1 files changed, 193 insertions, 79 deletions

diff --git a/drivers/rtc/rtc-m48t86.c b/drivers/rtc/rtc-m48t86.c
index 0eeb5714c00f..02af045305dd 100644
--- a/drivers/rtc/rtc-m48t86.c
+++ b/drivers/rtc/rtc-m48t86.c
@@ -16,62 +16,88 @@
 #include <linux/module.h>
 #include <linux/rtc.h>
 #include <linux/platform_device.h>
-#include <linux/platform_data/rtc-m48t86.h>
 #include <linux/bcd.h>
+#include <linux/io.h>
 
-#define M48T86_REG_SEC		0x00
-#define M48T86_REG_SECALRM	0x01
-#define M48T86_REG_MIN		0x02
-#define M48T86_REG_MINALRM	0x03
-#define M48T86_REG_HOUR		0x04
-#define M48T86_REG_HOURALRM	0x05
-#define M48T86_REG_DOW		0x06 /* 1 = sunday */
-#define M48T86_REG_DOM		0x07
-#define M48T86_REG_MONTH	0x08 /* 1 - 12 */
-#define M48T86_REG_YEAR		0x09 /* 0 - 99 */
-#define M48T86_REG_A		0x0A
-#define M48T86_REG_B		0x0B
-#define M48T86_REG_C		0x0C
-#define M48T86_REG_D		0x0D
-
-#define M48T86_REG_B_H24	(1 << 1)
-#define M48T86_REG_B_DM		(1 << 2)
-#define M48T86_REG_B_SET	(1 << 7)
-#define M48T86_REG_D_VRT	(1 << 7)
+#define M48T86_SEC		0x00
+#define M48T86_SECALRM		0x01
+#define M48T86_MIN		0x02
+#define M48T86_MINALRM		0x03
+#define M48T86_HOUR		0x04
+#define M48T86_HOURALRM		0x05
+#define M48T86_DOW		0x06 /* 1 = sunday */
+#define M48T86_DOM		0x07
+#define M48T86_MONTH		0x08 /* 1 - 12 */
+#define M48T86_YEAR		0x09 /* 0 - 99 */
+#define M48T86_A		0x0a
+#define M48T86_B		0x0b
+#define M48T86_B_SET		BIT(7)
+#define M48T86_B_DM		BIT(2)
+#define M48T86_B_H24		BIT(1)
+#define M48T86_C		0x0c
+#define M48T86_D		0x0d
+#define M48T86_D_VRT		BIT(7)
+#define M48T86_NVRAM(x)		(0x0e + (x))
+#define M48T86_NVRAM_LEN	114
+
+struct m48t86_rtc_info {
+	void __iomem *index_reg;
+	void __iomem *data_reg;
+	struct rtc_device *rtc;
+};
+
+static unsigned char m48t86_readb(struct device *dev, unsigned long addr)
+{
+	struct m48t86_rtc_info *info = dev_get_drvdata(dev);
+	unsigned char value;
+
+	writeb(addr, info->index_reg);
+	value = readb(info->data_reg);
+
+	return value;
+}
+
+static void m48t86_writeb(struct device *dev,
+			  unsigned char value, unsigned long addr)
+{
+	struct m48t86_rtc_info *info = dev_get_drvdata(dev);
+
+	writeb(addr, info->index_reg);
+	writeb(value, info->data_reg);
+}
 
 static int m48t86_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
 	unsigned char reg;
-	struct platform_device *pdev = to_platform_device(dev);
-	struct m48t86_ops *ops = dev_get_platdata(&pdev->dev);
 
-	reg = ops->readbyte(M48T86_REG_B);
+	reg = m48t86_readb(dev, M48T86_B);
 
-	if (reg & M48T86_REG_B_DM) {
+	if (reg & M48T86_B_DM) {
 		/* data (binary) mode */
-		tm->tm_sec	= ops->readbyte(M48T86_REG_SEC);
-		tm->tm_min	= ops->readbyte(M48T86_REG_MIN);
-		tm->tm_hour	= ops->readbyte(M48T86_REG_HOUR) & 0x3F;
-		tm->tm_mday	= ops->readbyte(M48T86_REG_DOM);
+		tm->tm_sec	= m48t86_readb(dev, M48T86_SEC);
+		tm->tm_min	= m48t86_readb(dev, M48T86_MIN);
+		tm->tm_hour	= m48t86_readb(dev, M48T86_HOUR) & 0x3f;
+		tm->tm_mday	= m48t86_readb(dev, M48T86_DOM);
 		/* tm_mon is 0-11 */
-		tm->tm_mon	= ops->readbyte(M48T86_REG_MONTH) - 1;
-		tm->tm_year	= ops->readbyte(M48T86_REG_YEAR) + 100;
-		tm->tm_wday	= ops->readbyte(M48T86_REG_DOW);
+		tm->tm_mon	= m48t86_readb(dev, M48T86_MONTH) - 1;
+		tm->tm_year	= m48t86_readb(dev, M48T86_YEAR) + 100;
+		tm->tm_wday	= m48t86_readb(dev, M48T86_DOW);
 	} else {
 		/* bcd mode */
-		tm->tm_sec	= bcd2bin(ops->readbyte(M48T86_REG_SEC));
-		tm->tm_min	= bcd2bin(ops->readbyte(M48T86_REG_MIN));
-		tm->tm_hour	= bcd2bin(ops->readbyte(M48T86_REG_HOUR) & 0x3F);
-		tm->tm_mday	= bcd2bin(ops->readbyte(M48T86_REG_DOM));
+		tm->tm_sec	= bcd2bin(m48t86_readb(dev, M48T86_SEC));
+		tm->tm_min	= bcd2bin(m48t86_readb(dev, M48T86_MIN));
+		tm->tm_hour	= bcd2bin(m48t86_readb(dev, M48T86_HOUR) &
+					  0x3f);
+		tm->tm_mday	= bcd2bin(m48t86_readb(dev, M48T86_DOM));
 		/* tm_mon is 0-11 */
-		tm->tm_mon	= bcd2bin(ops->readbyte(M48T86_REG_MONTH)) - 1;
-		tm->tm_year	= bcd2bin(ops->readbyte(M48T86_REG_YEAR)) + 100;
-		tm->tm_wday	= bcd2bin(ops->readbyte(M48T86_REG_DOW));
+		tm->tm_mon	= bcd2bin(m48t86_readb(dev, M48T86_MONTH)) - 1;
+		tm->tm_year	= bcd2bin(m48t86_readb(dev, M48T86_YEAR)) + 100;
+		tm->tm_wday	= bcd2bin(m48t86_readb(dev, M48T86_DOW));
 	}
 
 	/* correct the hour if the clock is in 12h mode */
-	if (!(reg & M48T86_REG_B_H24))
-		if (ops->readbyte(M48T86_REG_HOUR) & 0x80)
+	if (!(reg & M48T86_B_H24))
+		if (m48t86_readb(dev, M48T86_HOUR) & 0x80)
 			tm->tm_hour += 12;
 
 	return rtc_valid_tm(tm);
@@ -80,38 +106,36 @@ static int m48t86_rtc_read_time(struct device *dev, struct rtc_time *tm)
 static int m48t86_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
 	unsigned char reg;
-	struct platform_device *pdev = to_platform_device(dev);
-	struct m48t86_ops *ops = dev_get_platdata(&pdev->dev);
 
-	reg = ops->readbyte(M48T86_REG_B);
+	reg = m48t86_readb(dev, M48T86_B);
 
 	/* update flag and 24h mode */
-	reg |= M48T86_REG_B_SET | M48T86_REG_B_H24;
-	ops->writebyte(reg, M48T86_REG_B);
+	reg |= M48T86_B_SET | M48T86_B_H24;
+	m48t86_writeb(dev, reg, M48T86_B);
 
-	if (reg & M48T86_REG_B_DM) {
+	if (reg & M48T86_B_DM) {
 		/* data (binary) mode */
-		ops->writebyte(tm->tm_sec, M48T86_REG_SEC);
-		ops->writebyte(tm->tm_min, M48T86_REG_MIN);
-		ops->writebyte(tm->tm_hour, M48T86_REG_HOUR);
-		ops->writebyte(tm->tm_mday, M48T86_REG_DOM);
-		ops->writebyte(tm->tm_mon + 1, M48T86_REG_MONTH);
-		ops->writebyte(tm->tm_year % 100, M48T86_REG_YEAR);
-		ops->writebyte(tm->tm_wday, M48T86_REG_DOW);
+		m48t86_writeb(dev, tm->tm_sec, M48T86_SEC);
+		m48t86_writeb(dev, tm->tm_min, M48T86_MIN);
+		m48t86_writeb(dev, tm->tm_hour, M48T86_HOUR);
+		m48t86_writeb(dev, tm->tm_mday, M48T86_DOM);
+		m48t86_writeb(dev, tm->tm_mon + 1, M48T86_MONTH);
+		m48t86_writeb(dev, tm->tm_year % 100, M48T86_YEAR);
+		m48t86_writeb(dev, tm->tm_wday, M48T86_DOW);
 	} else {
 		/* bcd mode */
-		ops->writebyte(bin2bcd(tm->tm_sec), M48T86_REG_SEC);
-		ops->writebyte(bin2bcd(tm->tm_min), M48T86_REG_MIN);
-		ops->writebyte(bin2bcd(tm->tm_hour), M48T86_REG_HOUR);
-		ops->writebyte(bin2bcd(tm->tm_mday), M48T86_REG_DOM);
-		ops->writebyte(bin2bcd(tm->tm_mon + 1), M48T86_REG_MONTH);
-		ops->writebyte(bin2bcd(tm->tm_year % 100), M48T86_REG_YEAR);
-		ops->writebyte(bin2bcd(tm->tm_wday), M48T86_REG_DOW);
+		m48t86_writeb(dev, bin2bcd(tm->tm_sec), M48T86_SEC);
+		m48t86_writeb(dev, bin2bcd(tm->tm_min), M48T86_MIN);
+		m48t86_writeb(dev, bin2bcd(tm->tm_hour), M48T86_HOUR);
+		m48t86_writeb(dev, bin2bcd(tm->tm_mday), M48T86_DOM);
+		m48t86_writeb(dev, bin2bcd(tm->tm_mon + 1), M48T86_MONTH);
+		m48t86_writeb(dev, bin2bcd(tm->tm_year % 100), M48T86_YEAR);
+		m48t86_writeb(dev, bin2bcd(tm->tm_wday), M48T86_DOW);
 	}
 
 	/* update ended */
-	reg &= ~M48T86_REG_B_SET;
-	ops->writebyte(reg, M48T86_REG_B);
+	reg &= ~M48T86_B_SET;
+	m48t86_writeb(dev, reg, M48T86_B);
 
 	return 0;
 }
@@ -119,18 +143,16 @@ static int m48t86_rtc_set_time(struct device *dev, struct rtc_time *tm)
 static int m48t86_rtc_proc(struct device *dev, struct seq_file *seq)
 {
 	unsigned char reg;
-	struct platform_device *pdev = to_platform_device(dev);
-	struct m48t86_ops *ops = dev_get_platdata(&pdev->dev);
 
-	reg = ops->readbyte(M48T86_REG_B);
+	reg = m48t86_readb(dev, M48T86_B);
 
 	seq_printf(seq, "mode\t\t: %s\n",
-		 (reg & M48T86_REG_B_DM) ? "binary" : "bcd");
+		   (reg & M48T86_B_DM) ? "binary" : "bcd");
 
-	reg = ops->readbyte(M48T86_REG_D);
+	reg = m48t86_readb(dev, M48T86_D);
 
 	seq_printf(seq, "battery\t\t: %s\n",
-		 (reg & M48T86_REG_D_VRT) ? "ok" : "exhausted");
+		   (reg & M48T86_D_VRT) ? "ok" : "exhausted");
 
 	return 0;
 }
@@ -141,25 +163,116 @@ static const struct rtc_class_ops m48t86_rtc_ops = {
 	.proc		= m48t86_rtc_proc,
 };
 
-static int m48t86_rtc_probe(struct platform_device *dev)
+static ssize_t m48t86_nvram_read(struct file *filp, struct kobject *kobj,
+				 struct bin_attribute *attr,
+				 char *buf, loff_t off, size_t count)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	unsigned int i;
+
+	for (i = 0; i < count; i++)
+		buf[i] = m48t86_readb(dev, M48T86_NVRAM(off + i));
+
+	return count;
+}
+
+static ssize_t m48t86_nvram_write(struct file *filp, struct kobject *kobj,
+				  struct bin_attribute *attr,
+				  char *buf, loff_t off, size_t count)
 {
+	struct device *dev = kobj_to_dev(kobj);
+	unsigned int i;
+
+	for (i = 0; i < count; i++)
+		m48t86_writeb(dev, buf[i], M48T86_NVRAM(off + i));
+
+	return count;
+}
+
+static BIN_ATTR(nvram, 0644, m48t86_nvram_read, m48t86_nvram_write,
+		M48T86_NVRAM_LEN);
+
+/*
+ * The RTC is an optional feature at purchase time on some Technologic Systems
+ * boards. Verify that it actually exists by checking if the last two bytes
+ * of the NVRAM can be changed.
+ *
+ * This is based on the method used in their rtc7800.c example.
+ */
+static bool m48t86_verify_chip(struct platform_device *pdev)
+{
+	unsigned int offset0 = M48T86_NVRAM(M48T86_NVRAM_LEN - 2);
+	unsigned int offset1 = M48T86_NVRAM(M48T86_NVRAM_LEN - 1);
+	unsigned char tmp0, tmp1;
+
+	tmp0 = m48t86_readb(&pdev->dev, offset0);
+	tmp1 = m48t86_readb(&pdev->dev, offset1);
+
+	m48t86_writeb(&pdev->dev, 0x00, offset0);
+	m48t86_writeb(&pdev->dev, 0x55, offset1);
+	if (m48t86_readb(&pdev->dev, offset1) == 0x55) {
+		m48t86_writeb(&pdev->dev, 0xaa, offset1);
+		if (m48t86_readb(&pdev->dev, offset1) == 0xaa &&
+		    m48t86_readb(&pdev->dev, offset0) == 0x00) {
+			m48t86_writeb(&pdev->dev, tmp0, offset0);
+			m48t86_writeb(&pdev->dev, tmp1, offset1);
+
+			return true;
+		}
+	}
+	return false;
+}
+
+static int m48t86_rtc_probe(struct platform_device *pdev)
+{
+	struct m48t86_rtc_info *info;
+	struct resource *res;
 	unsigned char reg;
-	struct m48t86_ops *ops = dev_get_platdata(&dev->dev);
-	struct rtc_device *rtc;
 
-	rtc = devm_rtc_device_register(&dev->dev, "m48t86",
-				&m48t86_rtc_ops, THIS_MODULE);
+	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+	info->index_reg = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(info->index_reg))
+		return PTR_ERR(info->index_reg);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res)
+		return -ENODEV;
+	info->data_reg = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(info->data_reg))
+		return PTR_ERR(info->data_reg);
 
-	if (IS_ERR(rtc))
-		return PTR_ERR(rtc);
+	dev_set_drvdata(&pdev->dev, info);
+
+	if (!m48t86_verify_chip(pdev)) {
+		dev_info(&pdev->dev, "RTC not present\n");
+		return -ENODEV;
+	}
 
-	platform_set_drvdata(dev, rtc);
+	info->rtc = devm_rtc_device_register(&pdev->dev, "m48t86",
+					     &m48t86_rtc_ops, THIS_MODULE);
+	if (IS_ERR(info->rtc))
+		return PTR_ERR(info->rtc);
 
 	/* read battery status */
-	reg = ops->readbyte(M48T86_REG_D);
-	dev_info(&dev->dev, "battery %s\n",
-		(reg & M48T86_REG_D_VRT) ? "ok" : "exhausted");
+	reg = m48t86_readb(&pdev->dev, M48T86_D);
+	dev_info(&pdev->dev, "battery %s\n",
+		 (reg & M48T86_D_VRT) ? "ok" : "exhausted");
 
+	if (device_create_bin_file(&pdev->dev, &bin_attr_nvram))
+		dev_err(&pdev->dev, "failed to create nvram sysfs entry\n");
+
+	return 0;
+}
+
+static int m48t86_rtc_remove(struct platform_device *pdev)
+{
+	device_remove_bin_file(&pdev->dev, &bin_attr_nvram);
 	return 0;
 }
 
@@ -168,6 +281,7 @@ static struct platform_driver m48t86_rtc_platform_driver = {
 		.name	= "rtc-m48t86",
 	},
 	.probe		= m48t86_rtc_probe,
+	.remove		= m48t86_rtc_remove,
 };
 
 module_platform_driver(m48t86_rtc_platform_driver);