From 558c61e5579a81551c0d6c2deaed1da3c7bf714a Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 12 Jun 2013 14:04:52 -0700 Subject: rtc-at91rm9200: add match-table compile guard The members of Atmel's at91sam9x5 family (9x5) have a broken RTC interrupt mask register (AT91_RTC_IMR). It does not reflect enabled interrupts but instead always returns zero. The kernel's rtc-at91rm9200 driver handles the RTC for the 9x5 family. Currently when the date/time is set, an interrupt is generated and this driver neglects to handle the interrupt. The kernel complains about the un-handled interrupt and disables it henceforth. This not only breaks the RTC function, but since that interrupt is shared (Atmel's SYS interrupt) then other things break as well (e.g. the debug port no longer accepts characters). Tested on the at91sam9g25. Bug confirmed by Atmel. This patch (of 5): Add missing match-table compile guard. Signed-off-by: Johan Hovold Acked-by: Nicolas Ferre Cc: Douglas Gilbert Cc: Jean-Christophe PLAGNIOL-VILLARD Cc: Ludovic Desroches Cc: Robert Nelson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-at91rm9200.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/rtc/rtc-at91rm9200.c') diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c index 0eab77b22340..eeeb73f1fc3b 100644 --- a/drivers/rtc/rtc-at91rm9200.c +++ b/drivers/rtc/rtc-at91rm9200.c @@ -383,11 +383,13 @@ static int at91_rtc_resume(struct device *dev) static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume); +#ifdef CONFIG_OF static const struct of_device_id at91_rtc_dt_ids[] = { { .compatible = "atmel,at91rm9200-rtc" }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids); +#endif static struct platform_driver at91_rtc_driver = { .remove = __exit_p(at91_rtc_remove), -- cgit v1.2.3 From de645475913f677eb024b3d2bd52e264e8106497 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 12 Jun 2013 14:04:53 -0700 Subject: rtc-at91rm9200: add configuration support Add configuration support which can be used to implement SoC-specific workarounds for broken hardware. Signed-off-by: Johan Hovold Acked-by: Nicolas Ferre Cc: Douglas Gilbert Cc: Jean-Christophe PLAGNIOL-VILLARD Cc: Ludovic Desroches Cc: Robert Nelson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-at91rm9200.c | 46 ++++++++++++++++++++++++++++++++++++-------- 1 file changed, 38 insertions(+), 8 deletions(-) (limited to 'drivers/rtc/rtc-at91rm9200.c') diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c index eeeb73f1fc3b..ab2024b159fa 100644 --- a/drivers/rtc/rtc-at91rm9200.c +++ b/drivers/rtc/rtc-at91rm9200.c @@ -42,6 +42,10 @@ #define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */ +struct at91_rtc_config { +}; + +static const struct at91_rtc_config *at91_rtc_config; static DECLARE_COMPLETION(at91_rtc_updated); static unsigned int at91_alarm_year = AT91_RTC_EPOCH; static void __iomem *at91_rtc_regs; @@ -250,6 +254,36 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id) return IRQ_NONE; /* not handled */ } +static const struct at91_rtc_config at91rm9200_config = { +}; + +#ifdef CONFIG_OF +static const struct of_device_id at91_rtc_dt_ids[] = { + { + .compatible = "atmel,at91rm9200-rtc", + .data = &at91rm9200_config, + }, { + /* sentinel */ + } +}; +MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids); +#endif + +static const struct at91_rtc_config * +at91_rtc_get_config(struct platform_device *pdev) +{ + const struct of_device_id *match; + + if (pdev->dev.of_node) { + match = of_match_node(at91_rtc_dt_ids, pdev->dev.of_node); + if (!match) + return NULL; + return (const struct at91_rtc_config *)match->data; + } + + return &at91rm9200_config; +} + static const struct rtc_class_ops at91_rtc_ops = { .read_time = at91_rtc_readtime, .set_time = at91_rtc_settime, @@ -268,6 +302,10 @@ static int __init at91_rtc_probe(struct platform_device *pdev) struct resource *regs; int ret = 0; + at91_rtc_config = at91_rtc_get_config(pdev); + if (!at91_rtc_config) + return -ENODEV; + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!regs) { dev_err(&pdev->dev, "no mmio resource defined\n"); @@ -383,14 +421,6 @@ static int at91_rtc_resume(struct device *dev) static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume); -#ifdef CONFIG_OF -static const struct of_device_id at91_rtc_dt_ids[] = { - { .compatible = "atmel,at91rm9200-rtc" }, - { /* sentinel */ } -}; -MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids); -#endif - static struct platform_driver at91_rtc_driver = { .remove = __exit_p(at91_rtc_remove), .driver = { -- cgit v1.2.3 From e304fcd075a0e97d0e538dd4408b95406b505f85 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 12 Jun 2013 14:04:55 -0700 Subject: rtc-at91rm9200: refactor interrupt-register handling Add accessors for the interrupt register. This will allow us to easily add a shadow interrupt-mask register to use on SoCs where the interrupt-mask register cannot be used. Signed-off-by: Johan Hovold Acked-by: Nicolas Ferre Cc: Douglas Gilbert Cc: Jean-Christophe PLAGNIOL-VILLARD Cc: Ludovic Desroches Cc: Robert Nelson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-at91rm9200.c | 43 +++++++++++++++++++++++++++++-------------- 1 file changed, 29 insertions(+), 14 deletions(-) (limited to 'drivers/rtc/rtc-at91rm9200.c') diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c index ab2024b159fa..9592d08f3b11 100644 --- a/drivers/rtc/rtc-at91rm9200.c +++ b/drivers/rtc/rtc-at91rm9200.c @@ -51,6 +51,21 @@ static unsigned int at91_alarm_year = AT91_RTC_EPOCH; static void __iomem *at91_rtc_regs; static int irq; +static void at91_rtc_write_ier(u32 mask) +{ + at91_rtc_write(AT91_RTC_IER, mask); +} + +static void at91_rtc_write_idr(u32 mask) +{ + at91_rtc_write(AT91_RTC_IDR, mask); +} + +static u32 at91_rtc_read_imr(void) +{ + return at91_rtc_read(AT91_RTC_IMR); +} + /* * Decode time/date into rtc_time structure */ @@ -114,9 +129,9 @@ static int at91_rtc_settime(struct device *dev, struct rtc_time *tm) cr = at91_rtc_read(AT91_RTC_CR); at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM); - at91_rtc_write(AT91_RTC_IER, AT91_RTC_ACKUPD); + at91_rtc_write_ier(AT91_RTC_ACKUPD); wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */ - at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD); + at91_rtc_write_idr(AT91_RTC_ACKUPD); at91_rtc_write(AT91_RTC_TIMR, bin2bcd(tm->tm_sec) << 0 @@ -148,7 +163,7 @@ static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); tm->tm_year = at91_alarm_year - 1900; - alrm->enabled = (at91_rtc_read(AT91_RTC_IMR) & AT91_RTC_ALARM) + alrm->enabled = (at91_rtc_read_imr() & AT91_RTC_ALARM) ? 1 : 0; dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, @@ -173,7 +188,7 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) tm.tm_min = alrm->time.tm_min; tm.tm_sec = alrm->time.tm_sec; - at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM); + at91_rtc_write_idr(AT91_RTC_ALARM); at91_rtc_write(AT91_RTC_TIMALR, bin2bcd(tm.tm_sec) << 0 | bin2bcd(tm.tm_min) << 8 @@ -186,7 +201,7 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) if (alrm->enabled) { at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM); - at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM); + at91_rtc_write_ier(AT91_RTC_ALARM); } dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, @@ -202,9 +217,9 @@ static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) if (enabled) { at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM); - at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM); + at91_rtc_write_ier(AT91_RTC_ALARM); } else - at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM); + at91_rtc_write_idr(AT91_RTC_ALARM); return 0; } @@ -213,7 +228,7 @@ static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) */ static int at91_rtc_proc(struct device *dev, struct seq_file *seq) { - unsigned long imr = at91_rtc_read(AT91_RTC_IMR); + unsigned long imr = at91_rtc_read_imr(); seq_printf(seq, "update_IRQ\t: %s\n", (imr & AT91_RTC_ACKUPD) ? "yes" : "no"); @@ -233,7 +248,7 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id) unsigned int rtsr; unsigned long events = 0; - rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read(AT91_RTC_IMR); + rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read_imr(); if (rtsr) { /* this interrupt is shared! Is it ours? */ if (rtsr & AT91_RTC_ALARM) events |= (RTC_AF | RTC_IRQF); @@ -328,7 +343,7 @@ static int __init at91_rtc_probe(struct platform_device *pdev) at91_rtc_write(AT91_RTC_MR, 0); /* 24 hour mode */ /* Disable all interrupts */ - at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | + at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM | AT91_RTC_SECEV | AT91_RTC_TIMEV | AT91_RTC_CALEV); @@ -373,7 +388,7 @@ static int __exit at91_rtc_remove(struct platform_device *pdev) struct rtc_device *rtc = platform_get_drvdata(pdev); /* Disable all interrupts */ - at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | + at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM | AT91_RTC_SECEV | AT91_RTC_TIMEV | AT91_RTC_CALEV); free_irq(irq, pdev); @@ -396,13 +411,13 @@ static int at91_rtc_suspend(struct device *dev) /* this IRQ is shared with DBGU and other hardware which isn't * necessarily doing PM like we are... */ - at91_rtc_imr = at91_rtc_read(AT91_RTC_IMR) + at91_rtc_imr = at91_rtc_read_imr() & (AT91_RTC_ALARM|AT91_RTC_SECEV); if (at91_rtc_imr) { if (device_may_wakeup(dev)) enable_irq_wake(irq); else - at91_rtc_write(AT91_RTC_IDR, at91_rtc_imr); + at91_rtc_write_idr(at91_rtc_imr); } return 0; } @@ -413,7 +428,7 @@ static int at91_rtc_resume(struct device *dev) if (device_may_wakeup(dev)) disable_irq_wake(irq); else - at91_rtc_write(AT91_RTC_IER, at91_rtc_imr); + at91_rtc_write_ier(at91_rtc_imr); } return 0; } -- cgit v1.2.3 From e9f08bbe3f97829975d2b59091ef557101c83f61 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 12 Jun 2013 14:04:56 -0700 Subject: rtc-at91rm9200: add shadow interrupt mask Add shadow interrupt-mask register which can be used on SoCs where the actual hardware register is broken. Note that some care needs to be taken to make sure the shadow mask corresponds to the actual hardware state. The added overhead is not an issue for the non-broken SoCs due to the relatively infrequent interrupt-mask updates. We do, however, only use the shadow mask value as a fall-back when it actually needed as there is still a theoretical possibility that the mask is incorrect (see the code for details). Signed-off-by: Johan Hovold Acked-by: Nicolas Ferre Cc: Douglas Gilbert Cc: Jean-Christophe PLAGNIOL-VILLARD Cc: Ludovic Desroches Cc: Robert Nelson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-at91rm9200.c | 39 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 38 insertions(+), 1 deletion(-) (limited to 'drivers/rtc/rtc-at91rm9200.c') diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c index 9592d08f3b11..811a102092d4 100644 --- a/drivers/rtc/rtc-at91rm9200.c +++ b/drivers/rtc/rtc-at91rm9200.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include #include @@ -43,6 +44,7 @@ #define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */ struct at91_rtc_config { + bool use_shadow_imr; }; static const struct at91_rtc_config *at91_rtc_config; @@ -50,20 +52,55 @@ static DECLARE_COMPLETION(at91_rtc_updated); static unsigned int at91_alarm_year = AT91_RTC_EPOCH; static void __iomem *at91_rtc_regs; static int irq; +static DEFINE_SPINLOCK(at91_rtc_lock); +static u32 at91_rtc_shadow_imr; static void at91_rtc_write_ier(u32 mask) { + unsigned long flags; + + spin_lock_irqsave(&at91_rtc_lock, flags); + at91_rtc_shadow_imr |= mask; at91_rtc_write(AT91_RTC_IER, mask); + spin_unlock_irqrestore(&at91_rtc_lock, flags); } static void at91_rtc_write_idr(u32 mask) { + unsigned long flags; + + spin_lock_irqsave(&at91_rtc_lock, flags); at91_rtc_write(AT91_RTC_IDR, mask); + /* + * Register read back (of any RTC-register) needed to make sure + * IDR-register write has reached the peripheral before updating + * shadow mask. + * + * Note that there is still a possibility that the mask is updated + * before interrupts have actually been disabled in hardware. The only + * way to be certain would be to poll the IMR-register, which is is + * the very register we are trying to emulate. The register read back + * is a reasonable heuristic. + */ + at91_rtc_read(AT91_RTC_SR); + at91_rtc_shadow_imr &= ~mask; + spin_unlock_irqrestore(&at91_rtc_lock, flags); } static u32 at91_rtc_read_imr(void) { - return at91_rtc_read(AT91_RTC_IMR); + unsigned long flags; + u32 mask; + + if (at91_rtc_config->use_shadow_imr) { + spin_lock_irqsave(&at91_rtc_lock, flags); + mask = at91_rtc_shadow_imr; + spin_unlock_irqrestore(&at91_rtc_lock, flags); + } else { + mask = at91_rtc_read(AT91_RTC_IMR); + } + + return mask; } /* -- cgit v1.2.3 From bba00e59107275faa615573c44eb0a513a1220a6 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 12 Jun 2013 14:04:57 -0700 Subject: rtc-at91rm9200: use shadow IMR on at91sam9x5 Add support for the at91sam9x5-family which must use the shadow interrupt mask due to a hardware issue (causing RTC_IMR to always be zero). Signed-off-by: Johan Hovold Acked-by: Nicolas Ferre Cc: Douglas Gilbert Cc: Jean-Christophe PLAGNIOL-VILLARD Cc: Ludovic Desroches Cc: Robert Nelson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/devicetree/bindings/rtc/atmel,at91rm9200-rtc.txt | 2 +- drivers/rtc/rtc-at91rm9200.c | 7 +++++++ 2 files changed, 8 insertions(+), 1 deletion(-) (limited to 'drivers/rtc/rtc-at91rm9200.c') diff --git a/Documentation/devicetree/bindings/rtc/atmel,at91rm9200-rtc.txt b/Documentation/devicetree/bindings/rtc/atmel,at91rm9200-rtc.txt index 2a3feabd3b22..34c1505774bf 100644 --- a/Documentation/devicetree/bindings/rtc/atmel,at91rm9200-rtc.txt +++ b/Documentation/devicetree/bindings/rtc/atmel,at91rm9200-rtc.txt @@ -1,7 +1,7 @@ Atmel AT91RM9200 Real Time Clock Required properties: -- compatible: should be: "atmel,at91rm9200-rtc" +- compatible: should be: "atmel,at91rm9200-rtc" or "atmel,at91sam9x5-rtc" - reg: physical base address of the controller and length of memory mapped region. - interrupts: rtc alarm/event interrupt diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c index 811a102092d4..f296f3f7db9b 100644 --- a/drivers/rtc/rtc-at91rm9200.c +++ b/drivers/rtc/rtc-at91rm9200.c @@ -309,11 +309,18 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id) static const struct at91_rtc_config at91rm9200_config = { }; +static const struct at91_rtc_config at91sam9x5_config = { + .use_shadow_imr = true, +}; + #ifdef CONFIG_OF static const struct of_device_id at91_rtc_dt_ids[] = { { .compatible = "atmel,at91rm9200-rtc", .data = &at91rm9200_config, + }, { + .compatible = "atmel,at91sam9x5-rtc", + .data = &at91sam9x5_config, }, { /* sentinel */ } -- cgit v1.2.3