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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/reset/reset-simple.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/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);