xref: /freebsd/sys/riscv/sifive/fu740_pci_dw.c (revision ba3c1f5972d7b90feb6e6da47905ff2757e0fe57)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright 2021 Jessica Clarke <jrtc27@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, 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 
29 /* SiFive FU740 DesignWare PCIe driver */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/bus.h>
37 #include <sys/gpio.h>
38 #include <sys/kernel.h>
39 #include <sys/module.h>
40 #include <sys/rman.h>
41 
42 #include <machine/bus.h>
43 #include <machine/intr.h>
44 #include <machine/resource.h>
45 
46 #include <dev/extres/clk/clk.h>
47 #include <dev/extres/hwreset/hwreset.h>
48 #include <dev/gpio/gpiobusvar.h>
49 #include <dev/ofw/ofw_bus.h>
50 #include <dev/ofw/ofw_bus_subr.h>
51 #include <dev/ofw/ofw_pci.h>
52 #include <dev/ofw/ofwpci.h>
53 #include <dev/pci/pcivar.h>
54 #include <dev/pci/pcireg.h>
55 #include <dev/pci/pcib_private.h>
56 #include <dev/pci/pci_dw.h>
57 
58 #include "pcib_if.h"
59 #include "pci_dw_if.h"
60 
61 #define	FUDW_PHYS		2
62 #define	FUDW_LANES_PER_PHY	4
63 
64 #define	FUDW_MGMT_PERST_N			0x0
65 #define	FUDW_MGMT_LTSSM_EN			0x10
66 #define	FUDW_MGMT_HOLD_PHY_RST			0x18
67 #define	FUDW_MGMT_DEVICE_TYPE			0x708
68 #define	 FUDW_MGMT_DEVICE_TYPE_RC			0x4
69 #define	FUDW_MGMT_PHY_CR_PARA_REG(_n, _r)	\
70     (0x860 + (_n) * 0x40 + FUDW_MGMT_PHY_CR_PARA_##_r)
71 #define	 FUDW_MGMT_PHY_CR_PARA_ADDR			0x0
72 #define	 FUDW_MGMT_PHY_CR_PARA_READ_EN			0x10
73 #define	 FUDW_MGMT_PHY_CR_PARA_READ_DATA		0x18
74 #define	 FUDW_MGMT_PHY_CR_PARA_SEL			0x20
75 #define	 FUDW_MGMT_PHY_CR_PARA_WRITE_DATA		0x28
76 #define	 FUDW_MGMT_PHY_CR_PARA_WRITE_EN			0x30
77 #define	 FUDW_MGMT_PHY_CR_PARA_ACK			0x38
78 
79 #define	FUDW_MGMT_PHY_LANE(_n)			(0x1008 + (_n) * 0x100)
80 #define	 FUDW_MGMT_PHY_LANE_CDR_TRACK_EN		(1 << 0)
81 #define	 FUDW_MGMT_PHY_LANE_LOS_THRESH			(1 << 5)
82 #define	 FUDW_MGMT_PHY_LANE_TERM_EN			(1 << 9)
83 #define	 FUDW_MGMT_PHY_LANE_TERM_ACDC			(1 << 10)
84 #define	 FUDW_MGMT_PHY_LANE_EN				(1 << 11)
85 #define	 FUDW_MGMT_PHY_LANE_INIT					\
86     (FUDW_MGMT_PHY_LANE_CDR_TRACK_EN | FUDW_MGMT_PHY_LANE_LOS_THRESH |	\
87      FUDW_MGMT_PHY_LANE_TERM_EN | FUDW_MGMT_PHY_LANE_TERM_ACDC |	\
88      FUDW_MGMT_PHY_LANE_EN)
89 
90 #define	FUDW_DBI_PORT_DBG1			0x72c
91 #define	 FUDW_DBI_PORT_DBG1_LINK_UP			(1 << 4)
92 #define	 FUDW_DBI_PORT_DBG1_LINK_IN_TRAINING		(1 << 29)
93 
94 struct fupci_softc {
95 	struct pci_dw_softc	dw_sc;
96 	device_t		dev;
97 	struct resource		*mgmt_res;
98 	gpio_pin_t		porst_pin;
99 	gpio_pin_t		pwren_pin;
100 	clk_t			pcie_aux_clk;
101 	hwreset_t		pcie_aux_rst;
102 };
103 
104 #define	FUDW_MGMT_READ(_sc, _o)		bus_read_4((_sc)->mgmt_res, (_o))
105 #define	FUDW_MGMT_WRITE(_sc, _o, _v)	bus_write_4((_sc)->mgmt_res, (_o), (_v))
106 
107 static struct ofw_compat_data compat_data[] = {
108 	{ "sifive,fu740-pcie",	1 },
109 	{ NULL,			0 },
110 };
111 
112 /* Currently unused; included for completeness */
113 static int __unused
114 fupci_phy_read(struct fupci_softc *sc, int phy, uint32_t reg, uint32_t *val)
115 {
116 	unsigned timeout;
117 	uint32_t ack;
118 
119 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, ADDR), reg);
120 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, READ_EN), 1);
121 
122 	timeout = 10;
123 	do {
124 		ack = FUDW_MGMT_READ(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, ACK));
125 		if (ack != 0)
126 			break;
127 		DELAY(10);
128 	} while (--timeout > 0);
129 
130 	if (timeout == 0) {
131 		device_printf(sc->dev, "Timeout waiting for read ACK\n");
132 		return (ETIMEDOUT);
133 	}
134 
135 	*val = FUDW_MGMT_READ(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, READ_DATA));
136 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, READ_EN), 0);
137 
138 	timeout = 10;
139 	do {
140 		ack = FUDW_MGMT_READ(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, ACK));
141 		if (ack == 0)
142 			break;
143 		DELAY(10);
144 	} while (--timeout > 0);
145 
146 	if (timeout == 0) {
147 		device_printf(sc->dev, "Timeout waiting for read un-ACK\n");
148 		return (ETIMEDOUT);
149 	}
150 
151 	return (0);
152 }
153 
154 static int
155 fupci_phy_write(struct fupci_softc *sc, int phy, uint32_t reg, uint32_t val)
156 {
157 	unsigned timeout;
158 	uint32_t ack;
159 
160 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, ADDR), reg);
161 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, WRITE_DATA), val);
162 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, WRITE_EN), 1);
163 
164 	timeout = 10;
165 	do {
166 		ack = FUDW_MGMT_READ(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, ACK));
167 		if (ack != 0)
168 			break;
169 		DELAY(10);
170 	} while (--timeout > 0);
171 
172 	if (timeout == 0) {
173 		device_printf(sc->dev, "Timeout waiting for write ACK\n");
174 		return (ETIMEDOUT);
175 	}
176 
177 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, WRITE_EN), 0);
178 
179 	timeout = 10;
180 	do {
181 		ack = FUDW_MGMT_READ(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, ACK));
182 		if (ack == 0)
183 			break;
184 		DELAY(10);
185 	} while (--timeout > 0);
186 
187 	if (timeout == 0) {
188 		device_printf(sc->dev, "Timeout waiting for write un-ACK\n");
189 		return (ETIMEDOUT);
190 	}
191 
192 	return (0);
193 }
194 
195 static int
196 fupci_phy_init(struct fupci_softc *sc)
197 {
198 	device_t dev;
199 	int error, phy, lane;
200 
201 	dev = sc->dev;
202 
203 	/* Assert core power-on reset (active low) */
204 	error = gpio_pin_set_active(sc->porst_pin, false);
205 	if (error != 0) {
206 		device_printf(dev, "Cannot assert power-on reset: %d\n",
207 		    error);
208 		return (error);
209 	}
210 
211 	/* Assert PERST_N */
212 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PERST_N, 0);
213 
214 	/* Enable power */
215 	error = gpio_pin_set_active(sc->pwren_pin, true);
216 	if (error != 0) {
217 		device_printf(dev, "Cannot enable power: %d\n", error);
218 		return (error);
219 	}
220 
221 	/* Hold PERST for 100ms as per the PCIe spec */
222 	DELAY(100);
223 
224 	/* Deassert PERST_N */
225 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PERST_N, 1);
226 
227 	/* Deassert core power-on reset (active low) */
228 	error = gpio_pin_set_active(sc->porst_pin, true);
229 	if (error != 0) {
230 		device_printf(dev, "Cannot deassert power-on reset: %d\n",
231 		    error);
232 		return (error);
233 	}
234 
235 	/* Enable the aux clock */
236 	error = clk_enable(sc->pcie_aux_clk);
237 	if (error != 0) {
238 		device_printf(dev, "Cannot enable aux clock: %d\n", error);
239 		return (error);
240 	}
241 
242 	/* Hold LTSSM in reset whilst initialising the PHYs */
243 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_HOLD_PHY_RST, 1);
244 
245 	/* Deassert the aux reset */
246 	error = hwreset_deassert(sc->pcie_aux_rst);
247 	if (error != 0) {
248 		device_printf(dev, "Cannot deassert aux reset: %d\n", error);
249 		return (error);
250 	}
251 
252 	/* Enable control register interface */
253 	for (phy = 0; phy < FUDW_PHYS; ++phy)
254 		FUDW_MGMT_WRITE(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, SEL), 1);
255 
256 	/* Wait for enable to take effect */
257 	DELAY(1);
258 
259 	/* Initialise lane configuration */
260 	for (phy = 0; phy < FUDW_PHYS; ++phy) {
261 		for (lane = 0; lane < FUDW_LANES_PER_PHY; ++lane)
262 			fupci_phy_write(sc, phy, FUDW_MGMT_PHY_LANE(lane),
263 			    FUDW_MGMT_PHY_LANE_INIT);
264 	}
265 
266 	/* Disable the aux clock whilst taking the LTSSM out of reset */
267 	error = clk_disable(sc->pcie_aux_clk);
268 	if (error != 0) {
269 		device_printf(dev, "Cannot disable aux clock: %d\n", error);
270 		return (error);
271 	}
272 
273 	/* Take LTSSM out of reset */
274 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_HOLD_PHY_RST, 0);
275 
276 	/* Enable the aux clock again */
277 	error = clk_enable(sc->pcie_aux_clk);
278 	if (error != 0) {
279 		device_printf(dev, "Cannot re-enable aux clock: %d\n", error);
280 		return (error);
281 	}
282 
283 	/* Put the controller in Root Complex mode */
284 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_DEVICE_TYPE, FUDW_MGMT_DEVICE_TYPE_RC);
285 
286 	return (0);
287 }
288 
289 static void
290 fupci_dbi_protect(struct fupci_softc *sc, bool protect)
291 {
292 	uint32_t reg;
293 
294 	reg = pci_dw_dbi_rd4(sc->dev, DW_MISC_CONTROL_1);
295 	if (protect)
296 		reg &= ~DBI_RO_WR_EN;
297 	else
298 		reg |= DBI_RO_WR_EN;
299 	pci_dw_dbi_wr4(sc->dev, DW_MISC_CONTROL_1, reg);
300 }
301 
302 static int
303 fupci_init(struct fupci_softc *sc)
304 {
305 	/* Enable 32-bit I/O window */
306 	fupci_dbi_protect(sc, false);
307 	pci_dw_dbi_wr2(sc->dev, PCIR_IOBASEL_1,
308 	    (PCIM_BRIO_32 << 8) | PCIM_BRIO_32);
309 	fupci_dbi_protect(sc, true);
310 
311 	/* Enable LTSSM */
312 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_LTSSM_EN, 1);
313 
314 	return (0);
315 }
316 
317 static int
318 fupci_probe(device_t dev)
319 {
320 	if (!ofw_bus_status_okay(dev))
321 		return (ENXIO);
322 
323 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
324 		return (ENXIO);
325 
326 	device_set_desc(dev, "SiFive FU740 PCIe Controller");
327 
328 	return (BUS_PROBE_DEFAULT);
329 }
330 
331 static int
332 fupci_attach(device_t dev)
333 {
334 	struct fupci_softc *sc;
335 	phandle_t node;
336 	int error, rid;
337 
338 	sc = device_get_softc(dev);
339 	node = ofw_bus_get_node(dev);
340 	sc->dev = dev;
341 
342 	rid = 0;
343 	error = ofw_bus_find_string_index(node, "reg-names", "dbi", &rid);
344 	if (error != 0) {
345 		device_printf(dev, "Cannot get DBI memory: %d\n", error);
346 		goto fail;
347 	}
348 	sc->dw_sc.dbi_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
349 	    RF_ACTIVE);
350 	if (sc->dw_sc.dbi_res == NULL) {
351 		device_printf(dev, "Cannot allocate DBI memory\n");
352 		error = ENXIO;
353 		goto fail;
354 	}
355 
356 	rid = 0;
357 	error = ofw_bus_find_string_index(node, "reg-names", "mgmt", &rid);
358 	if (error != 0) {
359 		device_printf(dev, "Cannot get management space memory: %d\n",
360 		    error);
361 		goto fail;
362 	}
363 	sc->mgmt_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
364 	    RF_ACTIVE);
365 	if (sc->mgmt_res == NULL) {
366 		device_printf(dev, "Cannot allocate management space memory\n");
367 		error = ENXIO;
368 		goto fail;
369 	}
370 
371 	error = gpio_pin_get_by_ofw_property(dev, node, "reset-gpios",
372 	    &sc->porst_pin);
373 	/* Old U-Boot device tree uses perstn-gpios */
374 	if (error == ENOENT)
375 		error = gpio_pin_get_by_ofw_property(dev, node, "perstn-gpios",
376 		    &sc->porst_pin);
377 	if (error != 0) {
378 		device_printf(dev, "Cannot get power-on reset GPIO: %d\n",
379 		    error);
380 		goto fail;
381 	}
382 	error = gpio_pin_setflags(sc->porst_pin, GPIO_PIN_OUTPUT);
383 	if (error != 0) {
384 		device_printf(dev, "Cannot configure power-on reset GPIO: %d\n",
385 		    error);
386 		goto fail;
387 	}
388 
389 	error = gpio_pin_get_by_ofw_property(dev, node, "pwren-gpios",
390 	    &sc->pwren_pin);
391 	if (error != 0) {
392 		device_printf(dev, "Cannot get power enable GPIO: %d\n",
393 		    error);
394 		goto fail;
395 	}
396 	error = gpio_pin_setflags(sc->pwren_pin, GPIO_PIN_OUTPUT);
397 	if (error != 0) {
398 		device_printf(dev, "Cannot configure power enable GPIO: %d\n",
399 		    error);
400 		goto fail;
401 	}
402 
403 	error = clk_get_by_ofw_name(dev, node, "pcie_aux", &sc->pcie_aux_clk);
404 	/* Old U-Boot device tree uses pcieaux */
405 	if (error == ENOENT)
406 		error = clk_get_by_ofw_name(dev, node, "pcieaux",
407 		    &sc->pcie_aux_clk);
408 	if (error != 0) {
409 		device_printf(dev, "Cannot get aux clock: %d\n", error);
410 		goto fail;
411 	}
412 
413 	error = hwreset_get_by_ofw_idx(dev, node, 0, &sc->pcie_aux_rst);
414 	if (error != 0) {
415 		device_printf(dev, "Cannot get aux reset: %d\n", error);
416 		goto fail;
417 	}
418 
419 	error = fupci_phy_init(sc);
420 	if (error != 0)
421 		goto fail;
422 
423 	error = pci_dw_init(dev);
424 	if (error != 0)
425 		goto fail;
426 
427 	error = fupci_init(sc);
428 	if (error != 0)
429 		goto fail;
430 
431 	return (bus_generic_attach(dev));
432 
433 fail:
434 	/* XXX Cleanup */
435 	return (error);
436 }
437 
438 static int
439 fupci_get_link(device_t dev, bool *status)
440 {
441 	uint32_t reg;
442 
443 	reg = pci_dw_dbi_rd4(dev, FUDW_DBI_PORT_DBG1);
444 	*status = (reg & FUDW_DBI_PORT_DBG1_LINK_UP) != 0 &&
445 	    (reg & FUDW_DBI_PORT_DBG1_LINK_IN_TRAINING) == 0;
446 
447 	return (0);
448 }
449 
450 static device_method_t fupci_methods[] = {
451 	/* Device interface */
452 	DEVMETHOD(device_probe,			fupci_probe),
453 	DEVMETHOD(device_attach,		fupci_attach),
454 
455 	/* PCI DW interface  */
456 	DEVMETHOD(pci_dw_get_link,		fupci_get_link),
457 
458 	DEVMETHOD_END
459 };
460 
461 DEFINE_CLASS_1(pcib, fupci_driver, fupci_methods,
462     sizeof(struct fupci_softc), pci_dw_driver);
463 DRIVER_MODULE(fu740_pci_dw, simplebus, fupci_driver, NULL, NULL);
464