xref: /linux/drivers/mfd/ipaq-micro.c (revision 80739fd00c7ea1315d362ce889bef499452913ef)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Compaq iPAQ h3xxx Atmel microcontroller companion support
4  *
5  * This is an Atmel AT90LS8535 with a special flashed-in firmware that
6  * implements the special protocol used by this driver.
7  *
8  * based on previous kernel 2.4 version by Andrew Christian
9  * Author : Alessandro Gardich <gremlin@gremlin.it>
10  * Author : Dmitry Artamonow <mad_soft@inbox.ru>
11  * Author : Linus Walleij <linus.walleij@linaro.org>
12  */
13 
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/interrupt.h>
17 #include <linux/pm.h>
18 #include <linux/delay.h>
19 #include <linux/device.h>
20 #include <linux/platform_device.h>
21 #include <linux/io.h>
22 #include <linux/mfd/core.h>
23 #include <linux/mfd/ipaq-micro.h>
24 #include <linux/string.h>
25 #include <linux/random.h>
26 #include <linux/slab.h>
27 #include <linux/list.h>
28 
29 #include <mach/hardware.h>
30 
ipaq_micro_trigger_tx(struct ipaq_micro * micro)31 static void ipaq_micro_trigger_tx(struct ipaq_micro *micro)
32 {
33 	struct ipaq_micro_txdev *tx = &micro->tx;
34 	struct ipaq_micro_msg *msg = micro->msg;
35 	int i, bp;
36 	u8 checksum;
37 	u32 val;
38 
39 	bp = 0;
40 	tx->buf[bp++] = CHAR_SOF;
41 
42 	checksum = ((msg->id & 0x0f) << 4) | (msg->tx_len & 0x0f);
43 	tx->buf[bp++] = checksum;
44 
45 	for (i = 0; i < msg->tx_len; i++) {
46 		tx->buf[bp++] = msg->tx_data[i];
47 		checksum += msg->tx_data[i];
48 	}
49 
50 	tx->buf[bp++] = checksum;
51 	tx->len = bp;
52 	tx->index = 0;
53 
54 	/* Enable interrupt */
55 	val = readl(micro->base + UTCR3);
56 	val |= UTCR3_TIE;
57 	writel(val, micro->base + UTCR3);
58 }
59 
ipaq_micro_tx_msg(struct ipaq_micro * micro,struct ipaq_micro_msg * msg)60 int ipaq_micro_tx_msg(struct ipaq_micro *micro, struct ipaq_micro_msg *msg)
61 {
62 	unsigned long flags;
63 
64 	dev_dbg(micro->dev, "TX msg: %02x, %d bytes\n", msg->id, msg->tx_len);
65 
66 	spin_lock_irqsave(&micro->lock, flags);
67 	if (micro->msg) {
68 		list_add_tail(&msg->node, &micro->queue);
69 		spin_unlock_irqrestore(&micro->lock, flags);
70 		return 0;
71 	}
72 	micro->msg = msg;
73 	ipaq_micro_trigger_tx(micro);
74 	spin_unlock_irqrestore(&micro->lock, flags);
75 	return 0;
76 }
77 EXPORT_SYMBOL(ipaq_micro_tx_msg);
78 
micro_rx_msg(struct ipaq_micro * micro,u8 id,int len,u8 * data)79 static void micro_rx_msg(struct ipaq_micro *micro, u8 id, int len, u8 *data)
80 {
81 	dev_dbg(micro->dev, "RX msg: %02x, %d bytes\n", id, len);
82 
83 	spin_lock(&micro->lock);
84 	switch (id) {
85 	case MSG_VERSION:
86 	case MSG_EEPROM_READ:
87 	case MSG_EEPROM_WRITE:
88 	case MSG_BACKLIGHT:
89 	case MSG_NOTIFY_LED:
90 	case MSG_THERMAL_SENSOR:
91 	case MSG_BATTERY:
92 		/* Handle synchronous messages */
93 		if (micro->msg && micro->msg->id == id) {
94 			struct ipaq_micro_msg *msg = micro->msg;
95 
96 			memcpy(msg->rx_data, data, len);
97 			msg->rx_len = len;
98 			complete(&micro->msg->ack);
99 			if (!list_empty(&micro->queue)) {
100 				micro->msg = list_entry(micro->queue.next,
101 							struct ipaq_micro_msg,
102 							node);
103 				list_del_init(&micro->msg->node);
104 				ipaq_micro_trigger_tx(micro);
105 			} else
106 				micro->msg = NULL;
107 			dev_dbg(micro->dev, "OK RX message 0x%02x\n", id);
108 		} else {
109 			dev_err(micro->dev,
110 				"out of band RX message 0x%02x\n", id);
111 			if (!micro->msg)
112 				dev_info(micro->dev, "no message queued\n");
113 			else
114 				dev_info(micro->dev, "expected message %02x\n",
115 					 micro->msg->id);
116 		}
117 		break;
118 	case MSG_KEYBOARD:
119 		if (micro->key)
120 			micro->key(micro->key_data, len, data);
121 		else
122 			dev_dbg(micro->dev, "key message ignored, no handle\n");
123 		break;
124 	case MSG_TOUCHSCREEN:
125 		if (micro->ts)
126 			micro->ts(micro->ts_data, len, data);
127 		else
128 			dev_dbg(micro->dev, "touchscreen message ignored, no handle\n");
129 		break;
130 	default:
131 		dev_err(micro->dev,
132 			"unknown msg %d [%d] %*ph\n", id, len, len, data);
133 		break;
134 	}
135 	spin_unlock(&micro->lock);
136 }
137 
micro_process_char(struct ipaq_micro * micro,u8 ch)138 static void micro_process_char(struct ipaq_micro *micro, u8 ch)
139 {
140 	struct ipaq_micro_rxdev *rx = &micro->rx;
141 
142 	switch (rx->state) {
143 	case STATE_SOF:	/* Looking for SOF */
144 		if (ch == CHAR_SOF)
145 			rx->state = STATE_ID; /* Next byte is the id and len */
146 		break;
147 	case STATE_ID: /* Looking for id and len byte */
148 		rx->id = (ch & 0xf0) >> 4;
149 		rx->len = (ch & 0x0f);
150 		rx->index = 0;
151 		rx->chksum = ch;
152 		rx->state = (rx->len > 0) ? STATE_DATA : STATE_CHKSUM;
153 		break;
154 	case STATE_DATA: /* Looking for 'len' data bytes */
155 		rx->chksum += ch;
156 		rx->buf[rx->index] = ch;
157 		if (++rx->index == rx->len)
158 			rx->state = STATE_CHKSUM;
159 		break;
160 	case STATE_CHKSUM: /* Looking for the checksum */
161 		if (ch == rx->chksum)
162 			micro_rx_msg(micro, rx->id, rx->len, rx->buf);
163 		rx->state = STATE_SOF;
164 		break;
165 	}
166 }
167 
micro_rx_chars(struct ipaq_micro * micro)168 static void micro_rx_chars(struct ipaq_micro *micro)
169 {
170 	u32 status, ch;
171 
172 	while ((status = readl(micro->base + UTSR1)) & UTSR1_RNE) {
173 		ch = readl(micro->base + UTDR);
174 		if (status & UTSR1_PRE)
175 			dev_err(micro->dev, "rx: parity error\n");
176 		else if (status & UTSR1_FRE)
177 			dev_err(micro->dev, "rx: framing error\n");
178 		else if (status & UTSR1_ROR)
179 			dev_err(micro->dev, "rx: overrun error\n");
180 		micro_process_char(micro, ch);
181 	}
182 }
183 
ipaq_micro_get_version(struct ipaq_micro * micro)184 static void ipaq_micro_get_version(struct ipaq_micro *micro)
185 {
186 	struct ipaq_micro_msg msg = {
187 		.id = MSG_VERSION,
188 	};
189 
190 	ipaq_micro_tx_msg_sync(micro, &msg);
191 	if (msg.rx_len == 4) {
192 		memcpy(micro->version, msg.rx_data, 4);
193 		micro->version[4] = '\0';
194 	} else if (msg.rx_len == 9) {
195 		memcpy(micro->version, msg.rx_data, 4);
196 		micro->version[4] = '\0';
197 		/* Bytes 4-7 are "pack", byte 8 is "boot type" */
198 	} else {
199 		dev_err(micro->dev,
200 			"illegal version message %d bytes\n", msg.rx_len);
201 	}
202 }
203 
ipaq_micro_eeprom_read(struct ipaq_micro * micro,u8 address,u8 len,u8 * data)204 static void ipaq_micro_eeprom_read(struct ipaq_micro *micro,
205 				   u8 address, u8 len, u8 *data)
206 {
207 	struct ipaq_micro_msg msg = {
208 		.id = MSG_EEPROM_READ,
209 	};
210 	u8 i;
211 
212 	for (i = 0; i < len; i++) {
213 		msg.tx_data[0] = address + i;
214 		msg.tx_data[1] = 1;
215 		msg.tx_len = 2;
216 		ipaq_micro_tx_msg_sync(micro, &msg);
217 		memcpy(data + (i * 2), msg.rx_data, 2);
218 	}
219 }
220 
ipaq_micro_str(u8 * wchar,u8 len)221 static char *ipaq_micro_str(u8 *wchar, u8 len)
222 {
223 	char retstr[256];
224 	u8 i;
225 
226 	for (i = 0; i < len / 2; i++)
227 		retstr[i] = wchar[i * 2];
228 	return kstrdup(retstr, GFP_KERNEL);
229 }
230 
ipaq_micro_to_u16(u8 * data)231 static u16 ipaq_micro_to_u16(u8 *data)
232 {
233 	return data[1] << 8 | data[0];
234 }
235 
ipaq_micro_eeprom_dump(struct ipaq_micro * micro)236 static void __init ipaq_micro_eeprom_dump(struct ipaq_micro *micro)
237 {
238 	u8 dump[256];
239 	char *str;
240 
241 	ipaq_micro_eeprom_read(micro, 0, 128, dump);
242 	str = ipaq_micro_str(dump, 10);
243 	if (str) {
244 		dev_info(micro->dev, "HW version %s\n", str);
245 		kfree(str);
246 	}
247 	str = ipaq_micro_str(dump+10, 40);
248 	if (str) {
249 		dev_info(micro->dev, "serial number: %s\n", str);
250 		/* Feed the random pool with this */
251 		add_device_randomness(str, strlen(str));
252 		kfree(str);
253 	}
254 	str = ipaq_micro_str(dump+50, 20);
255 	if (str) {
256 		dev_info(micro->dev, "module ID: %s\n", str);
257 		kfree(str);
258 	}
259 	str = ipaq_micro_str(dump+70, 10);
260 	if (str) {
261 		dev_info(micro->dev, "product revision: %s\n", str);
262 		kfree(str);
263 	}
264 	dev_info(micro->dev, "product ID: %u\n", ipaq_micro_to_u16(dump+80));
265 	dev_info(micro->dev, "frame rate: %u fps\n",
266 		 ipaq_micro_to_u16(dump+82));
267 	dev_info(micro->dev, "page mode: %u\n", ipaq_micro_to_u16(dump+84));
268 	dev_info(micro->dev, "country ID: %u\n", ipaq_micro_to_u16(dump+86));
269 	dev_info(micro->dev, "color display: %s\n",
270 		 ipaq_micro_to_u16(dump+88) ? "yes" : "no");
271 	dev_info(micro->dev, "ROM size: %u MiB\n", ipaq_micro_to_u16(dump+90));
272 	dev_info(micro->dev, "RAM size: %u KiB\n", ipaq_micro_to_u16(dump+92));
273 	dev_info(micro->dev, "screen: %u x %u\n",
274 		 ipaq_micro_to_u16(dump+94), ipaq_micro_to_u16(dump+96));
275 }
276 
micro_tx_chars(struct ipaq_micro * micro)277 static void micro_tx_chars(struct ipaq_micro *micro)
278 {
279 	struct ipaq_micro_txdev *tx = &micro->tx;
280 	u32 val;
281 
282 	while ((tx->index < tx->len) &&
283 	       (readl(micro->base + UTSR1) & UTSR1_TNF)) {
284 		writel(tx->buf[tx->index], micro->base + UTDR);
285 		tx->index++;
286 	}
287 
288 	/* Stop interrupts */
289 	val = readl(micro->base + UTCR3);
290 	val &= ~UTCR3_TIE;
291 	writel(val, micro->base + UTCR3);
292 }
293 
micro_reset_comm(struct ipaq_micro * micro)294 static void micro_reset_comm(struct ipaq_micro *micro)
295 {
296 	struct ipaq_micro_rxdev *rx = &micro->rx;
297 	u32 val;
298 
299 	if (micro->msg)
300 		complete(&micro->msg->ack);
301 
302 	/* Initialize Serial channel protocol frame */
303 	rx->state = STATE_SOF;  /* Reset the state machine */
304 
305 	/* Set up interrupts */
306 	writel(0x01, micro->sdlc + 0x0); /* Select UART mode */
307 
308 	/* Clean up CR3 */
309 	writel(0x0, micro->base + UTCR3);
310 
311 	/* Format: 8N1 */
312 	writel(UTCR0_8BitData | UTCR0_1StpBit, micro->base + UTCR0);
313 
314 	/* Baud rate: 115200 */
315 	writel(0x0, micro->base + UTCR1);
316 	writel(0x1, micro->base + UTCR2);
317 
318 	/* Clear SR0 */
319 	writel(0xff, micro->base + UTSR0);
320 
321 	/* Enable RX int, disable TX int */
322 	writel(UTCR3_TXE | UTCR3_RXE | UTCR3_RIE, micro->base + UTCR3);
323 	val = readl(micro->base + UTCR3);
324 	val &= ~UTCR3_TIE;
325 	writel(val, micro->base + UTCR3);
326 }
327 
micro_serial_isr(int irq,void * dev_id)328 static irqreturn_t micro_serial_isr(int irq, void *dev_id)
329 {
330 	struct ipaq_micro *micro = dev_id;
331 	struct ipaq_micro_txdev *tx = &micro->tx;
332 	u32 status;
333 
334 	status = readl(micro->base + UTSR0);
335 	do {
336 		if (status & (UTSR0_RID | UTSR0_RFS)) {
337 			if (status & UTSR0_RID)
338 				/* Clear the Receiver IDLE bit */
339 				writel(UTSR0_RID, micro->base + UTSR0);
340 			micro_rx_chars(micro);
341 		}
342 
343 		/* Clear break bits */
344 		if (status & (UTSR0_RBB | UTSR0_REB))
345 			writel(status & (UTSR0_RBB | UTSR0_REB),
346 			       micro->base + UTSR0);
347 
348 		if (status & UTSR0_TFS)
349 			micro_tx_chars(micro);
350 
351 		status = readl(micro->base + UTSR0);
352 
353 	} while (((tx->index < tx->len) && (status & UTSR0_TFS)) ||
354 		 (status & (UTSR0_RFS | UTSR0_RID)));
355 
356 	return IRQ_HANDLED;
357 }
358 
359 static const struct mfd_cell micro_cells[] = {
360 	{ .name = "ipaq-micro-backlight", },
361 	{ .name = "ipaq-micro-battery", },
362 	{ .name = "ipaq-micro-keys", },
363 	{ .name = "ipaq-micro-ts", },
364 	{ .name = "ipaq-micro-leds", },
365 };
366 
micro_resume(struct device * dev)367 static int __maybe_unused micro_resume(struct device *dev)
368 {
369 	struct ipaq_micro *micro = dev_get_drvdata(dev);
370 
371 	micro_reset_comm(micro);
372 	mdelay(10);
373 
374 	return 0;
375 }
376 
micro_probe(struct platform_device * pdev)377 static int __init micro_probe(struct platform_device *pdev)
378 {
379 	struct ipaq_micro *micro;
380 	int ret;
381 	int irq;
382 
383 	micro = devm_kzalloc(&pdev->dev, sizeof(*micro), GFP_KERNEL);
384 	if (!micro)
385 		return -ENOMEM;
386 
387 	micro->dev = &pdev->dev;
388 
389 	micro->base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
390 	if (IS_ERR(micro->base))
391 		return PTR_ERR(micro->base);
392 
393 	micro->sdlc = devm_platform_ioremap_resource(pdev, 1);
394 	if (IS_ERR(micro->sdlc))
395 		return PTR_ERR(micro->sdlc);
396 
397 	micro_reset_comm(micro);
398 
399 	irq = platform_get_irq(pdev, 0);
400 	if (irq < 0)
401 		return -EINVAL;
402 	ret = devm_request_irq(&pdev->dev, irq, micro_serial_isr,
403 			       IRQF_SHARED, "ipaq-micro",
404 			       micro);
405 	if (ret) {
406 		dev_err(&pdev->dev, "unable to grab serial port IRQ\n");
407 		return ret;
408 	} else
409 		dev_info(&pdev->dev, "grabbed serial port IRQ\n");
410 
411 	spin_lock_init(&micro->lock);
412 	INIT_LIST_HEAD(&micro->queue);
413 	platform_set_drvdata(pdev, micro);
414 
415 	ret = mfd_add_devices(&pdev->dev, pdev->id, micro_cells,
416 			      ARRAY_SIZE(micro_cells), NULL, 0, NULL);
417 	if (ret) {
418 		dev_err(&pdev->dev, "error adding MFD cells");
419 		return ret;
420 	}
421 
422 	/* Check version */
423 	ipaq_micro_get_version(micro);
424 	dev_info(&pdev->dev, "Atmel micro ASIC version %s\n", micro->version);
425 	ipaq_micro_eeprom_dump(micro);
426 
427 	return 0;
428 }
429 
430 static const struct dev_pm_ops micro_dev_pm_ops = {
431 	SET_SYSTEM_SLEEP_PM_OPS(NULL, micro_resume)
432 };
433 
434 static struct platform_driver micro_device_driver = {
435 	.driver   = {
436 		.name	= "ipaq-h3xxx-micro",
437 		.pm	= &micro_dev_pm_ops,
438 		.suppress_bind_attrs = true,
439 	},
440 };
441 builtin_platform_driver_probe(micro_device_driver, micro_probe);
442