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