*
* 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>
#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
#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);
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);
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... */
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,
{
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;
}
static __init int max6902_init(void)
{
- printk("max6902 spi driver\n");
return spi_register_driver(&max6902_driver);
}
module_init(max6902_init);
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff