2 * Copyright (C) 2011-2012 Freescale Semiconductor, Inc.
4 * The code contained herein is licensed under the GNU General Public
5 * License. You may obtain a copy of the GNU General Public License
6 * Version 2 or later at the following locations:
8 * http://www.opensource.org/licenses/gpl-license.html
9 * http://www.gnu.org/copyleft/gpl.html
12 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
17 #include <linux/of_device.h>
18 #include <linux/platform_device.h>
19 #include <linux/rtc.h>
20 #include <linux/clk.h>
21 #include <linux/mfd/syscon.h>
22 #include <linux/regmap.h>
24 #define SNVS_LPREGISTER_OFFSET 0x34
26 /* These register offsets are relative to LP (Low Power) range */
27 #define SNVS_LPCR 0x04
28 #define SNVS_LPSR 0x18
29 #define SNVS_LPSRTCMR 0x1c
30 #define SNVS_LPSRTCLR 0x20
31 #define SNVS_LPTAR 0x24
32 #define SNVS_LPPGDR 0x30
34 #define SNVS_LPCR_SRTC_ENV (1 << 0)
35 #define SNVS_LPCR_LPTA_EN (1 << 1)
36 #define SNVS_LPCR_LPWUI_EN (1 << 3)
37 #define SNVS_LPSR_LPTA (1 << 0)
39 #define SNVS_LPPGDR_INIT 0x41736166
40 #define CNTR_TO_SECS_SH 15
42 struct snvs_rtc_data
{
43 struct rtc_device
*rtc
;
44 struct regmap
*regmap
;
50 static u32
rtc_read_lp_counter(struct snvs_rtc_data
*data
)
56 regmap_read(data
->regmap
, data
->offset
+ SNVS_LPSRTCMR
, &val
);
59 regmap_read(data
->regmap
, data
->offset
+ SNVS_LPSRTCLR
, &val
);
62 regmap_read(data
->regmap
, data
->offset
+ SNVS_LPSRTCMR
, &val
);
65 regmap_read(data
->regmap
, data
->offset
+ SNVS_LPSRTCLR
, &val
);
67 } while (read1
!= read2
);
69 /* Convert 47-bit counter to 32-bit raw second count */
70 return (u32
) (read1
>> CNTR_TO_SECS_SH
);
73 static void rtc_write_sync_lp(struct snvs_rtc_data
*data
)
75 u32 count1
, count2
, count3
;
78 /* Wait for 3 CKIL cycles */
79 for (i
= 0; i
< 3; i
++) {
81 regmap_read(data
->regmap
, data
->offset
+ SNVS_LPSRTCLR
, &count1
);
82 regmap_read(data
->regmap
, data
->offset
+ SNVS_LPSRTCLR
, &count2
);
83 } while (count1
!= count2
);
85 /* Now wait until counter value changes */
88 regmap_read(data
->regmap
, data
->offset
+ SNVS_LPSRTCLR
, &count2
);
89 regmap_read(data
->regmap
, data
->offset
+ SNVS_LPSRTCLR
, &count3
);
90 } while (count2
!= count3
);
91 } while (count3
== count1
);
95 static int snvs_rtc_enable(struct snvs_rtc_data
*data
, bool enable
)
100 regmap_update_bits(data
->regmap
, data
->offset
+ SNVS_LPCR
, SNVS_LPCR_SRTC_ENV
,
101 enable
? SNVS_LPCR_SRTC_ENV
: 0);
104 regmap_read(data
->regmap
, data
->offset
+ SNVS_LPCR
, &lpcr
);
107 if (lpcr
& SNVS_LPCR_SRTC_ENV
)
110 if (!(lpcr
& SNVS_LPCR_SRTC_ENV
))
121 static int snvs_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
123 struct snvs_rtc_data
*data
= dev_get_drvdata(dev
);
124 unsigned long time
= rtc_read_lp_counter(data
);
126 rtc_time_to_tm(time
, tm
);
131 static int snvs_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
133 struct snvs_rtc_data
*data
= dev_get_drvdata(dev
);
136 rtc_tm_to_time(tm
, &time
);
138 /* Disable RTC first */
139 snvs_rtc_enable(data
, false);
141 /* Write 32-bit time to 47-bit timer, leaving 15 LSBs blank */
142 regmap_write(data
->regmap
, data
->offset
+ SNVS_LPSRTCLR
, time
<< CNTR_TO_SECS_SH
);
143 regmap_write(data
->regmap
, data
->offset
+ SNVS_LPSRTCMR
, time
>> (32 - CNTR_TO_SECS_SH
));
145 /* Enable RTC again */
146 snvs_rtc_enable(data
, true);
151 static int snvs_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
153 struct snvs_rtc_data
*data
= dev_get_drvdata(dev
);
156 regmap_read(data
->regmap
, data
->offset
+ SNVS_LPTAR
, &lptar
);
157 rtc_time_to_tm(lptar
, &alrm
->time
);
159 regmap_read(data
->regmap
, data
->offset
+ SNVS_LPSR
, &lpsr
);
160 alrm
->pending
= (lpsr
& SNVS_LPSR_LPTA
) ? 1 : 0;
165 static int snvs_rtc_alarm_irq_enable(struct device
*dev
, unsigned int enable
)
167 struct snvs_rtc_data
*data
= dev_get_drvdata(dev
);
169 regmap_update_bits(data
->regmap
, data
->offset
+ SNVS_LPCR
,
170 (SNVS_LPCR_LPTA_EN
| SNVS_LPCR_LPWUI_EN
),
171 enable
? (SNVS_LPCR_LPTA_EN
| SNVS_LPCR_LPWUI_EN
) : 0);
173 rtc_write_sync_lp(data
);
178 static int snvs_rtc_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
180 struct snvs_rtc_data
*data
= dev_get_drvdata(dev
);
181 struct rtc_time
*alrm_tm
= &alrm
->time
;
184 rtc_tm_to_time(alrm_tm
, &time
);
186 regmap_update_bits(data
->regmap
, data
->offset
+ SNVS_LPCR
, SNVS_LPCR_LPTA_EN
, 0);
187 rtc_write_sync_lp(data
);
188 regmap_write(data
->regmap
, data
->offset
+ SNVS_LPTAR
, time
);
190 /* Clear alarm interrupt status bit */
191 regmap_write(data
->regmap
, data
->offset
+ SNVS_LPSR
, SNVS_LPSR_LPTA
);
193 return snvs_rtc_alarm_irq_enable(dev
, alrm
->enabled
);
196 static const struct rtc_class_ops snvs_rtc_ops
= {
197 .read_time
= snvs_rtc_read_time
,
198 .set_time
= snvs_rtc_set_time
,
199 .read_alarm
= snvs_rtc_read_alarm
,
200 .set_alarm
= snvs_rtc_set_alarm
,
201 .alarm_irq_enable
= snvs_rtc_alarm_irq_enable
,
204 static irqreturn_t
snvs_rtc_irq_handler(int irq
, void *dev_id
)
206 struct device
*dev
= dev_id
;
207 struct snvs_rtc_data
*data
= dev_get_drvdata(dev
);
211 regmap_read(data
->regmap
, data
->offset
+ SNVS_LPSR
, &lpsr
);
213 if (lpsr
& SNVS_LPSR_LPTA
) {
214 events
|= (RTC_AF
| RTC_IRQF
);
216 /* RTC alarm should be one-shot */
217 snvs_rtc_alarm_irq_enable(dev
, 0);
219 rtc_update_irq(data
->rtc
, 1, events
);
222 /* clear interrupt status */
223 regmap_write(data
->regmap
, data
->offset
+ SNVS_LPSR
, lpsr
);
225 return events
? IRQ_HANDLED
: IRQ_NONE
;
228 static const struct regmap_config snvs_rtc_config
= {
234 static int snvs_rtc_probe(struct platform_device
*pdev
)
236 struct snvs_rtc_data
*data
;
237 struct resource
*res
;
241 data
= devm_kzalloc(&pdev
->dev
, sizeof(*data
), GFP_KERNEL
);
245 data
->regmap
= syscon_regmap_lookup_by_phandle(pdev
->dev
.of_node
, "regmap");
247 if (IS_ERR(data
->regmap
)) {
248 dev_warn(&pdev
->dev
, "snvs rtc: you use old dts file, please update it\n");
249 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
251 mmio
= devm_ioremap_resource(&pdev
->dev
, res
);
253 return PTR_ERR(mmio
);
255 data
->regmap
= devm_regmap_init_mmio(&pdev
->dev
, mmio
, &snvs_rtc_config
);
257 data
->offset
= SNVS_LPREGISTER_OFFSET
;
258 of_property_read_u32(pdev
->dev
.of_node
, "offset", &data
->offset
);
262 dev_err(&pdev
->dev
, "Can't find snvs syscon\n");
266 data
->irq
= platform_get_irq(pdev
, 0);
270 data
->clk
= devm_clk_get(&pdev
->dev
, "snvs-rtc");
271 if (IS_ERR(data
->clk
)) {
274 ret
= clk_prepare_enable(data
->clk
);
277 "Could not prepare or enable the snvs clock\n");
282 platform_set_drvdata(pdev
, data
);
284 /* Initialize glitch detect */
285 regmap_write(data
->regmap
, data
->offset
+ SNVS_LPPGDR
, SNVS_LPPGDR_INIT
);
287 /* Clear interrupt status */
288 regmap_write(data
->regmap
, data
->offset
+ SNVS_LPSR
, 0xffffffff);
291 snvs_rtc_enable(data
, true);
293 device_init_wakeup(&pdev
->dev
, true);
295 ret
= devm_request_irq(&pdev
->dev
, data
->irq
, snvs_rtc_irq_handler
,
296 IRQF_SHARED
, "rtc alarm", &pdev
->dev
);
298 dev_err(&pdev
->dev
, "failed to request irq %d: %d\n",
300 goto error_rtc_device_register
;
303 data
->rtc
= devm_rtc_device_register(&pdev
->dev
, pdev
->name
,
304 &snvs_rtc_ops
, THIS_MODULE
);
305 if (IS_ERR(data
->rtc
)) {
306 ret
= PTR_ERR(data
->rtc
);
307 dev_err(&pdev
->dev
, "failed to register rtc: %d\n", ret
);
308 goto error_rtc_device_register
;
313 error_rtc_device_register
:
315 clk_disable_unprepare(data
->clk
);
320 #ifdef CONFIG_PM_SLEEP
321 static int snvs_rtc_suspend(struct device
*dev
)
323 struct snvs_rtc_data
*data
= dev_get_drvdata(dev
);
325 if (device_may_wakeup(dev
))
326 return enable_irq_wake(data
->irq
);
331 static int snvs_rtc_suspend_noirq(struct device
*dev
)
333 struct snvs_rtc_data
*data
= dev_get_drvdata(dev
);
336 clk_disable_unprepare(data
->clk
);
341 static int snvs_rtc_resume(struct device
*dev
)
343 struct snvs_rtc_data
*data
= dev_get_drvdata(dev
);
345 if (device_may_wakeup(dev
))
346 return disable_irq_wake(data
->irq
);
351 static int snvs_rtc_resume_noirq(struct device
*dev
)
353 struct snvs_rtc_data
*data
= dev_get_drvdata(dev
);
356 return clk_prepare_enable(data
->clk
);
361 static const struct dev_pm_ops snvs_rtc_pm_ops
= {
362 .suspend
= snvs_rtc_suspend
,
363 .suspend_noirq
= snvs_rtc_suspend_noirq
,
364 .resume
= snvs_rtc_resume
,
365 .resume_noirq
= snvs_rtc_resume_noirq
,
368 #define SNVS_RTC_PM_OPS (&snvs_rtc_pm_ops)
372 #define SNVS_RTC_PM_OPS NULL
376 static const struct of_device_id snvs_dt_ids
[] = {
377 { .compatible
= "fsl,sec-v4.0-mon-rtc-lp", },
380 MODULE_DEVICE_TABLE(of
, snvs_dt_ids
);
382 static struct platform_driver snvs_rtc_driver
= {
385 .pm
= SNVS_RTC_PM_OPS
,
386 .of_match_table
= snvs_dt_ids
,
388 .probe
= snvs_rtc_probe
,
390 module_platform_driver(snvs_rtc_driver
);
392 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
393 MODULE_DESCRIPTION("Freescale SNVS RTC Driver");
394 MODULE_LICENSE("GPL");