rtc: rtc-max6902 fixes

- no changelogs in code
- no banners
- use local buffers
- fix probe sequence
- fixed style issues
- fix spi_write call
- removed old debug code

replaces http://patchwork.ozlabs.org/patch/9421/
and http://patchwork.ozlabs.org/patch/9455/

Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: David Brownell <david-b@pacbell.net>
Cc: Raphael Assenat <raph@raphnet.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 38 insertions, 138 deletions

diff --git a/drivers/rtc/rtc-max6902.c b/drivers/rtc/rtc-max6902.c
index 2f6507df7b49..36a8ea9ed8ba 100644
--- a/drivers/rtc/rtc-max6902.c
+++ b/drivers/rtc/rtc-max6902.c
@@ -9,14 +9,6 @@
  *
  * Driver for MAX6902 spi RTC
  *
- * Changelog:
- *
- * 24-May-2006: Raphael Assenat <raph@8d.com>
- *                - Major rework
- *                              Converted to rtc_device and uses the SPI layer.
- *
- * ??-???-2005: Someone at Compulab
- *                - Initial driver creation.
  */
 
 #include <linux/module.h>
@@ -26,7 +18,6 @@
 #include <linux/rtc.h>
 #include <linux/spi/spi.h>
 #include <linux/bcd.h>
-#include <linux/delay.h>
 
 #define MAX6902_REG_SECONDS             0x01
 #define MAX6902_REG_MINUTES             0x03
@@ -38,16 +29,7 @@
 #define MAX6902_REG_CONTROL             0x0F
 #define MAX6902_REG_CENTURY             0x13
 
-#undef MAX6902_DEBUG
-
-struct max6902 {
-        struct rtc_device *rtc;
-        u8 buf[9]; /* Burst read cmd + 8 registers */
-        u8 tx_buf[2];
-        u8 rx_buf[2];
-};
-
-static void max6902_set_reg(struct device *dev, unsigned char address,
+static int max6902_set_reg(struct device *dev, unsigned char address,
                                 unsigned char data)
 {
         struct spi_device *spi = to_spi_device(dev);
@@ -57,113 +39,58 @@ static void max6902_set_reg(struct device *dev, unsigned char address,
         buf[0] = address & 0x7f;
         buf[1] = data;
 
-        spi_write(spi, buf, 2);
+        return spi_write_then_read(spi, buf, 2, NULL, 0);
 }
 
 static int max6902_get_reg(struct device *dev, unsigned char address,
                                 unsigned char *data)
 {
         struct spi_device *spi = to_spi_device(dev);
-        struct max6902 *chip = dev_get_drvdata(dev);
-        struct spi_message message;
-        struct spi_transfer xfer;
-        int status;
-
-        if (!data)
-                return -EINVAL;
-
-        /* Build our spi message */
-        spi_message_init(&message);
-        memset(&xfer, 0, sizeof(xfer));
-        xfer.len = 2;
-        /* Can tx_buf and rx_buf be equal? The doc in spi.h is not sure... */
-        xfer.tx_buf = chip->tx_buf;
-        xfer.rx_buf = chip->rx_buf;
 
         /* Set MSB to indicate read */
-        chip->tx_buf[0] = address | 0x80;
-
-        spi_message_add_tail(&xfer, &message);
+        *data = address | 0x80;
 
-        /* do the i/o */
-        status = spi_sync(spi, &message);
-
-        if (status == 0)
-                *data = chip->rx_buf[1];
-        return status;
+        return spi_write_then_read(spi, data, 1, data, 1);
 }
 
-static int max6902_get_datetime(struct device *dev, struct rtc_time *dt)
+static int max6902_read_time(struct device *dev, struct rtc_time *dt)
 {
-        unsigned char tmp;
-        int century;
-        int err;
+        int err, century;
         struct spi_device *spi = to_spi_device(dev);
-        struct max6902 *chip = dev_get_drvdata(dev);
-        struct spi_message message;
-        struct spi_transfer xfer;
-        int status;
+        unsigned char buf[8];
 
-        err = max6902_get_reg(dev, MAX6902_REG_CENTURY, &tmp);
-        if (err)
-                return err;
-
-        /* build the message */
-        spi_message_init(&message);
-        memset(&xfer, 0, sizeof(xfer));
-        xfer.len = 1 + 7;       /* Burst read command + 7 registers */
-        xfer.tx_buf = chip->buf;
-        xfer.rx_buf = chip->buf;
-        chip->buf[0] = 0xbf;    /* Burst read */
-        spi_message_add_tail(&xfer, &message);
+        buf[0] = 0xbf;  /* Burst read */
 
-        /* do the i/o */
-        status = spi_sync(spi, &message);
-        if (status)
-                return status;
+        err = spi_write_then_read(spi, buf, 1, buf, 8);
+        if (err != 0)
+                return err;
 
         /* The chip sends data in this order:
          * Seconds, Minutes, Hours, Date, Month, Day, Year */
-        dt->tm_sec      = bcd2bin(chip->buf[1]);
-        dt->tm_min      = bcd2bin(chip->buf[2]);
-        dt->tm_hour     = bcd2bin(chip->buf[3]);
-        dt->tm_mday     = bcd2bin(chip->buf[4]);
-        dt->tm_mon      = bcd2bin(chip->buf[5]) - 1;
-        dt->tm_wday     = bcd2bin(chip->buf[6]);
-        dt->tm_year = bcd2bin(chip->buf[7]);
+        dt->tm_sec      = bcd2bin(buf[0]);
+        dt->tm_min      = bcd2bin(buf[1]);
+        dt->tm_hour     = bcd2bin(buf[2]);
+        dt->tm_mday     = bcd2bin(buf[3]);
+        dt->tm_mon      = bcd2bin(buf[4]) - 1;
+        dt->tm_wday     = bcd2bin(buf[5]);
+        dt->tm_year     = bcd2bin(buf[6]);
+
+        /* Read century */
+        err = max6902_get_reg(dev, MAX6902_REG_CENTURY, &buf[0]);
+        if (err != 0)
+                return err;
 
-        century = bcd2bin(tmp) * 100;
+        century = bcd2bin(buf[0]) * 100;
 
         dt->tm_year += century;
         dt->tm_year -= 1900;
 
-#ifdef MAX6902_DEBUG
-        printk("\n%s : Read RTC values\n",__func__);
-        printk("tm_hour: %i\n",dt->tm_hour);
-        printk("tm_min : %i\n",dt->tm_min);
-        printk("tm_sec : %i\n",dt->tm_sec);
-        printk("tm_year: %i\n",dt->tm_year);
-        printk("tm_mon : %i\n",dt->tm_mon);
-        printk("tm_mday: %i\n",dt->tm_mday);
-        printk("tm_wday: %i\n",dt->tm_wday);
-#endif
-
-        return 0;
+        return rtc_valid_tm(dt);
 }
 
-static int max6902_set_datetime(struct device *dev, struct rtc_time *dt)
+static int max6902_set_time(struct device *dev, struct rtc_time *dt)
 {
-        dt->tm_year = dt->tm_year+1900;
-
-#ifdef MAX6902_DEBUG
-        printk("\n%s : Setting RTC values\n",__func__);
-        printk("tm_sec : %i\n",dt->tm_sec);
-        printk("tm_min : %i\n",dt->tm_min);
-        printk("tm_hour: %i\n",dt->tm_hour);
-        printk("tm_mday: %i\n",dt->tm_mday);
-        printk("tm_wday: %i\n",dt->tm_wday);
-        printk("tm_year: %i\n",dt->tm_year);
-#endif
+        dt->tm_year = dt->tm_year + 1900;
 
         /* Remove write protection */
         max6902_set_reg(dev, 0xF, 0);
@@ -173,10 +100,10 @@ static int max6902_set_datetime(struct device *dev, struct rtc_time *dt)
         max6902_set_reg(dev, 0x05, bin2bcd(dt->tm_hour));
 
         max6902_set_reg(dev, 0x07, bin2bcd(dt->tm_mday));
-        max6902_set_reg(dev, 0x09, bin2bcd(dt->tm_mon+1));
+        max6902_set_reg(dev, 0x09, bin2bcd(dt->tm_mon + 1));
         max6902_set_reg(dev, 0x0B, bin2bcd(dt->tm_wday));
-        max6902_set_reg(dev, 0x0D, bin2bcd(dt->tm_year%100));
-        max6902_set_reg(dev, 0x13, bin2bcd(dt->tm_year/100));
+        max6902_set_reg(dev, 0x0D, bin2bcd(dt->tm_year % 100));
+        max6902_set_reg(dev, 0x13, bin2bcd(dt->tm_year / 100));
 
         /* Compulab used a delay here. However, the datasheet
          * does not mention a delay being required anywhere... */
@@ -188,16 +115,6 @@ static int max6902_set_datetime(struct device *dev, struct rtc_time *dt)
         return 0;
 }
 
-static int max6902_read_time(struct device *dev, struct rtc_time *tm)
-{
-        return max6902_get_datetime(dev, tm);
-}
-
-static int max6902_set_time(struct device *dev, struct rtc_time *tm)
-{
-        return max6902_set_datetime(dev, tm);
-}
-
 static const struct rtc_class_ops max6902_rtc_ops = {
         .read_time      = max6902_read_time,
         .set_time       = max6902_set_time,
@@ -207,45 +124,29 @@ static int __devinit max6902_probe(struct spi_device *spi)
 {
         struct rtc_device *rtc;
         unsigned char tmp;
-        struct max6902 *chip;
         int res;
 
-        rtc = rtc_device_register("max6902",
-                                &spi->dev, &max6902_rtc_ops, THIS_MODULE);
-        if (IS_ERR(rtc))
-                return PTR_ERR(rtc);
-
         spi->mode = SPI_MODE_3;
         spi->bits_per_word = 8;
         spi_setup(spi);
 
-        chip = kzalloc(sizeof *chip, GFP_KERNEL);
-        if (!chip) {
-                rtc_device_unregister(rtc);
-                return -ENOMEM;
-        }
-        chip->rtc = rtc;
-        dev_set_drvdata(&spi->dev, chip);
-
         res = max6902_get_reg(&spi->dev, MAX6902_REG_SECONDS, &tmp);
-        if (res) {
-                rtc_device_unregister(rtc);
+        if (res != 0)
                 return res;
-        }
+
+        rtc = rtc_device_register("max6902",
+                                &spi->dev, &max6902_rtc_ops, THIS_MODULE);
+        if (IS_ERR(rtc))
+                return PTR_ERR(rtc);
 
         return 0;
 }
 
 static int __devexit max6902_remove(struct spi_device *spi)
 {
-        struct max6902 *chip = platform_get_drvdata(spi);
-        struct rtc_device *rtc = chip->rtc;
-
-        if (rtc)
-                rtc_device_unregister(rtc);
-
-        kfree(chip);
+        struct rtc_device *rtc = platform_get_drvdata(spi);
 
+        rtc_device_unregister(rtc);
         return 0;
 }
 
@@ -261,7 +162,6 @@ static struct spi_driver max6902_driver = {
 
 static __init int max6902_init(void)
 {
-        printk("max6902 spi driver\n");
         return spi_register_driver(&max6902_driver);
 }
 module_init(max6902_init);