diff options
Diffstat (limited to 'drivers/rtc/rtc-nct3018y.c')
| -rw-r--r-- | drivers/rtc/rtc-nct3018y.c | 553 |
1 files changed, 553 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-nct3018y.c b/drivers/rtc/rtc-nct3018y.c new file mode 100644 index 000000000000..d43acd3920ed --- /dev/null +++ b/drivers/rtc/rtc-nct3018y.c @@ -0,0 +1,553 @@ +// 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_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 */ + +struct nct3018y { + struct rtc_device *rtc; + struct i2c_client *client; +#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; + } + + 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_enable:%x alarm_flag:%x\n", + __func__, *alarm_enable, *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); + unsigned char buf[4] = {0}; + int 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; + } + + 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, + const struct i2c_device_id *id) +{ + 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__); + } + + 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; + } + + 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", 0 }, + { } +}; +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 = of_match_ptr(nct3018y_of_match), + }, + .probe = nct3018y_probe, + .id_table = nct3018y_id, +}; + +module_i2c_driver(nct3018y_driver); + +MODULE_AUTHOR("Medad CChien <ctcchien@nuvoton.com>"); +MODULE_AUTHOR("Mia Lin <mimi05633@gmail.com>"); +MODULE_DESCRIPTION("Nuvoton NCT3018Y RTC driver"); +MODULE_LICENSE("GPL"); |