rtc-m48t59: add support for M48T02 and M48T59 chips

Add support for two compatible RTC:
- M48T08 which does not have alarm part,
- M48T08 which does not have alarm part and has
  only 2KB of NVRAM

These types covers all Mostek's RTC used in Sun UltraSparc workstations.

Tested on Sun Ultra60 with M48T59 RTC.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 44 insertions, 10 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index ecdff200247..daf08fe980d 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -406,10 +406,13 @@ config RTC_DRV_M48T86
 	  will be called rtc-m48t86.
 
 config RTC_DRV_M48T59
-	tristate "ST M48T59"
+	tristate "ST M48T59/M48T08/M48T02"
 	help
 	  If you say Y here you will get support for the
-	  ST M48T59 RTC chip.
+	  ST M48T59 RTC chip and compatible ST M48T08 and M48T02.
+
+	  These chips are usually found in Sun SPARC and UltraSPARC
+	  workstations.
 
 	  This driver can also be built as a module, if so, the module
 	  will be called "rtc-m48t59".
diff --git a/drivers/rtc/rtc-m48t59.c b/drivers/rtc/rtc-m48t59.c
index e085ab2c3db..50f9f10b32f 100644
--- a/drivers/rtc/rtc-m48t59.c
+++ b/drivers/rtc/rtc-m48t59.c
@@ -24,8 +24,9 @@
 #define NO_IRQ	(-1)
 #endif
 
-#define M48T59_READ(reg)	pdata->read_byte(dev, reg)
-#define M48T59_WRITE(val, reg)	pdata->write_byte(dev, reg, val)
+#define M48T59_READ(reg) (pdata->read_byte(dev, pdata->offset + reg))
+#define M48T59_WRITE(val, reg) \
+	(pdata->write_byte(dev, pdata->offset + reg, val))
 
 #define M48T59_SET_BITS(mask, reg)	\
 	M48T59_WRITE((M48T59_READ(reg) | (mask)), (reg))
@@ -309,6 +310,11 @@ static const struct rtc_class_ops m48t59_rtc_ops = {
 	.proc		= m48t59_rtc_proc,
 };
 
+static const struct rtc_class_ops m48t02_rtc_ops = {
+	.read_time	= m48t59_rtc_read_time,
+	.set_time	= m48t59_rtc_set_time,
+};
+
 static ssize_t m48t59_nvram_read(struct kobject *kobj,
 				struct bin_attribute *bin_attr,
 				char *buf, loff_t pos, size_t size)
@@ -320,7 +326,7 @@ static ssize_t m48t59_nvram_read(struct kobject *kobj,
 	ssize_t cnt = 0;
 	unsigned long flags;
 
-	for (; size > 0 && pos < M48T59_NVRAM_SIZE; cnt++, size--) {
+	for (; size > 0 && pos < pdata->offset; cnt++, size--) {
 		spin_lock_irqsave(&m48t59->lock, flags);
 		*buf++ = M48T59_READ(cnt);
 		spin_unlock_irqrestore(&m48t59->lock, flags);
@@ -340,7 +346,7 @@ static ssize_t m48t59_nvram_write(struct kobject *kobj,
 	ssize_t cnt = 0;
 	unsigned long flags;
 
-	for (; size > 0 && pos < M48T59_NVRAM_SIZE; cnt++, size--) {
+	for (; size > 0 && pos < pdata->offset; cnt++, size--) {
 		spin_lock_irqsave(&m48t59->lock, flags);
 		M48T59_WRITE(*buf++, cnt);
 		spin_unlock_irqrestore(&m48t59->lock, flags);
@@ -357,7 +363,6 @@ static struct bin_attribute m48t59_nvram_attr = {
 	},
 	.read = m48t59_nvram_read,
 	.write = m48t59_nvram_write,
-	.size = M48T59_NVRAM_SIZE,
 };
 
 static int __devinit m48t59_rtc_probe(struct platform_device *pdev)
@@ -366,6 +371,8 @@ static int __devinit m48t59_rtc_probe(struct platform_device *pdev)
 	struct m48t59_private *m48t59 = NULL;
 	struct resource *res;
 	int ret = -ENOMEM;
+	char *name;
+	const struct rtc_class_ops *ops;
 
 	/* This chip could be memory-mapped or I/O-mapped */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -390,6 +397,8 @@ static int __devinit m48t59_rtc_probe(struct platform_device *pdev)
 			/* Ensure we only kmalloc platform data once */
 			pdev->dev.platform_data = pdata;
 		}
+		if (!pdata->type)
+			pdata->type = M48T59RTC_TYPE_M48T59;
 
 		/* Try to use the generic memory read/write ops */
 		if (!pdata->write_byte)
@@ -419,14 +428,36 @@ static int __devinit m48t59_rtc_probe(struct platform_device *pdev)
 		if (ret)
 			goto out;
 	}
+	switch (pdata->type) {
+	case M48T59RTC_TYPE_M48T59:
+		name = "m48t59";
+		ops = &m48t59_rtc_ops;
+		pdata->offset = 0x1ff0;
+		break;
+	case M48T59RTC_TYPE_M48T02:
+		name = "m48t02";
+		ops = &m48t02_rtc_ops;
+		pdata->offset = 0x7f0;
+		break;
+	case M48T59RTC_TYPE_M48T08:
+		name = "m48t08";
+		ops = &m48t02_rtc_ops;
+		pdata->offset = 0x1ff0;
+		break;
+	default:
+		dev_err(&pdev->dev, "Unknown RTC type\n");
+		ret = -ENODEV;
+		goto out;
+	}
 
-	m48t59->rtc = rtc_device_register("m48t59", &pdev->dev,
-				&m48t59_rtc_ops, THIS_MODULE);
+	m48t59->rtc = rtc_device_register(name, &pdev->dev, ops, THIS_MODULE);
 	if (IS_ERR(m48t59->rtc)) {
 		ret = PTR_ERR(m48t59->rtc);
 		goto out;
 	}
 
+	m48t59_nvram_attr.size = pdata->offset;
+
 	ret = sysfs_create_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr);
 	if (ret)
 		goto out;
@@ -489,5 +520,5 @@ module_init(m48t59_rtc_init);
 module_exit(m48t59_rtc_exit);
 
 MODULE_AUTHOR("Mark Zhan <rongkai.zhan@windriver.com>");
-MODULE_DESCRIPTION("M48T59 RTC driver");
+MODULE_DESCRIPTION("M48T59/M48T02/M48T08 RTC driver");
 MODULE_LICENSE("GPL");