@@ -12478,6 +12478,13 @@ F: include/linux/mfd/max14577*.h
F: include/linux/mfd/max77686*.h
F: include/linux/mfd/max77693*.h
+MAXIM MAX31329 RTC DRIVER
+M: Jagath Jog J <jagathjog1996@gmail.com>
+L: linux-rtc@vger.kernel.org
+S: Maintained
+F: Documentation/devicetree/bindings/rtc/maxim,max31329.yaml
+F: drivers/rtc/max31329.c
+
MAXIRADIO FM RADIO RECEIVER DRIVER
M: Hans Verkuil <hverkuil@xs4all.nl>
L: linux-media@vger.kernel.org
@@ -393,6 +393,16 @@ config RTC_DRV_NCT3018Y
This driver can also be built as a module, if so, the module will be
called "rtc-nct3018y".
+config RTC_DRV_MAX31329
+ tristate "Maxim MAX31329"
+ select REGMAP_I2C
+ help
+ If you say yes here you will get support for the
+ RTC of Maxim MAX31329.
+
+ This driver can also be build as a module. If so, the module
+ will be called rtc-max31329.
+
config RTC_DRV_RK808
tristate "Rockchip RK805/RK808/RK809/RK817/RK818 RTC"
depends on MFD_RK808
@@ -97,6 +97,7 @@ obj-$(CONFIG_RTC_DRV_MAX8907) += rtc-max8907.o
obj-$(CONFIG_RTC_DRV_MAX8925) += rtc-max8925.o
obj-$(CONFIG_RTC_DRV_MAX8997) += rtc-max8997.o
obj-$(CONFIG_RTC_DRV_MAX8998) += rtc-max8998.o
+obj-$(CONFIG_RTC_DRV_MAX31329) += rtc-max31329.o
obj-$(CONFIG_RTC_DRV_MESON_VRTC)+= rtc-meson-vrtc.o
obj-$(CONFIG_RTC_DRV_MC13XXX) += rtc-mc13xxx.o
obj-$(CONFIG_RTC_DRV_MCP795) += rtc-mcp795.o
new file mode 100644
@@ -0,0 +1,507 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RTC driver for the Maxim MAX31329 Real-Time Clock
+ * Copyright (c) 2022 Jagath Jog J
+ *
+ * Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX31329.pdf
+ *
+ */
+
+#include <linux/bcd.h>
+#include <linux/bitfield.h>
+#include <linux/clk-provider.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+
+/* Register map */
+/* Config registers */
+#define MAX31329_STATUS_REG 0x00
+#define MAX31329_STATUS_A1F BIT(0)
+#define MAX31329_STATUS_OSF BIT(6)
+#define MAX31329_INT_EN_REG 0x01
+#define MAX31329_INT_EN_A1IE BIT(0)
+#define MAX31329_RTC_RESET_REG 0x02
+#define MAX31329_RTC_CONFIG1_REG 0x03
+#define MAX31329_RTC_CONFIG2_REG 0x04
+#define MAX31329_RTC_CONFIG2_ENCLKIN BIT(2)
+#define MAX31329_RTC_CONFIG2_ENCLKO BIT(7)
+#define MAX31329_RTC_CFG2_CLKOHZ_MSK GENMASK(6, 5)
+#define MAX31329_TIMER_CONFIG_REG 0x05
+
+/* Watch registers */
+#define MAX31329_SECONDS_REG 0x06
+#define MAX31329_MINUTES_REG 0x07
+#define MAX31329_HOURS_REG 0x08
+#define MAX31329_HOURS_F24_12 BIT(6)
+#define MAX31329_HOURS_AM_PM BIT(5)
+#define MAX31329_DAY_REG 0x09
+#define MAX31329_DATE_REG 0x0A
+#define MAX31329_MONTH_REG 0x0B
+#define MAX31329_MONTH_CENTURY BIT(7)
+#define MAX31329_YEAR_REG 0x0C
+#define MAX31329_WATCH_SEC_LEN 0x07
+#define REG_TO_OFFSET(_REG) ((_REG) - MAX31329_SECONDS_REG)
+
+/* Alarm registers */
+#define MAX31329_ALM1_SEC_REG 0x0D
+#define MAX31329_ALM1_MIN_REG 0x0E
+#define MAX31329_ALM1_HRS_REG 0x0F
+#define MAX31329_ALM1_DAY_DATE_REG 0x10
+#define MAX31329_ALM1_MON_REG 0x11
+#define MAX31329_ALM1_YEAR_REG 0x12
+#define MAX31329_ALM1_SEC_LEN 0x06
+
+#define MAX31329_PWR_MGMT_REG 0x18
+#define MAX31329_TRICKLE_REG 0x19
+#define MAX31329_TRICKLE_EN BIT(7)
+#define MAX31329_TRICKLE_DIODE_EN BIT(2)
+#define MAX31329_D_TRICKLE_OHMS GENMASK(3, 0)
+
+/* Ram registers */
+#define MAX31329_RAM0_START_REG 0x22
+#define MAX31329_RAM0_END_REG 0x61
+
+struct max31329_data {
+ struct regmap *regmap;
+ struct rtc_device *rtc;
+ int irq;
+#ifdef CONFIG_COMMON_CLK
+ struct clk_hw clkout_hw;
+#endif
+};
+
+/* resistance in kohms */
+static u32 max31329_trickle_ohms[] = {
+ 3000,
+ 6000,
+ 11000
+};
+
+static const struct regmap_config config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = MAX31329_RAM0_END_REG,
+};
+
+static int max31329_get_osc_status(struct device *dev)
+{
+ struct max31329_data *max31329 = dev_get_drvdata(dev);
+ unsigned int status;
+ int ret;
+
+ ret = regmap_read(max31329->regmap, MAX31329_STATUS_REG, &status);
+ if (ret)
+ return ret;
+
+ if (status & MAX31329_STATUS_OSF)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int max31329_alarm_irq_enable(struct device *dev, unsigned int enable)
+{
+ struct max31329_data *max31329 = dev_get_drvdata(dev);
+
+ return regmap_update_bits(max31329->regmap, MAX31329_INT_EN_REG,
+ MAX31329_INT_EN_A1IE,
+ enable ? MAX31329_INT_EN_A1IE : 0);
+}
+
+static int max31329_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ struct max31329_data *max31329 = dev_get_drvdata(dev);
+ struct rtc_time *const tm = &alarm->time;
+ unsigned int aie_en, aie_flag;
+ int ret;
+ u8 regs[6];
+
+ ret = regmap_bulk_read(max31329->regmap, MAX31329_ALM1_SEC_REG, regs,
+ MAX31329_ALM1_SEC_LEN);
+ if (ret)
+ return ret;
+
+ ret = regmap_read(max31329->regmap, MAX31329_INT_EN_REG, &aie_en);
+ if (ret)
+ return ret;
+
+ ret = regmap_read(max31329->regmap, MAX31329_STATUS_REG, &aie_flag);
+ if (ret)
+ return ret;
+
+ tm->tm_sec = bcd2bin(regs[REG_TO_OFFSET(MAX31329_SECONDS_REG)] & 0x7f);
+ tm->tm_min = bcd2bin(regs[REG_TO_OFFSET(MAX31329_MINUTES_REG)] & 0x7f);
+ tm->tm_hour = bcd2bin(regs[REG_TO_OFFSET(MAX31329_HOURS_REG)] & 0x3f);
+ tm->tm_mday = bcd2bin(regs[REG_TO_OFFSET(MAX31329_DATE_REG) - 1] & 0x3f);
+ tm->tm_mon = bcd2bin(regs[REG_TO_OFFSET(MAX31329_MONTH_REG) - 1] &
+ 0x1f) - 1;
+ tm->tm_year = bcd2bin(regs[REG_TO_OFFSET(MAX31329_YEAR_REG) - 1]) + 200;
+
+ alarm->enabled = FIELD_GET(MAX31329_INT_EN_A1IE, aie_en);
+ alarm->pending = FIELD_GET(MAX31329_STATUS_A1F, aie_flag) &&
+ alarm->enabled;
+
+ return 0;
+}
+
+static int max31329_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct max31329_data *max31329 = dev_get_drvdata(dev);
+ const struct rtc_time *tm = &alrm->time;
+ u8 regs[6], year;
+ int ret;
+
+ regs[REG_TO_OFFSET(MAX31329_SECONDS_REG)] = bin2bcd(tm->tm_sec) & 0x7F;
+ regs[REG_TO_OFFSET(MAX31329_MINUTES_REG)] = bin2bcd(tm->tm_min) & 0x7f;
+ regs[REG_TO_OFFSET(MAX31329_HOURS_REG)] = bin2bcd(tm->tm_hour) & 0x3f;
+ regs[REG_TO_OFFSET(MAX31329_DATE_REG) - 1] = bin2bcd(tm->tm_mday) & 0x3f;
+ regs[REG_TO_OFFSET(MAX31329_MONTH_REG) - 1] = bin2bcd(tm->tm_mon + 1) & 0x1f;
+
+ if (tm->tm_year >= 200)
+ return -EINVAL;
+
+ year = bin2bcd(tm->tm_year - 100);
+ regs[REG_TO_OFFSET(MAX31329_YEAR_REG) - 1] = year;
+
+ ret = regmap_bulk_write(max31329->regmap, MAX31329_ALM1_SEC_REG, regs,
+ MAX31329_ALM1_SEC_LEN);
+ if (ret)
+ return ret;
+
+ return max31329_alarm_irq_enable(dev, alrm->enabled);
+}
+
+static int max31329_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct max31329_data *max31329 = dev_get_drvdata(dev);
+ u8 data[7], century = 0;
+ int ret;
+
+ ret = max31329_get_osc_status(dev);
+ if (ret)
+ return ret;
+
+ ret = regmap_bulk_read(max31329->regmap, MAX31329_SECONDS_REG, data,
+ sizeof(data));
+ if (ret)
+ return ret;
+
+ tm->tm_sec = bcd2bin(data[REG_TO_OFFSET(MAX31329_SECONDS_REG)] & 0x7f);
+ tm->tm_min = bcd2bin(data[REG_TO_OFFSET(MAX31329_MINUTES_REG)] & 0x7f);
+ tm->tm_hour = bcd2bin(data[REG_TO_OFFSET(MAX31329_HOURS_REG)] & 0x3f);
+ /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
+ tm->tm_wday = bcd2bin(data[REG_TO_OFFSET(MAX31329_DAY_REG)] & 0x07) - 1;
+ tm->tm_mday = bcd2bin(data[REG_TO_OFFSET(MAX31329_DATE_REG)] & 0x3f);
+ /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
+ tm->tm_mon = bcd2bin(data[REG_TO_OFFSET(MAX31329_MONTH_REG)] & 0x1f) - 1;
+
+ century = data[REG_TO_OFFSET(MAX31329_MONTH_REG)] & MAX31329_MONTH_CENTURY;
+ tm->tm_year = bcd2bin(data[REG_TO_OFFSET(MAX31329_YEAR_REG)]) +
+ (century ? 200 : 100);
+
+ return 0;
+}
+
+static int max31329_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct max31329_data *max31329 = dev_get_drvdata(dev);
+ u8 regs[7];
+
+ regs[REG_TO_OFFSET(MAX31329_SECONDS_REG)] = bin2bcd(tm->tm_sec);
+ regs[REG_TO_OFFSET(MAX31329_MINUTES_REG)] = bin2bcd(tm->tm_min);
+ regs[REG_TO_OFFSET(MAX31329_HOURS_REG)] = bin2bcd(tm->tm_hour);
+ regs[REG_TO_OFFSET(MAX31329_DAY_REG)] = bin2bcd(tm->tm_wday + 1);
+ regs[REG_TO_OFFSET(MAX31329_DATE_REG)] = bin2bcd(tm->tm_mday);
+ regs[REG_TO_OFFSET(MAX31329_MONTH_REG)] = bin2bcd(tm->tm_mon + 1);
+
+ if (tm->tm_year >= 200)
+ regs[REG_TO_OFFSET(MAX31329_MONTH_REG)] |= MAX31329_MONTH_CENTURY;
+ regs[REG_TO_OFFSET(MAX31329_YEAR_REG)] = bin2bcd(tm->tm_year % 100);
+
+ return regmap_bulk_write(max31329->regmap, MAX31329_SECONDS_REG, regs,
+ MAX31329_WATCH_SEC_LEN);
+}
+
+static const struct rtc_class_ops max31329_rtc_ops = {
+ .read_time = max31329_read_time,
+ .set_time = max31329_set_time,
+ .read_alarm = max31329_read_alarm,
+ .set_alarm = max31329_set_alarm,
+ .alarm_irq_enable = max31329_alarm_irq_enable,
+};
+
+static irqreturn_t max31329_irq_handler(int irq, void *dev_id)
+{
+ struct device *dev = dev_id;
+ struct max31329_data *max31329 = dev_get_drvdata(dev);
+ unsigned int flags, controls;
+ unsigned long events = 0;
+ int ret;
+
+ ret = regmap_read(max31329->regmap, MAX31329_INT_EN_REG, &controls);
+ if (ret)
+ return IRQ_NONE;
+
+ ret = regmap_read(max31329->regmap, MAX31329_STATUS_REG, &flags);
+ if (ret)
+ return IRQ_NONE;
+
+ if (flags & MAX31329_STATUS_A1F) {
+ flags &= ~MAX31329_STATUS_A1F;
+ controls &= ~MAX31329_INT_EN_A1IE;
+ events = RTC_AF | RTC_IRQF;
+ }
+
+ if (events) {
+ rtc_update_irq(max31329->rtc, 1, events);
+ regmap_write(max31329->regmap, MAX31329_STATUS_REG, flags);
+ regmap_write(max31329->regmap, MAX31329_INT_EN_REG, controls);
+ return IRQ_HANDLED;
+ }
+
+ return IRQ_NONE;
+}
+
+static void max31329_trickle_config(struct device *dev)
+{
+ struct max31329_data *max31329 = dev_get_drvdata(dev);
+ u8 trickle_reg;
+ int ret, i;
+ u32 ohms;
+
+ /* Configure the trickle charger. */
+ ret = device_property_read_u32(dev, "trickle-resistor-ohms", &ohms);
+ if (ret)
+ return;
+
+ trickle_reg = MAX31329_TRICKLE_EN;
+ for (i = 1; i <= ARRAY_SIZE(max31329_trickle_ohms); i++) {
+ if (max31329_trickle_ohms[i - 1] == ohms) {
+ trickle_reg |= i;
+ regmap_write(max31329->regmap, MAX31329_TRICKLE_REG,
+ trickle_reg);
+ }
+ }
+}
+
+static int max31329_nvram_write(void *priv, unsigned int offset, void *val,
+ size_t bytes)
+{
+ struct regmap *max31329_regmap = (struct regmap *)priv;
+
+ return regmap_bulk_write(max31329_regmap,
+ MAX31329_RAM0_START_REG + offset,
+ val, bytes);
+}
+
+static int max31329_nvram_read(void *priv, unsigned int offset, void *val,
+ size_t bytes)
+{
+ struct regmap *max31329_regmap = (struct regmap *)priv;
+
+ return regmap_bulk_read(max31329_regmap,
+ MAX31329_RAM0_START_REG + offset,
+ val, bytes);
+}
+
+#ifdef CONFIG_COMMON_CLK
+#define clkout_hw_to_max31329(hw) container_of(hw, struct max31329_data, clkout_hw)
+
+static int clkout_rates[] = {
+ 1,
+ 4096,
+ 8192,
+ 32768
+};
+
+static unsigned long max31329_clkout_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct max31329_data *max31329 = clkout_hw_to_max31329(hw);
+ int clkout, ret;
+
+ ret = regmap_read(max31329->regmap, MAX31329_RTC_CONFIG2_REG, &clkout);
+ if (ret)
+ return 0;
+
+ return clkout_rates[FIELD_GET(MAX31329_RTC_CFG2_CLKOHZ_MSK, clkout)];
+}
+
+static long max31329_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 max31329_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct max31329_data *max31329 = clkout_hw_to_max31329(hw);
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
+ if (rate == clkout_rates[i])
+ return regmap_update_bits(max31329->regmap,
+ MAX31329_RTC_CONFIG2_REG,
+ MAX31329_RTC_CFG2_CLKOHZ_MSK,
+ FIELD_PREP(MAX31329_RTC_CFG2_CLKOHZ_MSK,
+ i));
+ return -EINVAL;
+}
+
+static int max31329_clkout_prepare(struct clk_hw *hw)
+{
+ struct max31329_data *max31329 = clkout_hw_to_max31329(hw);
+
+ return regmap_update_bits(max31329->regmap, MAX31329_RTC_CONFIG2_REG,
+ MAX31329_RTC_CONFIG2_ENCLKO,
+ MAX31329_RTC_CONFIG2_ENCLKO);
+}
+
+static void max31329_clkout_unprepare(struct clk_hw *hw)
+{
+ struct max31329_data *max31329 = clkout_hw_to_max31329(hw);
+
+ regmap_update_bits(max31329->regmap, MAX31329_RTC_CONFIG2_REG,
+ MAX31329_RTC_CONFIG2_ENCLKO,
+ FIELD_PREP(MAX31329_RTC_CONFIG2_ENCLKO, 0));
+}
+
+static int max31329_clkout_is_prepared(struct clk_hw *hw)
+{
+ struct max31329_data *max31329 = clkout_hw_to_max31329(hw);
+ int clkout, ret;
+
+ ret = regmap_read(max31329->regmap, MAX31329_RTC_CONFIG2_REG, &clkout);
+ if (ret)
+ return ret;
+
+ return !!(clkout & MAX31329_RTC_CONFIG2_ENCLKO);
+}
+
+static const struct clk_ops max31329_clkout_ops = {
+ .prepare = max31329_clkout_prepare,
+ .unprepare = max31329_clkout_unprepare,
+ .is_prepared = max31329_clkout_is_prepared,
+ .recalc_rate = max31329_clkout_recalc_rate,
+ .round_rate = max31329_clkout_round_rate,
+ .set_rate = max31329_clkout_set_rate,
+};
+
+static struct clk *max31329_clkout_register_clk(struct max31329_data *max31329,
+ struct i2c_client *client)
+{
+ struct device_node *node = client->dev.of_node;
+ struct clk_init_data init;
+ struct clk *clk;
+
+ init.name = "max31329-clkout";
+ init.ops = &max31329_clkout_ops;
+ init.flags = 0;
+ init.parent_names = NULL;
+ init.num_parents = 0;
+ max31329->clkout_hw.init = &init;
+
+ /* optional override of the clockname */
+ of_property_read_string(node, "clock-output-names", &init.name);
+
+ clk = devm_clk_register(&client->dev, &max31329->clkout_hw);
+ if (!IS_ERR(clk))
+ of_clk_add_provider(node, of_clk_src_simple_get, clk);
+
+ return clk;
+}
+#endif
+
+static int max31329_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct max31329_data *max31329;
+ int ret;
+ struct nvmem_config nvmem_cfg = {
+ .name = "max31329_nvram",
+ .word_size = 1,
+ .stride = 1,
+ .size = 64,
+ .type = NVMEM_TYPE_BATTERY_BACKED,
+ .reg_read = max31329_nvram_read,
+ .reg_write = max31329_nvram_write,
+ };
+
+ max31329 = devm_kzalloc(&client->dev, sizeof(*max31329), GFP_KERNEL);
+ if (!max31329)
+ return -ENOMEM;
+
+ max31329->regmap = devm_regmap_init_i2c(client, &config);
+ if (IS_ERR(max31329->regmap))
+ return PTR_ERR(max31329->regmap);
+
+ dev_set_drvdata(&client->dev, max31329);
+
+ max31329->rtc = devm_rtc_allocate_device(&client->dev);
+ if (IS_ERR(max31329->rtc))
+ return PTR_ERR(max31329->rtc);
+
+ max31329->rtc->ops = &max31329_rtc_ops;
+ max31329->irq = client->irq;
+ max31329->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+ max31329->rtc->range_max = RTC_TIMESTAMP_END_2199;
+
+ if (max31329->irq) {
+ ret = devm_request_threaded_irq(&client->dev, max31329->irq,
+ NULL, max31329_irq_handler,
+ IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+ "max31329", &client->dev);
+ if (ret)
+ return ret;
+ } else {
+ clear_bit(RTC_FEATURE_ALARM, max31329->rtc->features);
+ clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, max31329->rtc->features);
+ }
+
+ if (max31329->irq || device_property_read_bool(&client->dev,
+ "wakeup-source"))
+ device_init_wakeup(&client->dev, true);
+
+ ret = devm_rtc_register_device(max31329->rtc);
+ if (ret)
+ return ret;
+
+ max31329_trickle_config(&client->dev);
+
+ nvmem_cfg.priv = max31329->regmap;
+ devm_rtc_nvmem_register(max31329->rtc, &nvmem_cfg);
+
+#ifdef CONFIG_COMMON_CLK
+ max31329_clkout_register_clk(max31329, client);
+#endif
+
+ return 0;
+}
+
+static const __maybe_unused struct of_device_id max31329_of_match[] = {
+ { .compatible = "maxim,max31329", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, max31329_of_match);
+
+static struct i2c_driver max31329_driver = {
+ .driver = {
+ .name = "rtc-max31329",
+ .of_match_table = of_match_ptr(max31329_of_match),
+ },
+ .probe = max31329_probe,
+};
+module_i2c_driver(max31329_driver);
+
+MODULE_AUTHOR("Jagath Jog J <jagathjog1996@gmail.com>");
+MODULE_DESCRIPTION("Maxim MAX31329 RTC driver");
+MODULE_LICENSE("GPL");
Add driver support for I2C based Maxim max31329 real time clock. Signed-off-by: Jagath Jog J <jagathjog1996@gmail.com> --- MAINTAINERS | 7 + drivers/rtc/Kconfig | 10 + drivers/rtc/Makefile | 1 + drivers/rtc/rtc-max31329.c | 507 +++++++++++++++++++++++++++++++++++++ 4 files changed, 525 insertions(+) create mode 100644 drivers/rtc/rtc-max31329.c