xref: /freebsd/sys/powerpc/powernv/opal_i2c.c (revision 95ee2897e98f5d444f26ed2334cc7c439f9c16c6)
1 /*-
2  * Copyright (c) 2017-2018 QCM Technologies.
3  * Copyright (c) 2017-2018 Semihalf.
4  * All rights reserved.
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 AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, 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 "opt_platform.h"
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/endian.h>
35 #include <sys/systm.h>
36 #include <sys/bus.h>
37 #include <sys/conf.h>
38 #include <sys/kernel.h>
39 #include <sys/lock.h>
40 #include <sys/mbuf.h>
41 #include <sys/malloc.h>
42 #include <sys/module.h>
43 #include <sys/mutex.h>
44 #include <sys/rman.h>
45 #include <machine/bus.h>
46 
47 #include <vm/vm.h>
48 #include <vm/pmap.h>
49 
50 #include <dev/iicbus/iiconf.h>
51 #include <dev/iicbus/iicbus.h>
52 #include "iicbus_if.h"
53 
54 #include "opal.h"
55 
56 #ifdef FDT
57 #include <dev/ofw/ofw_bus.h>
58 #include <dev/ofw/ofw_bus_subr.h>
59 #endif
60 
61 struct opal_i2c_softc
62 {
63 	device_t dev;
64 	device_t iicbus;
65 	uint32_t opal_id;
66 	struct mtx sc_mtx;
67 };
68 
69 /* OPAL I2C request */
70 struct opal_i2c_request {
71 	uint8_t type;
72 #define OPAL_I2C_RAW_READ	0
73 #define OPAL_I2C_RAW_WRITE	1
74 #define OPAL_I2C_SM_READ	2
75 #define OPAL_I2C_SM_WRITE	3
76 	uint8_t flags;
77 	uint8_t	subaddr_sz;		/* Max 4 */
78 	uint8_t reserved;
79 	uint16_t addr;			/* 7 or 10 bit address */
80 	uint16_t reserved2;
81 	uint32_t subaddr;		/* Sub-address if any */
82 	uint32_t size;			/* Data size */
83 	uint64_t buffer_pa;		/* Buffer real address */
84 };
85 
86 static int opal_i2c_attach(device_t);
87 static int opal_i2c_callback(device_t, int, caddr_t);
88 static int opal_i2c_probe(device_t);
89 static int opal_i2c_transfer(device_t, struct iic_msg *, uint32_t);
90 static int i2c_opal_send_request(uint32_t, struct opal_i2c_request *);
91 static phandle_t opal_i2c_get_node(device_t bus, device_t dev);
92 
93 static device_method_t opal_i2c_methods[] = {
94 	/* Device interface */
95 	DEVMETHOD(device_probe,		opal_i2c_probe),
96 	DEVMETHOD(device_attach,	opal_i2c_attach),
97 
98 	/* iicbus interface */
99 	DEVMETHOD(iicbus_callback,	opal_i2c_callback),
100 	DEVMETHOD(iicbus_transfer,	opal_i2c_transfer),
101 	DEVMETHOD(ofw_bus_get_node,	opal_i2c_get_node),
102 	DEVMETHOD_END
103 };
104 
105 #define	I2C_LOCK(_sc)		mtx_lock(&(_sc)->sc_mtx)
106 #define	I2C_UNLOCK(_sc)		mtx_unlock(&(_sc)->sc_mtx)
107 #define	I2C_LOCK_INIT(_sc) \
108 	mtx_init(&_sc->sc_mtx, device_get_nameunit(_sc->dev), \
109 	    "i2c", MTX_DEF)
110 
111 static driver_t opal_i2c_driver = {
112 	"iichb",
113 	opal_i2c_methods,
114 	sizeof(struct opal_i2c_softc),
115 };
116 
117 static int
118 opal_i2c_probe(device_t dev)
119 {
120 
121 	if (!(ofw_bus_is_compatible(dev, "ibm,opal-i2c")))
122 		return (ENXIO);
123 
124 	device_set_desc(dev, "opal-i2c");
125 
126 	return (0);
127 }
128 
129 static int
130 opal_i2c_attach(device_t dev)
131 {
132 	struct opal_i2c_softc *sc;
133 	int len;
134 
135 	sc = device_get_softc(dev);
136 	sc->dev = dev;
137 
138 	len = OF_getproplen(ofw_bus_get_node(dev), "ibm,opal-id");
139 	if (len <= 0)
140 		return (EINVAL);
141 	OF_getencprop(ofw_bus_get_node(dev), "ibm,opal-id", &sc->opal_id, len);
142 
143 	if ((sc->iicbus = device_add_child(dev, "iicbus", -1)) == NULL) {
144 		device_printf(dev, "could not allocate iicbus instance\n");
145 		return (EINVAL);
146 	}
147 
148 	I2C_LOCK_INIT(sc);
149 
150 	return (bus_generic_attach(dev));
151 }
152 
153 static int
154 opal_get_async_rc(struct opal_msg msg)
155 {
156 	if (msg.msg_type != OPAL_MSG_ASYNC_COMP)
157 		return OPAL_PARAMETER;
158 	else
159 		return htobe64(msg.params[1]);
160 }
161 
162 static int
163 i2c_opal_send_request(uint32_t bus_id, struct opal_i2c_request *req)
164 {
165 	struct opal_msg msg;
166 	uint64_t token;
167 	int rc;
168 
169 	token = opal_alloc_async_token();
170 
171 	memset(&msg, 0, sizeof(msg));
172 
173 	rc = opal_call(OPAL_I2C_REQUEST, token, bus_id,
174 	    vtophys(req));
175 	if (rc != OPAL_ASYNC_COMPLETION)
176 		goto out;
177 
178 	rc = opal_wait_completion(&msg, sizeof(msg), token);
179 
180 	if (rc != OPAL_SUCCESS)
181 		goto out;
182 
183 	rc = opal_get_async_rc(msg);
184 
185 out:
186 	opal_free_async_token(token);
187 
188 	return (rc);
189 }
190 
191 static int
192 opal_i2c_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
193 {
194 	struct opal_i2c_softc *sc;
195 	int i, err = 0;
196 	struct opal_i2c_request req;
197 
198 	sc = device_get_softc(dev);
199 
200 	memset(&req, 0, sizeof(req));
201 
202 	I2C_LOCK(sc);
203 	for (i = 0; i < nmsgs; i++) {
204 		req.type = (msgs[i].flags & IIC_M_RD) ?
205 		    OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE;
206 		req.addr = htobe16(msgs[i].slave >> 1);
207 		req.size = htobe32(msgs[i].len);
208 		req.buffer_pa = htobe64(pmap_kextract((uint64_t)msgs[i].buf));
209 
210 		err = i2c_opal_send_request(sc->opal_id, &req);
211 	}
212 	I2C_UNLOCK(sc);
213 
214 	return (err);
215 }
216 
217 static int
218 opal_i2c_callback(device_t dev, int index, caddr_t data)
219 {
220 	int error = 0;
221 
222 	switch (index) {
223 	case IIC_REQUEST_BUS:
224 		break;
225 
226 	case IIC_RELEASE_BUS:
227 		break;
228 
229 	default:
230 		error = EINVAL;
231 	}
232 
233 	return (error);
234 }
235 
236 static phandle_t
237 opal_i2c_get_node(device_t bus, device_t dev)
238 {
239 
240 	/* Share controller node with iibus device. */
241 	return (ofw_bus_get_node(bus));
242 }
243 
244 DRIVER_MODULE(opal_i2c, opal_i2cm, opal_i2c_driver, NULL, NULL);
245 DRIVER_MODULE(iicbus, opal_i2c, iicbus_driver, NULL, NULL);
246 MODULE_DEPEND(opal_i2c, iicbus, 1, 1, 1);
247