ssdfb_spi.c revision 1.4
1 /* $NetBSD: ssdfb_spi.c,v 1.4 2021/01/17 21:42:35 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 2019 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Tobias Nygren. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: ssdfb_spi.c,v 1.4 2021/01/17 21:42:35 thorpej Exp $"); 34 35 #include <sys/param.h> 36 #include <sys/device.h> 37 #include <sys/kernel.h> 38 #include <dev/wscons/wsdisplayvar.h> 39 #include <dev/rasops/rasops.h> 40 #include <dev/spi/spivar.h> 41 #include <dev/ic/ssdfbvar.h> 42 43 struct bs_state { 44 uint8_t *base; 45 uint8_t *cur; 46 uint8_t mask; 47 }; 48 49 struct ssdfb_spi_softc { 50 struct ssdfb_softc sc; 51 struct spi_handle *sc_sh; 52 bool sc_3wiremode; 53 }; 54 55 static int ssdfb_spi_match(device_t, cfdata_t, void *); 56 static void ssdfb_spi_attach(device_t, device_t, void *); 57 58 static int ssdfb_spi_cmd_3wire(void *, uint8_t *, size_t, bool); 59 static int ssdfb_spi_xfer_rect_3wire_ssd1322(void *, uint8_t, uint8_t, 60 uint8_t, uint8_t, uint8_t *, size_t, bool); 61 62 static int ssdfb_spi_cmd_4wire(void *, uint8_t *, size_t, bool); 63 static int ssdfb_spi_xfer_rect_4wire_ssd1322(void *, uint8_t, uint8_t, 64 uint8_t, uint8_t, uint8_t *, size_t, bool); 65 66 static void ssdfb_bitstream_init(struct bs_state *, uint8_t *); 67 static void ssdfb_bitstream_append(struct bs_state *, uint8_t, uint8_t); 68 static void ssdfb_bitstream_append_cmd(struct bs_state *, uint8_t); 69 static void ssdfb_bitstream_append_data(struct bs_state *, uint8_t *, 70 size_t); 71 static void ssdfb_bitstream_final(struct bs_state *); 72 73 CFATTACH_DECL_NEW(ssdfb_spi, sizeof(struct ssdfb_spi_softc), 74 ssdfb_spi_match, ssdfb_spi_attach, NULL, NULL); 75 76 static const struct device_compatible_entry compat_data[] = { 77 { .compat = "solomon,ssd1322" }, 78 79 { 0 } 80 }; 81 82 static int 83 ssdfb_spi_match(device_t parent, cfdata_t match, void *aux) 84 { 85 struct spi_attach_args *sa = aux; 86 int res; 87 88 res = spi_compatible_match(sa, match, compat_data); 89 if (!res) 90 return res; 91 92 /* 93 * SSD1306 and SSD1322 data sheets specify 100ns cycle time. 94 */ 95 if (spi_configure(sa->sa_handle, SPI_MODE_0, 10000000)) 96 res = 0; 97 98 return res; 99 } 100 101 static void 102 ssdfb_spi_attach(device_t parent, device_t self, void *aux) 103 { 104 struct ssdfb_spi_softc *sc = device_private(self); 105 struct cfdata *cf = device_cfdata(self); 106 struct spi_attach_args *sa = aux; 107 int flags = cf->cf_flags; 108 109 sc->sc.sc_dev = self; 110 sc->sc_sh = sa->sa_handle; 111 sc->sc.sc_cookie = (void *)sc; 112 if ((flags & SSDFB_ATTACH_FLAG_PRODUCT_MASK) == SSDFB_PRODUCT_UNKNOWN) 113 flags |= SSDFB_PRODUCT_SSD1322_GENERIC; 114 /* 115 * Note on interface modes. 116 * 117 * 3 wire mode sends 9 bit sequences over the MOSI, MSB contains 118 * the bit that determines if the lower 8 bits are command or data. 119 * 120 * 4 wire mode sends 8 bit sequences and requires an auxiliary GPIO 121 * pin for the command/data bit. But in other to allocate a GPIO pin 122 * we need to use fdt, so only support 3 wire mode in this frontend, 123 * at least for now. 124 */ 125 sc->sc_3wiremode = true; 126 127 switch (flags & SSDFB_ATTACH_FLAG_PRODUCT_MASK) { 128 case SSDFB_PRODUCT_SSD1322_GENERIC: 129 if (sc->sc_3wiremode) { 130 sc->sc.sc_transfer_rect = 131 ssdfb_spi_xfer_rect_3wire_ssd1322; 132 } else { 133 sc->sc.sc_transfer_rect = 134 ssdfb_spi_xfer_rect_4wire_ssd1322; 135 } 136 break; 137 default: 138 panic("ssdfb_spi_attach: product not implemented"); 139 } 140 if (sc->sc_3wiremode) { 141 sc->sc.sc_cmd = ssdfb_spi_cmd_3wire; 142 } else { 143 sc->sc.sc_cmd = ssdfb_spi_cmd_4wire; 144 } 145 146 ssdfb_attach(&sc->sc, flags); 147 148 device_printf(sc->sc.sc_dev, "%d-wire SPI interface\n", 149 sc->sc_3wiremode == true ? 3 : 4); 150 } 151 152 static int 153 ssdfb_spi_cmd_3wire(void *cookie, uint8_t *cmd, size_t len, bool usepoll) 154 { 155 struct ssdfb_spi_softc *sc = (struct ssdfb_spi_softc *)cookie; 156 uint8_t bitstream[16 * 9 / 8]; 157 struct bs_state s; 158 159 KASSERT(len > 0 && len <= 16); 160 ssdfb_bitstream_init(&s, bitstream); 161 ssdfb_bitstream_append_cmd(&s, *cmd); 162 cmd++; 163 len--; 164 ssdfb_bitstream_append_data(&s, cmd, len); 165 ssdfb_bitstream_final(&s); 166 167 return spi_send(sc->sc_sh, s.cur - s.base, bitstream); 168 } 169 170 static int 171 ssdfb_spi_xfer_rect_3wire_ssd1322(void *cookie, uint8_t fromcol, uint8_t tocol, 172 uint8_t fromrow, uint8_t torow, uint8_t *p, size_t stride, bool usepoll) 173 { 174 struct ssdfb_spi_softc *sc = (struct ssdfb_spi_softc *)cookie; 175 uint8_t bitstream[128 * 9 / 8]; 176 struct bs_state s; 177 uint8_t row; 178 size_t rlen = (tocol + 1 - fromcol) * 2; 179 int error; 180 181 /* 182 * Unlike iic(4), there is no way to force spi(4) to use polling. 183 */ 184 if (usepoll && !cold) 185 return 0; 186 187 ssdfb_bitstream_init(&s, bitstream); 188 ssdfb_bitstream_append_cmd(&s, SSD1322_CMD_SET_ROW_ADDRESS); 189 ssdfb_bitstream_append_data(&s, &fromrow, 1); 190 ssdfb_bitstream_append_data(&s, &torow, 1); 191 ssdfb_bitstream_append_cmd(&s, SSD1322_CMD_SET_COLUMN_ADDRESS); 192 ssdfb_bitstream_append_data(&s, &fromcol, 1); 193 ssdfb_bitstream_append_data(&s, &tocol, 1); 194 ssdfb_bitstream_append_cmd(&s, SSD1322_CMD_WRITE_RAM); 195 ssdfb_bitstream_final(&s); 196 error = spi_send(sc->sc_sh, s.cur - s.base, bitstream); 197 if (error) 198 return error; 199 200 KASSERT(rlen <= 128); 201 for (row = fromrow; row <= torow; row++) { 202 ssdfb_bitstream_init(&s, bitstream); 203 ssdfb_bitstream_append_data(&s, p, rlen); 204 ssdfb_bitstream_final(&s); 205 error = spi_send(sc->sc_sh, s.cur - s.base, bitstream); 206 if (error) 207 return error; 208 p += stride; 209 } 210 211 return 0; 212 } 213 214 static void 215 ssdfb_bitstream_init(struct bs_state *s, uint8_t *dst) 216 { 217 s->base = s->cur = dst; 218 s->mask = 0x80; 219 } 220 221 static void 222 ssdfb_bitstream_append(struct bs_state *s, uint8_t b, uint8_t srcmask) 223 { 224 while(srcmask) { 225 if (b & srcmask) 226 *s->cur |= s->mask; 227 else 228 *s->cur &= ~s->mask; 229 srcmask >>= 1; 230 s->mask >>= 1; 231 if (!s->mask) { 232 s->mask = 0x80; 233 s->cur++; 234 } 235 } 236 } 237 238 static void 239 ssdfb_bitstream_append_cmd(struct bs_state *s, uint8_t cmd) 240 { 241 ssdfb_bitstream_append(s, 0, 1); 242 ssdfb_bitstream_append(s, cmd, 0x80); 243 } 244 245 static void 246 ssdfb_bitstream_append_data(struct bs_state *s, uint8_t *data, size_t len) 247 { 248 while(len--) { 249 ssdfb_bitstream_append(s, 1, 1); 250 ssdfb_bitstream_append(s, *data++, 0x80); 251 } 252 } 253 254 static void 255 ssdfb_bitstream_final(struct bs_state *s) 256 { 257 uint8_t padding_cmd = SSD1322_CMD_WRITE_RAM; 258 /* padding_cmd = SSDFB_NOP_CMD; */ 259 260 while (s->mask != 0x80) { 261 ssdfb_bitstream_append_cmd(s, padding_cmd); 262 } 263 } 264 265 static void 266 ssdfb_spi_4wire_set_dc(struct ssdfb_spi_softc *sc, int value) 267 { 268 /* TODO: this should toggle an auxilliary GPIO pin */ 269 panic("ssdfb_spi_4wire_set_dc"); 270 } 271 272 static int 273 ssdfb_spi_cmd_4wire(void *cookie, uint8_t *cmd, size_t len, bool usepoll) 274 { 275 struct ssdfb_spi_softc *sc = (struct ssdfb_spi_softc *)cookie; 276 int error; 277 278 ssdfb_spi_4wire_set_dc(sc, 0); 279 error = spi_send(sc->sc_sh, 1, cmd); 280 if (error) 281 return error; 282 if (len > 1) { 283 ssdfb_spi_4wire_set_dc(sc, 1); 284 len--; 285 cmd++; 286 error = spi_send(sc->sc_sh, len, cmd); 287 if (error) 288 return error; 289 } 290 291 return 0; 292 } 293 294 static int 295 ssdfb_spi_xfer_rect_4wire_ssd1322(void *cookie, uint8_t fromcol, uint8_t tocol, 296 uint8_t fromrow, uint8_t torow, uint8_t *p, size_t stride, bool usepoll) 297 { 298 struct ssdfb_spi_softc *sc = (struct ssdfb_spi_softc *)cookie; 299 uint8_t row; 300 size_t rlen = (tocol + 1 - fromcol) * 2; 301 int error; 302 uint8_t cmd; 303 uint8_t data[2]; 304 305 /* 306 * Unlike iic(4), there is no way to force spi(4) to use polling. 307 */ 308 if (usepoll && !cold) 309 return 0; 310 311 ssdfb_spi_4wire_set_dc(sc, 0); 312 cmd = SSD1322_CMD_SET_ROW_ADDRESS; 313 error = spi_send(sc->sc_sh, sizeof(cmd), &cmd); 314 if (error) 315 return error; 316 ssdfb_spi_4wire_set_dc(sc, 1); 317 data[0] = fromrow; 318 data[1] = torow; 319 error = spi_send(sc->sc_sh, sizeof(data), data); 320 if (error) 321 return error; 322 323 ssdfb_spi_4wire_set_dc(sc, 0); 324 cmd = SSD1322_CMD_SET_COLUMN_ADDRESS; 325 error = spi_send(sc->sc_sh, sizeof(cmd), &cmd); 326 if (error) 327 return error; 328 ssdfb_spi_4wire_set_dc(sc, 1); 329 data[0] = fromcol; 330 data[1] = tocol; 331 error = spi_send(sc->sc_sh, sizeof(data), data); 332 if (error) 333 return error; 334 335 ssdfb_spi_4wire_set_dc(sc, 0); 336 cmd = SSD1322_CMD_WRITE_RAM; 337 error = spi_send(sc->sc_sh, sizeof(cmd), &cmd); 338 if (error) 339 return error; 340 341 ssdfb_spi_4wire_set_dc(sc, 1); 342 for (row = fromrow; row <= torow; row++) { 343 error = spi_send(sc->sc_sh, rlen, p); 344 if (error) 345 return error; 346 p += stride; 347 } 348 349 return 0; 350 } 351
Indexes created Tue Sep 23 02:09:52 GMT 2025