/* * exynos_adc.c - Support for ADC in EXYNOS SoCs * * 8 ~ 10 channel, 10/12-bit ADC * * Copyright (C) 2013 Naveen Krishna Chatradhi * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * 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, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include enum adc_version { ADC_V1, ADC_V2 }; /* EXYNOS4412/5250 ADC_V1 registers definitions */ #define ADC_V1_CON(x) ((x) + 0x00) #define ADC_V1_DLY(x) ((x) + 0x08) #define ADC_V1_DATX(x) ((x) + 0x0C) #define ADC_V1_INTCLR(x) ((x) + 0x18) #define ADC_V1_MUX(x) ((x) + 0x1c) /* Future ADC_V2 registers definitions */ #define ADC_V2_CON1(x) ((x) + 0x00) #define ADC_V2_CON2(x) ((x) + 0x04) #define ADC_V2_STAT(x) ((x) + 0x08) #define ADC_V2_INT_EN(x) ((x) + 0x10) #define ADC_V2_INT_ST(x) ((x) + 0x14) #define ADC_V2_VER(x) ((x) + 0x20) /* Bit definitions for ADC_V1 */ #define ADC_V1_CON_RES (1u << 16) #define ADC_V1_CON_PRSCEN (1u << 14) #define ADC_V1_CON_PRSCLV(x) (((x) & 0xFF) << 6) #define ADC_V1_CON_STANDBY (1u << 2) /* Bit definitions for ADC_V2 */ #define ADC_V2_CON1_SOFT_RESET (1u << 2) #define ADC_V2_CON2_OSEL (1u << 10) #define ADC_V2_CON2_ESEL (1u << 9) #define ADC_V2_CON2_HIGHF (1u << 8) #define ADC_V2_CON2_C_TIME(x) (((x) & 7) << 4) #define ADC_V2_CON2_ACH_SEL(x) (((x) & 0xF) << 0) #define ADC_V2_CON2_ACH_MASK 0xF #define MAX_ADC_V2_CHANNELS 10 #define MAX_ADC_V1_CHANNELS 8 /* Bit definitions common for ADC_V1 and ADC_V2 */ #define ADC_CON_EN_START (1u << 0) #define ADC_DATX_MASK 0xFFF #define EXYNOS_ADC_TIMEOUT (msecs_to_jiffies(1000)) struct exynos_adc { void __iomem *regs; struct clk *clk; unsigned int irq; struct regulator *vdd; struct completion completion; u32 value; unsigned int version; }; static const struct of_device_id exynos_adc_match[] = { { .compatible = "samsung,exynos-adc-v1", .data = (void *)ADC_V1 }, { .compatible = "samsung,exynos-adc-v2", .data = (void *)ADC_V2 }, {}, }; MODULE_DEVICE_TABLE(of, exynos_adc_match); static inline unsigned int exynos_adc_get_version(struct platform_device *pdev) { const struct of_device_id *match; match = of_match_node(exynos_adc_match, pdev->dev.of_node); return (unsigned int)match->data; } static int exynos_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct exynos_adc *info = iio_priv(indio_dev); unsigned long timeout; u32 con1, con2; if (mask != IIO_CHAN_INFO_RAW) return -EINVAL; mutex_lock(&indio_dev->mlock); /* Select the channel to be used and Trigger conversion */ if (info->version == ADC_V2) { con2 = readl(ADC_V2_CON2(info->regs)); con2 &= ~ADC_V2_CON2_ACH_MASK; con2 |= ADC_V2_CON2_ACH_SEL(chan->address); writel(con2, ADC_V2_CON2(info->regs)); con1 = readl(ADC_V2_CON1(info->regs)); writel(con1 | ADC_CON_EN_START, ADC_V2_CON1(info->regs)); } else { writel(chan->address, ADC_V1_MUX(info->regs)); con1 = readl(ADC_V1_CON(info->regs)); writel(con1 | ADC_CON_EN_START, ADC_V1_CON(info->regs)); } timeout = wait_for_completion_interruptible_timeout (&info->completion, EXYNOS_ADC_TIMEOUT); *val = info->value; mutex_unlock(&indio_dev->mlock); if (timeout == 0) return -ETIMEDOUT; return IIO_VAL_INT; } static irqreturn_t exynos_adc_isr(int irq, void *dev_id) { struct exynos_adc *info = (struct exynos_adc *)dev_id; /* Read value */ info->value = readl(ADC_V1_DATX(info->regs)) & ADC_DATX_MASK; /* clear irq */ if (info->version == ADC_V2) writel(1, ADC_V2_INT_ST(info->regs)); else writel(1, ADC_V1_INTCLR(info->regs)); complete(&info->completion); return IRQ_HANDLED; } static int exynos_adc_reg_access(struct iio_dev *indio_dev, unsigned reg, unsigned writeval, unsigned *readval) { struct exynos_adc *info = iio_priv(indio_dev); if (readval == NULL) return -EINVAL; *readval = readl(info->regs + reg); return 0; } static const struct iio_info exynos_adc_iio_info = { .read_raw = &exynos_read_raw, .debugfs_reg_access = &exynos_adc_reg_access, .driver_module = THIS_MODULE, }; #define ADC_CHANNEL(_index, _id) { \ .type = IIO_VOLTAGE, \ .indexed = 1, \ .channel = _index, \ .address = _index, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .datasheet_name = _id, \ } static const struct iio_chan_spec exynos_adc_iio_channels[] = { ADC_CHANNEL(0, "adc0"), ADC_CHANNEL(1, "adc1"), ADC_CHANNEL(2, "adc2"), ADC_CHANNEL(3, "adc3"), ADC_CHANNEL(4, "adc4"), ADC_CHANNEL(5, "adc5"), ADC_CHANNEL(6, "adc6"), ADC_CHANNEL(7, "adc7"), ADC_CHANNEL(8, "adc8"), ADC_CHANNEL(9, "adc9"), }; static int exynos_adc_remove_devices(struct device *dev, void *c) { struct platform_device *pdev = to_platform_device(dev); platform_device_unregister(pdev); return 0; } static void exynos_adc_hw_init(struct exynos_adc *info) { u32 con1, con2; if (info->version == ADC_V2) { con1 = ADC_V2_CON1_SOFT_RESET; writel(con1, ADC_V2_CON1(info->regs)); con2 = ADC_V2_CON2_OSEL | ADC_V2_CON2_ESEL | ADC_V2_CON2_HIGHF | ADC_V2_CON2_C_TIME(0); writel(con2, ADC_V2_CON2(info->regs)); /* Enable interrupts */ writel(1, ADC_V2_INT_EN(info->regs)); } else { /* set default prescaler values and Enable prescaler */ con1 = ADC_V1_CON_PRSCLV(49) | ADC_V1_CON_PRSCEN; /* Enable 12-bit ADC resolution */ con1 |= ADC_V1_CON_RES; writel(con1, ADC_V1_CON(info->regs)); } } static int exynos_adc_probe(struct platform_device *pdev) { struct exynos_adc *info = NULL; struct device_node *np = pdev->dev.of_node; struct iio_dev *indio_dev = NULL; struct resource *mem; int ret = -ENODEV; int irq; if (!np) return ret; indio_dev = iio_device_alloc(sizeof(struct exynos_adc)); if (!indio_dev) { dev_err(&pdev->dev, "failed allocating iio device\n"); return -ENOMEM; } info = iio_priv(indio_dev); mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); info->regs = devm_request_and_ioremap(&pdev->dev, mem); if (!info->regs) { ret = -ENOMEM; goto err_iio; } irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(&pdev->dev, "no irq resource?\n"); ret = irq; goto err_iio; } info->irq = irq; init_completion(&info->completion); ret = request_irq(info->irq, exynos_adc_isr, 0, dev_name(&pdev->dev), info); if (ret < 0) { dev_err(&pdev->dev, "failed requesting irq, irq = %d\n", info->irq); goto err_iio; } info->clk = devm_clk_get(&pdev->dev, "adc"); if (IS_ERR(info->clk)) { dev_err(&pdev->dev, "failed getting clock, err = %ld\n", PTR_ERR(info->clk)); ret = PTR_ERR(info->clk); goto err_irq; } info->vdd = devm_regulator_get(&pdev->dev, "vdd"); if (IS_ERR(info->vdd)) { dev_err(&pdev->dev, "failed getting regulator, err = %ld\n", PTR_ERR(info->vdd)); ret = PTR_ERR(info->vdd); goto err_irq; } info->version = exynos_adc_get_version(pdev); platform_set_drvdata(pdev, indio_dev); indio_dev->name = dev_name(&pdev->dev); indio_dev->dev.parent = &pdev->dev; indio_dev->dev.of_node = pdev->dev.of_node; indio_dev->info = &exynos_adc_iio_info; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = exynos_adc_iio_channels; if (info->version == ADC_V1) indio_dev->num_channels = MAX_ADC_V1_CHANNELS; else indio_dev->num_channels = MAX_ADC_V2_CHANNELS; ret = iio_device_register(indio_dev); if (ret) goto err_irq; ret = regulator_enable(info->vdd); if (ret) goto err_iio_dev; clk_prepare_enable(info->clk); exynos_adc_hw_init(info); ret = of_platform_populate(np, exynos_adc_match, NULL, &pdev->dev); if (ret < 0) { dev_err(&pdev->dev, "failed adding child nodes\n"); goto err_of_populate; } return 0; err_of_populate: device_for_each_child(&pdev->dev, NULL, exynos_adc_remove_devices); regulator_disable(info->vdd); clk_disable_unprepare(info->clk); err_iio_dev: iio_device_unregister(indio_dev); err_irq: free_irq(info->irq, info); err_iio: iio_device_free(indio_dev); return ret; } static int exynos_adc_remove(struct platform_device *pdev) { struct iio_dev *indio_dev = platform_get_drvdata(pdev); struct exynos_adc *info = iio_priv(indio_dev); device_for_each_child(&pdev->dev, NULL, exynos_adc_remove_devices); regulator_disable(info->vdd); clk_disable_unprepare(info->clk); iio_device_unregister(indio_dev); free_irq(info->irq, info); iio_device_free(indio_dev); return 0; } #ifdef CONFIG_PM_SLEEP static int exynos_adc_suspend(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct exynos_adc *info = platform_get_drvdata(pdev); u32 con; if (info->version == ADC_V2) { con = readl(ADC_V2_CON1(info->regs)); con &= ~ADC_CON_EN_START; writel(con, ADC_V2_CON1(info->regs)); } else { con = readl(ADC_V1_CON(info->regs)); con |= ADC_V1_CON_STANDBY; writel(con, ADC_V1_CON(info->regs)); } clk_disable_unprepare(info->clk); regulator_disable(info->vdd); return 0; } static int exynos_adc_resume(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct exynos_adc *info = platform_get_drvdata(pdev); int ret; ret = regulator_enable(info->vdd); if (ret) return ret; clk_prepare_enable(info->clk); exynos_adc_hw_init(info); return 0; } #endif static SIMPLE_DEV_PM_OPS(exynos_adc_pm_ops, exynos_adc_suspend, exynos_adc_resume); static struct platform_driver exynos_adc_driver = { .probe = exynos_adc_probe, .remove = exynos_adc_remove, .driver = { .name = "exynos-adc", .owner = THIS_MODULE, .of_match_table = of_match_ptr(exynos_adc_match), .pm = &exynos_adc_pm_ops, }, }; module_platform_driver(exynos_adc_driver); MODULE_AUTHOR("Naveen Krishna Chatradhi "); MODULE_DESCRIPTION("Samsung EXYNOS5 ADC driver"); MODULE_LICENSE("GPL v2");