xref: /freebsd/sys/dev/qcom_mdio/qcom_mdio_ipq4018.c (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2022 Adrian Chadd <adrian@FreeBSD.org>
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 unmodified, this list of conditions, and the following
11  *    disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*
30  * This is the MDIO controller for the IPQ4018/IPQ4019.
31  */
32 
33 #include <sys/cdefs.h>
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/bus.h>
38 
39 #include <sys/kernel.h>
40 #include <sys/module.h>
41 #include <sys/rman.h>
42 #include <sys/lock.h>
43 #include <sys/malloc.h>
44 #include <sys/mutex.h>
45 #include <sys/gpio.h>
46 
47 #include <machine/bus.h>
48 #include <machine/resource.h>
49 #include <dev/gpio/gpiobusvar.h>
50 
51 #include <dev/fdt/fdt_common.h>
52 #include <dev/ofw/ofw_bus.h>
53 #include <dev/ofw/ofw_bus_subr.h>
54 
55 #include "mdio_if.h"
56 
57 #include <dev/qcom_mdio/qcom_mdio_ipq4018_var.h>
58 #include <dev/qcom_mdio/qcom_mdio_ipq4018_reg.h>
59 
60 #include <dev/qcom_mdio/qcom_mdio_debug.h>
61 
62 static int
63 qcom_mdio_ipq4018_probe(device_t dev)
64 {
65 
66 	if (! ofw_bus_status_okay(dev))
67 		return (ENXIO);
68 
69 	if (ofw_bus_is_compatible(dev, "qcom,ipq4019-mdio") == 0)
70 		return (ENXIO);
71 
72 	device_set_desc(dev,
73 	    "Qualcomm Atheros IPQ4018/IPQ4019 MDIO driver");
74 	return (0);
75 }
76 
77 static int
78 qcom_mdio_ipq4018_detach(device_t dev)
79 {
80 	struct qcom_mdio_ipq4018_softc *sc = device_get_softc(dev);
81 
82 	if (sc->sc_mem_res != NULL)
83 		bus_release_resource(dev, SYS_RES_MEMORY, sc->sc_mem_rid,
84 		    sc->sc_mem_res);
85 	mtx_destroy(&sc->sc_mtx);
86 
87 	return (0);
88 }
89 
90 static void
91 qcom_mdio_sysctl_attach(struct qcom_mdio_ipq4018_softc *sc)
92 {
93 	struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
94 	struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
95 
96 	SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
97 	    "debug", CTLFLAG_RW, &sc->sc_debug, 0,
98 	    "control debugging printfs");
99 }
100 
101 static int
102 qcom_mdio_ipq4018_attach(device_t dev)
103 {
104 	phandle_t node;
105 	struct qcom_mdio_ipq4018_softc *sc = device_get_softc(dev);
106 	int error = 0;
107 
108 	node = ofw_bus_get_node(dev);
109 
110 	sc->sc_dev = dev;
111 	sc->sc_debug = 0;
112 	mtx_init(&sc->sc_mtx, device_get_nameunit(dev), NULL, MTX_DEF);
113 
114 	/*
115 	 * Map the MDIO memory region.
116 	 */
117 	sc->sc_mem_rid = 0;
118 	sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
119 	    &sc->sc_mem_rid, RF_ACTIVE);
120 	if (sc->sc_mem_res == NULL) {
121 		error = ENXIO;
122 		device_printf(dev, "%s: failed to map device memory\n",
123 		    __func__);
124 		goto error;
125 	}
126 	sc->sc_mem_res_size = (size_t) bus_get_resource_count(dev,
127 	    SYS_RES_MEMORY, sc->sc_mem_rid);
128 	if (sc->sc_mem_res_size == 0) {
129 		error = ENXIO;
130 		device_printf(dev, "%s: failed to get device memory size\n",
131 		    __func__);
132 		goto error;
133 
134 	}
135 
136 	qcom_mdio_sysctl_attach(sc);
137 
138 	OF_device_register_xref(OF_xref_from_node(node), dev);
139 
140 	return (0);
141 error:
142 	if (sc->sc_mem_res != NULL)
143 		bus_release_resource(dev, SYS_RES_MEMORY, sc->sc_mem_rid,
144 		    sc->sc_mem_res);
145 
146 	mtx_destroy(&sc->sc_mtx);
147 	return (error);
148 }
149 
150 /*
151  * Wait for the BUSY flag to become zero.
152  *
153  * This has to happen before every MDIO transfer.
154  *
155  * Returns 0 if OK, error if error/timed out.
156  */
157 static int
158 qcom_mdio_ipq4018_wait(struct qcom_mdio_ipq4018_softc *sc)
159 {
160 	int i;
161 	uint32_t reg;
162 
163 	MDIO_LOCK_ASSERT(sc);
164 
165 	for (i = 0; i < QCOM_IPQ4018_MDIO_SLEEP_COUNT; i++) {
166 		MDIO_BARRIER_READ(sc);
167 
168 		reg = MDIO_READ(sc, QCOM_IPQ4018_MDIO_REG_CMD);
169 		if ((reg & QCOM_IPQ4018_MDIO_REG_CMD_ACCESS_BUSY) == 0)
170 			return (0);
171 		DELAY(QCOM_IPQ4018_MDIO_SLEEP);
172 	}
173 	device_printf(sc->sc_dev, "%s: warning: timeout waiting for bus\n",
174 	    __func__);
175 	return (ETIMEDOUT);
176 }
177 
178 static void
179 qcom_mdio_ipq4018_set_phy_reg_addr(struct qcom_mdio_ipq4018_softc *sc,
180   int phy, int reg)
181 {
182 
183 	MDIO_LOCK_ASSERT(sc);
184 
185 	MDIO_WRITE(sc, QCOM_IPQ4018_MDIO_REG_ADDR,
186 	    ((phy & 0xff) << 8) | (reg & 0xff));
187 	MDIO_BARRIER_WRITE(sc);
188 }
189 
190 static int
191 qcom_mdio_ipq4018_readreg(device_t dev, int phy, int reg)
192 {
193 	struct qcom_mdio_ipq4018_softc *sc = device_get_softc(dev);
194 	uint32_t ret;
195 
196 	QCOM_MDIO_DPRINTF(sc, QCOM_MDIO_DEBUG_REG_READ,
197 	    "%s: called; phy=0x%x reg=0x%x\n",
198 	    __func__, phy, reg);
199 
200 	MDIO_LOCK(sc);
201 	if (qcom_mdio_ipq4018_wait(sc) != 0) {
202 		MDIO_UNLOCK(sc);
203 		return (-1);
204 	}
205 
206 	/* Set phy/reg values */
207 	qcom_mdio_ipq4018_set_phy_reg_addr(sc, phy, reg);
208 
209 	/* Issue read command */
210 	MDIO_WRITE(sc, QCOM_IPQ4018_MDIO_REG_CMD,
211 	    QCOM_IPQ4018_MDIO_REG_CMD_ACCESS_START |
212 	    QCOM_IPQ4018_MDIO_REG_CMD_ACCESS_CODE_READ);
213 	MDIO_BARRIER_WRITE(sc);
214 
215 	/* Wait for completion */
216 	if (qcom_mdio_ipq4018_wait(sc) != 0) {
217 		MDIO_UNLOCK(sc);
218 		return (-1);
219 	}
220 
221 	/* Fetch return register value */
222 	MDIO_BARRIER_READ(sc);
223 	ret = MDIO_READ(sc, QCOM_IPQ4018_MDIO_REG_READ);
224 	MDIO_UNLOCK(sc);
225 
226 	QCOM_MDIO_DPRINTF(sc, QCOM_MDIO_DEBUG_REG_READ,
227 	    "%s: -> 0x%x\n", __func__, ret);
228 
229 	return (ret);
230 }
231 
232 static int
233 qcom_mdio_ipq4018_writereg(device_t dev, int phy, int reg, int value)
234 {
235 	struct qcom_mdio_ipq4018_softc *sc = device_get_softc(dev);
236 
237 	QCOM_MDIO_DPRINTF(sc, QCOM_MDIO_DEBUG_REG_WRITE,
238 	    "%s: called; phy=0x%x reg=0x%x val=0x%x\n",
239 	    __func__, phy, reg, value);
240 
241 	MDIO_LOCK(sc);
242 	if (qcom_mdio_ipq4018_wait(sc) != 0) {
243 		MDIO_UNLOCK(sc);
244 		return (-1);
245 	}
246 
247 	/* Set phy/reg values */
248 	qcom_mdio_ipq4018_set_phy_reg_addr(sc, phy, reg);
249 
250 	/* Write command */
251 	MDIO_WRITE(sc, QCOM_IPQ4018_MDIO_REG_WRITE, value);
252 	MDIO_BARRIER_WRITE(sc);
253 
254 	/* Issue write command */
255 	MDIO_WRITE(sc, QCOM_IPQ4018_MDIO_REG_CMD,
256 	    QCOM_IPQ4018_MDIO_REG_CMD_ACCESS_START |
257 	    QCOM_IPQ4018_MDIO_REG_CMD_ACCESS_CODE_WRITE);
258 	MDIO_BARRIER_WRITE(sc);
259 
260 	/* Wait for completion */
261 	if (qcom_mdio_ipq4018_wait(sc) != 0) {
262 		MDIO_UNLOCK(sc);
263 		return (-1);
264 	}
265 	MDIO_UNLOCK(sc);
266 
267 	return (0);
268 }
269 
270 static device_method_t qcom_mdio_ipq4018_methods[] = {
271 	/* Driver */
272 	DEVMETHOD(device_probe, qcom_mdio_ipq4018_probe),
273 	DEVMETHOD(device_attach, qcom_mdio_ipq4018_attach),
274 	DEVMETHOD(device_detach, qcom_mdio_ipq4018_detach),
275 
276 	/* Bus interface */
277 	DEVMETHOD(bus_add_child, bus_generic_add_child),
278 
279 	/* MDIO interface */
280 	DEVMETHOD(mdio_readreg, qcom_mdio_ipq4018_readreg),
281 	DEVMETHOD(mdio_writereg, qcom_mdio_ipq4018_writereg),
282 
283 	{0, 0},
284 };
285 
286 static driver_t qcom_mdio_ipq4018_driver = {
287 	"mdio",
288 	qcom_mdio_ipq4018_methods,
289 	sizeof(struct qcom_mdio_ipq4018_softc),
290 };
291 
292 EARLY_DRIVER_MODULE(qcom_mdio_ipq4018, simplebus, qcom_mdio_ipq4018_driver,
293     NULL, NULL, BUS_PASS_SUPPORTDEV + BUS_PASS_ORDER_LATE);
294 
295 MODULE_DEPEND(qcom_mdio_ipq4018, ether, 1, 1, 1);
296 MODULE_DEPEND(qcom_mdio_ipq4018, mdio, 1, 1, 1);
297 MODULE_DEPEND(qcom_mdio_ipq4018, miibus, 1, 1, 1);
298 
299 MODULE_VERSION(qcom_mdio_ipq4018, 1);
300