1 /*-
2 * Copyright (c) 2016 Jared McNeill <[email protected]>
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
26 #include <sys/cdefs.h>
27 #include <sys/param.h>
28 #include <sys/systm.h>
29 #include <sys/bus.h>
30 #include <sys/kernel.h>
31 #include <sys/module.h>
32 #include <machine/bus.h>
33
34 #include <dev/uart/uart.h>
35 #include <dev/uart/uart_bus.h>
36 #include <dev/uart/uart_cpu_fdt.h>
37 #include <dev/uart/uart_dev_ns8250.h>
38
39 #include <dev/ofw/ofw_bus.h>
40 #include <dev/ofw/ofw_bus_subr.h>
41
42 #include <dev/extres/clk/clk.h>
43 #include <dev/extres/hwreset/hwreset.h>
44
45 #include "uart_if.h"
46
47 struct snps_softc {
48 struct ns8250_softc ns8250;
49
50 clk_t baudclk;
51 clk_t apb_pclk;
52 hwreset_t reset;
53 };
54
55 /*
56 * To use early printf on 64 bits Allwinner SoC, add to kernel config
57 * options SOCDEV_PA=0x0
58 * options SOCDEV_VA=0x40000000
59 * options EARLY_PRINTF
60 *
61 * To use early printf on 32 bits Allwinner SoC, add to kernel config
62 * options SOCDEV_PA=0x01C00000
63 * options SOCDEV_VA=0x10000000
64 * options EARLY_PRINTF
65 *
66 * remove the if 0
67 */
68 #if 0
69 #ifdef EARLY_PRINTF
70 static void
71 uart_snps_early_putc(int c)
72 {
73 volatile uint32_t *stat;
74 volatile uint32_t *tx;
75
76 #ifdef ALLWINNER_64
77 stat = (uint32_t *) (SOCDEV_VA + 0x1C2807C);
78 tx = (uint32_t *) (SOCDEV_VA + 0x1C28000);
79 #endif
80 #ifdef ALLWINNER_32
81 stat = (uint32_t *) (SOCDEV_VA + 0x2807C);
82 tx = (uint32_t *) (SOCDEV_VA + 0x28000);
83 #endif
84
85 while ((*stat & (1 << 2)) == 0)
86 continue;
87 *tx = c;
88 }
89 early_putc_t *early_putc = uart_snps_early_putc;
90 #endif /* EARLY_PRINTF */
91 #endif
92
93 static kobj_method_t snps_methods[] = {
94 KOBJMETHOD(uart_probe, ns8250_bus_probe),
95 KOBJMETHOD(uart_attach, ns8250_bus_attach),
96 KOBJMETHOD(uart_detach, ns8250_bus_detach),
97 KOBJMETHOD(uart_flush, ns8250_bus_flush),
98 KOBJMETHOD(uart_getsig, ns8250_bus_getsig),
99 KOBJMETHOD(uart_ioctl, ns8250_bus_ioctl),
100 KOBJMETHOD(uart_ipend, ns8250_bus_ipend),
101 KOBJMETHOD(uart_param, ns8250_bus_param),
102 KOBJMETHOD(uart_receive, ns8250_bus_receive),
103 KOBJMETHOD(uart_setsig, ns8250_bus_setsig),
104 KOBJMETHOD(uart_transmit, ns8250_bus_transmit),
105 KOBJMETHOD(uart_txbusy, ns8250_bus_txbusy),
106 KOBJMETHOD(uart_grab, ns8250_bus_grab),
107 KOBJMETHOD(uart_ungrab, ns8250_bus_ungrab),
108 KOBJMETHOD_END
109 };
110
111 struct uart_class uart_snps_class = {
112 "snps",
113 snps_methods,
114 sizeof(struct snps_softc),
115 .uc_ops = &uart_ns8250_ops,
116 .uc_range = 8,
117 .uc_rclk = 0,
118 };
119
120 static struct ofw_compat_data compat_data[] = {
121 { "snps,dw-apb-uart", (uintptr_t)&uart_snps_class },
122 { "marvell,armada-38x-uart", (uintptr_t)&uart_snps_class },
123 { NULL, (uintptr_t)NULL }
124 };
125 UART_FDT_CLASS(compat_data);
126
127 static int
snps_get_clocks(device_t dev,clk_t * baudclk,clk_t * apb_pclk)128 snps_get_clocks(device_t dev, clk_t *baudclk, clk_t *apb_pclk)
129 {
130
131 *baudclk = NULL;
132 *apb_pclk = NULL;
133
134 /* Baud clock is either named "baudclk", or there is a single
135 * unnamed clock.
136 */
137 if (clk_get_by_ofw_name(dev, 0, "baudclk", baudclk) != 0 &&
138 clk_get_by_ofw_index(dev, 0, 0, baudclk) != 0)
139 return (ENOENT);
140
141 /* APB peripheral clock is optional */
142 (void)clk_get_by_ofw_name(dev, 0, "apb_pclk", apb_pclk);
143
144 return (0);
145 }
146
147 static int
snps_probe(device_t dev)148 snps_probe(device_t dev)
149 {
150 struct snps_softc *sc;
151 struct uart_class *uart_class;
152 phandle_t node;
153 uint32_t shift, iowidth, clock;
154 uint64_t freq;
155 int error;
156 clk_t baudclk, apb_pclk;
157 hwreset_t reset;
158
159 if (!ofw_bus_status_okay(dev))
160 return (ENXIO);
161
162 uart_class = (struct uart_class *)ofw_bus_search_compatible(dev,
163 compat_data)->ocd_data;
164 if (uart_class == NULL)
165 return (ENXIO);
166
167 freq = 0;
168 sc = device_get_softc(dev);
169 sc->ns8250.base.sc_class = uart_class;
170
171 node = ofw_bus_get_node(dev);
172 if (OF_getencprop(node, "reg-shift", &shift, sizeof(shift)) <= 0)
173 shift = 0;
174 if (OF_getencprop(node, "reg-io-width", &iowidth, sizeof(iowidth)) <= 0)
175 iowidth = 1;
176 if (OF_getencprop(node, "clock-frequency", &clock, sizeof(clock)) <= 0)
177 clock = 0;
178
179 if (hwreset_get_by_ofw_idx(dev, 0, 0, &reset) == 0) {
180 error = hwreset_deassert(reset);
181 if (error != 0) {
182 device_printf(dev, "cannot de-assert reset\n");
183 return (error);
184 }
185 }
186
187 if (snps_get_clocks(dev, &baudclk, &apb_pclk) == 0) {
188 error = clk_enable(baudclk);
189 if (error != 0) {
190 device_printf(dev, "cannot enable baud clock\n");
191 return (error);
192 }
193 if (apb_pclk != NULL) {
194 error = clk_enable(apb_pclk);
195 if (error != 0) {
196 device_printf(dev,
197 "cannot enable peripheral clock\n");
198 return (error);
199 }
200 }
201
202 if (clock == 0) {
203 error = clk_get_freq(baudclk, &freq);
204 if (error != 0) {
205 device_printf(dev, "cannot get frequency\n");
206 return (error);
207 }
208 clock = (uint32_t)freq;
209 }
210 }
211
212 if (bootverbose && clock == 0)
213 device_printf(dev, "could not determine frequency\n");
214
215 error = uart_bus_probe(dev, (int)shift, (int)iowidth, (int)clock, 0, 0, UART_F_BUSY_DETECT);
216 if (error > 0)
217 return (error);
218
219 /* XXX uart_bus_probe has changed the softc, so refresh it */
220 sc = device_get_softc(dev);
221
222 /* Store clock and reset handles for detach */
223 sc->baudclk = baudclk;
224 sc->apb_pclk = apb_pclk;
225 sc->reset = reset;
226
227 return (BUS_PROBE_VENDOR);
228 }
229
230 static int
snps_detach(device_t dev)231 snps_detach(device_t dev)
232 {
233 struct snps_softc *sc;
234 clk_t baudclk, apb_pclk;
235 hwreset_t reset;
236 int error;
237
238 sc = device_get_softc(dev);
239 baudclk = sc->baudclk;
240 apb_pclk = sc->apb_pclk;
241 reset = sc->reset;
242
243 error = uart_bus_detach(dev);
244 if (error != 0)
245 return (error);
246
247 if (reset != NULL) {
248 error = hwreset_assert(reset);
249 if (error != 0) {
250 device_printf(dev, "cannot assert reset\n");
251 return (error);
252 }
253 hwreset_release(reset);
254 }
255 if (apb_pclk != NULL) {
256 error = clk_release(apb_pclk);
257 if (error != 0) {
258 device_printf(dev, "cannot release peripheral clock\n");
259 return (error);
260 }
261 }
262 if (baudclk != NULL) {
263 error = clk_release(baudclk);
264 if (error != 0) {
265 device_printf(dev, "cannot release baud clock\n");
266 return (error);
267 }
268 }
269
270 return (0);
271 }
272
273 static device_method_t snps_bus_methods[] = {
274 /* Device interface */
275 DEVMETHOD(device_probe, snps_probe),
276 DEVMETHOD(device_attach, uart_bus_attach),
277 DEVMETHOD(device_detach, snps_detach),
278 DEVMETHOD_END
279 };
280
281 static driver_t snps_uart_driver = {
282 uart_driver_name,
283 snps_bus_methods,
284 sizeof(struct snps_softc)
285 };
286
287 DRIVER_MODULE(uart_snps, simplebus, snps_uart_driver, 0, 0);
288