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 */
dm355evm_msp_write(u8 value,u8 reg)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 */
dm355evm_msp_read(u8 reg)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
msp_gpio_in(struct gpio_chip * chip,unsigned offset)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
msp_gpio_get(struct gpio_chip * chip,unsigned offset)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
msp_gpio_out(struct gpio_chip * chip,unsigned offset,int value)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
msp_gpio_set(struct gpio_chip * chip,unsigned offset,int value)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
add_child(struct i2c_client * client,const char * name,void * pdata,unsigned pdata_len,bool can_wakeup,int irq)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
add_children(struct i2c_client * client)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
dm355evm_command(unsigned command)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
dm355evm_power_off(void)353 static void dm355evm_power_off(void)
354 {
355 dm355evm_command(MSP_COMMAND_POWEROFF);
356 }
357
dm355evm_msp_remove(struct i2c_client * client)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
dm355evm_msp_probe(struct i2c_client * client,const struct i2c_device_id * id)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
dm355evm_msp_init(void)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
dm355evm_msp_exit(void)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");
436
