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authorNiklas Cassel <cassel@kernel.org>2026-09-16 15:00:32 +0200
committerNiklas Cassel <cassel@kernel.org>2026-09-16 16:18:00 +0200
commit8d836581f9b1f57ceaa2b47654754ef1260b410b (patch)
tree1dbd4d0dfb99c2e238356cbe947e5b0be3e3a571 /drivers/rtc/rtc-macsmc.c
downloadlinux-stable-8d836581f9b1f57ceaa2b47654754ef1260b410b.tar.gz
linux-stable-8d836581f9b1f57ceaa2b47654754ef1260b410b.zip
ata: libata-scsi: fix ata_dsm_trim_pages() kernel-docgrafted
make htmldocs fails with: Documentation/driver-api/libata:604: ./drivers/ata/libata-scsi.c:2301: ERROR: Unexpected indentation. [docutils] The Return: section of ata_dsm_trim_pages() ends its first sentence with a colon and continues with an indented bullet list. reStructuredText requires a blank line before an indented block, so docutils chokes on the list. Simply adding the missing blank line does not work either: Return: is a kernel-doc "special section", which is terminated by the first blank line, so the bullet list would end up in the Description section, detached from the sentence introducing it. Spell the two bounds out as prose instead, so that the Return: section stays self-contained. Documentation-only change. Fixes: e64e6b5dc867 ("ata: libata-scsi: scale DSM TRIM payload by MAX PAGES PER DSM COMMAND") Reported-by: Thomas Huth <thuth@redhat.com> Closes: https://lore.kernel.org/linux-ide/b0a0b8e8-cc4f-4c7b-8bc5-fee0712d405a@redhat.com/ Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Thomas Huth <thuth@redhat.com> Link: https://lore.kernel.org/r/20260916130031.29990-2-cassel@kernel.org Signed-off-by: Niklas Cassel <cassel@kernel.org>
Diffstat (limited to 'drivers/rtc/rtc-macsmc.c')
-rw-r--r--drivers/rtc/rtc-macsmc.c140
1 files changed, 140 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-macsmc.c b/drivers/rtc/rtc-macsmc.c
new file mode 100644
index 000000000..8fe883066
--- /dev/null
+++ b/drivers/rtc/rtc-macsmc.c
@@ -0,0 +1,140 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/*
+ * Apple SMC RTC driver
+ * Copyright The Asahi Linux Contributors
+ */
+
+#include <linux/bitops.h>
+#include <linux/mfd/macsmc.h>
+#include <linux/module.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+
+/* 48-bit RTC */
+#define RTC_BYTES 6
+#define RTC_BITS (8 * RTC_BYTES)
+
+/* 32768 Hz clock */
+#define RTC_SEC_SHIFT 15
+
+struct macsmc_rtc {
+ struct device *dev;
+ struct apple_smc *smc;
+ struct rtc_device *rtc_dev;
+ struct nvmem_cell *rtc_offset;
+};
+
+static int macsmc_rtc_get_time(struct device *dev, struct rtc_time *tm)
+{
+ struct macsmc_rtc *rtc = dev_get_drvdata(dev);
+ u64 ctr = 0, off = 0;
+ time64_t now;
+ void *p_off;
+ size_t len;
+ int ret;
+
+ ret = apple_smc_read(rtc->smc, SMC_KEY(CLKM), &ctr, RTC_BYTES);
+ if (ret < 0)
+ return ret;
+ if (ret != RTC_BYTES)
+ return -EIO;
+
+ p_off = nvmem_cell_read(rtc->rtc_offset, &len);
+ if (IS_ERR(p_off))
+ return PTR_ERR(p_off);
+ if (len < RTC_BYTES) {
+ kfree(p_off);
+ return -EIO;
+ }
+
+ memcpy(&off, p_off, RTC_BYTES);
+ kfree(p_off);
+
+ /* Sign extend from 48 to 64 bits, then arithmetic shift right 15 bits to get seconds */
+ now = sign_extend64(ctr + off, RTC_BITS - 1) >> RTC_SEC_SHIFT;
+ rtc_time64_to_tm(now, tm);
+
+ return ret;
+}
+
+static int macsmc_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct macsmc_rtc *rtc = dev_get_drvdata(dev);
+ u64 ctr = 0, off = 0;
+ int ret;
+
+ ret = apple_smc_read(rtc->smc, SMC_KEY(CLKM), &ctr, RTC_BYTES);
+ if (ret < 0)
+ return ret;
+ if (ret != RTC_BYTES)
+ return -EIO;
+
+ /* This sets the offset such that the set second begins now */
+ off = (rtc_tm_to_time64(tm) << RTC_SEC_SHIFT) - ctr;
+ return nvmem_cell_write(rtc->rtc_offset, &off, RTC_BYTES);
+}
+
+static const struct rtc_class_ops macsmc_rtc_ops = {
+ .read_time = macsmc_rtc_get_time,
+ .set_time = macsmc_rtc_set_time,
+};
+
+static int macsmc_rtc_probe(struct platform_device *pdev)
+{
+ struct apple_smc *smc = dev_get_drvdata(pdev->dev.parent);
+ struct macsmc_rtc *rtc;
+
+ /*
+ * MFD will probe this device even without a node in the device tree,
+ * thus bail out early if the SMC on the current machines does not
+ * support RTC and has no node in the device tree.
+ */
+ if (!pdev->dev.of_node)
+ return -ENODEV;
+
+ rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
+ if (!rtc)
+ return -ENOMEM;
+
+ rtc->dev = &pdev->dev;
+ rtc->smc = smc;
+
+ rtc->rtc_offset = devm_nvmem_cell_get(&pdev->dev, "rtc_offset");
+ if (IS_ERR(rtc->rtc_offset))
+ return dev_err_probe(&pdev->dev, PTR_ERR(rtc->rtc_offset),
+ "Failed to get rtc_offset NVMEM cell\n");
+
+ rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(rtc->rtc_dev))
+ return PTR_ERR(rtc->rtc_dev);
+
+ rtc->rtc_dev->ops = &macsmc_rtc_ops;
+ rtc->rtc_dev->range_min = S64_MIN >> (RTC_SEC_SHIFT + (64 - RTC_BITS));
+ rtc->rtc_dev->range_max = S64_MAX >> (RTC_SEC_SHIFT + (64 - RTC_BITS));
+
+ platform_set_drvdata(pdev, rtc);
+
+ return devm_rtc_register_device(rtc->rtc_dev);
+}
+
+static const struct of_device_id macsmc_rtc_of_table[] = {
+ { .compatible = "apple,smc-rtc", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, macsmc_rtc_of_table);
+
+static struct platform_driver macsmc_rtc_driver = {
+ .driver = {
+ .name = "macsmc-rtc",
+ .of_match_table = macsmc_rtc_of_table,
+ },
+ .probe = macsmc_rtc_probe,
+};
+module_platform_driver(macsmc_rtc_driver);
+
+MODULE_LICENSE("Dual MIT/GPL");
+MODULE_DESCRIPTION("Apple SMC RTC driver");
+MODULE_AUTHOR("Hector Martin <marcan@marcan.st>");