| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Baruch Siach | 1520 | 48.09% | 1 | 4.35% |
| Juergen Beisert (or Jourgen Borleis) | 1471 | 46.54% | 6 | 26.09% |
| Martin Kaiser | 73 | 2.31% | 2 | 8.70% |
| Roland Stigge | 41 | 1.30% | 1 | 4.35% |
| Julia Lawall | 16 | 0.51% | 1 | 4.35% |
| Jingoo Han | 11 | 0.35% | 4 | 17.39% |
| Fabio Estevam | 9 | 0.28% | 1 | 4.35% |
| Jan Lübbe | 8 | 0.25% | 1 | 4.35% |
| Sascha Hauer | 3 | 0.09% | 1 | 4.35% |
| Jean Delvare | 3 | 0.09% | 1 | 4.35% |
| Axel Lin | 3 | 0.09% | 1 | 4.35% |
| Colin Ian King | 1 | 0.03% | 1 | 4.35% |
| Ingo Molnar | 1 | 0.03% | 1 | 4.35% |
| Bhumika Goyal | 1 | 0.03% | 1 | 4.35% |
| Total | 3161 | 23 |
/* * Copyright 2008-2009 Freescale Semiconductor, Inc. All Rights Reserved. * Copyright 2010 Orex Computed Radiography */ /* * 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 */ /* based on rtc-mc13892.c */ /* * This driver uses the 47-bit 32 kHz counter in the Freescale DryIce block * to implement a Linux RTC. Times and alarms are truncated to seconds. * Since the RTC framework performs API locking via rtc->ops_lock the * only simultaneous accesses we need to deal with is updating DryIce * registers while servicing an alarm. * * Note that reading the DSR (DryIce Status Register) automatically clears * the WCF (Write Complete Flag). All DryIce writes are synchronized to the * LP (Low Power) domain and set the WCF upon completion. Writes to the * DIER (DryIce Interrupt Enable Register) are the only exception. These * occur at normal bus speeds and do not set WCF. Periodic interrupts are * not supported by the hardware. */ #include <linux/io.h> #include <linux/clk.h> #include <linux/delay.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/rtc.h> #include <linux/sched.h> #include <linux/spinlock.h> #include <linux/workqueue.h> #include <linux/of.h> /* DryIce Register Definitions */ #define DTCMR 0x00 /* Time Counter MSB Reg */ #define DTCLR 0x04 /* Time Counter LSB Reg */ #define DCAMR 0x08 /* Clock Alarm MSB Reg */ #define DCALR 0x0c /* Clock Alarm LSB Reg */ #define DCAMR_UNSET 0xFFFFFFFF /* doomsday - 1 sec */ #define DCR 0x10 /* Control Reg */ #define DCR_TDCHL (1 << 30) /* Tamper-detect configuration hard lock */ #define DCR_TDCSL (1 << 29) /* Tamper-detect configuration soft lock */ #define DCR_KSSL (1 << 27) /* Key-select soft lock */ #define DCR_MCHL (1 << 20) /* Monotonic-counter hard lock */ #define DCR_MCSL (1 << 19) /* Monotonic-counter soft lock */ #define DCR_TCHL (1 << 18) /* Timer-counter hard lock */ #define DCR_TCSL (1 << 17) /* Timer-counter soft lock */ #define DCR_FSHL (1 << 16) /* Failure state hard lock */ #define DCR_TCE (1 << 3) /* Time Counter Enable */ #define DCR_MCE (1 << 2) /* Monotonic Counter Enable */ #define DSR 0x14 /* Status Reg */ #define DSR_WTD (1 << 23) /* Wire-mesh tamper detected */ #define DSR_ETBD (1 << 22) /* External tamper B detected */ #define DSR_ETAD (1 << 21) /* External tamper A detected */ #define DSR_EBD (1 << 20) /* External boot detected */ #define DSR_SAD (1 << 19) /* SCC alarm detected */ #define DSR_TTD (1 << 18) /* Temperature tamper detected */ #define DSR_CTD (1 << 17) /* Clock tamper detected */ #define DSR_VTD (1 << 16) /* Voltage tamper detected */ #define DSR_WBF (1 << 10) /* Write Busy Flag (synchronous) */ #define DSR_WNF (1 << 9) /* Write Next Flag (synchronous) */ #define DSR_WCF (1 << 8) /* Write Complete Flag (synchronous)*/ #define DSR_WEF (1 << 7) /* Write Error Flag */ #define DSR_CAF (1 << 4) /* Clock Alarm Flag */ #define DSR_MCO (1 << 3) /* monotonic counter overflow */ #define DSR_TCO (1 << 2) /* time counter overflow */ #define DSR_NVF (1 << 1) /* Non-Valid Flag */ #define DSR_SVF (1 << 0) /* Security Violation Flag */ #define DIER 0x18 /* Interrupt Enable Reg (synchronous) */ #define DIER_WNIE (1 << 9) /* Write Next Interrupt Enable */ #define DIER_WCIE (1 << 8) /* Write Complete Interrupt Enable */ #define DIER_WEIE (1 << 7) /* Write Error Interrupt Enable */ #define DIER_CAIE (1 << 4) /* Clock Alarm Interrupt Enable */ #define DIER_SVIE (1 << 0) /* Security-violation Interrupt Enable */ #define DMCR 0x1c /* DryIce Monotonic Counter Reg */ #define DTCR 0x28 /* DryIce Tamper Configuration Reg */ #define DTCR_MOE (1 << 9) /* monotonic overflow enabled */ #define DTCR_TOE (1 << 8) /* time overflow enabled */ #define DTCR_WTE (1 << 7) /* wire-mesh tamper enabled */ #define DTCR_ETBE (1 << 6) /* external B tamper enabled */ #define DTCR_ETAE (1 << 5) /* external A tamper enabled */ #define DTCR_EBE (1 << 4) /* external boot tamper enabled */ #define DTCR_SAIE (1 << 3) /* SCC enabled */ #define DTCR_TTE (1 << 2) /* temperature tamper enabled */ #define DTCR_CTE (1 << 1) /* clock tamper enabled */ #define DTCR_VTE (1 << 0) /* voltage tamper enabled */ #define DGPR 0x3c /* DryIce General Purpose Reg */ /** * struct imxdi_dev - private imxdi rtc data * @pdev: pionter to platform dev * @rtc: pointer to rtc struct * @ioaddr: IO registers pointer * @clk: input reference clock * @dsr: copy of the DSR register * @irq_lock: interrupt enable register (DIER) lock * @write_wait: registers write complete queue * @write_mutex: serialize registers write * @work: schedule alarm work */ struct imxdi_dev { struct platform_device *pdev; struct rtc_device *rtc; void __iomem *ioaddr; struct clk *clk; u32 dsr; spinlock_t irq_lock; wait_queue_head_t write_wait; struct mutex write_mutex; struct work_struct work; }; /* Some background: * * The DryIce unit is a complex security/tamper monitor device. To be able do * its job in a useful manner it runs a bigger statemachine to bring it into * security/tamper failure state and once again to bring it out of this state. * * This unit can be in one of three states: * * - "NON-VALID STATE" * always after the battery power was removed * - "FAILURE STATE" * if one of the enabled security events has happened * - "VALID STATE" * if the unit works as expected * * Everything stops when the unit enters the failure state including the RTC * counter (to be able to detect the time the security event happened). * * The following events (when enabled) let the DryIce unit enter the failure * state: * * - wire-mesh-tamper detect * - external tamper B detect * - external tamper A detect * - temperature tamper detect * - clock tamper detect * - voltage tamper detect * - RTC counter overflow * - monotonic counter overflow * - external boot * * If we find the DryIce unit in "FAILURE STATE" and the TDCHL cleared, we * can only detect this state. In this case the unit is completely locked and * must force a second "SYSTEM POR" to bring the DryIce into the * "NON-VALID STATE" + "FAILURE STATE" where a recovery is possible. * If the TDCHL is set in the "FAILURE STATE" we are out of luck. In this case * a battery power cycle is required. * * In the "NON-VALID STATE" + "FAILURE STATE" we can clear the "FAILURE STATE" * and recover the DryIce unit. By clearing the "NON-VALID STATE" as the last * task, we bring back this unit into life. */ /* * Do a write into the unit without interrupt support. * We do not need to check the WEF here, because the only reason this kind of * write error can happen is if we write to the unit twice within the 122 us * interval. This cannot happen, since we are using this function only while * setting up the unit. */ static void di_write_busy_wait(const struct imxdi_dev *imxdi, u32 val, unsigned reg) { /* do the register write */ writel(val, imxdi->ioaddr + reg); /* * now it takes four 32,768 kHz clock cycles to take * the change into effect = 122 us */ usleep_range(130, 200); } static void di_report_tamper_info(struct imxdi_dev *imxdi, u32 dsr) { u32 dtcr; dtcr = readl(imxdi->ioaddr + DTCR); dev_emerg(&imxdi->pdev->dev, "DryIce tamper event detected\n"); /* the following flags force a transition into the "FAILURE STATE" */ if (dsr & DSR_VTD) dev_emerg(&imxdi->pdev->dev, "%sVoltage Tamper Event\n", dtcr & DTCR_VTE ? "" : "Spurious "); if (dsr & DSR_CTD) dev_emerg(&imxdi->pdev->dev, "%s32768 Hz Clock Tamper Event\n", dtcr & DTCR_CTE ? "" : "Spurious "); if (dsr & DSR_TTD) dev_emerg(&imxdi->pdev->dev, "%sTemperature Tamper Event\n", dtcr & DTCR_TTE ? "" : "Spurious "); if (dsr & DSR_SAD) dev_emerg(&imxdi->pdev->dev, "%sSecure Controller Alarm Event\n", dtcr & DTCR_SAIE ? "" : "Spurious "); if (dsr & DSR_EBD) dev_emerg(&imxdi->pdev->dev, "%sExternal Boot Tamper Event\n", dtcr & DTCR_EBE ? "" : "Spurious "); if (dsr & DSR_ETAD) dev_emerg(&imxdi->pdev->dev, "%sExternal Tamper A Event\n", dtcr & DTCR_ETAE ? "" : "Spurious "); if (dsr & DSR_ETBD) dev_emerg(&imxdi->pdev->dev, "%sExternal Tamper B Event\n", dtcr & DTCR_ETBE ? "" : "Spurious "); if (dsr & DSR_WTD) dev_emerg(&imxdi->pdev->dev, "%sWire-mesh Tamper Event\n", dtcr & DTCR_WTE ? "" : "Spurious "); if (dsr & DSR_MCO) dev_emerg(&imxdi->pdev->dev, "%sMonotonic-counter Overflow Event\n", dtcr & DTCR_MOE ? "" : "Spurious "); if (dsr & DSR_TCO) dev_emerg(&imxdi->pdev->dev, "%sTimer-counter Overflow Event\n", dtcr & DTCR_TOE ? "" : "Spurious "); } static void di_what_is_to_be_done(struct imxdi_dev *imxdi, const char *power_supply) { dev_emerg(&imxdi->pdev->dev, "Please cycle the %s power supply in order to get the DryIce/RTC unit working again\n", power_supply); } static int di_handle_failure_state(struct imxdi_dev *imxdi, u32 dsr) { u32 dcr; dev_dbg(&imxdi->pdev->dev, "DSR register reports: %08X\n", dsr); /* report the cause */ di_report_tamper_info(imxdi, dsr); dcr = readl(imxdi->ioaddr + DCR); if (dcr & DCR_FSHL) { /* we are out of luck */ di_what_is_to_be_done(imxdi, "battery"); return -ENODEV; } /* * with the next SYSTEM POR we will transit from the "FAILURE STATE" * into the "NON-VALID STATE" + "FAILURE STATE" */ di_what_is_to_be_done(imxdi, "main"); return -ENODEV; } static int di_handle_valid_state(struct imxdi_dev *imxdi, u32 dsr) { /* initialize alarm */ di_write_busy_wait(imxdi, DCAMR_UNSET, DCAMR); di_write_busy_wait(imxdi, 0, DCALR); /* clear alarm flag */ if (dsr & DSR_CAF) di_write_busy_wait(imxdi, DSR_CAF, DSR); return 0; } static int di_handle_invalid_state(struct imxdi_dev *imxdi, u32 dsr) { u32 dcr, sec; /* * lets disable all sources which can force the DryIce unit into * the "FAILURE STATE" for now */ di_write_busy_wait(imxdi, 0x00000000, DTCR); /* and lets protect them at runtime from any change */ di_write_busy_wait(imxdi, DCR_TDCSL, DCR); sec = readl(imxdi->ioaddr + DTCMR); if (sec != 0) dev_warn(&imxdi->pdev->dev, "The security violation has happened at %u seconds\n", sec); /* * the timer cannot be set/modified if * - the TCHL or TCSL bit is set in DCR */ dcr = readl(imxdi->ioaddr + DCR); if (!(dcr & DCR_TCE)) { if (dcr & DCR_TCHL) { /* we are out of luck */ di_what_is_to_be_done(imxdi, "battery"); return -ENODEV; } if (dcr & DCR_TCSL) { di_what_is_to_be_done(imxdi, "main"); return -ENODEV; } } /* * - the timer counter stops/is stopped if * - its overflow flag is set (TCO in DSR) * -> clear overflow bit to make it count again * - NVF is set in DSR * -> clear non-valid bit to make it count again * - its TCE (DCR) is cleared * -> set TCE to make it count * - it was never set before * -> write a time into it (required again if the NVF was set) */ /* state handled */ di_write_busy_wait(imxdi, DSR_NVF, DSR); /* clear overflow flag */ di_write_busy_wait(imxdi, DSR_TCO, DSR); /* enable the counter */ di_write_busy_wait(imxdi, dcr | DCR_TCE, DCR); /* set and trigger it to make it count */ di_write_busy_wait(imxdi, sec, DTCMR); /* now prepare for the valid state */ return di_handle_valid_state(imxdi, __raw_readl(imxdi->ioaddr + DSR)); } static int di_handle_invalid_and_failure_state(struct imxdi_dev *imxdi, u32 dsr) { u32 dcr; /* * now we must first remove the tamper sources in order to get the * device out of the "FAILURE STATE" * To disable any of the following sources we need to modify the DTCR */ if (dsr & (DSR_WTD | DSR_ETBD | DSR_ETAD | DSR_EBD | DSR_SAD | DSR_TTD | DSR_CTD | DSR_VTD | DSR_MCO | DSR_TCO)) { dcr = __raw_readl(imxdi->ioaddr + DCR); if (dcr & DCR_TDCHL) { /* * the tamper register is locked. We cannot disable the * tamper detection. The TDCHL can only be reset by a * DRYICE POR, but we cannot force a DRYICE POR in * softwere because we are still in "FAILURE STATE". * We need a DRYICE POR via battery power cycling.... */ /* * out of luck! * we cannot disable them without a DRYICE POR */ di_what_is_to_be_done(imxdi, "battery"); return -ENODEV; } if (dcr & DCR_TDCSL) { /* a soft lock can be removed by a SYSTEM POR */ di_what_is_to_be_done(imxdi, "main"); return -ENODEV; } } /* disable all sources */ di_write_busy_wait(imxdi, 0x00000000, DTCR); /* clear the status bits now */ di_write_busy_wait(imxdi, dsr & (DSR_WTD | DSR_ETBD | DSR_ETAD | DSR_EBD | DSR_SAD | DSR_TTD | DSR_CTD | DSR_VTD | DSR_MCO | DSR_TCO), DSR); dsr = readl(imxdi->ioaddr + DSR); if ((dsr & ~(DSR_NVF | DSR_SVF | DSR_WBF | DSR_WNF | DSR_WCF | DSR_WEF)) != 0) dev_warn(&imxdi->pdev->dev, "There are still some sources of pain in DSR: %08x!\n", dsr & ~(DSR_NVF | DSR_SVF | DSR_WBF | DSR_WNF | DSR_WCF | DSR_WEF)); /* * now we are trying to clear the "Security-violation flag" to * get the DryIce out of this state */ di_write_busy_wait(imxdi, DSR_SVF, DSR); /* success? */ dsr = readl(imxdi->ioaddr + DSR); if (dsr & DSR_SVF) { dev_crit(&imxdi->pdev->dev, "Cannot clear the security violation flag. We are ending up in an endless loop!\n"); /* last resort */ di_what_is_to_be_done(imxdi, "battery"); return -ENODEV; } /* * now we have left the "FAILURE STATE" and ending up in the * "NON-VALID STATE" time to recover everything */ return di_handle_invalid_state(imxdi, dsr); } static int di_handle_state(struct imxdi_dev *imxdi) { int rc; u32 dsr; dsr = readl(imxdi->ioaddr + DSR); switch (dsr & (DSR_NVF | DSR_SVF)) { case DSR_NVF: dev_warn(&imxdi->pdev->dev, "Invalid stated unit detected\n"); rc = di_handle_invalid_state(imxdi, dsr); break; case DSR_SVF: dev_warn(&imxdi->pdev->dev, "Failure stated unit detected\n"); rc = di_handle_failure_state(imxdi, dsr); break; case DSR_NVF | DSR_SVF: dev_warn(&imxdi->pdev->dev, "Failure+Invalid stated unit detected\n"); rc = di_handle_invalid_and_failure_state(imxdi, dsr); break; default: dev_notice(&imxdi->pdev->dev, "Unlocked unit detected\n"); rc = di_handle_valid_state(imxdi, dsr); } return rc; } /* * enable a dryice interrupt */ static void di_int_enable(struct imxdi_dev *imxdi, u32 intr) { unsigned long flags; spin_lock_irqsave(&imxdi->irq_lock, flags); writel(readl(imxdi->ioaddr + DIER) | intr, imxdi->ioaddr + DIER); spin_unlock_irqrestore(&imxdi->irq_lock, flags); } /* * disable a dryice interrupt */ static void di_int_disable(struct imxdi_dev *imxdi, u32 intr) { unsigned long flags; spin_lock_irqsave(&imxdi->irq_lock, flags); writel(readl(imxdi->ioaddr + DIER) & ~intr, imxdi->ioaddr + DIER); spin_unlock_irqrestore(&imxdi->irq_lock, flags); } /* * This function attempts to clear the dryice write-error flag. * * A dryice write error is similar to a bus fault and should not occur in * normal operation. Clearing the flag requires another write, so the root * cause of the problem may need to be fixed before the flag can be cleared. */ static void clear_write_error(struct imxdi_dev *imxdi) { int cnt; dev_warn(&imxdi->pdev->dev, "WARNING: Register write error!\n"); /* clear the write error flag */ writel(DSR_WEF, imxdi->ioaddr + DSR); /* wait for it to take effect */ for (cnt = 0; cnt < 1000; cnt++) { if ((readl(imxdi->ioaddr + DSR) & DSR_WEF) == 0) return; udelay(10); } dev_err(&imxdi->pdev->dev, "ERROR: Cannot clear write-error flag!\n"); } /* * Write a dryice register and wait until it completes. * * This function uses interrupts to determine when the * write has completed. */ static int di_write_wait(struct imxdi_dev *imxdi, u32 val, int reg) { int ret; int rc = 0; /* serialize register writes */ mutex_lock(&imxdi->write_mutex); /* enable the write-complete interrupt */ di_int_enable(imxdi, DIER_WCIE); imxdi->dsr = 0; /* do the register write */ writel(val, imxdi->ioaddr + reg); /* wait for the write to finish */ ret = wait_event_interruptible_timeout(imxdi->write_wait, imxdi->dsr & (DSR_WCF | DSR_WEF), msecs_to_jiffies(1)); if (ret < 0) { rc = ret; goto out; } else if (ret == 0) { dev_warn(&imxdi->pdev->dev, "Write-wait timeout " "val = 0x%08x reg = 0x%08x\n", val, reg); } /* check for write error */ if (imxdi->dsr & DSR_WEF) { clear_write_error(imxdi); rc = -EIO; } out: mutex_unlock(&imxdi->write_mutex); return rc; } /* * read the seconds portion of the current time from the dryice time counter */ static int dryice_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct imxdi_dev *imxdi = dev_get_drvdata(dev); unsigned long now; now = readl(imxdi->ioaddr + DTCMR); rtc_time_to_tm(now, tm); return 0; } /* * set the seconds portion of dryice time counter and clear the * fractional part. */ static int dryice_rtc_set_mmss(struct device *dev, unsigned long secs) { struct imxdi_dev *imxdi = dev_get_drvdata(dev); u32 dcr, dsr; int rc; dcr = readl(imxdi->ioaddr + DCR); dsr = readl(imxdi->ioaddr + DSR); if (!(dcr & DCR_TCE) || (dsr & DSR_SVF)) { if (dcr & DCR_TCHL) { /* we are even more out of luck */ di_what_is_to_be_done(imxdi, "battery"); return -EPERM; } if ((dcr & DCR_TCSL) || (dsr & DSR_SVF)) { /* we are out of luck for now */ di_what_is_to_be_done(imxdi, "main"); return -EPERM; } } /* zero the fractional part first */ rc = di_write_wait(imxdi, 0, DTCLR); if (rc != 0) return rc; rc = di_write_wait(imxdi, secs, DTCMR); if (rc != 0) return rc; return di_write_wait(imxdi, readl(imxdi->ioaddr + DCR) | DCR_TCE, DCR); } static int dryice_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct imxdi_dev *imxdi = dev_get_drvdata(dev); if (enabled) di_int_enable(imxdi, DIER_CAIE); else di_int_disable(imxdi, DIER_CAIE); return 0; } /* * read the seconds portion of the alarm register. * the fractional part of the alarm register is always zero. */ static int dryice_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) { struct imxdi_dev *imxdi = dev_get_drvdata(dev); u32 dcamr; dcamr = readl(imxdi->ioaddr + DCAMR); rtc_time_to_tm(dcamr, &alarm->time); /* alarm is enabled if the interrupt is enabled */ alarm->enabled = (readl(imxdi->ioaddr + DIER) & DIER_CAIE) != 0; /* don't allow the DSR read to mess up DSR_WCF */ mutex_lock(&imxdi->write_mutex); /* alarm is pending if the alarm flag is set */ alarm->pending = (readl(imxdi->ioaddr + DSR) & DSR_CAF) != 0; mutex_unlock(&imxdi->write_mutex); return 0; } /* * set the seconds portion of dryice alarm register */ static int dryice_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) { struct imxdi_dev *imxdi = dev_get_drvdata(dev); unsigned long now; unsigned long alarm_time; int rc; rc = rtc_tm_to_time(&alarm->time, &alarm_time); if (rc) return rc; /* don't allow setting alarm in the past */ now = readl(imxdi->ioaddr + DTCMR); if (alarm_time < now) return -EINVAL; /* write the new alarm time */ rc = di_write_wait(imxdi, (u32)alarm_time, DCAMR); if (rc) return rc; if (alarm->enabled) di_int_enable(imxdi, DIER_CAIE); /* enable alarm intr */ else di_int_disable(imxdi, DIER_CAIE); /* disable alarm intr */ return 0; } static const struct rtc_class_ops dryice_rtc_ops = { .read_time = dryice_rtc_read_time, .set_mmss = dryice_rtc_set_mmss, .alarm_irq_enable = dryice_rtc_alarm_irq_enable, .read_alarm = dryice_rtc_read_alarm, .set_alarm = dryice_rtc_set_alarm, }; /* * interrupt handler for dryice "normal" and security violation interrupt */ static irqreturn_t dryice_irq(int irq, void *dev_id) { struct imxdi_dev *imxdi = dev_id; u32 dsr, dier; irqreturn_t rc = IRQ_NONE; dier = readl(imxdi->ioaddr + DIER); dsr = readl(imxdi->ioaddr + DSR); /* handle the security violation event */ if (dier & DIER_SVIE) { if (dsr & DSR_SVF) { /* * Disable the interrupt when this kind of event has * happened. * There cannot be more than one event of this type, * because it needs a complex state change * including a main power cycle to get again out of * this state. */ di_int_disable(imxdi, DIER_SVIE); /* report the violation */ di_report_tamper_info(imxdi, dsr); rc = IRQ_HANDLED; } } /* handle write complete and write error cases */ if (dier & DIER_WCIE) { /*If the write wait queue is empty then there is no pending operations. It means the interrupt is for DryIce -Security. IRQ must be returned as none.*/ if (list_empty_careful(&imxdi->write_wait.head)) return rc; /* DSR_WCF clears itself on DSR read */ if (dsr & (DSR_WCF | DSR_WEF)) { /* mask the interrupt */ di_int_disable(imxdi, DIER_WCIE); /* save the dsr value for the wait queue */ imxdi->dsr |= dsr; wake_up_interruptible(&imxdi->write_wait); rc = IRQ_HANDLED; } } /* handle the alarm case */ if (dier & DIER_CAIE) { /* DSR_WCF clears itself on DSR read */ if (dsr & DSR_CAF) { /* mask the interrupt */ di_int_disable(imxdi, DIER_CAIE); /* finish alarm in user context */ schedule_work(&imxdi->work); rc = IRQ_HANDLED; } } return rc; } /* * post the alarm event from user context so it can sleep * on the write completion. */ static void dryice_work(struct work_struct *work) { struct imxdi_dev *imxdi = container_of(work, struct imxdi_dev, work); /* dismiss the interrupt (ignore error) */ di_write_wait(imxdi, DSR_CAF, DSR); /* pass the alarm event to the rtc framework. */ rtc_update_irq(imxdi->rtc, 1, RTC_AF | RTC_IRQF); } /* * probe for dryice rtc device */ static int __init dryice_rtc_probe(struct platform_device *pdev) { struct resource *res; struct imxdi_dev *imxdi; int norm_irq, sec_irq; int rc; imxdi = devm_kzalloc(&pdev->dev, sizeof(*imxdi), GFP_KERNEL); if (!imxdi) return -ENOMEM; imxdi->pdev = pdev; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); imxdi->ioaddr = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(imxdi->ioaddr)) return PTR_ERR(imxdi->ioaddr); spin_lock_init(&imxdi->irq_lock); norm_irq = platform_get_irq(pdev, 0); if (norm_irq < 0) return norm_irq; /* the 2nd irq is the security violation irq * make this optional, don't break the device tree ABI */ sec_irq = platform_get_irq(pdev, 1); if (sec_irq <= 0) sec_irq = IRQ_NOTCONNECTED; init_waitqueue_head(&imxdi->write_wait); INIT_WORK(&imxdi->work, dryice_work); mutex_init(&imxdi->write_mutex); imxdi->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(imxdi->clk)) return PTR_ERR(imxdi->clk); rc = clk_prepare_enable(imxdi->clk); if (rc) return rc; /* * Initialize dryice hardware */ /* mask all interrupts */ writel(0, imxdi->ioaddr + DIER); rc = di_handle_state(imxdi); if (rc != 0) goto err; rc = devm_request_irq(&pdev->dev, norm_irq, dryice_irq, IRQF_SHARED, pdev->name, imxdi); if (rc) { dev_warn(&pdev->dev, "interrupt not available.\n"); goto err; } rc = devm_request_irq(&pdev->dev, sec_irq, dryice_irq, IRQF_SHARED, pdev->name, imxdi); if (rc) { dev_warn(&pdev->dev, "security violation interrupt not available.\n"); /* this is not an error, see above */ } platform_set_drvdata(pdev, imxdi); imxdi->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &dryice_rtc_ops, THIS_MODULE); if (IS_ERR(imxdi->rtc)) { rc = PTR_ERR(imxdi->rtc); goto err; } return 0; err: clk_disable_unprepare(imxdi->clk); return rc; } static int __exit dryice_rtc_remove(struct platform_device *pdev) { struct imxdi_dev *imxdi = platform_get_drvdata(pdev); flush_work(&imxdi->work); /* mask all interrupts */ writel(0, imxdi->ioaddr + DIER); clk_disable_unprepare(imxdi->clk); return 0; } #ifdef CONFIG_OF static const struct of_device_id dryice_dt_ids[] = { { .compatible = "fsl,imx25-rtc" }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, dryice_dt_ids); #endif static struct platform_driver dryice_rtc_driver = { .driver = { .name = "imxdi_rtc", .of_match_table = of_match_ptr(dryice_dt_ids), }, .remove = __exit_p(dryice_rtc_remove), }; module_platform_driver_probe(dryice_rtc_driver, dryice_rtc_probe); MODULE_AUTHOR("Freescale Semiconductor, Inc."); MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); MODULE_DESCRIPTION("IMX DryIce Realtime Clock Driver (RTC)"); MODULE_LICENSE("GPL");
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