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dm355evm_msp.c
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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/i2c/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 defined(CONFIG_INPUT_DM355EVM) || defined(CONFIG_INPUT_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 
75 {
76  return i2c_smbus_write_byte_data(msp430, reg, value);
77 }
79 
87 {
88  return i2c_smbus_read_byte_data(msp430, reg);
89 }
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)) {
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  dev_dbg(&client->dev, "can't alloc dev\n");
204  status = -ENOMEM;
205  goto err;
206  }
207 
208  device_init_wakeup(&pdev->dev, can_wakeup);
209  pdev->dev.parent = &client->dev;
210 
211  if (pdata) {
212  status = platform_device_add_data(pdev, pdata, pdata_len);
213  if (status < 0) {
214  dev_dbg(&pdev->dev, "can't add platform_data\n");
215  goto err;
216  }
217  }
218 
219  if (irq) {
220  struct resource r = {
221  .start = irq,
222  .flags = IORESOURCE_IRQ,
223  };
224 
225  status = platform_device_add_resources(pdev, &r, 1);
226  if (status < 0) {
227  dev_dbg(&pdev->dev, "can't add irq\n");
228  goto err;
229  }
230  }
231 
232  status = platform_device_add(pdev);
233 
234 err:
235  if (status < 0) {
236  platform_device_put(pdev);
237  dev_err(&client->dev, "can't add %s dev\n", name);
238  return ERR_PTR(status);
239  }
240  return &pdev->dev;
241 }
242 
243 static int add_children(struct i2c_client *client)
244 {
245  static const struct {
246  int offset;
247  char *label;
248  } config_inputs[] = {
249  /* 8 == right after the LEDs */
250  { 8 + 0, "sw6_1", },
251  { 8 + 1, "sw6_2", },
252  { 8 + 2, "sw6_3", },
253  { 8 + 3, "sw6_4", },
254  { 8 + 4, "NTSC/nPAL", },
255  };
256 
257  struct device *child;
258  int status;
259  int i;
260 
261  /* GPIO-ish stuff */
262  dm355evm_msp_gpio.dev = &client->dev;
263  status = gpiochip_add(&dm355evm_msp_gpio);
264  if (status < 0)
265  return status;
266 
267  /* LED output */
268  if (msp_has_leds()) {
269 #define GPIO_LED(l) .name = l, .active_low = true
270  static struct gpio_led evm_leds[] = {
271  { GPIO_LED("dm355evm::ds14"),
272  .default_trigger = "heartbeat", },
273  { GPIO_LED("dm355evm::ds15"),
274  .default_trigger = "mmc0", },
275  { GPIO_LED("dm355evm::ds16"),
276  /* could also be a CE-ATA drive */
277  .default_trigger = "mmc1", },
278  { GPIO_LED("dm355evm::ds17"),
279  .default_trigger = "nand-disk", },
280  { GPIO_LED("dm355evm::ds18"), },
281  { GPIO_LED("dm355evm::ds19"), },
282  { GPIO_LED("dm355evm::ds20"), },
283  { GPIO_LED("dm355evm::ds21"), },
284  };
285 #undef GPIO_LED
286 
287  struct gpio_led_platform_data evm_led_data = {
288  .num_leds = ARRAY_SIZE(evm_leds),
289  .leds = evm_leds,
290  };
291 
292  for (i = 0; i < ARRAY_SIZE(evm_leds); i++)
293  evm_leds[i].gpio = i + dm355evm_msp_gpio.base;
294 
295  /* NOTE: these are the only fully programmable LEDs
296  * on the board, since GPIO-61/ds22 (and many signals
297  * going to DC7) must be used for AEMIF address lines
298  * unless the top 1 GB of NAND is unused...
299  */
300  child = add_child(client, "leds-gpio",
301  &evm_led_data, sizeof(evm_led_data),
302  false, 0);
303  if (IS_ERR(child))
304  return PTR_ERR(child);
305  }
306 
307  /* configuration inputs */
308  for (i = 0; i < ARRAY_SIZE(config_inputs); i++) {
309  int gpio = dm355evm_msp_gpio.base + config_inputs[i].offset;
310 
311  gpio_request_one(gpio, GPIOF_IN, config_inputs[i].label);
312 
313  /* make it easy for userspace to see these */
314  gpio_export(gpio, false);
315  }
316 
317  /* MMC/SD inputs -- right after the last config input */
318  if (client->dev.platform_data) {
319  void (*mmcsd_setup)(unsigned) = client->dev.platform_data;
320 
321  mmcsd_setup(dm355evm_msp_gpio.base + 8 + 5);
322  }
323 
324  /* RTC is a 32 bit counter, no alarm */
325  if (msp_has_rtc()) {
326  child = add_child(client, "rtc-dm355evm",
327  NULL, 0, false, 0);
328  if (IS_ERR(child))
329  return PTR_ERR(child);
330  }
331 
332  /* input from buttons and IR remote (uses the IRQ) */
333  if (msp_has_keyboard()) {
334  child = add_child(client, "dm355evm_keys",
335  NULL, 0, true, client->irq);
336  if (IS_ERR(child))
337  return PTR_ERR(child);
338  }
339 
340  return 0;
341 }
342 
343 /*----------------------------------------------------------------------*/
344 
345 static void dm355evm_command(unsigned command)
346 {
347  int status;
348 
349  status = dm355evm_msp_write(command, DM355EVM_MSP_COMMAND);
350  if (status < 0)
351  dev_err(&msp430->dev, "command %d failure %d\n",
352  command, status);
353 }
354 
355 static void dm355evm_power_off(void)
356 {
357  dm355evm_command(MSP_COMMAND_POWEROFF);
358 }
359 
360 static int dm355evm_msp_remove(struct i2c_client *client)
361 {
362  pm_power_off = NULL;
363  msp430 = NULL;
364  return 0;
365 }
366 
367 static int
368 dm355evm_msp_probe(struct i2c_client *client, const struct i2c_device_id *id)
369 {
370  int status;
371  const char *video = msp_has_tvp() ? "TVP5146" : "imager";
372 
373  if (msp430)
374  return -EBUSY;
375  msp430 = client;
376 
377  /* display revision status; doubles as sanity check */
379  if (status < 0)
380  goto fail;
381  dev_info(&client->dev, "firmware v.%02X, %s as video-in\n",
382  status, video);
383 
384  /* mux video input: either tvp5146 or some external imager */
387  if (status < 0)
388  dev_warn(&client->dev, "error %d muxing %s as video-in\n",
389  status, video);
390 
391  /* init LED cache, and turn off the LEDs */
392  msp_led_cache = 0xff;
393  dm355evm_msp_write(msp_led_cache, DM355EVM_MSP_LED);
394 
395  /* export capabilities we support */
396  status = add_children(client);
397  if (status < 0)
398  goto fail;
399 
400  /* PM hookup */
401  pm_power_off = dm355evm_power_off;
402 
403  return 0;
404 
405 fail:
406  /* FIXME remove children ... */
407  dm355evm_msp_remove(client);
408  return status;
409 }
410 
411 static const struct i2c_device_id dm355evm_msp_ids[] = {
412  { "dm355evm_msp", 0 },
413  { /* end of list */ },
414 };
415 MODULE_DEVICE_TABLE(i2c, dm355evm_msp_ids);
416 
417 static struct i2c_driver dm355evm_msp_driver = {
418  .driver.name = "dm355evm_msp",
419  .id_table = dm355evm_msp_ids,
420  .probe = dm355evm_msp_probe,
421  .remove = dm355evm_msp_remove,
422 };
423 
424 static int __init dm355evm_msp_init(void)
425 {
426  return i2c_add_driver(&dm355evm_msp_driver);
427 }
428 subsys_initcall(dm355evm_msp_init);
429 
430 static void __exit dm355evm_msp_exit(void)
431 {
432  i2c_del_driver(&dm355evm_msp_driver);
433 }
434 module_exit(dm355evm_msp_exit);
435 
436 MODULE_DESCRIPTION("Interface to MSP430 firmware on DM355EVM");
437 MODULE_LICENSE("GPL");