ipaq-micro.c

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