Re: [PATCH] iio: adc: rockchip_saradc: add support for rk3066-tsadc variant

Heiko Stübner
2014-09-03T10:11:49Z

Am Mittwoch, 3. September 2014, 00:20:58 schrieb Hartmut Knaack:
> Heiko Stübner schrieb:
> > Older Rockchip SoCs, at least the rk3066, used a slightly modified saradc
> > for temperature measurements. This so called tsadc does not contain any
> > active parts like temperature interrupts and only supports polling the
> > current temperature. The returned voltage can then be converted by a
> > suitable thermal driver to and actual temperature and used for thermal
> > handling.
> >
> > Signed-off-by: Heiko Stuebner <heiko@sntech.de>
> > ---
>
> Looks mostly good to me, just some minor style issues inline.
>
> > This is a different IP than the rk3288-tsadc Ceasar provided a driver for.
> > As the commit messages states, the one used on the rk3066 is just a
> > saradc,
> > while the new tsadc in the rk3288 contains active components for thermal
> > handling.
> >
> > A working example using the pending iio-thermal driver can found on
> > https://github.com/mmind/linux-rockchip/commit/c07e02f069d9677d489f2541766
> > 19fae36f2aad0>
> > .../bindings/iio/adc/rockchip-saradc.txt | 2 +-
> > drivers/iio/adc/rockchip_saradc.c | 62
> > +++++++++++++++++----- 2 files changed, 50 insertions(+), 14
> > deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt
> > b/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt index
> > 5d3ec1d..a9a5fe1 100644
> > --- a/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt
> > +++ b/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt
> > @@ -1,7 +1,7 @@
> >
> > Rockchip Successive Approximation Register (SAR) A/D Converter bindings
> >
> > Required properties:
> > -- compatible: Should be "rockchip,saradc"
> > +- compatible: Should be "rockchip,saradc" or "rockchip,rk3066-tsadc"
> >
> > - reg: physical base address of the controller and length of memory
> > mapped
> >
> > region.
> >
> > - interrupts: The interrupt number to the cpu. The interrupt specifier
> > format>
> > diff --git a/drivers/iio/adc/rockchip_saradc.c
> > b/drivers/iio/adc/rockchip_saradc.c index e074a0b..7effada 100644
> > --- a/drivers/iio/adc/rockchip_saradc.c
> > +++ b/drivers/iio/adc/rockchip_saradc.c
> > @@ -18,13 +18,13 @@
> >
> > #include <linux/interrupt.h>
> > #include <linux/io.h>
> > #include <linux/of.h>
> >
> > +#include <linux/of_device.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)
> >
> > @@ -38,15 +38,22 @@
> >
> > #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_data {
> > + int num_bits;
> > + const struct iio_chan_spec *channels;
> > + int num_channels;
> > + unsigned long clk_rate;
> > +};
> > +
> >
> > struct rockchip_saradc {
> >
> > void __iomem *regs;
> > struct clk *pclk;
> > struct clk *clk;
> > struct completion completion;
> > struct regulator *vref;
> >
> > + const struct rockchip_saradc_data *data;
> >
> > u16 last_val;
> >
> > };
>
> The alignment of the whole block should be adjusted to fit with the new
> element.

Hmm, I'm not sure if this should be in this patch, as changing the indentation
is more or less an unrelated change which makes recognizing the actual change
of adding the data field harder to see.

It could be a second patch on top to adapt the formating, but this also sounds
a bit like overkill.

In any case I guess I'll wait for Jonathan to decide how he likes this to be
approached.

> > @@ -90,7 +97,7 @@ static int rockchip_saradc_read_raw(struct iio_dev
> > *indio_dev,>
> > }
> >
> > *val = ret / 1000;
> >
> > - *val2 = SARADC_BITS;
> > + *val2 = info->data->num_bits;
> >
> > return IIO_VAL_FRACTIONAL_LOG2;
> >
> > default:
> > return -EINVAL;
> >
> > @@ -103,7 +110,7 @@ static irqreturn_t rockchip_saradc_isr(int irq, void
> > *dev_id)>
> > /* Read value */
> > info->last_val = readl_relaxed(info->regs + SARADC_DATA);
> >
> > - info->last_val &= SARADC_DATA_MASK;
> > + info->last_val &= BIT(info->data->num_bits) - 1;
>
> I think using GENMASK would reflect the intention better, that you want to
> mask out your data.

I didn't know GENMASK before, so thanks for the pointer .. this looks quite
cool :-)

> > /* Clear irq & power down adc */
> > writel_relaxed(0, info->regs + SARADC_CTRL);
> >
> > @@ -133,12 +140,44 @@ static const struct iio_chan_spec
> > rockchip_saradc_iio_channels[] = {>
> > ADC_CHANNEL(2, "adc2"),
> >
> > };
> >
> > +static const struct rockchip_saradc_data saradc_data = {
> > + .num_bits = 10,
> > + .channels = rockchip_saradc_iio_channels,
> > + .num_channels = ARRAY_SIZE(rockchip_saradc_iio_channels),
> > + .clk_rate = 1000000,
> > +};
> > +
> > +static const struct iio_chan_spec rockchip_rk3066_tsadc_iio_channels[] =
> > {
> > + ADC_CHANNEL(0, "adc0"),
> > + ADC_CHANNEL(1, "adc1"),
> > +};
> > +
> > +static const struct rockchip_saradc_data rk3066_tsadc_data = {
> > + .num_bits = 12,
> > + .channels = rockchip_rk3066_tsadc_iio_channels,
> > + .num_channels = ARRAY_SIZE(rockchip_rk3066_tsadc_iio_channels),
> > + .clk_rate = 50000,
> > +};
> > +
> > +static const struct of_device_id rockchip_saradc_match[] = {
> > + {
> > + .compatible = "rockchip,saradc",
> > + .data = &saradc_data,
> > + }, {
> > + .compatible = "rockchip,rk3066-tsadc",
> > + .data = &rk3066_tsadc_data,
> > + },
> > + {},
> > +};
> > +MODULE_DEVICE_TABLE(of, rockchip_saradc_match);
> > +
> >
> > 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;
> >
> > + const struct of_device_id *match;
> >
> > int ret;
> > int irq;
> >
> > @@ -152,6 +191,9 @@ static int rockchip_saradc_probe(struct
> > platform_device *pdev)>
> > }
> > info = iio_priv(indio_dev);
> >
> > + match = of_match_device(rockchip_saradc_match, &pdev->dev);
> > + info->data = match->data;
> > +
> >
> > mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > info->regs = devm_ioremap_resource(&pdev->dev, mem);
> > if (IS_ERR(info->regs))
> >
> > @@ -195,7 +237,7 @@ static int rockchip_saradc_probe(struct
> > platform_device *pdev)>
> > * Use a default of 1MHz for the converter clock.
> > * This may become user-configurable in the future.
> > */
> >
> > - ret = clk_set_rate(info->clk, 1000000);
> > + ret = clk_set_rate(info->clk, info->data->clk_rate);
> >
> > if (ret < 0) {
> >
> > dev_err(&pdev->dev, "failed to set adc clk rate, %d\n", ret);
> > return ret;
> >
> > @@ -227,8 +269,8 @@ static int rockchip_saradc_probe(struct
> > platform_device *pdev)>
> > 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);
> > + indio_dev->channels = info->data->channels;
> > + indio_dev->num_channels = info->data->num_channels;
> >
> > ret = iio_device_register(indio_dev);
> > if (ret)
> >
> > @@ -296,12 +338,6 @@ static int rockchip_saradc_resume(struct device *dev)
> >
> > 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,