summaryrefslogtreecommitdiffstats
path: root/drivers/reset/reset-simple.c
diff options
context:
space:
mode:
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/reset/reset-simple.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/reset/reset-simple.c')
-rw-r--r--drivers/reset/reset-simple.c207
1 files changed, 207 insertions, 0 deletions
diff --git a/drivers/reset/reset-simple.c b/drivers/reset/reset-simple.c
new file mode 100644
index 000000000..79e94ecfe
--- /dev/null
+++ b/drivers/reset/reset-simple.c
@@ -0,0 +1,207 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Simple Reset Controller Driver
+ *
+ * Copyright (C) 2017 Pengutronix, Philipp Zabel <kernel@pengutronix.de>
+ *
+ * Based on Allwinner SoCs Reset Controller driver
+ *
+ * Copyright 2013 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/reset/reset-simple.h>
+#include <linux/spinlock.h>
+
+static inline struct reset_simple_data *
+to_reset_simple_data(struct reset_controller_dev *rcdev)
+{
+ return container_of(rcdev, struct reset_simple_data, rcdev);
+}
+
+static int reset_simple_update(struct reset_controller_dev *rcdev,
+ unsigned long id, bool assert)
+{
+ struct reset_simple_data *data = to_reset_simple_data(rcdev);
+ int reg_width = sizeof(u32);
+ int bank = id / (reg_width * BITS_PER_BYTE);
+ int offset = id % (reg_width * BITS_PER_BYTE);
+ unsigned long flags;
+ u32 reg;
+
+ spin_lock_irqsave(&data->lock, flags);
+
+ reg = readl(data->membase + (bank * reg_width));
+ if (assert ^ data->active_low)
+ reg |= BIT(offset);
+ else
+ reg &= ~BIT(offset);
+ writel(reg, data->membase + (bank * reg_width));
+
+ spin_unlock_irqrestore(&data->lock, flags);
+
+ return 0;
+}
+
+static int reset_simple_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ return reset_simple_update(rcdev, id, true);
+}
+
+static int reset_simple_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ return reset_simple_update(rcdev, id, false);
+}
+
+static int reset_simple_reset(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct reset_simple_data *data = to_reset_simple_data(rcdev);
+ int ret;
+
+ if (!data->reset_us)
+ return -ENOTSUPP;
+
+ ret = reset_simple_assert(rcdev, id);
+ if (ret)
+ return ret;
+
+ usleep_range(data->reset_us, data->reset_us * 2);
+
+ return reset_simple_deassert(rcdev, id);
+}
+
+static int reset_simple_status(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct reset_simple_data *data = to_reset_simple_data(rcdev);
+ int reg_width = sizeof(u32);
+ int bank = id / (reg_width * BITS_PER_BYTE);
+ int offset = id % (reg_width * BITS_PER_BYTE);
+ u32 reg;
+
+ reg = readl(data->membase + (bank * reg_width));
+
+ return !(reg & BIT(offset)) ^ !data->status_active_low;
+}
+
+const struct reset_control_ops reset_simple_ops = {
+ .assert = reset_simple_assert,
+ .deassert = reset_simple_deassert,
+ .reset = reset_simple_reset,
+ .status = reset_simple_status,
+};
+EXPORT_SYMBOL_GPL(reset_simple_ops);
+
+/**
+ * struct reset_simple_devdata - simple reset controller properties
+ * @reg_offset: offset between base address and first reset register.
+ * @nr_resets: number of resets. If not set, default to resource size in bits.
+ * @active_low: if true, bits are cleared to assert the reset. Otherwise, bits
+ * are set to assert the reset.
+ * @status_active_low: if true, bits read back as cleared while the reset is
+ * asserted. Otherwise, bits read back as set while the
+ * reset is asserted.
+ */
+struct reset_simple_devdata {
+ u32 reg_offset;
+ u32 nr_resets;
+ bool active_low;
+ bool status_active_low;
+};
+
+#define SOCFPGA_NR_BANKS 8
+
+static const struct reset_simple_devdata reset_simple_socfpga = {
+ .reg_offset = 0x20,
+ .nr_resets = SOCFPGA_NR_BANKS * 32,
+ .status_active_low = true,
+};
+
+static const struct reset_simple_devdata reset_simple_active_low = {
+ .active_low = true,
+ .status_active_low = true,
+};
+
+static const struct of_device_id reset_simple_dt_ids[] = {
+ { .compatible = "altr,stratix10-rst-mgr",
+ .data = &reset_simple_socfpga },
+ { .compatible = "st,stm32-rcc", },
+ { .compatible = "allwinner,sun6i-a31-clock-reset",
+ .data = &reset_simple_active_low },
+ { .compatible = "zte,zx296718-reset",
+ .data = &reset_simple_active_low },
+ { .compatible = "aspeed,ast2400-lpc-reset" },
+ { .compatible = "aspeed,ast2500-lpc-reset" },
+ { .compatible = "aspeed,ast2600-lpc-reset" },
+ { .compatible = "bitmain,bm1880-reset",
+ .data = &reset_simple_active_low },
+ { .compatible = "brcm,bcm4908-misc-pcie-reset",
+ .data = &reset_simple_active_low },
+ { .compatible = "snps,dw-high-reset" },
+ { .compatible = "snps,dw-low-reset",
+ .data = &reset_simple_active_low },
+ { .compatible = "sophgo,cv1800b-reset",
+ .data = &reset_simple_active_low },
+ { .compatible = "sophgo,sg2042-reset",
+ .data = &reset_simple_active_low },
+ { /* sentinel */ },
+};
+
+static int reset_simple_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ const struct reset_simple_devdata *devdata;
+ struct reset_simple_data *data;
+ void __iomem *membase;
+ struct resource *res;
+ u32 reg_offset = 0;
+
+ devdata = of_device_get_match_data(dev);
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+ if (IS_ERR(membase))
+ return PTR_ERR(membase);
+
+ spin_lock_init(&data->lock);
+ data->membase = membase;
+ data->rcdev.owner = THIS_MODULE;
+ data->rcdev.nr_resets = resource_size(res) * BITS_PER_BYTE;
+ data->rcdev.ops = &reset_simple_ops;
+ data->rcdev.of_node = dev->of_node;
+
+ if (devdata) {
+ reg_offset = devdata->reg_offset;
+ if (devdata->nr_resets)
+ data->rcdev.nr_resets = devdata->nr_resets;
+ data->active_low = devdata->active_low;
+ data->status_active_low = devdata->status_active_low;
+ }
+
+ data->membase += reg_offset;
+
+ return devm_reset_controller_register(dev, &data->rcdev);
+}
+
+static struct platform_driver reset_simple_driver = {
+ .probe = reset_simple_probe,
+ .driver = {
+ .name = "simple-reset",
+ .of_match_table = reset_simple_dt_ids,
+ },
+};
+builtin_platform_driver(reset_simple_driver);