Add driver support for I2C based Maxim max31329 real time clock. Signed-off-by: Jagath Jog J <jagathjog1996@xxxxxxxxx> --- 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 diff --git a/MAINTAINERS b/MAINTAINERS index 7032fcb0fd0f..d92ddab0958d 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -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@xxxxxxxxx> +L: linux-rtc@xxxxxxxxxxxxxxx +S: Maintained +F: Documentation/devicetree/bindings/rtc/maxim,max31329.yaml +F: drivers/rtc/max31329.c + MAXIRADIO FM RADIO RECEIVER DRIVER M: Hans Verkuil <hverkuil@xxxxxxxxx> L: linux-media@xxxxxxxxxxxxxxx diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index b8de25118ad0..d02cba94e121 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -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 diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index aab22bc63432..741216d2f9ca 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -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 diff --git a/drivers/rtc/rtc-max31329.c b/drivers/rtc/rtc-max31329.c new file mode 100644 index 000000000000..fbbe439a9a3b --- /dev/null +++ b/drivers/rtc/rtc-max31329.c @@ -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@xxxxxxxxx>"); +MODULE_DESCRIPTION("Maxim MAX31329 RTC driver"); +MODULE_LICENSE("GPL"); -- 2.17.1
