Adding support for Analog Devices MAX313XX series RTCs. Signed-off-by: Ibrahim Tilki <Ibrahim.Tilki@xxxxxxxxxx> Signed-off-by: Zeynep Arslanbenzer <Zeynep.Arslanbenzer@xxxxxxxxxx> --- drivers/rtc/Kconfig | 11 + drivers/rtc/Makefile | 1 + drivers/rtc/rtc-max313xx.c | 1292 ++++++++++++++++++++++++++++++++++++ 3 files changed, 1304 insertions(+) create mode 100644 drivers/rtc/rtc-max313xx.c diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index b8de25118..71ea390dc 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -323,6 +323,17 @@ config RTC_DRV_LP8788 help Say Y to enable support for the LP8788 RTC/ALARM driver. +config RTC_DRV_MAX313XX + tristate "Analog Devices MAX313XX RTC driver" + depends on I2C + select REGMAP_I2C + help + If you say yes here you will get support for the + Analog Devices MAX313XX series RTC family. + + This driver can also be built as a module. If so, the module + will be called rtc-max313xx. + config RTC_DRV_MAX6900 tristate "Maxim MAX6900" help diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index aab22bc63..3d1aab897 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -89,6 +89,7 @@ obj-$(CONFIG_RTC_DRV_M41T94) += rtc-m41t94.o obj-$(CONFIG_RTC_DRV_M48T35) += rtc-m48t35.o obj-$(CONFIG_RTC_DRV_M48T59) += rtc-m48t59.o obj-$(CONFIG_RTC_DRV_M48T86) += rtc-m48t86.o +obj-$(CONFIG_RTC_DRV_MAX313XX) += rtc-max313xx.o obj-$(CONFIG_RTC_DRV_MAX6900) += rtc-max6900.o obj-$(CONFIG_RTC_DRV_MAX6902) += rtc-max6902.o obj-$(CONFIG_RTC_DRV_MAX6916) += rtc-max6916.o diff --git a/drivers/rtc/rtc-max313xx.c b/drivers/rtc/rtc-max313xx.c new file mode 100644 index 000000000..1c1ca323f --- /dev/null +++ b/drivers/rtc/rtc-max313xx.c @@ -0,0 +1,1292 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Analog Devices MAX313XX series I2C RTC driver + * + * Copyright 2022 Analog Devices Inc. + */ +#include <asm-generic/unaligned.h> +#include <linux/bcd.h> +#include <linux/bitfield.h> +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/hwmon.h> +#include <linux/i2c.h> +#include <linux/regmap.h> +#include <linux/rtc.h> +#include <linux/util_macros.h> +#include <linux/watchdog.h> + +/* common registers */ +#define MAX313XX_INT_ALARM1 BIT(0) +#define MAX313XX_INT_ALARM2 BIT(1) +#define MAX313XX_HRS_F_12_24 BIT(6) +#define MAX313XX_HRS_F_AM_PM BIT(5) +#define MAX313XX_MONTH_CENTURY BIT(7) + +#define MAX313XX_TMR_CFG_ENABLE BIT(4) +#define MAX313XX_TMR_CFG_FREQ_MASK GENMASK(1, 0) +#define MAX313XX_TMR_CFG_FREQ_16HZ 0x03 + +#define MAX313XX_REG_MINUTE 0x01 +#define MAX313XX_REG_HOUR 0x02 + +#define MAX313XX_TIME_SIZE 0x07 + +/* device specific registers */ +#define MAX3134X_CFG_REG 0x00 +#define MAX3134X_CFG_INIT_MASK (BIT(0) | BIT(3)) +#define MAX3134X_CFG_INIT_VALUE 0x01 + +#define MAX3134X_CFG2_REG 0x01 +#define MAX3134X_CFG2_SET_RTC BIT(1) + +#define MAX31341_TRICKLE_RES_MASK GENMASK(1, 0) +#define MAX31341_TRICKLE_DIODE_EN BIT(2) +#define MAX31341_TRICKLE_ENABLE_BIT BIT(3) +#define MAX31341_POWER_MGMT_REG 0x56 +#define MAX31341_POWER_MGMT_TRICKLE_BIT BIT(0) + +#define MAX3133X_TRICKLE_RES_MASK GENMASK(2, 1) +#define MAX3133X_TRICKLE_DIODE_EN BIT(3) +#define MAX3133X_TRICKLE_ENABLE_BIT BIT(0) + +#define MAX31329_TRICKLE_ENABLE_BIT BIT(7) +#define MAX31343_TRICKLE_ENABLE_MASK GENMASK(7, 4) +#define MAX31343_TRICKLE_ENABLE_CODE 5 +#define MAX31329_43_TRICKLE_RES_MASK GENMASK(1, 0) +#define MAX31329_43_TRICKLE_DIODE_EN BIT(2) + +#define MAX31329_CONFIG2_REG 0x04 +#define MAX31329_CONFIG2_CLKIN_EN BIT(2) +#define MAX31329_CONFIG2_CLKIN_FREQ GENMASK(1, 0) + +#define MAX31341_42_CONFIG1_REG 0x00 +#define MAX31341_42_CONFIG1_CLKIN_EN BIT(7) +#define MAX31341_42_CONFIG1_CLKIN_FREQ GENMASK(5, 4) + +enum max313xx_ids { + ID_MAX31328, + ID_MAX31329, + ID_MAX31331, + ID_MAX31334, + ID_MAX31341, + ID_MAX31342, + ID_MAX31343, + MAX313XX_ID_NR +}; + +struct clkout_cfg { + const int *freq_avail; + u8 freq_size; + u8 freq_pos; + u8 reg; + u8 en_bit; + bool en_invert; +}; + +struct chip_desc { + struct clkout_cfg *clkout; + const char *clkout_name; + u8 sec_reg; + u8 alarm1_sec_reg; + + u8 int_en_reg; + u8 int_status_reg; + + u8 timer_cfg_reg; + u8 timer_count_reg; + + u8 ram_reg; + u8 ram_size; + + u8 temp_reg; + + u8 trickle_reg; +}; + +#define clk_hw_to_max313xx(_hw) container_of(_hw, struct max313xx, clkout) + +struct max313xx { + enum max313xx_ids id; + struct regmap *regmap; + struct rtc_device *rtc; + struct watchdog_device wdd; + struct clk_hw clkout; + struct clk *clkin; + const struct chip_desc *chip; + int irqs[2]; + int irq; +}; + +static const int max313xx_clkin_freq[] = { 1, 50, 60, 32768 }; + +static const int max31328_clkout_freq[] = { 1, 1024, 4096, 8192 }; +static const int max31329_clkout_freq[] = { 1, 4096, 8192, 32768 }; +static const int max3133x_clkout_freq[] = { 1, 64, 1024, 32768 }; +static const int max31341_42_clkout_freq[] = { 1, 50, 60, 32768 }; +static const int max31343_clkout_freq[] = { 1, 2, 4, 8, 16, 32, 64, 128, 32875 }; + +static struct clkout_cfg max31328_clkout = { + .freq_avail = max31328_clkout_freq, + .freq_size = ARRAY_SIZE(max31328_clkout_freq), + .freq_pos = 3, + .reg = 0x0E, + .en_bit = BIT(3), + .en_invert = true, +}; + +static struct clkout_cfg max31329_clkout = { + .freq_avail = max31329_clkout_freq, + .freq_size = ARRAY_SIZE(max31329_clkout_freq), + .freq_pos = 5, + .reg = 0x04, + .en_bit = BIT(7), +}; + +static struct clkout_cfg max3133x_clkout = { + .freq_avail = max3133x_clkout_freq, + .freq_size = ARRAY_SIZE(max3133x_clkout_freq), + .freq_pos = 0, + .reg = 0x04, + .en_bit = BIT(2), +}; + +static struct clkout_cfg max31341_42_clkout = { + .freq_avail = max31341_42_clkout_freq, + .freq_size = ARRAY_SIZE(max31341_42_clkout_freq), + .freq_pos = 1, + .reg = 0x00, + .en_bit = BIT(6), + .en_invert = true, +}; + +static struct clkout_cfg max31343_clkout = { + .freq_avail = max31343_clkout_freq, + .freq_size = ARRAY_SIZE(max31343_clkout_freq), + .freq_pos = 3, + .reg = 0x04, + .en_bit = BIT(7), +}; + +static const struct chip_desc chip[MAX313XX_ID_NR] = { + [ID_MAX31328] = { + .int_en_reg = 0x0E, + .int_status_reg = 0x0F, + .sec_reg = 0x00, + .alarm1_sec_reg = 0x07, + .temp_reg = 0x11, + .clkout = &max31328_clkout, + .clkout_name = "max31328-sqw", + }, + [ID_MAX31329] = { + .int_en_reg = 0x01, + .int_status_reg = 0x00, + .sec_reg = 0x06, + .alarm1_sec_reg = 0x0D, + .timer_cfg_reg = 0x05, + .timer_count_reg = 0x16, + .ram_reg = 0x22, + .ram_size = 64, + .trickle_reg = 0x19, + .clkout = &max31329_clkout, + .clkout_name = "max31329-clkout", + }, + [ID_MAX31331] = { + .int_en_reg = 0x01, + .int_status_reg = 0x00, + .sec_reg = 0x08, + .alarm1_sec_reg = 0x0F, + .timer_cfg_reg = 0x06, + .timer_count_reg = 0x18, + .ram_reg = 0x20, + .ram_size = 32, + .trickle_reg = 0x1B, + .clkout = &max3133x_clkout, + .clkout_name = "max31331-clkout", + }, + [ID_MAX31334] = { + .int_en_reg = 0x01, + .int_status_reg = 0x00, + .sec_reg = 0x09, + .alarm1_sec_reg = 0x10, + .timer_cfg_reg = 0x06, + /* 16-bit timer */ + .timer_count_reg = 0x19, + .ram_reg = 0x30, + .ram_size = 32, + .trickle_reg = 0x1E, + .clkout = &max3133x_clkout, + .clkout_name = "max31334-clkout", + }, + [ID_MAX31341] = { + .int_en_reg = 0x04, + .int_status_reg = 0x05, + .sec_reg = 0x06, + .alarm1_sec_reg = 0x0D, + .timer_cfg_reg = 0x03, + .timer_count_reg = 0x14, + .ram_reg = 0x16, + .ram_size = 64, + .trickle_reg = 0x57, + .clkout = &max31341_42_clkout, + .clkout_name = "max31341-clkout", + }, + [ID_MAX31342] = { + .int_en_reg = 0x04, + .int_status_reg = 0x05, + .sec_reg = 0x06, + .alarm1_sec_reg = 0x0D, + .timer_cfg_reg = 0x03, + .timer_count_reg = 0x16, + .clkout = &max31341_42_clkout, + .clkout_name = "max31342-clkout", + }, + [ID_MAX31343] = { + .int_en_reg = 0x01, + .int_status_reg = 0x00, + .sec_reg = 0x06, + .alarm1_sec_reg = 0x0D, + .timer_cfg_reg = 0x05, + .timer_count_reg = 0x16, + .ram_reg = 0x22, + .ram_size = 64, + .temp_reg = 0x1A, + .trickle_reg = 0x19, + .clkout = &max31343_clkout, + .clkout_name = "max31343-sqw", + }, +}; + +static const u32 max313xx_trickle_ohms[] = { 3000, 6000, 11000 }; + +static bool max313xx_volatile_reg(struct device *dev, unsigned int reg) +{ + struct max313xx *rtc = dev_get_drvdata(dev); + const struct chip_desc *chip = rtc->chip; + + /* time keeping registers */ + if (reg >= chip->sec_reg && reg < chip->sec_reg + MAX313XX_TIME_SIZE) + return true; + + /* interrupt status register */ + if (reg == chip->int_status_reg) + return true; + + /* temperature registers */ + if (chip->temp_reg && + (reg == chip->temp_reg || reg == chip->temp_reg + 1)) + return true; + + /* timer count registers */ + return reg == chip->timer_count_reg || + (rtc->id == ID_MAX31334 && reg == chip->timer_count_reg + 1); +} + +static const struct regmap_config regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .cache_type = REGCACHE_RBTREE, + .volatile_reg = max313xx_volatile_reg, +}; + +static int max313xx_read_time(struct device *dev, struct rtc_time *t) +{ + struct max313xx *rtc = dev_get_drvdata(dev); + u8 regs[7]; + int ret; + + ret = regmap_bulk_read(rtc->regmap, rtc->chip->sec_reg, regs, 7); + if (ret) + return ret; + + t->tm_sec = bcd2bin(regs[0] & 0x7f); + t->tm_min = bcd2bin(regs[1] & 0x7f); + t->tm_hour = bcd2bin(regs[2] & 0x3f); + t->tm_wday = bcd2bin(regs[3] & 0x07) - 1; + t->tm_mday = bcd2bin(regs[4] & 0x3f); + t->tm_mon = bcd2bin(regs[5] & 0x1f) - 1; + t->tm_year = bcd2bin(regs[6]) + 100; + + if (FIELD_GET(MAX313XX_MONTH_CENTURY, regs[5])) + t->tm_year += 100; + + return 0; +} + +static int max313xx_set_time(struct device *dev, struct rtc_time *t) +{ + struct max313xx *rtc = dev_get_drvdata(dev); + u8 regs[7]; + int ret; + + if (t->tm_year < 100 || t->tm_year >= 300) + return -EINVAL; + + regs[0] = bin2bcd(t->tm_sec); + regs[1] = bin2bcd(t->tm_min); + regs[2] = bin2bcd(t->tm_hour); + regs[3] = bin2bcd(t->tm_wday + 1); + regs[4] = bin2bcd(t->tm_mday); + regs[5] = bin2bcd(t->tm_mon + 1); + + if (t->tm_year >= 200) { + regs[5] |= FIELD_PREP(MAX313XX_MONTH_CENTURY, 1); + regs[6] = bin2bcd(t->tm_year - 200); + } else { + regs[6] = bin2bcd(t->tm_year - 100); + } + + /* Clkin needs to be disabled before setting time. */ + if (rtc->clkin) { + switch (rtc->id) { + case ID_MAX31341: + case ID_MAX31342: + ret = regmap_clear_bits(rtc->regmap, + MAX31341_42_CONFIG1_REG, + MAX31341_42_CONFIG1_CLKIN_EN); + break; + default: + ret = 0; + } + if (ret) + return ret; + } + + ret = regmap_bulk_write(rtc->regmap, rtc->chip->sec_reg, regs, 7); + if (ret) + return ret; + + switch (rtc->id) { + case ID_MAX31341: + case ID_MAX31342: + ret = regmap_set_bits(rtc->regmap, MAX3134X_CFG2_REG, + MAX3134X_CFG2_SET_RTC); + if (ret) + return ret; + + fsleep(10000); + + ret = regmap_clear_bits(rtc->regmap, MAX3134X_CFG2_REG, + MAX3134X_CFG2_SET_RTC); + if (ret) + return ret; + + if (rtc->clkin) + ret = regmap_set_bits(rtc->regmap, + MAX31341_42_CONFIG1_REG, + MAX31341_42_CONFIG1_CLKIN_EN); + + break; + default: + break; + } + + return ret; +} + +static int max313xx_read_alarm(struct device *dev, struct rtc_wkalrm *t) +{ + struct max313xx *rtc = dev_get_drvdata(dev); + unsigned int status, int_en; + struct rtc_time time; + u8 regs[6]; + int ret; + + ret = regmap_bulk_read(rtc->regmap, rtc->chip->alarm1_sec_reg, regs, + sizeof(regs)); + if (ret) + return ret; + + t->time.tm_sec = bcd2bin(regs[0] & 0x7f); + t->time.tm_min = bcd2bin(regs[1] & 0x7f); + t->time.tm_hour = bcd2bin(regs[2] & 0x3f); + t->time.tm_mday = bcd2bin(regs[3] & 0x3f); + t->time.tm_mon = bcd2bin(regs[4] & 0x1f) - 1; + t->time.tm_year = bcd2bin(regs[5]) + 100; + + ret = max313xx_read_time(dev, &time); + if (ret) + return ret; + + if (time.tm_year >= 200) + t->time.tm_year += 100; + + ret = regmap_read(rtc->regmap, rtc->chip->int_status_reg, &status); + if (ret) + return ret; + + ret = regmap_read(rtc->regmap, rtc->chip->int_en_reg, &int_en); + if (ret) + return ret; + + t->enabled = FIELD_GET(MAX313XX_INT_ALARM1, int_en); + t->pending = FIELD_GET(MAX313XX_INT_ALARM1, status); + + return 0; +} + +static int max313xx_set_alarm(struct device *dev, struct rtc_wkalrm *t) +{ + struct max313xx *rtc = dev_get_drvdata(dev); + struct rtc_time time; + unsigned int reg; + u8 regs[6]; + int ret; + + regs[0] = bin2bcd(t->time.tm_sec); + regs[1] = bin2bcd(t->time.tm_min); + regs[2] = bin2bcd(t->time.tm_hour); + regs[3] = bin2bcd(t->time.tm_mday); + regs[4] = bin2bcd(t->time.tm_mon + 1); + + if (t->time.tm_year >= 200) { + /* + * Century bit is shared between time and alarm registers so + * make sure that new alarm and RTC time is in the same century. + */ + ret = max313xx_read_time(dev, &time); + if (ret) + return ret; + + if (time.tm_year < 200) + return -EINVAL; + + regs[5] = bin2bcd(t->time.tm_year - 200); + } else if (t->time.tm_year >= 100) { + regs[5] = bin2bcd(t->time.tm_year - 100); + } else { + return -EINVAL; + } + + ret = regmap_bulk_write(rtc->regmap, rtc->chip->alarm1_sec_reg, regs, + sizeof(regs)); + if (ret) + return ret; + + reg = FIELD_PREP(MAX313XX_INT_ALARM1, t->enabled); + ret = regmap_update_bits(rtc->regmap, rtc->chip->int_en_reg, + MAX313XX_INT_ALARM1 | MAX313XX_INT_ALARM2, + reg); + if (ret) + return ret; + + /* Clear status register */ + return regmap_read(rtc->regmap, rtc->chip->int_status_reg, ®); +} + +static int max313xx_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct max313xx *rtc = dev_get_drvdata(dev); + + return regmap_update_bits(rtc->regmap, rtc->chip->int_en_reg, + MAX313XX_INT_ALARM1, + FIELD_PREP(MAX313XX_INT_ALARM1, enabled)); +} + +static const struct rtc_class_ops max3133x_rtc_ops = { + .read_time = max313xx_read_time, + .set_time = max313xx_set_time, + .read_alarm = max313xx_read_alarm, + .set_alarm = max313xx_set_alarm, + .alarm_irq_enable = max313xx_alarm_irq_enable, +}; + +static irqreturn_t max313xx_irq(int irq, void *dev_id) +{ + struct max313xx *rtc = dev_id; + struct mutex *lock = &rtc->rtc->ops_lock; + int stat, ret; + + mutex_lock(lock); + ret = regmap_read(rtc->regmap, rtc->chip->int_status_reg, &stat); + if (ret) + goto out; + + if (FIELD_GET(MAX313XX_INT_ALARM1, stat)) { + ret = regmap_update_bits(rtc->regmap, rtc->chip->int_en_reg, + MAX313XX_INT_ALARM1, 0); + if (ret) + goto out; + + rtc_update_irq(rtc->rtc, 1, RTC_AF | RTC_IRQF); + } + +out: + mutex_unlock(lock); + + return IRQ_HANDLED; +} + +static int max313xx_convert_24hr(struct max313xx *rtc) +{ + u8 reg[7], hour; + int ret; + + switch (rtc->id) { + case ID_MAX31341: + case ID_MAX31342: + case ID_MAX31343: + return 0; + default: + break; + } + + ret = regmap_bulk_read(rtc->regmap, rtc->chip->sec_reg, reg, 7); + if (ret) + return ret; + + /* Already in 24Hr mode */ + if (!FIELD_GET(MAX313XX_HRS_F_12_24, reg[MAX313XX_REG_HOUR])) + return 0; + + /* Convert to 24Hr */ + hour = bcd2bin(reg[MAX313XX_REG_HOUR] & 0x1f); + if (hour == 12) + hour = 0; + + if (FIELD_GET(MAX313XX_HRS_F_AM_PM, reg[MAX313XX_REG_HOUR])) + hour += 12; + + reg[MAX313XX_REG_HOUR] = bin2bcd(hour); + /* + * If minute is 59, write all registers in case hour register + * gets updated during read-write cycle + */ + if (reg[MAX313XX_REG_MINUTE] == 0x59) + return regmap_bulk_write(rtc->regmap, rtc->chip->sec_reg, reg, 7); + + return regmap_write(rtc->regmap, rtc->chip->sec_reg + MAX313XX_REG_HOUR, + reg[MAX313XX_REG_HOUR]); +} + +static int max313xx_nvmem_reg_read(void *priv, unsigned int offset, + void *val, size_t bytes) +{ + struct max313xx *rtc = priv; + unsigned int reg = rtc->chip->ram_reg + offset; + + return regmap_bulk_read(rtc->regmap, reg, val, bytes); +} + +static int max313xx_nvmem_reg_write(void *priv, unsigned int offset, + void *val, size_t bytes) +{ + struct max313xx *rtc = priv; + unsigned int reg = rtc->chip->ram_reg + offset; + + return regmap_bulk_write(rtc->regmap, reg, val, bytes); +} + +struct nvmem_config max313xx_nvmem_cfg = { + .reg_read = max313xx_nvmem_reg_read, + .reg_write = max313xx_nvmem_reg_write, + .word_size = 8, +}; + +static unsigned long max313xx_clkout_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct max313xx *rtc = clk_hw_to_max313xx(hw); + const struct clkout_cfg *clkout = rtc->chip->clkout; + unsigned int freq_mask; + unsigned int reg; + int ret; + + ret = regmap_read(rtc->regmap, clkout->reg, ®); + if (ret) + return 0; + + freq_mask = __roundup_pow_of_two(clkout->freq_size) - 1; + + return clkout->freq_avail[(reg >> clkout->freq_pos) & freq_mask]; +} + +static long max313xx_clkout_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + struct max313xx *rtc = clk_hw_to_max313xx(hw); + struct clkout_cfg *clkout = rtc->chip->clkout; + int index; + + index = find_closest(rate, clkout->freq_avail, clkout->freq_size); + return clkout->freq_avail[index]; +} + +static int max313xx_clkout_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct max313xx *rtc = clk_hw_to_max313xx(hw); + struct clkout_cfg *clkout = rtc->chip->clkout; + unsigned int freq_mask; + int index; + + index = find_closest(rate, clkout->freq_avail, clkout->freq_size); + freq_mask = __roundup_pow_of_two(clkout->freq_size) - 1; + + return regmap_update_bits(rtc->regmap, clkout->reg, + freq_mask << clkout->freq_pos, + index << clkout->freq_pos); +} + +static int max313xx_clkout_enable(struct clk_hw *hw) +{ + struct max313xx *rtc = clk_hw_to_max313xx(hw); + struct clkout_cfg *clkout = rtc->chip->clkout; + + if (clkout->en_invert) + return regmap_clear_bits(rtc->regmap, clkout->reg, + clkout->en_bit); + + return regmap_set_bits(rtc->regmap, clkout->reg, clkout->en_bit); +} + +static void max313xx_clkout_disable(struct clk_hw *hw) +{ + struct max313xx *rtc = clk_hw_to_max313xx(hw); + struct clkout_cfg *clkout = rtc->chip->clkout; + + switch (rtc->id) { + case ID_MAX31331: + case ID_MAX31334: + if (rtc->irq > 0) { + dev_err(rtc->rtc->dev.parent, + "clkout cannot be disabled when IRQ is requested"); + return; + } + default: + break; + } + + if (clkout->en_invert) + regmap_set_bits(rtc->regmap, clkout->reg, clkout->en_bit); + else + regmap_clear_bits(rtc->regmap, clkout->reg, clkout->en_bit); +} + +static int max313xx_clkout_is_enabled(struct clk_hw *hw) +{ + struct max313xx *rtc = clk_hw_to_max313xx(hw); + struct clkout_cfg *clkout = rtc->chip->clkout; + unsigned int reg; + int ret; + + ret = regmap_read(rtc->regmap, clkout->reg, ®); + if (ret) + return ret; + + return !!(reg & clkout->en_bit) ^ clkout->en_invert; +} + +static const struct clk_ops max313xx_clkout_ops = { + .recalc_rate = max313xx_clkout_recalc_rate, + .round_rate = max313xx_clkout_round_rate, + .set_rate = max313xx_clkout_set_rate, + .enable = max313xx_clkout_enable, + .disable = max313xx_clkout_disable, + .is_enabled = max313xx_clkout_is_enabled, +}; + +struct clk_init_data max313xx_clk_init = { + .name = "max313xx-clkout", + .ops = &max313xx_clkout_ops, +}; + +static int max313xx_read_temp(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + struct max313xx *rtc = dev_get_drvdata(dev); + struct chip_desc desc = chip[rtc->id]; + u8 reg[2]; + s16 temp; + int ret; + + if (type != hwmon_temp || attr != hwmon_temp_input) + return -EOPNOTSUPP; + + ret = regmap_bulk_read(rtc->regmap, desc.temp_reg, reg, 2); + if (ret) + return ret; + + temp = get_unaligned_be16(reg); + + *val = (temp / 64) * 250; + + return 0; +} + +static umode_t max313xx_is_visible(const void *data, + enum hwmon_sensor_types type, + u32 attr, int channel) +{ + if (type == hwmon_temp && attr == hwmon_temp_input) + return 0444; + + return 0; +} + +static const struct hwmon_channel_info *max313xx_info[] = { + HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT), + NULL +}; + +static const struct hwmon_ops max313xx_hwmon_ops = { + .is_visible = max313xx_is_visible, + .read = max313xx_read_temp, +}; + +static const struct hwmon_chip_info max313xx_chip_info = { + .ops = &max313xx_hwmon_ops, + .info = max313xx_info, +}; + +static int max313xx_wdt_start(struct watchdog_device *wdd) +{ + struct max313xx *rtc = watchdog_get_drvdata(wdd); + + return regmap_set_bits(rtc->regmap, rtc->chip->timer_cfg_reg, + MAX313XX_TMR_CFG_ENABLE); +} + +static int max313xx_wdt_stop(struct watchdog_device *wdd) +{ + struct max313xx *rtc = watchdog_get_drvdata(wdd); + + return regmap_clear_bits(rtc->regmap, rtc->chip->timer_cfg_reg, + MAX313XX_TMR_CFG_ENABLE); +} + +static int max313xx_wdt_ping(struct watchdog_device *wdd) +{ + int ret; + + ret = max313xx_wdt_stop(wdd); + if (ret) + return ret; + + return max313xx_wdt_start(wdd); +} + +static int max313xx_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int new_timeout) +{ + struct max313xx *rtc = watchdog_get_drvdata(wdd); + unsigned int reg = rtc->chip->timer_count_reg; + unsigned int regval = new_timeout * 16; + unsigned int tmr_cfg; + u8 tmr_16[2]; + int ret; + + switch (rtc->id) { + case ID_MAX31334: + if (regval > 0xFFFF) + return -EINVAL; + break; + default: + if (regval > 255) + return -EINVAL; + } + + /* timer has to be disabled before writing timer_init */ + ret = regmap_read(rtc->regmap, rtc->chip->timer_cfg_reg, &tmr_cfg); + if (ret) + return ret; + + ret = max313xx_wdt_stop(wdd); + if (ret) + return ret; + + switch (rtc->id) { + case ID_MAX31334: + tmr_16[0] = regval >> 8; + tmr_16[1] = regval & 0xFF; + + ret = regmap_bulk_write(rtc->regmap, reg + 2, tmr_16, 2); + break; + default: + ret = regmap_write(rtc->regmap, reg + 1, regval); + } + + if (ret) + return ret; + + wdd->timeout = new_timeout; + + /* restore timer cfg */ + return regmap_write(rtc->regmap, rtc->chip->timer_cfg_reg, tmr_cfg); +} + +static unsigned int max313xx_wdt_get_timeleft(struct watchdog_device *wdd) +{ + struct max313xx *rtc = watchdog_get_drvdata(wdd); + unsigned int reg; + u8 regs[2]; + int ret; + + switch (rtc->id) { + case ID_MAX31334: + ret = regmap_bulk_read(rtc->regmap, rtc->chip->timer_count_reg, + regs, 2); + reg = get_unaligned_be16(regs); + break; + default: + ret = regmap_read(rtc->regmap, rtc->chip->timer_count_reg, ®); + } + + if (ret) { + dev_err(rtc->rtc->dev.parent, "cannot read timer value"); + return 0; + } + + return reg / 16; +} + +static const struct watchdog_info max313xx_wdt_info = { + .identity = "MAX313XX Watchdog", + .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, +}; + +static const struct watchdog_ops max313xx_watchdog_ops = { + .owner = THIS_MODULE, + .start = max313xx_wdt_start, + .stop = max313xx_wdt_stop, + .ping = max313xx_wdt_ping, + .set_timeout = max313xx_wdt_set_timeout, + .get_timeleft = max313xx_wdt_get_timeleft, +}; + +/* Some devices require initialization */ +static int max313xx_init(struct max313xx *rtc) +{ + switch (rtc->id) { + case ID_MAX31341: + case ID_MAX31342: + return regmap_update_bits(rtc->regmap, MAX3134X_CFG_REG, + MAX3134X_CFG_INIT_MASK, + MAX3134X_CFG_INIT_VALUE); + default: + return 0; + } +} + +static int max313xx_clkout_register(struct device *dev) +{ + struct max313xx *rtc = dev_get_drvdata(dev); + int ret; + + if (!device_property_present(dev, "#clock-cells")) + return 0; + + max313xx_clk_init.name = rtc->chip->clkout_name; + device_property_read_string(dev, "clock-output-names", + &max313xx_clk_init.name); + rtc->clkout.init = &max313xx_clk_init; + + ret = devm_clk_hw_register(dev, &rtc->clkout); + if (ret) + return dev_err_probe(dev, ret, "cannot register clock\n"); + + return of_clk_add_provider(dev->of_node, of_clk_src_simple_get, + rtc->clkout.clk); +} + +static int max313xx_trickle_charger_setup(struct device *dev) +{ + struct max313xx *rtc = dev_get_drvdata(dev); + bool diode_disable; + int index, reg; + u32 ohms = 0; + int ret; + + device_property_read_u32(dev, "trickle-resistor-ohms", &ohms); + if (!ohms) + return 0; + + diode_disable = device_property_read_bool(dev, "trickle-diode-disable"); + + if (!rtc->chip->trickle_reg) { + dev_warn(dev, "device does not have trickle charger\n"); + return 0; + } + + index = find_closest(ohms, max313xx_trickle_ohms, + ARRAY_SIZE(max313xx_trickle_ohms)) + 1; + + switch (rtc->id) { + case ID_MAX31329: + reg = FIELD_PREP(MAX31329_TRICKLE_ENABLE_BIT, 1) | + FIELD_PREP(MAX31329_43_TRICKLE_RES_MASK, index) | + FIELD_PREP(MAX31329_43_TRICKLE_DIODE_EN, !diode_disable); + break; + case ID_MAX31331: + case ID_MAX31334: + reg = FIELD_PREP(MAX3133X_TRICKLE_ENABLE_BIT, 1) | + FIELD_PREP(MAX3133X_TRICKLE_DIODE_EN, !diode_disable) | + FIELD_PREP(MAX3133X_TRICKLE_RES_MASK, index); + break; + case ID_MAX31341: + if (index == 1) + index = 0; + reg = FIELD_PREP(MAX31341_TRICKLE_ENABLE_BIT, 1) | + FIELD_PREP(MAX31341_TRICKLE_DIODE_EN, !diode_disable) | + FIELD_PREP(MAX31341_TRICKLE_RES_MASK, index); + + ret = regmap_set_bits(rtc->regmap, MAX31341_POWER_MGMT_REG, + MAX31341_POWER_MGMT_TRICKLE_BIT); + if (ret) + return ret; + + break; + case ID_MAX31343: + reg = FIELD_PREP(MAX31329_43_TRICKLE_RES_MASK, index) | + FIELD_PREP(MAX31329_43_TRICKLE_DIODE_EN, !diode_disable) | + FIELD_PREP(MAX31343_TRICKLE_ENABLE_MASK, + MAX31343_TRICKLE_ENABLE_CODE); + break; + default: + return -EOPNOTSUPP; + } + + return regmap_write(rtc->regmap, rtc->chip->trickle_reg, reg); +} + +static int max313xx_find_clkin_freq_index(struct clk *clk) +{ + unsigned long rate = clk_get_rate(clk); + int freq; + int i; + + i = find_closest(rate, max313xx_clkin_freq, + ARRAY_SIZE(max313xx_clkin_freq)); + if (max313xx_clkin_freq[i] == rate) + return i; + + for (i = ARRAY_SIZE(max313xx_clkin_freq) - 1; i >= 0; i--) { + freq = max313xx_clkin_freq[i]; + if (freq == clk_round_rate(clk, freq)) + return i; + } + + /* supplied clock cannot produce one of desired frequency rate */ + return -ENODEV; +} + +static int max313xx_clkin_init(struct device *dev) +{ + struct max313xx *rtc = dev_get_drvdata(dev); + int rate; + int ret; + + rtc->clkin = devm_clk_get_enabled(dev, NULL); + if (IS_ERR(rtc->clkin)) { + if (PTR_ERR(rtc->clkin) == -ENOENT) + rtc->clkin = NULL; + else + return dev_err_probe(dev, PTR_ERR(rtc->clkin), + "error while clkin setup\n"); + } + + if (!rtc->clkin) { + switch (rtc->id) { + case ID_MAX31329: + return regmap_clear_bits(rtc->regmap, + MAX31329_CONFIG2_REG, + MAX31329_CONFIG2_CLKIN_EN); + case ID_MAX31341: + case ID_MAX31342: + return regmap_clear_bits(rtc->regmap, + MAX31341_42_CONFIG1_REG, + MAX31341_42_CONFIG1_CLKIN_EN); + default: + return 0; + } + } + + rate = max313xx_find_clkin_freq_index(rtc->clkin); + if (rate < 0) + return dev_err_probe(dev, rate, + "clkin cannot produce required frequency\n"); + + ret = clk_set_rate(rtc->clkin, max313xx_clkin_freq[rate]); + if (ret) + return ret; + + switch (rtc->id) { + case ID_MAX31329: + ret = regmap_update_bits(rtc->regmap, MAX31329_CONFIG2_REG, + MAX31329_CONFIG2_CLKIN_FREQ, rate); + if (ret) + return ret; + + return regmap_set_bits(rtc->regmap, MAX31329_CONFIG2_REG, + MAX31329_CONFIG2_CLKIN_EN); + case ID_MAX31341: + case ID_MAX31342: + ret = regmap_update_bits(rtc->regmap, MAX31341_42_CONFIG1_REG, + MAX31341_42_CONFIG1_CLKIN_FREQ, + FIELD_PREP(MAX31341_42_CONFIG1_CLKIN_FREQ, rate)); + if (ret) + return ret; + + return regmap_set_bits(rtc->regmap, MAX31341_42_CONFIG1_REG, + MAX31341_42_CONFIG1_CLKIN_EN); + default: + rtc->clkin = NULL; + dev_warn(dev, "device does not have clock input\n"); + return 0; + } +} + +static int max313xx_irq_init(struct device *dev, const char *devname) +{ + struct max313xx *rtc = dev_get_drvdata(dev); + bool wakeup; + int ret; + + rtc->irq = rtc->irqs[0]; + + switch (rtc->id) { + case ID_MAX31328: + /* max31328 sqw ant int pin is shared */ + if (rtc->id == ID_MAX31328 && rtc->irq > 0 && rtc->clkout.clk) + return dev_err_probe(dev, -EOPNOTSUPP, + "cannot have both sqw clock output and irq enabled"); + + break; + case ID_MAX31331: + case ID_MAX31334: + if (rtc->clkout.clk) { + /* clockout needs to be enabled for using INTA pin */ + ret = clk_prepare_enable(rtc->clkout.clk); + if (ret) + return dev_err_probe(dev, ret, + "cannot enable clkout\n"); + } else { + rtc->irq = rtc->irqs[1]; + } + break; + default: + if (rtc->clkin) { + rtc->irq = rtc->irqs[1]; + + /* wrong interrupt specified */ + if (rtc->irqs[0] > 0 && rtc->irqs[1] <= 0) + dev_warn(dev, "INTA is specified but INTB required for irq when clkin is enabled\n"); + + if (rtc->clkout.clk && rtc->irq > 0) + return dev_err_probe(dev, -EOPNOTSUPP, + "irq not possible when both clkin and clkout are configured\n"); + + if (rtc->irq <= 0) + break; + + /* clkout needs to be disabled for using INTB pin */ + if (rtc->chip->clkout->en_invert) + ret = regmap_set_bits(rtc->regmap, + rtc->chip->clkout->reg, + rtc->chip->clkout->en_bit); + else + ret = regmap_clear_bits(rtc->regmap, + rtc->chip->clkout->reg, + rtc->chip->clkout->en_bit); + + if (ret) + return ret; + } + break; + } + + if (rtc->irq > 0) { + ret = devm_request_threaded_irq(dev, rtc->irq, NULL, + &max313xx_irq, IRQF_ONESHOT, + devname, rtc); + if (ret) + return ret; + + wakeup = device_property_read_bool(dev, "wakeup-source"); + return device_init_wakeup(dev, wakeup); + } + + __clear_bit(RTC_FEATURE_ALARM, rtc->rtc->features); + + return 0; +} + +static int max313xx_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct device *dev = &client->dev; + struct max313xx *max313xx; + struct device *hwmon; + const void *match; + int ret; + + max313xx = devm_kzalloc(&client->dev, sizeof(*max313xx), GFP_KERNEL); + if (!max313xx) + return -ENOMEM; + + dev_set_drvdata(&client->dev, max313xx); + + max313xx->regmap = devm_regmap_init_i2c(client, ®map_config); + if (IS_ERR(max313xx->regmap)) { + return dev_err_probe(dev, PTR_ERR(max313xx->regmap), + "regmap init failed\n"); + } + + i2c_set_clientdata(client, max313xx); + + match = device_get_match_data(dev); + if (match) + max313xx->id = (enum max313xx_ids)match; + else if (id) + max313xx->id = id->driver_data; + else + return -ENODEV; + + max313xx->chip = &chip[max313xx->id]; + + ret = max313xx_init(max313xx); + if (ret) + return ret; + + ret = max313xx_convert_24hr(max313xx); + if (ret) + return ret; + + max313xx->rtc = devm_rtc_allocate_device(dev); + if (IS_ERR(max313xx->rtc)) + return PTR_ERR(max313xx->rtc); + + max313xx->rtc->ops = &max3133x_rtc_ops; + max313xx->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; + max313xx->rtc->range_max = RTC_TIMESTAMP_END_2199; + + ret = devm_rtc_register_device(max313xx->rtc); + if (ret) + return ret; + + switch (max313xx->id) { + case ID_MAX31328: + case ID_MAX31343: + max313xx->irqs[0] = client->irq; + break; + default: + max313xx->irqs[0] = fwnode_irq_get_byname(dev_fwnode(dev), "INTA"); + max313xx->irqs[1] = fwnode_irq_get_byname(dev_fwnode(dev), "INTB"); + if (max313xx->irqs[0] <= 0 && max313xx->irqs[1] <= 0 && client->irq) + return dev_err_probe(dev, -ENOENT, + "interrupt requested but no interrupt name specified\n"); + + break; + } + + ret = max313xx_clkout_register(dev); + if (ret) + return ret; + + ret = max313xx_clkin_init(dev); + if (ret) + return ret; + + /* IRQ wiring depends on the clock configuration so parse them first */ + ret = max313xx_irq_init(dev, client->name); + if (ret) + return ret; + + if (max313xx->chip->ram_size) { + max313xx_nvmem_cfg.size = max313xx->chip->ram_size; + max313xx_nvmem_cfg.priv = max313xx; + + ret = devm_rtc_nvmem_register(max313xx->rtc, &max313xx_nvmem_cfg); + if (ret) + dev_warn(dev, "cannot register rtc nvmem\n"); + } + + if (max313xx->chip->temp_reg) { + hwmon = devm_hwmon_device_register_with_info(dev, client->name, + max313xx, + &max313xx_chip_info, + NULL); + if (IS_ERR(hwmon)) + dev_warn(dev, "cannot register hwmon device: %li\n", + PTR_ERR(hwmon)); + } + + ret = max313xx_trickle_charger_setup(dev); + if (ret) + return ret; + + if (max313xx->chip->timer_cfg_reg) { + max313xx->wdd.parent = dev; + max313xx->wdd.info = &max313xx_wdt_info; + max313xx->wdd.ops = &max313xx_watchdog_ops; + max313xx->wdd.status = WATCHDOG_NOWAYOUT_INIT_STATUS; + max313xx->wdd.min_timeout = 2; + + switch (max313xx->id) { + case ID_MAX31334: + /* 16-bit, 16Hz */ + max313xx->wdd.max_timeout = 4095; + break; + default: + /* 8-bit, 16Hz */ + max313xx->wdd.max_timeout = 15; + } + + watchdog_set_drvdata(&max313xx->wdd, max313xx); + + /* Set timer frequency to minimum possible value */ + ret = regmap_write(max313xx->regmap, max313xx->chip->timer_cfg_reg, + FIELD_PREP(MAX313XX_TMR_CFG_FREQ_MASK, + MAX313XX_TMR_CFG_FREQ_16HZ)); + if (ret) { + dev_warn(dev, "cannot set timer frequency\n"); + } else { + ret = devm_watchdog_register_device(dev, &max313xx->wdd); + if (ret) + dev_warn(dev, "cannot register watchdog dev\n"); + } + } + + return 0; +} + +static const struct of_device_id max313xx_of_id[] = { + { .compatible = "adi,max31328", .data = (void *)ID_MAX31328 }, + { .compatible = "adi,max31329", .data = (void *)ID_MAX31329 }, + { .compatible = "adi,max31331", .data = (void *)ID_MAX31331 }, + { .compatible = "adi,max31334", .data = (void *)ID_MAX31334 }, + { .compatible = "adi,max31341", .data = (void *)ID_MAX31341 }, + { .compatible = "adi,max31342", .data = (void *)ID_MAX31342 }, + { .compatible = "adi,max31343", .data = (void *)ID_MAX31343 }, + { } +}; +MODULE_DEVICE_TABLE(of, max313xx_of_id); + +static const struct i2c_device_id max313xx_id[] = { + { "max31328", ID_MAX31328 }, + { "max31329", ID_MAX31329 }, + { "max31331", ID_MAX31331 }, + { "max31334", ID_MAX31334 }, + { "max31341", ID_MAX31341 }, + { "max31342", ID_MAX31342 }, + { "max31343", ID_MAX31343 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, max313xx_id); + +static struct i2c_driver max313xx_driver = { + .driver = { + .name = "rtc-max313xx", + .of_match_table = max313xx_of_id, + }, + .probe = max313xx_probe, + .id_table = max313xx_id, +}; +module_i2c_driver(max313xx_driver); + +MODULE_DESCRIPTION("Analog Devices MAX313XX RTCs"); +MODULE_AUTHOR("Zeynep Arslanbenzer <Zeynep.Arslanbenzer@xxxxxxxxxx>"); +MODULE_AUTHOR("Ibrahim Tilki <Ibrahim.Tilki@xxxxxxxxxx>"); +MODULE_SOFTDEP("pre: regmap-i2c"); +MODULE_LICENSE("GPL"); +MODULE_VERSION("1.0"); -- 2.25.1