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