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
62static int
63qcom_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
77static int
78qcom_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
90static void
91qcom_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
101static int
102qcom_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);
141error:
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 */
157static int
158qcom_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
178static void
179qcom_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
190static int
191qcom_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
232static int
233qcom_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
270static 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
286static driver_t qcom_mdio_ipq4018_driver = {
287	"mdio",
288	qcom_mdio_ipq4018_methods,
289	sizeof(struct qcom_mdio_ipq4018_softc),
290};
291
292EARLY_DRIVER_MODULE(qcom_mdio_ipq4018, simplebus, qcom_mdio_ipq4018_driver,
293    NULL, NULL, BUS_PASS_SUPPORTDEV + BUS_PASS_ORDER_LATE);
294
295MODULE_DEPEND(qcom_mdio_ipq4018, ether, 1, 1, 1);
296MODULE_DEPEND(qcom_mdio_ipq4018, mdio, 1, 1, 1);
297MODULE_DEPEND(qcom_mdio_ipq4018, miibus, 1, 1, 1);
298
299MODULE_VERSION(qcom_mdio_ipq4018, 1);
300