xref: /openbmc/linux/drivers/mfd/ipaq-micro.c (revision 4f6cce39)
1 /*
2  * Compaq iPAQ h3xxx Atmel microcontroller companion support
3  *
4  * This is an Atmel AT90LS8535 with a special flashed-in firmware that
5  * implements the special protocol used by this driver.
6  *
7  * based on previous kernel 2.4 version by Andrew Christian
8  * Author : Alessandro Gardich <gremlin@gremlin.it>
9  * Author : Dmitry Artamonow <mad_soft@inbox.ru>
10  * Author : Linus Walleij <linus.walleij@linaro.org>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License version 2 as
14  * published by the Free Software Foundation.
15  */
16 
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
20 #include <linux/pm.h>
21 #include <linux/delay.h>
22 #include <linux/device.h>
23 #include <linux/platform_device.h>
24 #include <linux/io.h>
25 #include <linux/mfd/core.h>
26 #include <linux/mfd/ipaq-micro.h>
27 #include <linux/string.h>
28 #include <linux/random.h>
29 #include <linux/slab.h>
30 #include <linux/list.h>
31 
32 #include <mach/hardware.h>
33 
34 static void ipaq_micro_trigger_tx(struct ipaq_micro *micro)
35 {
36 	struct ipaq_micro_txdev *tx = &micro->tx;
37 	struct ipaq_micro_msg *msg = micro->msg;
38 	int i, bp;
39 	u8 checksum;
40 	u32 val;
41 
42 	bp = 0;
43 	tx->buf[bp++] = CHAR_SOF;
44 
45 	checksum = ((msg->id & 0x0f) << 4) | (msg->tx_len & 0x0f);
46 	tx->buf[bp++] = checksum;
47 
48 	for (i = 0; i < msg->tx_len; i++) {
49 		tx->buf[bp++] = msg->tx_data[i];
50 		checksum += msg->tx_data[i];
51 	}
52 
53 	tx->buf[bp++] = checksum;
54 	tx->len = bp;
55 	tx->index = 0;
56 	print_hex_dump_debug("data: ", DUMP_PREFIX_OFFSET, 16, 1,
57 			     tx->buf, tx->len, true);
58 
59 	/* Enable interrupt */
60 	val = readl(micro->base + UTCR3);
61 	val |= UTCR3_TIE;
62 	writel(val, micro->base + UTCR3);
63 }
64 
65 int ipaq_micro_tx_msg(struct ipaq_micro *micro, struct ipaq_micro_msg *msg)
66 {
67 	unsigned long flags;
68 
69 	dev_dbg(micro->dev, "TX msg: %02x, %d bytes\n", msg->id, msg->tx_len);
70 
71 	spin_lock_irqsave(&micro->lock, flags);
72 	if (micro->msg) {
73 		list_add_tail(&msg->node, &micro->queue);
74 		spin_unlock_irqrestore(&micro->lock, flags);
75 		return 0;
76 	}
77 	micro->msg = msg;
78 	ipaq_micro_trigger_tx(micro);
79 	spin_unlock_irqrestore(&micro->lock, flags);
80 	return 0;
81 }
82 EXPORT_SYMBOL(ipaq_micro_tx_msg);
83 
84 static void micro_rx_msg(struct ipaq_micro *micro, u8 id, int len, u8 *data)
85 {
86 	int i;
87 
88 	dev_dbg(micro->dev, "RX msg: %02x, %d bytes\n", id, len);
89 
90 	spin_lock(&micro->lock);
91 	switch (id) {
92 	case MSG_VERSION:
93 	case MSG_EEPROM_READ:
94 	case MSG_EEPROM_WRITE:
95 	case MSG_BACKLIGHT:
96 	case MSG_NOTIFY_LED:
97 	case MSG_THERMAL_SENSOR:
98 	case MSG_BATTERY:
99 		/* Handle synchronous messages */
100 		if (micro->msg && micro->msg->id == id) {
101 			struct ipaq_micro_msg *msg = micro->msg;
102 
103 			memcpy(msg->rx_data, data, len);
104 			msg->rx_len = len;
105 			complete(&micro->msg->ack);
106 			if (!list_empty(&micro->queue)) {
107 				micro->msg = list_entry(micro->queue.next,
108 							struct ipaq_micro_msg,
109 							node);
110 				list_del_init(&micro->msg->node);
111 				ipaq_micro_trigger_tx(micro);
112 			} else
113 				micro->msg = NULL;
114 			dev_dbg(micro->dev, "OK RX message 0x%02x\n", id);
115 		} else {
116 			dev_err(micro->dev,
117 				"out of band RX message 0x%02x\n", id);
118 			if (!micro->msg)
119 				dev_info(micro->dev, "no message queued\n");
120 			else
121 				dev_info(micro->dev, "expected message %02x\n",
122 					 micro->msg->id);
123 		}
124 		break;
125 	case MSG_KEYBOARD:
126 		if (micro->key)
127 			micro->key(micro->key_data, len, data);
128 		else
129 			dev_dbg(micro->dev, "key message ignored, no handle\n");
130 		break;
131 	case MSG_TOUCHSCREEN:
132 		if (micro->ts)
133 			micro->ts(micro->ts_data, len, data);
134 		else
135 			dev_dbg(micro->dev, "touchscreen message ignored, no handle\n");
136 		break;
137 	default:
138 		dev_err(micro->dev,
139 			"unknown msg %d [%d] ", id, len);
140 		for (i = 0; i < len; ++i)
141 			pr_cont("0x%02x ", data[i]);
142 		pr_cont("\n");
143 	}
144 	spin_unlock(&micro->lock);
145 }
146 
147 static void micro_process_char(struct ipaq_micro *micro, u8 ch)
148 {
149 	struct ipaq_micro_rxdev *rx = &micro->rx;
150 
151 	switch (rx->state) {
152 	case STATE_SOF:	/* Looking for SOF */
153 		if (ch == CHAR_SOF)
154 			rx->state = STATE_ID; /* Next byte is the id and len */
155 		break;
156 	case STATE_ID: /* Looking for id and len byte */
157 		rx->id = (ch & 0xf0) >> 4;
158 		rx->len = (ch & 0x0f);
159 		rx->index = 0;
160 		rx->chksum = ch;
161 		rx->state = (rx->len > 0) ? STATE_DATA : STATE_CHKSUM;
162 		break;
163 	case STATE_DATA: /* Looking for 'len' data bytes */
164 		rx->chksum += ch;
165 		rx->buf[rx->index] = ch;
166 		if (++rx->index == rx->len)
167 			rx->state = STATE_CHKSUM;
168 		break;
169 	case STATE_CHKSUM: /* Looking for the checksum */
170 		if (ch == rx->chksum)
171 			micro_rx_msg(micro, rx->id, rx->len, rx->buf);
172 		rx->state = STATE_SOF;
173 		break;
174 	}
175 }
176 
177 static void micro_rx_chars(struct ipaq_micro *micro)
178 {
179 	u32 status, ch;
180 
181 	while ((status = readl(micro->base + UTSR1)) & UTSR1_RNE) {
182 		ch = readl(micro->base + UTDR);
183 		if (status & UTSR1_PRE)
184 			dev_err(micro->dev, "rx: parity error\n");
185 		else if (status & UTSR1_FRE)
186 			dev_err(micro->dev, "rx: framing error\n");
187 		else if (status & UTSR1_ROR)
188 			dev_err(micro->dev, "rx: overrun error\n");
189 		micro_process_char(micro, ch);
190 	}
191 }
192 
193 static void ipaq_micro_get_version(struct ipaq_micro *micro)
194 {
195 	struct ipaq_micro_msg msg = {
196 		.id = MSG_VERSION,
197 	};
198 
199 	ipaq_micro_tx_msg_sync(micro, &msg);
200 	if (msg.rx_len == 4) {
201 		memcpy(micro->version, msg.rx_data, 4);
202 		micro->version[4] = '\0';
203 	} else if (msg.rx_len == 9) {
204 		memcpy(micro->version, msg.rx_data, 4);
205 		micro->version[4] = '\0';
206 		/* Bytes 4-7 are "pack", byte 8 is "boot type" */
207 	} else {
208 		dev_err(micro->dev,
209 			"illegal version message %d bytes\n", msg.rx_len);
210 	}
211 }
212 
213 static void ipaq_micro_eeprom_read(struct ipaq_micro *micro,
214 				   u8 address, u8 len, u8 *data)
215 {
216 	struct ipaq_micro_msg msg = {
217 		.id = MSG_EEPROM_READ,
218 	};
219 	u8 i;
220 
221 	for (i = 0; i < len; i++) {
222 		msg.tx_data[0] = address + i;
223 		msg.tx_data[1] = 1;
224 		msg.tx_len = 2;
225 		ipaq_micro_tx_msg_sync(micro, &msg);
226 		memcpy(data + (i * 2), msg.rx_data, 2);
227 	}
228 }
229 
230 static char *ipaq_micro_str(u8 *wchar, u8 len)
231 {
232 	char retstr[256];
233 	u8 i;
234 
235 	for (i = 0; i < len / 2; i++)
236 		retstr[i] = wchar[i * 2];
237 	return kstrdup(retstr, GFP_KERNEL);
238 }
239 
240 static u16 ipaq_micro_to_u16(u8 *data)
241 {
242 	return data[1] << 8 | data[0];
243 }
244 
245 static void __init ipaq_micro_eeprom_dump(struct ipaq_micro *micro)
246 {
247 	u8 dump[256];
248 	char *str;
249 
250 	ipaq_micro_eeprom_read(micro, 0, 128, dump);
251 	str = ipaq_micro_str(dump, 10);
252 	if (str) {
253 		dev_info(micro->dev, "HW version %s\n", str);
254 		kfree(str);
255 	}
256 	str = ipaq_micro_str(dump+10, 40);
257 	if (str) {
258 		dev_info(micro->dev, "serial number: %s\n", str);
259 		/* Feed the random pool with this */
260 		add_device_randomness(str, strlen(str));
261 		kfree(str);
262 	}
263 	str = ipaq_micro_str(dump+50, 20);
264 	if (str) {
265 		dev_info(micro->dev, "module ID: %s\n", str);
266 		kfree(str);
267 	}
268 	str = ipaq_micro_str(dump+70, 10);
269 	if (str) {
270 		dev_info(micro->dev, "product revision: %s\n", str);
271 		kfree(str);
272 	}
273 	dev_info(micro->dev, "product ID: %u\n", ipaq_micro_to_u16(dump+80));
274 	dev_info(micro->dev, "frame rate: %u fps\n",
275 		 ipaq_micro_to_u16(dump+82));
276 	dev_info(micro->dev, "page mode: %u\n", ipaq_micro_to_u16(dump+84));
277 	dev_info(micro->dev, "country ID: %u\n", ipaq_micro_to_u16(dump+86));
278 	dev_info(micro->dev, "color display: %s\n",
279 		 ipaq_micro_to_u16(dump+88) ? "yes" : "no");
280 	dev_info(micro->dev, "ROM size: %u MiB\n", ipaq_micro_to_u16(dump+90));
281 	dev_info(micro->dev, "RAM size: %u KiB\n", ipaq_micro_to_u16(dump+92));
282 	dev_info(micro->dev, "screen: %u x %u\n",
283 		 ipaq_micro_to_u16(dump+94), ipaq_micro_to_u16(dump+96));
284 	print_hex_dump_debug("eeprom: ", DUMP_PREFIX_OFFSET, 16, 1,
285 			     dump, 256, true);
286 
287 }
288 
289 static void micro_tx_chars(struct ipaq_micro *micro)
290 {
291 	struct ipaq_micro_txdev *tx = &micro->tx;
292 	u32 val;
293 
294 	while ((tx->index < tx->len) &&
295 	       (readl(micro->base + UTSR1) & UTSR1_TNF)) {
296 		writel(tx->buf[tx->index], micro->base + UTDR);
297 		tx->index++;
298 	}
299 
300 	/* Stop interrupts */
301 	val = readl(micro->base + UTCR3);
302 	val &= ~UTCR3_TIE;
303 	writel(val, micro->base + UTCR3);
304 }
305 
306 static void micro_reset_comm(struct ipaq_micro *micro)
307 {
308 	struct ipaq_micro_rxdev *rx = &micro->rx;
309 	u32 val;
310 
311 	if (micro->msg)
312 		complete(&micro->msg->ack);
313 
314 	/* Initialize Serial channel protocol frame */
315 	rx->state = STATE_SOF;  /* Reset the state machine */
316 
317 	/* Set up interrupts */
318 	writel(0x01, micro->sdlc + 0x0); /* Select UART mode */
319 
320 	/* Clean up CR3 */
321 	writel(0x0, micro->base + UTCR3);
322 
323 	/* Format: 8N1 */
324 	writel(UTCR0_8BitData | UTCR0_1StpBit, micro->base + UTCR0);
325 
326 	/* Baud rate: 115200 */
327 	writel(0x0, micro->base + UTCR1);
328 	writel(0x1, micro->base + UTCR2);
329 
330 	/* Clear SR0 */
331 	writel(0xff, micro->base + UTSR0);
332 
333 	/* Enable RX int, disable TX int */
334 	writel(UTCR3_TXE | UTCR3_RXE | UTCR3_RIE, micro->base + UTCR3);
335 	val = readl(micro->base + UTCR3);
336 	val &= ~UTCR3_TIE;
337 	writel(val, micro->base + UTCR3);
338 }
339 
340 static irqreturn_t micro_serial_isr(int irq, void *dev_id)
341 {
342 	struct ipaq_micro *micro = dev_id;
343 	struct ipaq_micro_txdev *tx = &micro->tx;
344 	u32 status;
345 
346 	status = readl(micro->base + UTSR0);
347 	do {
348 		if (status & (UTSR0_RID | UTSR0_RFS)) {
349 			if (status & UTSR0_RID)
350 				/* Clear the Receiver IDLE bit */
351 				writel(UTSR0_RID, micro->base + UTSR0);
352 			micro_rx_chars(micro);
353 		}
354 
355 		/* Clear break bits */
356 		if (status & (UTSR0_RBB | UTSR0_REB))
357 			writel(status & (UTSR0_RBB | UTSR0_REB),
358 			       micro->base + UTSR0);
359 
360 		if (status & UTSR0_TFS)
361 			micro_tx_chars(micro);
362 
363 		status = readl(micro->base + UTSR0);
364 
365 	} while (((tx->index < tx->len) && (status & UTSR0_TFS)) ||
366 		 (status & (UTSR0_RFS | UTSR0_RID)));
367 
368 	return IRQ_HANDLED;
369 }
370 
371 static const struct mfd_cell micro_cells[] = {
372 	{ .name = "ipaq-micro-backlight", },
373 	{ .name = "ipaq-micro-battery", },
374 	{ .name = "ipaq-micro-keys", },
375 	{ .name = "ipaq-micro-ts", },
376 	{ .name = "ipaq-micro-leds", },
377 };
378 
379 static int __maybe_unused micro_resume(struct device *dev)
380 {
381 	struct ipaq_micro *micro = dev_get_drvdata(dev);
382 
383 	micro_reset_comm(micro);
384 	mdelay(10);
385 
386 	return 0;
387 }
388 
389 static int __init micro_probe(struct platform_device *pdev)
390 {
391 	struct ipaq_micro *micro;
392 	struct resource *res;
393 	int ret;
394 	int irq;
395 
396 	micro = devm_kzalloc(&pdev->dev, sizeof(*micro), GFP_KERNEL);
397 	if (!micro)
398 		return -ENOMEM;
399 
400 	micro->dev = &pdev->dev;
401 
402 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
403 	if (!res)
404 		return -EINVAL;
405 
406 	micro->base = devm_ioremap_resource(&pdev->dev, res);
407 	if (IS_ERR(micro->base))
408 		return PTR_ERR(micro->base);
409 
410 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
411 	if (!res)
412 		return -EINVAL;
413 
414 	micro->sdlc = devm_ioremap_resource(&pdev->dev, res);
415 	if (IS_ERR(micro->sdlc))
416 		return PTR_ERR(micro->sdlc);
417 
418 	micro_reset_comm(micro);
419 
420 	irq = platform_get_irq(pdev, 0);
421 	if (!irq)
422 		return -EINVAL;
423 	ret = devm_request_irq(&pdev->dev, irq, micro_serial_isr,
424 			       IRQF_SHARED, "ipaq-micro",
425 			       micro);
426 	if (ret) {
427 		dev_err(&pdev->dev, "unable to grab serial port IRQ\n");
428 		return ret;
429 	} else
430 		dev_info(&pdev->dev, "grabbed serial port IRQ\n");
431 
432 	spin_lock_init(&micro->lock);
433 	INIT_LIST_HEAD(&micro->queue);
434 	platform_set_drvdata(pdev, micro);
435 
436 	ret = mfd_add_devices(&pdev->dev, pdev->id, micro_cells,
437 			      ARRAY_SIZE(micro_cells), NULL, 0, NULL);
438 	if (ret) {
439 		dev_err(&pdev->dev, "error adding MFD cells");
440 		return ret;
441 	}
442 
443 	/* Check version */
444 	ipaq_micro_get_version(micro);
445 	dev_info(&pdev->dev, "Atmel micro ASIC version %s\n", micro->version);
446 	ipaq_micro_eeprom_dump(micro);
447 
448 	return 0;
449 }
450 
451 static const struct dev_pm_ops micro_dev_pm_ops = {
452 	SET_SYSTEM_SLEEP_PM_OPS(NULL, micro_resume)
453 };
454 
455 static struct platform_driver micro_device_driver = {
456 	.driver   = {
457 		.name	= "ipaq-h3xxx-micro",
458 		.pm	= &micro_dev_pm_ops,
459 		.suppress_bind_attrs = true,
460 	},
461 };
462 builtin_platform_driver_probe(micro_device_driver, micro_probe);
463