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
34static 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(KERN_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
65int 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}
82EXPORT_SYMBOL(ipaq_micro_tx_msg);
83
84static 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
147static 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
177static 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
193static 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
213static 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
230static 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
240static u16 ipaq_micro_to_u16(u8 *data)
241{
242	return data[1] << 8 | data[0];
243}
244
245static void 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, "HM 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(KERN_DEBUG, "eeprom: ", DUMP_PREFIX_OFFSET, 16, 1,
285		       dump, 256, true);
286
287}
288
289static 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
306static 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
340static 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
371static 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
379static int 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
389static int 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
451static int micro_remove(struct platform_device *pdev)
452{
453	struct ipaq_micro *micro = platform_get_drvdata(pdev);
454	u32 val;
455
456	mfd_remove_devices(&pdev->dev);
457
458	val = readl(micro->base + UTCR3);
459	val &= ~(UTCR3_RXE | UTCR3_RIE); /* disable receive interrupt */
460	val &= ~(UTCR3_TXE | UTCR3_TIE); /* disable transmit interrupt */
461	writel(val, micro->base + UTCR3);
462
463	return 0;
464}
465
466static const struct dev_pm_ops micro_dev_pm_ops = {
467	SET_SYSTEM_SLEEP_PM_OPS(NULL, micro_resume)
468};
469
470static struct platform_driver micro_device_driver = {
471	.driver   = {
472		.name	= "ipaq-h3xxx-micro",
473		.pm	= &micro_dev_pm_ops,
474	},
475	.probe    = micro_probe,
476	.remove   = micro_remove,
477	/* .shutdown = micro_suspend, // FIXME */
478};
479module_platform_driver(micro_device_driver);
480
481MODULE_LICENSE("GPL");
482MODULE_DESCRIPTION("driver for iPAQ Atmel micro core and backlight");
483