1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2007,2012 Texas Instruments, Inc.
5 #include <linux/kernel.h>
6 #include <linux/module.h>
7 #include <linux/platform_device.h>
8 #include <linux/interrupt.h>
9 #include <linux/slab.h>
10 #include <linux/err.h>
12 #include <linux/sched.h>
13 #include <linux/pm_runtime.h>
18 #define MOD_NAME "OMAP_HDQ:"
20 #define OMAP_HDQ_REVISION 0x00
21 #define OMAP_HDQ_TX_DATA 0x04
22 #define OMAP_HDQ_RX_DATA 0x08
23 #define OMAP_HDQ_CTRL_STATUS 0x0c
24 #define OMAP_HDQ_CTRL_STATUS_SINGLE BIT(7)
25 #define OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK BIT(6)
26 #define OMAP_HDQ_CTRL_STATUS_CLOCKENABLE BIT(5)
27 #define OMAP_HDQ_CTRL_STATUS_GO BIT(4)
28 #define OMAP_HDQ_CTRL_STATUS_PRESENCE BIT(3)
29 #define OMAP_HDQ_CTRL_STATUS_INITIALIZATION BIT(2)
30 #define OMAP_HDQ_CTRL_STATUS_DIR BIT(1)
31 #define OMAP_HDQ_INT_STATUS 0x10
32 #define OMAP_HDQ_INT_STATUS_TXCOMPLETE BIT(2)
33 #define OMAP_HDQ_INT_STATUS_RXCOMPLETE BIT(1)
34 #define OMAP_HDQ_INT_STATUS_TIMEOUT BIT(0)
36 #define OMAP_HDQ_FLAG_CLEAR 0
37 #define OMAP_HDQ_FLAG_SET 1
38 #define OMAP_HDQ_TIMEOUT (HZ/5)
40 #define OMAP_HDQ_MAX_USER 4
42 static DECLARE_WAIT_QUEUE_HEAD(hdq_wait_queue
);
45 module_param(w1_id
, int, 0400);
46 MODULE_PARM_DESC(w1_id
, "1-wire id for the slave detection in HDQ mode");
50 void __iomem
*hdq_base
;
51 /* lock read/write/break operations */
52 struct mutex hdq_mutex
;
53 /* interrupt status and a lock for it */
55 spinlock_t hdq_spinlock
;
56 /* mode: 0-HDQ 1-W1 */
61 /* HDQ register I/O routines */
62 static inline u8
hdq_reg_in(struct hdq_data
*hdq_data
, u32 offset
)
64 return __raw_readl(hdq_data
->hdq_base
+ offset
);
67 static inline void hdq_reg_out(struct hdq_data
*hdq_data
, u32 offset
, u8 val
)
69 __raw_writel(val
, hdq_data
->hdq_base
+ offset
);
72 static inline u8
hdq_reg_merge(struct hdq_data
*hdq_data
, u32 offset
,
75 u8 new_val
= (__raw_readl(hdq_data
->hdq_base
+ offset
) & ~mask
)
77 __raw_writel(new_val
, hdq_data
->hdq_base
+ offset
);
83 * Wait for one or more bits in flag change.
84 * HDQ_FLAG_SET: wait until any bit in the flag is set.
85 * HDQ_FLAG_CLEAR: wait until all bits in the flag are cleared.
86 * return 0 on success and -ETIMEDOUT in the case of timeout.
88 static int hdq_wait_for_flag(struct hdq_data
*hdq_data
, u32 offset
,
89 u8 flag
, u8 flag_set
, u8
*status
)
92 unsigned long timeout
= jiffies
+ OMAP_HDQ_TIMEOUT
;
94 if (flag_set
== OMAP_HDQ_FLAG_CLEAR
) {
95 /* wait for the flag clear */
96 while (((*status
= hdq_reg_in(hdq_data
, offset
)) & flag
)
97 && time_before(jiffies
, timeout
)) {
98 schedule_timeout_uninterruptible(1);
102 } else if (flag_set
== OMAP_HDQ_FLAG_SET
) {
103 /* wait for the flag set */
104 while (!((*status
= hdq_reg_in(hdq_data
, offset
)) & flag
)
105 && time_before(jiffies
, timeout
)) {
106 schedule_timeout_uninterruptible(1);
108 if (!(*status
& flag
))
116 /* Clear saved irqstatus after using an interrupt */
117 static u8
hdq_reset_irqstatus(struct hdq_data
*hdq_data
, u8 bits
)
119 unsigned long irqflags
;
122 spin_lock_irqsave(&hdq_data
->hdq_spinlock
, irqflags
);
123 status
= hdq_data
->hdq_irqstatus
;
124 /* this is a read-modify-write */
125 hdq_data
->hdq_irqstatus
&= ~bits
;
126 spin_unlock_irqrestore(&hdq_data
->hdq_spinlock
, irqflags
);
131 /* write out a byte and fill *status with HDQ_INT_STATUS */
132 static int hdq_write_byte(struct hdq_data
*hdq_data
, u8 val
, u8
*status
)
137 ret
= mutex_lock_interruptible(&hdq_data
->hdq_mutex
);
143 if (hdq_data
->hdq_irqstatus
)
144 dev_err(hdq_data
->dev
, "TX irqstatus not cleared (%02x)\n",
145 hdq_data
->hdq_irqstatus
);
149 hdq_reg_out(hdq_data
, OMAP_HDQ_TX_DATA
, val
);
152 hdq_reg_merge(hdq_data
, OMAP_HDQ_CTRL_STATUS
, OMAP_HDQ_CTRL_STATUS_GO
,
153 OMAP_HDQ_CTRL_STATUS_DIR
| OMAP_HDQ_CTRL_STATUS_GO
);
154 /* wait for the TXCOMPLETE bit */
155 ret
= wait_event_timeout(hdq_wait_queue
,
156 (hdq_data
->hdq_irqstatus
& OMAP_HDQ_INT_STATUS_TXCOMPLETE
),
158 *status
= hdq_reset_irqstatus(hdq_data
, OMAP_HDQ_INT_STATUS_TXCOMPLETE
);
160 dev_dbg(hdq_data
->dev
, "TX wait elapsed\n");
165 /* check irqstatus */
166 if (!(*status
& OMAP_HDQ_INT_STATUS_TXCOMPLETE
)) {
167 dev_dbg(hdq_data
->dev
, "timeout waiting for"
168 " TXCOMPLETE/RXCOMPLETE, %x\n", *status
);
173 /* wait for the GO bit return to zero */
174 ret
= hdq_wait_for_flag(hdq_data
, OMAP_HDQ_CTRL_STATUS
,
175 OMAP_HDQ_CTRL_STATUS_GO
,
176 OMAP_HDQ_FLAG_CLEAR
, &tmp_status
);
178 dev_dbg(hdq_data
->dev
, "timeout waiting GO bit"
179 " return to zero, %x\n", tmp_status
);
183 mutex_unlock(&hdq_data
->hdq_mutex
);
188 /* HDQ Interrupt service routine */
189 static irqreturn_t
hdq_isr(int irq
, void *_hdq
)
191 struct hdq_data
*hdq_data
= _hdq
;
192 unsigned long irqflags
;
194 spin_lock_irqsave(&hdq_data
->hdq_spinlock
, irqflags
);
195 hdq_data
->hdq_irqstatus
|= hdq_reg_in(hdq_data
, OMAP_HDQ_INT_STATUS
);
196 spin_unlock_irqrestore(&hdq_data
->hdq_spinlock
, irqflags
);
197 dev_dbg(hdq_data
->dev
, "hdq_isr: %x\n", hdq_data
->hdq_irqstatus
);
199 if (hdq_data
->hdq_irqstatus
&
200 (OMAP_HDQ_INT_STATUS_TXCOMPLETE
| OMAP_HDQ_INT_STATUS_RXCOMPLETE
201 | OMAP_HDQ_INT_STATUS_TIMEOUT
)) {
202 /* wake up sleeping process */
203 wake_up(&hdq_wait_queue
);
209 /* W1 search callback function in HDQ mode */
210 static void omap_w1_search_bus(void *_hdq
, struct w1_master
*master_dev
,
211 u8 search_type
, w1_slave_found_callback slave_found
)
213 u64 module_id
, rn_le
, cs
, id
;
220 rn_le
= cpu_to_le64(module_id
);
222 * HDQ might not obey truly the 1-wire spec.
223 * So calculate CRC based on module parameter.
225 cs
= w1_calc_crc8((u8
*)&rn_le
, 7);
226 id
= (cs
<< 56) | module_id
;
228 slave_found(master_dev
, id
);
231 /* Issue break pulse to the device */
232 static int omap_hdq_break(struct hdq_data
*hdq_data
)
237 ret
= mutex_lock_interruptible(&hdq_data
->hdq_mutex
);
239 dev_dbg(hdq_data
->dev
, "Could not acquire mutex\n");
244 if (hdq_data
->hdq_irqstatus
)
245 dev_err(hdq_data
->dev
, "break irqstatus not cleared (%02x)\n",
246 hdq_data
->hdq_irqstatus
);
248 /* set the INIT and GO bit */
249 hdq_reg_merge(hdq_data
, OMAP_HDQ_CTRL_STATUS
,
250 OMAP_HDQ_CTRL_STATUS_INITIALIZATION
| OMAP_HDQ_CTRL_STATUS_GO
,
251 OMAP_HDQ_CTRL_STATUS_DIR
| OMAP_HDQ_CTRL_STATUS_INITIALIZATION
|
252 OMAP_HDQ_CTRL_STATUS_GO
);
254 /* wait for the TIMEOUT bit */
255 ret
= wait_event_timeout(hdq_wait_queue
,
256 (hdq_data
->hdq_irqstatus
& OMAP_HDQ_INT_STATUS_TIMEOUT
),
258 tmp_status
= hdq_reset_irqstatus(hdq_data
, OMAP_HDQ_INT_STATUS_TIMEOUT
);
260 dev_dbg(hdq_data
->dev
, "break wait elapsed\n");
265 /* check irqstatus */
266 if (!(tmp_status
& OMAP_HDQ_INT_STATUS_TIMEOUT
)) {
267 dev_dbg(hdq_data
->dev
, "timeout waiting for TIMEOUT, %x\n",
274 * check for the presence detect bit to get
275 * set to show that the slave is responding
277 if (!(hdq_reg_in(hdq_data
, OMAP_HDQ_CTRL_STATUS
) &
278 OMAP_HDQ_CTRL_STATUS_PRESENCE
)) {
279 dev_dbg(hdq_data
->dev
, "Presence bit not set\n");
285 * wait for both INIT and GO bits rerurn to zero.
286 * zero wait time expected for interrupt mode.
288 ret
= hdq_wait_for_flag(hdq_data
, OMAP_HDQ_CTRL_STATUS
,
289 OMAP_HDQ_CTRL_STATUS_INITIALIZATION
|
290 OMAP_HDQ_CTRL_STATUS_GO
, OMAP_HDQ_FLAG_CLEAR
,
293 dev_dbg(hdq_data
->dev
, "timeout waiting INIT&GO bits"
294 " return to zero, %x\n", tmp_status
);
297 mutex_unlock(&hdq_data
->hdq_mutex
);
302 static int hdq_read_byte(struct hdq_data
*hdq_data
, u8
*val
)
307 ret
= mutex_lock_interruptible(&hdq_data
->hdq_mutex
);
313 if (pm_runtime_suspended(hdq_data
->dev
)) {
318 if (!(hdq_data
->hdq_irqstatus
& OMAP_HDQ_INT_STATUS_RXCOMPLETE
)) {
319 hdq_reg_merge(hdq_data
, OMAP_HDQ_CTRL_STATUS
,
320 OMAP_HDQ_CTRL_STATUS_DIR
| OMAP_HDQ_CTRL_STATUS_GO
,
321 OMAP_HDQ_CTRL_STATUS_DIR
| OMAP_HDQ_CTRL_STATUS_GO
);
323 * The RX comes immediately after TX.
325 wait_event_timeout(hdq_wait_queue
,
326 (hdq_data
->hdq_irqstatus
327 & (OMAP_HDQ_INT_STATUS_RXCOMPLETE
|
328 OMAP_HDQ_INT_STATUS_TIMEOUT
)),
330 status
= hdq_reset_irqstatus(hdq_data
,
331 OMAP_HDQ_INT_STATUS_RXCOMPLETE
|
332 OMAP_HDQ_INT_STATUS_TIMEOUT
);
333 hdq_reg_merge(hdq_data
, OMAP_HDQ_CTRL_STATUS
, 0,
334 OMAP_HDQ_CTRL_STATUS_DIR
);
336 /* check irqstatus */
337 if (!(status
& OMAP_HDQ_INT_STATUS_RXCOMPLETE
)) {
338 dev_dbg(hdq_data
->dev
, "timeout waiting for"
339 " RXCOMPLETE, %x", status
);
343 } else { /* interrupt had occurred before hdq_read_byte was called */
344 hdq_reset_irqstatus(hdq_data
, OMAP_HDQ_INT_STATUS_RXCOMPLETE
);
346 /* the data is ready. Read it in! */
347 *val
= hdq_reg_in(hdq_data
, OMAP_HDQ_RX_DATA
);
349 mutex_unlock(&hdq_data
->hdq_mutex
);
356 * W1 triplet callback function - used for searching ROM addresses.
357 * Registered only when controller is in 1-wire mode.
359 static u8
omap_w1_triplet(void *_hdq
, u8 bdir
)
363 u8 ret
= 0x3; /* no slaves responded */
364 struct hdq_data
*hdq_data
= _hdq
;
365 u8 ctrl
= OMAP_HDQ_CTRL_STATUS_SINGLE
| OMAP_HDQ_CTRL_STATUS_GO
|
366 OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK
;
367 u8 mask
= ctrl
| OMAP_HDQ_CTRL_STATUS_DIR
;
369 err
= pm_runtime_get_sync(hdq_data
->dev
);
371 pm_runtime_put_noidle(hdq_data
->dev
);
376 err
= mutex_lock_interruptible(&hdq_data
->hdq_mutex
);
378 dev_dbg(hdq_data
->dev
, "Could not acquire mutex\n");
383 hdq_reg_merge(_hdq
, OMAP_HDQ_CTRL_STATUS
,
384 ctrl
| OMAP_HDQ_CTRL_STATUS_DIR
, mask
);
385 err
= wait_event_timeout(hdq_wait_queue
,
386 (hdq_data
->hdq_irqstatus
387 & OMAP_HDQ_INT_STATUS_RXCOMPLETE
),
389 /* Must clear irqstatus for another RXCOMPLETE interrupt */
390 hdq_reset_irqstatus(hdq_data
, OMAP_HDQ_INT_STATUS_RXCOMPLETE
);
393 dev_dbg(hdq_data
->dev
, "RX wait elapsed\n");
396 id_bit
= (hdq_reg_in(_hdq
, OMAP_HDQ_RX_DATA
) & 0x01);
399 hdq_reg_merge(_hdq
, OMAP_HDQ_CTRL_STATUS
,
400 ctrl
| OMAP_HDQ_CTRL_STATUS_DIR
, mask
);
401 err
= wait_event_timeout(hdq_wait_queue
,
402 (hdq_data
->hdq_irqstatus
403 & OMAP_HDQ_INT_STATUS_RXCOMPLETE
),
405 /* Must clear irqstatus for another RXCOMPLETE interrupt */
406 hdq_reset_irqstatus(hdq_data
, OMAP_HDQ_INT_STATUS_RXCOMPLETE
);
409 dev_dbg(hdq_data
->dev
, "RX wait elapsed\n");
412 comp_bit
= (hdq_reg_in(_hdq
, OMAP_HDQ_RX_DATA
) & 0x01);
414 if (id_bit
&& comp_bit
) {
415 ret
= 0x03; /* no slaves responded */
418 if (!id_bit
&& !comp_bit
) {
419 /* Both bits are valid, take the direction given */
420 ret
= bdir
? 0x04 : 0;
422 /* Only one bit is valid, take that direction */
424 ret
= id_bit
? 0x05 : 0x02;
428 hdq_reg_out(_hdq
, OMAP_HDQ_TX_DATA
, bdir
);
429 hdq_reg_merge(_hdq
, OMAP_HDQ_CTRL_STATUS
, ctrl
, mask
);
430 err
= wait_event_timeout(hdq_wait_queue
,
431 (hdq_data
->hdq_irqstatus
432 & OMAP_HDQ_INT_STATUS_TXCOMPLETE
),
434 /* Must clear irqstatus for another TXCOMPLETE interrupt */
435 hdq_reset_irqstatus(hdq_data
, OMAP_HDQ_INT_STATUS_TXCOMPLETE
);
438 dev_dbg(hdq_data
->dev
, "TX wait elapsed\n");
442 hdq_reg_merge(_hdq
, OMAP_HDQ_CTRL_STATUS
, 0,
443 OMAP_HDQ_CTRL_STATUS_SINGLE
);
446 mutex_unlock(&hdq_data
->hdq_mutex
);
448 pm_runtime_mark_last_busy(hdq_data
->dev
);
449 pm_runtime_put_autosuspend(hdq_data
->dev
);
455 static u8
omap_w1_reset_bus(void *_hdq
)
457 struct hdq_data
*hdq_data
= _hdq
;
460 err
= pm_runtime_get_sync(hdq_data
->dev
);
462 pm_runtime_put_noidle(hdq_data
->dev
);
467 omap_hdq_break(hdq_data
);
469 pm_runtime_mark_last_busy(hdq_data
->dev
);
470 pm_runtime_put_autosuspend(hdq_data
->dev
);
475 /* Read a byte of data from the device */
476 static u8
omap_w1_read_byte(void *_hdq
)
478 struct hdq_data
*hdq_data
= _hdq
;
482 ret
= pm_runtime_get_sync(hdq_data
->dev
);
484 pm_runtime_put_noidle(hdq_data
->dev
);
489 ret
= hdq_read_byte(hdq_data
, &val
);
493 pm_runtime_mark_last_busy(hdq_data
->dev
);
494 pm_runtime_put_autosuspend(hdq_data
->dev
);
499 /* Write a byte of data to the device */
500 static void omap_w1_write_byte(void *_hdq
, u8 byte
)
502 struct hdq_data
*hdq_data
= _hdq
;
506 ret
= pm_runtime_get_sync(hdq_data
->dev
);
508 pm_runtime_put_noidle(hdq_data
->dev
);
514 * We need to reset the slave before
515 * issuing the SKIP ROM command, else
516 * the slave will not work.
518 if (byte
== W1_SKIP_ROM
)
519 omap_hdq_break(hdq_data
);
521 ret
= hdq_write_byte(hdq_data
, byte
, &status
);
523 dev_dbg(hdq_data
->dev
, "TX failure:Ctrl status %x\n", status
);
528 pm_runtime_mark_last_busy(hdq_data
->dev
);
529 pm_runtime_put_autosuspend(hdq_data
->dev
);
532 static struct w1_bus_master omap_w1_master
= {
533 .read_byte
= omap_w1_read_byte
,
534 .write_byte
= omap_w1_write_byte
,
535 .reset_bus
= omap_w1_reset_bus
,
538 static int __maybe_unused
omap_hdq_runtime_suspend(struct device
*dev
)
540 struct hdq_data
*hdq_data
= dev_get_drvdata(dev
);
542 hdq_reg_out(hdq_data
, 0, hdq_data
->mode
);
543 hdq_reg_in(hdq_data
, OMAP_HDQ_INT_STATUS
);
548 static int __maybe_unused
omap_hdq_runtime_resume(struct device
*dev
)
550 struct hdq_data
*hdq_data
= dev_get_drvdata(dev
);
552 /* select HDQ/1W mode & enable clocks */
553 hdq_reg_out(hdq_data
, OMAP_HDQ_CTRL_STATUS
,
554 OMAP_HDQ_CTRL_STATUS_CLOCKENABLE
|
555 OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK
|
557 hdq_reg_in(hdq_data
, OMAP_HDQ_INT_STATUS
);
562 static const struct dev_pm_ops omap_hdq_pm_ops
= {
563 SET_RUNTIME_PM_OPS(omap_hdq_runtime_suspend
,
564 omap_hdq_runtime_resume
, NULL
)
567 static int omap_hdq_probe(struct platform_device
*pdev
)
569 struct device
*dev
= &pdev
->dev
;
570 struct hdq_data
*hdq_data
;
575 hdq_data
= devm_kzalloc(dev
, sizeof(*hdq_data
), GFP_KERNEL
);
580 platform_set_drvdata(pdev
, hdq_data
);
582 hdq_data
->hdq_base
= devm_platform_ioremap_resource(pdev
, 0);
583 if (IS_ERR(hdq_data
->hdq_base
))
584 return PTR_ERR(hdq_data
->hdq_base
);
586 mutex_init(&hdq_data
->hdq_mutex
);
588 ret
= of_property_read_string(pdev
->dev
.of_node
, "ti,mode", &mode
);
589 if (ret
< 0 || !strcmp(mode
, "hdq")) {
591 omap_w1_master
.search
= omap_w1_search_bus
;
594 omap_w1_master
.triplet
= omap_w1_triplet
;
597 pm_runtime_enable(&pdev
->dev
);
598 pm_runtime_use_autosuspend(&pdev
->dev
);
599 pm_runtime_set_autosuspend_delay(&pdev
->dev
, 300);
600 ret
= pm_runtime_get_sync(&pdev
->dev
);
602 pm_runtime_put_noidle(&pdev
->dev
);
603 dev_dbg(&pdev
->dev
, "pm_runtime_get_sync failed\n");
607 rev
= hdq_reg_in(hdq_data
, OMAP_HDQ_REVISION
);
608 dev_info(&pdev
->dev
, "OMAP HDQ Hardware Rev %c.%c. Driver in %s mode\n",
609 (rev
>> 4) + '0', (rev
& 0x0f) + '0', "Interrupt");
611 spin_lock_init(&hdq_data
->hdq_spinlock
);
613 irq
= platform_get_irq(pdev
, 0);
615 dev_dbg(&pdev
->dev
, "Failed to get IRQ: %d\n", irq
);
620 ret
= devm_request_irq(dev
, irq
, hdq_isr
, 0, "omap_hdq", hdq_data
);
622 dev_dbg(&pdev
->dev
, "could not request irq\n");
626 omap_hdq_break(hdq_data
);
628 pm_runtime_mark_last_busy(&pdev
->dev
);
629 pm_runtime_put_autosuspend(&pdev
->dev
);
631 omap_w1_master
.data
= hdq_data
;
633 ret
= w1_add_master_device(&omap_w1_master
);
635 dev_dbg(&pdev
->dev
, "Failure in registering w1 master\n");
642 pm_runtime_put_sync(&pdev
->dev
);
644 pm_runtime_dont_use_autosuspend(&pdev
->dev
);
645 pm_runtime_disable(&pdev
->dev
);
650 static void omap_hdq_remove(struct platform_device
*pdev
)
654 active
= pm_runtime_get_sync(&pdev
->dev
);
656 pm_runtime_put_noidle(&pdev
->dev
);
658 w1_remove_master_device(&omap_w1_master
);
660 pm_runtime_dont_use_autosuspend(&pdev
->dev
);
662 pm_runtime_put_sync(&pdev
->dev
);
663 pm_runtime_disable(&pdev
->dev
);
666 static const struct of_device_id omap_hdq_dt_ids
[] = {
667 { .compatible
= "ti,omap3-1w" },
668 { .compatible
= "ti,am4372-hdq" },
671 MODULE_DEVICE_TABLE(of
, omap_hdq_dt_ids
);
673 static struct platform_driver omap_hdq_driver
= {
674 .probe
= omap_hdq_probe
,
675 .remove
= omap_hdq_remove
,
678 .of_match_table
= omap_hdq_dt_ids
,
679 .pm
= &omap_hdq_pm_ops
,
682 module_platform_driver(omap_hdq_driver
);
684 MODULE_AUTHOR("Texas Instruments");
685 MODULE_DESCRIPTION("HDQ-1W driver Library");
686 MODULE_LICENSE("GPL");