drivers/mfd/ipaq-micro.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Compaq iPAQ h3xxx Atmel microcontroller companion support
   4  *
   5  * This is an Atmel AT90LS8535 with a special flashed-in firmware that
   6  * implements the special protocol used by this driver.
   7  *
   8  * based on previous kernel 2.4 version by Andrew Christian
   9  * Author : Alessandro Gardich <gremlin@gremlin.it>
  10  * Author : Dmitry Artamonow <mad_soft@inbox.ru>
  11  * Author : Linus Walleij <linus.walleij@linaro.org>
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/pm.h>
  18 #include <linux/delay.h>
  19 #include <linux/device.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/io.h>
  22 #include <linux/mfd/core.h>
  23 #include <linux/mfd/ipaq-micro.h>
  24 #include <linux/string.h>
  25 #include <linux/random.h>
  26 #include <linux/slab.h>
  27 #include <linux/list.h>
  28
  29 #include <mach/hardware.h>
  30
  31 static void ipaq_micro_trigger_tx(struct ipaq_micro *micro)
  32 {
  33         struct ipaq_micro_txdev *tx = &micro->tx;
  34         struct ipaq_micro_msg *msg = micro->msg;
  35         int i, bp;
  36         u8 checksum;
  37         u32 val;
  38
  39         bp = 0;
  40         tx->buf[bp++] = CHAR_SOF;
  41
  42         checksum = ((msg->id & 0x0f) << 4) | (msg->tx_len & 0x0f);
  43         tx->buf[bp++] = checksum;
  44
  45         for (i = 0; i < msg->tx_len; i++) {
  46                 tx->buf[bp++] = msg->tx_data[i];
  47                 checksum += msg->tx_data[i];
  48         }
  49
  50         tx->buf[bp++] = checksum;
  51         tx->len = bp;
  52         tx->index = 0;
  53
  54         /* Enable interrupt */
  55         val = readl(micro->base + UTCR3);
  56         val |= UTCR3_TIE;
  57         writel(val, micro->base + UTCR3);
  58 }
  59
  60 int ipaq_micro_tx_msg(struct ipaq_micro *micro, struct ipaq_micro_msg *msg)
  61 {
  62         unsigned long flags;
  63
  64         dev_dbg(micro->dev, "TX msg: %02x, %d bytes\n", msg->id, msg->tx_len);
  65
  66         spin_lock_irqsave(&micro->lock, flags);
  67         if (micro->msg) {
  68                 list_add_tail(&msg->node, &micro->queue);
  69                 spin_unlock_irqrestore(&micro->lock, flags);
  70                 return 0;
  71         }
  72         micro->msg = msg;
  73         ipaq_micro_trigger_tx(micro);
  74         spin_unlock_irqrestore(&micro->lock, flags);
  75         return 0;
  76 }
  77 EXPORT_SYMBOL(ipaq_micro_tx_msg);
  78
  79 static void micro_rx_msg(struct ipaq_micro *micro, u8 id, int len, u8 *data)
  80 {
  81         dev_dbg(micro->dev, "RX msg: %02x, %d bytes\n", id, len);
  82
  83         spin_lock(&micro->lock);
  84         switch (id) {
  85         case MSG_VERSION:
  86         case MSG_EEPROM_READ:
  87         case MSG_EEPROM_WRITE:
  88         case MSG_BACKLIGHT:
  89         case MSG_NOTIFY_LED:
  90         case MSG_THERMAL_SENSOR:
  91         case MSG_BATTERY:
  92                 /* Handle synchronous messages */
  93                 if (micro->msg && micro->msg->id == id) {
  94                         struct ipaq_micro_msg *msg = micro->msg;
  95
  96                         memcpy(msg->rx_data, data, len);
  97                         msg->rx_len = len;
  98                         complete(&micro->msg->ack);
  99                         if (!list_empty(&micro->queue)) {
 100                                 micro->msg = list_entry(micro->queue.next,
 101                                                         struct ipaq_micro_msg,
 102                                                         node);
 103                                 list_del_init(&micro->msg->node);
 104                                 ipaq_micro_trigger_tx(micro);
 105                         } else
 106                                 micro->msg = NULL;
 107                         dev_dbg(micro->dev, "OK RX message 0x%02x\n", id);
 108                 } else {
 109                         dev_err(micro->dev,
 110                                 "out of band RX message 0x%02x\n", id);
 111                         if (!micro->msg)
 112                                 dev_info(micro->dev, "no message queued\n");
 113                         else
 114                                 dev_info(micro->dev, "expected message %02x\n",
 115                                          micro->msg->id);
 116                 }
 117                 break;
 118         case MSG_KEYBOARD:
 119                 if (micro->key)
 120                         micro->key(micro->key_data, len, data);
 121                 else
 122                         dev_dbg(micro->dev, "key message ignored, no handle\n");
 123                 break;
 124         case MSG_TOUCHSCREEN:
 125                 if (micro->ts)
 126                         micro->ts(micro->ts_data, len, data);
 127                 else
 128                         dev_dbg(micro->dev, "touchscreen message ignored, no handle\n");
 129                 break;
 130         default:
 131                 dev_err(micro->dev,
 132                         "unknown msg %d [%d] %*ph\n", id, len, len, data);
 133         }
 134         spin_unlock(&micro->lock);
 135 }
 136
 137 static void micro_process_char(struct ipaq_micro *micro, u8 ch)
 138 {
 139         struct ipaq_micro_rxdev *rx = &micro->rx;
 140
 141         switch (rx->state) {
 142         case STATE_SOF: /* Looking for SOF */
 143                 if (ch == CHAR_SOF)
 144                         rx->state = STATE_ID; /* Next byte is the id and len */
 145                 break;
 146         case STATE_ID: /* Looking for id and len byte */
 147                 rx->id = (ch & 0xf0) >> 4;
 148                 rx->len = (ch & 0x0f);
 149                 rx->index = 0;
 150                 rx->chksum = ch;
 151                 rx->state = (rx->len > 0) ? STATE_DATA : STATE_CHKSUM;
 152                 break;
 153         case STATE_DATA: /* Looking for 'len' data bytes */
 154                 rx->chksum += ch;
 155                 rx->buf[rx->index] = ch;
 156                 if (++rx->index == rx->len)
 157                         rx->state = STATE_CHKSUM;
 158                 break;
 159         case STATE_CHKSUM: /* Looking for the checksum */
 160                 if (ch == rx->chksum)
 161                         micro_rx_msg(micro, rx->id, rx->len, rx->buf);
 162                 rx->state = STATE_SOF;
 163                 break;
 164         }
 165 }
 166
 167 static void micro_rx_chars(struct ipaq_micro *micro)
 168 {
 169         u32 status, ch;
 170
 171         while ((status = readl(micro->base + UTSR1)) & UTSR1_RNE) {
 172                 ch = readl(micro->base + UTDR);
 173                 if (status & UTSR1_PRE)
 174                         dev_err(micro->dev, "rx: parity error\n");
 175                 else if (status & UTSR1_FRE)
 176                         dev_err(micro->dev, "rx: framing error\n");
 177                 else if (status & UTSR1_ROR)
 178                         dev_err(micro->dev, "rx: overrun error\n");
 179                 micro_process_char(micro, ch);
 180         }
 181 }
 182
 183 static void ipaq_micro_get_version(struct ipaq_micro *micro)
 184 {
 185         struct ipaq_micro_msg msg = {
 186                 .id = MSG_VERSION,
 187         };
 188
 189         ipaq_micro_tx_msg_sync(micro, &msg);
 190         if (msg.rx_len == 4) {
 191                 memcpy(micro->version, msg.rx_data, 4);
 192                 micro->version[4] = '\0';
 193         } else if (msg.rx_len == 9) {
 194                 memcpy(micro->version, msg.rx_data, 4);
 195                 micro->version[4] = '\0';
 196                 /* Bytes 4-7 are "pack", byte 8 is "boot type" */
 197         } else {
 198                 dev_err(micro->dev,
 199                         "illegal version message %d bytes\n", msg.rx_len);
 200         }
 201 }
 202
 203 static void ipaq_micro_eeprom_read(struct ipaq_micro *micro,
 204                                    u8 address, u8 len, u8 *data)
 205 {
 206         struct ipaq_micro_msg msg = {
 207                 .id = MSG_EEPROM_READ,
 208         };
 209         u8 i;
 210
 211         for (i = 0; i < len; i++) {
 212                 msg.tx_data[0] = address + i;
 213                 msg.tx_data[1] = 1;
 214                 msg.tx_len = 2;
 215                 ipaq_micro_tx_msg_sync(micro, &msg);
 216                 memcpy(data + (i * 2), msg.rx_data, 2);
 217         }
 218 }
 219
 220 static char *ipaq_micro_str(u8 *wchar, u8 len)
 221 {
 222         char retstr[256];
 223         u8 i;
 224
 225         for (i = 0; i < len / 2; i++)
 226                 retstr[i] = wchar[i * 2];
 227         return kstrdup(retstr, GFP_KERNEL);
 228 }
 229
 230 static u16 ipaq_micro_to_u16(u8 *data)
 231 {
 232         return data[1] << 8 | data[0];
 233 }
 234
 235 static void __init ipaq_micro_eeprom_dump(struct ipaq_micro *micro)
 236 {
 237         u8 dump[256];
 238         char *str;
 239
 240         ipaq_micro_eeprom_read(micro, 0, 128, dump);
 241         str = ipaq_micro_str(dump, 10);
 242         if (str) {
 243                 dev_info(micro->dev, "HW version %s\n", str);
 244                 kfree(str);
 245         }
 246         str = ipaq_micro_str(dump+10, 40);
 247         if (str) {
 248                 dev_info(micro->dev, "serial number: %s\n", str);
 249                 /* Feed the random pool with this */
 250                 add_device_randomness(str, strlen(str));
 251                 kfree(str);
 252         }
 253         str = ipaq_micro_str(dump+50, 20);
 254         if (str) {
 255                 dev_info(micro->dev, "module ID: %s\n", str);
 256                 kfree(str);
 257         }
 258         str = ipaq_micro_str(dump+70, 10);
 259         if (str) {
 260                 dev_info(micro->dev, "product revision: %s\n", str);
 261                 kfree(str);
 262         }
 263         dev_info(micro->dev, "product ID: %u\n", ipaq_micro_to_u16(dump+80));
 264         dev_info(micro->dev, "frame rate: %u fps\n",
 265                  ipaq_micro_to_u16(dump+82));
 266         dev_info(micro->dev, "page mode: %u\n", ipaq_micro_to_u16(dump+84));
 267         dev_info(micro->dev, "country ID: %u\n", ipaq_micro_to_u16(dump+86));
 268         dev_info(micro->dev, "color display: %s\n",
 269                  ipaq_micro_to_u16(dump+88) ? "yes" : "no");
 270         dev_info(micro->dev, "ROM size: %u MiB\n", ipaq_micro_to_u16(dump+90));
 271         dev_info(micro->dev, "RAM size: %u KiB\n", ipaq_micro_to_u16(dump+92));
 272         dev_info(micro->dev, "screen: %u x %u\n",
 273                  ipaq_micro_to_u16(dump+94), ipaq_micro_to_u16(dump+96));
 274 }
 275
 276 static void micro_tx_chars(struct ipaq_micro *micro)
 277 {
 278         struct ipaq_micro_txdev *tx = &micro->tx;
 279         u32 val;
 280
 281         while ((tx->index < tx->len) &&
 282                (readl(micro->base + UTSR1) & UTSR1_TNF)) {
 283                 writel(tx->buf[tx->index], micro->base + UTDR);
 284                 tx->index++;
 285         }
 286
 287         /* Stop interrupts */
 288         val = readl(micro->base + UTCR3);
 289         val &= ~UTCR3_TIE;
 290         writel(val, micro->base + UTCR3);
 291 }
 292
 293 static void micro_reset_comm(struct ipaq_micro *micro)
 294 {
 295         struct ipaq_micro_rxdev *rx = &micro->rx;
 296         u32 val;
 297
 298         if (micro->msg)
 299                 complete(&micro->msg->ack);
 300
 301         /* Initialize Serial channel protocol frame */
 302         rx->state = STATE_SOF;  /* Reset the state machine */
 303
 304         /* Set up interrupts */
 305         writel(0x01, micro->sdlc + 0x0); /* Select UART mode */
 306
 307         /* Clean up CR3 */
 308         writel(0x0, micro->base + UTCR3);
 309
 310         /* Format: 8N1 */
 311         writel(UTCR0_8BitData | UTCR0_1StpBit, micro->base + UTCR0);
 312
 313         /* Baud rate: 115200 */
 314         writel(0x0, micro->base + UTCR1);
 315         writel(0x1, micro->base + UTCR2);
 316
 317         /* Clear SR0 */
 318         writel(0xff, micro->base + UTSR0);
 319
 320         /* Enable RX int, disable TX int */
 321         writel(UTCR3_TXE | UTCR3_RXE | UTCR3_RIE, micro->base + UTCR3);
 322         val = readl(micro->base + UTCR3);
 323         val &= ~UTCR3_TIE;
 324         writel(val, micro->base + UTCR3);
 325 }
 326
 327 static irqreturn_t micro_serial_isr(int irq, void *dev_id)
 328 {
 329         struct ipaq_micro *micro = dev_id;
 330         struct ipaq_micro_txdev *tx = &micro->tx;
 331         u32 status;
 332
 333         status = readl(micro->base + UTSR0);
 334         do {
 335                 if (status & (UTSR0_RID | UTSR0_RFS)) {
 336                         if (status & UTSR0_RID)
 337                                 /* Clear the Receiver IDLE bit */
 338                                 writel(UTSR0_RID, micro->base + UTSR0);
 339                         micro_rx_chars(micro);
 340                 }
 341
 342                 /* Clear break bits */
 343                 if (status & (UTSR0_RBB | UTSR0_REB))
 344                         writel(status & (UTSR0_RBB | UTSR0_REB),
 345                                micro->base + UTSR0);
 346
 347                 if (status & UTSR0_TFS)
 348                         micro_tx_chars(micro);
 349
 350                 status = readl(micro->base + UTSR0);
 351
 352         } while (((tx->index < tx->len) && (status & UTSR0_TFS)) ||
 353                  (status & (UTSR0_RFS | UTSR0_RID)));
 354
 355         return IRQ_HANDLED;
 356 }
 357
 358 static const struct mfd_cell micro_cells[] = {
 359         { .name = "ipaq-micro-backlight", },
 360         { .name = "ipaq-micro-battery", },
 361         { .name = "ipaq-micro-keys", },
 362         { .name = "ipaq-micro-ts", },
 363         { .name = "ipaq-micro-leds", },
 364 };
 365
 366 static int __maybe_unused micro_resume(struct device *dev)
 367 {
 368         struct ipaq_micro *micro = dev_get_drvdata(dev);
 369
 370         micro_reset_comm(micro);
 371         mdelay(10);
 372
 373         return 0;
 374 }
 375
 376 static int __init micro_probe(struct platform_device *pdev)
 377 {
 378         struct ipaq_micro *micro;
 379         int ret;
 380         int irq;
 381
 382         micro = devm_kzalloc(&pdev->dev, sizeof(*micro), GFP_KERNEL);
 383         if (!micro)
 384                 return -ENOMEM;
 385
 386         micro->dev = &pdev->dev;
 387
 388         micro->base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
 389         if (IS_ERR(micro->base))
 390                 return PTR_ERR(micro->base);
 391
 392         micro->sdlc = devm_platform_ioremap_resource(pdev, 1);
 393         if (IS_ERR(micro->sdlc))
 394                 return PTR_ERR(micro->sdlc);
 395
 396         micro_reset_comm(micro);
 397
 398         irq = platform_get_irq(pdev, 0);
 399         if (irq < 0)
 400                 return -EINVAL;
 401         ret = devm_request_irq(&pdev->dev, irq, micro_serial_isr,
 402                                IRQF_SHARED, "ipaq-micro",
 403                                micro);
 404         if (ret) {
 405                 dev_err(&pdev->dev, "unable to grab serial port IRQ\n");
 406                 return ret;
 407         } else
 408                 dev_info(&pdev->dev, "grabbed serial port IRQ\n");
 409
 410         spin_lock_init(&micro->lock);
 411         INIT_LIST_HEAD(&micro->queue);
 412         platform_set_drvdata(pdev, micro);
 413
 414         ret = mfd_add_devices(&pdev->dev, pdev->id, micro_cells,
 415                               ARRAY_SIZE(micro_cells), NULL, 0, NULL);
 416         if (ret) {
 417                 dev_err(&pdev->dev, "error adding MFD cells");
 418                 return ret;
 419         }
 420
 421         /* Check version */
 422         ipaq_micro_get_version(micro);
 423         dev_info(&pdev->dev, "Atmel micro ASIC version %s\n", micro->version);
 424         ipaq_micro_eeprom_dump(micro);
 425
 426         return 0;
 427 }
 428
 429 static const struct dev_pm_ops micro_dev_pm_ops = {
 430         SET_SYSTEM_SLEEP_PM_OPS(NULL, micro_resume)
 431 };
 432
 433 static struct platform_driver micro_device_driver = {
 434         .driver   = {
 435                 .name   = "ipaq-h3xxx-micro",
 436                 .pm     = &micro_dev_pm_ops,
 437                 .suppress_bind_attrs = true,
 438         },
 439 };
 440 builtin_platform_driver_probe(micro_device_driver, micro_probe);