/* * This file is part of STM32 ADC driver * * Copyright (C) 2016, STMicroelectronics - All Rights Reserved * Author: Fabrice Gasnier . * * Inspired from: fsl-imx25-tsadc * * 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 . */ #include #include #include #include #include #include #include #include #include #include "stm32-adc-core.h" /* STM32F4 - common registers for all ADC instances: 1, 2 & 3 */ #define STM32F4_ADC_CSR (STM32_ADCX_COMN_OFFSET + 0x00) #define STM32F4_ADC_CCR (STM32_ADCX_COMN_OFFSET + 0x04) /* STM32F4_ADC_CSR - bit fields */ #define STM32F4_EOC3 BIT(17) #define STM32F4_EOC2 BIT(9) #define STM32F4_EOC1 BIT(1) /* STM32F4_ADC_CCR - bit fields */ #define STM32F4_ADC_ADCPRE_SHIFT 16 #define STM32F4_ADC_ADCPRE_MASK GENMASK(17, 16) /* STM32 F4 maximum analog clock rate (from datasheet) */ #define STM32F4_ADC_MAX_CLK_RATE 36000000 /** * struct stm32_adc_priv - stm32 ADC core private data * @irq: irq for ADC block * @domain: irq domain reference * @aclk: clock reference for the analog circuitry * @vref: regulator reference * @common: common data for all ADC instances */ struct stm32_adc_priv { int irq; struct irq_domain *domain; struct clk *aclk; struct regulator *vref; struct stm32_adc_common common; }; static struct stm32_adc_priv *to_stm32_adc_priv(struct stm32_adc_common *com) { return container_of(com, struct stm32_adc_priv, common); } /* STM32F4 ADC internal common clock prescaler division ratios */ static int stm32f4_pclk_div[] = {2, 4, 6, 8}; /** * stm32f4_adc_clk_sel() - Select stm32f4 ADC common clock prescaler * @priv: stm32 ADC core private data * Select clock prescaler used for analog conversions, before using ADC. */ static int stm32f4_adc_clk_sel(struct platform_device *pdev, struct stm32_adc_priv *priv) { unsigned long rate; u32 val; int i; rate = clk_get_rate(priv->aclk); for (i = 0; i < ARRAY_SIZE(stm32f4_pclk_div); i++) { if ((rate / stm32f4_pclk_div[i]) <= STM32F4_ADC_MAX_CLK_RATE) break; } if (i >= ARRAY_SIZE(stm32f4_pclk_div)) return -EINVAL; val = readl_relaxed(priv->common.base + STM32F4_ADC_CCR); val &= ~STM32F4_ADC_ADCPRE_MASK; val |= i << STM32F4_ADC_ADCPRE_SHIFT; writel_relaxed(val, priv->common.base + STM32F4_ADC_CCR); dev_dbg(&pdev->dev, "Using analog clock source at %ld kHz\n", rate / (stm32f4_pclk_div[i] * 1000)); return 0; } /* ADC common interrupt for all instances */ static void stm32_adc_irq_handler(struct irq_desc *desc) { struct stm32_adc_priv *priv = irq_desc_get_handler_data(desc); struct irq_chip *chip = irq_desc_get_chip(desc); u32 status; chained_irq_enter(chip, desc); status = readl_relaxed(priv->common.base + STM32F4_ADC_CSR); if (status & STM32F4_EOC1) generic_handle_irq(irq_find_mapping(priv->domain, 0)); if (status & STM32F4_EOC2) generic_handle_irq(irq_find_mapping(priv->domain, 1)); if (status & STM32F4_EOC3) generic_handle_irq(irq_find_mapping(priv->domain, 2)); chained_irq_exit(chip, desc); }; static int stm32_adc_domain_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hwirq) { irq_set_chip_data(irq, d->host_data); irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_level_irq); return 0; } static void stm32_adc_domain_unmap(struct irq_domain *d, unsigned int irq) { irq_set_chip_and_handler(irq, NULL, NULL); irq_set_chip_data(irq, NULL); } static const struct irq_domain_ops stm32_adc_domain_ops = { .map = stm32_adc_domain_map, .unmap = stm32_adc_domain_unmap, .xlate = irq_domain_xlate_onecell, }; static int stm32_adc_irq_probe(struct platform_device *pdev, struct stm32_adc_priv *priv) { struct device_node *np = pdev->dev.of_node; priv->irq = platform_get_irq(pdev, 0); if (priv->irq < 0) { dev_err(&pdev->dev, "failed to get irq\n"); return priv->irq; } priv->domain = irq_domain_add_simple(np, STM32_ADC_MAX_ADCS, 0, &stm32_adc_domain_ops, priv); if (!priv->domain) { dev_err(&pdev->dev, "Failed to add irq domain\n"); return -ENOMEM; } irq_set_chained_handler(priv->irq, stm32_adc_irq_handler); irq_set_handler_data(priv->irq, priv); return 0; } static void stm32_adc_irq_remove(struct platform_device *pdev, struct stm32_adc_priv *priv) { int hwirq; for (hwirq = 0; hwirq < STM32_ADC_MAX_ADCS; hwirq++) irq_dispose_mapping(irq_find_mapping(priv->domain, hwirq)); irq_domain_remove(priv->domain); irq_set_chained_handler(priv->irq, NULL); } static int stm32_adc_probe(struct platform_device *pdev) { struct stm32_adc_priv *priv; struct device_node *np = pdev->dev.of_node; struct resource *res; int ret; if (!pdev->dev.of_node) return -ENODEV; priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); priv->common.base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(priv->common.base)) return PTR_ERR(priv->common.base); priv->common.phys_base = res->start; priv->vref = devm_regulator_get(&pdev->dev, "vref"); if (IS_ERR(priv->vref)) { ret = PTR_ERR(priv->vref); dev_err(&pdev->dev, "vref get failed, %d\n", ret); return ret; } ret = regulator_enable(priv->vref); if (ret < 0) { dev_err(&pdev->dev, "vref enable failed\n"); return ret; } ret = regulator_get_voltage(priv->vref); if (ret < 0) { dev_err(&pdev->dev, "vref get voltage failed, %d\n", ret); goto err_regulator_disable; } priv->common.vref_mv = ret / 1000; dev_dbg(&pdev->dev, "vref+=%dmV\n", priv->common.vref_mv); priv->aclk = devm_clk_get(&pdev->dev, "adc"); if (IS_ERR(priv->aclk)) { ret = PTR_ERR(priv->aclk); dev_err(&pdev->dev, "Can't get 'adc' clock\n"); goto err_regulator_disable; } ret = clk_prepare_enable(priv->aclk); if (ret < 0) { dev_err(&pdev->dev, "adc clk enable failed\n"); goto err_regulator_disable; } ret = stm32f4_adc_clk_sel(pdev, priv); if (ret < 0) { dev_err(&pdev->dev, "adc clk selection failed\n"); goto err_clk_disable; } ret = stm32_adc_irq_probe(pdev, priv); if (ret < 0) goto err_clk_disable; platform_set_drvdata(pdev, &priv->common); ret = of_platform_populate(np, NULL, NULL, &pdev->dev); if (ret < 0) { dev_err(&pdev->dev, "failed to populate DT children\n"); goto err_irq_remove; } return 0; err_irq_remove: stm32_adc_irq_remove(pdev, priv); err_clk_disable: clk_disable_unprepare(priv->aclk); err_regulator_disable: regulator_disable(priv->vref); return ret; } static int stm32_adc_remove(struct platform_device *pdev) { struct stm32_adc_common *common = platform_get_drvdata(pdev); struct stm32_adc_priv *priv = to_stm32_adc_priv(common); of_platform_depopulate(&pdev->dev); stm32_adc_irq_remove(pdev, priv); clk_disable_unprepare(priv->aclk); regulator_disable(priv->vref); return 0; } static const struct of_device_id stm32_adc_of_match[] = { { .compatible = "st,stm32f4-adc-core" }, {}, }; MODULE_DEVICE_TABLE(of, stm32_adc_of_match); static struct platform_driver stm32_adc_driver = { .probe = stm32_adc_probe, .remove = stm32_adc_remove, .driver = { .name = "stm32-adc-core", .of_match_table = stm32_adc_of_match, }, }; module_platform_driver(stm32_adc_driver); MODULE_AUTHOR("Fabrice Gasnier "); MODULE_DESCRIPTION("STMicroelectronics STM32 ADC core driver"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:stm32-adc-core");