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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-rs5c348.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-rs5c348.c')
-rw-r--r--drivers/rtc/rtc-rs5c348.c215
1 files changed, 215 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-rs5c348.c b/drivers/rtc/rtc-rs5c348.c
new file mode 100644
index 000000000..fec633f80
--- /dev/null
+++ b/drivers/rtc/rtc-rs5c348.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * A SPI driver for the Ricoh RS5C348 RTC
+ *
+ * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
+ *
+ * The board specific init code should provide characteristics of this
+ * device:
+ * Mode 1 (High-Active, Shift-Then-Sample), High Avtive CS
+ */
+
+#include <linux/bcd.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/rtc.h>
+#include <linux/workqueue.h>
+#include <linux/spi/spi.h>
+#include <linux/module.h>
+
+#define RS5C348_REG_SECS 0
+#define RS5C348_REG_MINS 1
+#define RS5C348_REG_HOURS 2
+#define RS5C348_REG_WDAY 3
+#define RS5C348_REG_DAY 4
+#define RS5C348_REG_MONTH 5
+#define RS5C348_REG_YEAR 6
+#define RS5C348_REG_CTL1 14
+#define RS5C348_REG_CTL2 15
+
+#define RS5C348_SECS_MASK 0x7f
+#define RS5C348_MINS_MASK 0x7f
+#define RS5C348_HOURS_MASK 0x3f
+#define RS5C348_WDAY_MASK 0x03
+#define RS5C348_DAY_MASK 0x3f
+#define RS5C348_MONTH_MASK 0x1f
+
+#define RS5C348_BIT_PM 0x20 /* REG_HOURS */
+#define RS5C348_BIT_Y2K 0x80 /* REG_MONTH */
+#define RS5C348_BIT_24H 0x20 /* REG_CTL1 */
+#define RS5C348_BIT_XSTP 0x10 /* REG_CTL2 */
+#define RS5C348_BIT_VDET 0x40 /* REG_CTL2 */
+
+#define RS5C348_CMD_W(addr) (((addr) << 4) | 0x08) /* single write */
+#define RS5C348_CMD_R(addr) (((addr) << 4) | 0x0c) /* single read */
+#define RS5C348_CMD_MW(addr) (((addr) << 4) | 0x00) /* burst write */
+#define RS5C348_CMD_MR(addr) (((addr) << 4) | 0x04) /* burst read */
+
+struct rs5c348_plat_data {
+ struct rtc_device *rtc;
+ int rtc_24h;
+};
+
+static int
+rs5c348_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ struct rs5c348_plat_data *pdata = dev_get_platdata(&spi->dev);
+ u8 txbuf[5+7], *txp;
+ int ret;
+
+ ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_CTL2));
+ if (ret < 0)
+ return ret;
+ if (ret & RS5C348_BIT_XSTP) {
+ txbuf[0] = RS5C348_CMD_W(RS5C348_REG_CTL2);
+ txbuf[1] = 0;
+ ret = spi_write_then_read(spi, txbuf, 2, NULL, 0);
+ if (ret < 0)
+ return ret;
+ }
+
+ /* Transfer 5 bytes before writing SEC. This gives 31us for carry. */
+ txp = txbuf;
+ txbuf[0] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
+ txbuf[1] = 0; /* dummy */
+ txbuf[2] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
+ txbuf[3] = 0; /* dummy */
+ txbuf[4] = RS5C348_CMD_MW(RS5C348_REG_SECS); /* cmd, sec, ... */
+ txp = &txbuf[5];
+ txp[RS5C348_REG_SECS] = bin2bcd(tm->tm_sec);
+ txp[RS5C348_REG_MINS] = bin2bcd(tm->tm_min);
+ if (pdata->rtc_24h) {
+ txp[RS5C348_REG_HOURS] = bin2bcd(tm->tm_hour);
+ } else {
+ /* hour 0 is AM12, noon is PM12 */
+ txp[RS5C348_REG_HOURS] = bin2bcd((tm->tm_hour + 11) % 12 + 1) |
+ (tm->tm_hour >= 12 ? RS5C348_BIT_PM : 0);
+ }
+ txp[RS5C348_REG_WDAY] = bin2bcd(tm->tm_wday);
+ txp[RS5C348_REG_DAY] = bin2bcd(tm->tm_mday);
+ txp[RS5C348_REG_MONTH] = bin2bcd(tm->tm_mon + 1) |
+ (tm->tm_year >= 100 ? RS5C348_BIT_Y2K : 0);
+ txp[RS5C348_REG_YEAR] = bin2bcd(tm->tm_year % 100);
+ /* write in one transfer to avoid data inconsistency */
+ ret = spi_write_then_read(spi, txbuf, sizeof(txbuf), NULL, 0);
+ udelay(62); /* Tcsr 62us */
+ return ret;
+}
+
+static int
+rs5c348_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ struct rs5c348_plat_data *pdata = dev_get_platdata(&spi->dev);
+ u8 txbuf[5], rxbuf[7];
+ int ret;
+
+ ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_CTL2));
+ if (ret < 0)
+ return ret;
+ if (ret & RS5C348_BIT_VDET)
+ dev_warn(&spi->dev, "voltage-low detected.\n");
+ if (ret & RS5C348_BIT_XSTP) {
+ dev_warn(&spi->dev, "oscillator-stop detected.\n");
+ return -EINVAL;
+ }
+
+ /* Transfer 5 byte befores reading SEC. This gives 31us for carry. */
+ txbuf[0] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
+ txbuf[1] = 0; /* dummy */
+ txbuf[2] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
+ txbuf[3] = 0; /* dummy */
+ txbuf[4] = RS5C348_CMD_MR(RS5C348_REG_SECS); /* cmd, sec, ... */
+
+ /* read in one transfer to avoid data inconsistency */
+ ret = spi_write_then_read(spi, txbuf, sizeof(txbuf),
+ rxbuf, sizeof(rxbuf));
+ udelay(62); /* Tcsr 62us */
+ if (ret < 0)
+ return ret;
+
+ tm->tm_sec = bcd2bin(rxbuf[RS5C348_REG_SECS] & RS5C348_SECS_MASK);
+ tm->tm_min = bcd2bin(rxbuf[RS5C348_REG_MINS] & RS5C348_MINS_MASK);
+ tm->tm_hour = bcd2bin(rxbuf[RS5C348_REG_HOURS] & RS5C348_HOURS_MASK);
+ if (!pdata->rtc_24h) {
+ if (rxbuf[RS5C348_REG_HOURS] & RS5C348_BIT_PM) {
+ tm->tm_hour -= 20;
+ tm->tm_hour %= 12;
+ tm->tm_hour += 12;
+ } else
+ tm->tm_hour %= 12;
+ }
+ tm->tm_wday = bcd2bin(rxbuf[RS5C348_REG_WDAY] & RS5C348_WDAY_MASK);
+ tm->tm_mday = bcd2bin(rxbuf[RS5C348_REG_DAY] & RS5C348_DAY_MASK);
+ tm->tm_mon =
+ bcd2bin(rxbuf[RS5C348_REG_MONTH] & RS5C348_MONTH_MASK) - 1;
+ /* year is 1900 + tm->tm_year */
+ tm->tm_year = bcd2bin(rxbuf[RS5C348_REG_YEAR]) +
+ ((rxbuf[RS5C348_REG_MONTH] & RS5C348_BIT_Y2K) ? 100 : 0);
+
+ return 0;
+}
+
+static const struct rtc_class_ops rs5c348_rtc_ops = {
+ .read_time = rs5c348_rtc_read_time,
+ .set_time = rs5c348_rtc_set_time,
+};
+
+static int rs5c348_probe(struct spi_device *spi)
+{
+ int ret;
+ struct rtc_device *rtc;
+ struct rs5c348_plat_data *pdata;
+
+ pdata = devm_kzalloc(&spi->dev, sizeof(struct rs5c348_plat_data),
+ GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+ spi->dev.platform_data = pdata;
+
+ /* Check D7 of SECOND register */
+ ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_SECS));
+ if (ret < 0 || (ret & 0x80)) {
+ dev_err(&spi->dev, "not found.\n");
+ return ret;
+ }
+
+ dev_info(&spi->dev, "spiclk %u KHz.\n",
+ (spi->max_speed_hz + 500) / 1000);
+
+ ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_CTL1));
+ if (ret < 0)
+ return ret;
+ if (ret & RS5C348_BIT_24H)
+ pdata->rtc_24h = 1;
+
+ rtc = devm_rtc_allocate_device(&spi->dev);
+ if (IS_ERR(rtc))
+ return PTR_ERR(rtc);
+
+ pdata->rtc = rtc;
+
+ rtc->ops = &rs5c348_rtc_ops;
+
+ return devm_rtc_register_device(rtc);
+}
+
+static struct spi_driver rs5c348_driver = {
+ .driver = {
+ .name = "rtc-rs5c348",
+ },
+ .probe = rs5c348_probe,
+};
+
+module_spi_driver(rs5c348_driver);
+
+MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
+MODULE_DESCRIPTION("Ricoh RS5C348 RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:rtc-rs5c348");