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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/rtc/rtc-rx8581.c
downloadlinux-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-rx8581.c')
-rw-r--r--drivers/rtc/rtc-rx8581.c322
1 files changed, 322 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-rx8581.c b/drivers/rtc/rtc-rx8581.c
new file mode 100644
index 000000000..cf4dab94c
--- /dev/null
+++ b/drivers/rtc/rtc-rx8581.c
@@ -0,0 +1,322 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * An I2C driver for the Epson RX8581 RTC
+ *
+ * Author: Martyn Welch <martyn.welch@ge.com>
+ * Copyright 2008 GE Intelligent Platforms Embedded Systems, Inc.
+ *
+ * Based on: rtc-pcf8563.c (An I2C driver for the Philips PCF8563 RTC)
+ * Copyright 2005-06 Tower Technologies
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/bcd.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+#include <linux/log2.h>
+
+#define RX8581_REG_SC 0x00 /* Second in BCD */
+#define RX8581_REG_MN 0x01 /* Minute in BCD */
+#define RX8581_REG_HR 0x02 /* Hour in BCD */
+#define RX8581_REG_DW 0x03 /* Day of Week */
+#define RX8581_REG_DM 0x04 /* Day of Month in BCD */
+#define RX8581_REG_MO 0x05 /* Month in BCD */
+#define RX8581_REG_YR 0x06 /* Year in BCD */
+#define RX8581_REG_RAM 0x07 /* RAM */
+#define RX8581_REG_AMN 0x08 /* Alarm Min in BCD*/
+#define RX8581_REG_AHR 0x09 /* Alarm Hour in BCD */
+#define RX8581_REG_ADM 0x0A
+#define RX8581_REG_ADW 0x0A
+#define RX8581_REG_TMR0 0x0B
+#define RX8581_REG_TMR1 0x0C
+#define RX8581_REG_EXT 0x0D /* Extension Register */
+#define RX8581_REG_FLAG 0x0E /* Flag Register */
+#define RX8581_REG_CTRL 0x0F /* Control Register */
+
+
+/* Flag Register bit definitions */
+#define RX8581_FLAG_UF 0x20 /* Update */
+#define RX8581_FLAG_TF 0x10 /* Timer */
+#define RX8581_FLAG_AF 0x08 /* Alarm */
+#define RX8581_FLAG_VLF 0x02 /* Voltage Low */
+
+/* Control Register bit definitions */
+#define RX8581_CTRL_UIE 0x20 /* Update Interrupt Enable */
+#define RX8581_CTRL_TIE 0x10 /* Timer Interrupt Enable */
+#define RX8581_CTRL_AIE 0x08 /* Alarm Interrupt Enable */
+#define RX8581_CTRL_STOP 0x02 /* STOP bit */
+#define RX8581_CTRL_RESET 0x01 /* RESET bit */
+
+#define RX8571_USER_RAM 0x10
+#define RX8571_NVRAM_SIZE 0x10
+
+struct rx85x1_config {
+ struct regmap_config regmap;
+ unsigned int num_nvram;
+};
+
+/*
+ * In the routines that deal directly with the rx8581 hardware, we use
+ * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
+ */
+static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ unsigned char date[7];
+ unsigned int data;
+ int err;
+ struct regmap *regmap = i2c_get_clientdata(client);
+
+ /* First we ensure that the "update flag" is not set, we read the
+ * time and date then re-read the "update flag". If the update flag
+ * has been set, we know that the time has changed during the read so
+ * we repeat the whole process again.
+ */
+ err = regmap_read(regmap, RX8581_REG_FLAG, &data);
+ if (err < 0)
+ return err;
+
+ if (data & RX8581_FLAG_VLF) {
+ dev_warn(dev,
+ "low voltage detected, date/time is not reliable.\n");
+ return -EINVAL;
+ }
+
+ do {
+ /* If update flag set, clear it */
+ if (data & RX8581_FLAG_UF) {
+ err = regmap_write(regmap, RX8581_REG_FLAG,
+ data & ~RX8581_FLAG_UF);
+ if (err < 0)
+ return err;
+ }
+
+ /* Now read time and date */
+ err = regmap_bulk_read(regmap, RX8581_REG_SC, date,
+ sizeof(date));
+ if (err < 0)
+ return err;
+
+ /* Check flag register */
+ err = regmap_read(regmap, RX8581_REG_FLAG, &data);
+ if (err < 0)
+ return err;
+ } while (data & RX8581_FLAG_UF);
+
+ dev_dbg(dev, "%s: raw data is sec=%02x, min=%02x, hr=%02x, "
+ "wday=%02x, mday=%02x, mon=%02x, year=%02x\n",
+ __func__,
+ date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
+
+ tm->tm_sec = bcd2bin(date[RX8581_REG_SC] & 0x7F);
+ tm->tm_min = bcd2bin(date[RX8581_REG_MN] & 0x7F);
+ tm->tm_hour = bcd2bin(date[RX8581_REG_HR] & 0x3F); /* rtc hr 0-23 */
+ tm->tm_wday = ilog2(date[RX8581_REG_DW] & 0x7F);
+ tm->tm_mday = bcd2bin(date[RX8581_REG_DM] & 0x3F);
+ tm->tm_mon = bcd2bin(date[RX8581_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
+ tm->tm_year = bcd2bin(date[RX8581_REG_YR]) + 100;
+
+ dev_dbg(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 rx8581_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ int err;
+ unsigned char buf[7];
+ struct regmap *regmap = i2c_get_clientdata(client);
+
+ dev_dbg(dev, "%s: 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);
+
+ /* hours, minutes and seconds */
+ buf[RX8581_REG_SC] = bin2bcd(tm->tm_sec);
+ buf[RX8581_REG_MN] = bin2bcd(tm->tm_min);
+ buf[RX8581_REG_HR] = bin2bcd(tm->tm_hour);
+
+ buf[RX8581_REG_DM] = bin2bcd(tm->tm_mday);
+
+ /* month, 1 - 12 */
+ buf[RX8581_REG_MO] = bin2bcd(tm->tm_mon + 1);
+
+ /* year and century */
+ buf[RX8581_REG_YR] = bin2bcd(tm->tm_year - 100);
+ buf[RX8581_REG_DW] = (0x1 << tm->tm_wday);
+
+ /* Stop the clock */
+ err = regmap_update_bits(regmap, RX8581_REG_CTRL,
+ RX8581_CTRL_STOP, RX8581_CTRL_STOP);
+ if (err < 0)
+ return err;
+
+ /* write register's data */
+ err = regmap_bulk_write(regmap, RX8581_REG_SC, buf, sizeof(buf));
+ if (err < 0)
+ return err;
+
+ /* get VLF and clear it */
+ err = regmap_update_bits(regmap, RX8581_REG_FLAG, RX8581_FLAG_VLF, 0);
+ if (err < 0)
+ return err;
+
+ /* Restart the clock */
+ return regmap_update_bits(regmap, RX8581_REG_CTRL,
+ RX8581_CTRL_STOP, 0);
+}
+
+static const struct rtc_class_ops rx8581_rtc_ops = {
+ .read_time = rx8581_rtc_read_time,
+ .set_time = rx8581_rtc_set_time,
+};
+
+static int rx8571_nvram_read(void *priv, unsigned int offset, void *val,
+ size_t bytes)
+{
+ struct regmap *regmap = priv;
+
+ return regmap_bulk_read(regmap, RX8571_USER_RAM + offset, val, bytes);
+}
+
+static int rx8571_nvram_write(void *priv, unsigned int offset, void *val,
+ size_t bytes)
+{
+ struct regmap *regmap = priv;
+
+ return regmap_bulk_write(regmap, RX8571_USER_RAM + offset, val, bytes);
+}
+
+static int rx85x1_nvram_read(void *priv, unsigned int offset, void *val,
+ size_t bytes)
+{
+ struct regmap *regmap = priv;
+ unsigned int tmp_val;
+ int ret;
+
+ ret = regmap_read(regmap, RX8581_REG_RAM, &tmp_val);
+ (*(unsigned char *)val) = (unsigned char) tmp_val;
+
+ return ret;
+}
+
+static int rx85x1_nvram_write(void *priv, unsigned int offset, void *val,
+ size_t bytes)
+{
+ struct regmap *regmap = priv;
+ unsigned char tmp_val;
+
+ tmp_val = *((unsigned char *)val);
+ return regmap_write(regmap, RX8581_REG_RAM, (unsigned int)tmp_val);
+}
+
+static const struct rx85x1_config rx8581_config = {
+ .regmap = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = 0xf,
+ },
+ .num_nvram = 1
+};
+
+static const struct rx85x1_config rx8571_config = {
+ .regmap = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = 0x1f,
+ },
+ .num_nvram = 2
+};
+
+static int rx8581_probe(struct i2c_client *client)
+{
+ struct regmap *regmap;
+ const struct rx85x1_config *config = &rx8581_config;
+ const void *data = of_device_get_match_data(&client->dev);
+ struct rtc_device *rtc;
+ static struct nvmem_config nvmem_cfg[] = {
+ {
+ .name = "rx85x1-",
+ .word_size = 1,
+ .stride = 1,
+ .size = 1,
+ .reg_read = rx85x1_nvram_read,
+ .reg_write = rx85x1_nvram_write,
+ }, {
+ .name = "rx8571-",
+ .word_size = 1,
+ .stride = 1,
+ .size = RX8571_NVRAM_SIZE,
+ .reg_read = rx8571_nvram_read,
+ .reg_write = rx8571_nvram_write,
+ },
+ };
+ int ret, i;
+
+ dev_dbg(&client->dev, "%s\n", __func__);
+
+ if (data)
+ config = data;
+
+ regmap = devm_regmap_init_i2c(client, &config->regmap);
+ if (IS_ERR(regmap))
+ return PTR_ERR(regmap);
+
+ i2c_set_clientdata(client, regmap);
+
+ rtc = devm_rtc_allocate_device(&client->dev);
+ if (IS_ERR(rtc))
+ return PTR_ERR(rtc);
+
+ rtc->ops = &rx8581_rtc_ops;
+ rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+ rtc->range_max = RTC_TIMESTAMP_END_2099;
+ rtc->start_secs = 0;
+ rtc->set_start_time = true;
+
+ ret = devm_rtc_register_device(rtc);
+
+ for (i = 0; i < config->num_nvram; i++) {
+ nvmem_cfg[i].priv = regmap;
+ devm_rtc_nvmem_register(rtc, &nvmem_cfg[i]);
+ }
+
+ return ret;
+}
+
+static const struct i2c_device_id rx8581_id[] = {
+ { .name = "rx8581" },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, rx8581_id);
+
+static const __maybe_unused struct of_device_id rx8581_of_match[] = {
+ { .compatible = "epson,rx8571", .data = &rx8571_config },
+ { .compatible = "epson,rx8581", .data = &rx8581_config },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rx8581_of_match);
+
+static struct i2c_driver rx8581_driver = {
+ .driver = {
+ .name = "rtc-rx8581",
+ .of_match_table = of_match_ptr(rx8581_of_match),
+ },
+ .probe = rx8581_probe,
+ .id_table = rx8581_id,
+};
+
+module_i2c_driver(rx8581_driver);
+
+MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com>");
+MODULE_DESCRIPTION("Epson RX-8571/RX-8581 RTC driver");
+MODULE_LICENSE("GPL");