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rtc: rtc-ds3234 fixes
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- no changelogs in code
- no banners
- use local buffers
- fix probe sequence
- do not init .driver.bus

Signed-off-by: Alessandro Zummo <[email protected]>
Cc: Dennis Aberilla <[email protected]>
Acked-by: David Brownell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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@torvalds
Alessandro Zummo authored and torvalds committed Jan 6, 2009
1 parent a5771c6 commit f600915
Showing 1 changed file with 36 additions and 136 deletions.
172 changes: 36 additions & 136 deletions drivers/rtc/rtc-ds3234.c
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
/* drivers/rtc/rtc-ds3234.c
/* rtc-ds3234.c
*
* Driver for Dallas Semiconductor (DS3234) SPI RTC with Integrated Crystal
* and SRAM.
Expand All @@ -9,13 +9,10 @@
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Changelog:
*
* 07-May-2008: Dennis Aberilla <[email protected]>
* - Created based on the max6902 code. Only implements the
* date/time keeping functions; no SRAM yet.
*/

#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
Expand All @@ -34,16 +31,7 @@
#define DS3234_REG_CONTROL 0x0E
#define DS3234_REG_CONT_STAT 0x0F

#undef DS3234_DEBUG

struct ds3234 {
struct rtc_device *rtc;
u8 buf[8]; /* Burst read: addr + 7 regs */
u8 tx_buf[2];
u8 rx_buf[2];
};

static void ds3234_set_reg(struct device *dev, unsigned char address,
static int ds3234_set_reg(struct device *dev, unsigned char address,
unsigned char data)
{
struct spi_device *spi = to_spi_device(dev);
Expand All @@ -53,107 +41,45 @@ static void ds3234_set_reg(struct device *dev, unsigned char address,
buf[0] = address | 0x80;
buf[1] = data;

spi_write(spi, buf, 2);
return spi_write_then_read(spi, buf, 2, NULL, 0);
}

static int ds3234_get_reg(struct device *dev, unsigned char address,
unsigned char *data)
{
struct spi_device *spi = to_spi_device(dev);
struct ds3234 *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));

/* Address + dummy tx byte */
xfer.len = 2;
xfer.tx_buf = chip->tx_buf;
xfer.rx_buf = chip->rx_buf;

chip->tx_buf[0] = address;
chip->tx_buf[1] = 0xff;

spi_message_add_tail(&xfer, &message);
*data = address & 0x7f;

/* do the i/o */
status = spi_sync(spi, &message);
if (status == 0)
status = message.status;
else
return status;

*data = chip->rx_buf[1];

return status;
return spi_write_then_read(spi, data, 1, data, 1);
}

static int ds3234_get_datetime(struct device *dev, struct rtc_time *dt)
static int ds3234_read_time(struct device *dev, struct rtc_time *dt)
{
int err;
unsigned char buf[8];
struct spi_device *spi = to_spi_device(dev);
struct ds3234 *chip = dev_get_drvdata(dev);
struct spi_message message;
struct spi_transfer xfer;
int status;

/* build the message */
spi_message_init(&message);
memset(&xfer, 0, sizeof(xfer));
xfer.len = 1 + 7; /* Addr + 7 registers */
xfer.tx_buf = chip->buf;
xfer.rx_buf = chip->buf;
chip->buf[0] = 0x00; /* Start address */
spi_message_add_tail(&xfer, &message);

/* do the i/o */
status = spi_sync(spi, &message);
if (status == 0)
status = message.status;
else
return status;

/* Seconds, Minutes, Hours, Day, Date, Month, Year */
dt->tm_sec = bcd2bin(chip->buf[1]);
dt->tm_min = bcd2bin(chip->buf[2]);
dt->tm_hour = bcd2bin(chip->buf[3] & 0x3f);
dt->tm_wday = bcd2bin(chip->buf[4]) - 1; /* 0 = Sun */
dt->tm_mday = bcd2bin(chip->buf[5]);
dt->tm_mon = bcd2bin(chip->buf[6] & 0x1f) - 1; /* 0 = Jan */
dt->tm_year = bcd2bin(chip->buf[7] & 0xff) + 100; /* Assume 20YY */

#ifdef DS3234_DEBUG
dev_dbg(dev, "\n%s : Read RTC values\n", __func__);
dev_dbg(dev, "tm_hour: %i\n", dt->tm_hour);
dev_dbg(dev, "tm_min : %i\n", dt->tm_min);
dev_dbg(dev, "tm_sec : %i\n", dt->tm_sec);
dev_dbg(dev, "tm_wday: %i\n", dt->tm_wday);
dev_dbg(dev, "tm_mday: %i\n", dt->tm_mday);
dev_dbg(dev, "tm_mon : %i\n", dt->tm_mon);
dev_dbg(dev, "tm_year: %i\n", dt->tm_year);
#endif
buf[0] = 0x00; /* Start address */

return 0;
err = spi_write_then_read(spi, buf, 1, buf, 8);
if (err != 0)
return err;

/* Seconds, Minutes, Hours, Day, Date, Month, Year */
dt->tm_sec = bcd2bin(buf[0]);
dt->tm_min = bcd2bin(buf[1]);
dt->tm_hour = bcd2bin(buf[2] & 0x3f);
dt->tm_wday = bcd2bin(buf[3]) - 1; /* 0 = Sun */
dt->tm_mday = bcd2bin(buf[4]);
dt->tm_mon = bcd2bin(buf[5] & 0x1f) - 1; /* 0 = Jan */
dt->tm_year = bcd2bin(buf[6] & 0xff) + 100; /* Assume 20YY */

return rtc_valid_tm(dt);
}

static int ds3234_set_datetime(struct device *dev, struct rtc_time *dt)
static int ds3234_set_time(struct device *dev, struct rtc_time *dt)
{
#ifdef DS3234_DEBUG
dev_dbg(dev, "\n%s : Setting RTC values\n", __func__);
dev_dbg(dev, "tm_sec : %i\n", dt->tm_sec);
dev_dbg(dev, "tm_min : %i\n", dt->tm_min);
dev_dbg(dev, "tm_hour: %i\n", dt->tm_hour);
dev_dbg(dev, "tm_wday: %i\n", dt->tm_wday);
dev_dbg(dev, "tm_mday: %i\n", dt->tm_mday);
dev_dbg(dev, "tm_mon : %i\n", dt->tm_mon);
dev_dbg(dev, "tm_year: %i\n", dt->tm_year);
#endif

ds3234_set_reg(dev, DS3234_REG_SECONDS, bin2bcd(dt->tm_sec));
ds3234_set_reg(dev, DS3234_REG_MINUTES, bin2bcd(dt->tm_min));
ds3234_set_reg(dev, DS3234_REG_HOURS, bin2bcd(dt->tm_hour) & 0x3f);
Expand All @@ -174,16 +100,6 @@ static int ds3234_set_datetime(struct device *dev, struct rtc_time *dt)
return 0;
}

static int ds3234_read_time(struct device *dev, struct rtc_time *tm)
{
return ds3234_get_datetime(dev, tm);
}

static int ds3234_set_time(struct device *dev, struct rtc_time *tm)
{
return ds3234_set_datetime(dev, tm);
}

static const struct rtc_class_ops ds3234_rtc_ops = {
.read_time = ds3234_read_time,
.set_time = ds3234_set_time,
Expand All @@ -193,31 +109,15 @@ static int __devinit ds3234_probe(struct spi_device *spi)
{
struct rtc_device *rtc;
unsigned char tmp;
struct ds3234 *chip;
int res;

rtc = rtc_device_register("ds3234",
&spi->dev, &ds3234_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(struct ds3234), GFP_KERNEL);
if (!chip) {
rtc_device_unregister(rtc);
return -ENOMEM;
}
chip->rtc = rtc;
dev_set_drvdata(&spi->dev, chip);

res = ds3234_get_reg(&spi->dev, DS3234_REG_SECONDS, &tmp);
if (res) {
rtc_device_unregister(rtc);
if (res != 0)
return res;
}

/* Control settings
*
Expand Down Expand Up @@ -246,26 +146,27 @@ static int __devinit ds3234_probe(struct spi_device *spi)
ds3234_get_reg(&spi->dev, DS3234_REG_CONT_STAT, &tmp);
dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp);

rtc = rtc_device_register("ds3234",
&spi->dev, &ds3234_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc))
return PTR_ERR(rtc);

dev_set_drvdata(&spi->dev, rtc);

return 0;
}

static int __devexit ds3234_remove(struct spi_device *spi)
{
struct ds3234 *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;
}

static struct spi_driver ds3234_driver = {
.driver = {
.name = "ds3234",
.bus = &spi_bus_type,
.owner = THIS_MODULE,
},
.probe = ds3234_probe,
Expand All @@ -274,7 +175,6 @@ static struct spi_driver ds3234_driver = {

static __init int ds3234_init(void)
{
printk(KERN_INFO "DS3234 SPI RTC Driver\n");
return spi_register_driver(&ds3234_driver);
}
module_init(ds3234_init);
Expand Down

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