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/err.h>
  17 #include <linux/gpio.h>
  18 #include <linux/leds.h>
  19 #include <linux/i2c.h>
  20 #include <linux/i2c/dm355evm_msp.h>
  21
  22
  23 /*
  24  * The DM355 is a DaVinci chip with video support but no C64+ DSP.  Its
  25  * EVM board has an MSP430 programmed with firmware for various board
  26  * support functions.  This driver exposes some of them directly, and
  27  * supports other drivers (e.g. RTC, input) for more complex access.
  28  *
  29  * Because this firmware is entirely board-specific, this file embeds
  30  * knowledge that would be passed as platform_data in a generic driver.
  31  *
  32  * This driver was tested with firmware revision A4.
  33  */
  34
  35 #if defined(CONFIG_INPUT_DM355EVM) || defined(CONFIG_INPUT_DM355EVM_MODULE)
  36 #define msp_has_keyboard()      true
  37 #else
  38 #define msp_has_keyboard()      false
  39 #endif
  40
  41 #if defined(CONFIG_LEDS_GPIO) || defined(CONFIG_LEDS_GPIO_MODULE)
  42 #define msp_has_leds()          true
  43 #else
  44 #define msp_has_leds()          false
  45 #endif
  46
  47 #if defined(CONFIG_RTC_DRV_DM355EVM) || defined(CONFIG_RTC_DRV_DM355EVM_MODULE)
  48 #define msp_has_rtc()           true
  49 #else
  50 #define msp_has_rtc()           false
  51 #endif
  52
  53 #if defined(CONFIG_VIDEO_TVP514X) || defined(CONFIG_VIDEO_TVP514X_MODULE)
  54 #define msp_has_tvp()           true
  55 #else
  56 #define msp_has_tvp()           false
  57 #endif
  58
  59
  60 /*----------------------------------------------------------------------*/
  61
  62 /* REVISIT for paranoia's sake, retry reads/writes on error */
  63
  64 static struct i2c_client *msp430;
  65
  66 /**
  67  * dm355evm_msp_write - Writes a register in dm355evm_msp
  68  * @value: the value to be written
  69  * @reg: register address
  70  *
  71  * Returns result of operation - 0 is success, else negative errno
  72  */
  73 int dm355evm_msp_write(u8 value, u8 reg)
  74 {
  75         return i2c_smbus_write_byte_data(msp430, reg, value);
  76 }
  77 EXPORT_SYMBOL(dm355evm_msp_write);
  78
  79 /**
  80  * dm355evm_msp_read - Reads a register from dm355evm_msp
  81  * @reg: register address
  82  *
  83  * Returns result of operation - value, or negative errno
  84  */
  85 int dm355evm_msp_read(u8 reg)
  86 {
  87         return i2c_smbus_read_byte_data(msp430, reg);
  88 }
  89 EXPORT_SYMBOL(dm355evm_msp_read);
  90
  91 /*----------------------------------------------------------------------*/
  92
  93 /*
  94  * Many of the msp430 pins are just used as fixed-direction GPIOs.
  95  * We could export a few more of them this way, if we wanted.
  96  */
  97 #define MSP_GPIO(bit,reg)       ((DM355EVM_MSP_ ## reg) << 3 | (bit))
  98
  99 static const u8 msp_gpios[] = {
 100         /* eight leds */
 101         MSP_GPIO(0, LED), MSP_GPIO(1, LED),
 102         MSP_GPIO(2, LED), MSP_GPIO(3, LED),
 103         MSP_GPIO(4, LED), MSP_GPIO(5, LED),
 104         MSP_GPIO(6, LED), MSP_GPIO(7, LED),
 105         /* SW6 and the NTSC/nPAL jumper */
 106         MSP_GPIO(0, SWITCH1), MSP_GPIO(1, SWITCH1),
 107         MSP_GPIO(2, SWITCH1), MSP_GPIO(3, SWITCH1),
 108         MSP_GPIO(4, SWITCH1),
 109         /* switches on MMC/SD sockets */
 110         MSP_GPIO(1, SDMMC), MSP_GPIO(2, SDMMC), /* mmc0 WP, nCD */
 111         MSP_GPIO(3, SDMMC), MSP_GPIO(4, SDMMC), /* mmc1 WP, nCD */
 112 };
 113
 114 #define MSP_GPIO_REG(offset)    (msp_gpios[(offset)] >> 3)
 115 #define MSP_GPIO_MASK(offset)   BIT(msp_gpios[(offset)] & 0x07)
 116
 117 static int msp_gpio_in(struct gpio_chip *chip, unsigned offset)
 118 {
 119         switch (MSP_GPIO_REG(offset)) {
 120         case DM355EVM_MSP_SWITCH1:
 121         case DM355EVM_MSP_SWITCH2:
 122         case DM355EVM_MSP_SDMMC:
 123                 return 0;
 124         default:
 125                 return -EINVAL;
 126         }
 127 }
 128
 129 static u8 msp_led_cache;
 130
 131 static int msp_gpio_get(struct gpio_chip *chip, unsigned offset)
 132 {
 133         int reg, status;
 134
 135         reg = MSP_GPIO_REG(offset);
 136         status = dm355evm_msp_read(reg);
 137         if (status < 0)
 138                 return status;
 139         if (reg == DM355EVM_MSP_LED)
 140                 msp_led_cache = status;
 141         return status & MSP_GPIO_MASK(offset);
 142 }
 143
 144 static int msp_gpio_out(struct gpio_chip *chip, unsigned offset, int value)
 145 {
 146         int mask, bits;
 147
 148         /* NOTE:  there are some other signals that could be
 149          * packaged as output GPIOs, but they aren't as useful
 150          * as the LEDs ... so for now we don't.
 151          */
 152         if (MSP_GPIO_REG(offset) != DM355EVM_MSP_LED)
 153                 return -EINVAL;
 154
 155         mask = MSP_GPIO_MASK(offset);
 156         bits = msp_led_cache;
 157
 158         bits &= ~mask;
 159         if (value)
 160                 bits |= mask;
 161         msp_led_cache = bits;
 162
 163         return dm355evm_msp_write(bits, DM355EVM_MSP_LED);
 164 }
 165
 166 static void msp_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 167 {
 168         msp_gpio_out(chip, offset, value);
 169 }
 170
 171 static struct gpio_chip dm355evm_msp_gpio = {
 172         .label                  = "dm355evm_msp",
 173         .owner                  = THIS_MODULE,
 174         .direction_input        = msp_gpio_in,
 175         .get                    = msp_gpio_get,
 176         .direction_output       = msp_gpio_out,
 177         .set                    = msp_gpio_set,
 178         .base                   = -EINVAL,              /* dynamic assignment */
 179         .ngpio                  = ARRAY_SIZE(msp_gpios),
 180         .can_sleep              = true,
 181 };
 182
 183 /*----------------------------------------------------------------------*/
 184
 185 static struct device *add_child(struct i2c_client *client, const char *name,
 186                 void *pdata, unsigned pdata_len,
 187                 bool can_wakeup, int irq)
 188 {
 189         struct platform_device  *pdev;
 190         int                     status;
 191
 192         pdev = platform_device_alloc(name, -1);
 193         if (!pdev) {
 194                 dev_dbg(&client->dev, "can't alloc dev\n");
 195                 status = -ENOMEM;
 196                 goto err;
 197         }
 198
 199         device_init_wakeup(&pdev->dev, can_wakeup);
 200         pdev->dev.parent = &client->dev;
 201
 202         if (pdata) {
 203                 status = platform_device_add_data(pdev, pdata, pdata_len);
 204                 if (status < 0) {
 205                         dev_dbg(&pdev->dev, "can't add platform_data\n");
 206                         goto err;
 207                 }
 208         }
 209
 210         if (irq) {
 211                 struct resource r = {
 212                         .start = irq,
 213                         .flags = IORESOURCE_IRQ,
 214                 };
 215
 216                 status = platform_device_add_resources(pdev, &r, 1);
 217                 if (status < 0) {
 218                         dev_dbg(&pdev->dev, "can't add irq\n");
 219                         goto err;
 220                 }
 221         }
 222
 223         status = platform_device_add(pdev);
 224
 225 err:
 226         if (status < 0) {
 227                 platform_device_put(pdev);
 228                 dev_err(&client->dev, "can't add %s dev\n", name);
 229                 return ERR_PTR(status);
 230         }
 231         return &pdev->dev;
 232 }
 233
 234 static int add_children(struct i2c_client *client)
 235 {
 236         static const struct {
 237                 int offset;
 238                 char *label;
 239         } config_inputs[] = {
 240                 /* 8 == right after the LEDs */
 241                 { 8 + 0, "sw6_1", },
 242                 { 8 + 1, "sw6_2", },
 243                 { 8 + 2, "sw6_3", },
 244                 { 8 + 3, "sw6_4", },
 245                 { 8 + 4, "NTSC/nPAL", },
 246         };
 247
 248         struct device   *child;
 249         int             status;
 250         int             i;
 251
 252         /* GPIO-ish stuff */
 253         dm355evm_msp_gpio.dev = &client->dev;
 254         status = gpiochip_add(&dm355evm_msp_gpio);
 255         if (status < 0)
 256                 return status;
 257
 258         /* LED output */
 259         if (msp_has_leds()) {
 260 #define GPIO_LED(l)     .name = l, .active_low = true
 261                 static struct gpio_led evm_leds[] = {
 262                         { GPIO_LED("dm355evm::ds14"),
 263                                 .default_trigger = "heartbeat", },
 264                         { GPIO_LED("dm355evm::ds15"),
 265                                 .default_trigger = "mmc0", },
 266                         { GPIO_LED("dm355evm::ds16"),
 267                                 /* could also be a CE-ATA drive */
 268                                 .default_trigger = "mmc1", },
 269                         { GPIO_LED("dm355evm::ds17"),
 270                                 .default_trigger = "nand-disk", },
 271                         { GPIO_LED("dm355evm::ds18"), },
 272                         { GPIO_LED("dm355evm::ds19"), },
 273                         { GPIO_LED("dm355evm::ds20"), },
 274                         { GPIO_LED("dm355evm::ds21"), },
 275                 };
 276 #undef GPIO_LED
 277
 278                 struct gpio_led_platform_data evm_led_data = {
 279                         .num_leds       = ARRAY_SIZE(evm_leds),
 280                         .leds           = evm_leds,
 281                 };
 282
 283                 for (i = 0; i < ARRAY_SIZE(evm_leds); i++)
 284                         evm_leds[i].gpio = i + dm355evm_msp_gpio.base;
 285
 286                 /* NOTE:  these are the only fully programmable LEDs
 287                  * on the board, since GPIO-61/ds22 (and many signals
 288                  * going to DC7) must be used for AEMIF address lines
 289                  * unless the top 1 GB of NAND is unused...
 290                  */
 291                 child = add_child(client, "leds-gpio",
 292                                 &evm_led_data, sizeof(evm_led_data),
 293                                 false, 0);
 294                 if (IS_ERR(child))
 295                         return PTR_ERR(child);
 296         }
 297
 298         /* configuration inputs */
 299         for (i = 0; i < ARRAY_SIZE(config_inputs); i++) {
 300                 int gpio = dm355evm_msp_gpio.base + config_inputs[i].offset;
 301
 302                 gpio_request(gpio, config_inputs[i].label);
 303                 gpio_direction_input(gpio);
 304
 305                 /* make it easy for userspace to see these */
 306                 gpio_export(gpio, false);
 307         }
 308
 309         /* MMC/SD inputs -- right after the last config input */
 310         if (client->dev.platform_data) {
 311                 void (*mmcsd_setup)(unsigned) = client->dev.platform_data;
 312
 313                 mmcsd_setup(dm355evm_msp_gpio.base + 8 + 5);
 314         }
 315
 316         /* RTC is a 32 bit counter, no alarm */
 317         if (msp_has_rtc()) {
 318                 child = add_child(client, "rtc-dm355evm",
 319                                 NULL, 0, false, 0);
 320                 if (IS_ERR(child))
 321                         return PTR_ERR(child);
 322         }
 323
 324         /* input from buttons and IR remote (uses the IRQ) */
 325         if (msp_has_keyboard()) {
 326                 child = add_child(client, "dm355evm_keys",
 327                                 NULL, 0, true, client->irq);
 328                 if (IS_ERR(child))
 329                         return PTR_ERR(child);
 330         }
 331
 332         return 0;
 333 }
 334
 335 /*----------------------------------------------------------------------*/
 336
 337 static void dm355evm_command(unsigned command)
 338 {
 339         int status;
 340
 341         status = dm355evm_msp_write(command, DM355EVM_MSP_COMMAND);
 342         if (status < 0)
 343                 dev_err(&msp430->dev, "command %d failure %d\n",
 344                                 command, status);
 345 }
 346
 347 static void dm355evm_power_off(void)
 348 {
 349         dm355evm_command(MSP_COMMAND_POWEROFF);
 350 }
 351
 352 static int dm355evm_msp_remove(struct i2c_client *client)
 353 {
 354         pm_power_off = NULL;
 355         msp430 = NULL;
 356         return 0;
 357 }
 358
 359 static int
 360 dm355evm_msp_probe(struct i2c_client *client, const struct i2c_device_id *id)
 361 {
 362         int             status;
 363         const char      *video = msp_has_tvp() ? "TVP5146" : "imager";
 364
 365         if (msp430)
 366                 return -EBUSY;
 367         msp430 = client;
 368
 369         /* display revision status; doubles as sanity check */
 370         status = dm355evm_msp_read(DM355EVM_MSP_FIRMREV);
 371         if (status < 0)
 372                 goto fail;
 373         dev_info(&client->dev, "firmware v.%02X, %s as video-in\n",
 374                         status, video);
 375
 376         /* mux video input:  either tvp5146 or some external imager */
 377         status = dm355evm_msp_write(msp_has_tvp() ? 0 : MSP_VIDEO_IMAGER,
 378                         DM355EVM_MSP_VIDEO_IN);
 379         if (status < 0)
 380                 dev_warn(&client->dev, "error %d muxing %s as video-in\n",
 381                         status, video);
 382
 383         /* init LED cache, and turn off the LEDs */
 384         msp_led_cache = 0xff;
 385         dm355evm_msp_write(msp_led_cache, DM355EVM_MSP_LED);
 386
 387         /* export capabilities we support */
 388         status = add_children(client);
 389         if (status < 0)
 390                 goto fail;
 391
 392         /* PM hookup */
 393         pm_power_off = dm355evm_power_off;
 394
 395         return 0;
 396
 397 fail:
 398         /* FIXME remove children ... */
 399         dm355evm_msp_remove(client);
 400         return status;
 401 }
 402
 403 static const struct i2c_device_id dm355evm_msp_ids[] = {
 404         { "dm355evm_msp", 0 },
 405         { /* end of list */ },
 406 };
 407 MODULE_DEVICE_TABLE(i2c, dm355evm_msp_ids);
 408
 409 static struct i2c_driver dm355evm_msp_driver = {
 410         .driver.name    = "dm355evm_msp",
 411         .id_table       = dm355evm_msp_ids,
 412         .probe          = dm355evm_msp_probe,
 413         .remove         = dm355evm_msp_remove,
 414 };
 415
 416 static int __init dm355evm_msp_init(void)
 417 {
 418         return i2c_add_driver(&dm355evm_msp_driver);
 419 }
 420 subsys_initcall(dm355evm_msp_init);
 421
 422 static void __exit dm355evm_msp_exit(void)
 423 {
 424         i2c_del_driver(&dm355evm_msp_driver);
 425 }
 426 module_exit(dm355evm_msp_exit);
 427
 428 MODULE_DESCRIPTION("Interface to MSP430 firmware on DM355EVM");
 429 MODULE_LICENSE("GPL");