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_KEYBOARD_DM355EVM) \
  36                 || defined(CONFIG_KEYBOARD_DM355EVM_MODULE)
  37 #define msp_has_keyboard()      true
  38 #else
  39 #define msp_has_keyboard()      false
  40 #endif
  41
  42 #if defined(CONFIG_LEDS_GPIO) || defined(CONFIG_LEDS_GPIO_MODULE)
  43 #define msp_has_leds()          true
  44 #else
  45 #define msp_has_leds()          false
  46 #endif
  47
  48 #if defined(CONFIG_RTC_DRV_DM355EVM) || defined(CONFIG_RTC_DRV_DM355EVM_MODULE)
  49 #define msp_has_rtc()           true
  50 #else
  51 #define msp_has_rtc()           false
  52 #endif
  53
  54 #if defined(CONFIG_VIDEO_TVP514X) || defined(CONFIG_VIDEO_TVP514X_MODULE)
  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 };
 111
 112 #define MSP_GPIO_REG(offset)    (msp_gpios[(offset)] >> 3)
 113 #define MSP_GPIO_MASK(offset)   BIT(msp_gpios[(offset)] & 0x07)
 114
 115 static int msp_gpio_in(struct gpio_chip *chip, unsigned offset)
 116 {
 117         switch (MSP_GPIO_REG(offset)) {
 118         case DM355EVM_MSP_SWITCH1:
 119         case DM355EVM_MSP_SWITCH2:
 120         case DM355EVM_MSP_SDMMC:
 121                 return 0;
 122         default:
 123                 return -EINVAL;
 124         }
 125 }
 126
 127 static u8 msp_led_cache;
 128
 129 static int msp_gpio_get(struct gpio_chip *chip, unsigned offset)
 130 {
 131         int reg, status;
 132
 133         reg = MSP_GPIO_REG(offset);
 134         status = dm355evm_msp_read(reg);
 135         if (status < 0)
 136                 return status;
 137         if (reg == DM355EVM_MSP_LED)
 138                 msp_led_cache = status;
 139         return status & MSP_GPIO_MASK(offset);
 140 }
 141
 142 static int msp_gpio_out(struct gpio_chip *chip, unsigned offset, int value)
 143 {
 144         int mask, bits;
 145
 146         /* NOTE:  there are some other signals that could be
 147          * packaged as output GPIOs, but they aren't as useful
 148          * as the LEDs ... so for now we don't.
 149          */
 150         if (MSP_GPIO_REG(offset) != DM355EVM_MSP_LED)
 151                 return -EINVAL;
 152
 153         mask = MSP_GPIO_MASK(offset);
 154         bits = msp_led_cache;
 155
 156         bits &= ~mask;
 157         if (value)
 158                 bits |= mask;
 159         msp_led_cache = bits;
 160
 161         return dm355evm_msp_write(bits, DM355EVM_MSP_LED);
 162 }
 163
 164 static void msp_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 165 {
 166         msp_gpio_out(chip, offset, value);
 167 }
 168
 169 static struct gpio_chip dm355evm_msp_gpio = {
 170         .label                  = "dm355evm_msp",
 171         .owner                  = THIS_MODULE,
 172         .direction_input        = msp_gpio_in,
 173         .get                    = msp_gpio_get,
 174         .direction_output       = msp_gpio_out,
 175         .set                    = msp_gpio_set,
 176         .base                   = -EINVAL,              /* dynamic assignment */
 177         .ngpio                  = ARRAY_SIZE(msp_gpios),
 178         .can_sleep              = true,
 179 };
 180
 181 /*----------------------------------------------------------------------*/
 182
 183 static struct device *add_child(struct i2c_client *client, const char *name,
 184                 void *pdata, unsigned pdata_len,
 185                 bool can_wakeup, int irq)
 186 {
 187         struct platform_device  *pdev;
 188         int                     status;
 189
 190         pdev = platform_device_alloc(name, -1);
 191         if (!pdev) {
 192                 dev_dbg(&client->dev, "can't alloc dev\n");
 193                 status = -ENOMEM;
 194                 goto err;
 195         }
 196
 197         device_init_wakeup(&pdev->dev, can_wakeup);
 198         pdev->dev.parent = &client->dev;
 199
 200         if (pdata) {
 201                 status = platform_device_add_data(pdev, pdata, pdata_len);
 202                 if (status < 0) {
 203                         dev_dbg(&pdev->dev, "can't add platform_data\n");
 204                         goto err;
 205                 }
 206         }
 207
 208         if (irq) {
 209                 struct resource r = {
 210                         .start = irq,
 211                         .flags = IORESOURCE_IRQ,
 212                 };
 213
 214                 status = platform_device_add_resources(pdev, &r, 1);
 215                 if (status < 0) {
 216                         dev_dbg(&pdev->dev, "can't add irq\n");
 217                         goto err;
 218                 }
 219         }
 220
 221         status = platform_device_add(pdev);
 222
 223 err:
 224         if (status < 0) {
 225                 platform_device_put(pdev);
 226                 dev_err(&client->dev, "can't add %s dev\n", name);
 227                 return ERR_PTR(status);
 228         }
 229         return &pdev->dev;
 230 }
 231
 232 static int add_children(struct i2c_client *client)
 233 {
 234         static const struct {
 235                 int offset;
 236                 char *label;
 237         } config_inputs[] = {
 238                 /* 8 == right after the LEDs */
 239                 { 8 + 0, "sw6_1", },
 240                 { 8 + 1, "sw6_2", },
 241                 { 8 + 2, "sw6_3", },
 242                 { 8 + 3, "sw6_4", },
 243                 { 8 + 4, "NTSC/nPAL", },
 244         };
 245
 246         struct device   *child;
 247         int             status;
 248         int             i;
 249
 250         /* GPIO-ish stuff */
 251         dm355evm_msp_gpio.dev = &client->dev;
 252         status = gpiochip_add(&dm355evm_msp_gpio);
 253         if (status < 0)
 254                 return status;
 255
 256         /* LED output */
 257         if (msp_has_leds()) {
 258 #define GPIO_LED(l)     .name = l, .active_low = true
 259                 static struct gpio_led evm_leds[] = {
 260                         { GPIO_LED("dm355evm::ds14"),
 261                                 .default_trigger = "heartbeat", },
 262                         { GPIO_LED("dm355evm::ds15"),
 263                                 .default_trigger = "mmc0", },
 264                         { GPIO_LED("dm355evm::ds16"),
 265                                 /* could also be a CE-ATA drive */
 266                                 .default_trigger = "mmc1", },
 267                         { GPIO_LED("dm355evm::ds17"),
 268                                 .default_trigger = "nand-disk", },
 269                         { GPIO_LED("dm355evm::ds18"), },
 270                         { GPIO_LED("dm355evm::ds19"), },
 271                         { GPIO_LED("dm355evm::ds20"), },
 272                         { GPIO_LED("dm355evm::ds21"), },
 273                 };
 274 #undef GPIO_LED
 275
 276                 struct gpio_led_platform_data evm_led_data = {
 277                         .num_leds       = ARRAY_SIZE(evm_leds),
 278                         .leds           = evm_leds,
 279                 };
 280
 281                 for (i = 0; i < ARRAY_SIZE(evm_leds); i++)
 282                         evm_leds[i].gpio = i + dm355evm_msp_gpio.base;
 283
 284                 /* NOTE:  these are the only fully programmable LEDs
 285                  * on the board, since GPIO-61/ds22 (and many signals
 286                  * going to DC7) must be used for AEMIF address lines
 287                  * unless the top 1 GB of NAND is unused...
 288                  */
 289                 child = add_child(client, "leds-gpio",
 290                                 &evm_led_data, sizeof(evm_led_data),
 291                                 false, 0);
 292                 if (IS_ERR(child))
 293                         return PTR_ERR(child);
 294         }
 295
 296         /* configuration inputs */
 297         for (i = 0; i < ARRAY_SIZE(config_inputs); i++) {
 298                 int gpio = dm355evm_msp_gpio.base + config_inputs[i].offset;
 299
 300                 gpio_request(gpio, config_inputs[i].label);
 301                 gpio_direction_input(gpio);
 302
 303                 /* make it easy for userspace to see these */
 304                 gpio_export(gpio, false);
 305         }
 306
 307         /* RTC is a 32 bit counter, no alarm */
 308         if (msp_has_rtc()) {
 309                 child = add_child(client, "rtc-dm355evm",
 310                                 NULL, 0, false, 0);
 311                 if (IS_ERR(child))
 312                         return PTR_ERR(child);
 313         }
 314
 315         /* input from buttons and IR remote (uses the IRQ) */
 316         if (msp_has_keyboard()) {
 317                 child = add_child(client, "dm355evm_keys",
 318                                 NULL, 0, true, client->irq);
 319                 if (IS_ERR(child))
 320                         return PTR_ERR(child);
 321         }
 322
 323         return 0;
 324 }
 325
 326 /*----------------------------------------------------------------------*/
 327
 328 static void dm355evm_command(unsigned command)
 329 {
 330         int status;
 331
 332         status = dm355evm_msp_write(command, DM355EVM_MSP_COMMAND);
 333         if (status < 0)
 334                 dev_err(&msp430->dev, "command %d failure %d\n",
 335                                 command, status);
 336 }
 337
 338 static void dm355evm_power_off(void)
 339 {
 340         dm355evm_command(MSP_COMMAND_POWEROFF);
 341 }
 342
 343 static int dm355evm_msp_remove(struct i2c_client *client)
 344 {
 345         pm_power_off = NULL;
 346         msp430 = NULL;
 347         return 0;
 348 }
 349
 350 static int
 351 dm355evm_msp_probe(struct i2c_client *client, const struct i2c_device_id *id)
 352 {
 353         int             status;
 354         const char      *video = msp_has_tvp() ? "TVP5146" : "imager";
 355
 356         if (msp430)
 357                 return -EBUSY;
 358         msp430 = client;
 359
 360         /* display revision status; doubles as sanity check */
 361         status = dm355evm_msp_read(DM355EVM_MSP_FIRMREV);
 362         if (status < 0)
 363                 goto fail;
 364         dev_info(&client->dev, "firmware v.%02X, %s as video-in\n",
 365                         status, video);
 366
 367         /* mux video input:  either tvp5146 or some external imager */
 368         status = dm355evm_msp_write(msp_has_tvp() ? 0 : MSP_VIDEO_IMAGER,
 369                         DM355EVM_MSP_VIDEO_IN);
 370         if (status < 0)
 371                 dev_warn(&client->dev, "error %d muxing %s as video-in\n",
 372                         status, video);
 373
 374         /* init LED cache, and turn off the LEDs */
 375         msp_led_cache = 0xff;
 376         dm355evm_msp_write(msp_led_cache, DM355EVM_MSP_LED);
 377
 378         /* export capabilities we support */
 379         status = add_children(client);
 380         if (status < 0)
 381                 goto fail;
 382
 383         /* PM hookup */
 384         pm_power_off = dm355evm_power_off;
 385
 386         return 0;
 387
 388 fail:
 389         /* FIXME remove children ... */
 390         dm355evm_msp_remove(client);
 391         return status;
 392 }
 393
 394 static const struct i2c_device_id dm355evm_msp_ids[] = {
 395         { "dm355evm_msp", 0 },
 396         { /* end of list */ },
 397 };
 398 MODULE_DEVICE_TABLE(i2c, dm355evm_msp_ids);
 399
 400 static struct i2c_driver dm355evm_msp_driver = {
 401         .driver.name    = "dm355evm_msp",
 402         .id_table       = dm355evm_msp_ids,
 403         .probe          = dm355evm_msp_probe,
 404         .remove         = dm355evm_msp_remove,
 405 };
 406
 407 static int __init dm355evm_msp_init(void)
 408 {
 409         return i2c_add_driver(&dm355evm_msp_driver);
 410 }
 411 subsys_initcall(dm355evm_msp_init);
 412
 413 static void __exit dm355evm_msp_exit(void)
 414 {
 415         i2c_del_driver(&dm355evm_msp_driver);
 416 }
 417 module_exit(dm355evm_msp_exit);
 418
 419 MODULE_DESCRIPTION("Interface to MSP430 firmware on DM355EVM");
 420 MODULE_LICENSE("GPL");