Re: [PATCH v5 1/2] drivers: rtc: add max313xx series rtc driver
From: Chris Packham
Date: Sun Apr 23 2023 - 19:28:14 EST
On 24/04/23 10:52, Chris Packham wrote:
> Hi Ibrahim,
>
> On 4/04/23 03:43, Ibrahim Tilki wrote:
>> Adding support for Analog Devices MAX313XX series RTCs.
>>
>> Signed-off-by: Ibrahim Tilki <Ibrahim.Tilki@xxxxxxxxxx>
>> Signed-off-by: Zeynep Arslanbenzer <Zeynep.Arslanbenzer@xxxxxxxxxx>
>
> Just taking this version for a spin on my board with the MAX31331.
> Compared to patchset 3 I'm finding that the RTC isn't actually running
> after it is set. I haven't begun to debug why this might be. I suspect
> it's not being enabled.
>
> Here's the snippet of dts that I'm using (which worked with patchset 3).
>
> i2c@1 {
> rtc@68 {
> compatible = "adi,max31331";
> reg = <0x68>;
> };
> };
>
> And here's an example of it not working
>
> root@x240-26GHXm ~]# date
> Mon Apr 24 10:49:54 UTC 2023
> [root@x240-26GHXm ~]# hwclock -w
> [root@x240-26GHXm ~]# hwclock -r
> Sat Jan 1 00:00:00 2000 0.000000 seconds
>
> And finally a register dump which I'll start looking at shortly
>
> [root@x240-26GHXm ~]# i2cdump -f -y 2 0x68
> No size specified (using byte-data access)
> 0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
> 00: 40 00 01 43 03 04 04 00 00 00 00 01 01 01 00 00 @.?C???....???..
> 10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 ...............?
> 20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> 30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> 40: 00 00 00 00 00 00 00 00 00 ff ff ff ff ff ff ff ................
> 50: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
> 60: 00 00 00 ff ff ff ff ff ff ff ff ff ff ff ff ff ................
> 70: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
> 80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
> 90: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
> a0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
> b0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
> c0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
> d0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
> e0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
> f0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
Doing a bit of debugging I can see that the OSF bit is set in the STATUS
reg and that the SWRST bit is set in the RESET register. This is likely
because builds on this device have been assuming that the RTC is a
DS1340. Manually clearing the reset bit things start working. I haven't
confirmed but I think patchset 3 probably would have failed in this
situation too.
Even though this might be considered operator error I think that the
driver needs to detect OSF and return -EINVAL in max313xx_read_time like
other RTC drivers do. And that max313xx_set_time needs to ensure that
the SWRST bit is cleared. I can whip up a patch to be squashed into your
next revision if that helps.
>
>> ---
>> drivers/rtc/Kconfig | 11 +
>> drivers/rtc/Makefile | 1 +
>> drivers/rtc/rtc-max313xx.c | 1053 ++++++++++++++++++++++++++++++++++++
>> 3 files changed, 1065 insertions(+)
>> create mode 100644 drivers/rtc/rtc-max313xx.c
>>
>> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
>> index 753872408..2160619ed 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 ea445d1eb..880db99be 100644
>> --- a/drivers/rtc/Makefile
>> +++ b/drivers/rtc/Makefile
>> @@ -88,6 +88,7 @@ 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..043528d7d
>> --- /dev/null
>> +++ b/drivers/rtc/rtc-max313xx.c
>> @@ -0,0 +1,1053 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Analog Devices MAX313XX series I2C RTC driver
>> + *
>> + * Copyright 2023 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>
>> +
>> +/* common registers */
>> +#define MAX313XX_INT_ALARM1 BIT(0)
>> +#define MAX313XX_HRS_F_AM_PM BIT(5)
>> +#define MAX313XX_HRS_F_12_24 BIT(6)
>> +#define MAX313XX_MONTH_CENTURY BIT(7)
>> +
>> +#define MAX313XX_TIME_SIZE 0x07
>> +
>> +/* device specific registers */
>> +#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)
>> +#define MAX31341_42_CONFIG1_OSC_DISABLE BIT(3)
>> +#define MAX31341_42_CONFIG1_SWRST BIT(0)
>> +
>> +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 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 clk_hw clkout;
>> + struct clk *clkin;
>> + const struct chip_desc *chip;
>> + 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,
>> + .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,
>> + .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,
>> + .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,
>> + .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,
>> + .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,
>> + .ram_reg = 0x22,
>> + .ram_size = 64,
>> + .temp_reg = 0x1A,
>> + .trickle_reg = 0x19,
>> + .clkout = &max31343_clkout,
>> + .clkout_name = "max31343-clko",
>> + },
>> +};
>> +
>> +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 */
>> + return chip->temp_reg &&
>> + (reg == chip->temp_reg || reg == chip->temp_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_get_hour(u8 hour_reg)
>> +{
>> + int hour;
>> +
>> + /* 24Hr mode */
>> + if (!FIELD_GET(MAX313XX_HRS_F_12_24, hour_reg))
>> + return bcd2bin(hour_reg & 0x3f);
>> +
>> + /* 12Hr mode */
>> + hour = bcd2bin(hour_reg & 0x1f);
>> + if (hour == 12)
>> + hour = 0;
>> +
>> + if (FIELD_GET(MAX313XX_HRS_F_AM_PM, hour_reg))
>> + hour += 12;
>> +
>> + return hour;
>> +}
>> +
>> +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 = max313xx_get_hour(regs[2]);
>> + 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_pre_set_time(struct max313xx *rtc)
>> +{
>> + if (!rtc->clkin)
>> + return 0;
>> +
>> + /* Clkin needs to be disabled before setting time. */
>> + switch (rtc->id) {
>> + case ID_MAX31341:
>> + case ID_MAX31342:
>> + return regmap_clear_bits(rtc->regmap,
>> + MAX31341_42_CONFIG1_REG,
>> + MAX31341_42_CONFIG1_CLKIN_EN);
>> + default:
>> + return 0;
>> + }
>> +}
>> +
>> +static int max313xx_post_set_time(struct max313xx *rtc)
>> +{
>> + int 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:
>> + return 0;
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +static int max313xx_set_time(struct device *dev, struct rtc_time *t)
>> +{
>> + struct max313xx *rtc = dev_get_drvdata(dev);
>> + u8 regs[7];
>> + int ret;
>> +
>> + 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);
>> + regs[6] = bin2bcd(t->tm_year % 100);
>> +
>> + if (t->tm_year >= 200)
>> + regs[5] |= FIELD_PREP(MAX313XX_MONTH_CENTURY, 1);
>> +
>> + ret = max313xx_pre_set_time(rtc);
>> + if (ret)
>> + return ret;
>> +
>> + ret = regmap_bulk_write(rtc->regmap, rtc->chip->sec_reg, regs, 7);
>> + if (ret)
>> + return ret;
>> +
>> + return max313xx_post_set_time(rtc);
>> +}
>> +
>> +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);
>> + 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);
>> + regs[5] = bin2bcd(t->time.tm_year % 100);
>> +
>> + 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, 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_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;
>> + }
>> + break;
>> + 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);
>> + u8 reg[2];
>> + s16 temp;
>> + int ret;
>> +
>> + if (type != hwmon_temp || attr != hwmon_temp_input)
>> + return -EOPNOTSUPP;
>> +
>> + ret = regmap_bulk_read(rtc->regmap, rtc->chip->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_init(struct max313xx *rtc)
>> +{
>> + int ret;
>> +
>> + switch (rtc->id) {
>> + case ID_MAX31341:
>> + case ID_MAX31342:
>> + ret = regmap_clear_bits(rtc->regmap, MAX31341_42_CONFIG1_REG,
>> + MAX31341_42_CONFIG1_OSC_DISABLE);
>> + if (ret)
>> + return ret;
>> +
>> + return regmap_set_bits(rtc->regmap, MAX31341_42_CONFIG1_REG,
>> + MAX31341_42_CONFIG1_SWRST);
>> + 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 devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
>> + &rtc->clkout);
>> +}
>> +
>> +static int max313xx_trickle_charger_setup(struct device *dev)
>> +{
>> + struct max313xx *rtc = dev_get_drvdata(dev);
>> + bool trickle_diode_en;
>> + u32 charger_en = 0;
>> + int index, reg;
>> + u32 ohms = 0;
>> + int ret;
>> +
>> + device_property_read_u32(dev, "aux-voltage-chargeable",
>> &charger_en);
>> + switch (charger_en) {
>> + case 0:
>> + return 0;
>> + case 1:
>> + trickle_diode_en = 0;
>> + break;
>> + case 2:
>> + trickle_diode_en = 1;
>> + break;
>> + default:
>> + return -EINVAL;
>> + }
>> +
>> + device_property_read_u32(dev, "trickle-resistor-ohms", &ohms);
>> +
>> + if (!rtc->chip->trickle_reg)
>> + 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,
>> trickle_diode_en);
>> + break;
>> + case ID_MAX31331:
>> + case ID_MAX31334:
>> + reg = FIELD_PREP(MAX3133X_TRICKLE_ENABLE_BIT, 1) |
>> + FIELD_PREP(MAX3133X_TRICKLE_RES_MASK, index) |
>> + FIELD_PREP(MAX3133X_TRICKLE_DIODE_EN, trickle_diode_en);
>> + break;
>> + case ID_MAX31341:
>> + if (index == 1)
>> + index = 0;
>> +
>> + reg = FIELD_PREP(MAX31341_TRICKLE_ENABLE_BIT, 1) |
>> + FIELD_PREP(MAX31341_TRICKLE_RES_MASK, index) |
>> + FIELD_PREP(MAX31341_TRICKLE_DIODE_EN, trickle_diode_en);
>> +
>> + 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,
>> trickle_diode_en) |
>> + 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);
>> + int ret;
>> +
>> + switch (rtc->id) {
>> + case ID_MAX31328:
>> + break;
>> + case ID_MAX31331:
>> + case ID_MAX31334:
>> + if (rtc->clkout.clk) {
>> + /*
>> + * interrupt muxing depends on clkout so enable clkout
>> + * if configured before requesting interrupt
>> + */
>> + ret = clk_prepare_enable(rtc->clkout.clk);
>> + if (ret)
>> + return dev_err_probe(dev, ret,
>> + "cannot enable clkout\n");
>> + }
>> + break;
>> + default:
>> + if (rtc->clkin) {
>> + 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 interrupt */
>> + 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) {
>> + return devm_request_threaded_irq(dev, rtc->irq, NULL,
>> + &max313xx_irq, IRQF_ONESHOT,
>> + devname, rtc);
>> + } else if (device_property_read_bool(dev, "wakeup-source")) {
>> + clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->rtc->features);
>> + return device_init_wakeup(dev, true);
>> + }
>> +
>> + 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->chip = match;
>> + else if (id)
>> + max313xx->chip = (struct chip_desc *)id->driver_data;
>> + else
>> + return -ENODEV;
>> +
>> + max313xx->id = max313xx->chip - chip;
>> +
>> + ret = max313xx_init(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;
>> +
>> + max313xx->irq = client->irq;
>> +
>> + 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));
>> + }
>> +
>> + return max313xx_trickle_charger_setup(dev);
>> +}
>> +
>> +static const struct of_device_id max313xx_of_id[] = {
>> + { .compatible = "adi,max31328", .data = &chip[ID_MAX31328] },
>> + { .compatible = "adi,max31329", .data = &chip[ID_MAX31329] },
>> + { .compatible = "adi,max31331", .data = &chip[ID_MAX31331] },
>> + { .compatible = "adi,max31334", .data = &chip[ID_MAX31334] },
>> + { .compatible = "adi,max31341", .data = &chip[ID_MAX31341] },
>> + { .compatible = "adi,max31342", .data = &chip[ID_MAX31342] },
>> + { .compatible = "adi,max31343", .data = &chip[ID_MAX31343] },
>> + { }
>> +};
>> +MODULE_DEVICE_TABLE(of, max313xx_of_id);
>> +
>> +static const struct i2c_device_id max313xx_id[] = {
>> + { "max31328", (kernel_ulong_t)&chip[ID_MAX31328] },
>> + { "max31329", (kernel_ulong_t)&chip[ID_MAX31329] },
>> + { "max31331", (kernel_ulong_t)&chip[ID_MAX31331] },
>> + { "max31334", (kernel_ulong_t)&chip[ID_MAX31334] },
>> + { "max31341", (kernel_ulong_t)&chip[ID_MAX31341] },
>> + { "max31342", (kernel_ulong_t)&chip[ID_MAX31342] },
>> + { "max31343", (kernel_ulong_t)&chip[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");