From 22e3d63147c9608dc48ac6a6d9973eba8672efbe Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 10 Aug 2010 18:02:22 -0700 Subject: rtc: rp5c01: add NVRAM support 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 Cc: Wan ZongShun Cc: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-rp5c01.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) (limited to 'drivers/rtc') diff --git a/drivers/rtc/rtc-rp5c01.c b/drivers/rtc/rtc-rp5c01.c index a95f733bb15..36eb6618446 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); -- cgit v1.2.3