2 * drivers/w1/masters/omap_hdq.c
4 * Copyright (C) 2007,2012 Texas Instruments, Inc.
6 * This file is licensed under the terms of the GNU General Public License
7 * version 2. This program is licensed "as is" without any warranty of any
8 * kind, whether express or implied.
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/interrupt.h>
15 #include <linux/slab.h>
16 #include <linux/err.h>
18 #include <linux/sched.h>
19 #include <linux/pm_runtime.h>
22 #include "../w1_int.h"
24 #define MOD_NAME "OMAP_HDQ:"
26 #define OMAP_HDQ_REVISION 0x00
27 #define OMAP_HDQ_TX_DATA 0x04
28 #define OMAP_HDQ_RX_DATA 0x08
29 #define OMAP_HDQ_CTRL_STATUS 0x0c
30 #define OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK (1<<6)
31 #define OMAP_HDQ_CTRL_STATUS_CLOCKENABLE (1<<5)
32 #define OMAP_HDQ_CTRL_STATUS_GO (1<<4)
33 #define OMAP_HDQ_CTRL_STATUS_INITIALIZATION (1<<2)
34 #define OMAP_HDQ_CTRL_STATUS_DIR (1<<1)
35 #define OMAP_HDQ_CTRL_STATUS_MODE (1<<0)
36 #define OMAP_HDQ_INT_STATUS 0x10
37 #define OMAP_HDQ_INT_STATUS_TXCOMPLETE (1<<2)
38 #define OMAP_HDQ_INT_STATUS_RXCOMPLETE (1<<1)
39 #define OMAP_HDQ_INT_STATUS_TIMEOUT (1<<0)
40 #define OMAP_HDQ_SYSCONFIG 0x14
41 #define OMAP_HDQ_SYSCONFIG_SOFTRESET (1<<1)
42 #define OMAP_HDQ_SYSCONFIG_AUTOIDLE (1<<0)
43 #define OMAP_HDQ_SYSSTATUS 0x18
44 #define OMAP_HDQ_SYSSTATUS_RESETDONE (1<<0)
46 #define OMAP_HDQ_FLAG_CLEAR 0
47 #define OMAP_HDQ_FLAG_SET 1
48 #define OMAP_HDQ_TIMEOUT (HZ/5)
50 #define OMAP_HDQ_MAX_USER 4
52 static DECLARE_WAIT_QUEUE_HEAD(hdq_wait_queue);
57 void __iomem *hdq_base;
58 /* lock status update */
59 struct mutex hdq_mutex;
63 spinlock_t hdq_spinlock;
65 * Used to control the call to omap_hdq_get and omap_hdq_put.
66 * HDQ Protocol: Write the CMD|REG_address first, followed by
67 * the data wrire or read.
72 static int omap_hdq_probe(struct platform_device *pdev);
73 static int omap_hdq_remove(struct platform_device *pdev);
75 static struct of_device_id omap_hdq_dt_ids[] = {
76 { .compatible = "ti,omap3-1w" },
79 MODULE_DEVICE_TABLE(of, omap_hdq_dt_ids);
81 static struct platform_driver omap_hdq_driver = {
82 .probe = omap_hdq_probe,
83 .remove = omap_hdq_remove,
86 .of_match_table = omap_hdq_dt_ids,
90 static u8 omap_w1_read_byte(void *_hdq);
91 static void omap_w1_write_byte(void *_hdq, u8 byte);
92 static u8 omap_w1_reset_bus(void *_hdq);
93 static void omap_w1_search_bus(void *_hdq, struct w1_master *master_dev,
94 u8 search_type, w1_slave_found_callback slave_found);
97 static struct w1_bus_master omap_w1_master = {
98 .read_byte = omap_w1_read_byte,
99 .write_byte = omap_w1_write_byte,
100 .reset_bus = omap_w1_reset_bus,
101 .search = omap_w1_search_bus,
104 /* HDQ register I/O routines */
105 static inline u8 hdq_reg_in(struct hdq_data *hdq_data, u32 offset)
107 return __raw_readl(hdq_data->hdq_base + offset);
110 static inline void hdq_reg_out(struct hdq_data *hdq_data, u32 offset, u8 val)
112 __raw_writel(val, hdq_data->hdq_base + offset);
115 static inline u8 hdq_reg_merge(struct hdq_data *hdq_data, u32 offset,
118 u8 new_val = (__raw_readl(hdq_data->hdq_base + offset) & ~mask)
120 __raw_writel(new_val, hdq_data->hdq_base + offset);
126 * Wait for one or more bits in flag change.
127 * HDQ_FLAG_SET: wait until any bit in the flag is set.
128 * HDQ_FLAG_CLEAR: wait until all bits in the flag are cleared.
129 * return 0 on success and -ETIMEDOUT in the case of timeout.
131 static int hdq_wait_for_flag(struct hdq_data *hdq_data, u32 offset,
132 u8 flag, u8 flag_set, u8 *status)
135 unsigned long timeout = jiffies + OMAP_HDQ_TIMEOUT;
137 if (flag_set == OMAP_HDQ_FLAG_CLEAR) {
138 /* wait for the flag clear */
139 while (((*status = hdq_reg_in(hdq_data, offset)) & flag)
140 && time_before(jiffies, timeout)) {
141 schedule_timeout_uninterruptible(1);
145 } else if (flag_set == OMAP_HDQ_FLAG_SET) {
146 /* wait for the flag set */
147 while (!((*status = hdq_reg_in(hdq_data, offset)) & flag)
148 && time_before(jiffies, timeout)) {
149 schedule_timeout_uninterruptible(1);
151 if (!(*status & flag))
159 /* write out a byte and fill *status with HDQ_INT_STATUS */
160 static int hdq_write_byte(struct hdq_data *hdq_data, u8 val, u8 *status)
164 unsigned long irqflags;
168 spin_lock_irqsave(&hdq_data->hdq_spinlock, irqflags);
169 /* clear interrupt flags via a dummy read */
170 hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS);
171 /* ISR loads it with new INT_STATUS */
172 hdq_data->hdq_irqstatus = 0;
173 spin_unlock_irqrestore(&hdq_data->hdq_spinlock, irqflags);
175 hdq_reg_out(hdq_data, OMAP_HDQ_TX_DATA, val);
178 hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS, OMAP_HDQ_CTRL_STATUS_GO,
179 OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO);
180 /* wait for the TXCOMPLETE bit */
181 ret = wait_event_timeout(hdq_wait_queue,
182 hdq_data->hdq_irqstatus, OMAP_HDQ_TIMEOUT);
184 dev_dbg(hdq_data->dev, "TX wait elapsed\n");
189 *status = hdq_data->hdq_irqstatus;
190 /* check irqstatus */
191 if (!(*status & OMAP_HDQ_INT_STATUS_TXCOMPLETE)) {
192 dev_dbg(hdq_data->dev, "timeout waiting for"
193 " TXCOMPLETE/RXCOMPLETE, %x", *status);
198 /* wait for the GO bit return to zero */
199 ret = hdq_wait_for_flag(hdq_data, OMAP_HDQ_CTRL_STATUS,
200 OMAP_HDQ_CTRL_STATUS_GO,
201 OMAP_HDQ_FLAG_CLEAR, &tmp_status);
203 dev_dbg(hdq_data->dev, "timeout waiting GO bit"
204 " return to zero, %x", tmp_status);
211 /* HDQ Interrupt service routine */
212 static irqreturn_t hdq_isr(int irq, void *_hdq)
214 struct hdq_data *hdq_data = _hdq;
215 unsigned long irqflags;
217 spin_lock_irqsave(&hdq_data->hdq_spinlock, irqflags);
218 hdq_data->hdq_irqstatus = hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS);
219 spin_unlock_irqrestore(&hdq_data->hdq_spinlock, irqflags);
220 dev_dbg(hdq_data->dev, "hdq_isr: %x", hdq_data->hdq_irqstatus);
222 if (hdq_data->hdq_irqstatus &
223 (OMAP_HDQ_INT_STATUS_TXCOMPLETE | OMAP_HDQ_INT_STATUS_RXCOMPLETE
224 | OMAP_HDQ_INT_STATUS_TIMEOUT)) {
225 /* wake up sleeping process */
226 wake_up(&hdq_wait_queue);
232 /* HDQ Mode: always return success */
233 static u8 omap_w1_reset_bus(void *_hdq)
238 /* W1 search callback function */
239 static void omap_w1_search_bus(void *_hdq, struct w1_master *master_dev,
240 u8 search_type, w1_slave_found_callback slave_found)
242 u64 module_id, rn_le, cs, id;
249 rn_le = cpu_to_le64(module_id);
251 * HDQ might not obey truly the 1-wire spec.
252 * So calculate CRC based on module parameter.
254 cs = w1_calc_crc8((u8 *)&rn_le, 7);
255 id = (cs << 56) | module_id;
257 slave_found(master_dev, id);
260 static int _omap_hdq_reset(struct hdq_data *hdq_data)
265 hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG, OMAP_HDQ_SYSCONFIG_SOFTRESET);
267 * Select HDQ mode & enable clocks.
268 * It is observed that INT flags can't be cleared via a read and GO/INIT
269 * won't return to zero if interrupt is disabled. So we always enable
272 hdq_reg_out(hdq_data, OMAP_HDQ_CTRL_STATUS,
273 OMAP_HDQ_CTRL_STATUS_CLOCKENABLE |
274 OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK);
276 /* wait for reset to complete */
277 ret = hdq_wait_for_flag(hdq_data, OMAP_HDQ_SYSSTATUS,
278 OMAP_HDQ_SYSSTATUS_RESETDONE, OMAP_HDQ_FLAG_SET, &tmp_status);
280 dev_dbg(hdq_data->dev, "timeout waiting HDQ reset, %x",
283 hdq_reg_out(hdq_data, OMAP_HDQ_CTRL_STATUS,
284 OMAP_HDQ_CTRL_STATUS_CLOCKENABLE |
285 OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK);
286 hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG,
287 OMAP_HDQ_SYSCONFIG_AUTOIDLE);
293 /* Issue break pulse to the device */
294 static int omap_hdq_break(struct hdq_data *hdq_data)
298 unsigned long irqflags;
300 ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
302 dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
307 spin_lock_irqsave(&hdq_data->hdq_spinlock, irqflags);
308 /* clear interrupt flags via a dummy read */
309 hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS);
310 /* ISR loads it with new INT_STATUS */
311 hdq_data->hdq_irqstatus = 0;
312 spin_unlock_irqrestore(&hdq_data->hdq_spinlock, irqflags);
314 /* set the INIT and GO bit */
315 hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS,
316 OMAP_HDQ_CTRL_STATUS_INITIALIZATION | OMAP_HDQ_CTRL_STATUS_GO,
317 OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_INITIALIZATION |
318 OMAP_HDQ_CTRL_STATUS_GO);
320 /* wait for the TIMEOUT bit */
321 ret = wait_event_timeout(hdq_wait_queue,
322 hdq_data->hdq_irqstatus, OMAP_HDQ_TIMEOUT);
324 dev_dbg(hdq_data->dev, "break wait elapsed\n");
329 tmp_status = hdq_data->hdq_irqstatus;
330 /* check irqstatus */
331 if (!(tmp_status & OMAP_HDQ_INT_STATUS_TIMEOUT)) {
332 dev_dbg(hdq_data->dev, "timeout waiting for TIMEOUT, %x",
338 * wait for both INIT and GO bits rerurn to zero.
339 * zero wait time expected for interrupt mode.
341 ret = hdq_wait_for_flag(hdq_data, OMAP_HDQ_CTRL_STATUS,
342 OMAP_HDQ_CTRL_STATUS_INITIALIZATION |
343 OMAP_HDQ_CTRL_STATUS_GO, OMAP_HDQ_FLAG_CLEAR,
346 dev_dbg(hdq_data->dev, "timeout waiting INIT&GO bits"
347 " return to zero, %x", tmp_status);
350 mutex_unlock(&hdq_data->hdq_mutex);
355 static int hdq_read_byte(struct hdq_data *hdq_data, u8 *val)
360 ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
366 if (!hdq_data->hdq_usecount) {
371 if (!(hdq_data->hdq_irqstatus & OMAP_HDQ_INT_STATUS_RXCOMPLETE)) {
372 hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS,
373 OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO,
374 OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO);
376 * The RX comes immediately after TX.
378 wait_event_timeout(hdq_wait_queue,
379 (hdq_data->hdq_irqstatus
380 & OMAP_HDQ_INT_STATUS_RXCOMPLETE),
383 hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS, 0,
384 OMAP_HDQ_CTRL_STATUS_DIR);
385 status = hdq_data->hdq_irqstatus;
386 /* check irqstatus */
387 if (!(status & OMAP_HDQ_INT_STATUS_RXCOMPLETE)) {
388 dev_dbg(hdq_data->dev, "timeout waiting for"
389 " RXCOMPLETE, %x", status);
394 /* the data is ready. Read it in! */
395 *val = hdq_reg_in(hdq_data, OMAP_HDQ_RX_DATA);
397 mutex_unlock(&hdq_data->hdq_mutex);
403 /* Enable clocks and set the controller to HDQ mode */
404 static int omap_hdq_get(struct hdq_data *hdq_data)
408 ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
414 if (OMAP_HDQ_MAX_USER == hdq_data->hdq_usecount) {
415 dev_dbg(hdq_data->dev, "attempt to exceed the max use count");
419 hdq_data->hdq_usecount++;
420 try_module_get(THIS_MODULE);
421 if (1 == hdq_data->hdq_usecount) {
423 pm_runtime_get_sync(hdq_data->dev);
425 /* make sure HDQ is out of reset */
426 if (!(hdq_reg_in(hdq_data, OMAP_HDQ_SYSSTATUS) &
427 OMAP_HDQ_SYSSTATUS_RESETDONE)) {
428 ret = _omap_hdq_reset(hdq_data);
430 /* back up the count */
431 hdq_data->hdq_usecount--;
433 /* select HDQ mode & enable clocks */
434 hdq_reg_out(hdq_data, OMAP_HDQ_CTRL_STATUS,
435 OMAP_HDQ_CTRL_STATUS_CLOCKENABLE |
436 OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK);
437 hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG,
438 OMAP_HDQ_SYSCONFIG_AUTOIDLE);
439 hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS);
445 mutex_unlock(&hdq_data->hdq_mutex);
450 /* Disable clocks to the module */
451 static int omap_hdq_put(struct hdq_data *hdq_data)
455 ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
459 if (0 == hdq_data->hdq_usecount) {
460 dev_dbg(hdq_data->dev, "attempt to decrement use count"
464 hdq_data->hdq_usecount--;
465 module_put(THIS_MODULE);
466 if (0 == hdq_data->hdq_usecount)
467 pm_runtime_put_sync(hdq_data->dev);
469 mutex_unlock(&hdq_data->hdq_mutex);
474 /* Read a byte of data from the device */
475 static u8 omap_w1_read_byte(void *_hdq)
477 struct hdq_data *hdq_data = _hdq;
481 ret = hdq_read_byte(hdq_data, &val);
483 ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
485 dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
488 hdq_data->init_trans = 0;
489 mutex_unlock(&hdq_data->hdq_mutex);
490 omap_hdq_put(hdq_data);
494 /* Write followed by a read, release the module */
495 if (hdq_data->init_trans) {
496 ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
498 dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
501 hdq_data->init_trans = 0;
502 mutex_unlock(&hdq_data->hdq_mutex);
503 omap_hdq_put(hdq_data);
509 /* Write a byte of data to the device */
510 static void omap_w1_write_byte(void *_hdq, u8 byte)
512 struct hdq_data *hdq_data = _hdq;
516 /* First write to initialize the transfer */
517 if (hdq_data->init_trans == 0)
518 omap_hdq_get(hdq_data);
520 ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
522 dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
525 hdq_data->init_trans++;
526 mutex_unlock(&hdq_data->hdq_mutex);
528 ret = hdq_write_byte(hdq_data, byte, &status);
530 dev_dbg(hdq_data->dev, "TX failure:Ctrl status %x\n", status);
534 /* Second write, data transferred. Release the module */
535 if (hdq_data->init_trans > 1) {
536 omap_hdq_put(hdq_data);
537 ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
539 dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
542 hdq_data->init_trans = 0;
543 mutex_unlock(&hdq_data->hdq_mutex);
547 static int omap_hdq_probe(struct platform_device *pdev)
549 struct device *dev = &pdev->dev;
550 struct hdq_data *hdq_data;
551 struct resource *res;
555 hdq_data = devm_kzalloc(dev, sizeof(*hdq_data), GFP_KERNEL);
557 dev_dbg(&pdev->dev, "unable to allocate memory\n");
562 platform_set_drvdata(pdev, hdq_data);
564 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
565 hdq_data->hdq_base = devm_ioremap_resource(dev, res);
566 if (IS_ERR(hdq_data->hdq_base))
567 return PTR_ERR(hdq_data->hdq_base);
569 hdq_data->hdq_usecount = 0;
570 mutex_init(&hdq_data->hdq_mutex);
572 pm_runtime_enable(&pdev->dev);
573 pm_runtime_get_sync(&pdev->dev);
575 rev = hdq_reg_in(hdq_data, OMAP_HDQ_REVISION);
576 dev_info(&pdev->dev, "OMAP HDQ Hardware Rev %c.%c. Driver in %s mode\n",
577 (rev >> 4) + '0', (rev & 0x0f) + '0', "Interrupt");
579 spin_lock_init(&hdq_data->hdq_spinlock);
581 irq = platform_get_irq(pdev, 0);
587 ret = devm_request_irq(dev, irq, hdq_isr, 0, "omap_hdq", hdq_data);
589 dev_dbg(&pdev->dev, "could not request irq\n");
593 omap_hdq_break(hdq_data);
595 pm_runtime_put_sync(&pdev->dev);
597 omap_w1_master.data = hdq_data;
599 ret = w1_add_master_device(&omap_w1_master);
601 dev_dbg(&pdev->dev, "Failure in registering w1 master\n");
608 pm_runtime_put_sync(&pdev->dev);
610 pm_runtime_disable(&pdev->dev);
615 static int omap_hdq_remove(struct platform_device *pdev)
617 struct hdq_data *hdq_data = platform_get_drvdata(pdev);
619 mutex_lock(&hdq_data->hdq_mutex);
621 if (hdq_data->hdq_usecount) {
622 dev_dbg(&pdev->dev, "removed when use count is not zero\n");
623 mutex_unlock(&hdq_data->hdq_mutex);
627 mutex_unlock(&hdq_data->hdq_mutex);
629 /* remove module dependency */
630 pm_runtime_disable(&pdev->dev);
635 module_platform_driver(omap_hdq_driver);
637 module_param(w1_id, int, S_IRUSR);
638 MODULE_PARM_DESC(w1_id, "1-wire id for the slave detection");
640 MODULE_AUTHOR("Texas Instruments");
641 MODULE_DESCRIPTION("HDQ driver Library");
642 MODULE_LICENSE("GPL");