/* * Copyright (c) 2016 MediaTek Inc. * Author: Zhiyong Tao * * 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. */ #include #include #include #include #include #include #include #include #include #include #include /* Register definitions */ #define MT6577_AUXADC_CON0 0x00 #define MT6577_AUXADC_CON1 0x04 #define MT6577_AUXADC_CON2 0x10 #define MT6577_AUXADC_STA BIT(0) #define MT6577_AUXADC_DAT0 0x14 #define MT6577_AUXADC_RDY0 BIT(12) #define MT6577_AUXADC_MISC 0x94 #define MT6577_AUXADC_PDN_EN BIT(14) #define MT6577_AUXADC_DAT_MASK 0xfff #define MT6577_AUXADC_SLEEP_US 1000 #define MT6577_AUXADC_TIMEOUT_US 10000 #define MT6577_AUXADC_POWER_READY_MS 1 #define MT6577_AUXADC_SAMPLE_READY_US 25 struct mt6577_auxadc_device { void __iomem *reg_base; struct clk *adc_clk; struct mutex lock; }; #define MT6577_AUXADC_CHANNEL(idx) { \ .type = IIO_VOLTAGE, \ .indexed = 1, \ .channel = (idx), \ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \ } static const struct iio_chan_spec mt6577_auxadc_iio_channels[] = { MT6577_AUXADC_CHANNEL(0), MT6577_AUXADC_CHANNEL(1), MT6577_AUXADC_CHANNEL(2), MT6577_AUXADC_CHANNEL(3), MT6577_AUXADC_CHANNEL(4), MT6577_AUXADC_CHANNEL(5), MT6577_AUXADC_CHANNEL(6), MT6577_AUXADC_CHANNEL(7), MT6577_AUXADC_CHANNEL(8), MT6577_AUXADC_CHANNEL(9), MT6577_AUXADC_CHANNEL(10), MT6577_AUXADC_CHANNEL(11), MT6577_AUXADC_CHANNEL(12), MT6577_AUXADC_CHANNEL(13), MT6577_AUXADC_CHANNEL(14), MT6577_AUXADC_CHANNEL(15), }; static inline void mt6577_auxadc_mod_reg(void __iomem *reg, u32 or_mask, u32 and_mask) { u32 val; val = readl(reg); val |= or_mask; val &= ~and_mask; writel(val, reg); } static int mt6577_auxadc_read(struct iio_dev *indio_dev, struct iio_chan_spec const *chan) { u32 val; void __iomem *reg_channel; int ret; struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev); reg_channel = adc_dev->reg_base + MT6577_AUXADC_DAT0 + chan->channel * 0x04; mutex_lock(&adc_dev->lock); mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_CON1, 0, 1 << chan->channel); /* read channel and make sure old ready bit == 0 */ ret = readl_poll_timeout(reg_channel, val, ((val & MT6577_AUXADC_RDY0) == 0), MT6577_AUXADC_SLEEP_US, MT6577_AUXADC_TIMEOUT_US); if (ret < 0) { dev_err(indio_dev->dev.parent, "wait for channel[%d] ready bit clear time out\n", chan->channel); goto err_timeout; } /* set bit to trigger sample */ mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_CON1, 1 << chan->channel, 0); /* we must delay here for hardware sample channel data */ udelay(MT6577_AUXADC_SAMPLE_READY_US); /* check MTK_AUXADC_CON2 if auxadc is idle */ ret = readl_poll_timeout(adc_dev->reg_base + MT6577_AUXADC_CON2, val, ((val & MT6577_AUXADC_STA) == 0), MT6577_AUXADC_SLEEP_US, MT6577_AUXADC_TIMEOUT_US); if (ret < 0) { dev_err(indio_dev->dev.parent, "wait for auxadc idle time out\n"); goto err_timeout; } /* read channel and make sure ready bit == 1 */ ret = readl_poll_timeout(reg_channel, val, ((val & MT6577_AUXADC_RDY0) != 0), MT6577_AUXADC_SLEEP_US, MT6577_AUXADC_TIMEOUT_US); if (ret < 0) { dev_err(indio_dev->dev.parent, "wait for channel[%d] data ready time out\n", chan->channel); goto err_timeout; } /* read data */ val = readl(reg_channel) & MT6577_AUXADC_DAT_MASK; mutex_unlock(&adc_dev->lock); return val; err_timeout: mutex_unlock(&adc_dev->lock); return -ETIMEDOUT; } static int mt6577_auxadc_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long info) { switch (info) { case IIO_CHAN_INFO_PROCESSED: *val = mt6577_auxadc_read(indio_dev, chan); if (*val < 0) { dev_err(indio_dev->dev.parent, "failed to sample data on channel[%d]\n", chan->channel); return *val; } return IIO_VAL_INT; default: return -EINVAL; } } static const struct iio_info mt6577_auxadc_info = { .read_raw = &mt6577_auxadc_read_raw, }; static int __maybe_unused mt6577_auxadc_resume(struct device *dev) { struct iio_dev *indio_dev = dev_get_drvdata(dev); struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev); int ret; ret = clk_prepare_enable(adc_dev->adc_clk); if (ret) { pr_err("failed to enable auxadc clock\n"); return ret; } mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC, MT6577_AUXADC_PDN_EN, 0); mdelay(MT6577_AUXADC_POWER_READY_MS); return 0; } static int __maybe_unused mt6577_auxadc_suspend(struct device *dev) { struct iio_dev *indio_dev = dev_get_drvdata(dev); struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev); mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC, 0, MT6577_AUXADC_PDN_EN); clk_disable_unprepare(adc_dev->adc_clk); return 0; } static int mt6577_auxadc_probe(struct platform_device *pdev) { struct mt6577_auxadc_device *adc_dev; unsigned long adc_clk_rate; struct resource *res; struct iio_dev *indio_dev; int ret; indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc_dev)); if (!indio_dev) return -ENOMEM; adc_dev = iio_priv(indio_dev); indio_dev->dev.parent = &pdev->dev; indio_dev->name = dev_name(&pdev->dev); indio_dev->info = &mt6577_auxadc_info; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = mt6577_auxadc_iio_channels; indio_dev->num_channels = ARRAY_SIZE(mt6577_auxadc_iio_channels); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); adc_dev->reg_base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(adc_dev->reg_base)) { dev_err(&pdev->dev, "failed to get auxadc base address\n"); return PTR_ERR(adc_dev->reg_base); } adc_dev->adc_clk = devm_clk_get(&pdev->dev, "main"); if (IS_ERR(adc_dev->adc_clk)) { dev_err(&pdev->dev, "failed to get auxadc clock\n"); return PTR_ERR(adc_dev->adc_clk); } ret = clk_prepare_enable(adc_dev->adc_clk); if (ret) { dev_err(&pdev->dev, "failed to enable auxadc clock\n"); return ret; } adc_clk_rate = clk_get_rate(adc_dev->adc_clk); if (!adc_clk_rate) { ret = -EINVAL; dev_err(&pdev->dev, "null clock rate\n"); goto err_disable_clk; } mutex_init(&adc_dev->lock); mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC, MT6577_AUXADC_PDN_EN, 0); mdelay(MT6577_AUXADC_POWER_READY_MS); platform_set_drvdata(pdev, indio_dev); ret = iio_device_register(indio_dev); if (ret < 0) { dev_err(&pdev->dev, "failed to register iio device\n"); goto err_power_off; } return 0; err_power_off: mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC, 0, MT6577_AUXADC_PDN_EN); err_disable_clk: clk_disable_unprepare(adc_dev->adc_clk); return ret; } static int mt6577_auxadc_remove(struct platform_device *pdev) { struct iio_dev *indio_dev = platform_get_drvdata(pdev); struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev); iio_device_unregister(indio_dev); mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC, 0, MT6577_AUXADC_PDN_EN); clk_disable_unprepare(adc_dev->adc_clk); return 0; } static SIMPLE_DEV_PM_OPS(mt6577_auxadc_pm_ops, mt6577_auxadc_suspend, mt6577_auxadc_resume); static const struct of_device_id mt6577_auxadc_of_match[] = { { .compatible = "mediatek,mt2701-auxadc", }, { .compatible = "mediatek,mt7622-auxadc", }, { .compatible = "mediatek,mt8173-auxadc", }, { } }; MODULE_DEVICE_TABLE(of, mt6577_auxadc_of_match); static struct platform_driver mt6577_auxadc_driver = { .driver = { .name = "mt6577-auxadc", .of_match_table = mt6577_auxadc_of_match, .pm = &mt6577_auxadc_pm_ops, }, .probe = mt6577_auxadc_probe, .remove = mt6577_auxadc_remove, }; module_platform_driver(mt6577_auxadc_driver); MODULE_AUTHOR("Zhiyong Tao "); MODULE_DESCRIPTION("MTK AUXADC Device Driver"); MODULE_LICENSE("GPL v2");