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 #include <dev/extres/clk/clk.h>
47 #include <dev/extres/hwreset/hwreset.h>
48
49 #include "uart_if.h"
50
51 struct snps_softc {
52 struct ns8250_softc ns8250;
53
54 clk_t baudclk;
55 clk_t apb_pclk;
56 hwreset_t reset;
57 };
58
59 /*
60 * To use early printf on 64 bits Allwinner SoC, add to kernel config
61 * options SOCDEV_PA=0x0
62 * options SOCDEV_VA=0x40000000
63 * options EARLY_PRINTF
64 *
65 * To use early printf on 32 bits Allwinner SoC, add to kernel config
66 * options SOCDEV_PA=0x01C00000
67 * options SOCDEV_VA=0x10000000
68 * options EARLY_PRINTF
69 *
70 * remove the if 0
71 */
72 #if 0
73 #ifdef EARLY_PRINTF
74 static void
75 uart_snps_early_putc(int c)
76 {
77 volatile uint32_t *stat;
78 volatile uint32_t *tx;
79
80 #ifdef ALLWINNER_64
81 stat = (uint32_t *) (SOCDEV_VA + 0x1C2807C);
82 tx = (uint32_t *) (SOCDEV_VA + 0x1C28000);
83 #endif
84 #ifdef ALLWINNER_32
85 stat = (uint32_t *) (SOCDEV_VA + 0x2807C);
86 tx = (uint32_t *) (SOCDEV_VA + 0x28000);
87 #endif
88
89 while ((*stat & (1 << 2)) == 0)
90 continue;
91 *tx = c;
92 }
93 early_putc_t *early_putc = uart_snps_early_putc;
94 #endif /* EARLY_PRINTF */
95 #endif
96
97 static kobj_method_t snps_methods[] = {
98 KOBJMETHOD(uart_probe, ns8250_bus_probe),
99 KOBJMETHOD(uart_attach, ns8250_bus_attach),
100 KOBJMETHOD(uart_detach, ns8250_bus_detach),
101 KOBJMETHOD(uart_flush, ns8250_bus_flush),
102 KOBJMETHOD(uart_getsig, ns8250_bus_getsig),
103 KOBJMETHOD(uart_ioctl, ns8250_bus_ioctl),
104 KOBJMETHOD(uart_ipend, ns8250_bus_ipend),
105 KOBJMETHOD(uart_param, ns8250_bus_param),
106 KOBJMETHOD(uart_receive, ns8250_bus_receive),
107 KOBJMETHOD(uart_setsig, ns8250_bus_setsig),
108 KOBJMETHOD(uart_transmit, ns8250_bus_transmit),
109 KOBJMETHOD(uart_grab, ns8250_bus_grab),
110 KOBJMETHOD(uart_ungrab, ns8250_bus_ungrab),
111 KOBJMETHOD_END
112 };
113
114 struct uart_class uart_snps_class = {
115 "snps",
116 snps_methods,
117 sizeof(struct snps_softc),
118 .uc_ops = &uart_ns8250_ops,
119 .uc_range = 8,
120 .uc_rclk = 0,
121 };
122
123 static struct ofw_compat_data compat_data[] = {
124 { "snps,dw-apb-uart", (uintptr_t)&uart_snps_class },
125 { "marvell,armada-38x-uart", (uintptr_t)&uart_snps_class },
126 { NULL, (uintptr_t)NULL }
127 };
128 UART_FDT_CLASS(compat_data);
129
130 static int
131 snps_get_clocks(device_t dev, clk_t *baudclk, clk_t *apb_pclk)
132 {
133
134 *baudclk = NULL;
135 *apb_pclk = NULL;
136
137 /* Baud clock is either named "baudclk", or there is a single
138 * unnamed clock.
139 */
140 if (clk_get_by_ofw_name(dev, 0, "baudclk", baudclk) != 0 &&
141 clk_get_by_ofw_index(dev, 0, 0, baudclk) != 0)
142 return (ENOENT);
143
144 /* APB peripheral clock is optional */
145 (void)clk_get_by_ofw_name(dev, 0, "apb_pclk", apb_pclk);
146
147 return (0);
148 }
149
150 static int
151 snps_probe(device_t dev)
152 {
153 struct snps_softc *sc;
154 struct uart_class *uart_class;
155 phandle_t node;
156 uint32_t shift, iowidth, clock;
157 uint64_t freq;
158 int error;
159 clk_t baudclk, apb_pclk;
160 hwreset_t reset;
161
162 if (!ofw_bus_status_okay(dev))
163 return (ENXIO);
164
165 uart_class = (struct uart_class *)ofw_bus_search_compatible(dev,
166 compat_data)->ocd_data;
167 if (uart_class == NULL)
168 return (ENXIO);
169
170 freq = 0;
171 sc = device_get_softc(dev);
172 sc->ns8250.base.sc_class = uart_class;
173
174 node = ofw_bus_get_node(dev);
175 if (OF_getencprop(node, "reg-shift", &shift, sizeof(shift)) <= 0)
176 shift = 0;
177 if (OF_getencprop(node, "reg-io-width", &iowidth, sizeof(iowidth)) <= 0)
178 iowidth = 1;
179 if (OF_getencprop(node, "clock-frequency", &clock, sizeof(clock)) <= 0)
180 clock = 0;
181
182 if (hwreset_get_by_ofw_idx(dev, 0, 0, &reset) == 0) {
183 error = hwreset_deassert(reset);
184 if (error != 0) {
185 device_printf(dev, "cannot de-assert reset\n");
186 return (error);
187 }
188 }
189
190 if (snps_get_clocks(dev, &baudclk, &apb_pclk) == 0) {
191 error = clk_enable(baudclk);
192 if (error != 0) {
193 device_printf(dev, "cannot enable baud clock\n");
194 return (error);
195 }
196 if (apb_pclk != NULL) {
197 error = clk_enable(apb_pclk);
198 if (error != 0) {
199 device_printf(dev,
200 "cannot enable peripheral clock\n");
201 return (error);
202 }
203 }
204
205 if (clock == 0) {
206 error = clk_get_freq(baudclk, &freq);
207 if (error != 0) {
208 device_printf(dev, "cannot get frequency\n");
209 return (error);
210 }
211 clock = (uint32_t)freq;
212 }
213 }
214
215 if (bootverbose && clock == 0)
216 device_printf(dev, "could not determine frequency\n");
217
218 error = uart_bus_probe(dev, (int)shift, (int)iowidth, (int)clock, 0, 0, UART_F_BUSY_DETECT);
219 if (error != 0)
220 return (error);
221
222 /* XXX uart_bus_probe has changed the softc, so refresh it */
223 sc = device_get_softc(dev);
224
225 /* Store clock and reset handles for detach */
226 sc->baudclk = baudclk;
227 sc->apb_pclk = apb_pclk;
228 sc->reset = reset;
229
230 return (0);
231 }
232
233 static int
234 snps_detach(device_t dev)
235 {
236 struct snps_softc *sc;
237 clk_t baudclk, apb_pclk;
238 hwreset_t reset;
239 int error;
240
241 sc = device_get_softc(dev);
242 baudclk = sc->baudclk;
243 apb_pclk = sc->apb_pclk;
244 reset = sc->reset;
245
246 error = uart_bus_detach(dev);
247 if (error != 0)
248 return (error);
249
250 if (reset != NULL) {
251 error = hwreset_assert(reset);
252 if (error != 0) {
253 device_printf(dev, "cannot assert reset\n");
254 return (error);
255 }
256 hwreset_release(reset);
257 }
258 if (apb_pclk != NULL) {
259 error = clk_release(apb_pclk);
260 if (error != 0) {
261 device_printf(dev, "cannot release peripheral clock\n");
262 return (error);
263 }
264 }
265 if (baudclk != NULL) {
266 error = clk_release(baudclk);
267 if (error != 0) {
268 device_printf(dev, "cannot release baud clock\n");
269 return (error);
270 }
271 }
272
273 return (0);
274 }
275
276 static device_method_t snps_bus_methods[] = {
277 /* Device interface */
278 DEVMETHOD(device_probe, snps_probe),
279 DEVMETHOD(device_attach, uart_bus_attach),
280 DEVMETHOD(device_detach, snps_detach),
281 DEVMETHOD_END
282 };
283
284 static driver_t snps_uart_driver = {
285 uart_driver_name,
286 snps_bus_methods,
287 sizeof(struct snps_softc)
288 };
289
290 DRIVER_MODULE(uart_snps, simplebus, snps_uart_driver, uart_devclass, 0, 0);
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