Patchwork [PATCHv2,2/6] rtc: rtc-m48t86: add hooks to support driver side memory mapping

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Submitter Alexander Clouter
Date April 2, 2013, 11:04 a.m.
Message ID <1364900675-9632-1-git-send-email-alex@digriz.org.uk>
Download mbox | patch
Permalink /patch/232946/
State New
Headers show

Comments

Alexander Clouter - April 2, 2013, 11:04 a.m.
If platform_data is not defined (as before), then named memory io
ranges need to be defined ("rtc_index" and "rtc_data").  The driver
then maps those regions and uses them as the RTC index and data
addresses.

Changelog:
 v2 - mute GCC warnings (seems to be GCC being dumb)
    - amend the {read,write}byte driver functions to use u8

Signed-off-by: Alexander Clouter <alex@digriz.org.uk>
---
 drivers/rtc/rtc-m48t86.c |  230 ++++++++++++++++++++++++++++++++++------------
 1 file changed, 173 insertions(+), 57 deletions(-)

Patch

diff --git a/drivers/rtc/rtc-m48t86.c b/drivers/rtc/rtc-m48t86.c
index 25e0116..b2cabf9 100644
--- a/drivers/rtc/rtc-m48t86.c
+++ b/drivers/rtc/rtc-m48t86.c
@@ -18,6 +18,8 @@ 
 #include <linux/platform_device.h>
 #include <linux/platform_data/rtc-m48t86.h>
 #include <linux/bcd.h>
+#include <linux/slab.h>
+#include <linux/io.h>
 
 #define M48T86_REG_SEC		0x00
 #define M48T86_REG_SECALRM	0x01
@@ -41,40 +43,70 @@ 
 
 #define DRV_VERSION "0.1"
 
+struct m48t86_rtc_private_data {
+	void __iomem		*io_index;
+	void __iomem		*io_data;
+
+	struct rtc_device	*rtc;
+	struct m48t86_ops	*ops;
+};
+
+static void m48t86_rtc_writebyte(struct device *dev, u8 value, u8 reg)
+{
+	struct m48t86_rtc_private_data *priv = dev_get_drvdata(dev);
+
+	if (priv->ops) {
+		priv->ops->writebyte((unsigned char)value,
+					(unsigned long)reg);
+		return;
+	}
+
+	writeb(reg, priv->io_index);
+	writeb(value, priv->io_data);
+}
+
+static u8 m48t86_rtc_readbyte(struct device *dev, u8 reg)
+{
+	struct m48t86_rtc_private_data *priv = dev_get_drvdata(dev);
+
+	if (priv->ops)
+		return priv->ops->readbyte((unsigned long)reg);
+
+	writeb(reg, priv->io_index);
+	return readb(priv->io_data);
+}
 
 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 = pdev->dev.platform_data;
 
-	reg = ops->readbyte(M48T86_REG_B);
+	reg = m48t86_rtc_readbyte(dev, M48T86_REG_B);
 
 	if (reg & M48T86_REG_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_rtc_readbyte(dev, M48T86_REG_SEC);
+		tm->tm_min	= m48t86_rtc_readbyte(dev, M48T86_REG_MIN);
+		tm->tm_hour	= m48t86_rtc_readbyte(dev, M48T86_REG_HOUR) & 0x3F;
+		tm->tm_mday	= m48t86_rtc_readbyte(dev, M48T86_REG_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_rtc_readbyte(dev, M48T86_REG_MONTH) - 1;
+		tm->tm_year	= m48t86_rtc_readbyte(dev, M48T86_REG_YEAR) + 100;
+		tm->tm_wday	= m48t86_rtc_readbyte(dev, M48T86_REG_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_rtc_readbyte(dev, M48T86_REG_SEC));
+		tm->tm_min	= bcd2bin(m48t86_rtc_readbyte(dev, M48T86_REG_MIN));
+		tm->tm_hour	= bcd2bin(m48t86_rtc_readbyte(dev, M48T86_REG_HOUR) & 0x3F);
+		tm->tm_mday	= bcd2bin(m48t86_rtc_readbyte(dev, M48T86_REG_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_rtc_readbyte(dev, M48T86_REG_MONTH)) - 1;
+		tm->tm_year	= bcd2bin(m48t86_rtc_readbyte(dev, M48T86_REG_YEAR)) + 100;
+		tm->tm_wday	= bcd2bin(m48t86_rtc_readbyte(dev, M48T86_REG_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 (m48t86_rtc_readbyte(dev, M48T86_REG_HOUR) & 0x80)
 			tm->tm_hour += 12;
 
 	return rtc_valid_tm(tm);
@@ -83,38 +115,36 @@  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 = pdev->dev.platform_data;
 
-	reg = ops->readbyte(M48T86_REG_B);
+	reg = m48t86_rtc_readbyte(dev, M48T86_REG_B);
 
 	/* update flag and 24h mode */
 	reg |= M48T86_REG_B_SET | M48T86_REG_B_H24;
-	ops->writebyte(reg, M48T86_REG_B);
+	m48t86_rtc_writebyte(dev, reg, M48T86_REG_B);
 
 	if (reg & M48T86_REG_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_rtc_writebyte(dev, tm->tm_sec, M48T86_REG_SEC);
+		m48t86_rtc_writebyte(dev, tm->tm_min, M48T86_REG_MIN);
+		m48t86_rtc_writebyte(dev, tm->tm_hour, M48T86_REG_HOUR);
+		m48t86_rtc_writebyte(dev, tm->tm_mday, M48T86_REG_DOM);
+		m48t86_rtc_writebyte(dev, tm->tm_mon + 1, M48T86_REG_MONTH);
+		m48t86_rtc_writebyte(dev, tm->tm_year % 100, M48T86_REG_YEAR);
+		m48t86_rtc_writebyte(dev, tm->tm_wday, M48T86_REG_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_rtc_writebyte(dev, bin2bcd(tm->tm_sec), M48T86_REG_SEC);
+		m48t86_rtc_writebyte(dev, bin2bcd(tm->tm_min), M48T86_REG_MIN);
+		m48t86_rtc_writebyte(dev, bin2bcd(tm->tm_hour), M48T86_REG_HOUR);
+		m48t86_rtc_writebyte(dev, bin2bcd(tm->tm_mday), M48T86_REG_DOM);
+		m48t86_rtc_writebyte(dev, bin2bcd(tm->tm_mon + 1), M48T86_REG_MONTH);
+		m48t86_rtc_writebyte(dev, bin2bcd(tm->tm_year % 100), M48T86_REG_YEAR);
+		m48t86_rtc_writebyte(dev, bin2bcd(tm->tm_wday), M48T86_REG_DOW);
 	}
 
 	/* update ended */
 	reg &= ~M48T86_REG_B_SET;
-	ops->writebyte(reg, M48T86_REG_B);
+	m48t86_rtc_writebyte(dev, reg, M48T86_REG_B);
 
 	return 0;
 }
@@ -122,15 +152,13 @@  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 = pdev->dev.platform_data;
 
-	reg = ops->readbyte(M48T86_REG_B);
+	reg = m48t86_rtc_readbyte(dev, M48T86_REG_B);
 
 	seq_printf(seq, "mode\t\t: %s\n",
 		 (reg & M48T86_REG_B_DM) ? "binary" : "bcd");
 
-	reg = ops->readbyte(M48T86_REG_D);
+	reg = m48t86_rtc_readbyte(dev, M48T86_REG_D);
 
 	seq_printf(seq, "battery\t\t: %s\n",
 		 (reg & M48T86_REG_D_VRT) ? "ok" : "exhausted");
@@ -144,34 +172,122 @@  static const struct rtc_class_ops m48t86_rtc_ops = {
 	.proc		= m48t86_rtc_proc,
 };
 
-static int m48t86_rtc_probe(struct platform_device *dev)
+static int m48t86_rtc_probe(struct platform_device *pdev)
 {
 	unsigned char reg;
-	struct m48t86_ops *ops = dev->dev.platform_data;
-	struct rtc_device *rtc = rtc_device_register("m48t86",
-				&dev->dev, &m48t86_rtc_ops, THIS_MODULE);
-
-	if (IS_ERR(rtc))
-		return PTR_ERR(rtc);
-
-	platform_set_drvdata(dev, rtc);
+	int err;
+	struct m48t86_rtc_private_data *priv;
+	struct resource *res_index = NULL;	/* Avoid GCC warning */
+	struct resource *res_data = NULL;	/* Avoid GCC warning */
+
+	/* Allocate memory for the device structure (and zero it) */
+	priv = kzalloc(sizeof(struct m48t86_rtc_private_data), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, priv);
+
+	if (!pdev->dev.platform_data) {
+		res_index = platform_get_resource_byname(
+					pdev, IORESOURCE_MEM, "rtc_index");
+		if (!res_index) {
+			err = -ENXIO;
+			goto out_free;
+		}
+
+		res_data = platform_get_resource_byname(
+					pdev, IORESOURCE_MEM, "rtc_data");
+		if (!res_data) {
+			err = -ENXIO;
+			goto out_free;
+		}
+
+		if (!request_mem_region(res_index->start,
+					resource_size(res_index),
+					dev_name(&pdev->dev))) {
+			err = -EBUSY;
+			goto out_free;
+		}
+
+		if (!request_mem_region(res_data->start,
+					resource_size(res_data),
+					dev_name(&pdev->dev))) {
+			err = -EBUSY;
+			goto out_release_index;
+		}
+
+		priv->io_index = ioremap(res_index->start,
+					resource_size(res_index));
+		if (!priv->io_index) {
+			err = -EIO;
+			goto out_release_data;
+		}
+
+		priv->io_data = ioremap(res_data->start,
+					resource_size(res_data));
+		if (!priv->io_data) {
+			err = -EIO;
+			goto out_io_index;
+		}
+	} else
+		priv->ops = pdev->dev.platform_data;
+
+	priv->rtc = rtc_device_register("m48t86",
+				&pdev->dev, &m48t86_rtc_ops, THIS_MODULE);
+	if (IS_ERR(priv->rtc)) {
+		err = PTR_ERR(priv->rtc);
+		if (!pdev->dev.platform_data)
+			goto out_io_data;
+		else
+			goto out_free;
+	}
 
 	/* read battery status */
-	reg = ops->readbyte(M48T86_REG_D);
-	dev_info(&dev->dev, "battery %s\n",
+	reg = m48t86_rtc_readbyte(&pdev->dev, M48T86_REG_D);
+	dev_info(&pdev->dev, "battery %s\n",
 		(reg & M48T86_REG_D_VRT) ? "ok" : "exhausted");
 
 	return 0;
+
+out_io_data:
+	iounmap(priv->io_data);
+out_io_index:
+	iounmap(priv->io_index);
+out_release_data:
+	release_mem_region(res_data->start, resource_size(res_data));
+out_release_index:
+	release_mem_region(res_index->start, resource_size(res_index));
+out_free:
+	platform_set_drvdata(pdev, NULL);
+	kfree(priv);
+	return err;
 }
 
-static int m48t86_rtc_remove(struct platform_device *dev)
+static int m48t86_rtc_remove(struct platform_device *pdev)
 {
-	struct rtc_device *rtc = platform_get_drvdata(dev);
+	struct resource *res;
+	struct m48t86_rtc_private_data *priv = platform_get_drvdata(pdev);
+
+	if (priv->rtc)
+		rtc_device_unregister(priv->rtc);
+
+	if (priv->io_data) {
+		iounmap(priv->io_data);
+		res = platform_get_resource_byname(
+					pdev, IORESOURCE_MEM, "rtc_data");
+		release_mem_region(res->start, resource_size(res));
+	}
+
+	if (priv->io_index) {
+		iounmap(priv->io_index);
+		res = platform_get_resource_byname(
+					pdev, IORESOURCE_MEM, "rtc_index");
+		release_mem_region(res->start, resource_size(res));
+	}
 
- 	if (rtc)
-		rtc_device_unregister(rtc);
+	platform_set_drvdata(pdev, NULL);
 
-	platform_set_drvdata(dev, NULL);
+	kfree(priv);
 
 	return 0;
 }