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
65static 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 */
74int dm355evm_msp_write(u8 value, u8 reg)
75{
76	return i2c_smbus_write_byte_data(msp430, reg, value);
77}
78EXPORT_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 */
86int dm355evm_msp_read(u8 reg)
87{
88	return i2c_smbus_read_byte_data(msp430, reg);
89}
90EXPORT_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
100static 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
126static 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
138static u8 msp_led_cache;
139
140static 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
153static 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
175static void msp_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
176{
177	msp_gpio_out(chip, offset, value);
178}
179
180static 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
194static 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
234err:
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
243static 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 (dev_get_platdata(&client->dev)) {
319		void (*mmcsd_setup)(unsigned) = dev_get_platdata(&client->dev);
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");
438