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