1 /*-
2  * Copyright (c) 2019 Juniper Networks, Inc.
3  * Copyright (c) 2019 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 ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
19  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
20  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
23  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
24  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25  * POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/param.h>
29 #include <sys/bus.h>
30 #include <sys/kernel.h>
31 #include <sys/module.h>
32 #include <sys/rman.h>
33 #include <sys/systm.h>
34 
35 #include <dev/fdt/simplebus.h>
36 #include <dev/ofw/ofw_bus_subr.h>
37 #include <dev/ofw/ofw_bus.h>
38 
39 #include <machine/bus.h>
40 #include <machine/resource.h>
41 
42 #include "mdio_if.h"
43 
44 #define	REG_BASE_RID	0
45 
46 #define	MDIO_RATE_ADJ_EXT_OFFSET	0x000
47 #define	MDIO_RATE_ADJ_INT_OFFSET	0x004
48 #define	MDIO_RATE_ADJ_DIVIDENT_SHIFT	16
49 
50 #define	MDIO_SCAN_CTRL_OFFSET		0x008
51 #define	MDIO_SCAN_CTRL_OVRIDE_EXT_MSTR	28
52 
53 #define	MDIO_PARAM_OFFSET		0x23c
54 #define	MDIO_PARAM_MIIM_CYCLE		29
55 #define	MDIO_PARAM_INTERNAL_SEL		25
56 #define	MDIO_PARAM_BUS_ID		22
57 #define	MDIO_PARAM_C45_SEL		21
58 #define	MDIO_PARAM_PHY_ID		16
59 #define	MDIO_PARAM_PHY_DATA		0
60 
61 #define	MDIO_READ_OFFSET		0x240
62 #define	MDIO_READ_DATA_MASK		0xffff
63 #define	MDIO_ADDR_OFFSET		0x244
64 
65 #define	MDIO_CTRL_OFFSET		0x248
66 #define	MDIO_CTRL_WRITE_OP		0x1
67 #define	MDIO_CTRL_READ_OP		0x2
68 
69 #define	MDIO_STAT_OFFSET		0x24c
70 #define	MDIO_STAT_DONE			1
71 
72 #define	BUS_MAX_ADDR			32
73 #define	EXT_BUS_START_ADDR		16
74 
75 #define	MDIO_REG_ADDR_SPACE_SIZE	0x250
76 
77 #define	MDIO_OPERATING_FREQUENCY	11000000
78 #define	MDIO_RATE_ADJ_DIVIDENT		1
79 
80 #define	MII_ADDR_C45			(1<<30)
81 
82 static int brcm_iproc_mdio_probe(device_t);
83 static int brcm_iproc_mdio_attach(device_t);
84 static int brcm_iproc_mdio_detach(device_t);
85 
86 /* OFW bus interface */
87 struct brcm_mdio_ofw_devinfo {
88 	struct ofw_bus_devinfo	di_dinfo;
89 	struct resource_list	di_rl;
90 };
91 
92 struct brcm_iproc_mdio_softc {
93 	struct simplebus_softc	sbus;
94 	device_t		dev;
95 	struct resource *	reg_base;
96 	uint32_t		clock_rate;
97 };
98 
99 MALLOC_DEFINE(M_BRCM_IPROC_MDIO, "Broadcom IPROC MDIO",
100     "Broadcom IPROC MDIO dynamic memory");
101 
102 static int brcm_iproc_config(struct brcm_iproc_mdio_softc*);
103 static const struct ofw_bus_devinfo *
104 brcm_iproc_mdio_get_devinfo(device_t, device_t);
105 static int brcm_iproc_mdio_write_mux(device_t, int, int, int, int);
106 static int brcm_iproc_mdio_read_mux(device_t, int, int, int);
107 
108 static device_method_t brcm_iproc_mdio_fdt_methods[] = {
109 	/* Device interface */
110 	DEVMETHOD(device_probe,		brcm_iproc_mdio_probe),
111 	DEVMETHOD(device_attach,	brcm_iproc_mdio_attach),
112 	DEVMETHOD(device_detach,	brcm_iproc_mdio_detach),
113 
114 	/* Bus interface */
115 	DEVMETHOD(bus_alloc_resource,		bus_generic_alloc_resource),
116 	DEVMETHOD(bus_release_resource,		bus_generic_release_resource),
117 	DEVMETHOD(bus_activate_resource,	bus_generic_activate_resource),
118 
119 	/* ofw_bus interface */
120 	DEVMETHOD(ofw_bus_get_devinfo,	brcm_iproc_mdio_get_devinfo),
121 	DEVMETHOD(ofw_bus_get_compat,	ofw_bus_gen_get_compat),
122 	DEVMETHOD(ofw_bus_get_model,	ofw_bus_gen_get_model),
123 	DEVMETHOD(ofw_bus_get_name,	ofw_bus_gen_get_name),
124 	DEVMETHOD(ofw_bus_get_node,	ofw_bus_gen_get_node),
125 	DEVMETHOD(ofw_bus_get_type,	ofw_bus_gen_get_type),
126 
127 	/* MDIO interface */
128 	DEVMETHOD(mdio_writereg_mux,	brcm_iproc_mdio_write_mux),
129 	DEVMETHOD(mdio_readreg_mux,	brcm_iproc_mdio_read_mux),
130 
131 	/* End */
132 	DEVMETHOD_END
133 };
134 
135 DEFINE_CLASS_0(brcm_iproc_mdio, brcm_iproc_mdio_driver,
136     brcm_iproc_mdio_fdt_methods, sizeof(struct brcm_iproc_mdio_softc));
137 
138 EARLY_DRIVER_MODULE(brcm_iproc_mdio, ofwbus, brcm_iproc_mdio_driver, 0, 0,
139     BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
140 EARLY_DRIVER_MODULE(brcm_iproc_mdio, simplebus, brcm_iproc_mdio_driver, 0, 0,
141     BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
142 
143 static struct ofw_compat_data mdio_compat_data[] = {
144 	{"brcm,mdio-mux-iproc",	true},
145 	{NULL,			false}
146 };
147 
148 static int
149 brcm_iproc_switch(struct brcm_iproc_mdio_softc *sc, int child)
150 {
151 	uint32_t param, bus_id;
152 	uint32_t bus_dir;
153 
154 	/* select bus and its properties */
155 	bus_dir = (child < EXT_BUS_START_ADDR);
156 	bus_id = bus_dir ? child : (child - EXT_BUS_START_ADDR);
157 
158 	param = (bus_dir ? 1 : 0) << MDIO_PARAM_INTERNAL_SEL;
159 	param |= (bus_id << MDIO_PARAM_BUS_ID);
160 
161 	bus_write_4(sc->reg_base, MDIO_PARAM_OFFSET, param);
162 
163 	return (0);
164 }
165 
166 static int
167 iproc_mdio_wait_for_idle(struct brcm_iproc_mdio_softc *sc, uint32_t result)
168 {
169 	unsigned int timeout = 1000; /* loop for 1s */
170 	uint32_t val;
171 
172 	do {
173 		val = bus_read_4(sc->reg_base, MDIO_STAT_OFFSET);
174 		if ((val & MDIO_STAT_DONE) == result)
175 			return (0);
176 
177 		pause("BRCM MDIO SLEEP", 1000 / hz);
178 	} while (timeout--);
179 
180 	return (ETIMEDOUT);
181 }
182 
183 /* start_miim_ops- Program and start MDIO transaction over mdio bus.
184  * @base: Base address
185  * @phyid: phyid of the selected bus.
186  * @reg: register offset to be read/written.
187  * @val :0 if read op else value to be written in @reg;
188  * @op: Operation that need to be carried out.
189  *      MDIO_CTRL_READ_OP: Read transaction.
190  *      MDIO_CTRL_WRITE_OP: Write transaction.
191  *
192  * Return value: Successful Read operation returns read reg values and write
193  *      operation returns 0. Failure operation returns negative error code.
194  */
195 static int
196 brcm_iproc_mdio_op(struct brcm_iproc_mdio_softc *sc,
197 	uint16_t phyid, uint32_t reg, uint32_t val, uint32_t op)
198 {
199 	uint32_t param;
200 	int ret;
201 
202 	bus_write_4(sc->reg_base, MDIO_CTRL_OFFSET, 0);
203 	bus_read_4(sc->reg_base, MDIO_STAT_OFFSET);
204 	ret = iproc_mdio_wait_for_idle(sc, 0);
205 	if (ret)
206 		goto err;
207 
208 	param = bus_read_4(sc->reg_base, MDIO_PARAM_OFFSET);
209 	param |= phyid << MDIO_PARAM_PHY_ID;
210 	param |= val << MDIO_PARAM_PHY_DATA;
211 	if (reg & MII_ADDR_C45)
212 		param |= (1 << MDIO_PARAM_C45_SEL);
213 
214 	bus_write_4(sc->reg_base, MDIO_PARAM_OFFSET, param);
215 
216 	bus_write_4(sc->reg_base, MDIO_ADDR_OFFSET, reg);
217 
218 	bus_write_4(sc->reg_base, MDIO_CTRL_OFFSET, op);
219 
220 	ret = iproc_mdio_wait_for_idle(sc, 1);
221 	if (ret)
222 		goto err;
223 
224 	if (op == MDIO_CTRL_READ_OP)
225 		ret = bus_read_4(sc->reg_base, MDIO_READ_OFFSET) & MDIO_READ_DATA_MASK;
226 err:
227 	return ret;
228 }
229 
230 static int
231 brcm_iproc_config(struct brcm_iproc_mdio_softc *sc)
232 {
233 	uint32_t divisor;
234 	uint32_t val;
235 
236 	/* Disable external mdio master access */
237 	val = bus_read_4(sc->reg_base, MDIO_SCAN_CTRL_OFFSET);
238 	val |= 1 << MDIO_SCAN_CTRL_OVRIDE_EXT_MSTR;
239 	bus_write_4(sc->reg_base, MDIO_SCAN_CTRL_OFFSET, val);
240 
241 	if (sc->clock_rate) {
242 		/* use rate adjust regs to derrive the mdio's operating
243 		 * frequency from the specified core clock
244 		 */
245 		divisor = sc->clock_rate / MDIO_OPERATING_FREQUENCY;
246 		divisor = divisor / (MDIO_RATE_ADJ_DIVIDENT + 1);
247 		val = divisor;
248 		val |= MDIO_RATE_ADJ_DIVIDENT << MDIO_RATE_ADJ_DIVIDENT_SHIFT;
249 		bus_write_4(sc->reg_base, MDIO_RATE_ADJ_EXT_OFFSET, val);
250 		bus_write_4(sc->reg_base, MDIO_RATE_ADJ_INT_OFFSET, val);
251 	}
252 
253 	return (0);
254 }
255 
256 static int
257 brcm_iproc_mdio_write_mux(device_t dev, int bus, int phy, int reg, int val)
258 {
259 	struct brcm_iproc_mdio_softc *sc;
260 
261 	sc = device_get_softc(dev);
262 
263 	if (brcm_iproc_switch(sc, bus) != 0) {
264 		device_printf(dev, "Failed to set BUS MUX\n");
265 		return (EINVAL);
266 	}
267 
268 	return (brcm_iproc_mdio_op(sc, phy, reg, val, MDIO_CTRL_WRITE_OP));
269 }
270 
271 static int
272 brcm_iproc_mdio_read_mux(device_t dev, int bus, int phy, int reg)
273 {
274 	struct brcm_iproc_mdio_softc *sc;
275 
276 	sc = device_get_softc(dev);
277 
278 	if (brcm_iproc_switch(sc, bus) != 0) {
279 		device_printf(dev, "Failed to set BUS MUX\n");
280 		return (EINVAL);
281 	}
282 
283 	return (brcm_iproc_mdio_op(sc, phy, reg, 0, MDIO_CTRL_READ_OP));
284 }
285 
286 static int
287 brcm_iproc_mdio_probe(device_t dev)
288 {
289 
290 	if (!ofw_bus_status_okay(dev))
291 		return (ENXIO);
292 	if (!ofw_bus_search_compatible(dev, mdio_compat_data)->ocd_data)
293 		return (ENXIO);
294 
295 	device_set_desc(dev, "Broadcom MDIO MUX driver");
296 	return (BUS_PROBE_DEFAULT);
297 }
298 
299 static int
300 brcm_iproc_mdio_attach(device_t dev)
301 {
302 	struct brcm_iproc_mdio_softc *sc;
303 	phandle_t node, parent;
304 	struct brcm_mdio_ofw_devinfo *di;
305 	int rid;
306 	device_t child;
307 
308 	sc = device_get_softc(dev);
309 	sc->dev = dev;
310 
311 	/* Allocate memory resources */
312 	rid = REG_BASE_RID;
313 	sc->reg_base = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
314 	    RF_ACTIVE);
315 	if (sc->reg_base == NULL) {
316 		device_printf(dev, "Could not allocate memory\n");
317 		return (ENXIO);
318 	}
319 
320 	/* Configure MDIO controlled */
321 	if (brcm_iproc_config(sc) < 0) {
322 		device_printf(dev, "Unable to initialize IPROC MDIO\n");
323 		goto error;
324 	}
325 
326 	parent = ofw_bus_get_node(dev);
327 	simplebus_init(dev, parent);
328 
329 	/* Iterate through all bus subordinates */
330 	for (node = OF_child(parent); node > 0; node = OF_peer(node)) {
331 		/* Allocate and populate devinfo. */
332 		di = malloc(sizeof(*di), M_BRCM_IPROC_MDIO, M_WAITOK | M_ZERO);
333 		if (ofw_bus_gen_setup_devinfo(&di->di_dinfo, node) != 0) {
334 			free(di, M_BRCM_IPROC_MDIO);
335 			continue;
336 		}
337 
338 		/* Initialize and populate resource list. */
339 		resource_list_init(&di->di_rl);
340 		ofw_bus_reg_to_rl(dev, node, sc->sbus.acells, sc->sbus.scells,
341 		    &di->di_rl);
342 		ofw_bus_intr_to_rl(dev, node, &di->di_rl, NULL);
343 
344 		/* Add newbus device for this FDT node */
345 		child = device_add_child(dev, NULL, -1);
346 		if (child == NULL) {
347 			printf("Failed to add child\n");
348 			resource_list_free(&di->di_rl);
349 			ofw_bus_gen_destroy_devinfo(&di->di_dinfo);
350 			free(di, M_BRCM_IPROC_MDIO);
351 			continue;
352 		}
353 
354 		device_set_ivars(child, di);
355 	}
356 
357 	/*
358 	 * Register device to this node/xref.
359 	 * Thanks to that we will be able to retrieve device_t structure
360 	 * while holding only node reference acquired from FDT.
361 	 */
362 	node = ofw_bus_get_node(dev);
363 	OF_device_register_xref(OF_xref_from_node(node), dev);
364 
365 	return (bus_generic_attach(dev));
366 
367 error:
368 	brcm_iproc_mdio_detach(dev);
369 	return (ENXIO);
370 }
371 
372 static const struct ofw_bus_devinfo *
373 brcm_iproc_mdio_get_devinfo(device_t bus __unused, device_t child)
374 {
375 	struct brcm_mdio_ofw_devinfo *di;
376 
377 	di = device_get_ivars(child);
378 	return (&di->di_dinfo);
379 }
380 
381 static int
382 brcm_iproc_mdio_detach(device_t dev)
383 {
384 	struct brcm_iproc_mdio_softc *sc;
385 
386 	sc = device_get_softc(dev);
387 
388 	if (sc->reg_base != NULL) {
389 		bus_release_resource(dev, SYS_RES_MEMORY, REG_BASE_RID,
390 		    sc->reg_base);
391 	}
392 
393 	return (0);
394 }
395