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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/rtc/rtc-s35390a.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/rtc/rtc-s35390a.c')
| -rw-r--r-- | drivers/rtc/rtc-s35390a.c | 541 |
1 files changed, 541 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-s35390a.c b/drivers/rtc/rtc-s35390a.c new file mode 100644 index 000000000..b72eef4fb --- /dev/null +++ b/drivers/rtc/rtc-s35390a.c @@ -0,0 +1,541 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Seiko Instruments S-35390A RTC Driver + * + * Copyright (c) 2007 Byron Bradley + */ + +#include <linux/module.h> +#include <linux/rtc.h> +#include <linux/i2c.h> +#include <linux/bitrev.h> +#include <linux/bcd.h> +#include <linux/slab.h> +#include <linux/delay.h> + +#define S35390A_CMD_STATUS1 0 +#define S35390A_CMD_STATUS2 1 +#define S35390A_CMD_TIME1 2 +#define S35390A_CMD_TIME2 3 +#define S35390A_CMD_INT2_REG1 5 +#define S35390A_CMD_FREE_REG 7 + +#define S35390A_BYTE_YEAR 0 +#define S35390A_BYTE_MONTH 1 +#define S35390A_BYTE_DAY 2 +#define S35390A_BYTE_WDAY 3 +#define S35390A_BYTE_HOURS 4 +#define S35390A_BYTE_MINS 5 +#define S35390A_BYTE_SECS 6 + +#define S35390A_ALRM_BYTE_WDAY 0 +#define S35390A_ALRM_BYTE_HOURS 1 +#define S35390A_ALRM_BYTE_MINS 2 + +/* flags for STATUS1 */ +#define S35390A_FLAG_POC BIT(0) +#define S35390A_FLAG_BLD BIT(1) +#define S35390A_FLAG_INT2 BIT(2) +#define S35390A_FLAG_24H BIT(6) +#define S35390A_FLAG_RESET BIT(7) + +/* flag for STATUS2 */ +#define S35390A_FLAG_TEST BIT(0) + +/* INT2 pin output mode */ +#define S35390A_INT2_MODE_MASK 0x0E +#define S35390A_INT2_MODE_NOINTR 0x00 +#define S35390A_INT2_MODE_ALARM BIT(1) /* INT2AE */ +#define S35390A_INT2_MODE_PMIN_EDG BIT(2) /* INT2ME */ +#define S35390A_INT2_MODE_FREQ BIT(3) /* INT2FE */ +#define S35390A_INT2_MODE_PMIN (BIT(3) | BIT(2)) /* INT2FE | INT2ME */ + +static const struct i2c_device_id s35390a_id[] = { + { .name = "s35390a" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, s35390a_id); + +static const __maybe_unused struct of_device_id s35390a_of_match[] = { + { .compatible = "sii,s35390a" }, + { } +}; +MODULE_DEVICE_TABLE(of, s35390a_of_match); + +struct s35390a { + struct i2c_client *client[8]; + int twentyfourhour; +}; + +static int s35390a_set_reg(struct s35390a *s35390a, int reg, u8 *buf, int len) +{ + struct i2c_client *client = s35390a->client[reg]; + struct i2c_msg msg[] = { + { + .addr = client->addr, + .len = len, + .buf = buf + }, + }; + + if ((i2c_transfer(client->adapter, msg, 1)) != 1) + return -EIO; + + return 0; +} + +static int s35390a_get_reg(struct s35390a *s35390a, int reg, u8 *buf, int len) +{ + struct i2c_client *client = s35390a->client[reg]; + struct i2c_msg msg[] = { + { + .addr = client->addr, + .flags = I2C_M_RD, + .len = len, + .buf = buf + }, + }; + + if ((i2c_transfer(client->adapter, msg, 1)) != 1) + return -EIO; + + return 0; +} + +static int s35390a_init(struct s35390a *s35390a) +{ + u8 buf; + int ret; + unsigned initcount = 0; + + /* + * At least one of POC and BLD are set, so reinitialise chip. Keeping + * this information in the hardware to know later that the time isn't + * valid is unfortunately not possible because POC and BLD are cleared + * on read. So the reset is best done now. + * + * The 24H bit is kept over reset, so set it already here. + */ +initialize: + buf = S35390A_FLAG_RESET | S35390A_FLAG_24H; + ret = s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1); + + if (ret < 0) + return ret; + + ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1); + if (ret < 0) + return ret; + + if (buf & (S35390A_FLAG_POC | S35390A_FLAG_BLD)) { + /* Try up to five times to reset the chip */ + if (initcount < 5) { + ++initcount; + goto initialize; + } else + return -EIO; + } + + return 1; +} + +/* + * Returns <0 on error, 0 if rtc is setup fine and 1 if the chip was reset. + * To keep the information if an irq is pending, pass the value read from + * STATUS1 to the caller. + */ +static int s35390a_read_status(struct s35390a *s35390a, char *status1) +{ + int ret; + + ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, status1, 1); + if (ret < 0) + return ret; + + if (*status1 & S35390A_FLAG_POC) { + /* + * Do not communicate for 0.5 seconds since the power-on + * detection circuit is in operation. + */ + msleep(500); + return 1; + } else if (*status1 & S35390A_FLAG_BLD) + return 1; + /* + * If both POC and BLD are unset everything is fine. + */ + return 0; +} + +static int s35390a_disable_test_mode(struct s35390a *s35390a) +{ + u8 buf[1]; + + if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)) < 0) + return -EIO; + + if (!(buf[0] & S35390A_FLAG_TEST)) + return 0; + + buf[0] &= ~S35390A_FLAG_TEST; + return s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)); +} + +static char s35390a_hr2reg(struct s35390a *s35390a, int hour) +{ + if (s35390a->twentyfourhour) + return bin2bcd(hour); + + if (hour < 12) + return bin2bcd(hour); + + return 0x40 | bin2bcd(hour - 12); +} + +static int s35390a_reg2hr(struct s35390a *s35390a, char reg) +{ + unsigned hour; + + if (s35390a->twentyfourhour) + return bcd2bin(reg & 0x3f); + + hour = bcd2bin(reg & 0x3f); + if (reg & 0x40) + hour += 12; + + return hour; +} + +static int s35390a_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct i2c_client *client = to_i2c_client(dev); + struct s35390a *s35390a = i2c_get_clientdata(client); + int i; + u8 buf[7], status; + + dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d mday=%d, " + "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec, + tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, + tm->tm_wday); + + if (s35390a_read_status(s35390a, &status) == 1) + s35390a_init(s35390a); + + buf[S35390A_BYTE_YEAR] = bin2bcd(tm->tm_year - 100); + buf[S35390A_BYTE_MONTH] = bin2bcd(tm->tm_mon + 1); + buf[S35390A_BYTE_DAY] = bin2bcd(tm->tm_mday); + buf[S35390A_BYTE_WDAY] = bin2bcd(tm->tm_wday); + buf[S35390A_BYTE_HOURS] = s35390a_hr2reg(s35390a, tm->tm_hour); + buf[S35390A_BYTE_MINS] = bin2bcd(tm->tm_min); + buf[S35390A_BYTE_SECS] = bin2bcd(tm->tm_sec); + + /* This chip expects the bits of each byte to be in reverse order */ + for (i = 0; i < 7; ++i) + buf[i] = bitrev8(buf[i]); + + return s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf)); +} + +static int s35390a_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct i2c_client *client = to_i2c_client(dev); + struct s35390a *s35390a = i2c_get_clientdata(client); + u8 buf[7], status; + int i, err; + + if (s35390a_read_status(s35390a, &status) == 1) + return -EINVAL; + + err = s35390a_get_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf)); + if (err < 0) + return err; + + /* This chip returns the bits of each byte in reverse order */ + for (i = 0; i < 7; ++i) + buf[i] = bitrev8(buf[i]); + + tm->tm_sec = bcd2bin(buf[S35390A_BYTE_SECS]); + tm->tm_min = bcd2bin(buf[S35390A_BYTE_MINS]); + tm->tm_hour = s35390a_reg2hr(s35390a, buf[S35390A_BYTE_HOURS]); + tm->tm_wday = bcd2bin(buf[S35390A_BYTE_WDAY]); + tm->tm_mday = bcd2bin(buf[S35390A_BYTE_DAY]); + tm->tm_mon = bcd2bin(buf[S35390A_BYTE_MONTH]) - 1; + tm->tm_year = bcd2bin(buf[S35390A_BYTE_YEAR]) + 100; + + dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, mday=%d, " + "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec, + tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, + tm->tm_wday); + + return 0; +} + +static int s35390a_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + struct i2c_client *client = to_i2c_client(dev); + struct s35390a *s35390a = i2c_get_clientdata(client); + u8 buf[3], sts = 0; + int err, i; + + dev_dbg(&client->dev, "%s: alm is secs=%d, mins=%d, hours=%d mday=%d, "\ + "mon=%d, year=%d, wday=%d\n", __func__, alm->time.tm_sec, + alm->time.tm_min, alm->time.tm_hour, alm->time.tm_mday, + alm->time.tm_mon, alm->time.tm_year, alm->time.tm_wday); + + /* disable interrupt (which deasserts the irq line) */ + err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts)); + if (err < 0) + return err; + + /* clear pending interrupt (in STATUS1 only), if any */ + err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &sts, sizeof(sts)); + if (err < 0) + return err; + + if (alm->enabled) + sts = S35390A_INT2_MODE_ALARM; + else + sts = S35390A_INT2_MODE_NOINTR; + + /* set interrupt mode*/ + err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts)); + if (err < 0) + return err; + + if (alm->time.tm_wday != -1) + buf[S35390A_ALRM_BYTE_WDAY] = bin2bcd(alm->time.tm_wday) | 0x80; + else + buf[S35390A_ALRM_BYTE_WDAY] = 0; + + buf[S35390A_ALRM_BYTE_HOURS] = s35390a_hr2reg(s35390a, + alm->time.tm_hour) | 0x80; + buf[S35390A_ALRM_BYTE_MINS] = bin2bcd(alm->time.tm_min) | 0x80; + + if (alm->time.tm_hour >= 12) + buf[S35390A_ALRM_BYTE_HOURS] |= 0x40; + + for (i = 0; i < 3; ++i) + buf[i] = bitrev8(buf[i]); + + err = s35390a_set_reg(s35390a, S35390A_CMD_INT2_REG1, buf, + sizeof(buf)); + + return err; +} + +static int s35390a_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + struct i2c_client *client = to_i2c_client(dev); + struct s35390a *s35390a = i2c_get_clientdata(client); + u8 buf[3], sts; + int i, err; + + err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts)); + if (err < 0) + return err; + + if ((sts & S35390A_INT2_MODE_MASK) != S35390A_INT2_MODE_ALARM) { + /* + * When the alarm isn't enabled, the register to configure + * the alarm time isn't accessible. + */ + alm->enabled = 0; + return 0; + } else { + alm->enabled = 1; + } + + err = s35390a_get_reg(s35390a, S35390A_CMD_INT2_REG1, buf, sizeof(buf)); + if (err < 0) + return err; + + /* This chip returns the bits of each byte in reverse order */ + for (i = 0; i < 3; ++i) + buf[i] = bitrev8(buf[i]); + + /* + * B0 of the three matching registers is an enable flag. Iff it is set + * the configured value is used for matching. + */ + if (buf[S35390A_ALRM_BYTE_WDAY] & 0x80) + alm->time.tm_wday = + bcd2bin(buf[S35390A_ALRM_BYTE_WDAY] & ~0x80); + + if (buf[S35390A_ALRM_BYTE_HOURS] & 0x80) + alm->time.tm_hour = + s35390a_reg2hr(s35390a, + buf[S35390A_ALRM_BYTE_HOURS] & ~0x80); + + if (buf[S35390A_ALRM_BYTE_MINS] & 0x80) + alm->time.tm_min = bcd2bin(buf[S35390A_ALRM_BYTE_MINS] & ~0x80); + + /* alarm triggers always at s=0 */ + alm->time.tm_sec = 0; + + dev_dbg(&client->dev, "%s: alm is mins=%d, hours=%d, wday=%d\n", + __func__, alm->time.tm_min, alm->time.tm_hour, + alm->time.tm_wday); + + return 0; +} + +static int s35390a_rtc_ioctl(struct device *dev, unsigned int cmd, + unsigned long arg) +{ + struct i2c_client *client = to_i2c_client(dev); + struct s35390a *s35390a = i2c_get_clientdata(client); + u8 sts; + int err; + + switch (cmd) { + case RTC_VL_READ: + /* s35390a_reset set lowvoltage flag and init RTC if needed */ + err = s35390a_read_status(s35390a, &sts); + if (err < 0) + return err; + if (copy_to_user((void __user *)arg, &err, sizeof(int))) + return -EFAULT; + break; + case RTC_VL_CLR: + /* update flag and clear register */ + err = s35390a_init(s35390a); + if (err < 0) + return err; + break; + default: + return -ENOIOCTLCMD; + } + + return 0; +} + +static const struct rtc_class_ops s35390a_rtc_ops = { + .read_time = s35390a_rtc_read_time, + .set_time = s35390a_rtc_set_time, + .set_alarm = s35390a_rtc_set_alarm, + .read_alarm = s35390a_rtc_read_alarm, + .ioctl = s35390a_rtc_ioctl, +}; + +static int s35390a_nvmem_read(void *priv, unsigned int offset, void *val, + size_t bytes) +{ + struct s35390a *s35390a = priv; + + /* The offset is ignored because the NVMEM region is only 1 byte */ + return s35390a_get_reg(s35390a, S35390A_CMD_FREE_REG, val, bytes); +} + +static int s35390a_nvmem_write(void *priv, unsigned int offset, void *val, + size_t bytes) +{ + struct s35390a *s35390a = priv; + + return s35390a_set_reg(s35390a, S35390A_CMD_FREE_REG, val, bytes); +} + +static int s35390a_probe(struct i2c_client *client) +{ + int err, err_read; + unsigned int i; + struct s35390a *s35390a; + struct rtc_device *rtc; + u8 buf, status1; + struct device *dev = &client->dev; + struct nvmem_config nvmem_cfg = { + .name = "s35390a_nvram", + .type = NVMEM_TYPE_BATTERY_BACKED, + .word_size = 1, + .stride = 1, + .size = 1, + .reg_read = s35390a_nvmem_read, + .reg_write = s35390a_nvmem_write, + }; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) + return -ENODEV; + + s35390a = devm_kzalloc(dev, sizeof(struct s35390a), GFP_KERNEL); + if (!s35390a) + return -ENOMEM; + + s35390a->client[0] = client; + i2c_set_clientdata(client, s35390a); + + /* This chip uses multiple addresses, use dummy devices for them */ + for (i = 1; i < 8; ++i) { + s35390a->client[i] = devm_i2c_new_dummy_device(dev, + client->adapter, + client->addr + i); + if (IS_ERR(s35390a->client[i])) { + dev_err(dev, "Address %02x unavailable\n", + client->addr + i); + return PTR_ERR(s35390a->client[i]); + } + } + + rtc = devm_rtc_allocate_device(dev); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + err_read = s35390a_read_status(s35390a, &status1); + if (err_read < 0) { + dev_err(dev, "error resetting chip\n"); + return err_read; + } + + if (status1 & S35390A_FLAG_24H) + s35390a->twentyfourhour = 1; + else + s35390a->twentyfourhour = 0; + + if (status1 & S35390A_FLAG_INT2) { + /* disable alarm (and maybe test mode) */ + buf = 0; + err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &buf, 1); + if (err < 0) { + dev_err(dev, "error disabling alarm"); + return err; + } + } else { + err = s35390a_disable_test_mode(s35390a); + if (err < 0) { + dev_err(dev, "error disabling test mode\n"); + return err; + } + } + + device_set_wakeup_capable(dev, 1); + + rtc->ops = &s35390a_rtc_ops; + rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; + rtc->range_max = RTC_TIMESTAMP_END_2099; + + set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features); + clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features); + + if (status1 & S35390A_FLAG_INT2) + rtc_update_irq(rtc, 1, RTC_AF); + + nvmem_cfg.priv = s35390a; + err = devm_rtc_nvmem_register(rtc, &nvmem_cfg); + if (err) + return err; + + return devm_rtc_register_device(rtc); +} + +static struct i2c_driver s35390a_driver = { + .driver = { + .name = "rtc-s35390a", + .of_match_table = of_match_ptr(s35390a_of_match), + }, + .probe = s35390a_probe, + .id_table = s35390a_id, +}; + +module_i2c_driver(s35390a_driver); + +MODULE_AUTHOR("Byron Bradley <byron.bbradley@gmail.com>"); +MODULE_DESCRIPTION("S35390A RTC driver"); +MODULE_LICENSE("GPL"); |
