| Message ID | alpine.DEB.2.00.1006131208470.18415@ayla.of.borg |
|---|---|
| State | Accepted |
| Headers | show |
Hi Geert , Minior comment below: 2010/6/13 Geert Uytterhoeven <geert@linux-m68k.org>: > The Ricoh RP5C01 RTC contains 26 x 4 bits of NVRAM. > Provide access to it via a sysfs "nvram" attribute file. > > Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> > -- > Question: Is a spinlock in priv the right kind of locking? > Should I use e.g. rtc-device.ops_lock instead? Firstly, this 'Question' text should not put here, please put all texts in front of '---'. Secondly, You can not use rtc-device.ops_lock here, if so, it would arouse dead lock, before the ' rp5c01_read_time()' was called by RTC subsystem upper API, rtc-device.ops_lock has been required sucessfully, If continue to require the rtc-device.ops_lock in ' rp5c01_read_time()', the 'lock' will cannot be get, dead lock occurs. > > diff --git a/drivers/rtc/rtc-rp5c01.c b/drivers/rtc/rtc-rp5c01.c > index a95f733..36eb661 100644 > --- a/drivers/rtc/rtc-rp5c01.c > +++ b/drivers/rtc/rtc-rp5c01.c > @@ -63,6 +63,8 @@ enum { > struct rp5c01_priv { > u32 __iomem *regs; > struct rtc_device *rtc; > + spinlock_t lock; /* against concurrent RTC/NVRAM access */ > + struct bin_attribute nvram_attr; > }; > > static inline unsigned int rp5c01_read(struct rp5c01_priv *priv, > @@ -92,6 +94,7 @@ static int rp5c01_read_time(struct device *dev, struct rtc_time *tm) > { > struct rp5c01_priv *priv = dev_get_drvdata(dev); > > + spin_lock_irq(&priv->lock); > rp5c01_lock(priv); > > tm->tm_sec = rp5c01_read(priv, RP5C01_10_SECOND) * 10 + > @@ -111,6 +114,7 @@ static int rp5c01_read_time(struct device *dev, struct rtc_time *tm) > tm->tm_year += 100; > > rp5c01_unlock(priv); > + spin_unlock_irq(&priv->lock); > > return rtc_valid_tm(tm); > } > @@ -119,6 +123,7 @@ static int rp5c01_set_time(struct device *dev, struct rtc_time *tm) > { > struct rp5c01_priv *priv = dev_get_drvdata(dev); > > + spin_lock_irq(&priv->lock); > rp5c01_lock(priv); > > rp5c01_write(priv, tm->tm_sec / 10, RP5C01_10_SECOND); > @@ -139,6 +144,7 @@ static int rp5c01_set_time(struct device *dev, struct rtc_time *tm) > rp5c01_write(priv, tm->tm_year % 10, RP5C01_1_YEAR); > > rp5c01_unlock(priv); > + spin_unlock_irq(&priv->lock); > return 0; > } > > @@ -147,6 +153,72 @@ static const struct rtc_class_ops rp5c01_rtc_ops = { > .set_time = rp5c01_set_time, > }; > > + > +/* > + * The NVRAM is organized as 2 blocks of 13 nibbles of 4 bits. > + * We provide access to them like AmigaOS does: the high nibble of each 8-bit > + * byte is stored in BLOCK10, the low nibble in BLOCK11. > + */ > + > +static ssize_t rp5c01_nvram_read(struct file *filp, struct kobject *kobj, > + struct bin_attribute *bin_attr, > + char *buf, loff_t pos, size_t size) > +{ > + struct device *dev = container_of(kobj, struct device, kobj); > + struct rp5c01_priv *priv = dev_get_drvdata(dev); > + ssize_t count; > + > + spin_lock_irq(&priv->lock); > + > + for (count = 0; size > 0 && pos < RP5C01_MODE; count++, size--) { > + u8 data; > + > + rp5c01_write(priv, > + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK10, > + RP5C01_MODE); > + data = rp5c01_read(priv, pos) << 4; > + rp5c01_write(priv, > + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK11, > + RP5C01_MODE); > + data |= rp5c01_read(priv, pos++); > + rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01, > + RP5C01_MODE); > + *buf++ = data; > + } > + > + spin_unlock_irq(&priv->lock); > + return count; > +} > + > +static ssize_t rp5c01_nvram_write(struct file *filp, struct kobject *kobj, > + struct bin_attribute *bin_attr, > + char *buf, loff_t pos, size_t size) > +{ > + struct device *dev = container_of(kobj, struct device, kobj); > + struct rp5c01_priv *priv = dev_get_drvdata(dev); > + ssize_t count; > + > + spin_lock_irq(&priv->lock); > + > + for (count = 0; size > 0 && pos < RP5C01_MODE; count++, size--) { > + u8 data = *buf++; > + > + rp5c01_write(priv, > + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK10, > + RP5C01_MODE); > + rp5c01_write(priv, data >> 4, pos); > + rp5c01_write(priv, > + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK11, > + RP5C01_MODE); > + rp5c01_write(priv, data & 0xf, pos++); > + rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01, > + RP5C01_MODE); > + } > + > + spin_unlock_irq(&priv->lock); > + return count; > +} > + > static int __init rp5c01_rtc_probe(struct platform_device *dev) > { > struct resource *res; > @@ -168,6 +240,15 @@ static int __init rp5c01_rtc_probe(struct platform_device *dev) > goto out_free_priv; > } > > + sysfs_bin_attr_init(&priv->nvram_attr); > + priv->nvram_attr.attr.name = "nvram"; > + priv->nvram_attr.attr.mode = S_IRUGO | S_IWUSR; > + priv->nvram_attr.read = rp5c01_nvram_read; > + priv->nvram_attr.write = rp5c01_nvram_write; > + priv->nvram_attr.size = RP5C01_MODE; > + > + spin_lock_init(&priv->lock); > + > rtc = rtc_device_register("rtc-rp5c01", &dev->dev, &rp5c01_rtc_ops, > THIS_MODULE); > if (IS_ERR(rtc)) { > @@ -177,8 +258,15 @@ static int __init rp5c01_rtc_probe(struct platform_device *dev) > > priv->rtc = rtc; > platform_set_drvdata(dev, priv); > + > + error = sysfs_create_bin_file(&dev->dev.kobj, &priv->nvram_attr); > + if (error) > + goto out_unregister; > + > return 0; > > +out_unregister: > + rtc_device_unregister(rtc); > out_unmap: > iounmap(priv->regs); > out_free_priv: > @@ -190,6 +278,7 @@ static int __exit rp5c01_rtc_remove(struct platform_device *dev) > { > struct rp5c01_priv *priv = platform_get_drvdata(dev); > > + sysfs_remove_bin_file(&dev->dev.kobj, &priv->nvram_attr); > rtc_device_unregister(priv->rtc); > iounmap(priv->regs); > kfree(priv); > -- > 1.7.0.4 > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds > > -- > You received this message because you are subscribed to "rtc-linux". > Membership options at http://groups.google.com/group/rtc-linux . > Please read http://groups.google.com/group/rtc-linux/web/checklist > before submitting a driver.
On Sun, Jun 13, 2010 at 15:41, Wan ZongShun <mcuos.com@gmail.com> wrote: > Minior comment below: > > 2010/6/13 Geert Uytterhoeven <geert@linux-m68k.org>: >> The Ricoh RP5C01 RTC contains 26 x 4 bits of NVRAM. >> Provide access to it via a sysfs "nvram" attribute file. >> >> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> >> -- >> Question: Is a spinlock in priv the right kind of locking? >> Should I use e.g. rtc-device.ops_lock instead? > > Firstly, this 'Question' text should not put here, please put all > texts in front of '---'. I explicitly put it there, as the question was meant for the reviewers only, and I don't want it to be part of the final checkin comment. > Secondly, You can not use rtc-device.ops_lock here, if so, it would > arouse dead lock, > before the ' rp5c01_read_time()' was called by RTC subsystem upper > API, rtc-device.ops_lock > has been required sucessfully, If continue to require the > rtc-device.ops_lock in ' rp5c01_read_time()', > the 'lock' will cannot be get, dead lock occurs. Sorry, my question was not that correctly formulated... I meant whether it's better to take rtc_device.ops_lock in the nvram access functions to synchronize with the RTC access functions (which already take that mutex), instead of adding a spinlock to priv. Thanks for your comments! >> diff --git a/drivers/rtc/rtc-rp5c01.c b/drivers/rtc/rtc-rp5c01.c >> index a95f733..36eb661 100644 >> --- a/drivers/rtc/rtc-rp5c01.c >> +++ b/drivers/rtc/rtc-rp5c01.c >> @@ -63,6 +63,8 @@ enum { >> struct rp5c01_priv { >> u32 __iomem *regs; >> struct rtc_device *rtc; >> + spinlock_t lock; /* against concurrent RTC/NVRAM access */ >> + struct bin_attribute nvram_attr; >> }; >> >> static inline unsigned int rp5c01_read(struct rp5c01_priv *priv, >> @@ -92,6 +94,7 @@ static int rp5c01_read_time(struct device *dev, struct rtc_time *tm) >> { >> struct rp5c01_priv *priv = dev_get_drvdata(dev); >> >> + spin_lock_irq(&priv->lock); >> rp5c01_lock(priv); >> >> tm->tm_sec = rp5c01_read(priv, RP5C01_10_SECOND) * 10 + >> @@ -111,6 +114,7 @@ static int rp5c01_read_time(struct device *dev, struct rtc_time *tm) >> tm->tm_year += 100; >> >> rp5c01_unlock(priv); >> + spin_unlock_irq(&priv->lock); >> >> return rtc_valid_tm(tm); >> } >> @@ -119,6 +123,7 @@ static int rp5c01_set_time(struct device *dev, struct rtc_time *tm) >> { >> struct rp5c01_priv *priv = dev_get_drvdata(dev); >> >> + spin_lock_irq(&priv->lock); >> rp5c01_lock(priv); >> >> rp5c01_write(priv, tm->tm_sec / 10, RP5C01_10_SECOND); >> @@ -139,6 +144,7 @@ static int rp5c01_set_time(struct device *dev, struct rtc_time *tm) >> rp5c01_write(priv, tm->tm_year % 10, RP5C01_1_YEAR); >> >> rp5c01_unlock(priv); >> + spin_unlock_irq(&priv->lock); >> return 0; >> } >> >> @@ -147,6 +153,72 @@ static const struct rtc_class_ops rp5c01_rtc_ops = { >> .set_time = rp5c01_set_time, >> }; >> >> + >> +/* >> + * The NVRAM is organized as 2 blocks of 13 nibbles of 4 bits. >> + * We provide access to them like AmigaOS does: the high nibble of each 8-bit >> + * byte is stored in BLOCK10, the low nibble in BLOCK11. >> + */ >> + >> +static ssize_t rp5c01_nvram_read(struct file *filp, struct kobject *kobj, >> + struct bin_attribute *bin_attr, >> + char *buf, loff_t pos, size_t size) >> +{ >> + struct device *dev = container_of(kobj, struct device, kobj); >> + struct rp5c01_priv *priv = dev_get_drvdata(dev); >> + ssize_t count; >> + >> + spin_lock_irq(&priv->lock); >> + >> + for (count = 0; size > 0 && pos < RP5C01_MODE; count++, size--) { >> + u8 data; >> + >> + rp5c01_write(priv, >> + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK10, >> + RP5C01_MODE); >> + data = rp5c01_read(priv, pos) << 4; >> + rp5c01_write(priv, >> + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK11, >> + RP5C01_MODE); >> + data |= rp5c01_read(priv, pos++); >> + rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01, >> + RP5C01_MODE); >> + *buf++ = data; >> + } >> + >> + spin_unlock_irq(&priv->lock); >> + return count; >> +} >> + >> +static ssize_t rp5c01_nvram_write(struct file *filp, struct kobject *kobj, >> + struct bin_attribute *bin_attr, >> + char *buf, loff_t pos, size_t size) >> +{ >> + struct device *dev = container_of(kobj, struct device, kobj); >> + struct rp5c01_priv *priv = dev_get_drvdata(dev); >> + ssize_t count; >> + >> + spin_lock_irq(&priv->lock); >> + >> + for (count = 0; size > 0 && pos < RP5C01_MODE; count++, size--) { >> + u8 data = *buf++; >> + >> + rp5c01_write(priv, >> + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK10, >> + RP5C01_MODE); >> + rp5c01_write(priv, data >> 4, pos); >> + rp5c01_write(priv, >> + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK11, >> + RP5C01_MODE); >> + rp5c01_write(priv, data & 0xf, pos++); >> + rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01, >> + RP5C01_MODE); >> + } >> + >> + spin_unlock_irq(&priv->lock); >> + return count; >> +} >> + >> static int __init rp5c01_rtc_probe(struct platform_device *dev) >> { >> struct resource *res; >> @@ -168,6 +240,15 @@ static int __init rp5c01_rtc_probe(struct platform_device *dev) >> goto out_free_priv; >> } >> >> + sysfs_bin_attr_init(&priv->nvram_attr); >> + priv->nvram_attr.attr.name = "nvram"; >> + priv->nvram_attr.attr.mode = S_IRUGO | S_IWUSR; >> + priv->nvram_attr.read = rp5c01_nvram_read; >> + priv->nvram_attr.write = rp5c01_nvram_write; >> + priv->nvram_attr.size = RP5C01_MODE; >> + >> + spin_lock_init(&priv->lock); >> + >> rtc = rtc_device_register("rtc-rp5c01", &dev->dev, &rp5c01_rtc_ops, >> THIS_MODULE); >> if (IS_ERR(rtc)) { >> @@ -177,8 +258,15 @@ static int __init rp5c01_rtc_probe(struct platform_device *dev) >> >> priv->rtc = rtc; >> platform_set_drvdata(dev, priv); >> + >> + error = sysfs_create_bin_file(&dev->dev.kobj, &priv->nvram_attr); >> + if (error) >> + goto out_unregister; >> + >> return 0; >> >> +out_unregister: >> + rtc_device_unregister(rtc); >> out_unmap: >> iounmap(priv->regs); >> out_free_priv: >> @@ -190,6 +278,7 @@ static int __exit rp5c01_rtc_remove(struct platform_device *dev) >> { >> struct rp5c01_priv *priv = platform_get_drvdata(dev); >> >> + sysfs_remove_bin_file(&dev->dev.kobj, &priv->nvram_attr); >> rtc_device_unregister(priv->rtc); >> iounmap(priv->regs); >> kfree(priv); >> -- >> 1.7.0.4 Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Sun, Jun 13, 2010 at 12:12, Geert Uytterhoeven <geert@linux-m68k.org> wrote: > The Ricoh RP5C01 RTC contains 26 x 4 bits of NVRAM. > Provide access to it via a sysfs "nvram" attribute file. I also created a small tool to correct NVRAM checksums, interprete the contents, and modify individual NVRAM fields on Amiga 3000/4000. You can find it at git://git.kernel.org/pub/scm/linux/kernel/git/geert/amiga-nvram.git. BTW, does anyone (Arno?) know the meaning of the AMIX-specific bits (32-63)? battmembitsamix.h just says "See Amix documentation for these bit definitions". I also couldn't find anything about it at http://www.amigaunix.com/. Thx! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Sun, Jun 13, 2010 at 12:12, Geert Uytterhoeven <geert@linux-m68k.org> wrote: > The Ricoh RP5C01 RTC contains 26 x 4 bits of NVRAM. > Provide access to it via a sysfs "nvram" attribute file. > > Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Alessandro: Ping? > -- > Question: Is a spinlock in priv the right kind of locking? > Should I use e.g. rtc-device.ops_lock instead? > > diff --git a/drivers/rtc/rtc-rp5c01.c b/drivers/rtc/rtc-rp5c01.c > index a95f733..36eb661 100644 > --- a/drivers/rtc/rtc-rp5c01.c > +++ b/drivers/rtc/rtc-rp5c01.c > @@ -63,6 +63,8 @@ enum { > struct rp5c01_priv { > u32 __iomem *regs; > struct rtc_device *rtc; > + spinlock_t lock; /* against concurrent RTC/NVRAM access */ > + struct bin_attribute nvram_attr; > }; > > static inline unsigned int rp5c01_read(struct rp5c01_priv *priv, > @@ -92,6 +94,7 @@ static int rp5c01_read_time(struct device *dev, struct rtc_time *tm) > { > struct rp5c01_priv *priv = dev_get_drvdata(dev); > > + spin_lock_irq(&priv->lock); > rp5c01_lock(priv); > > tm->tm_sec = rp5c01_read(priv, RP5C01_10_SECOND) * 10 + > @@ -111,6 +114,7 @@ static int rp5c01_read_time(struct device *dev, struct rtc_time *tm) > tm->tm_year += 100; > > rp5c01_unlock(priv); > + spin_unlock_irq(&priv->lock); > > return rtc_valid_tm(tm); > } > @@ -119,6 +123,7 @@ static int rp5c01_set_time(struct device *dev, struct rtc_time *tm) > { > struct rp5c01_priv *priv = dev_get_drvdata(dev); > > + spin_lock_irq(&priv->lock); > rp5c01_lock(priv); > > rp5c01_write(priv, tm->tm_sec / 10, RP5C01_10_SECOND); > @@ -139,6 +144,7 @@ static int rp5c01_set_time(struct device *dev, struct rtc_time *tm) > rp5c01_write(priv, tm->tm_year % 10, RP5C01_1_YEAR); > > rp5c01_unlock(priv); > + spin_unlock_irq(&priv->lock); > return 0; > } > > @@ -147,6 +153,72 @@ static const struct rtc_class_ops rp5c01_rtc_ops = { > .set_time = rp5c01_set_time, > }; > > + > +/* > + * The NVRAM is organized as 2 blocks of 13 nibbles of 4 bits. > + * We provide access to them like AmigaOS does: the high nibble of each 8-bit > + * byte is stored in BLOCK10, the low nibble in BLOCK11. > + */ > + > +static ssize_t rp5c01_nvram_read(struct file *filp, struct kobject *kobj, > + struct bin_attribute *bin_attr, > + char *buf, loff_t pos, size_t size) > +{ > + struct device *dev = container_of(kobj, struct device, kobj); > + struct rp5c01_priv *priv = dev_get_drvdata(dev); > + ssize_t count; > + > + spin_lock_irq(&priv->lock); > + > + for (count = 0; size > 0 && pos < RP5C01_MODE; count++, size--) { > + u8 data; > + > + rp5c01_write(priv, > + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK10, > + RP5C01_MODE); > + data = rp5c01_read(priv, pos) << 4; > + rp5c01_write(priv, > + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK11, > + RP5C01_MODE); > + data |= rp5c01_read(priv, pos++); > + rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01, > + RP5C01_MODE); > + *buf++ = data; > + } > + > + spin_unlock_irq(&priv->lock); > + return count; > +} > + > +static ssize_t rp5c01_nvram_write(struct file *filp, struct kobject *kobj, > + struct bin_attribute *bin_attr, > + char *buf, loff_t pos, size_t size) > +{ > + struct device *dev = container_of(kobj, struct device, kobj); > + struct rp5c01_priv *priv = dev_get_drvdata(dev); > + ssize_t count; > + > + spin_lock_irq(&priv->lock); > + > + for (count = 0; size > 0 && pos < RP5C01_MODE; count++, size--) { > + u8 data = *buf++; > + > + rp5c01_write(priv, > + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK10, > + RP5C01_MODE); > + rp5c01_write(priv, data >> 4, pos); > + rp5c01_write(priv, > + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK11, > + RP5C01_MODE); > + rp5c01_write(priv, data & 0xf, pos++); > + rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01, > + RP5C01_MODE); > + } > + > + spin_unlock_irq(&priv->lock); > + return count; > +} > + > static int __init rp5c01_rtc_probe(struct platform_device *dev) > { > struct resource *res; > @@ -168,6 +240,15 @@ static int __init rp5c01_rtc_probe(struct platform_device *dev) > goto out_free_priv; > } > > + sysfs_bin_attr_init(&priv->nvram_attr); > + priv->nvram_attr.attr.name = "nvram"; > + priv->nvram_attr.attr.mode = S_IRUGO | S_IWUSR; > + priv->nvram_attr.read = rp5c01_nvram_read; > + priv->nvram_attr.write = rp5c01_nvram_write; > + priv->nvram_attr.size = RP5C01_MODE; > + > + spin_lock_init(&priv->lock); > + > rtc = rtc_device_register("rtc-rp5c01", &dev->dev, &rp5c01_rtc_ops, > THIS_MODULE); > if (IS_ERR(rtc)) { > @@ -177,8 +258,15 @@ static int __init rp5c01_rtc_probe(struct platform_device *dev) > > priv->rtc = rtc; > platform_set_drvdata(dev, priv); > + > + error = sysfs_create_bin_file(&dev->dev.kobj, &priv->nvram_attr); > + if (error) > + goto out_unregister; > + > return 0; > > +out_unregister: > + rtc_device_unregister(rtc); > out_unmap: > iounmap(priv->regs); > out_free_priv: > @@ -190,6 +278,7 @@ static int __exit rp5c01_rtc_remove(struct platform_device *dev) > { > struct rp5c01_priv *priv = platform_get_drvdata(dev); > > + sysfs_remove_bin_file(&dev->dev.kobj, &priv->nvram_attr); > rtc_device_unregister(priv->rtc); > iounmap(priv->regs); > kfree(priv); > -- > 1.7.0.4 Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
diff --git a/drivers/rtc/rtc-rp5c01.c b/drivers/rtc/rtc-rp5c01.c index a95f733..36eb661 100644 --- a/drivers/rtc/rtc-rp5c01.c +++ b/drivers/rtc/rtc-rp5c01.c @@ -63,6 +63,8 @@ enum { struct rp5c01_priv { u32 __iomem *regs; struct rtc_device *rtc; + spinlock_t lock; /* against concurrent RTC/NVRAM access */ + struct bin_attribute nvram_attr; }; static inline unsigned int rp5c01_read(struct rp5c01_priv *priv, @@ -92,6 +94,7 @@ static int rp5c01_read_time(struct device *dev, struct rtc_time *tm) { struct rp5c01_priv *priv = dev_get_drvdata(dev); + spin_lock_irq(&priv->lock); rp5c01_lock(priv); tm->tm_sec = rp5c01_read(priv, RP5C01_10_SECOND) * 10 + @@ -111,6 +114,7 @@ static int rp5c01_read_time(struct device *dev, struct rtc_time *tm) tm->tm_year += 100; rp5c01_unlock(priv); + spin_unlock_irq(&priv->lock); return rtc_valid_tm(tm); } @@ -119,6 +123,7 @@ static int rp5c01_set_time(struct device *dev, struct rtc_time *tm) { struct rp5c01_priv *priv = dev_get_drvdata(dev); + spin_lock_irq(&priv->lock); rp5c01_lock(priv); rp5c01_write(priv, tm->tm_sec / 10, RP5C01_10_SECOND); @@ -139,6 +144,7 @@ static int rp5c01_set_time(struct device *dev, struct rtc_time *tm) rp5c01_write(priv, tm->tm_year % 10, RP5C01_1_YEAR); rp5c01_unlock(priv); + spin_unlock_irq(&priv->lock); return 0; } @@ -147,6 +153,72 @@ static const struct rtc_class_ops rp5c01_rtc_ops = { .set_time = rp5c01_set_time, }; + +/* + * The NVRAM is organized as 2 blocks of 13 nibbles of 4 bits. + * We provide access to them like AmigaOS does: the high nibble of each 8-bit + * byte is stored in BLOCK10, the low nibble in BLOCK11. + */ + +static ssize_t rp5c01_nvram_read(struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t pos, size_t size) +{ + struct device *dev = container_of(kobj, struct device, kobj); + struct rp5c01_priv *priv = dev_get_drvdata(dev); + ssize_t count; + + spin_lock_irq(&priv->lock); + + for (count = 0; size > 0 && pos < RP5C01_MODE; count++, size--) { + u8 data; + + rp5c01_write(priv, + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK10, + RP5C01_MODE); + data = rp5c01_read(priv, pos) << 4; + rp5c01_write(priv, + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK11, + RP5C01_MODE); + data |= rp5c01_read(priv, pos++); + rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01, + RP5C01_MODE); + *buf++ = data; + } + + spin_unlock_irq(&priv->lock); + return count; +} + +static ssize_t rp5c01_nvram_write(struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t pos, size_t size) +{ + struct device *dev = container_of(kobj, struct device, kobj); + struct rp5c01_priv *priv = dev_get_drvdata(dev); + ssize_t count; + + spin_lock_irq(&priv->lock); + + for (count = 0; size > 0 && pos < RP5C01_MODE; count++, size--) { + u8 data = *buf++; + + rp5c01_write(priv, + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK10, + RP5C01_MODE); + rp5c01_write(priv, data >> 4, pos); + rp5c01_write(priv, + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK11, + RP5C01_MODE); + rp5c01_write(priv, data & 0xf, pos++); + rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01, + RP5C01_MODE); + } + + spin_unlock_irq(&priv->lock); + return count; +} + static int __init rp5c01_rtc_probe(struct platform_device *dev) { struct resource *res; @@ -168,6 +240,15 @@ static int __init rp5c01_rtc_probe(struct platform_device *dev) goto out_free_priv; } + sysfs_bin_attr_init(&priv->nvram_attr); + priv->nvram_attr.attr.name = "nvram"; + priv->nvram_attr.attr.mode = S_IRUGO | S_IWUSR; + priv->nvram_attr.read = rp5c01_nvram_read; + priv->nvram_attr.write = rp5c01_nvram_write; + priv->nvram_attr.size = RP5C01_MODE; + + spin_lock_init(&priv->lock); + rtc = rtc_device_register("rtc-rp5c01", &dev->dev, &rp5c01_rtc_ops, THIS_MODULE); if (IS_ERR(rtc)) { @@ -177,8 +258,15 @@ static int __init rp5c01_rtc_probe(struct platform_device *dev) priv->rtc = rtc; platform_set_drvdata(dev, priv); + + error = sysfs_create_bin_file(&dev->dev.kobj, &priv->nvram_attr); + if (error) + goto out_unregister; + return 0; +out_unregister: + rtc_device_unregister(rtc); out_unmap: iounmap(priv->regs); out_free_priv: @@ -190,6 +278,7 @@ static int __exit rp5c01_rtc_remove(struct platform_device *dev) { struct rp5c01_priv *priv = platform_get_drvdata(dev); + sysfs_remove_bin_file(&dev->dev.kobj, &priv->nvram_attr); rtc_device_unregister(priv->rtc); iounmap(priv->regs); kfree(priv);
The Ricoh RP5C01 RTC contains 26 x 4 bits of NVRAM. Provide access to it via a sysfs "nvram" attribute file. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> -- Question: Is a spinlock in priv the right kind of locking? Should I use e.g. rtc-device.ops_lock instead?