1/*-
2 * Copyright (c) 2016 Jared McNeill <jmcneill@invisible.ca>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
19 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
21 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
22 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31
32#include <sys/param.h>
33#include <sys/systm.h>
34#include <sys/bus.h>
35#include <sys/kernel.h>
36#include <sys/module.h>
37#include <machine/bus.h>
38
39#include <dev/uart/uart.h>
40#include <dev/uart/uart_bus.h>
41#include <dev/uart/uart_cpu_fdt.h>
42#include <dev/uart/uart_dev_ns8250.h>
43
44#include <dev/ofw/ofw_bus.h>
45#include <dev/ofw/ofw_bus_subr.h>
46
47#ifdef EXT_RESOURCES
48#include <dev/extres/clk/clk.h>
49#include <dev/extres/hwreset/hwreset.h>
50#endif
51
52#include "uart_if.h"
53
54struct snps_softc {
55	struct ns8250_softc	ns8250;
56
57#ifdef EXT_RESOURCES
58	clk_t			baudclk;
59	clk_t			apb_pclk;
60	hwreset_t		reset;
61#endif
62};
63
64/*
65 * To use early printf on 64 bits Allwinner SoC, add to kernel config
66 * options SOCDEV_PA=0x0
67 * options SOCDEV_VA=0x40000000
68 * options EARLY_PRINTF
69 *
70 * To use early printf on 32 bits Allwinner SoC, add to kernel config
71 * options SOCDEV_PA=0x01C00000
72 * options SOCDEV_VA=0x10000000
73 * options EARLY_PRINTF
74 *
75 * remove the if 0
76*/
77#if 0
78#ifdef EARLY_PRINTF
79static void
80uart_snps_early_putc(int c)
81{
82	volatile uint32_t *stat;
83	volatile uint32_t *tx;
84
85#ifdef ALLWINNER_64
86	stat = (uint32_t *) (SOCDEV_VA + 0x1C2807C);
87	tx = (uint32_t *) (SOCDEV_VA + 0x1C28000);
88#endif
89#ifdef ALLWINNER_32
90	stat = (uint32_t *) (SOCDEV_VA + 0x2807C);
91	tx = (uint32_t *) (SOCDEV_VA + 0x28000);
92#endif
93
94	while ((*stat & (1 << 2)) == 0)
95		continue;
96	*tx = c;
97}
98early_putc_t *early_putc = uart_snps_early_putc;
99#endif /* EARLY_PRINTF */
100#endif
101
102static kobj_method_t snps_methods[] = {
103	KOBJMETHOD(uart_probe,		ns8250_bus_probe),
104	KOBJMETHOD(uart_attach,		ns8250_bus_attach),
105	KOBJMETHOD(uart_detach,		ns8250_bus_detach),
106	KOBJMETHOD(uart_flush,		ns8250_bus_flush),
107	KOBJMETHOD(uart_getsig,		ns8250_bus_getsig),
108	KOBJMETHOD(uart_ioctl,		ns8250_bus_ioctl),
109	KOBJMETHOD(uart_ipend,		ns8250_bus_ipend),
110	KOBJMETHOD(uart_param,		ns8250_bus_param),
111	KOBJMETHOD(uart_receive,	ns8250_bus_receive),
112	KOBJMETHOD(uart_setsig,		ns8250_bus_setsig),
113	KOBJMETHOD(uart_transmit,	ns8250_bus_transmit),
114	KOBJMETHOD(uart_grab,		ns8250_bus_grab),
115	KOBJMETHOD(uart_ungrab,		ns8250_bus_ungrab),
116	KOBJMETHOD_END
117};
118
119struct uart_class uart_snps_class = {
120	"snps",
121	snps_methods,
122	sizeof(struct snps_softc),
123	.uc_ops = &uart_ns8250_ops,
124	.uc_range = 8,
125	.uc_rclk = 0,
126};
127
128static struct ofw_compat_data compat_data[] = {
129	{ "snps,dw-apb-uart",		(uintptr_t)&uart_snps_class },
130	{ "marvell,armada-38x-uart",	(uintptr_t)&uart_snps_class },
131	{ NULL,				(uintptr_t)NULL }
132};
133UART_FDT_CLASS(compat_data);
134
135#ifdef EXT_RESOURCES
136static int
137snps_get_clocks(device_t dev, clk_t *baudclk, clk_t *apb_pclk)
138{
139
140	*baudclk = NULL;
141	*apb_pclk = NULL;
142
143	/* Baud clock is either named "baudclk", or there is a single
144	 * unnamed clock.
145	 */
146	if (clk_get_by_ofw_name(dev, 0, "baudclk", baudclk) != 0 &&
147	    clk_get_by_ofw_index(dev, 0, 0, baudclk) != 0)
148		return (ENOENT);
149
150	/* APB peripheral clock is optional */
151	(void)clk_get_by_ofw_name(dev, 0, "apb_pclk", apb_pclk);
152
153	return (0);
154}
155#endif
156
157static int
158snps_probe(device_t dev)
159{
160	struct snps_softc *sc;
161	struct uart_class *uart_class;
162	phandle_t node;
163	uint32_t shift, iowidth, clock;
164	uint64_t freq;
165	int error;
166#ifdef EXT_RESOURCES
167	clk_t baudclk, apb_pclk;
168	hwreset_t reset;
169#endif
170
171	if (!ofw_bus_status_okay(dev))
172		return (ENXIO);
173
174	uart_class = (struct uart_class *)ofw_bus_search_compatible(dev,
175	    compat_data)->ocd_data;
176	if (uart_class == NULL)
177		return (ENXIO);
178
179	freq = 0;
180	sc = device_get_softc(dev);
181	sc->ns8250.base.sc_class = uart_class;
182
183	node = ofw_bus_get_node(dev);
184	if (OF_getencprop(node, "reg-shift", &shift, sizeof(shift)) <= 0)
185		shift = 0;
186	if (OF_getencprop(node, "reg-io-width", &iowidth, sizeof(iowidth)) <= 0)
187		iowidth = 1;
188	if (OF_getencprop(node, "clock-frequency", &clock, sizeof(clock)) <= 0)
189		clock = 0;
190
191#ifdef EXT_RESOURCES
192	if (hwreset_get_by_ofw_idx(dev, 0, 0, &reset) == 0) {
193		error = hwreset_deassert(reset);
194		if (error != 0) {
195			device_printf(dev, "cannot de-assert reset\n");
196			return (error);
197		}
198	}
199
200	if (snps_get_clocks(dev, &baudclk, &apb_pclk) == 0) {
201		error = clk_enable(baudclk);
202		if (error != 0) {
203			device_printf(dev, "cannot enable baud clock\n");
204			return (error);
205		}
206		if (apb_pclk != NULL) {
207			error = clk_enable(apb_pclk);
208			if (error != 0) {
209				device_printf(dev,
210				    "cannot enable peripheral clock\n");
211				return (error);
212			}
213		}
214
215		if (clock == 0) {
216			error = clk_get_freq(baudclk, &freq);
217			if (error != 0) {
218				device_printf(dev, "cannot get frequency\n");
219				return (error);
220			}
221			clock = (uint32_t)freq;
222		}
223	}
224#endif
225
226	if (bootverbose && clock == 0)
227		device_printf(dev, "could not determine frequency\n");
228
229	error = uart_bus_probe(dev, (int)shift, (int)iowidth, (int)clock, 0, 0, UART_F_BUSY_DETECT);
230	if (error != 0)
231		return (error);
232
233#ifdef EXT_RESOURCES
234	/* XXX uart_bus_probe has changed the softc, so refresh it */
235	sc = device_get_softc(dev);
236
237	/* Store clock and reset handles for detach */
238	sc->baudclk = baudclk;
239	sc->apb_pclk = apb_pclk;
240	sc->reset = reset;
241#endif
242
243	return (0);
244}
245
246static int
247snps_detach(device_t dev)
248{
249#ifdef EXT_RESOURCES
250	struct snps_softc *sc;
251	clk_t baudclk, apb_pclk;
252	hwreset_t reset;
253#endif
254	int error;
255
256#ifdef EXT_RESOURCES
257	sc = device_get_softc(dev);
258	baudclk = sc->baudclk;
259	apb_pclk = sc->apb_pclk;
260	reset = sc->reset;
261#endif
262
263	error = uart_bus_detach(dev);
264	if (error != 0)
265		return (error);
266
267#ifdef EXT_RESOURCES
268	if (reset != NULL) {
269		error = hwreset_assert(reset);
270		if (error != 0) {
271			device_printf(dev, "cannot assert reset\n");
272			return (error);
273		}
274		hwreset_release(reset);
275	}
276	if (apb_pclk != NULL) {
277		error = clk_release(apb_pclk);
278		if (error != 0) {
279			device_printf(dev, "cannot release peripheral clock\n");
280			return (error);
281		}
282	}
283	if (baudclk != NULL) {
284		error = clk_release(baudclk);
285		if (error != 0) {
286			device_printf(dev, "cannot release baud clock\n");
287			return (error);
288		}
289	}
290#endif
291
292	return (0);
293}
294
295static device_method_t snps_bus_methods[] = {
296	/* Device interface */
297	DEVMETHOD(device_probe,		snps_probe),
298	DEVMETHOD(device_attach,	uart_bus_attach),
299	DEVMETHOD(device_detach, 	snps_detach),
300	DEVMETHOD_END
301};
302
303static driver_t snps_uart_driver = {
304	uart_driver_name,
305	snps_bus_methods,
306	sizeof(struct snps_softc)
307};
308
309DRIVER_MODULE(uart_snps, simplebus, snps_uart_driver, uart_devclass, 0, 0);
310