| /* |
| * Rockchip Successive Approximation Register (SAR) A/D Converter |
| * Copyright (C) 2014 ROCKCHIP, Inc. |
| * |
| * 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. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/platform_device.h> |
| #include <linux/interrupt.h> |
| #include <linux/io.h> |
| #include <linux/of.h> |
| #include <linux/clk.h> |
| #include <linux/completion.h> |
| #include <linux/regulator/consumer.h> |
| #include <linux/iio/iio.h> |
| |
| #define SARADC_DATA 0x00 |
| #define SARADC_DATA_MASK 0x3ff |
| |
| #define SARADC_STAS 0x04 |
| #define SARADC_STAS_BUSY BIT(0) |
| |
| #define SARADC_CTRL 0x08 |
| #define SARADC_CTRL_IRQ_STATUS BIT(6) |
| #define SARADC_CTRL_IRQ_ENABLE BIT(5) |
| #define SARADC_CTRL_POWER_CTRL BIT(3) |
| #define SARADC_CTRL_CHN_MASK 0x7 |
| |
| #define SARADC_DLY_PU_SOC 0x0c |
| #define SARADC_DLY_PU_SOC_MASK 0x3f |
| |
| #define SARADC_BITS 10 |
| #define SARADC_TIMEOUT msecs_to_jiffies(100) |
| |
| struct rockchip_saradc { |
| void __iomem *regs; |
| struct clk *pclk; |
| struct clk *clk; |
| struct completion completion; |
| struct regulator *vref; |
| u16 last_val; |
| }; |
| |
| static int rockchip_saradc_read_raw(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, |
| int *val, int *val2, long mask) |
| { |
| struct rockchip_saradc *info = iio_priv(indio_dev); |
| int ret; |
| |
| switch (mask) { |
| case IIO_CHAN_INFO_RAW: |
| mutex_lock(&indio_dev->mlock); |
| |
| reinit_completion(&info->completion); |
| |
| /* 8 clock periods as delay between power up and start cmd */ |
| writel_relaxed(8, info->regs + SARADC_DLY_PU_SOC); |
| |
| /* Select the channel to be used and trigger conversion */ |
| writel(SARADC_CTRL_POWER_CTRL |
| | (chan->channel & SARADC_CTRL_CHN_MASK) |
| | SARADC_CTRL_IRQ_ENABLE, |
| info->regs + SARADC_CTRL); |
| |
| if (!wait_for_completion_timeout(&info->completion, |
| SARADC_TIMEOUT)) { |
| writel_relaxed(0, info->regs + SARADC_CTRL); |
| mutex_unlock(&indio_dev->mlock); |
| return -ETIMEDOUT; |
| } |
| |
| *val = info->last_val; |
| mutex_unlock(&indio_dev->mlock); |
| return IIO_VAL_INT; |
| case IIO_CHAN_INFO_SCALE: |
| ret = regulator_get_voltage(info->vref); |
| if (ret < 0) { |
| dev_err(&indio_dev->dev, "failed to get voltage\n"); |
| return ret; |
| } |
| |
| *val = ret / 1000; |
| *val2 = SARADC_BITS; |
| return IIO_VAL_FRACTIONAL_LOG2; |
| default: |
| return -EINVAL; |
| } |
| } |
| |
| static irqreturn_t rockchip_saradc_isr(int irq, void *dev_id) |
| { |
| struct rockchip_saradc *info = (struct rockchip_saradc *)dev_id; |
| |
| /* Read value */ |
| info->last_val = readl_relaxed(info->regs + SARADC_DATA); |
| info->last_val &= SARADC_DATA_MASK; |
| |
| /* Clear irq & power down adc */ |
| writel_relaxed(0, info->regs + SARADC_CTRL); |
| |
| complete(&info->completion); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static const struct iio_info rockchip_saradc_iio_info = { |
| .read_raw = rockchip_saradc_read_raw, |
| .driver_module = THIS_MODULE, |
| }; |
| |
| #define ADC_CHANNEL(_index, _id) { \ |
| .type = IIO_VOLTAGE, \ |
| .indexed = 1, \ |
| .channel = _index, \ |
| .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
| .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ |
| .datasheet_name = _id, \ |
| } |
| |
| static const struct iio_chan_spec rockchip_saradc_iio_channels[] = { |
| ADC_CHANNEL(0, "adc0"), |
| ADC_CHANNEL(1, "adc1"), |
| ADC_CHANNEL(2, "adc2"), |
| }; |
| |
| static int rockchip_saradc_probe(struct platform_device *pdev) |
| { |
| struct rockchip_saradc *info = NULL; |
| struct device_node *np = pdev->dev.of_node; |
| struct iio_dev *indio_dev = NULL; |
| struct resource *mem; |
| int ret; |
| int irq; |
| u32 rate; |
| |
| if (!np) |
| return -ENODEV; |
| |
| indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info)); |
| 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_ioremap_resource(&pdev->dev, mem); |
| if (IS_ERR(info->regs)) |
| return PTR_ERR(info->regs); |
| |
| init_completion(&info->completion); |
| |
| irq = platform_get_irq(pdev, 0); |
| if (irq < 0) { |
| dev_err(&pdev->dev, "no irq resource?\n"); |
| return irq; |
| } |
| |
| ret = devm_request_irq(&pdev->dev, irq, rockchip_saradc_isr, |
| 0, dev_name(&pdev->dev), info); |
| if (ret < 0) { |
| dev_err(&pdev->dev, "failed requesting irq %d\n", irq); |
| return ret; |
| } |
| |
| info->pclk = devm_clk_get(&pdev->dev, "apb_pclk"); |
| if (IS_ERR(info->pclk)) { |
| dev_err(&pdev->dev, "failed to get pclk\n"); |
| return PTR_ERR(info->pclk); |
| } |
| |
| info->clk = devm_clk_get(&pdev->dev, "saradc"); |
| if (IS_ERR(info->clk)) { |
| dev_err(&pdev->dev, "failed to get adc clock\n"); |
| return PTR_ERR(info->clk); |
| } |
| |
| info->vref = devm_regulator_get(&pdev->dev, "vref"); |
| if (IS_ERR(info->vref)) { |
| dev_err(&pdev->dev, "failed to get regulator, %ld\n", |
| PTR_ERR(info->vref)); |
| return PTR_ERR(info->vref); |
| } |
| |
| /* |
| * Use a default of 1MHz for the converter clock. |
| * This may become user-configurable in the future. |
| */ |
| ret = clk_set_rate(info->clk, 1000000); |
| if (ret < 0) { |
| dev_err(&pdev->dev, "failed to set adc clk rate, %d\n", ret); |
| return ret; |
| } |
| |
| ret = regulator_enable(info->vref); |
| if (ret < 0) { |
| dev_err(&pdev->dev, "failed to enable vref regulator\n"); |
| return ret; |
| } |
| |
| ret = clk_prepare_enable(info->pclk); |
| if (ret < 0) { |
| dev_err(&pdev->dev, "failed to enable pclk\n"); |
| goto err_reg_voltage; |
| } |
| |
| ret = clk_prepare_enable(info->clk); |
| if (ret < 0) { |
| dev_err(&pdev->dev, "failed to enable converter clock\n"); |
| goto err_pclk; |
| } |
| |
| 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 = &rockchip_saradc_iio_info; |
| indio_dev->modes = INDIO_DIRECT_MODE; |
| |
| indio_dev->channels = rockchip_saradc_iio_channels; |
| indio_dev->num_channels = ARRAY_SIZE(rockchip_saradc_iio_channels); |
| |
| ret = iio_device_register(indio_dev); |
| if (ret) |
| goto err_clk; |
| |
| return 0; |
| |
| err_clk: |
| clk_disable_unprepare(info->clk); |
| err_pclk: |
| clk_disable_unprepare(info->pclk); |
| err_reg_voltage: |
| regulator_disable(info->vref); |
| return ret; |
| } |
| |
| static int rockchip_saradc_remove(struct platform_device *pdev) |
| { |
| struct iio_dev *indio_dev = platform_get_drvdata(pdev); |
| struct rockchip_saradc *info = iio_priv(indio_dev); |
| |
| iio_device_unregister(indio_dev); |
| clk_disable_unprepare(info->clk); |
| clk_disable_unprepare(info->pclk); |
| regulator_disable(info->vref); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_PM_SLEEP |
| static int rockchip_saradc_suspend(struct device *dev) |
| { |
| struct iio_dev *indio_dev = dev_get_drvdata(dev); |
| struct rockchip_saradc *info = iio_priv(indio_dev); |
| |
| clk_disable_unprepare(info->clk); |
| clk_disable_unprepare(info->pclk); |
| regulator_disable(info->vref); |
| |
| return 0; |
| } |
| |
| static int rockchip_saradc_resume(struct device *dev) |
| { |
| struct iio_dev *indio_dev = dev_get_drvdata(dev); |
| struct rockchip_saradc *info = iio_priv(indio_dev); |
| int ret; |
| |
| ret = regulator_enable(info->vref); |
| if (ret) |
| return ret; |
| |
| ret = clk_prepare_enable(info->pclk); |
| if (ret) |
| return ret; |
| |
| ret = clk_prepare_enable(info->clk); |
| if (ret) |
| return ret; |
| |
| return ret; |
| } |
| #endif |
| |
| static SIMPLE_DEV_PM_OPS(rockchip_saradc_pm_ops, |
| rockchip_saradc_suspend, rockchip_saradc_resume); |
| |
| static const struct of_device_id rockchip_saradc_match[] = { |
| { .compatible = "rockchip,saradc" }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(of, rockchip_saradc_match); |
| |
| static struct platform_driver rockchip_saradc_driver = { |
| .probe = rockchip_saradc_probe, |
| .remove = rockchip_saradc_remove, |
| .driver = { |
| .name = "rockchip-saradc", |
| .owner = THIS_MODULE, |
| .of_match_table = rockchip_saradc_match, |
| .pm = &rockchip_saradc_pm_ops, |
| }, |
| }; |
| |
| module_platform_driver(rockchip_saradc_driver); |