xref: /freebsd/sys/riscv/sifive/fu740_pci_dw.c (revision 315ee00f)
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 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/gpio.h>
36 #include <sys/kernel.h>
37 #include <sys/module.h>
38 #include <sys/rman.h>
39 
40 #include <machine/bus.h>
41 #include <machine/intr.h>
42 #include <machine/resource.h>
43 
44 #include <dev/extres/clk/clk.h>
45 #include <dev/extres/hwreset/hwreset.h>
46 #include <dev/gpio/gpiobusvar.h>
47 #include <dev/ofw/ofw_bus.h>
48 #include <dev/ofw/ofw_bus_subr.h>
49 #include <dev/ofw/ofw_pci.h>
50 #include <dev/ofw/ofwpci.h>
51 #include <dev/pci/pcivar.h>
52 #include <dev/pci/pcireg.h>
53 #include <dev/pci/pcib_private.h>
54 #include <dev/pci/pci_dw.h>
55 
56 #include "pcib_if.h"
57 #include "pci_dw_if.h"
58 
59 #define	FUDW_PHYS		2
60 #define	FUDW_LANES_PER_PHY	4
61 
62 #define	FUDW_MGMT_PERST_N			0x0
63 #define	FUDW_MGMT_LTSSM_EN			0x10
64 #define	FUDW_MGMT_HOLD_PHY_RST			0x18
65 #define	FUDW_MGMT_DEVICE_TYPE			0x708
66 #define	 FUDW_MGMT_DEVICE_TYPE_RC			0x4
67 #define	FUDW_MGMT_PHY_CR_PARA_REG(_n, _r)	\
68     (0x860 + (_n) * 0x40 + FUDW_MGMT_PHY_CR_PARA_##_r)
69 #define	 FUDW_MGMT_PHY_CR_PARA_ADDR			0x0
70 #define	 FUDW_MGMT_PHY_CR_PARA_READ_EN			0x10
71 #define	 FUDW_MGMT_PHY_CR_PARA_READ_DATA		0x18
72 #define	 FUDW_MGMT_PHY_CR_PARA_SEL			0x20
73 #define	 FUDW_MGMT_PHY_CR_PARA_WRITE_DATA		0x28
74 #define	 FUDW_MGMT_PHY_CR_PARA_WRITE_EN			0x30
75 #define	 FUDW_MGMT_PHY_CR_PARA_ACK			0x38
76 
77 #define	FUDW_MGMT_PHY_LANE(_n)			(0x1008 + (_n) * 0x100)
78 #define	 FUDW_MGMT_PHY_LANE_CDR_TRACK_EN		(1 << 0)
79 #define	 FUDW_MGMT_PHY_LANE_LOS_THRESH			(1 << 5)
80 #define	 FUDW_MGMT_PHY_LANE_TERM_EN			(1 << 9)
81 #define	 FUDW_MGMT_PHY_LANE_TERM_ACDC			(1 << 10)
82 #define	 FUDW_MGMT_PHY_LANE_EN				(1 << 11)
83 #define	 FUDW_MGMT_PHY_LANE_INIT					\
84     (FUDW_MGMT_PHY_LANE_CDR_TRACK_EN | FUDW_MGMT_PHY_LANE_LOS_THRESH |	\
85      FUDW_MGMT_PHY_LANE_TERM_EN | FUDW_MGMT_PHY_LANE_TERM_ACDC |	\
86      FUDW_MGMT_PHY_LANE_EN)
87 
88 #define	FUDW_DBI_PORT_DBG1			0x72c
89 #define	 FUDW_DBI_PORT_DBG1_LINK_UP			(1 << 4)
90 #define	 FUDW_DBI_PORT_DBG1_LINK_IN_TRAINING		(1 << 29)
91 
92 struct fupci_softc {
93 	struct pci_dw_softc	dw_sc;
94 	device_t		dev;
95 	struct resource		*mgmt_res;
96 	gpio_pin_t		porst_pin;
97 	gpio_pin_t		pwren_pin;
98 	clk_t			pcie_aux_clk;
99 	hwreset_t		pcie_aux_rst;
100 };
101 
102 #define	FUDW_MGMT_READ(_sc, _o)		bus_read_4((_sc)->mgmt_res, (_o))
103 #define	FUDW_MGMT_WRITE(_sc, _o, _v)	bus_write_4((_sc)->mgmt_res, (_o), (_v))
104 
105 static struct ofw_compat_data compat_data[] = {
106 	{ "sifive,fu740-pcie",	1 },
107 	{ NULL,			0 },
108 };
109 
110 /* Currently unused; included for completeness */
111 static int __unused
112 fupci_phy_read(struct fupci_softc *sc, int phy, uint32_t reg, uint32_t *val)
113 {
114 	unsigned timeout;
115 	uint32_t ack;
116 
117 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, ADDR), reg);
118 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, READ_EN), 1);
119 
120 	timeout = 10;
121 	do {
122 		ack = FUDW_MGMT_READ(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, ACK));
123 		if (ack != 0)
124 			break;
125 		DELAY(10);
126 	} while (--timeout > 0);
127 
128 	if (timeout == 0) {
129 		device_printf(sc->dev, "Timeout waiting for read ACK\n");
130 		return (ETIMEDOUT);
131 	}
132 
133 	*val = FUDW_MGMT_READ(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, READ_DATA));
134 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, READ_EN), 0);
135 
136 	timeout = 10;
137 	do {
138 		ack = FUDW_MGMT_READ(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, ACK));
139 		if (ack == 0)
140 			break;
141 		DELAY(10);
142 	} while (--timeout > 0);
143 
144 	if (timeout == 0) {
145 		device_printf(sc->dev, "Timeout waiting for read un-ACK\n");
146 		return (ETIMEDOUT);
147 	}
148 
149 	return (0);
150 }
151 
152 static int
153 fupci_phy_write(struct fupci_softc *sc, int phy, uint32_t reg, uint32_t val)
154 {
155 	unsigned timeout;
156 	uint32_t ack;
157 
158 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, ADDR), reg);
159 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, WRITE_DATA), val);
160 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, WRITE_EN), 1);
161 
162 	timeout = 10;
163 	do {
164 		ack = FUDW_MGMT_READ(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, ACK));
165 		if (ack != 0)
166 			break;
167 		DELAY(10);
168 	} while (--timeout > 0);
169 
170 	if (timeout == 0) {
171 		device_printf(sc->dev, "Timeout waiting for write ACK\n");
172 		return (ETIMEDOUT);
173 	}
174 
175 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, WRITE_EN), 0);
176 
177 	timeout = 10;
178 	do {
179 		ack = FUDW_MGMT_READ(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, ACK));
180 		if (ack == 0)
181 			break;
182 		DELAY(10);
183 	} while (--timeout > 0);
184 
185 	if (timeout == 0) {
186 		device_printf(sc->dev, "Timeout waiting for write un-ACK\n");
187 		return (ETIMEDOUT);
188 	}
189 
190 	return (0);
191 }
192 
193 static int
194 fupci_phy_init(struct fupci_softc *sc)
195 {
196 	device_t dev;
197 	int error, phy, lane;
198 
199 	dev = sc->dev;
200 
201 	/* Assert core power-on reset (active low) */
202 	error = gpio_pin_set_active(sc->porst_pin, false);
203 	if (error != 0) {
204 		device_printf(dev, "Cannot assert power-on reset: %d\n",
205 		    error);
206 		return (error);
207 	}
208 
209 	/* Assert PERST_N */
210 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PERST_N, 0);
211 
212 	/* Enable power */
213 	error = gpio_pin_set_active(sc->pwren_pin, true);
214 	if (error != 0) {
215 		device_printf(dev, "Cannot enable power: %d\n", error);
216 		return (error);
217 	}
218 
219 	/* Hold PERST for 100ms as per the PCIe spec */
220 	DELAY(100);
221 
222 	/* Deassert PERST_N */
223 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_PERST_N, 1);
224 
225 	/* Deassert core power-on reset (active low) */
226 	error = gpio_pin_set_active(sc->porst_pin, true);
227 	if (error != 0) {
228 		device_printf(dev, "Cannot deassert power-on reset: %d\n",
229 		    error);
230 		return (error);
231 	}
232 
233 	/* Enable the aux clock */
234 	error = clk_enable(sc->pcie_aux_clk);
235 	if (error != 0) {
236 		device_printf(dev, "Cannot enable aux clock: %d\n", error);
237 		return (error);
238 	}
239 
240 	/* Hold LTSSM in reset whilst initialising the PHYs */
241 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_HOLD_PHY_RST, 1);
242 
243 	/* Deassert the aux reset */
244 	error = hwreset_deassert(sc->pcie_aux_rst);
245 	if (error != 0) {
246 		device_printf(dev, "Cannot deassert aux reset: %d\n", error);
247 		return (error);
248 	}
249 
250 	/* Enable control register interface */
251 	for (phy = 0; phy < FUDW_PHYS; ++phy)
252 		FUDW_MGMT_WRITE(sc, FUDW_MGMT_PHY_CR_PARA_REG(phy, SEL), 1);
253 
254 	/* Wait for enable to take effect */
255 	DELAY(1);
256 
257 	/* Initialise lane configuration */
258 	for (phy = 0; phy < FUDW_PHYS; ++phy) {
259 		for (lane = 0; lane < FUDW_LANES_PER_PHY; ++lane)
260 			fupci_phy_write(sc, phy, FUDW_MGMT_PHY_LANE(lane),
261 			    FUDW_MGMT_PHY_LANE_INIT);
262 	}
263 
264 	/* Disable the aux clock whilst taking the LTSSM out of reset */
265 	error = clk_disable(sc->pcie_aux_clk);
266 	if (error != 0) {
267 		device_printf(dev, "Cannot disable aux clock: %d\n", error);
268 		return (error);
269 	}
270 
271 	/* Take LTSSM out of reset */
272 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_HOLD_PHY_RST, 0);
273 
274 	/* Enable the aux clock again */
275 	error = clk_enable(sc->pcie_aux_clk);
276 	if (error != 0) {
277 		device_printf(dev, "Cannot re-enable aux clock: %d\n", error);
278 		return (error);
279 	}
280 
281 	/* Put the controller in Root Complex mode */
282 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_DEVICE_TYPE, FUDW_MGMT_DEVICE_TYPE_RC);
283 
284 	return (0);
285 }
286 
287 static void
288 fupci_dbi_protect(struct fupci_softc *sc, bool protect)
289 {
290 	uint32_t reg;
291 
292 	reg = pci_dw_dbi_rd4(sc->dev, DW_MISC_CONTROL_1);
293 	if (protect)
294 		reg &= ~DBI_RO_WR_EN;
295 	else
296 		reg |= DBI_RO_WR_EN;
297 	pci_dw_dbi_wr4(sc->dev, DW_MISC_CONTROL_1, reg);
298 }
299 
300 static int
301 fupci_init(struct fupci_softc *sc)
302 {
303 	/* Enable 32-bit I/O window */
304 	fupci_dbi_protect(sc, false);
305 	pci_dw_dbi_wr2(sc->dev, PCIR_IOBASEL_1,
306 	    (PCIM_BRIO_32 << 8) | PCIM_BRIO_32);
307 	fupci_dbi_protect(sc, true);
308 
309 	/* Enable LTSSM */
310 	FUDW_MGMT_WRITE(sc, FUDW_MGMT_LTSSM_EN, 1);
311 
312 	return (0);
313 }
314 
315 static int
316 fupci_probe(device_t dev)
317 {
318 	if (!ofw_bus_status_okay(dev))
319 		return (ENXIO);
320 
321 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
322 		return (ENXIO);
323 
324 	device_set_desc(dev, "SiFive FU740 PCIe Controller");
325 
326 	return (BUS_PROBE_DEFAULT);
327 }
328 
329 static int
330 fupci_attach(device_t dev)
331 {
332 	struct fupci_softc *sc;
333 	phandle_t node;
334 	int error, rid;
335 
336 	sc = device_get_softc(dev);
337 	node = ofw_bus_get_node(dev);
338 	sc->dev = dev;
339 
340 	rid = 0;
341 	error = ofw_bus_find_string_index(node, "reg-names", "dbi", &rid);
342 	if (error != 0) {
343 		device_printf(dev, "Cannot get DBI memory: %d\n", error);
344 		goto fail;
345 	}
346 	sc->dw_sc.dbi_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
347 	    RF_ACTIVE);
348 	if (sc->dw_sc.dbi_res == NULL) {
349 		device_printf(dev, "Cannot allocate DBI memory\n");
350 		error = ENXIO;
351 		goto fail;
352 	}
353 
354 	rid = 0;
355 	error = ofw_bus_find_string_index(node, "reg-names", "mgmt", &rid);
356 	if (error != 0) {
357 		device_printf(dev, "Cannot get management space memory: %d\n",
358 		    error);
359 		goto fail;
360 	}
361 	sc->mgmt_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
362 	    RF_ACTIVE);
363 	if (sc->mgmt_res == NULL) {
364 		device_printf(dev, "Cannot allocate management space memory\n");
365 		error = ENXIO;
366 		goto fail;
367 	}
368 
369 	error = gpio_pin_get_by_ofw_property(dev, node, "reset-gpios",
370 	    &sc->porst_pin);
371 	/* Old U-Boot device tree uses perstn-gpios */
372 	if (error == ENOENT)
373 		error = gpio_pin_get_by_ofw_property(dev, node, "perstn-gpios",
374 		    &sc->porst_pin);
375 	if (error != 0) {
376 		device_printf(dev, "Cannot get power-on reset GPIO: %d\n",
377 		    error);
378 		goto fail;
379 	}
380 	error = gpio_pin_setflags(sc->porst_pin, GPIO_PIN_OUTPUT);
381 	if (error != 0) {
382 		device_printf(dev, "Cannot configure power-on reset GPIO: %d\n",
383 		    error);
384 		goto fail;
385 	}
386 
387 	error = gpio_pin_get_by_ofw_property(dev, node, "pwren-gpios",
388 	    &sc->pwren_pin);
389 	if (error != 0) {
390 		device_printf(dev, "Cannot get power enable GPIO: %d\n",
391 		    error);
392 		goto fail;
393 	}
394 	error = gpio_pin_setflags(sc->pwren_pin, GPIO_PIN_OUTPUT);
395 	if (error != 0) {
396 		device_printf(dev, "Cannot configure power enable GPIO: %d\n",
397 		    error);
398 		goto fail;
399 	}
400 
401 	error = clk_get_by_ofw_name(dev, node, "pcie_aux", &sc->pcie_aux_clk);
402 	/* Old U-Boot device tree uses pcieaux */
403 	if (error == ENOENT)
404 		error = clk_get_by_ofw_name(dev, node, "pcieaux",
405 		    &sc->pcie_aux_clk);
406 	if (error != 0) {
407 		device_printf(dev, "Cannot get aux clock: %d\n", error);
408 		goto fail;
409 	}
410 
411 	error = hwreset_get_by_ofw_idx(dev, node, 0, &sc->pcie_aux_rst);
412 	if (error != 0) {
413 		device_printf(dev, "Cannot get aux reset: %d\n", error);
414 		goto fail;
415 	}
416 
417 	error = fupci_phy_init(sc);
418 	if (error != 0)
419 		goto fail;
420 
421 	error = pci_dw_init(dev);
422 	if (error != 0)
423 		goto fail;
424 
425 	error = fupci_init(sc);
426 	if (error != 0)
427 		goto fail;
428 
429 	return (bus_generic_attach(dev));
430 
431 fail:
432 	/* XXX Cleanup */
433 	return (error);
434 }
435 
436 static int
437 fupci_get_link(device_t dev, bool *status)
438 {
439 	uint32_t reg;
440 
441 	reg = pci_dw_dbi_rd4(dev, FUDW_DBI_PORT_DBG1);
442 	*status = (reg & FUDW_DBI_PORT_DBG1_LINK_UP) != 0 &&
443 	    (reg & FUDW_DBI_PORT_DBG1_LINK_IN_TRAINING) == 0;
444 
445 	return (0);
446 }
447 
448 static device_method_t fupci_methods[] = {
449 	/* Device interface */
450 	DEVMETHOD(device_probe,			fupci_probe),
451 	DEVMETHOD(device_attach,		fupci_attach),
452 
453 	/* PCI DW interface  */
454 	DEVMETHOD(pci_dw_get_link,		fupci_get_link),
455 
456 	DEVMETHOD_END
457 };
458 
459 DEFINE_CLASS_1(pcib, fupci_driver, fupci_methods,
460     sizeof(struct fupci_softc), pci_dw_driver);
461 DRIVER_MODULE(fu740_pci_dw, simplebus, fupci_driver, NULL, NULL);
462