On 21/07/16 09:17, Zhiyong Tao wrote: > Add Mediatek auxadc driver based on iio. > It will register a device in iio and support iio. > So thermal can read auxadc channel to sample data by iio device. > It is tested successfully on mt2701 platform. > Mt8173 and mt6577 platforms are not tested. > But the expectation is compatible. > > Signed-off-by: Zhiyong Tao <zhiyong.tao@xxxxxxxxxxxx> As you are re spinning anyway to address Peter's comments one more minor point from me inline Shaping up to be a nice little driver. Jonathan > --- > drivers/iio/adc/Kconfig | 13 ++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/mt6577_auxadc.c | 289 +++++++++++++++++++++++++++++++++++++++ > 3 files changed, 303 insertions(+) > create mode 100644 drivers/iio/adc/mt6577_auxadc.c > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 25378c5..14929fc 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -305,6 +305,19 @@ config MCP3422 > This driver can also be built as a module. If so, the module will be > called mcp3422. > > +config MEDIATEK_MT6577_AUXADC > + tristate "MediaTek AUXADC driver" > + depends on ARCH_MEDIATEK || COMPILE_TEST > + depends on HAS_IOMEM > + help > + Say yes here to enable support for MediaTek mt65xx AUXADC. > + > + The driver supports immediate mode operation to read from one of sixteen > + channels (external or internal). > + > + This driver can also be built as a module. If so, the module will be > + called mt6577_auxadc. > + > config MEN_Z188_ADC > tristate "MEN 16z188 ADC IP Core support" > depends on MCB > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index 38638d4..8306347 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -30,6 +30,7 @@ obj-$(CONFIG_MAX1027) += max1027.o > obj-$(CONFIG_MAX1363) += max1363.o > obj-$(CONFIG_MCP320X) += mcp320x.o > obj-$(CONFIG_MCP3422) += mcp3422.o > +obj-$(CONFIG_MEDIATEK_MT6577_AUXADC) += mt6577_auxadc.o > obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o > obj-$(CONFIG_MXS_LRADC) += mxs-lradc.o > obj-$(CONFIG_NAU7802) += nau7802.o > diff --git a/drivers/iio/adc/mt6577_auxadc.c b/drivers/iio/adc/mt6577_auxadc.c > new file mode 100644 > index 0000000..6240236 > --- /dev/null > +++ b/drivers/iio/adc/mt6577_auxadc.c > @@ -0,0 +1,289 @@ > +/* > + * Copyright (c) 2016 MediaTek Inc. > + * Author: Zhiyong Tao <zhiyong.tao@xxxxxxxxxxxx> > + * > + * 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 <linux/clk.h> > +#include <linux/delay.h> > +#include <linux/err.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/of_device.h> > +#include <linux/platform_device.h> > +#include <linux/iopoll.h> > +#include <linux/io.h> > +#include <linux/iio/iio.h> > + > +/* 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 int mt6577_auxadc_read(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan) > +{ > + u32 rawdata, 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); > + > + val = readl(adc_dev->reg_base + MT6577_AUXADC_CON1); > + val &= ~(1 << chan->channel); > + writel(val, adc_dev->reg_base + MT6577_AUXADC_CON1); > + > + /* 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); > + > + mutex_unlock(&adc_dev->lock); I'd prefer a goto taking us to the mutex unlock a the end of the driver. Makes it harder to get editing this driver and breaking the locking wrong in the future! > + > + return -ETIMEDOUT; > + } > + > + /* set bit to trigger sample */ > + val = readl(adc_dev->reg_base + MT6577_AUXADC_CON1); > + val |= 1 << chan->channel; > + writel(val, adc_dev->reg_base + MT6577_AUXADC_CON1); > + > + /* 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"); > + > + mutex_unlock(&adc_dev->lock); > + > + return -ETIMEDOUT; > + } > + > + /* 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); > + > + mutex_unlock(&adc_dev->lock); > + > + return -ETIMEDOUT; > + } > + > + /* read data */ > + rawdata = readl(reg_channel) & MT6577_AUXADC_DAT_MASK; > + > + mutex_unlock(&adc_dev->lock); > + > + return rawdata; > +} > + > +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 = { > + .driver_module = THIS_MODULE, > + .read_raw = &mt6577_auxadc_read_raw, > +}; > + > +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; > + u32 val; > + > + 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) { > + dev_err(&pdev->dev, "null clock rate!\n"); > + goto err_disable_clk; > + } > + > + mutex_init(&adc_dev->lock); > + > + val = readl(adc_dev->reg_base + MT6577_AUXADC_MISC); > + val |= MT6577_AUXADC_PDN_EN; > + writel(val, adc_dev->reg_base + MT6577_AUXADC_MISC); > + 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: > + val = readl(adc_dev->reg_base + MT6577_AUXADC_MISC); > + val &= ~MT6577_AUXADC_PDN_EN; > + writel(val, adc_dev->reg_base + MT6577_AUXADC_MISC); > +err_disable_clk: > + clk_disable_unprepare(adc_dev->adc_clk); > + return -EINVAL; > +} > + > +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); > + u32 val; > + > + iio_device_unregister(indio_dev); > + > + val = readl(adc_dev->reg_base + MT6577_AUXADC_MISC); > + val &= ~MT6577_AUXADC_PDN_EN; > + writel(val, adc_dev->reg_base + MT6577_AUXADC_MISC); > + > + clk_disable_unprepare(adc_dev->adc_clk); > + > + return 0; > +} > + > +static const struct of_device_id mt6577_auxadc_of_match[] = { > + { .compatible = "mediatek,mt2701-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, > + }, > + .probe = mt6577_auxadc_probe, > + .remove = mt6577_auxadc_remove, > +}; > +module_platform_driver(mt6577_auxadc_driver); > + > +MODULE_AUTHOR("Zhiyong Tao <zhiyong.tao@xxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("MTK AUXADC Device Driver"); > +MODULE_LICENSE("GPL v2"); > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html