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Commit 22e3d631 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Linus Torvalds
Browse files

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: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent de639c31

drivers/rtc/rtc-rp5c01.c

+89 −0
Original line number Diff line number Diff line
@@ -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);