--- /dev/null
+From bb0e317bfc453877805a12f975490ad38b6413f1 Mon Sep 17 00:00:00 2001
+From: Alexandre Belloni <alexandre.belloni@bootlin.com>
+Date: Wed, 13 Feb 2019 00:21:36 +0100
+Subject: [PATCH] rtc: rv3028: add new driver
+
+upstream commit e6e7376cfd7b3f9b63de3a22792f64d9bfb2ab53.
+
+Add a driver for the MicroCrystal RV-3028. It is a SMT Real-Time Clock
+Module that incorporates an integrated CMOS circuit together with an XTAL.
+It has an i2c interface.
+
+The driver handles date/time, alarms, trickle charging, timestamping,
+frequency offset correction, EEPROM and NVRAM.
+
+Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
+---
+ Documentation/devicetree/bindings/rtc/rtc.txt | 69 ++
+ drivers/rtc/Kconfig | 9 +
+ drivers/rtc/Makefile | 1 +
+ drivers/rtc/rtc-rv3028.c | 733 ++++++++++++++++++
+ 4 files changed, 812 insertions(+)
+ create mode 100644 Documentation/devicetree/bindings/rtc/rtc.txt
+ create mode 100644 drivers/rtc/rtc-rv3028.c
+
+--- /dev/null
++++ b/Documentation/devicetree/bindings/rtc/rtc.txt
+@@ -0,0 +1,69 @@
++Generic device tree bindings for Real Time Clock devices
++========================================================
++
++This document describes generic bindings which can be used to describe Real Time
++Clock devices in a device tree.
++
++Required properties
++-------------------
++
++- compatible : name of RTC device following generic names recommended practice.
++
++For other required properties e.g. to describe register sets,
++clocks, etc. check the binding documentation of the specific driver.
++
++Optional properties
++-------------------
++
++- start-year : if provided, the default hardware range supported by the RTC is
++ shifted so the first usable year is the specified one.
++
++The following properties may not be supported by all drivers. However, if a
++driver wants to support one of the below features, it should adapt the bindings
++below.
++- trickle-resistor-ohms : Selected resistor for trickle charger. Should be given
++ if trickle charger should be enabled
++- trickle-diode-disable : Do not use internal trickle charger diode Should be
++ given if internal trickle charger diode should be
++ disabled
++- wakeup-source : Enables wake up of host system on alarm
++- quartz-load-femtofarads : The capacitive load of the quartz(x-tal),
++ expressed in femto Farad (fF).
++ The default value shall be listed (if optional),
++ and likewise all valid values.
++
++Trivial RTCs
++------------
++
++This is a list of trivial RTC devices that have simple device tree
++bindings, consisting only of a compatible field, an address and
++possibly an interrupt line.
++
++
++Compatible Vendor / Chip
++========== =============
++abracon,abb5zes3 AB-RTCMC-32.768kHz-B5ZE-S3: Real Time Clock/Calendar Module with I2C Interface
++dallas,ds1374 I2C, 32-Bit Binary Counter Watchdog RTC with Trickle Charger and Reset Input/Output
++dallas,ds1672 Dallas DS1672 Real-time Clock
++dallas,ds3232 Extremely Accurate I²C RTC with Integrated Crystal and SRAM
++epson,rx8010 I2C-BUS INTERFACE REAL TIME CLOCK MODULE
++epson,rx8581 I2C-BUS INTERFACE REAL TIME CLOCK MODULE
++emmicro,em3027 EM Microelectronic EM3027 Real-time Clock
++isil,isl1208 Intersil ISL1208 Low Power RTC with Battery Backed SRAM
++isil,isl1218 Intersil ISL1218 Low Power RTC with Battery Backed SRAM
++isil,isl12022 Intersil ISL12022 Real-time Clock
++microcrystal,rv3028 Real Time Clock Module with I2C-Bus
++microcrystal,rv3029 Real Time Clock Module with I2C-Bus
++microcrystal,rv8523 Real Time Clock
++nxp,pcf2127 Real-time clock
++nxp,pcf2129 Real-time clock
++nxp,pcf8563 Real-time clock/calendar
++pericom,pt7c4338 Real-time Clock Module
++ricoh,r2025sd I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC
++ricoh,r2221tl I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC
++ricoh,rs5c372a I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC
++ricoh,rs5c372b I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC
++ricoh,rv5c386 I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC
++ricoh,rv5c387a I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC
++sii,s35390a 2-wire CMOS real-time clock
++whwave,sd3078 I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC
+--- a/drivers/rtc/Kconfig
++++ b/drivers/rtc/Kconfig
+@@ -625,6 +625,15 @@ config RTC_DRV_EM3027
+ This driver can also be built as a module. If so, the module
+ will be called rtc-em3027.
+
++config RTC_DRV_RV3028
++ tristate "Micro Crystal RV3028"
++ help
++ If you say yes here you get support for the Micro Crystal
++ RV3028.
++
++ This driver can also be built as a module. If so, the module
++ will be called rtc-rv3028.
++
+ config RTC_DRV_RV8803
+ tristate "Micro Crystal RV8803, Epson RX8900"
+ help
+--- a/drivers/rtc/Makefile
++++ b/drivers/rtc/Makefile
+@@ -136,6 +136,7 @@ obj-$(CONFIG_RTC_DRV_RS5C313) += rtc-rs5
+ obj-$(CONFIG_RTC_DRV_RS5C348) += rtc-rs5c348.o
+ obj-$(CONFIG_RTC_DRV_RS5C372) += rtc-rs5c372.o
+ obj-$(CONFIG_RTC_DRV_RTD119X) += rtc-rtd119x.o
++obj-$(CONFIG_RTC_DRV_RV3028) += rtc-rv3028.o
+ obj-$(CONFIG_RTC_DRV_RV3029C2) += rtc-rv3029c2.o
+ obj-$(CONFIG_RTC_DRV_RV8803) += rtc-rv8803.o
+ obj-$(CONFIG_RTC_DRV_RX4581) += rtc-rx4581.o
+--- /dev/null
++++ b/drivers/rtc/rtc-rv3028.c
+@@ -0,0 +1,733 @@
++// SPDX-License-Identifier: GPL-2.0
++/*
++ * RTC driver for the Micro Crystal RV3028
++ *
++ * Copyright (C) 2019 Micro Crystal SA
++ *
++ * Alexandre Belloni <alexandre.belloni@bootlin.com>
++ *
++ */
++
++#include <linux/bcd.h>
++#include <linux/bitops.h>
++#include <linux/i2c.h>
++#include <linux/interrupt.h>
++#include <linux/kernel.h>
++#include <linux/log2.h>
++#include <linux/module.h>
++#include <linux/of_device.h>
++#include <linux/regmap.h>
++#include <linux/rtc.h>
++#include "rtc-core.h"
++
++#define RV3028_SEC 0x00
++#define RV3028_MIN 0x01
++#define RV3028_HOUR 0x02
++#define RV3028_WDAY 0x03
++#define RV3028_DAY 0x04
++#define RV3028_MONTH 0x05
++#define RV3028_YEAR 0x06
++#define RV3028_ALARM_MIN 0x07
++#define RV3028_ALARM_HOUR 0x08
++#define RV3028_ALARM_DAY 0x09
++#define RV3028_STATUS 0x0E
++#define RV3028_CTRL1 0x0F
++#define RV3028_CTRL2 0x10
++#define RV3028_EVT_CTRL 0x13
++#define RV3028_TS_COUNT 0x14
++#define RV3028_TS_SEC 0x15
++#define RV3028_RAM1 0x1F
++#define RV3028_EEPROM_ADDR 0x25
++#define RV3028_EEPROM_DATA 0x26
++#define RV3028_EEPROM_CMD 0x27
++#define RV3028_CLKOUT 0x35
++#define RV3028_OFFSET 0x36
++#define RV3028_BACKUP 0x37
++
++#define RV3028_STATUS_PORF BIT(0)
++#define RV3028_STATUS_EVF BIT(1)
++#define RV3028_STATUS_AF BIT(2)
++#define RV3028_STATUS_TF BIT(3)
++#define RV3028_STATUS_UF BIT(4)
++#define RV3028_STATUS_BSF BIT(5)
++#define RV3028_STATUS_CLKF BIT(6)
++#define RV3028_STATUS_EEBUSY BIT(7)
++
++#define RV3028_CTRL1_EERD BIT(3)
++#define RV3028_CTRL1_WADA BIT(5)
++
++#define RV3028_CTRL2_RESET BIT(0)
++#define RV3028_CTRL2_12_24 BIT(1)
++#define RV3028_CTRL2_EIE BIT(2)
++#define RV3028_CTRL2_AIE BIT(3)
++#define RV3028_CTRL2_TIE BIT(4)
++#define RV3028_CTRL2_UIE BIT(5)
++#define RV3028_CTRL2_TSE BIT(7)
++
++#define RV3028_EVT_CTRL_TSR BIT(2)
++
++#define RV3028_EEPROM_CMD_WRITE 0x21
++#define RV3028_EEPROM_CMD_READ 0x22
++
++#define RV3028_EEBUSY_POLL 10000
++#define RV3028_EEBUSY_TIMEOUT 100000
++
++#define RV3028_BACKUP_TCE BIT(5)
++#define RV3028_BACKUP_TCR_MASK GENMASK(1,0)
++
++#define OFFSET_STEP_PPT 953674
++
++enum rv3028_type {
++ rv_3028,
++};
++
++struct rv3028_data {
++ struct regmap *regmap;
++ struct rtc_device *rtc;
++ enum rv3028_type type;
++};
++
++static u16 rv3028_trickle_resistors[] = {1000, 3000, 6000, 11000};
++
++static ssize_t timestamp0_store(struct device *dev,
++ struct device_attribute *attr,
++ const char *buf, size_t count)
++{
++ struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
++
++ regmap_update_bits(rv3028->regmap, RV3028_EVT_CTRL, RV3028_EVT_CTRL_TSR,
++ RV3028_EVT_CTRL_TSR);
++
++ return count;
++};
++
++static ssize_t timestamp0_show(struct device *dev,
++ struct device_attribute *attr, char *buf)
++{
++ struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
++ struct rtc_time tm;
++ int ret, count;
++ u8 date[6];
++
++ ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count);
++ if (ret)
++ return ret;
++
++ if (!count)
++ return 0;
++
++ ret = regmap_bulk_read(rv3028->regmap, RV3028_TS_SEC, date,
++ sizeof(date));
++ if (ret)
++ return ret;
++
++ tm.tm_sec = bcd2bin(date[0]);
++ tm.tm_min = bcd2bin(date[1]);
++ tm.tm_hour = bcd2bin(date[2]);
++ tm.tm_mday = bcd2bin(date[3]);
++ tm.tm_mon = bcd2bin(date[4]) - 1;
++ tm.tm_year = bcd2bin(date[5]) + 100;
++
++ ret = rtc_valid_tm(&tm);
++ if (ret)
++ return ret;
++
++ return sprintf(buf, "%llu\n",
++ (unsigned long long)rtc_tm_to_time64(&tm));
++};
++
++static DEVICE_ATTR_RW(timestamp0);
++
++static ssize_t timestamp0_count_show(struct device *dev,
++ struct device_attribute *attr, char *buf)
++{
++ struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
++ int ret, count;
++
++ ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count);
++ if (ret)
++ return ret;
++
++ return sprintf(buf, "%u\n", count);
++};
++
++static DEVICE_ATTR_RO(timestamp0_count);
++
++static struct attribute *rv3028_attrs[] = {
++ &dev_attr_timestamp0.attr,
++ &dev_attr_timestamp0_count.attr,
++ NULL
++};
++
++static const struct attribute_group rv3028_attr_group = {
++ .attrs = rv3028_attrs,
++};
++
++static irqreturn_t rv3028_handle_irq(int irq, void *dev_id)
++{
++ struct rv3028_data *rv3028 = dev_id;
++ unsigned long events = 0;
++ u32 status = 0, ctrl = 0;
++
++ if (regmap_read(rv3028->regmap, RV3028_STATUS, &status) < 0 ||
++ status == 0) {
++ return IRQ_NONE;
++ }
++
++ if (status & RV3028_STATUS_PORF)
++ dev_warn(&rv3028->rtc->dev, "Voltage low, data loss detected.\n");
++
++ if (status & RV3028_STATUS_TF) {
++ status |= RV3028_STATUS_TF;
++ ctrl |= RV3028_CTRL2_TIE;
++ events |= RTC_PF;
++ }
++
++ if (status & RV3028_STATUS_AF) {
++ status |= RV3028_STATUS_AF;
++ ctrl |= RV3028_CTRL2_AIE;
++ events |= RTC_AF;
++ }
++
++ if (status & RV3028_STATUS_UF) {
++ status |= RV3028_STATUS_UF;
++ ctrl |= RV3028_CTRL2_UIE;
++ events |= RTC_UF;
++ }
++
++ if (events) {
++ rtc_update_irq(rv3028->rtc, 1, events);
++ regmap_update_bits(rv3028->regmap, RV3028_STATUS, status, 0);
++ regmap_update_bits(rv3028->regmap, RV3028_CTRL2, ctrl, 0);
++ }
++
++ if (status & RV3028_STATUS_EVF) {
++ sysfs_notify(&rv3028->rtc->dev.kobj, NULL,
++ dev_attr_timestamp0.attr.name);
++ dev_warn(&rv3028->rtc->dev, "event detected");
++ }
++
++ return IRQ_HANDLED;
++}
++
++static int rv3028_get_time(struct device *dev, struct rtc_time *tm)
++{
++ struct rv3028_data *rv3028 = dev_get_drvdata(dev);
++ u8 date[7];
++ int ret, status;
++
++ ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
++ if (ret < 0)
++ return ret;
++
++ if (status & RV3028_STATUS_PORF) {
++ dev_warn(dev, "Voltage low, data is invalid.\n");
++ return -EINVAL;
++ }
++
++ ret = regmap_bulk_read(rv3028->regmap, RV3028_SEC, date, sizeof(date));
++ if (ret)
++ return ret;
++
++ tm->tm_sec = bcd2bin(date[RV3028_SEC] & 0x7f);
++ tm->tm_min = bcd2bin(date[RV3028_MIN] & 0x7f);
++ tm->tm_hour = bcd2bin(date[RV3028_HOUR] & 0x3f);
++ tm->tm_wday = ilog2(date[RV3028_WDAY] & 0x7f);
++ tm->tm_mday = bcd2bin(date[RV3028_DAY] & 0x3f);
++ tm->tm_mon = bcd2bin(date[RV3028_MONTH] & 0x1f) - 1;
++ tm->tm_year = bcd2bin(date[RV3028_YEAR]) + 100;
++
++ return 0;
++}
++
++static int rv3028_set_time(struct device *dev, struct rtc_time *tm)
++{
++ struct rv3028_data *rv3028 = dev_get_drvdata(dev);
++ u8 date[7];
++ int ret;
++
++ date[RV3028_SEC] = bin2bcd(tm->tm_sec);
++ date[RV3028_MIN] = bin2bcd(tm->tm_min);
++ date[RV3028_HOUR] = bin2bcd(tm->tm_hour);
++ date[RV3028_WDAY] = 1 << (tm->tm_wday);
++ date[RV3028_DAY] = bin2bcd(tm->tm_mday);
++ date[RV3028_MONTH] = bin2bcd(tm->tm_mon + 1);
++ date[RV3028_YEAR] = bin2bcd(tm->tm_year - 100);
++
++ /*
++ * Writing to the Seconds register has the same effect as setting RESET
++ * bit to 1
++ */
++ ret = regmap_bulk_write(rv3028->regmap, RV3028_SEC, date,
++ sizeof(date));
++ if (ret)
++ return ret;
++
++ ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
++ RV3028_STATUS_PORF, 0);
++
++ return ret;
++}
++
++static int rv3028_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
++{
++ struct rv3028_data *rv3028 = dev_get_drvdata(dev);
++ u8 alarmvals[3];
++ int status, ctrl, ret;
++
++ ret = regmap_bulk_read(rv3028->regmap, RV3028_ALARM_MIN, alarmvals,
++ sizeof(alarmvals));
++ if (ret)
++ return ret;
++
++ ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
++ if (ret < 0)
++ return ret;
++
++ ret = regmap_read(rv3028->regmap, RV3028_CTRL2, &ctrl);
++ if (ret < 0)
++ return ret;
++
++ alrm->time.tm_sec = 0;
++ alrm->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
++ alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
++ alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
++
++ alrm->enabled = !!(ctrl & RV3028_CTRL2_AIE);
++ alrm->pending = (status & RV3028_STATUS_AF) && alrm->enabled;
++
++ return 0;
++}
++
++static int rv3028_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
++{
++ struct rv3028_data *rv3028 = dev_get_drvdata(dev);
++ u8 alarmvals[3];
++ u8 ctrl = 0;
++ int ret;
++
++ /* The alarm has no seconds, round up to nearest minute */
++ if (alrm->time.tm_sec) {
++ time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
++
++ alarm_time += 60 - alrm->time.tm_sec;
++ rtc_time64_to_tm(alarm_time, &alrm->time);
++ }
++
++ ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
++ RV3028_CTRL2_AIE | RV3028_CTRL2_UIE, 0);
++ if (ret)
++ return ret;
++
++ alarmvals[0] = bin2bcd(alrm->time.tm_min);
++ alarmvals[1] = bin2bcd(alrm->time.tm_hour);
++ alarmvals[2] = bin2bcd(alrm->time.tm_mday);
++
++ ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
++ RV3028_STATUS_AF, 0);
++ if (ret)
++ return ret;
++
++ ret = regmap_bulk_write(rv3028->regmap, RV3028_ALARM_MIN, alarmvals,
++ sizeof(alarmvals));
++ if (ret)
++ return ret;
++
++ if (alrm->enabled) {
++ if (rv3028->rtc->uie_rtctimer.enabled)
++ ctrl |= RV3028_CTRL2_UIE;
++ if (rv3028->rtc->aie_timer.enabled)
++ ctrl |= RV3028_CTRL2_AIE;
++ }
++
++ ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
++ RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl);
++
++ return ret;
++}
++
++static int rv3028_alarm_irq_enable(struct device *dev, unsigned int enabled)
++{
++ struct rv3028_data *rv3028 = dev_get_drvdata(dev);
++ int ctrl = 0, ret;
++
++ if (enabled) {
++ if (rv3028->rtc->uie_rtctimer.enabled)
++ ctrl |= RV3028_CTRL2_UIE;
++ if (rv3028->rtc->aie_timer.enabled)
++ ctrl |= RV3028_CTRL2_AIE;
++ }
++
++ ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
++ RV3028_STATUS_AF | RV3028_STATUS_UF, 0);
++ if (ret)
++ return ret;
++
++ ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
++ RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl);
++ if (ret)
++ return ret;
++
++ return 0;
++}
++
++static int rv3028_read_offset(struct device *dev, long *offset)
++{
++ struct rv3028_data *rv3028 = dev_get_drvdata(dev);
++ int ret, value, steps;
++
++ ret = regmap_read(rv3028->regmap, RV3028_OFFSET, &value);
++ if (ret < 0)
++ return ret;
++
++ steps = sign_extend32(value << 1, 8);
++
++ ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &value);
++ if (ret < 0)
++ return ret;
++
++ steps += value >> 7;
++
++ *offset = DIV_ROUND_CLOSEST(steps * OFFSET_STEP_PPT, 1000);
++
++ return 0;
++}
++
++static int rv3028_set_offset(struct device *dev, long offset)
++{
++ struct rv3028_data *rv3028 = dev_get_drvdata(dev);
++ int ret;
++
++ offset = clamp(offset, -244141L, 243187L) * 1000;
++ offset = DIV_ROUND_CLOSEST(offset, OFFSET_STEP_PPT);
++
++ ret = regmap_write(rv3028->regmap, RV3028_OFFSET, offset >> 1);
++ if (ret < 0)
++ return ret;
++
++ return regmap_update_bits(rv3028->regmap, RV3028_BACKUP, BIT(7),
++ offset << 7);
++}
++
++static int rv3028_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
++{
++ struct rv3028_data *rv3028 = dev_get_drvdata(dev);
++ int status, ret = 0;
++
++ switch (cmd) {
++ case RTC_VL_READ:
++ ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
++ if (ret < 0)
++ return ret;
++
++ if (status & RV3028_STATUS_PORF)
++ dev_warn(&rv3028->rtc->dev, "Voltage low, data loss detected.\n");
++
++ status &= RV3028_STATUS_PORF;
++
++ if (copy_to_user((void __user *)arg, &status, sizeof(int)))
++ return -EFAULT;
++
++ return 0;
++
++ case RTC_VL_CLR:
++ ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
++ RV3028_STATUS_PORF, 0);
++
++ return ret;
++
++ default:
++ return -ENOIOCTLCMD;
++ }
++}
++
++static int rv3028_nvram_write(void *priv, unsigned int offset, void *val,
++ size_t bytes)
++{
++ return regmap_bulk_write(priv, RV3028_RAM1 + offset, val, bytes);
++}
++
++static int rv3028_nvram_read(void *priv, unsigned int offset, void *val,
++ size_t bytes)
++{
++ return regmap_bulk_read(priv, RV3028_RAM1 + offset, val, bytes);
++}
++
++static int rv3028_eeprom_write(void *priv, unsigned int offset, void *val,
++ size_t bytes)
++{
++ u32 status, ctrl1;
++ int i, ret, err;
++ u8 *buf = val;
++
++ ret = regmap_read(priv, RV3028_CTRL1, &ctrl1);
++ if (ret)
++ return ret;
++
++ if (!(ctrl1 & RV3028_CTRL1_EERD)) {
++ ret = regmap_update_bits(priv, RV3028_CTRL1,
++ RV3028_CTRL1_EERD, RV3028_CTRL1_EERD);
++ if (ret)
++ return ret;
++
++ ret = regmap_read_poll_timeout(priv, RV3028_STATUS, status,
++ !(status & RV3028_STATUS_EEBUSY),
++ RV3028_EEBUSY_POLL,
++ RV3028_EEBUSY_TIMEOUT);
++ if (ret)
++ goto restore_eerd;
++ }
++
++ for (i = 0; i < bytes; i++) {
++ ret = regmap_write(priv, RV3028_EEPROM_ADDR, offset + i);
++ if (ret)
++ goto restore_eerd;
++
++ ret = regmap_write(priv, RV3028_EEPROM_DATA, buf[i]);
++ if (ret)
++ goto restore_eerd;
++
++ ret = regmap_write(priv, RV3028_EEPROM_CMD, 0x0);
++ if (ret)
++ goto restore_eerd;
++
++ ret = regmap_write(priv, RV3028_EEPROM_CMD,
++ RV3028_EEPROM_CMD_WRITE);
++ if (ret)
++ goto restore_eerd;
++
++ usleep_range(RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
++
++ ret = regmap_read_poll_timeout(priv, RV3028_STATUS, status,
++ !(status & RV3028_STATUS_EEBUSY),
++ RV3028_EEBUSY_POLL,
++ RV3028_EEBUSY_TIMEOUT);
++ if (ret)
++ goto restore_eerd;
++ }
++
++restore_eerd:
++ if (!(ctrl1 & RV3028_CTRL1_EERD))
++ {
++ err = regmap_update_bits(priv, RV3028_CTRL1, RV3028_CTRL1_EERD,
++ 0);
++ if (err && !ret)
++ ret = err;
++ }
++
++ return ret;
++}
++
++static int rv3028_eeprom_read(void *priv, unsigned int offset, void *val,
++ size_t bytes)
++{
++ u32 status, ctrl1, data;
++ int i, ret, err;
++ u8 *buf = val;
++
++ ret = regmap_read(priv, RV3028_CTRL1, &ctrl1);
++ if (ret)
++ return ret;
++
++ if (!(ctrl1 & RV3028_CTRL1_EERD)) {
++ ret = regmap_update_bits(priv, RV3028_CTRL1,
++ RV3028_CTRL1_EERD, RV3028_CTRL1_EERD);
++ if (ret)
++ return ret;
++
++ ret = regmap_read_poll_timeout(priv, RV3028_STATUS, status,
++ !(status & RV3028_STATUS_EEBUSY),
++ RV3028_EEBUSY_POLL,
++ RV3028_EEBUSY_TIMEOUT);
++ if (ret)
++ goto restore_eerd;
++ }
++
++ for (i = 0; i < bytes; i++) {
++ ret = regmap_write(priv, RV3028_EEPROM_ADDR, offset + i);
++ if (ret)
++ goto restore_eerd;
++
++ ret = regmap_write(priv, RV3028_EEPROM_CMD, 0x0);
++ if (ret)
++ goto restore_eerd;
++
++ ret = regmap_write(priv, RV3028_EEPROM_CMD,
++ RV3028_EEPROM_CMD_READ);
++ if (ret)
++ goto restore_eerd;
++
++ ret = regmap_read_poll_timeout(priv, RV3028_STATUS, status,
++ !(status & RV3028_STATUS_EEBUSY),
++ RV3028_EEBUSY_POLL,
++ RV3028_EEBUSY_TIMEOUT);
++ if (ret)
++ goto restore_eerd;
++
++ ret = regmap_read(priv, RV3028_EEPROM_DATA, &data);
++ if (ret)
++ goto restore_eerd;
++ buf[i] = data;
++ }
++
++restore_eerd:
++ if (!(ctrl1 & RV3028_CTRL1_EERD))
++ {
++ err = regmap_update_bits(priv, RV3028_CTRL1, RV3028_CTRL1_EERD,
++ 0);
++ if (err && !ret)
++ ret = err;
++ }
++
++ return ret;
++}
++
++static struct rtc_class_ops rv3028_rtc_ops = {
++ .read_time = rv3028_get_time,
++ .set_time = rv3028_set_time,
++ .read_offset = rv3028_read_offset,
++ .set_offset = rv3028_set_offset,
++ .ioctl = rv3028_ioctl,
++};
++
++static const struct regmap_config regmap_config = {
++ .reg_bits = 8,
++ .val_bits = 8,
++ .max_register = 0x37,
++};
++
++static int rv3028_probe(struct i2c_client *client)
++{
++ struct rv3028_data *rv3028;
++ int ret, status;
++ u32 ohms;
++ struct nvmem_config nvmem_cfg = {
++ .name = "rv3028_nvram",
++ .word_size = 1,
++ .stride = 1,
++ .size = 2,
++ .type = NVMEM_TYPE_BATTERY_BACKED,
++ .reg_read = rv3028_nvram_read,
++ .reg_write = rv3028_nvram_write,
++ };
++ struct nvmem_config eeprom_cfg = {
++ .name = "rv3028_eeprom",
++ .word_size = 1,
++ .stride = 1,
++ .size = 43,
++ .type = NVMEM_TYPE_EEPROM,
++ .reg_read = rv3028_eeprom_read,
++ .reg_write = rv3028_eeprom_write,
++ };
++
++ rv3028 = devm_kzalloc(&client->dev, sizeof(struct rv3028_data),
++ GFP_KERNEL);
++ if (!rv3028)
++ return -ENOMEM;
++
++ rv3028->regmap = devm_regmap_init_i2c(client, ®map_config);
++
++ i2c_set_clientdata(client, rv3028);
++
++ ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
++ if (ret < 0)
++ return ret;
++
++ if (status & RV3028_STATUS_PORF)
++ dev_warn(&client->dev, "Voltage low, data loss detected.\n");
++
++ if (status & RV3028_STATUS_AF)
++ dev_warn(&client->dev, "An alarm may have been missed.\n");
++
++ rv3028->rtc = devm_rtc_allocate_device(&client->dev);
++ if (IS_ERR(rv3028->rtc)) {
++ return PTR_ERR(rv3028->rtc);
++ }
++
++ if (client->irq > 0) {
++ ret = devm_request_threaded_irq(&client->dev, client->irq,
++ NULL, rv3028_handle_irq,
++ IRQF_TRIGGER_LOW | IRQF_ONESHOT,
++ "rv3028", rv3028);
++ if (ret) {
++ dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
++ client->irq = 0;
++ } else {
++ rv3028_rtc_ops.read_alarm = rv3028_get_alarm;
++ rv3028_rtc_ops.set_alarm = rv3028_set_alarm;
++ rv3028_rtc_ops.alarm_irq_enable = rv3028_alarm_irq_enable;
++ }
++ }
++
++ ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL1,
++ RV3028_CTRL1_WADA, RV3028_CTRL1_WADA);
++ if (ret)
++ return ret;
++
++ /* setup timestamping */
++ ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
++ RV3028_CTRL2_EIE | RV3028_CTRL2_TSE,
++ RV3028_CTRL2_EIE | RV3028_CTRL2_TSE);
++ if (ret)
++ return ret;
++
++ /* setup trickle charger */
++ if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms",
++ &ohms)) {
++ int i;
++
++ for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++)
++ if (ohms == rv3028_trickle_resistors[i])
++ break;
++
++ if (i < ARRAY_SIZE(rv3028_trickle_resistors)) {
++ ret = regmap_update_bits(rv3028->regmap, RV3028_BACKUP,
++ RV3028_BACKUP_TCE |
++ RV3028_BACKUP_TCR_MASK,
++ RV3028_BACKUP_TCE | i);
++ if (ret)
++ return ret;
++ } else {
++ dev_warn(&client->dev, "invalid trickle resistor value\n");
++ }
++ }
++
++ ret = rtc_add_group(rv3028->rtc, &rv3028_attr_group);
++ if (ret)
++ return ret;
++
++ rv3028->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
++ rv3028->rtc->range_max = RTC_TIMESTAMP_END_2099;
++ rv3028->rtc->ops = &rv3028_rtc_ops;
++ ret = rtc_register_device(rv3028->rtc);
++ if (ret)
++ return ret;
++
++ nvmem_cfg.priv = rv3028->regmap;
++ rtc_nvmem_register(rv3028->rtc, &nvmem_cfg);
++ eeprom_cfg.priv = rv3028->regmap;
++ rtc_nvmem_register(rv3028->rtc, &eeprom_cfg);
++
++ rv3028->rtc->max_user_freq = 1;
++
++ return 0;
++}
++
++static const struct of_device_id rv3028_of_match[] = {
++ { .compatible = "microcrystal,rv3028", },
++ { }
++};
++MODULE_DEVICE_TABLE(of, rv3028_of_match);
++
++static struct i2c_driver rv3028_driver = {
++ .driver = {
++ .name = "rtc-rv3028",
++ .of_match_table = of_match_ptr(rv3028_of_match),
++ },
++ .probe_new = rv3028_probe,
++};
++module_i2c_driver(rv3028_driver);
++
++MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
++MODULE_DESCRIPTION("Micro Crystal RV3028 RTC driver");
++MODULE_LICENSE("GPL v2");
projects / openwrt / openwrt.git / blobdiff