diff options
Diffstat (limited to 'drivers/iio/dac/stm32-dac-core.c')
-rw-r--r-- | drivers/iio/dac/stm32-dac-core.c | 264 |
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 0000000000..83bf184e3a --- /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"); |