x_probe(device_t dev)
192 {
193 const struct pca954x_descr *descr;
194
195 descr = pca954x_find_chip(dev);
196 if (descr == NULL)
197 return (ENXIO);
198
199 device_set_desc(dev, descr->description);
200 return (BUS_PROBE_DEFAULT);
201 }
202
203 static int
pca954x_attach(device_t dev)204 pca954x_attach(device_t dev)
205 {
206 struct pca954x_softc *sc;
207 const struct pca954x_descr *descr;
208 int error;
209
210 sc = device_get_softc(dev);
211 sc->addr = iicbus_get_addr(dev);
212 sc->idle_disconnect = device_has_property(dev, "i2c-mux-idle-disconnect");
213
214 sc->descr = descr = pca954x_find_chip(dev);
215 error = iicmux_attach(dev, device_get_parent(dev), descr->numchannels);
216 if (error == 0)
217 bus_attach_children(dev);
218
219 return (error);
220 }
221
222 static int
pca954x_detach(device_t dev)223 pca954x_detach(device_t dev)
224 {
225 int error;
226
227 error = iicmux_detach(dev);
228 return (error);
229 }
230
231 static device_method_t pca954x_methods[] = {
232 /* device methods */
233 DEVMETHOD(device_probe, pca954x_probe),
234 DEVMETHOD(device_attach, pca954x_attach),
235 DEVMETHOD(device_detach, pca954x_detach),
236
237 /* iicmux methods */
238 DEVMETHOD(iicmux_bus_select, pca954x_bus_select),
239
240 DEVMETHOD_END
241 };
242
243 DEFINE_CLASS_1(pca954x, pca954x_driver, pca954x_methods,
244 sizeof(struct pca954x_softc), iicmux_driver);
245 DRIVER_MODULE(pca954x, iicbus, pca954x_driver, 0, 0);
246
247 #ifdef FDT
248 DRIVER_MODULE(ofw_iicbus, pca954x, ofw_iicbus_driver, 0, 0);
249 #else
250 DRIVER_MODULE(iicbus, pca954x, iicbus_driver, 0, 0);
251 #endif
252
253 MODULE_DEPEND(pca954x, iicmux, 1, 1, 1);
254 MODULE_DEPEND(pca954x, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
255 MODULE_VERSION(pca954x, 1);
256
257 #ifdef FDT
258 IICBUS_FDT_PNP_INFO(compat_data);
259 #endif
260