/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
 64static 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 */
 73int dm355evm_msp_write(u8 value, u8 reg)
 74{
 75	return i2c_smbus_write_byte_data(msp430, reg, value);
 76}
 77EXPORT_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 */
 85int dm355evm_msp_read(u8 reg)
 86{
 87	return i2c_smbus_read_byte_data(msp430, reg);
 88}
 89EXPORT_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
 99static 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	/*
111	 * Note: EVMDM355_ECP_VA4.pdf suggests that Bit 2 and 4 should be
112	 * checked for card detection. However on the EVM bit 1 and 3 gives
113	 * this status, for 0 and 1 instance respectively. The pdf also
114	 * suggests that Bit 1 and 3 should be checked for write protection.
115	 * However on the EVM bit 2 and 4 gives this status,for 0 and 1
116	 * instance respectively.
117	 */
118	MSP_GPIO(2, SDMMC), MSP_GPIO(1, SDMMC),	/* mmc0 WP, nCD */
119	MSP_GPIO(4, SDMMC), MSP_GPIO(3, SDMMC),	/* mmc1 WP, nCD */
120};
121
122#define MSP_GPIO_REG(offset)	(msp_gpios[(offset)] >> 3)
123#define MSP_GPIO_MASK(offset)	BIT(msp_gpios[(offset)] & 0x07)
124
125static int msp_gpio_in(struct gpio_chip *chip, unsigned offset)
126{
127	switch (MSP_GPIO_REG(offset)) {
128	case DM355EVM_MSP_SWITCH1:
129	case DM355EVM_MSP_SWITCH2:
130	case DM355EVM_MSP_SDMMC:
131		return 0;
132	default:
133		return -EINVAL;
134	}
135}
136
137static u8 msp_led_cache;
138
139static int msp_gpio_get(struct gpio_chip *chip, unsigned offset)
140{
141	int reg, status;
142
143	reg = MSP_GPIO_REG(offset);
144	status = dm355evm_msp_read(reg);
145	if (status < 0)
146		return status;
147	if (reg == DM355EVM_MSP_LED)
148		msp_led_cache = status;
149	return status & MSP_GPIO_MASK(offset);
150}
151
152static int msp_gpio_out(struct gpio_chip *chip, unsigned offset, int value)
153{
154	int mask, bits;
155
156	/* NOTE:  there are some other signals that could be
157	 * packaged as output GPIOs, but they aren't as useful
158	 * as the LEDs ... so for now we don't.
159	 */
160	if (MSP_GPIO_REG(offset) != DM355EVM_MSP_LED)
161		return -EINVAL;
162
163	mask = MSP_GPIO_MASK(offset);
164	bits = msp_led_cache;
165
166	bits &= ~mask;
167	if (value)
168		bits |= mask;
169	msp_led_cache = bits;
170
171	return dm355evm_msp_write(bits, DM355EVM_MSP_LED);
172}
173
174static void msp_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
175{
176	msp_gpio_out(chip, offset, value);
177}
178
179static struct gpio_chip dm355evm_msp_gpio = {
180	.label			= "dm355evm_msp",
181	.owner			= THIS_MODULE,
182	.direction_input	= msp_gpio_in,
183	.get			= msp_gpio_get,
184	.direction_output	= msp_gpio_out,
185	.set			= msp_gpio_set,
186	.base			= -EINVAL,		/* dynamic assignment */
187	.ngpio			= ARRAY_SIZE(msp_gpios),
188	.can_sleep		= true,
189};
190
191/*----------------------------------------------------------------------*/
192
193static struct device *add_child(struct i2c_client *client, const char *name,
194		void *pdata, unsigned pdata_len,
195		bool can_wakeup, int irq)
196{
197	struct platform_device	*pdev;
198	int			status;
199
200	pdev = platform_device_alloc(name, -1);
201	if (!pdev) {
202		dev_dbg(&client->dev, "can't alloc dev\n");
203		status = -ENOMEM;
204		goto err;
205	}
206
207	device_init_wakeup(&pdev->dev, can_wakeup);
208	pdev->dev.parent = &client->dev;
209
210	if (pdata) {
211		status = platform_device_add_data(pdev, pdata, pdata_len);
212		if (status < 0) {
213			dev_dbg(&pdev->dev, "can't add platform_data\n");
214			goto err;
215		}
216	}
217
218	if (irq) {
219		struct resource r = {
220			.start = irq,
221			.flags = IORESOURCE_IRQ,
222		};
223
224		status = platform_device_add_resources(pdev, &r, 1);
225		if (status < 0) {
226			dev_dbg(&pdev->dev, "can't add irq\n");
227			goto err;
228		}
229	}
230
231	status = platform_device_add(pdev);
232
233err:
234	if (status < 0) {
235		platform_device_put(pdev);
236		dev_err(&client->dev, "can't add %s dev\n", name);
237		return ERR_PTR(status);
238	}
239	return &pdev->dev;
240}
241
242static int add_children(struct i2c_client *client)
243{
244	static const struct {
245		int offset;
246		char *label;
247	} config_inputs[] = {
248		/* 8 == right after the LEDs */
249		{ 8 + 0, "sw6_1", },
250		{ 8 + 1, "sw6_2", },
251		{ 8 + 2, "sw6_3", },
252		{ 8 + 3, "sw6_4", },
253		{ 8 + 4, "NTSC/nPAL", },
254	};
255
256	struct device	*child;
257	int		status;
258	int		i;
259
260	/* GPIO-ish stuff */
261	dm355evm_msp_gpio.dev = &client->dev;
262	status = gpiochip_add(&dm355evm_msp_gpio);
263	if (status < 0)
264		return status;
265
266	/* LED output */
267	if (msp_has_leds()) {
268#define GPIO_LED(l)	.name = l, .active_low = true
269		static struct gpio_led evm_leds[] = {
270			{ GPIO_LED("dm355evm::ds14"),
271				.default_trigger = "heartbeat", },
272			{ GPIO_LED("dm355evm::ds15"),
273				.default_trigger = "mmc0", },
274			{ GPIO_LED("dm355evm::ds16"),
275				/* could also be a CE-ATA drive */
276				.default_trigger = "mmc1", },
277			{ GPIO_LED("dm355evm::ds17"),
278				.default_trigger = "nand-disk", },
279			{ GPIO_LED("dm355evm::ds18"), },
280			{ GPIO_LED("dm355evm::ds19"), },
281			{ GPIO_LED("dm355evm::ds20"), },
282			{ GPIO_LED("dm355evm::ds21"), },
283		};
284#undef GPIO_LED
285
286		struct gpio_led_platform_data evm_led_data = {
287			.num_leds	= ARRAY_SIZE(evm_leds),
288			.leds		= evm_leds,
289		};
290
291		for (i = 0; i < ARRAY_SIZE(evm_leds); i++)
292			evm_leds[i].gpio = i + dm355evm_msp_gpio.base;
293
294		/* NOTE:  these are the only fully programmable LEDs
295		 * on the board, since GPIO-61/ds22 (and many signals
296		 * going to DC7) must be used for AEMIF address lines
297		 * unless the top 1 GB of NAND is unused...
298		 */
299		child = add_child(client, "leds-gpio",
300				&evm_led_data, sizeof(evm_led_data),
301				false, 0);
302		if (IS_ERR(child))
303			return PTR_ERR(child);
304	}
305
306	/* configuration inputs */
307	for (i = 0; i < ARRAY_SIZE(config_inputs); i++) {
308		int gpio = dm355evm_msp_gpio.base + config_inputs[i].offset;
309
310		gpio_request(gpio, config_inputs[i].label);
311		gpio_direction_input(gpio);
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
345static 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
355static void dm355evm_power_off(void)
356{
357	dm355evm_command(MSP_COMMAND_POWEROFF);
358}
359
360static int dm355evm_msp_remove(struct i2c_client *client)
361{
362	pm_power_off = NULL;
363	msp430 = NULL;
364	return 0;
365}
366
367static int
368dm355evm_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 */
378	status = dm355evm_msp_read(DM355EVM_MSP_FIRMREV);
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 */
385	status = dm355evm_msp_write(msp_has_tvp() ? 0 : MSP_VIDEO_IMAGER,
386			DM355EVM_MSP_VIDEO_IN);
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
405fail:
406	/* FIXME remove children ... */
407	dm355evm_msp_remove(client);
408	return status;
409}
410
411static const struct i2c_device_id dm355evm_msp_ids[] = {
412	{ "dm355evm_msp", 0 },
413	{ /* end of list */ },
414};
415MODULE_DEVICE_TABLE(i2c, dm355evm_msp_ids);
416
417static 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
424static int __init dm355evm_msp_init(void)
425{
426	return i2c_add_driver(&dm355evm_msp_driver);
427}
428subsys_initcall(dm355evm_msp_init);
429
430static void __exit dm355evm_msp_exit(void)
431{
432	i2c_del_driver(&dm355evm_msp_driver);
433}
434module_exit(dm355evm_msp_exit);
435
436MODULE_DESCRIPTION("Interface to MSP430 firmware on DM355EVM");
437MODULE_LICENSE("GPL");