xref: /openbmc/linux/drivers/mfd/ipaq-micro.c (revision 82e6fdd6)
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 
57 	/* Enable interrupt */
58 	val = readl(micro->base + UTCR3);
59 	val |= UTCR3_TIE;
60 	writel(val, micro->base + UTCR3);
61 }
62 
63 int ipaq_micro_tx_msg(struct ipaq_micro *micro, struct ipaq_micro_msg *msg)
64 {
65 	unsigned long flags;
66 
67 	dev_dbg(micro->dev, "TX msg: %02x, %d bytes\n", msg->id, msg->tx_len);
68 
69 	spin_lock_irqsave(&micro->lock, flags);
70 	if (micro->msg) {
71 		list_add_tail(&msg->node, &micro->queue);
72 		spin_unlock_irqrestore(&micro->lock, flags);
73 		return 0;
74 	}
75 	micro->msg = msg;
76 	ipaq_micro_trigger_tx(micro);
77 	spin_unlock_irqrestore(&micro->lock, flags);
78 	return 0;
79 }
80 EXPORT_SYMBOL(ipaq_micro_tx_msg);
81 
82 static void micro_rx_msg(struct ipaq_micro *micro, u8 id, int len, u8 *data)
83 {
84 	int i;
85 
86 	dev_dbg(micro->dev, "RX msg: %02x, %d bytes\n", id, len);
87 
88 	spin_lock(&micro->lock);
89 	switch (id) {
90 	case MSG_VERSION:
91 	case MSG_EEPROM_READ:
92 	case MSG_EEPROM_WRITE:
93 	case MSG_BACKLIGHT:
94 	case MSG_NOTIFY_LED:
95 	case MSG_THERMAL_SENSOR:
96 	case MSG_BATTERY:
97 		/* Handle synchronous messages */
98 		if (micro->msg && micro->msg->id == id) {
99 			struct ipaq_micro_msg *msg = micro->msg;
100 
101 			memcpy(msg->rx_data, data, len);
102 			msg->rx_len = len;
103 			complete(&micro->msg->ack);
104 			if (!list_empty(&micro->queue)) {
105 				micro->msg = list_entry(micro->queue.next,
106 							struct ipaq_micro_msg,
107 							node);
108 				list_del_init(&micro->msg->node);
109 				ipaq_micro_trigger_tx(micro);
110 			} else
111 				micro->msg = NULL;
112 			dev_dbg(micro->dev, "OK RX message 0x%02x\n", id);
113 		} else {
114 			dev_err(micro->dev,
115 				"out of band RX message 0x%02x\n", id);
116 			if (!micro->msg)
117 				dev_info(micro->dev, "no message queued\n");
118 			else
119 				dev_info(micro->dev, "expected message %02x\n",
120 					 micro->msg->id);
121 		}
122 		break;
123 	case MSG_KEYBOARD:
124 		if (micro->key)
125 			micro->key(micro->key_data, len, data);
126 		else
127 			dev_dbg(micro->dev, "key message ignored, no handle\n");
128 		break;
129 	case MSG_TOUCHSCREEN:
130 		if (micro->ts)
131 			micro->ts(micro->ts_data, len, data);
132 		else
133 			dev_dbg(micro->dev, "touchscreen message ignored, no handle\n");
134 		break;
135 	default:
136 		dev_err(micro->dev,
137 			"unknown msg %d [%d] ", id, len);
138 		for (i = 0; i < len; ++i)
139 			pr_cont("0x%02x ", data[i]);
140 		pr_cont("\n");
141 	}
142 	spin_unlock(&micro->lock);
143 }
144 
145 static void micro_process_char(struct ipaq_micro *micro, u8 ch)
146 {
147 	struct ipaq_micro_rxdev *rx = &micro->rx;
148 
149 	switch (rx->state) {
150 	case STATE_SOF:	/* Looking for SOF */
151 		if (ch == CHAR_SOF)
152 			rx->state = STATE_ID; /* Next byte is the id and len */
153 		break;
154 	case STATE_ID: /* Looking for id and len byte */
155 		rx->id = (ch & 0xf0) >> 4;
156 		rx->len = (ch & 0x0f);
157 		rx->index = 0;
158 		rx->chksum = ch;
159 		rx->state = (rx->len > 0) ? STATE_DATA : STATE_CHKSUM;
160 		break;
161 	case STATE_DATA: /* Looking for 'len' data bytes */
162 		rx->chksum += ch;
163 		rx->buf[rx->index] = ch;
164 		if (++rx->index == rx->len)
165 			rx->state = STATE_CHKSUM;
166 		break;
167 	case STATE_CHKSUM: /* Looking for the checksum */
168 		if (ch == rx->chksum)
169 			micro_rx_msg(micro, rx->id, rx->len, rx->buf);
170 		rx->state = STATE_SOF;
171 		break;
172 	}
173 }
174 
175 static void micro_rx_chars(struct ipaq_micro *micro)
176 {
177 	u32 status, ch;
178 
179 	while ((status = readl(micro->base + UTSR1)) & UTSR1_RNE) {
180 		ch = readl(micro->base + UTDR);
181 		if (status & UTSR1_PRE)
182 			dev_err(micro->dev, "rx: parity error\n");
183 		else if (status & UTSR1_FRE)
184 			dev_err(micro->dev, "rx: framing error\n");
185 		else if (status & UTSR1_ROR)
186 			dev_err(micro->dev, "rx: overrun error\n");
187 		micro_process_char(micro, ch);
188 	}
189 }
190 
191 static void ipaq_micro_get_version(struct ipaq_micro *micro)
192 {
193 	struct ipaq_micro_msg msg = {
194 		.id = MSG_VERSION,
195 	};
196 
197 	ipaq_micro_tx_msg_sync(micro, &msg);
198 	if (msg.rx_len == 4) {
199 		memcpy(micro->version, msg.rx_data, 4);
200 		micro->version[4] = '\0';
201 	} else if (msg.rx_len == 9) {
202 		memcpy(micro->version, msg.rx_data, 4);
203 		micro->version[4] = '\0';
204 		/* Bytes 4-7 are "pack", byte 8 is "boot type" */
205 	} else {
206 		dev_err(micro->dev,
207 			"illegal version message %d bytes\n", msg.rx_len);
208 	}
209 }
210 
211 static void ipaq_micro_eeprom_read(struct ipaq_micro *micro,
212 				   u8 address, u8 len, u8 *data)
213 {
214 	struct ipaq_micro_msg msg = {
215 		.id = MSG_EEPROM_READ,
216 	};
217 	u8 i;
218 
219 	for (i = 0; i < len; i++) {
220 		msg.tx_data[0] = address + i;
221 		msg.tx_data[1] = 1;
222 		msg.tx_len = 2;
223 		ipaq_micro_tx_msg_sync(micro, &msg);
224 		memcpy(data + (i * 2), msg.rx_data, 2);
225 	}
226 }
227 
228 static char *ipaq_micro_str(u8 *wchar, u8 len)
229 {
230 	char retstr[256];
231 	u8 i;
232 
233 	for (i = 0; i < len / 2; i++)
234 		retstr[i] = wchar[i * 2];
235 	return kstrdup(retstr, GFP_KERNEL);
236 }
237 
238 static u16 ipaq_micro_to_u16(u8 *data)
239 {
240 	return data[1] << 8 | data[0];
241 }
242 
243 static void __init ipaq_micro_eeprom_dump(struct ipaq_micro *micro)
244 {
245 	u8 dump[256];
246 	char *str;
247 
248 	ipaq_micro_eeprom_read(micro, 0, 128, dump);
249 	str = ipaq_micro_str(dump, 10);
250 	if (str) {
251 		dev_info(micro->dev, "HW version %s\n", str);
252 		kfree(str);
253 	}
254 	str = ipaq_micro_str(dump+10, 40);
255 	if (str) {
256 		dev_info(micro->dev, "serial number: %s\n", str);
257 		/* Feed the random pool with this */
258 		add_device_randomness(str, strlen(str));
259 		kfree(str);
260 	}
261 	str = ipaq_micro_str(dump+50, 20);
262 	if (str) {
263 		dev_info(micro->dev, "module ID: %s\n", str);
264 		kfree(str);
265 	}
266 	str = ipaq_micro_str(dump+70, 10);
267 	if (str) {
268 		dev_info(micro->dev, "product revision: %s\n", str);
269 		kfree(str);
270 	}
271 	dev_info(micro->dev, "product ID: %u\n", ipaq_micro_to_u16(dump+80));
272 	dev_info(micro->dev, "frame rate: %u fps\n",
273 		 ipaq_micro_to_u16(dump+82));
274 	dev_info(micro->dev, "page mode: %u\n", ipaq_micro_to_u16(dump+84));
275 	dev_info(micro->dev, "country ID: %u\n", ipaq_micro_to_u16(dump+86));
276 	dev_info(micro->dev, "color display: %s\n",
277 		 ipaq_micro_to_u16(dump+88) ? "yes" : "no");
278 	dev_info(micro->dev, "ROM size: %u MiB\n", ipaq_micro_to_u16(dump+90));
279 	dev_info(micro->dev, "RAM size: %u KiB\n", ipaq_micro_to_u16(dump+92));
280 	dev_info(micro->dev, "screen: %u x %u\n",
281 		 ipaq_micro_to_u16(dump+94), ipaq_micro_to_u16(dump+96));
282 }
283 
284 static void micro_tx_chars(struct ipaq_micro *micro)
285 {
286 	struct ipaq_micro_txdev *tx = &micro->tx;
287 	u32 val;
288 
289 	while ((tx->index < tx->len) &&
290 	       (readl(micro->base + UTSR1) & UTSR1_TNF)) {
291 		writel(tx->buf[tx->index], micro->base + UTDR);
292 		tx->index++;
293 	}
294 
295 	/* Stop interrupts */
296 	val = readl(micro->base + UTCR3);
297 	val &= ~UTCR3_TIE;
298 	writel(val, micro->base + UTCR3);
299 }
300 
301 static void micro_reset_comm(struct ipaq_micro *micro)
302 {
303 	struct ipaq_micro_rxdev *rx = &micro->rx;
304 	u32 val;
305 
306 	if (micro->msg)
307 		complete(&micro->msg->ack);
308 
309 	/* Initialize Serial channel protocol frame */
310 	rx->state = STATE_SOF;  /* Reset the state machine */
311 
312 	/* Set up interrupts */
313 	writel(0x01, micro->sdlc + 0x0); /* Select UART mode */
314 
315 	/* Clean up CR3 */
316 	writel(0x0, micro->base + UTCR3);
317 
318 	/* Format: 8N1 */
319 	writel(UTCR0_8BitData | UTCR0_1StpBit, micro->base + UTCR0);
320 
321 	/* Baud rate: 115200 */
322 	writel(0x0, micro->base + UTCR1);
323 	writel(0x1, micro->base + UTCR2);
324 
325 	/* Clear SR0 */
326 	writel(0xff, micro->base + UTSR0);
327 
328 	/* Enable RX int, disable TX int */
329 	writel(UTCR3_TXE | UTCR3_RXE | UTCR3_RIE, micro->base + UTCR3);
330 	val = readl(micro->base + UTCR3);
331 	val &= ~UTCR3_TIE;
332 	writel(val, micro->base + UTCR3);
333 }
334 
335 static irqreturn_t micro_serial_isr(int irq, void *dev_id)
336 {
337 	struct ipaq_micro *micro = dev_id;
338 	struct ipaq_micro_txdev *tx = &micro->tx;
339 	u32 status;
340 
341 	status = readl(micro->base + UTSR0);
342 	do {
343 		if (status & (UTSR0_RID | UTSR0_RFS)) {
344 			if (status & UTSR0_RID)
345 				/* Clear the Receiver IDLE bit */
346 				writel(UTSR0_RID, micro->base + UTSR0);
347 			micro_rx_chars(micro);
348 		}
349 
350 		/* Clear break bits */
351 		if (status & (UTSR0_RBB | UTSR0_REB))
352 			writel(status & (UTSR0_RBB | UTSR0_REB),
353 			       micro->base + UTSR0);
354 
355 		if (status & UTSR0_TFS)
356 			micro_tx_chars(micro);
357 
358 		status = readl(micro->base + UTSR0);
359 
360 	} while (((tx->index < tx->len) && (status & UTSR0_TFS)) ||
361 		 (status & (UTSR0_RFS | UTSR0_RID)));
362 
363 	return IRQ_HANDLED;
364 }
365 
366 static const struct mfd_cell micro_cells[] = {
367 	{ .name = "ipaq-micro-backlight", },
368 	{ .name = "ipaq-micro-battery", },
369 	{ .name = "ipaq-micro-keys", },
370 	{ .name = "ipaq-micro-ts", },
371 	{ .name = "ipaq-micro-leds", },
372 };
373 
374 static int __maybe_unused micro_resume(struct device *dev)
375 {
376 	struct ipaq_micro *micro = dev_get_drvdata(dev);
377 
378 	micro_reset_comm(micro);
379 	mdelay(10);
380 
381 	return 0;
382 }
383 
384 static int __init micro_probe(struct platform_device *pdev)
385 {
386 	struct ipaq_micro *micro;
387 	struct resource *res;
388 	int ret;
389 	int irq;
390 
391 	micro = devm_kzalloc(&pdev->dev, sizeof(*micro), GFP_KERNEL);
392 	if (!micro)
393 		return -ENOMEM;
394 
395 	micro->dev = &pdev->dev;
396 
397 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
398 	micro->base = devm_ioremap_resource(&pdev->dev, res);
399 	if (IS_ERR(micro->base))
400 		return PTR_ERR(micro->base);
401 
402 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
403 	if (!res)
404 		return -EINVAL;
405 
406 	micro->sdlc = devm_ioremap_resource(&pdev->dev, res);
407 	if (IS_ERR(micro->sdlc))
408 		return PTR_ERR(micro->sdlc);
409 
410 	micro_reset_comm(micro);
411 
412 	irq = platform_get_irq(pdev, 0);
413 	if (!irq)
414 		return -EINVAL;
415 	ret = devm_request_irq(&pdev->dev, irq, micro_serial_isr,
416 			       IRQF_SHARED, "ipaq-micro",
417 			       micro);
418 	if (ret) {
419 		dev_err(&pdev->dev, "unable to grab serial port IRQ\n");
420 		return ret;
421 	} else
422 		dev_info(&pdev->dev, "grabbed serial port IRQ\n");
423 
424 	spin_lock_init(&micro->lock);
425 	INIT_LIST_HEAD(&micro->queue);
426 	platform_set_drvdata(pdev, micro);
427 
428 	ret = mfd_add_devices(&pdev->dev, pdev->id, micro_cells,
429 			      ARRAY_SIZE(micro_cells), NULL, 0, NULL);
430 	if (ret) {
431 		dev_err(&pdev->dev, "error adding MFD cells");
432 		return ret;
433 	}
434 
435 	/* Check version */
436 	ipaq_micro_get_version(micro);
437 	dev_info(&pdev->dev, "Atmel micro ASIC version %s\n", micro->version);
438 	ipaq_micro_eeprom_dump(micro);
439 
440 	return 0;
441 }
442 
443 static const struct dev_pm_ops micro_dev_pm_ops = {
444 	SET_SYSTEM_SLEEP_PM_OPS(NULL, micro_resume)
445 };
446 
447 static struct platform_driver micro_device_driver = {
448 	.driver   = {
449 		.name	= "ipaq-h3xxx-micro",
450 		.pm	= &micro_dev_pm_ops,
451 		.suppress_bind_attrs = true,
452 	},
453 };
454 builtin_platform_driver_probe(micro_device_driver, micro_probe);
455