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  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * dm355evm_msp.c - driver for MSP430 firmware on DM355EVM board
  4 *
  5 * Copyright (C) 2008 David Brownell
  6 */
  7
  8#include <linux/init.h>
  9#include <linux/mutex.h>
 10#include <linux/platform_device.h>
 11#include <linux/clk.h>
 12#include <linux/module.h>
 13#include <linux/err.h>
 14#include <linux/gpio.h>
 15#include <linux/gpio/machine.h>
 16#include <linux/leds.h>
 17#include <linux/i2c.h>
 18#include <linux/mfd/dm355evm_msp.h>
 19
 20
 21/*
 22 * The DM355 is a DaVinci chip with video support but no C64+ DSP.  Its
 23 * EVM board has an MSP430 programmed with firmware for various board
 24 * support functions.  This driver exposes some of them directly, and
 25 * supports other drivers (e.g. RTC, input) for more complex access.
 26 *
 27 * Because this firmware is entirely board-specific, this file embeds
 28 * knowledge that would be passed as platform_data in a generic driver.
 29 *
 30 * This driver was tested with firmware revision A4.
 31 */
 32
 33#if IS_ENABLED(CONFIG_INPUT_DM355EVM)
 34#define msp_has_keyboard()	true
 35#else
 36#define msp_has_keyboard()	false
 37#endif
 38
 39#if IS_ENABLED(CONFIG_LEDS_GPIO)
 40#define msp_has_leds()		true
 41#else
 42#define msp_has_leds()		false
 43#endif
 44
 45#if IS_ENABLED(CONFIG_RTC_DRV_DM355EVM)
 46#define msp_has_rtc()		true
 47#else
 48#define msp_has_rtc()		false
 49#endif
 50
 51#if IS_ENABLED(CONFIG_VIDEO_TVP514X)
 52#define msp_has_tvp()		true
 53#else
 54#define msp_has_tvp()		false
 55#endif
 56
 57
 58/*----------------------------------------------------------------------*/
 59
 60/* REVISIT for paranoia's sake, retry reads/writes on error */
 61
 62static struct i2c_client *msp430;
 63
 64/**
 65 * dm355evm_msp_write - Writes a register in dm355evm_msp
 66 * @value: the value to be written
 67 * @reg: register address
 68 *
 69 * Returns result of operation - 0 is success, else negative errno
 70 */
 71int dm355evm_msp_write(u8 value, u8 reg)
 72{
 73	return i2c_smbus_write_byte_data(msp430, reg, value);
 74}
 75EXPORT_SYMBOL(dm355evm_msp_write);
 76
 77/**
 78 * dm355evm_msp_read - Reads a register from dm355evm_msp
 79 * @reg: register address
 80 *
 81 * Returns result of operation - value, or negative errno
 82 */
 83int dm355evm_msp_read(u8 reg)
 84{
 85	return i2c_smbus_read_byte_data(msp430, reg);
 86}
 87EXPORT_SYMBOL(dm355evm_msp_read);
 88
 89/*----------------------------------------------------------------------*/
 90
 91/*
 92 * Many of the msp430 pins are just used as fixed-direction GPIOs.
 93 * We could export a few more of them this way, if we wanted.
 94 */
 95#define MSP_GPIO(bit, reg)	((DM355EVM_MSP_ ## reg) << 3 | (bit))
 96
 97static const u8 msp_gpios[] = {
 98	/* eight leds */
 99	MSP_GPIO(0, LED), MSP_GPIO(1, LED),
100	MSP_GPIO(2, LED), MSP_GPIO(3, LED),
101	MSP_GPIO(4, LED), MSP_GPIO(5, LED),
102	MSP_GPIO(6, LED), MSP_GPIO(7, LED),
103	/* SW6 and the NTSC/nPAL jumper */
104	MSP_GPIO(0, SWITCH1), MSP_GPIO(1, SWITCH1),
105	MSP_GPIO(2, SWITCH1), MSP_GPIO(3, SWITCH1),
106	MSP_GPIO(4, SWITCH1),
107	/* switches on MMC/SD sockets */
108	/*
109	 * Note: EVMDM355_ECP_VA4.pdf suggests that Bit 2 and 4 should be
110	 * checked for card detection. However on the EVM bit 1 and 3 gives
111	 * this status, for 0 and 1 instance respectively. The pdf also
112	 * suggests that Bit 1 and 3 should be checked for write protection.
113	 * However on the EVM bit 2 and 4 gives this status,for 0 and 1
114	 * instance respectively.
115	 */
116	MSP_GPIO(2, SDMMC), MSP_GPIO(1, SDMMC),	/* mmc0 WP, nCD */
117	MSP_GPIO(4, SDMMC), MSP_GPIO(3, SDMMC),	/* mmc1 WP, nCD */
118};
119
120static struct gpio_led evm_leds[] = {
121	{ .name = "dm355evm::ds14",
122	  .default_trigger = "heartbeat", },
123	{ .name = "dm355evm::ds15",
124	  .default_trigger = "mmc0", },
125	{ .name = "dm355evm::ds16",
126	  /* could also be a CE-ATA drive */
127	  .default_trigger = "mmc1", },
128	{ .name = "dm355evm::ds17",
129	  .default_trigger = "nand-disk", },
130	{ .name = "dm355evm::ds18", },
131	{ .name = "dm355evm::ds19", },
132	{ .name = "dm355evm::ds20", },
133	{ .name = "dm355evm::ds21", },
134};
135
136static struct gpio_led_platform_data evm_led_data = {
137	.num_leds	= ARRAY_SIZE(evm_leds),
138	.leds		= evm_leds,
139};
140
141static struct gpiod_lookup_table evm_leds_gpio_table = {
142	.dev_id = "leds-gpio",
143	.table = {
144		/*
145		 * These GPIOs are on the dm355evm_msp
146		 * GPIO chip at index 0..7
147		 */
148		GPIO_LOOKUP_IDX("dm355evm_msp", 0, NULL,
149				0, GPIO_ACTIVE_LOW),
150		GPIO_LOOKUP_IDX("dm355evm_msp", 1, NULL,
151				1, GPIO_ACTIVE_LOW),
152		GPIO_LOOKUP_IDX("dm355evm_msp", 2, NULL,
153				2, GPIO_ACTIVE_LOW),
154		GPIO_LOOKUP_IDX("dm355evm_msp", 3, NULL,
155				3, GPIO_ACTIVE_LOW),
156		GPIO_LOOKUP_IDX("dm355evm_msp", 4, NULL,
157				4, GPIO_ACTIVE_LOW),
158		GPIO_LOOKUP_IDX("dm355evm_msp", 5, NULL,
159				5, GPIO_ACTIVE_LOW),
160		GPIO_LOOKUP_IDX("dm355evm_msp", 6, NULL,
161				6, GPIO_ACTIVE_LOW),
162		GPIO_LOOKUP_IDX("dm355evm_msp", 7, NULL,
163				7, GPIO_ACTIVE_LOW),
164		{ },
165	},
166};
167
168#define MSP_GPIO_REG(offset)	(msp_gpios[(offset)] >> 3)
169#define MSP_GPIO_MASK(offset)	BIT(msp_gpios[(offset)] & 0x07)
170
171static int msp_gpio_in(struct gpio_chip *chip, unsigned offset)
172{
173	switch (MSP_GPIO_REG(offset)) {
174	case DM355EVM_MSP_SWITCH1:
175	case DM355EVM_MSP_SWITCH2:
176	case DM355EVM_MSP_SDMMC:
177		return 0;
178	default:
179		return -EINVAL;
180	}
181}
182
183static u8 msp_led_cache;
184
185static int msp_gpio_get(struct gpio_chip *chip, unsigned offset)
186{
187	int reg, status;
188
189	reg = MSP_GPIO_REG(offset);
190	status = dm355evm_msp_read(reg);
191	if (status < 0)
192		return status;
193	if (reg == DM355EVM_MSP_LED)
194		msp_led_cache = status;
195	return !!(status & MSP_GPIO_MASK(offset));
196}
197
198static int msp_gpio_out(struct gpio_chip *chip, unsigned offset, int value)
199{
200	int mask, bits;
201
202	/* NOTE:  there are some other signals that could be
203	 * packaged as output GPIOs, but they aren't as useful
204	 * as the LEDs ... so for now we don't.
205	 */
206	if (MSP_GPIO_REG(offset) != DM355EVM_MSP_LED)
207		return -EINVAL;
208
209	mask = MSP_GPIO_MASK(offset);
210	bits = msp_led_cache;
211
212	bits &= ~mask;
213	if (value)
214		bits |= mask;
215	msp_led_cache = bits;
216
217	return dm355evm_msp_write(bits, DM355EVM_MSP_LED);
218}
219
220static void msp_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
221{
222	msp_gpio_out(chip, offset, value);
223}
224
225static struct gpio_chip dm355evm_msp_gpio = {
226	.label			= "dm355evm_msp",
227	.owner			= THIS_MODULE,
228	.direction_input	= msp_gpio_in,
229	.get			= msp_gpio_get,
230	.direction_output	= msp_gpio_out,
231	.set			= msp_gpio_set,
232	.base			= -EINVAL,		/* dynamic assignment */
233	.ngpio			= ARRAY_SIZE(msp_gpios),
234	.can_sleep		= true,
235};
236
237/*----------------------------------------------------------------------*/
238
239static struct device *add_child(struct i2c_client *client, const char *name,
240		void *pdata, unsigned pdata_len,
241		bool can_wakeup, int irq)
242{
243	struct platform_device	*pdev;
244	int			status;
245
246	pdev = platform_device_alloc(name, -1);
247	if (!pdev)
248		return ERR_PTR(-ENOMEM);
249
250	device_init_wakeup(&pdev->dev, can_wakeup);
251	pdev->dev.parent = &client->dev;
252
253	if (pdata) {
254		status = platform_device_add_data(pdev, pdata, pdata_len);
255		if (status < 0) {
256			dev_dbg(&pdev->dev, "can't add platform_data\n");
257			goto put_device;
258		}
259	}
260
261	if (irq) {
262		struct resource r = {
263			.start = irq,
264			.flags = IORESOURCE_IRQ,
265		};
266
267		status = platform_device_add_resources(pdev, &r, 1);
268		if (status < 0) {
269			dev_dbg(&pdev->dev, "can't add irq\n");
270			goto put_device;
271		}
272	}
273
274	status = platform_device_add(pdev);
275	if (status)
276		goto put_device;
277
278	return &pdev->dev;
279
280put_device:
281	platform_device_put(pdev);
282	dev_err(&client->dev, "failed to add device %s\n", name);
283	return ERR_PTR(status);
284}
285
286static int add_children(struct i2c_client *client)
287{
288	static const struct {
289		int offset;
290		char *label;
291	} config_inputs[] = {
292		/* 8 == right after the LEDs */
293		{ 8 + 0, "sw6_1", },
294		{ 8 + 1, "sw6_2", },
295		{ 8 + 2, "sw6_3", },
296		{ 8 + 3, "sw6_4", },
297		{ 8 + 4, "NTSC/nPAL", },
298	};
299
300	struct device	*child;
301	int		status;
302	int		i;
303
304	/* GPIO-ish stuff */
305	dm355evm_msp_gpio.parent = &client->dev;
306	status = gpiochip_add_data(&dm355evm_msp_gpio, NULL);
307	if (status < 0)
308		return status;
309
310	/* LED output */
311	if (msp_has_leds()) {
312		gpiod_add_lookup_table(&evm_leds_gpio_table);
313		/* NOTE:  these are the only fully programmable LEDs
314		 * on the board, since GPIO-61/ds22 (and many signals
315		 * going to DC7) must be used for AEMIF address lines
316		 * unless the top 1 GB of NAND is unused...
317		 */
318		child = add_child(client, "leds-gpio",
319				&evm_led_data, sizeof(evm_led_data),
320				false, 0);
321		if (IS_ERR(child))
322			return PTR_ERR(child);
323	}
324
325	/* configuration inputs */
326	for (i = 0; i < ARRAY_SIZE(config_inputs); i++) {
327		int gpio = dm355evm_msp_gpio.base + config_inputs[i].offset;
328
329		gpio_request_one(gpio, GPIOF_IN, config_inputs[i].label);
330
331		/* make it easy for userspace to see these */
332		gpio_export(gpio, false);
333	}
334
335	/* MMC/SD inputs -- right after the last config input */
336	if (dev_get_platdata(&client->dev)) {
337		void (*mmcsd_setup)(unsigned) = dev_get_platdata(&client->dev);
338
339		mmcsd_setup(dm355evm_msp_gpio.base + 8 + 5);
340	}
341
342	/* RTC is a 32 bit counter, no alarm */
343	if (msp_has_rtc()) {
344		child = add_child(client, "rtc-dm355evm",
345				NULL, 0, false, 0);
346		if (IS_ERR(child))
347			return PTR_ERR(child);
348	}
349
350	/* input from buttons and IR remote (uses the IRQ) */
351	if (msp_has_keyboard()) {
352		child = add_child(client, "dm355evm_keys",
353				NULL, 0, true, client->irq);
354		if (IS_ERR(child))
355			return PTR_ERR(child);
356	}
357
358	return 0;
359}
360
361/*----------------------------------------------------------------------*/
362
363static void dm355evm_command(unsigned command)
364{
365	int status;
366
367	status = dm355evm_msp_write(command, DM355EVM_MSP_COMMAND);
368	if (status < 0)
369		dev_err(&msp430->dev, "command %d failure %d\n",
370				command, status);
371}
372
373static void dm355evm_power_off(void)
374{
375	dm355evm_command(MSP_COMMAND_POWEROFF);
376}
377
378static int dm355evm_msp_remove(struct i2c_client *client)
379{
380	pm_power_off = NULL;
381	msp430 = NULL;
382	return 0;
383}
384
385static int
386dm355evm_msp_probe(struct i2c_client *client, const struct i2c_device_id *id)
387{
388	int		status;
389	const char	*video = msp_has_tvp() ? "TVP5146" : "imager";
390
391	if (msp430)
392		return -EBUSY;
393	msp430 = client;
394
395	/* display revision status; doubles as sanity check */
396	status = dm355evm_msp_read(DM355EVM_MSP_FIRMREV);
397	if (status < 0)
398		goto fail;
399	dev_info(&client->dev, "firmware v.%02X, %s as video-in\n",
400			status, video);
401
402	/* mux video input:  either tvp5146 or some external imager */
403	status = dm355evm_msp_write(msp_has_tvp() ? 0 : MSP_VIDEO_IMAGER,
404			DM355EVM_MSP_VIDEO_IN);
405	if (status < 0)
406		dev_warn(&client->dev, "error %d muxing %s as video-in\n",
407			status, video);
408
409	/* init LED cache, and turn off the LEDs */
410	msp_led_cache = 0xff;
411	dm355evm_msp_write(msp_led_cache, DM355EVM_MSP_LED);
412
413	/* export capabilities we support */
414	status = add_children(client);
415	if (status < 0)
416		goto fail;
417
418	/* PM hookup */
419	pm_power_off = dm355evm_power_off;
420
421	return 0;
422
423fail:
424	/* FIXME remove children ... */
425	dm355evm_msp_remove(client);
426	return status;
427}
428
429static const struct i2c_device_id dm355evm_msp_ids[] = {
430	{ "dm355evm_msp", 0 },
431	{ /* end of list */ },
432};
433MODULE_DEVICE_TABLE(i2c, dm355evm_msp_ids);
434
435static struct i2c_driver dm355evm_msp_driver = {
436	.driver.name	= "dm355evm_msp",
437	.id_table	= dm355evm_msp_ids,
438	.probe		= dm355evm_msp_probe,
439	.remove		= dm355evm_msp_remove,
440};
441
442static int __init dm355evm_msp_init(void)
443{
444	return i2c_add_driver(&dm355evm_msp_driver);
445}
446subsys_initcall(dm355evm_msp_init);
447
448static void __exit dm355evm_msp_exit(void)
449{
450	i2c_del_driver(&dm355evm_msp_driver);
451}
452module_exit(dm355evm_msp_exit);
453
454MODULE_DESCRIPTION("Interface to MSP430 firmware on DM355EVM");
455MODULE_LICENSE("GPL");