Am Samstag, 12. Juli 2014, 15:35:04 schrieb Jonathan Cameron:
> On 09/07/14 11:22, Heiko Stübner wrote:
> > The ADC is a 3-channel signal-ended 10-bit Successive Approximation
> > Register (SAR) A/D Converter. It uses the supply and ground as its
> > reference and converts the analog input signal into 10-bit binary digital
> > codes.
> >
> > Signed-off-by: Heiko Stuebner <heiko@xxxxxxxxx>
>
> Very nice. One utterly trivial comment inline that doesn't really
> bother me (made the review take a good 10 seconds longer than it
> otherwise would have done!)
>
> Ah, and as my build tests (x86_64) just finished, a build issue:
>
> drivers/iio/adc/rockchip_saradc.c:65:17: error: undefined identifier
> 'writel_relaxed' drivers/iio/adc/rockchip_saradc.c:73:25: error: undefined
> identifier 'writel_relaxed' drivers/iio/adc/rockchip_saradc.c:99:9: error:
> undefined identifier 'writel_relaxed'
>
> I can't immediately identify if there is a CONFIG element to indicate
> the availability of the relaxed form. Anyone else know?
taking a spi driver from another architecture (spi_qup), I see
config SPI_QUP
depends on ARCH_QCOM || (ARM && COMPILE_TEST)
A fix Mark Brown did for the actual rockchip spi driver does
config SPI_ROCKCHIP
depends on ARM || ARM64 || AVR32 || HEXAGON || MIPS || SUPERH
so I guess the saradc also could do one of the two ... preferences? :-)
> I'm in two minds on whether the binding is obvous enough to take without
> a device-tree maintainer ack. I'll let it sit for a bit - perhaps
> even the standard 3 weeks (please repost with the typos fixed though)
> and see if anyone want to comment.
ok, so I'll repost the two patches, fixing the typos and Kconfig and changing
the of_property_read_u32 behaviour.
Heiko
>
> Jonathan
>
> > ---
> >
> > changes since v2:
> > - address more comments from Peter Meerwald
> >
> > mainly the missing info_mask_shared_by_type element
> >
> > changes since v1:
> > - address comments from Peter Meerwald
> >
> > drivers/iio/adc/Kconfig | 10 ++
> >
> > drivers/iio/adc/Makefile | 1 +
> > drivers/iio/adc/rockchip_saradc.c | 314
> > ++++++++++++++++++++++++++++++++++++++ 3 files changed, 325
> > insertions(+)
> > create mode 100644 drivers/iio/adc/rockchip_saradc.c
> >
> > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> > index a80d236..5d36bdb 100644
> > --- a/drivers/iio/adc/Kconfig
> > +++ b/drivers/iio/adc/Kconfig
> > @@ -187,6 +187,16 @@ config NAU7802
> >
> > To compile this driver as a module, choose M here: the
> > module will be called nau7802.
> >
> > +config ROCKCHIP_SARADC
> > + tristate "Rockchip SARADC driver"
> > + depends on ARCH_ROCKCHIP || (OF && COMPILE_TEST)
> > + help
> > + Say yes here to build support for the SARADC found in SoCs from
> > + Rockchip.
> > +
> > + To compile this driver as a module, choose M here: the
> > + module will be called rockchip_saradc.
> > +
> >
> > config TI_ADC081C
> >
> > tristate "Texas Instruments ADC081C021/027"
> > depends on I2C
> >
> > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> > index 9d60f2d..8e2932d 100644
> > --- a/drivers/iio/adc/Makefile
> > +++ b/drivers/iio/adc/Makefile
> > @@ -20,6 +20,7 @@ obj-$(CONFIG_MCP320X) += mcp320x.o
> >
> > obj-$(CONFIG_MCP3422) += mcp3422.o
> > obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o
> > obj-$(CONFIG_NAU7802) += nau7802.o
> >
> > +obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
> >
> > obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
> > obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
> > obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o
> >
> > diff --git a/drivers/iio/adc/rockchip_saradc.c
> > b/drivers/iio/adc/rockchip_saradc.c new file mode 100644
> > index 0000000..8fc5867
> > --- /dev/null
> > +++ b/drivers/iio/adc/rockchip_saradc.c
> > @@ -0,0 +1,314 @@
> > +/*
> > + * 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;
> > + int vref_mv;
> > + 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);
> > +
> > + switch (mask) {
> > + case IIO_CHAN_INFO_RAW:
> > + mutex_lock(&indio_dev->mlock);
> > +
> > + /* Select the channel to be used and trigger conversion */
> > + writel_relaxed(0x08, info->regs + SARADC_DLY_PU_SOC);
> > + 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:
> > + *val = info->vref_mv;
> > + *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 = -ENODEV;
> > + int irq;
> > + u32 rate;
> > +
> > + if (!np)
> > + return ret;
> > +
> > + 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_request_and_ioremap(&pdev->dev, mem);
> > + if (!info->regs)
> > + return -ENOMEM;
> > +
> > + 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;
> > + }
> > +
> > + init_completion(&info->completion);
> > +
> > + 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 */
> > + if (of_property_read_u32(np, "clock-frequency", &rate))
> > + rate = 1000000;
>
> I'd have a very slight preference of checking for an error rather
> than simply non zero (i.e. < 0). The function is clearly
> documented as returning 0 for success however. The only
> reason I carred is that I had to check that rather than relying
> on the tighter standard convention!
>
> > +
> > + ret = clk_set_rate(info->clk, rate);
> > + if (ret) {
> > + dev_err(&pdev->dev, "failed to set adc clk rate, %d\n", ret);
> > + return ret;
> > + }
> > +
> > + ret = regulator_enable(info->vref);
> > + if (ret) {
> > + dev_err(&pdev->dev, "failed to enable vref regulator\n");
> > + return ret;
> > + }
> > +
> > + ret = regulator_get_voltage(info->vref);
> > + if (ret < 0) {
> > + dev_err(&pdev->dev, "failed to get regulator voltage\n");
> > + goto err_reg_voltage;
> > + }
> > + info->vref_mv = ret / 1000;
> > +
> > + ret = clk_prepare_enable(info->pclk);
> > + if (ret) {
> > + dev_err(&pdev->dev, "failed to enable pclk\n");
> > + goto err_reg_voltage;
> > + }
> > +
> > + ret = clk_prepare_enable(info->clk);
> > + if (ret) {
> > + 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);
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