rtc: add rtc-abx80x, a driver for the Abracon AB x80x i2c rtc
This is a basic driver for the ultra-low-power Abracon AB x80x series of RTC chips. It supports in particular, the supersets AB0805 and AB1805. It allows reading and writing the time, and enables the supercapacitor/ battery charger. [arnd@arndb.de: abx805 depends on i2c] [alexandre.belloni@free-electrons.com: renam buffer from date to buf in abx80x_rtc_read_time()] Signed-off-by: Philippe De Muyter <phdm@macqel.be> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Philippe De Muyter
Linus Torvalds
parent
c71f1e05e6
commit
4d61ff6b99
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@ -164,6 +164,16 @@ config RTC_DRV_ABB5ZES3
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This driver can also be built as a module. If so, the module
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will be called rtc-ab-b5ze-s3.
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config RTC_DRV_ABX80X
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tristate "Abracon ABx80x"
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help
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If you say yes here you get support for Abracon AB080X and AB180X
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families of ultra-low-power battery- and capacitor-backed real-time
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clock chips.
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This driver can also be built as a module. If so, the module
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will be called rtc-abx80x.
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config RTC_DRV_AS3722
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tristate "ams AS3722 RTC driver"
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depends on MFD_AS3722
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@ -25,6 +25,7 @@ obj-$(CONFIG_RTC_DRV_88PM80X) += rtc-88pm80x.o
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obj-$(CONFIG_RTC_DRV_AB3100) += rtc-ab3100.o
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obj-$(CONFIG_RTC_DRV_AB8500) += rtc-ab8500.o
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obj-$(CONFIG_RTC_DRV_ABB5ZES3) += rtc-ab-b5ze-s3.o
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obj-$(CONFIG_RTC_DRV_ABX80X) += rtc-abx80x.o
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obj-$(CONFIG_RTC_DRV_ARMADA38X) += rtc-armada38x.o
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obj-$(CONFIG_RTC_DRV_AS3722) += rtc-as3722.o
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obj-$(CONFIG_RTC_DRV_AT32AP700X)+= rtc-at32ap700x.o
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@ -0,0 +1,307 @@
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/*
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* A driver for the I2C members of the Abracon AB x8xx RTC family,
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* and compatible: AB 1805 and AB 0805
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*
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* Copyright 2014-2015 Macq S.A.
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*
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* Author: Philippe De Muyter <phdm@macqel.be>
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* Author: Alexandre Belloni <alexandre.belloni@free-electrons.com>
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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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*/
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#include <linux/bcd.h>
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#include <linux/i2c.h>
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#include <linux/module.h>
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#include <linux/rtc.h>
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#define ABX8XX_REG_HTH 0x00
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#define ABX8XX_REG_SC 0x01
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#define ABX8XX_REG_MN 0x02
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#define ABX8XX_REG_HR 0x03
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#define ABX8XX_REG_DA 0x04
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#define ABX8XX_REG_MO 0x05
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#define ABX8XX_REG_YR 0x06
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#define ABX8XX_REG_WD 0x07
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#define ABX8XX_REG_CTRL1 0x10
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#define ABX8XX_CTRL_WRITE BIT(1)
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#define ABX8XX_CTRL_12_24 BIT(6)
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#define ABX8XX_REG_CFG_KEY 0x1f
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#define ABX8XX_CFG_KEY_MISC 0x9d
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#define ABX8XX_REG_ID0 0x28
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#define ABX8XX_REG_TRICKLE 0x20
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#define ABX8XX_TRICKLE_CHARGE_ENABLE 0xa0
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#define ABX8XX_TRICKLE_STANDARD_DIODE 0x8
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#define ABX8XX_TRICKLE_SCHOTTKY_DIODE 0x4
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static u8 trickle_resistors[] = {0, 3, 6, 11};
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enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
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AB1801, AB1803, AB1804, AB1805, ABX80X};
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struct abx80x_cap {
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u16 pn;
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bool has_tc;
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};
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static struct abx80x_cap abx80x_caps[] = {
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[AB0801] = {.pn = 0x0801},
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[AB0803] = {.pn = 0x0803},
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[AB0804] = {.pn = 0x0804, .has_tc = true},
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[AB0805] = {.pn = 0x0805, .has_tc = true},
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[AB1801] = {.pn = 0x1801},
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[AB1803] = {.pn = 0x1803},
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[AB1804] = {.pn = 0x1804, .has_tc = true},
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[AB1805] = {.pn = 0x1805, .has_tc = true},
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[ABX80X] = {.pn = 0}
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};
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static struct i2c_driver abx80x_driver;
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static int abx80x_enable_trickle_charger(struct i2c_client *client,
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u8 trickle_cfg)
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{
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int err;
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/*
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* Write the configuration key register to enable access to the Trickle
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* register
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*/
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err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
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ABX8XX_CFG_KEY_MISC);
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if (err < 0) {
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dev_err(&client->dev, "Unable to write configuration key\n");
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return -EIO;
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}
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err = i2c_smbus_write_byte_data(client, ABX8XX_REG_TRICKLE,
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ABX8XX_TRICKLE_CHARGE_ENABLE |
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trickle_cfg);
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if (err < 0) {
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dev_err(&client->dev, "Unable to write trickle register\n");
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return -EIO;
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}
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return 0;
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}
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static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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struct i2c_client *client = to_i2c_client(dev);
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unsigned char buf[8];
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int err;
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err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH,
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sizeof(buf), buf);
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if (err < 0) {
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dev_err(&client->dev, "Unable to read date\n");
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return -EIO;
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}
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tm->tm_sec = bcd2bin(buf[ABX8XX_REG_SC] & 0x7F);
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tm->tm_min = bcd2bin(buf[ABX8XX_REG_MN] & 0x7F);
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tm->tm_hour = bcd2bin(buf[ABX8XX_REG_HR] & 0x3F);
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tm->tm_wday = buf[ABX8XX_REG_WD] & 0x7;
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tm->tm_mday = bcd2bin(buf[ABX8XX_REG_DA] & 0x3F);
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tm->tm_mon = bcd2bin(buf[ABX8XX_REG_MO] & 0x1F) - 1;
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tm->tm_year = bcd2bin(buf[ABX8XX_REG_YR]) + 100;
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err = rtc_valid_tm(tm);
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if (err < 0)
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dev_err(&client->dev, "retrieved date/time is not valid.\n");
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return err;
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}
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static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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struct i2c_client *client = to_i2c_client(dev);
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unsigned char buf[8];
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int err;
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if (tm->tm_year < 100)
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return -EINVAL;
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buf[ABX8XX_REG_HTH] = 0;
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buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec);
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buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min);
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buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour);
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buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday);
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buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon + 1);
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buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100);
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buf[ABX8XX_REG_WD] = tm->tm_wday;
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err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH,
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sizeof(buf), buf);
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if (err < 0) {
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dev_err(&client->dev, "Unable to write to date registers\n");
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return -EIO;
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}
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return 0;
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}
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static const struct rtc_class_ops abx80x_rtc_ops = {
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.read_time = abx80x_rtc_read_time,
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.set_time = abx80x_rtc_set_time,
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};
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static int abx80x_dt_trickle_cfg(struct device_node *np)
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{
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const char *diode;
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int trickle_cfg = 0;
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int i, ret;
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u32 tmp;
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ret = of_property_read_string(np, "abracon,tc-diode", &diode);
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if (ret)
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return ret;
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if (!strcmp(diode, "standard"))
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trickle_cfg |= ABX8XX_TRICKLE_STANDARD_DIODE;
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else if (!strcmp(diode, "schottky"))
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trickle_cfg |= ABX8XX_TRICKLE_SCHOTTKY_DIODE;
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else
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return -EINVAL;
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ret = of_property_read_u32(np, "abracon,tc-resistor", &tmp);
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if (ret)
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return ret;
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for (i = 0; i < sizeof(trickle_resistors); i++)
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if (trickle_resistors[i] == tmp)
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break;
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if (i == sizeof(trickle_resistors))
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return -EINVAL;
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return (trickle_cfg | i);
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}
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static int abx80x_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct device_node *np = client->dev.of_node;
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struct rtc_device *rtc;
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int i, data, err, trickle_cfg = -EINVAL;
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char buf[7];
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unsigned int part = id->driver_data;
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unsigned int partnumber;
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unsigned int majrev, minrev;
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unsigned int lot;
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unsigned int wafer;
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unsigned int uid;
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
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return -ENODEV;
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err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0,
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sizeof(buf), buf);
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if (err < 0) {
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dev_err(&client->dev, "Unable to read partnumber\n");
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return -EIO;
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}
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partnumber = (buf[0] << 8) | buf[1];
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majrev = buf[2] >> 3;
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minrev = buf[2] & 0x7;
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lot = ((buf[4] & 0x80) << 2) | ((buf[6] & 0x80) << 1) | buf[3];
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uid = ((buf[4] & 0x7f) << 8) | buf[5];
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wafer = (buf[6] & 0x7c) >> 2;
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dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
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partnumber, majrev, minrev, lot, wafer, uid);
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data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1);
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if (data < 0) {
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dev_err(&client->dev, "Unable to read control register\n");
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return -EIO;
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}
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err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1,
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((data & ~ABX8XX_CTRL_12_24) |
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ABX8XX_CTRL_WRITE));
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if (err < 0) {
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dev_err(&client->dev, "Unable to write control register\n");
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return -EIO;
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}
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/* part autodetection */
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if (part == ABX80X) {
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for (i = 0; abx80x_caps[i].pn; i++)
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if (partnumber == abx80x_caps[i].pn)
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break;
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if (abx80x_caps[i].pn == 0) {
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dev_err(&client->dev, "Unknown part: %04x\n",
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partnumber);
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return -EINVAL;
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}
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part = i;
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}
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if (partnumber != abx80x_caps[part].pn) {
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dev_err(&client->dev, "partnumber mismatch %04x != %04x\n",
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partnumber, abx80x_caps[part].pn);
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return -EINVAL;
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}
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if (np && abx80x_caps[part].has_tc)
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trickle_cfg = abx80x_dt_trickle_cfg(np);
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if (trickle_cfg > 0) {
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dev_info(&client->dev, "Enabling trickle charger: %02x\n",
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trickle_cfg);
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abx80x_enable_trickle_charger(client, trickle_cfg);
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}
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rtc = devm_rtc_device_register(&client->dev, abx80x_driver.driver.name,
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&abx80x_rtc_ops, THIS_MODULE);
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if (IS_ERR(rtc))
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return PTR_ERR(rtc);
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i2c_set_clientdata(client, rtc);
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return 0;
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}
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static int abx80x_remove(struct i2c_client *client)
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{
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return 0;
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}
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static const struct i2c_device_id abx80x_id[] = {
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{ "abx80x", ABX80X },
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{ "ab0801", AB0801 },
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{ "ab0803", AB0803 },
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{ "ab0804", AB0804 },
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{ "ab0805", AB0805 },
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{ "ab1801", AB1801 },
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{ "ab1803", AB1803 },
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{ "ab1804", AB1804 },
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{ "ab1805", AB1805 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, abx80x_id);
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static struct i2c_driver abx80x_driver = {
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.driver = {
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.name = "rtc-abx80x",
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},
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.probe = abx80x_probe,
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.remove = abx80x_remove,
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.id_table = abx80x_id,
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};
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module_i2c_driver(abx80x_driver);
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MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
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MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
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MODULE_DESCRIPTION("Abracon ABX80X RTC driver");
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MODULE_LICENSE("GPL v2");
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