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![Alexandre Belloni](/assets/img/avatar_default.png)
The RTC core is always calling rtc_valid_tm after the read_time callback. It is not necessary to call it just before returning from the callback. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
446 lines
10 KiB
C
446 lines
10 KiB
C
/*
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* An I2C and SPI driver for the NXP PCF2127/29 RTC
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* Copyright 2013 Til-Technologies
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*
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* Author: Renaud Cerrato <r.cerrato@til-technologies.fr>
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*
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* based on the other drivers in this same directory.
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*
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* Datasheet: http://cache.nxp.com/documents/data_sheet/PCF2127.pdf
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/i2c.h>
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#include <linux/spi/spi.h>
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#include <linux/bcd.h>
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#include <linux/rtc.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/regmap.h>
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#define PCF2127_REG_CTRL1 (0x00) /* Control Register 1 */
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#define PCF2127_REG_CTRL2 (0x01) /* Control Register 2 */
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#define PCF2127_REG_CTRL3 (0x02) /* Control Register 3 */
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#define PCF2127_REG_CTRL3_BLF BIT(2)
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#define PCF2127_REG_SC (0x03) /* datetime */
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#define PCF2127_REG_MN (0x04)
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#define PCF2127_REG_HR (0x05)
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#define PCF2127_REG_DM (0x06)
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#define PCF2127_REG_DW (0x07)
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#define PCF2127_REG_MO (0x08)
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#define PCF2127_REG_YR (0x09)
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#define PCF2127_OSF BIT(7) /* Oscillator Fail flag */
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struct pcf2127 {
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struct rtc_device *rtc;
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struct regmap *regmap;
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};
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/*
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* In the routines that deal directly with the pcf2127 hardware, we use
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* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
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*/
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static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
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unsigned char buf[10];
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int ret;
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int i;
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for (i = 0; i <= PCF2127_REG_CTRL3; i++) {
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ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL1 + i,
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(unsigned int *)(buf + i));
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if (ret) {
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dev_err(dev, "%s: read error\n", __func__);
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return ret;
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}
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}
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ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_SC,
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(buf + PCF2127_REG_SC),
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ARRAY_SIZE(buf) - PCF2127_REG_SC);
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if (ret) {
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dev_err(dev, "%s: read error\n", __func__);
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return ret;
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}
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if (buf[PCF2127_REG_CTRL3] & PCF2127_REG_CTRL3_BLF)
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dev_info(dev,
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"low voltage detected, check/replace RTC battery.\n");
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if (buf[PCF2127_REG_SC] & PCF2127_OSF) {
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/*
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* no need clear the flag here,
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* it will be cleared once the new date is saved
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*/
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dev_warn(dev,
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"oscillator stop detected, date/time is not reliable\n");
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return -EINVAL;
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}
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dev_dbg(dev,
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"%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, "
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"sec=%02x, min=%02x, hr=%02x, "
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"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
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__func__,
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buf[0], buf[1], buf[2],
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buf[3], buf[4], buf[5],
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buf[6], buf[7], buf[8], buf[9]);
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tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
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tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
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tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */
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tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
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tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
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tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
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tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]);
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if (tm->tm_year < 70)
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tm->tm_year += 100; /* assume we are in 1970...2069 */
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dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
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"mday=%d, mon=%d, year=%d, wday=%d\n",
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__func__,
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tm->tm_sec, tm->tm_min, tm->tm_hour,
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tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
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return 0;
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}
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static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
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unsigned char buf[7];
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int i = 0, err;
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dev_dbg(dev, "%s: secs=%d, mins=%d, hours=%d, "
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"mday=%d, mon=%d, year=%d, wday=%d\n",
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__func__,
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tm->tm_sec, tm->tm_min, tm->tm_hour,
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tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
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/* hours, minutes and seconds */
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buf[i++] = bin2bcd(tm->tm_sec); /* this will also clear OSF flag */
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buf[i++] = bin2bcd(tm->tm_min);
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buf[i++] = bin2bcd(tm->tm_hour);
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buf[i++] = bin2bcd(tm->tm_mday);
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buf[i++] = tm->tm_wday & 0x07;
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/* month, 1 - 12 */
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buf[i++] = bin2bcd(tm->tm_mon + 1);
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/* year */
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buf[i++] = bin2bcd(tm->tm_year % 100);
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/* write register's data */
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err = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_SC, buf, i);
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if (err) {
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dev_err(dev,
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"%s: err=%d", __func__, err);
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return err;
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}
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return 0;
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}
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#ifdef CONFIG_RTC_INTF_DEV
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static int pcf2127_rtc_ioctl(struct device *dev,
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unsigned int cmd, unsigned long arg)
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{
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struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
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int touser;
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int ret;
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switch (cmd) {
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case RTC_VL_READ:
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ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL3, &touser);
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if (ret)
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return ret;
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touser = touser & PCF2127_REG_CTRL3_BLF ? 1 : 0;
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if (copy_to_user((void __user *)arg, &touser, sizeof(int)))
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return -EFAULT;
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return 0;
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default:
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return -ENOIOCTLCMD;
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}
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}
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#else
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#define pcf2127_rtc_ioctl NULL
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#endif
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static const struct rtc_class_ops pcf2127_rtc_ops = {
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.ioctl = pcf2127_rtc_ioctl,
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.read_time = pcf2127_rtc_read_time,
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.set_time = pcf2127_rtc_set_time,
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};
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static int pcf2127_probe(struct device *dev, struct regmap *regmap,
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const char *name)
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{
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struct pcf2127 *pcf2127;
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dev_dbg(dev, "%s\n", __func__);
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pcf2127 = devm_kzalloc(dev, sizeof(*pcf2127), GFP_KERNEL);
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if (!pcf2127)
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return -ENOMEM;
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pcf2127->regmap = regmap;
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dev_set_drvdata(dev, pcf2127);
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pcf2127->rtc = devm_rtc_device_register(dev, name, &pcf2127_rtc_ops,
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THIS_MODULE);
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return PTR_ERR_OR_ZERO(pcf2127->rtc);
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}
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#ifdef CONFIG_OF
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static const struct of_device_id pcf2127_of_match[] = {
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{ .compatible = "nxp,pcf2127" },
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{ .compatible = "nxp,pcf2129" },
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{}
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};
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MODULE_DEVICE_TABLE(of, pcf2127_of_match);
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#endif
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#if IS_ENABLED(CONFIG_I2C)
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static int pcf2127_i2c_write(void *context, const void *data, size_t count)
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{
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struct device *dev = context;
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struct i2c_client *client = to_i2c_client(dev);
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int ret;
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ret = i2c_master_send(client, data, count);
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if (ret != count)
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return ret < 0 ? ret : -EIO;
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return 0;
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}
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static int pcf2127_i2c_gather_write(void *context,
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const void *reg, size_t reg_size,
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const void *val, size_t val_size)
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{
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struct device *dev = context;
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struct i2c_client *client = to_i2c_client(dev);
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int ret;
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void *buf;
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if (WARN_ON(reg_size != 1))
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return -EINVAL;
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buf = kmalloc(val_size + 1, GFP_KERNEL);
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if (!buf)
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return -ENOMEM;
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memcpy(buf, reg, 1);
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memcpy(buf + 1, val, val_size);
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ret = i2c_master_send(client, buf, val_size + 1);
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if (ret != val_size + 1)
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return ret < 0 ? ret : -EIO;
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return 0;
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}
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static int pcf2127_i2c_read(void *context, const void *reg, size_t reg_size,
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void *val, size_t val_size)
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{
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struct device *dev = context;
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struct i2c_client *client = to_i2c_client(dev);
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int ret;
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if (WARN_ON(reg_size != 1))
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return -EINVAL;
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ret = i2c_master_send(client, reg, 1);
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if (ret != 1)
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return ret < 0 ? ret : -EIO;
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ret = i2c_master_recv(client, val, val_size);
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if (ret != val_size)
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return ret < 0 ? ret : -EIO;
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return 0;
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}
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/*
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* The reason we need this custom regmap_bus instead of using regmap_init_i2c()
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* is that the STOP condition is required between set register address and
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* read register data when reading from registers.
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*/
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static const struct regmap_bus pcf2127_i2c_regmap = {
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.write = pcf2127_i2c_write,
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.gather_write = pcf2127_i2c_gather_write,
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.read = pcf2127_i2c_read,
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};
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static struct i2c_driver pcf2127_i2c_driver;
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static int pcf2127_i2c_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct regmap *regmap;
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static const struct regmap_config config = {
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.reg_bits = 8,
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.val_bits = 8,
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};
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
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return -ENODEV;
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regmap = devm_regmap_init(&client->dev, &pcf2127_i2c_regmap,
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&client->dev, &config);
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if (IS_ERR(regmap)) {
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dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
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__func__, PTR_ERR(regmap));
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return PTR_ERR(regmap);
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}
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return pcf2127_probe(&client->dev, regmap,
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pcf2127_i2c_driver.driver.name);
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}
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static const struct i2c_device_id pcf2127_i2c_id[] = {
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{ "pcf2127", 0 },
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{ "pcf2129", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, pcf2127_i2c_id);
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static struct i2c_driver pcf2127_i2c_driver = {
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.driver = {
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.name = "rtc-pcf2127-i2c",
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.of_match_table = of_match_ptr(pcf2127_of_match),
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},
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.probe = pcf2127_i2c_probe,
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.id_table = pcf2127_i2c_id,
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};
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static int pcf2127_i2c_register_driver(void)
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{
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return i2c_add_driver(&pcf2127_i2c_driver);
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}
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static void pcf2127_i2c_unregister_driver(void)
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{
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i2c_del_driver(&pcf2127_i2c_driver);
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}
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#else
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static int pcf2127_i2c_register_driver(void)
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{
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return 0;
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}
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static void pcf2127_i2c_unregister_driver(void)
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{
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}
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#endif
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#if IS_ENABLED(CONFIG_SPI_MASTER)
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static struct spi_driver pcf2127_spi_driver;
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static int pcf2127_spi_probe(struct spi_device *spi)
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{
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static const struct regmap_config config = {
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.reg_bits = 8,
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.val_bits = 8,
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.read_flag_mask = 0xa0,
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.write_flag_mask = 0x20,
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};
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struct regmap *regmap;
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regmap = devm_regmap_init_spi(spi, &config);
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if (IS_ERR(regmap)) {
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dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
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__func__, PTR_ERR(regmap));
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return PTR_ERR(regmap);
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}
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return pcf2127_probe(&spi->dev, regmap, pcf2127_spi_driver.driver.name);
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}
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static const struct spi_device_id pcf2127_spi_id[] = {
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{ "pcf2127", 0 },
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{ "pcf2129", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(spi, pcf2127_spi_id);
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static struct spi_driver pcf2127_spi_driver = {
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.driver = {
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.name = "rtc-pcf2127-spi",
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.of_match_table = of_match_ptr(pcf2127_of_match),
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},
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.probe = pcf2127_spi_probe,
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.id_table = pcf2127_spi_id,
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};
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static int pcf2127_spi_register_driver(void)
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{
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return spi_register_driver(&pcf2127_spi_driver);
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}
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static void pcf2127_spi_unregister_driver(void)
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{
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spi_unregister_driver(&pcf2127_spi_driver);
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}
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#else
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static int pcf2127_spi_register_driver(void)
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{
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return 0;
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}
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static void pcf2127_spi_unregister_driver(void)
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{
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}
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#endif
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static int __init pcf2127_init(void)
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{
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int ret;
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ret = pcf2127_i2c_register_driver();
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if (ret) {
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pr_err("Failed to register pcf2127 i2c driver: %d\n", ret);
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return ret;
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}
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ret = pcf2127_spi_register_driver();
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if (ret) {
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pr_err("Failed to register pcf2127 spi driver: %d\n", ret);
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pcf2127_i2c_unregister_driver();
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}
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return ret;
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}
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module_init(pcf2127_init)
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static void __exit pcf2127_exit(void)
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{
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pcf2127_spi_unregister_driver();
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pcf2127_i2c_unregister_driver();
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}
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module_exit(pcf2127_exit)
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MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
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MODULE_DESCRIPTION("NXP PCF2127/29 RTC driver");
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MODULE_LICENSE("GPL v2");
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