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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/regulator/stm32-vrefbuf.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/regulator/stm32-vrefbuf.c')
-rw-r--r--drivers/regulator/stm32-vrefbuf.c290
1 files changed, 290 insertions, 0 deletions
diff --git a/drivers/regulator/stm32-vrefbuf.c b/drivers/regulator/stm32-vrefbuf.c
new file mode 100644
index 000000000..9e391206f
--- /dev/null
+++ b/drivers/regulator/stm32-vrefbuf.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) STMicroelectronics 2017
+ *
+ * Author: Fabrice Gasnier <fabrice.gasnier@st.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/pm_runtime.h>
+
+/* STM32 VREFBUF registers */
+#define STM32_VREFBUF_CSR 0x00
+
+/* STM32 VREFBUF CSR bitfields */
+#define STM32_VRS GENMASK(6, 4)
+#define STM32_VRR BIT(3)
+#define STM32_HIZ BIT(1)
+#define STM32_ENVR BIT(0)
+
+#define STM32_VREFBUF_AUTO_SUSPEND_DELAY_MS 10
+
+struct stm32_vrefbuf {
+ void __iomem *base;
+ struct clk *clk;
+ struct device *dev;
+};
+
+static const unsigned int stm32_vrefbuf_voltages[] = {
+ /* Matches resp. VRS = 000b, 001b, 010b, 011b */
+ 2500000, 2048000, 1800000, 1500000,
+};
+
+static int stm32_vrefbuf_enable(struct regulator_dev *rdev)
+{
+ struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
+ u32 val;
+ int ret;
+
+ ret = pm_runtime_resume_and_get(priv->dev);
+ if (ret < 0)
+ return ret;
+
+ val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
+ val = (val & ~STM32_HIZ) | STM32_ENVR;
+ writel_relaxed(val, priv->base + STM32_VREFBUF_CSR);
+
+ /*
+ * Vrefbuf startup time depends on external capacitor: wait here for
+ * VRR to be set. That means output has reached expected value.
+ * ~650us sleep should be enough for caps up to 1.5uF. Use 10ms as
+ * arbitrary timeout.
+ */
+ ret = readl_poll_timeout(priv->base + STM32_VREFBUF_CSR, val,
+ val & STM32_VRR, 650, 10000);
+ if (ret) {
+ dev_err(&rdev->dev, "stm32 vrefbuf timed out!\n");
+ val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
+ val = (val & ~STM32_ENVR) | STM32_HIZ;
+ writel_relaxed(val, priv->base + STM32_VREFBUF_CSR);
+ }
+
+ pm_runtime_put_autosuspend(priv->dev);
+
+ return ret;
+}
+
+static int stm32_vrefbuf_disable(struct regulator_dev *rdev)
+{
+ struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
+ u32 val;
+ int ret;
+
+ ret = pm_runtime_resume_and_get(priv->dev);
+ if (ret < 0)
+ return ret;
+
+ val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
+ val &= ~STM32_ENVR;
+ writel_relaxed(val, priv->base + STM32_VREFBUF_CSR);
+
+ pm_runtime_put_autosuspend(priv->dev);
+
+ return 0;
+}
+
+static int stm32_vrefbuf_is_enabled(struct regulator_dev *rdev)
+{
+ struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
+ int ret;
+
+ ret = pm_runtime_resume_and_get(priv->dev);
+ if (ret < 0)
+ return ret;
+
+ ret = readl_relaxed(priv->base + STM32_VREFBUF_CSR) & STM32_ENVR;
+
+ pm_runtime_put_autosuspend(priv->dev);
+
+ return ret;
+}
+
+static int stm32_vrefbuf_set_voltage_sel(struct regulator_dev *rdev,
+ unsigned sel)
+{
+ struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
+ u32 val;
+ int ret;
+
+ ret = pm_runtime_resume_and_get(priv->dev);
+ if (ret < 0)
+ return ret;
+
+ val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
+ val = (val & ~STM32_VRS) | FIELD_PREP(STM32_VRS, sel);
+ writel_relaxed(val, priv->base + STM32_VREFBUF_CSR);
+
+ pm_runtime_put_autosuspend(priv->dev);
+
+ return 0;
+}
+
+static int stm32_vrefbuf_get_voltage_sel(struct regulator_dev *rdev)
+{
+ struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
+ u32 val;
+ int ret;
+
+ ret = pm_runtime_resume_and_get(priv->dev);
+ if (ret < 0)
+ return ret;
+
+ val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
+ ret = FIELD_GET(STM32_VRS, val);
+
+ pm_runtime_put_autosuspend(priv->dev);
+
+ return ret;
+}
+
+static const struct regulator_ops stm32_vrefbuf_volt_ops = {
+ .enable = stm32_vrefbuf_enable,
+ .disable = stm32_vrefbuf_disable,
+ .is_enabled = stm32_vrefbuf_is_enabled,
+ .get_voltage_sel = stm32_vrefbuf_get_voltage_sel,
+ .set_voltage_sel = stm32_vrefbuf_set_voltage_sel,
+ .list_voltage = regulator_list_voltage_table,
+};
+
+static const struct regulator_desc stm32_vrefbuf_regu = {
+ .name = "vref",
+ .supply_name = "vdda",
+ .volt_table = stm32_vrefbuf_voltages,
+ .n_voltages = ARRAY_SIZE(stm32_vrefbuf_voltages),
+ .ops = &stm32_vrefbuf_volt_ops,
+ .off_on_delay = 1000,
+ .type = REGULATOR_VOLTAGE,
+ .owner = THIS_MODULE,
+};
+
+static int stm32_vrefbuf_probe(struct platform_device *pdev)
+{
+ struct stm32_vrefbuf *priv;
+ struct regulator_config config = { };
+ struct regulator_dev *rdev;
+ int ret;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+ priv->dev = &pdev->dev;
+
+ priv->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(priv->base))
+ return PTR_ERR(priv->base);
+
+ priv->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(priv->clk))
+ return PTR_ERR(priv->clk);
+
+ pm_runtime_get_noresume(&pdev->dev);
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_set_autosuspend_delay(&pdev->dev,
+ STM32_VREFBUF_AUTO_SUSPEND_DELAY_MS);
+ pm_runtime_use_autosuspend(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+
+ ret = clk_prepare_enable(priv->clk);
+ if (ret) {
+ dev_err(&pdev->dev, "clk prepare failed with error %d\n", ret);
+ goto err_pm_stop;
+ }
+
+ config.dev = &pdev->dev;
+ config.driver_data = priv;
+ config.of_node = pdev->dev.of_node;
+ config.init_data = of_get_regulator_init_data(&pdev->dev,
+ pdev->dev.of_node,
+ &stm32_vrefbuf_regu);
+
+ rdev = regulator_register(&pdev->dev, &stm32_vrefbuf_regu, &config);
+ if (IS_ERR(rdev)) {
+ ret = PTR_ERR(rdev);
+ dev_err(&pdev->dev, "register failed with error %d\n", ret);
+ goto err_clk_dis;
+ }
+ platform_set_drvdata(pdev, rdev);
+
+ pm_runtime_put_autosuspend(&pdev->dev);
+
+ return 0;
+
+err_clk_dis:
+ clk_disable_unprepare(priv->clk);
+err_pm_stop:
+ pm_runtime_disable(&pdev->dev);
+ pm_runtime_set_suspended(&pdev->dev);
+ pm_runtime_put_noidle(&pdev->dev);
+
+ return ret;
+}
+
+static void stm32_vrefbuf_remove(struct platform_device *pdev)
+{
+ struct regulator_dev *rdev = platform_get_drvdata(pdev);
+ struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
+
+ pm_runtime_get_sync(&pdev->dev);
+ regulator_unregister(rdev);
+ clk_disable_unprepare(priv->clk);
+ pm_runtime_disable(&pdev->dev);
+ pm_runtime_set_suspended(&pdev->dev);
+ pm_runtime_put_noidle(&pdev->dev);
+};
+
+static int __maybe_unused stm32_vrefbuf_runtime_suspend(struct device *dev)
+{
+ struct regulator_dev *rdev = dev_get_drvdata(dev);
+ struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
+
+ clk_disable_unprepare(priv->clk);
+
+ return 0;
+}
+
+static int __maybe_unused stm32_vrefbuf_runtime_resume(struct device *dev)
+{
+ struct regulator_dev *rdev = dev_get_drvdata(dev);
+ struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
+
+ return clk_prepare_enable(priv->clk);
+}
+
+static const struct dev_pm_ops stm32_vrefbuf_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+ pm_runtime_force_resume)
+ SET_RUNTIME_PM_OPS(stm32_vrefbuf_runtime_suspend,
+ stm32_vrefbuf_runtime_resume,
+ NULL)
+};
+
+static const struct of_device_id __maybe_unused stm32_vrefbuf_of_match[] = {
+ { .compatible = "st,stm32-vrefbuf", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, stm32_vrefbuf_of_match);
+
+static struct platform_driver stm32_vrefbuf_driver = {
+ .probe = stm32_vrefbuf_probe,
+ .remove = stm32_vrefbuf_remove,
+ .driver = {
+ .name = "stm32-vrefbuf",
+ .probe_type = PROBE_PREFER_ASYNCHRONOUS,
+ .of_match_table = of_match_ptr(stm32_vrefbuf_of_match),
+ .pm = &stm32_vrefbuf_pm_ops,
+ },
+};
+module_platform_driver(stm32_vrefbuf_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics STM32 VREFBUF driver");
+MODULE_ALIAS("platform:stm32-vrefbuf");