linux/drivers/rtc/rtc-snvs.c
Linus Torvalds e6b5be2be4 Driver core patches for 3.19-rc1
Here's the set of driver core patches for 3.19-rc1.
 
 They are dominated by the removal of the .owner field in platform
 drivers.  They touch a lot of files, but they are "simple" changes, just
 removing a line in a structure.
 
 Other than that, a few minor driver core and debugfs changes.  There are
 some ath9k patches coming in through this tree that have been acked by
 the wireless maintainers as they relied on the debugfs changes.
 
 Everything has been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core update from Greg KH:
 "Here's the set of driver core patches for 3.19-rc1.

  They are dominated by the removal of the .owner field in platform
  drivers.  They touch a lot of files, but they are "simple" changes,
  just removing a line in a structure.

  Other than that, a few minor driver core and debugfs changes.  There
  are some ath9k patches coming in through this tree that have been
  acked by the wireless maintainers as they relied on the debugfs
  changes.

  Everything has been in linux-next for a while"

* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
  Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
  fs: debugfs: add forward declaration for struct device type
  firmware class: Deletion of an unnecessary check before the function call "vunmap"
  firmware loader: fix hung task warning dump
  devcoredump: provide a one-way disable function
  device: Add dev_<level>_once variants
  ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
  ath: use seq_file api for ath9k debugfs files
  debugfs: add helper function to create device related seq_file
  drivers/base: cacheinfo: remove noisy error boot message
  Revert "core: platform: add warning if driver has no owner"
  drivers: base: support cpu cache information interface to userspace via sysfs
  drivers: base: add cpu_device_create to support per-cpu devices
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  cpumask: factor out show_cpumap into separate helper function
  driver core: Fix unbalanced device reference in drivers_probe
  driver core: fix race with userland in device_add()
  sysfs/kernfs: make read requests on pre-alloc files use the buffer.
  sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
  fs: sysfs: return EGBIG on write if offset is larger than file size
  ...
2014-12-14 16:10:09 -08:00

380 lines
8.4 KiB
C

/*
* Copyright (C) 2011-2012 Freescale Semiconductor, Inc.
*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/clk.h>
/* These register offsets are relative to LP (Low Power) range */
#define SNVS_LPCR 0x04
#define SNVS_LPSR 0x18
#define SNVS_LPSRTCMR 0x1c
#define SNVS_LPSRTCLR 0x20
#define SNVS_LPTAR 0x24
#define SNVS_LPPGDR 0x30
#define SNVS_LPCR_SRTC_ENV (1 << 0)
#define SNVS_LPCR_LPTA_EN (1 << 1)
#define SNVS_LPCR_LPWUI_EN (1 << 3)
#define SNVS_LPSR_LPTA (1 << 0)
#define SNVS_LPPGDR_INIT 0x41736166
#define CNTR_TO_SECS_SH 15
struct snvs_rtc_data {
struct rtc_device *rtc;
void __iomem *ioaddr;
int irq;
spinlock_t lock;
struct clk *clk;
};
static u32 rtc_read_lp_counter(void __iomem *ioaddr)
{
u64 read1, read2;
do {
read1 = readl(ioaddr + SNVS_LPSRTCMR);
read1 <<= 32;
read1 |= readl(ioaddr + SNVS_LPSRTCLR);
read2 = readl(ioaddr + SNVS_LPSRTCMR);
read2 <<= 32;
read2 |= readl(ioaddr + SNVS_LPSRTCLR);
} while (read1 != read2);
/* Convert 47-bit counter to 32-bit raw second count */
return (u32) (read1 >> CNTR_TO_SECS_SH);
}
static void rtc_write_sync_lp(void __iomem *ioaddr)
{
u32 count1, count2, count3;
int i;
/* Wait for 3 CKIL cycles */
for (i = 0; i < 3; i++) {
do {
count1 = readl(ioaddr + SNVS_LPSRTCLR);
count2 = readl(ioaddr + SNVS_LPSRTCLR);
} while (count1 != count2);
/* Now wait until counter value changes */
do {
do {
count2 = readl(ioaddr + SNVS_LPSRTCLR);
count3 = readl(ioaddr + SNVS_LPSRTCLR);
} while (count2 != count3);
} while (count3 == count1);
}
}
static int snvs_rtc_enable(struct snvs_rtc_data *data, bool enable)
{
unsigned long flags;
int timeout = 1000;
u32 lpcr;
spin_lock_irqsave(&data->lock, flags);
lpcr = readl(data->ioaddr + SNVS_LPCR);
if (enable)
lpcr |= SNVS_LPCR_SRTC_ENV;
else
lpcr &= ~SNVS_LPCR_SRTC_ENV;
writel(lpcr, data->ioaddr + SNVS_LPCR);
spin_unlock_irqrestore(&data->lock, flags);
while (--timeout) {
lpcr = readl(data->ioaddr + SNVS_LPCR);
if (enable) {
if (lpcr & SNVS_LPCR_SRTC_ENV)
break;
} else {
if (!(lpcr & SNVS_LPCR_SRTC_ENV))
break;
}
}
if (!timeout)
return -ETIMEDOUT;
return 0;
}
static int snvs_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct snvs_rtc_data *data = dev_get_drvdata(dev);
unsigned long time = rtc_read_lp_counter(data->ioaddr);
rtc_time_to_tm(time, tm);
return 0;
}
static int snvs_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct snvs_rtc_data *data = dev_get_drvdata(dev);
unsigned long time;
rtc_tm_to_time(tm, &time);
/* Disable RTC first */
snvs_rtc_enable(data, false);
/* Write 32-bit time to 47-bit timer, leaving 15 LSBs blank */
writel(time << CNTR_TO_SECS_SH, data->ioaddr + SNVS_LPSRTCLR);
writel(time >> (32 - CNTR_TO_SECS_SH), data->ioaddr + SNVS_LPSRTCMR);
/* Enable RTC again */
snvs_rtc_enable(data, true);
return 0;
}
static int snvs_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct snvs_rtc_data *data = dev_get_drvdata(dev);
u32 lptar, lpsr;
lptar = readl(data->ioaddr + SNVS_LPTAR);
rtc_time_to_tm(lptar, &alrm->time);
lpsr = readl(data->ioaddr + SNVS_LPSR);
alrm->pending = (lpsr & SNVS_LPSR_LPTA) ? 1 : 0;
return 0;
}
static int snvs_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
{
struct snvs_rtc_data *data = dev_get_drvdata(dev);
u32 lpcr;
unsigned long flags;
spin_lock_irqsave(&data->lock, flags);
lpcr = readl(data->ioaddr + SNVS_LPCR);
if (enable)
lpcr |= (SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN);
else
lpcr &= ~(SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN);
writel(lpcr, data->ioaddr + SNVS_LPCR);
spin_unlock_irqrestore(&data->lock, flags);
rtc_write_sync_lp(data->ioaddr);
return 0;
}
static int snvs_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct snvs_rtc_data *data = dev_get_drvdata(dev);
struct rtc_time *alrm_tm = &alrm->time;
unsigned long time;
unsigned long flags;
u32 lpcr;
rtc_tm_to_time(alrm_tm, &time);
spin_lock_irqsave(&data->lock, flags);
/* Have to clear LPTA_EN before programming new alarm time in LPTAR */
lpcr = readl(data->ioaddr + SNVS_LPCR);
lpcr &= ~SNVS_LPCR_LPTA_EN;
writel(lpcr, data->ioaddr + SNVS_LPCR);
spin_unlock_irqrestore(&data->lock, flags);
writel(time, data->ioaddr + SNVS_LPTAR);
/* Clear alarm interrupt status bit */
writel(SNVS_LPSR_LPTA, data->ioaddr + SNVS_LPSR);
return snvs_rtc_alarm_irq_enable(dev, alrm->enabled);
}
static const struct rtc_class_ops snvs_rtc_ops = {
.read_time = snvs_rtc_read_time,
.set_time = snvs_rtc_set_time,
.read_alarm = snvs_rtc_read_alarm,
.set_alarm = snvs_rtc_set_alarm,
.alarm_irq_enable = snvs_rtc_alarm_irq_enable,
};
static irqreturn_t snvs_rtc_irq_handler(int irq, void *dev_id)
{
struct device *dev = dev_id;
struct snvs_rtc_data *data = dev_get_drvdata(dev);
u32 lpsr;
u32 events = 0;
lpsr = readl(data->ioaddr + SNVS_LPSR);
if (lpsr & SNVS_LPSR_LPTA) {
events |= (RTC_AF | RTC_IRQF);
/* RTC alarm should be one-shot */
snvs_rtc_alarm_irq_enable(dev, 0);
rtc_update_irq(data->rtc, 1, events);
}
/* clear interrupt status */
writel(lpsr, data->ioaddr + SNVS_LPSR);
return events ? IRQ_HANDLED : IRQ_NONE;
}
static int snvs_rtc_probe(struct platform_device *pdev)
{
struct snvs_rtc_data *data;
struct resource *res;
int ret;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
data->ioaddr = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(data->ioaddr))
return PTR_ERR(data->ioaddr);
data->irq = platform_get_irq(pdev, 0);
if (data->irq < 0)
return data->irq;
data->clk = devm_clk_get(&pdev->dev, "snvs-rtc");
if (IS_ERR(data->clk)) {
data->clk = NULL;
} else {
ret = clk_prepare_enable(data->clk);
if (ret) {
dev_err(&pdev->dev,
"Could not prepare or enable the snvs clock\n");
return ret;
}
}
platform_set_drvdata(pdev, data);
spin_lock_init(&data->lock);
/* Initialize glitch detect */
writel(SNVS_LPPGDR_INIT, data->ioaddr + SNVS_LPPGDR);
/* Clear interrupt status */
writel(0xffffffff, data->ioaddr + SNVS_LPSR);
/* Enable RTC */
snvs_rtc_enable(data, true);
device_init_wakeup(&pdev->dev, true);
ret = devm_request_irq(&pdev->dev, data->irq, snvs_rtc_irq_handler,
IRQF_SHARED, "rtc alarm", &pdev->dev);
if (ret) {
dev_err(&pdev->dev, "failed to request irq %d: %d\n",
data->irq, ret);
goto error_rtc_device_register;
}
data->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
&snvs_rtc_ops, THIS_MODULE);
if (IS_ERR(data->rtc)) {
ret = PTR_ERR(data->rtc);
dev_err(&pdev->dev, "failed to register rtc: %d\n", ret);
goto error_rtc_device_register;
}
return 0;
error_rtc_device_register:
if (data->clk)
clk_disable_unprepare(data->clk);
return ret;
}
#ifdef CONFIG_PM_SLEEP
static int snvs_rtc_suspend(struct device *dev)
{
struct snvs_rtc_data *data = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
enable_irq_wake(data->irq);
if (data->clk)
clk_disable_unprepare(data->clk);
return 0;
}
static int snvs_rtc_resume(struct device *dev)
{
struct snvs_rtc_data *data = dev_get_drvdata(dev);
int ret;
if (device_may_wakeup(dev))
disable_irq_wake(data->irq);
if (data->clk) {
ret = clk_prepare_enable(data->clk);
if (ret)
return ret;
}
return 0;
}
static const struct dev_pm_ops snvs_rtc_pm_ops = {
.suspend_noirq = snvs_rtc_suspend,
.resume_noirq = snvs_rtc_resume,
};
#define SNVS_RTC_PM_OPS (&snvs_rtc_pm_ops)
#else
#define SNVS_RTC_PM_OPS NULL
#endif
static const struct of_device_id snvs_dt_ids[] = {
{ .compatible = "fsl,sec-v4.0-mon-rtc-lp", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, snvs_dt_ids);
static struct platform_driver snvs_rtc_driver = {
.driver = {
.name = "snvs_rtc",
.pm = SNVS_RTC_PM_OPS,
.of_match_table = snvs_dt_ids,
},
.probe = snvs_rtc_probe,
};
module_platform_driver(snvs_rtc_driver);
MODULE_AUTHOR("Freescale Semiconductor, Inc.");
MODULE_DESCRIPTION("Freescale SNVS RTC Driver");
MODULE_LICENSE("GPL");