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