Re: [PATCH v4 2/3] iio: adc: mt2701: Add Mediatek auxadc driver for mt2701.

From: zhiyong tao
Date: Wed Jul 20 2016 - 02:25:00 EST

Next message: Lukas Wunner: "Re: [PATCH v2 02/10] driver core: Functional dependencies tracking support"
Previous message: Reizer, Eyal: "RE: linux-next: build warning after merge of the wireless-drivers-next tree"
In reply to: zhiyong tao: "Re: [PATCH v4 2/3] iio: adc: mt2701: Add Mediatek auxadc driver for mt2701."
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

On Wed, 2016-07-20 at 14:02 +0800, zhiyong tao wrote:
> On Mon, 2016-07-18 at 18:12 +0100, Jonathan Cameron wrote:
> > On 11/07/16 07:39, 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>
> > Looks good to me. Couple of really minor points / questions inline...
> >
> > Just one thing to confirm... (you probably already answered this!)
> > What are the units of the voltage channels?
> >
> > Jonathan
>
> The units of the voltage channels are mv.
>
> > > ---
> > > drivers/iio/adc/Kconfig | 13 ++
> > > drivers/iio/adc/Makefile | 1 +
> > > drivers/iio/adc/mt6577_auxadc.c | 294 +++++++++++++++++++++++++++++++++++++++
> > > 3 files changed, 308 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..c7cc901
> > > --- /dev/null
> > > +++ b/drivers/iio/adc/mt6577_auxadc.c
> > > @@ -0,0 +1,294 @@
> > > +/*
> > > + * 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);
> > > +
> > > + 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);
> > > +
> > > + val = readl(adc_dev->reg_base + MT6577_AUXADC_MISC);
> > > + if ((val & MT6577_AUXADC_PDN_EN) == 0) {
> > That's a high level of paranoia... Any reason to believe this might fail?
>
> Someone reviews the code and gives a suggestion to power off chenck.
> If auxadc clk is off in the case, we can not write MT6577_AUXADC_PDN_EN
> in MT6577_AUXADC_MISC. So it may cause to enable auxadc power failed.
>

sorry, I have searched the previous versions.
I found that I misunderstand the intention.
The power on failed checked will be removed in the next version.

> > > + dev_err(&pdev->dev, "failed to enable auxadc power!\n");
> > > + goto err_disable_clk;
> > > + }
> > > +
> > > + platform_set_drvdata(pdev, indio_dev);
> > > +
> > > + ret = iio_device_register(indio_dev);
> > > + if (ret < 0) {
> > I'd have slightly preferred that this error unwind block was also
> > moved to on a goto. Makes it easier to review as the error block then
> > matches remove (with expected differences!) Really small point however.
>
> I will update this in next version.
>
> >
> > > + dev_err(&pdev->dev, "failed to register iio device!\n");
> > > + val = readl(adc_dev->reg_base + MT6577_AUXADC_MISC);
> > > + val &= ~MT6577_AUXADC_PDN_EN;
> > > + writel(val, adc_dev->reg_base + MT6577_AUXADC_MISC);
> > > + goto err_disable_clk;
> > > + }
> > > +
> > > + return 0;
> > > +
> > > +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");
> > >
> >
>

Next message: Lukas Wunner: "Re: [PATCH v2 02/10] driver core: Functional dependencies tracking support"
Previous message: Reizer, Eyal: "RE: linux-next: build warning after merge of the wireless-drivers-next tree"
In reply to: zhiyong tao: "Re: [PATCH v4 2/3] iio: adc: mt2701: Add Mediatek auxadc driver for mt2701."
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]