drivers/mfd/dm355evm_msp.c

   1 /*
   2  * dm355evm_msp.c - driver for MSP430 firmware on DM355EVM board
   3  *
   4  * Copyright (C) 2008 David Brownell
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <linux/init.h>
  13 #include <linux/mutex.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/clk.h>
  16 #include <linux/module.h>
  17 #include <linux/err.h>
  18 #include <linux/gpio.h>
  19 #include <linux/leds.h>
  20 #include <linux/i2c.h>
  21 #include <linux/mfd/dm355evm_msp.h>
  22
  23
  24 /*
  25  * The DM355 is a DaVinci chip with video support but no C64+ DSP.  Its
  26  * EVM board has an MSP430 programmed with firmware for various board
  27  * support functions.  This driver exposes some of them directly, and
  28  * supports other drivers (e.g. RTC, input) for more complex access.
  29  *
  30  * Because this firmware is entirely board-specific, this file embeds
  31  * knowledge that would be passed as platform_data in a generic driver.
  32  *
  33  * This driver was tested with firmware revision A4.
  34  */
  35
  36 #if IS_ENABLED(CONFIG_INPUT_DM355EVM)
  37 #define msp_has_keyboard()      true
  38 #else
  39 #define msp_has_keyboard()      false
  40 #endif
  41
  42 #if IS_ENABLED(CONFIG_LEDS_GPIO)
  43 #define msp_has_leds()          true
  44 #else
  45 #define msp_has_leds()          false
  46 #endif
  47
  48 #if IS_ENABLED(CONFIG_RTC_DRV_DM355EVM)
  49 #define msp_has_rtc()           true
  50 #else
  51 #define msp_has_rtc()           false
  52 #endif
  53
  54 #if IS_ENABLED(CONFIG_VIDEO_TVP514X)
  55 #define msp_has_tvp()           true
  56 #else
  57 #define msp_has_tvp()           false
  58 #endif
  59
  60
  61 /*----------------------------------------------------------------------*/
  62
  63 /* REVISIT for paranoia's sake, retry reads/writes on error */
  64
  65 static struct i2c_client *msp430;
  66
  67 /**
  68  * dm355evm_msp_write - Writes a register in dm355evm_msp
  69  * @value: the value to be written
  70  * @reg: register address
  71  *
  72  * Returns result of operation - 0 is success, else negative errno
  73  */
  74 int dm355evm_msp_write(u8 value, u8 reg)
  75 {
  76         return i2c_smbus_write_byte_data(msp430, reg, value);
  77 }
  78 EXPORT_SYMBOL(dm355evm_msp_write);
  79
  80 /**
  81  * dm355evm_msp_read - Reads a register from dm355evm_msp
  82  * @reg: register address
  83  *
  84  * Returns result of operation - value, or negative errno
  85  */
  86 int dm355evm_msp_read(u8 reg)
  87 {
  88         return i2c_smbus_read_byte_data(msp430, reg);
  89 }
  90 EXPORT_SYMBOL(dm355evm_msp_read);
  91
  92 /*----------------------------------------------------------------------*/
  93
  94 /*
  95  * Many of the msp430 pins are just used as fixed-direction GPIOs.
  96  * We could export a few more of them this way, if we wanted.
  97  */
  98 #define MSP_GPIO(bit, reg)      ((DM355EVM_MSP_ ## reg) << 3 | (bit))
  99
 100 static const u8 msp_gpios[] = {
 101         /* eight leds */
 102         MSP_GPIO(0, LED), MSP_GPIO(1, LED),
 103         MSP_GPIO(2, LED), MSP_GPIO(3, LED),
 104         MSP_GPIO(4, LED), MSP_GPIO(5, LED),
 105         MSP_GPIO(6, LED), MSP_GPIO(7, LED),
 106         /* SW6 and the NTSC/nPAL jumper */
 107         MSP_GPIO(0, SWITCH1), MSP_GPIO(1, SWITCH1),
 108         MSP_GPIO(2, SWITCH1), MSP_GPIO(3, SWITCH1),
 109         MSP_GPIO(4, SWITCH1),
 110         /* switches on MMC/SD sockets */
 111         /*
 112          * Note: EVMDM355_ECP_VA4.pdf suggests that Bit 2 and 4 should be
 113          * checked for card detection. However on the EVM bit 1 and 3 gives
 114          * this status, for 0 and 1 instance respectively. The pdf also
 115          * suggests that Bit 1 and 3 should be checked for write protection.
 116          * However on the EVM bit 2 and 4 gives this status,for 0 and 1
 117          * instance respectively.
 118          */
 119         MSP_GPIO(2, SDMMC), MSP_GPIO(1, SDMMC), /* mmc0 WP, nCD */
 120         MSP_GPIO(4, SDMMC), MSP_GPIO(3, SDMMC), /* mmc1 WP, nCD */
 121 };
 122
 123 #define MSP_GPIO_REG(offset)    (msp_gpios[(offset)] >> 3)
 124 #define MSP_GPIO_MASK(offset)   BIT(msp_gpios[(offset)] & 0x07)
 125
 126 static int msp_gpio_in(struct gpio_chip *chip, unsigned offset)
 127 {
 128         switch (MSP_GPIO_REG(offset)) {
 129         case DM355EVM_MSP_SWITCH1:
 130         case DM355EVM_MSP_SWITCH2:
 131         case DM355EVM_MSP_SDMMC:
 132                 return 0;
 133         default:
 134                 return -EINVAL;
 135         }
 136 }
 137
 138 static u8 msp_led_cache;
 139
 140 static int msp_gpio_get(struct gpio_chip *chip, unsigned offset)
 141 {
 142         int reg, status;
 143
 144         reg = MSP_GPIO_REG(offset);
 145         status = dm355evm_msp_read(reg);
 146         if (status < 0)
 147                 return status;
 148         if (reg == DM355EVM_MSP_LED)
 149                 msp_led_cache = status;
 150         return !!(status & MSP_GPIO_MASK(offset));
 151 }
 152
 153 static int msp_gpio_out(struct gpio_chip *chip, unsigned offset, int value)
 154 {
 155         int mask, bits;
 156
 157         /* NOTE:  there are some other signals that could be
 158          * packaged as output GPIOs, but they aren't as useful
 159          * as the LEDs ... so for now we don't.
 160          */
 161         if (MSP_GPIO_REG(offset) != DM355EVM_MSP_LED)
 162                 return -EINVAL;
 163
 164         mask = MSP_GPIO_MASK(offset);
 165         bits = msp_led_cache;
 166
 167         bits &= ~mask;
 168         if (value)
 169                 bits |= mask;
 170         msp_led_cache = bits;
 171
 172         return dm355evm_msp_write(bits, DM355EVM_MSP_LED);
 173 }
 174
 175 static void msp_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 176 {
 177         msp_gpio_out(chip, offset, value);
 178 }
 179
 180 static struct gpio_chip dm355evm_msp_gpio = {
 181         .label                  = "dm355evm_msp",
 182         .owner                  = THIS_MODULE,
 183         .direction_input        = msp_gpio_in,
 184         .get                    = msp_gpio_get,
 185         .direction_output       = msp_gpio_out,
 186         .set                    = msp_gpio_set,
 187         .base                   = -EINVAL,              /* dynamic assignment */
 188         .ngpio                  = ARRAY_SIZE(msp_gpios),
 189         .can_sleep              = true,
 190 };
 191
 192 /*----------------------------------------------------------------------*/
 193
 194 static struct device *add_child(struct i2c_client *client, const char *name,
 195                 void *pdata, unsigned pdata_len,
 196                 bool can_wakeup, int irq)
 197 {
 198         struct platform_device  *pdev;
 199         int                     status;
 200
 201         pdev = platform_device_alloc(name, -1);
 202         if (!pdev)
 203                 return ERR_PTR(-ENOMEM);
 204
 205         device_init_wakeup(&pdev->dev, can_wakeup);
 206         pdev->dev.parent = &client->dev;
 207
 208         if (pdata) {
 209                 status = platform_device_add_data(pdev, pdata, pdata_len);
 210                 if (status < 0) {
 211                         dev_dbg(&pdev->dev, "can't add platform_data\n");
 212                         goto put_device;
 213                 }
 214         }
 215
 216         if (irq) {
 217                 struct resource r = {
 218                         .start = irq,
 219                         .flags = IORESOURCE_IRQ,
 220                 };
 221
 222                 status = platform_device_add_resources(pdev, &r, 1);
 223                 if (status < 0) {
 224                         dev_dbg(&pdev->dev, "can't add irq\n");
 225                         goto put_device;
 226                 }
 227         }
 228
 229         status = platform_device_add(pdev);
 230         if (status)
 231                 goto put_device;
 232
 233         return &pdev->dev;
 234
 235 put_device:
 236         platform_device_put(pdev);
 237         dev_err(&client->dev, "failed to add device %s\n", name);
 238         return ERR_PTR(status);
 239 }
 240
 241 static int add_children(struct i2c_client *client)
 242 {
 243         static const struct {
 244                 int offset;
 245                 char *label;
 246         } config_inputs[] = {
 247                 /* 8 == right after the LEDs */
 248                 { 8 + 0, "sw6_1", },
 249                 { 8 + 1, "sw6_2", },
 250                 { 8 + 2, "sw6_3", },
 251                 { 8 + 3, "sw6_4", },
 252                 { 8 + 4, "NTSC/nPAL", },
 253         };
 254
 255         struct device   *child;
 256         int             status;
 257         int             i;
 258
 259         /* GPIO-ish stuff */
 260         dm355evm_msp_gpio.parent = &client->dev;
 261         status = gpiochip_add_data(&dm355evm_msp_gpio, NULL);
 262         if (status < 0)
 263                 return status;
 264
 265         /* LED output */
 266         if (msp_has_leds()) {
 267 #define GPIO_LED(l)     .name = l, .active_low = true
 268                 static struct gpio_led evm_leds[] = {
 269                         { GPIO_LED("dm355evm::ds14"),
 270                                 .default_trigger = "heartbeat", },
 271                         { GPIO_LED("dm355evm::ds15"),
 272                                 .default_trigger = "mmc0", },
 273                         { GPIO_LED("dm355evm::ds16"),
 274                                 /* could also be a CE-ATA drive */
 275                                 .default_trigger = "mmc1", },
 276                         { GPIO_LED("dm355evm::ds17"),
 277                                 .default_trigger = "nand-disk", },
 278                         { GPIO_LED("dm355evm::ds18"), },
 279                         { GPIO_LED("dm355evm::ds19"), },
 280                         { GPIO_LED("dm355evm::ds20"), },
 281                         { GPIO_LED("dm355evm::ds21"), },
 282                 };
 283 #undef GPIO_LED
 284
 285                 struct gpio_led_platform_data evm_led_data = {
 286                         .num_leds       = ARRAY_SIZE(evm_leds),
 287                         .leds           = evm_leds,
 288                 };
 289
 290                 for (i = 0; i < ARRAY_SIZE(evm_leds); i++)
 291                         evm_leds[i].gpio = i + dm355evm_msp_gpio.base;
 292
 293                 /* NOTE:  these are the only fully programmable LEDs
 294                  * on the board, since GPIO-61/ds22 (and many signals
 295                  * going to DC7) must be used for AEMIF address lines
 296                  * unless the top 1 GB of NAND is unused...
 297                  */
 298                 child = add_child(client, "leds-gpio",
 299                                 &evm_led_data, sizeof(evm_led_data),
 300                                 false, 0);
 301                 if (IS_ERR(child))
 302                         return PTR_ERR(child);
 303         }
 304
 305         /* configuration inputs */
 306         for (i = 0; i < ARRAY_SIZE(config_inputs); i++) {
 307                 int gpio = dm355evm_msp_gpio.base + config_inputs[i].offset;
 308
 309                 gpio_request_one(gpio, GPIOF_IN, config_inputs[i].label);
 310
 311                 /* make it easy for userspace to see these */
 312                 gpio_export(gpio, false);
 313         }
 314
 315         /* MMC/SD inputs -- right after the last config input */
 316         if (dev_get_platdata(&client->dev)) {
 317                 void (*mmcsd_setup)(unsigned) = dev_get_platdata(&client->dev);
 318
 319                 mmcsd_setup(dm355evm_msp_gpio.base + 8 + 5);
 320         }
 321
 322         /* RTC is a 32 bit counter, no alarm */
 323         if (msp_has_rtc()) {
 324                 child = add_child(client, "rtc-dm355evm",
 325                                 NULL, 0, false, 0);
 326                 if (IS_ERR(child))
 327                         return PTR_ERR(child);
 328         }
 329
 330         /* input from buttons and IR remote (uses the IRQ) */
 331         if (msp_has_keyboard()) {
 332                 child = add_child(client, "dm355evm_keys",
 333                                 NULL, 0, true, client->irq);
 334                 if (IS_ERR(child))
 335                         return PTR_ERR(child);
 336         }
 337
 338         return 0;
 339 }
 340
 341 /*----------------------------------------------------------------------*/
 342
 343 static void dm355evm_command(unsigned command)
 344 {
 345         int status;
 346
 347         status = dm355evm_msp_write(command, DM355EVM_MSP_COMMAND);
 348         if (status < 0)
 349                 dev_err(&msp430->dev, "command %d failure %d\n",
 350                                 command, status);
 351 }
 352
 353 static void dm355evm_power_off(void)
 354 {
 355         dm355evm_command(MSP_COMMAND_POWEROFF);
 356 }
 357
 358 static int dm355evm_msp_remove(struct i2c_client *client)
 359 {
 360         pm_power_off = NULL;
 361         msp430 = NULL;
 362         return 0;
 363 }
 364
 365 static int
 366 dm355evm_msp_probe(struct i2c_client *client, const struct i2c_device_id *id)
 367 {
 368         int             status;
 369         const char      *video = msp_has_tvp() ? "TVP5146" : "imager";
 370
 371         if (msp430)
 372                 return -EBUSY;
 373         msp430 = client;
 374
 375         /* display revision status; doubles as sanity check */
 376         status = dm355evm_msp_read(DM355EVM_MSP_FIRMREV);
 377         if (status < 0)
 378                 goto fail;
 379         dev_info(&client->dev, "firmware v.%02X, %s as video-in\n",
 380                         status, video);
 381
 382         /* mux video input:  either tvp5146 or some external imager */
 383         status = dm355evm_msp_write(msp_has_tvp() ? 0 : MSP_VIDEO_IMAGER,
 384                         DM355EVM_MSP_VIDEO_IN);
 385         if (status < 0)
 386                 dev_warn(&client->dev, "error %d muxing %s as video-in\n",
 387                         status, video);
 388
 389         /* init LED cache, and turn off the LEDs */
 390         msp_led_cache = 0xff;
 391         dm355evm_msp_write(msp_led_cache, DM355EVM_MSP_LED);
 392
 393         /* export capabilities we support */
 394         status = add_children(client);
 395         if (status < 0)
 396                 goto fail;
 397
 398         /* PM hookup */
 399         pm_power_off = dm355evm_power_off;
 400
 401         return 0;
 402
 403 fail:
 404         /* FIXME remove children ... */
 405         dm355evm_msp_remove(client);
 406         return status;
 407 }
 408
 409 static const struct i2c_device_id dm355evm_msp_ids[] = {
 410         { "dm355evm_msp", 0 },
 411         { /* end of list */ },
 412 };
 413 MODULE_DEVICE_TABLE(i2c, dm355evm_msp_ids);
 414
 415 static struct i2c_driver dm355evm_msp_driver = {
 416         .driver.name    = "dm355evm_msp",
 417         .id_table       = dm355evm_msp_ids,
 418         .probe          = dm355evm_msp_probe,
 419         .remove         = dm355evm_msp_remove,
 420 };
 421
 422 static int __init dm355evm_msp_init(void)
 423 {
 424         return i2c_add_driver(&dm355evm_msp_driver);
 425 }
 426 subsys_initcall(dm355evm_msp_init);
 427
 428 static void __exit dm355evm_msp_exit(void)
 429 {
 430         i2c_del_driver(&dm355evm_msp_driver);
 431 }
 432 module_exit(dm355evm_msp_exit);
 433
 434 MODULE_DESCRIPTION("Interface to MSP430 firmware on DM355EVM");
 435 MODULE_LICENSE("GPL");