diff options
Diffstat (limited to 'drivers/iio/dac/stm32-dac-core.c')
| -rw-r--r-- | drivers/iio/dac/stm32-dac-core.c | 180 |
1 files changed, 180 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 000000000000..75e48788c7ea --- /dev/null +++ b/drivers/iio/dac/stm32-dac-core.c @@ -0,0 +1,180 @@ +/* + * This file is part of STM32 DAC driver + * + * Copyright (C) 2017, STMicroelectronics - All Rights Reserved + * Author: Fabrice Gasnier <fabrice.gasnier@st.com>. + * + * License type: GPLv2 + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. + * See the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/of_platform.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 + * @rst: peripheral reset control + * @vref: regulator reference + * @common: Common data for all DAC instances + */ +struct stm32_dac_priv { + struct clk *pclk; + struct reset_control *rst; + struct regulator *vref; + struct stm32_dac_common common; +}; + +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_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct stm32_dac_priv *priv; + struct regmap *regmap; + struct resource *res; + void __iomem *mmio; + int ret; + + if (!dev->of_node) + return -ENODEV; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + mmio = devm_ioremap_resource(dev, res); + if (IS_ERR(mmio)) + return PTR_ERR(mmio); + + regmap = devm_regmap_init_mmio(dev, mmio, &stm32_dac_regmap_cfg); + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + priv->common.regmap = regmap; + + priv->vref = devm_regulator_get(dev, "vref"); + if (IS_ERR(priv->vref)) { + ret = PTR_ERR(priv->vref); + dev_err(dev, "vref get failed, %d\n", ret); + return ret; + } + + ret = regulator_enable(priv->vref); + if (ret < 0) { + dev_err(dev, "vref enable failed\n"); + return ret; + } + + ret = regulator_get_voltage(priv->vref); + if (ret < 0) { + dev_err(dev, "vref get voltage failed, %d\n", ret); + goto err_vref; + } + priv->common.vref_mv = ret / 1000; + dev_dbg(dev, "vref+=%dmV\n", priv->common.vref_mv); + + priv->pclk = devm_clk_get(dev, "pclk"); + if (IS_ERR(priv->pclk)) { + ret = PTR_ERR(priv->pclk); + dev_err(dev, "pclk get failed\n"); + goto err_vref; + } + + ret = clk_prepare_enable(priv->pclk); + if (ret < 0) { + dev_err(dev, "pclk enable failed\n"); + goto err_vref; + } + + priv->rst = devm_reset_control_get(dev, NULL); + if (!IS_ERR(priv->rst)) { + reset_control_assert(priv->rst); + udelay(2); + reset_control_deassert(priv->rst); + } + + /* 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_pclk; + + platform_set_drvdata(pdev, &priv->common); + + 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_pclk; + } + + return 0; + +err_pclk: + clk_disable_unprepare(priv->pclk); +err_vref: + regulator_disable(priv->vref); + + return ret; +} + +static int stm32_dac_remove(struct platform_device *pdev) +{ + struct stm32_dac_common *common = platform_get_drvdata(pdev); + struct stm32_dac_priv *priv = to_stm32_dac_priv(common); + + of_platform_depopulate(&pdev->dev); + clk_disable_unprepare(priv->pclk); + regulator_disable(priv->vref); + + return 0; +} + +static const struct of_device_id stm32_dac_of_match[] = { + { .compatible = "st,stm32h7-dac-core", }, + {}, +}; +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, + }, +}; +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"); |