Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 264 insertions, 0 deletions

diff --git a/drivers/iio/dac/stm32-dac-core.c b/drivers/iio/dac/stm32-dac-core.c
new file mode 100644
index 000000000..83bf184e3
--- /dev/null
+++ b/drivers/iio/dac/stm32-dac-core.c
@@ -0,0 +1,264 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This file is part of STM32 DAC driver
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+
+#include "stm32-dac-core.h"
+
+/**
+ * struct stm32_dac_priv - stm32 DAC core private data
+ * @pclk:		peripheral clock common for all DACs
+ * @vref:		regulator reference
+ * @common:		Common data for all DAC instances
+ */
+struct stm32_dac_priv {
+	struct clk *pclk;
+	struct regulator *vref;
+	struct stm32_dac_common common;
+};
+
+/**
+ * struct stm32_dac_cfg - DAC configuration
+ * @has_hfsel: DAC has high frequency control
+ */
+struct stm32_dac_cfg {
+	bool has_hfsel;
+};
+
+static struct stm32_dac_priv *to_stm32_dac_priv(struct stm32_dac_common *com)
+{
+	return container_of(com, struct stm32_dac_priv, common);
+}
+
+static const struct regmap_config stm32_dac_regmap_cfg = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = sizeof(u32),
+	.max_register = 0x3fc,
+};
+
+static int stm32_dac_core_hw_start(struct device *dev)
+{
+	struct stm32_dac_common *common = dev_get_drvdata(dev);
+	struct stm32_dac_priv *priv = to_stm32_dac_priv(common);
+	int ret;
+
+	ret = regulator_enable(priv->vref);
+	if (ret < 0) {
+		dev_err(dev, "vref enable failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(priv->pclk);
+	if (ret < 0) {
+		dev_err(dev, "pclk enable failed: %d\n", ret);
+		goto err_regulator_disable;
+	}
+
+	return 0;
+
+err_regulator_disable:
+	regulator_disable(priv->vref);
+
+	return ret;
+}
+
+static void stm32_dac_core_hw_stop(struct device *dev)
+{
+	struct stm32_dac_common *common = dev_get_drvdata(dev);
+	struct stm32_dac_priv *priv = to_stm32_dac_priv(common);
+
+	clk_disable_unprepare(priv->pclk);
+	regulator_disable(priv->vref);
+}
+
+static int stm32_dac_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	const struct stm32_dac_cfg *cfg;
+	struct stm32_dac_priv *priv;
+	struct regmap *regmap;
+	void __iomem *mmio;
+	struct reset_control *rst;
+	int ret;
+
+	if (!dev->of_node)
+		return -ENODEV;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, &priv->common);
+
+	cfg = (const struct stm32_dac_cfg *)
+		of_match_device(dev->driver->of_match_table, dev)->data;
+
+	mmio = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mmio))
+		return PTR_ERR(mmio);
+
+	regmap = devm_regmap_init_mmio_clk(dev, "pclk", mmio,
+					   &stm32_dac_regmap_cfg);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+	priv->common.regmap = regmap;
+
+	priv->pclk = devm_clk_get(dev, "pclk");
+	if (IS_ERR(priv->pclk))
+		return dev_err_probe(dev, PTR_ERR(priv->pclk), "pclk get failed\n");
+
+	priv->vref = devm_regulator_get(dev, "vref");
+	if (IS_ERR(priv->vref))
+		return dev_err_probe(dev, PTR_ERR(priv->vref), "vref get failed\n");
+
+	pm_runtime_get_noresume(dev);
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+
+	ret = stm32_dac_core_hw_start(dev);
+	if (ret)
+		goto err_pm_stop;
+
+	ret = regulator_get_voltage(priv->vref);
+	if (ret < 0) {
+		dev_err(dev, "vref get voltage failed, %d\n", ret);
+		goto err_hw_stop;
+	}
+	priv->common.vref_mv = ret / 1000;
+	dev_dbg(dev, "vref+=%dmV\n", priv->common.vref_mv);
+
+	rst = devm_reset_control_get_optional_exclusive(dev, NULL);
+	if (rst) {
+		if (IS_ERR(rst)) {
+			ret = dev_err_probe(dev, PTR_ERR(rst), "reset get failed\n");
+			goto err_hw_stop;
+		}
+
+		reset_control_assert(rst);
+		udelay(2);
+		reset_control_deassert(rst);
+	}
+
+	if (cfg && cfg->has_hfsel) {
+		/* When clock speed is higher than 80MHz, set HFSEL */
+		priv->common.hfsel = (clk_get_rate(priv->pclk) > 80000000UL);
+		ret = regmap_update_bits(regmap, STM32_DAC_CR,
+					 STM32H7_DAC_CR_HFSEL,
+					 priv->common.hfsel ?
+					 STM32H7_DAC_CR_HFSEL : 0);
+		if (ret)
+			goto err_hw_stop;
+	}
+
+
+	ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, dev);
+	if (ret < 0) {
+		dev_err(dev, "failed to populate DT children\n");
+		goto err_hw_stop;
+	}
+
+	pm_runtime_put(dev);
+
+	return 0;
+
+err_hw_stop:
+	stm32_dac_core_hw_stop(dev);
+err_pm_stop:
+	pm_runtime_disable(dev);
+	pm_runtime_set_suspended(dev);
+	pm_runtime_put_noidle(dev);
+
+	return ret;
+}
+
+static int stm32_dac_remove(struct platform_device *pdev)
+{
+	pm_runtime_get_sync(&pdev->dev);
+	of_platform_depopulate(&pdev->dev);
+	stm32_dac_core_hw_stop(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	pm_runtime_put_noidle(&pdev->dev);
+
+	return 0;
+}
+
+static int stm32_dac_core_resume(struct device *dev)
+{
+	struct stm32_dac_common *common = dev_get_drvdata(dev);
+	struct stm32_dac_priv *priv = to_stm32_dac_priv(common);
+	int ret;
+
+	if (priv->common.hfsel) {
+		/* restore hfsel (maybe lost under low power state) */
+		ret = regmap_update_bits(priv->common.regmap, STM32_DAC_CR,
+					 STM32H7_DAC_CR_HFSEL,
+					 STM32H7_DAC_CR_HFSEL);
+		if (ret)
+			return ret;
+	}
+
+	return pm_runtime_force_resume(dev);
+}
+
+static int stm32_dac_core_runtime_suspend(struct device *dev)
+{
+	stm32_dac_core_hw_stop(dev);
+
+	return 0;
+}
+
+static int stm32_dac_core_runtime_resume(struct device *dev)
+{
+	return stm32_dac_core_hw_start(dev);
+}
+
+static const struct dev_pm_ops stm32_dac_core_pm_ops = {
+	SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, stm32_dac_core_resume)
+	RUNTIME_PM_OPS(stm32_dac_core_runtime_suspend,
+		       stm32_dac_core_runtime_resume,
+		       NULL)
+};
+
+static const struct stm32_dac_cfg stm32h7_dac_cfg = {
+	.has_hfsel = true,
+};
+
+static const struct of_device_id stm32_dac_of_match[] = {
+	{
+		.compatible = "st,stm32f4-dac-core",
+	}, {
+		.compatible = "st,stm32h7-dac-core",
+		.data = (void *)&stm32h7_dac_cfg,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, stm32_dac_of_match);
+
+static struct platform_driver stm32_dac_driver = {
+	.probe = stm32_dac_probe,
+	.remove = stm32_dac_remove,
+	.driver = {
+		.name = "stm32-dac-core",
+		.of_match_table = stm32_dac_of_match,
+		.pm = pm_ptr(&stm32_dac_core_pm_ops),
+	},
+};
+module_platform_driver(stm32_dac_driver);
+
+MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics STM32 DAC core driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:stm32-dac-core");