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