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
26 #include <sys/param.h>
27 #include <sys/systm.h>
28 #include <sys/bus.h>
29 #include <sys/kernel.h>
30 #include <sys/module.h>
31 #include <machine/bus.h>
32
33 #include <dev/uart/uart.h>
34 #include <dev/uart/uart_bus.h>
35 #include <dev/uart/uart_cpu_fdt.h>
36 #include <dev/uart/uart_dev_ns8250.h>
37
38 #include <dev/ofw/ofw_bus.h>
39 #include <dev/ofw/ofw_bus_subr.h>
40
41 #include <dev/clk/clk.h>
42 #include <dev/hwreset/hwreset.h>
43
44 #include "uart_if.h"
45
46 struct snps_softc {
47 struct ns8250_softc ns8250;
48
49 clk_t baudclk;
50 clk_t apb_pclk;
51 hwreset_t reset;
52 };
53
54 /*
55 * To use early printf on 64 bits Allwinner SoC, add to kernel config
56 * options SOCDEV_PA=0x0
57 * options EARLY_PRINTF=snps
58 *
59 * To use early printf on 32 bits Allwinner SoC, add to kernel config
60 * options SOCDEV_PA=0x01C00000
61 * options SOCDEV_VA=0x10000000
62 * options EARLY_PRINTF=snps
63 *
64 * remove the if 0
65 */
66 #if CHECK_EARLY_PRINTF(snps)
67 static void
uart_snps_early_putc(int c)68 uart_snps_early_putc(int c)
69 {
70 volatile uint32_t *stat;
71 volatile uint32_t *tx;
72
73 #ifdef ALLWINNER_64
74 stat = (uint32_t *) (socdev_va + 0x1C2807C);
75 tx = (uint32_t *) (socdev_va + 0x1C28000);
76 #endif
77 #ifdef ALLWINNER_32
78 stat = (uint32_t *) (socdev_va + 0x2807C);
79 tx = (uint32_t *) (socdev_va + 0x28000);
80 #endif
81
82 while ((*stat & (1 << 2)) == 0)
83 continue;
84 *tx = c;
85 }
86 early_putc_t *early_putc = uart_snps_early_putc;
87 #endif /* CHECK_EARLY_PRINTF */
88
89 static kobj_method_t snps_methods[] = {
90 KOBJMETHOD(uart_probe, ns8250_bus_probe),
91 KOBJMETHOD(uart_attach, ns8250_bus_attach),
92 KOBJMETHOD(uart_detach, ns8250_bus_detach),
93 KOBJMETHOD(uart_flush, ns8250_bus_flush),
94 KOBJMETHOD(uart_getsig, ns8250_bus_getsig),
95 KOBJMETHOD(uart_ioctl, ns8250_bus_ioctl),
96 KOBJMETHOD(uart_ipend, ns8250_bus_ipend),
97 KOBJMETHOD(uart_param, ns8250_bus_param),
98 KOBJMETHOD(uart_receive, ns8250_bus_receive),
99 KOBJMETHOD(uart_setsig, ns8250_bus_setsig),
100 KOBJMETHOD(uart_transmit, ns8250_bus_transmit),
101 KOBJMETHOD(uart_txbusy, ns8250_bus_txbusy),
102 KOBJMETHOD(uart_grab, ns8250_bus_grab),
103 KOBJMETHOD(uart_ungrab, ns8250_bus_ungrab),
104 KOBJMETHOD_END
105 };
106
107 struct uart_class uart_snps_class = {
108 "snps",
109 snps_methods,
110 sizeof(struct snps_softc),
111 .uc_ops = &uart_ns8250_ops,
112 .uc_range = 8,
113 .uc_rclk = 0,
114 };
115
116 static struct ofw_compat_data compat_data[] = {
117 { "snps,dw-apb-uart", (uintptr_t)&uart_snps_class },
118 { "marvell,armada-38x-uart", (uintptr_t)&uart_snps_class },
119 { NULL, (uintptr_t)NULL }
120 };
121 UART_FDT_CLASS(compat_data);
122
123 static int
snps_get_clocks(device_t dev,clk_t * baudclk,clk_t * apb_pclk)124 snps_get_clocks(device_t dev, clk_t *baudclk, clk_t *apb_pclk)
125 {
126
127 *baudclk = NULL;
128 *apb_pclk = NULL;
129
130 /* Baud clock is either named "baudclk", or there is a single
131 * unnamed clock.
132 */
133 if (clk_get_by_ofw_name(dev, 0, "baudclk", baudclk) != 0 &&
134 clk_get_by_ofw_index(dev, 0, 0, baudclk) != 0)
135 return (ENOENT);
136
137 /* APB peripheral clock is optional */
138 (void)clk_get_by_ofw_name(dev, 0, "apb_pclk", apb_pclk);
139
140 return (0);
141 }
142
143 static int
snps_probe(device_t dev)144 snps_probe(device_t dev)
145 {
146 struct snps_softc *sc;
147 struct uart_class *uart_class;
148 phandle_t node;
149 uint32_t shift, iowidth, clock;
150 uint64_t freq;
151 int error;
152 clk_t baudclk, apb_pclk;
153 hwreset_t reset;
154
155 if (!ofw_bus_status_okay(dev))
156 return (ENXIO);
157
158 uart_class = (struct uart_class *)ofw_bus_search_compatible(dev,
159 compat_data)->ocd_data;
160 if (uart_class == NULL)
161 return (ENXIO);
162
163 freq = 0;
164 sc = device_get_softc(dev);
165 sc->ns8250.base.sc_class = uart_class;
166
167 node = ofw_bus_get_node(dev);
168 if (OF_getencprop(node, "reg-shift", &shift, sizeof(shift)) <= 0)
169 shift = 0;
170 if (OF_getencprop(node, "reg-io-width", &iowidth, sizeof(iowidth)) <= 0)
171 iowidth = 1;
172 if (OF_getencprop(node, "clock-frequency", &clock, sizeof(clock)) <= 0)
173 clock = 0;
174
175 if (hwreset_get_by_ofw_idx(dev, 0, 0, &reset) == 0) {
176 error = hwreset_deassert(reset);
177 if (error != 0) {
178 device_printf(dev, "cannot de-assert reset\n");
179 return (error);
180 }
181 }
182
183 if (snps_get_clocks(dev, &baudclk, &apb_pclk) == 0) {
184 error = clk_enable(baudclk);
185 if (error != 0) {
186 device_printf(dev, "cannot enable baud clock\n");
187 return (error);
188 }
189 if (apb_pclk != NULL) {
190 error = clk_enable(apb_pclk);
191 if (error != 0) {
192 device_printf(dev,
193 "cannot enable peripheral clock\n");
194 return (error);
195 }
196 }
197
198 if (clock == 0) {
199 error = clk_get_freq(baudclk, &freq);
200 if (error != 0) {
201 device_printf(dev, "cannot get frequency\n");
202 return (error);
203 }
204 clock = (uint32_t)freq;
205 }
206 }
207
208 if (bootverbose && clock == 0)
209 device_printf(dev, "could not determine frequency\n");
210
211 error = uart_bus_probe(dev, (int)shift, (int)iowidth, (int)clock, 0, 0, UART_F_BUSY_DETECT);
212 if (error > 0)
213 return (error);
214
215 /* XXX uart_bus_probe has changed the softc, so refresh it */
216 sc = device_get_softc(dev);
217
218 /* Store clock and reset handles for detach */
219 sc->baudclk = baudclk;
220 sc->apb_pclk = apb_pclk;
221 sc->reset = reset;
222
223 return (BUS_PROBE_VENDOR);
224 }
225
226 static int
snps_attach(device_t dev)227 snps_attach(device_t dev)
228 {
229 phandle_t node;
230 int ret;
231
232 ret = uart_bus_attach(dev);
233 if (ret == 0) {
234 node = ofw_bus_get_node(dev);
235 /* Set up phandle to dev mapping */
236 OF_device_register_xref(OF_xref_from_node(node), dev);
237 }
238
239 return (ret);
240 }
241
242 static int
snps_detach(device_t dev)243 snps_detach(device_t dev)
244 {
245 struct snps_softc *sc;
246 clk_t baudclk, apb_pclk;
247 hwreset_t reset;
248 int error;
249
250 sc = device_get_softc(dev);
251 baudclk = sc->baudclk;
252 apb_pclk = sc->apb_pclk;
253 reset = sc->reset;
254
255 error = uart_bus_detach(dev);
256 if (error != 0)
257 return (error);
258
259 if (reset != NULL) {
260 error = hwreset_assert(reset);
261 if (error != 0) {
262 device_printf(dev, "cannot assert reset\n");
263 return (error);
264 }
265 hwreset_release(reset);
266 }
267 if (apb_pclk != NULL) {
268 error = clk_release(apb_pclk);
269 if (error != 0) {
270 device_printf(dev, "cannot release peripheral clock\n");
271 return (error);
272 }
273 }
274 if (baudclk != NULL) {
275 error = clk_release(baudclk);
276 if (error != 0) {
277 device_printf(dev, "cannot release baud clock\n");
278 return (error);
279 }
280 }
281
282 return (0);
283 }
284
285 static device_method_t snps_bus_methods[] = {
286 /* Device interface */
287 DEVMETHOD(device_probe, snps_probe),
288 DEVMETHOD(device_attach, snps_attach),
289 DEVMETHOD(device_detach, snps_detach),
290 DEVMETHOD_END
291 };
292
293 static driver_t snps_uart_driver = {
294 uart_driver_name,
295 snps_bus_methods,
296 sizeof(struct snps_softc)
297 };
298
299 DRIVER_MODULE(uart_snps, simplebus, snps_uart_driver, 0, 0);
300