xref: /freebsd/sys/dev/uart/uart_dev_snps.c (revision e17f5b1d307b7b8910d67883e57a9604305906d5)
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 
53 struct 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
78 static void
79 uart_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 }
97 early_putc_t *early_putc = uart_snps_early_putc;
98 #endif /* EARLY_PRINTF */
99 #endif
100 
101 static 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 
118 struct 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 
127 static 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 };
132 UART_FDT_CLASS(compat_data);
133 
134 #ifdef EXT_RESOURCES
135 static int
136 snps_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 
156 static int
157 snps_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 
245 static int
246 snps_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 
294 static 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 
302 static driver_t snps_uart_driver = {
303 	uart_driver_name,
304 	snps_bus_methods,
305 	sizeof(struct snps_softc)
306 };
307 
308 DRIVER_MODULE(uart_snps, simplebus, snps_uart_driver, uart_devclass, 0, 0);
309