// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2022 Nuvoton Technology Corporation
#include <linux/bcd.h>
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#define NCT3018Y_REG_SC 0x00 /* seconds */
#define NCT3018Y_REG_SCA 0x01 /* alarm */
#define NCT3018Y_REG_MN 0x02
#define NCT3018Y_REG_MNA 0x03 /* alarm */
#define NCT3018Y_REG_HR 0x04
#define NCT3018Y_REG_HRA 0x05 /* alarm */
#define NCT3018Y_REG_DW 0x06
#define NCT3018Y_REG_DM 0x07
#define NCT3018Y_REG_MO 0x08
#define NCT3018Y_REG_YR 0x09
#define NCT3018Y_REG_CTRL 0x0A /* timer control */
#define NCT3018Y_REG_ST 0x0B /* status */
#define NCT3018Y_REG_CLKO 0x0C /* clock out */
#define NCT3018Y_REG_PART 0x21 /* part info */
#define NCT3018Y_BIT_AF BIT(7)
#define NCT3018Y_BIT_ST BIT(7)
#define NCT3018Y_BIT_DM BIT(6)
#define NCT3018Y_BIT_HF BIT(5)
#define NCT3018Y_BIT_DSM BIT(4)
#define NCT3018Y_BIT_AIE BIT(3)
#define NCT3018Y_BIT_OFIE BIT(2)
#define NCT3018Y_BIT_CIE BIT(1)
#define NCT3018Y_BIT_TWO BIT(0)
#define NCT3018Y_REG_BAT_MASK 0x07
#define NCT3018Y_REG_CLKO_F_MASK 0x03 /* frequenc mask */
#define NCT3018Y_REG_CLKO_CKE 0x80 /* clock out enabled */
#define NCT3018Y_REG_PART_NCT3018Y 0x02
struct nct3018y {
struct rtc_device *rtc;
struct i2c_client *client;
int part_num;
#ifdef CONFIG_COMMON_CLK
struct clk_hw clkout_hw;
#endif
};
static int nct3018y_set_alarm_mode(struct i2c_client *client, bool on)
{
int err, flags;
dev_dbg(&client->dev, "%s:on:%d\n", __func__, on);
flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
if (flags < 0) {
dev_dbg(&client->dev,
"Failed to read NCT3018Y_REG_CTRL\n");
return flags;
}
if (on)
flags |= NCT3018Y_BIT_AIE;
else
flags &= ~NCT3018Y_BIT_AIE;
flags |= NCT3018Y_BIT_CIE;
err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags);
if (err < 0) {
dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL\n");
return err;
}
flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_ST);
if (flags < 0) {
dev_dbg(&client->dev,
"Failed to read NCT3018Y_REG_ST\n");
return flags;
}
flags &= ~(NCT3018Y_BIT_AF);
err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_ST, flags);
if (err < 0) {
dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_ST\n");
return err;
}
return 0;
}
static int nct3018y_get_alarm_mode(struct i2c_client *client, unsigned char *alarm_enable,
unsigned char *alarm_flag)
{
int flags;
if (alarm_enable) {
dev_dbg(&client->dev, "%s:NCT3018Y_REG_CTRL\n", __func__);
flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
if (flags < 0)
return flags;
*alarm_enable = flags & NCT3018Y_BIT_AIE;
dev_dbg(&client->dev, "%s:alarm_enable:%x\n", __func__, *alarm_enable);
}
if (alarm_flag) {
dev_dbg(&client->dev, "%s:NCT3018Y_REG_ST\n", __func__);
flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_ST);
if (flags < 0)
return flags;
*alarm_flag = flags & NCT3018Y_BIT_AF;
dev_dbg(&client->dev, "%s:alarm_flag:%x\n", __func__, *alarm_flag);
}
return 0;
}
static irqreturn_t nct3018y_irq(int irq, void *dev_id)
{
struct nct3018y *nct3018y = i2c_get_clientdata(dev_id);
struct i2c_client *client = nct3018y->client;
int err;
unsigned char alarm_flag;
unsigned char alarm_enable;
dev_dbg(&client->dev, "%s:irq:%d\n", __func__, irq);
err = nct3018y_get_alarm_mode(nct3018y->client, &alarm_enable, &alarm_flag);
if (err)
return IRQ_NONE;
if (alarm_flag) {
dev_dbg(&client->dev, "%s:alarm flag:%x\n",
__func__, alarm_flag);
rtc_update_irq(nct3018y->rtc, 1, RTC_IRQF | RTC_AF);
nct3018y_set_alarm_mode(nct3018y->client, 0);
dev_dbg(&client->dev, "%s:IRQ_HANDLED\n", __func__);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
/*
* In the routines that deal directly with the nct3018y hardware, we use
* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
*/
static int nct3018y_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct i2c_client *client = to_i2c_client(dev);
unsigned char buf[10];
int err;
err = i2c_smbus_read_i2c_block_data(client, NCT3018Y_REG_ST, 1, buf);
if (err < 0)
return err;
if (!buf[0]) {
dev_dbg(&client->dev, " voltage <=1.7, date/time is not reliable.\n");
return -EINVAL;
}
err = i2c_smbus_read_i2c_block_data(client, NCT3018Y_REG_SC, sizeof(buf), buf);
if (err < 0)
return err;
tm->tm_sec = bcd2bin(buf[0] & 0x7F);
tm->tm_min = bcd2bin(buf[2] & 0x7F);
tm->tm_hour = bcd2bin(buf[4] & 0x3F);
tm->tm_wday = buf[6] & 0x07;
tm->tm_mday = bcd2bin(buf[7] & 0x3F);
tm->tm_mon = bcd2bin(buf[8] & 0x1F) - 1;
tm->tm_year = bcd2bin(buf[9]) + 100;
return 0;
}
static int nct3018y_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct i2c_client *client = to_i2c_client(dev);
struct nct3018y *nct3018y = dev_get_drvdata(dev);
unsigned char buf[4] = {0};
int err, flags;
int restore_flags = 0;
flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
if (flags < 0) {
dev_dbg(&client->dev, "Failed to read NCT3018Y_REG_CTRL.\n");
return flags;
}
/* Check and set TWO bit */
if (nct3018y->part_num == NCT3018Y_REG_PART_NCT3018Y && !(flags & NCT3018Y_BIT_TWO)) {
restore_flags = 1;
flags |= NCT3018Y_BIT_TWO;
err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags);
if (err < 0) {
dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL.\n");
return err;
}
}
buf[0] = bin2bcd(tm->tm_sec);
err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_SC, buf[0]);
if (err < 0) {
dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_SC\n");
return err;
}
buf[0] = bin2bcd(tm->tm_min);
err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_MN, buf[0]);
if (err < 0) {
dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_MN\n");
return err;
}
buf[0] = bin2bcd(tm->tm_hour);
err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_HR, buf[0]);
if (err < 0) {
dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_HR\n");
return err;
}
buf[0] = tm->tm_wday & 0x07;
buf[1] = bin2bcd(tm->tm_mday);
buf[2] = bin2bcd(tm->tm_mon + 1);
buf[3] = bin2bcd(tm->tm_year - 100);
err = i2c_smbus_write_i2c_block_data(client, NCT3018Y_REG_DW,
sizeof(buf), buf);
if (err < 0) {
dev_dbg(&client->dev, "Unable to write for day and mon and year\n");
return -EIO;
}
/* Restore TWO bit */
if (restore_flags) {
if (nct3018y->part_num == NCT3018Y_REG_PART_NCT3018Y)
flags &= ~NCT3018Y_BIT_TWO;
err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags);
if (err < 0) {
dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL.\n");
return err;
}
}
return err;
}
static int nct3018y_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
{
struct i2c_client *client = to_i2c_client(dev);
unsigned char buf[5];
int err;
err = i2c_smbus_read_i2c_block_data(client, NCT3018Y_REG_SCA,
sizeof(buf), buf);
if (err < 0) {
dev_dbg(&client->dev, "Unable to read date\n");
return -EIO;
}
dev_dbg(&client->dev, "%s: raw data is sec=%02x, min=%02x hr=%02x\n",
__func__, buf[0], buf[2], buf[4]);
tm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
tm->time.tm_min = bcd2bin(buf[2] & 0x7F);
tm->time.tm_hour = bcd2bin(buf[4] & 0x3F);
err = nct3018y_get_alarm_mode(client, &tm->enabled, &tm->pending);
if (err < 0)
return err;
dev_dbg(&client->dev, "%s:s=%d m=%d, hr=%d, enabled=%d, pending=%d\n",
__func__, tm->time.tm_sec, tm->time.tm_min,
tm->time.tm_hour, tm->enabled, tm->pending);
return 0;
}
static int nct3018y_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
{
struct i2c_client *client = to_i2c_client(dev);
int err;
dev_dbg(dev, "%s, sec=%d, min=%d hour=%d tm->enabled:%d\n",
__func__, tm->time.tm_sec, tm->time.tm_min, tm->time.tm_hour,
tm->enabled);
err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_SCA, bin2bcd(tm->time.tm_sec));
if (err < 0) {
dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_SCA\n");
return err;
}
err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_MNA, bin2bcd(tm->time.tm_min));
if (err < 0) {
dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_MNA\n");
return err;
}
err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_HRA, bin2bcd(tm->time.tm_hour));
if (err < 0) {
dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_HRA\n");
return err;
}
return nct3018y_set_alarm_mode(client, tm->enabled);
}
static int nct3018y_irq_enable(struct device *dev, unsigned int enabled)
{
dev_dbg(dev, "%s: alarm enable=%d\n", __func__, enabled);
return nct3018y_set_alarm_mode(to_i2c_client(dev), enabled);
}
static int nct3018y_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
struct i2c_client *client = to_i2c_client(dev);
int status, flags = 0;
switch (cmd) {
case RTC_VL_READ:
status = i2c_smbus_read_byte_data(client, NCT3018Y_REG_ST);
if (status < 0)
return status;
if (!(status & NCT3018Y_REG_BAT_MASK))
flags |= RTC_VL_DATA_INVALID;
return put_user(flags, (unsigned int __user *)arg);
default:
return -ENOIOCTLCMD;
}
}
#ifdef CONFIG_COMMON_CLK
/*
* Handling of the clkout
*/
#define clkout_hw_to_nct3018y(_hw) container_of(_hw, struct nct3018y, clkout_hw)
static const int clkout_rates[] = {
32768,
1024,
32,
1,
};
static unsigned long nct3018y_clkout_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct nct3018y *nct3018y = clkout_hw_to_nct3018y(hw);
struct i2c_client *client = nct3018y->client;
int flags;
flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CLKO);
if (flags < 0)
return 0;
flags &= NCT3018Y_REG_CLKO_F_MASK;
return clkout_rates[flags];
}
static long nct3018y_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
int i;
for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
if (clkout_rates[i] <= rate)
return clkout_rates[i];
return 0;
}
static int nct3018y_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct nct3018y *nct3018y = clkout_hw_to_nct3018y(hw);
struct i2c_client *client = nct3018y->client;
int i, flags;
flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CLKO);
if (flags < 0)
return flags;
for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
if (clkout_rates[i] == rate) {
flags &= ~NCT3018Y_REG_CLKO_F_MASK;
flags |= i;
return i2c_smbus_write_byte_data(client, NCT3018Y_REG_CLKO, flags);
}
return -EINVAL;
}
static int nct3018y_clkout_control(struct clk_hw *hw, bool enable)
{
struct nct3018y *nct3018y = clkout_hw_to_nct3018y(hw);
struct i2c_client *client = nct3018y->client;
int flags;
flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CLKO);
if (flags < 0)
return flags;
if (enable)
flags |= NCT3018Y_REG_CLKO_CKE;
else
flags &= ~NCT3018Y_REG_CLKO_CKE;
return i2c_smbus_write_byte_data(client, NCT3018Y_REG_CLKO, flags);
}
static int nct3018y_clkout_prepare(struct clk_hw *hw)
{
return nct3018y_clkout_control(hw, 1);
}
static void nct3018y_clkout_unprepare(struct clk_hw *hw)
{
nct3018y_clkout_control(hw, 0);
}
static int nct3018y_clkout_is_prepared(struct clk_hw *hw)
{
struct nct3018y *nct3018y = clkout_hw_to_nct3018y(hw);
struct i2c_client *client = nct3018y->client;
int flags;
flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CLKO);
if (flags < 0)
return flags;
return flags & NCT3018Y_REG_CLKO_CKE;
}
static const struct clk_ops nct3018y_clkout_ops = {
.prepare = nct3018y_clkout_prepare,
.unprepare = nct3018y_clkout_unprepare,
.is_prepared = nct3018y_clkout_is_prepared,
.recalc_rate = nct3018y_clkout_recalc_rate,
.round_rate = nct3018y_clkout_round_rate,
.set_rate = nct3018y_clkout_set_rate,
};
static struct clk *nct3018y_clkout_register_clk(struct nct3018y *nct3018y)
{
struct i2c_client *client = nct3018y->client;
struct device_node *node = client->dev.of_node;
struct clk *clk;
struct clk_init_data init;
init.name = "nct3018y-clkout";
init.ops = &nct3018y_clkout_ops;
init.flags = 0;
init.parent_names = NULL;
init.num_parents = 0;
nct3018y->clkout_hw.init = &init;
/* optional override of the clockname */
of_property_read_string(node, "clock-output-names", &init.name);
/* register the clock */
clk = devm_clk_register(&client->dev, &nct3018y->clkout_hw);
if (!IS_ERR(clk))
of_clk_add_provider(node, of_clk_src_simple_get, clk);
return clk;
}
#endif
static const struct rtc_class_ops nct3018y_rtc_ops = {
.read_time = nct3018y_rtc_read_time,
.set_time = nct3018y_rtc_set_time,
.read_alarm = nct3018y_rtc_read_alarm,
.set_alarm = nct3018y_rtc_set_alarm,
.alarm_irq_enable = nct3018y_irq_enable,
.ioctl = nct3018y_ioctl,
};
static int nct3018y_probe(struct i2c_client *client)
{
struct nct3018y *nct3018y;
int err, flags;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BLOCK_DATA))
return -ENODEV;
nct3018y = devm_kzalloc(&client->dev, sizeof(struct nct3018y),
GFP_KERNEL);
if (!nct3018y)
return -ENOMEM;
i2c_set_clientdata(client, nct3018y);
nct3018y->client = client;
device_set_wakeup_capable(&client->dev, 1);
flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
if (flags < 0) {
dev_dbg(&client->dev, "%s: read error\n", __func__);
return flags;
} else if (flags & NCT3018Y_BIT_TWO) {
dev_dbg(&client->dev, "%s: NCT3018Y_BIT_TWO is set\n", __func__);
}
nct3018y->part_num = i2c_smbus_read_byte_data(client, NCT3018Y_REG_PART);
if (nct3018y->part_num < 0) {
dev_dbg(&client->dev, "Failed to read NCT3018Y_REG_PART.\n");
return nct3018y->part_num;
} else {
nct3018y->part_num &= 0x03; /* Part number is corresponding to bit 0 and 1 */
if (nct3018y->part_num == NCT3018Y_REG_PART_NCT3018Y) {
flags = NCT3018Y_BIT_HF;
err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags);
if (err < 0) {
dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL.\n");
return err;
}
}
}
flags = 0;
err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_ST, flags);
if (err < 0) {
dev_dbg(&client->dev, "%s: write error\n", __func__);
return err;
}
nct3018y->rtc = devm_rtc_allocate_device(&client->dev);
if (IS_ERR(nct3018y->rtc))
return PTR_ERR(nct3018y->rtc);
nct3018y->rtc->ops = &nct3018y_rtc_ops;
nct3018y->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
nct3018y->rtc->range_max = RTC_TIMESTAMP_END_2099;
if (client->irq > 0) {
err = devm_request_threaded_irq(&client->dev, client->irq,
NULL, nct3018y_irq,
IRQF_ONESHOT | IRQF_TRIGGER_FALLING,
"nct3018y", client);
if (err) {
dev_dbg(&client->dev, "unable to request IRQ %d\n", client->irq);
return err;
}
} else {
clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, nct3018y->rtc->features);
clear_bit(RTC_FEATURE_ALARM, nct3018y->rtc->features);
}
#ifdef CONFIG_COMMON_CLK
/* register clk in common clk framework */
nct3018y_clkout_register_clk(nct3018y);
#endif
return devm_rtc_register_device(nct3018y->rtc);
}
static const struct i2c_device_id nct3018y_id[] = {
{ "nct3018y" },
{ }
};
MODULE_DEVICE_TABLE(i2c, nct3018y_id);
static const struct of_device_id nct3018y_of_match[] = {
{ .compatible = "nuvoton,nct3018y" },
{}
};
MODULE_DEVICE_TABLE(of, nct3018y_of_match);
static struct i2c_driver nct3018y_driver = {
.driver = {
.name = "rtc-nct3018y",
.of_match_table = nct3018y_of_match,
},
.probe = nct3018y_probe,
.id_table = nct3018y_id,
};
module_i2c_driver(nct3018y_driver);
MODULE_AUTHOR("Medad CChien <[email protected]>");
MODULE_AUTHOR("Mia Lin <[email protected]>");
MODULE_DESCRIPTION("Nuvoton NCT3018Y RTC driver");
MODULE_LICENSE("GPL");
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