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SubjectRe: [PATCH v3 3/5] IIO: Ingenic JZ47xx: Add touchscreen mode.
On Sat, 07 Mar 2020 13:58:40 +0100
Paul Cercueil <paul@crapouillou.net> wrote:

> Hi Jonathan,
>
>
> Le sam., mars 7, 2020 at 12:47, Jonathan Cameron
> <jic23@jic23.retrosnub.co.uk> a écrit :
> > On Sun, 1 Mar 2020 16:09:18 +0100
> > Artur Rojek <contact@artur-rojek.eu> wrote:
> >
> >> The SADC component in JZ47xx SoCs provides support for touchscreen
> >> operations (pen position and pen down pressure) in single-ended and
> >> differential modes.
> >>
> >> Of the known hardware to use this controller, GCW Zero and Anbernic
> >> RG-350
> >> utilize the touchscreen mode by having their joystick(s) attached
> >> to the
> >> X/Y positive/negative input pins.
> >> GCW Zero comes with a single joystick and is sufficiently handled
> >> with the
> >> currently implemented single-ended mode. Support for boards with two
> >> joysticks, where one is hooked up to Xn/Yn and the other to Xp/Yp
> >> channels
> >> will need to be provided in the future.
> >>
> >> The touchscreen component of SADC takes a significant time to
> >> stabilize
> >> after first receiving the clock and a delay of 50ms has been
> >> empirically
> >> proven to be a safe value before data sampling can begin.
> >>
> >> Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
> >> Tested-by: Paul Cercueil <paul@crapouillou.net>
> >
> > This relies on the use of an irq that wasn't previously used. Was
> > that
> > always hooked up? If not we need to still work as before when it
> > isn't provided.
> >
> > Otherwise this looks fine to me.
>
> All the boards that probe the ingenic-adc driver have the interrupt
> provided from devicetree, yes.
Great :)

No problem then. Perhaps add a note to the patch description to say
that so no one else wonders in future.

Thanks,

Jonathan


>
> Cheers,
> -Paul
>
> >
> >> ---
> >>
> >> Changes:
> >>
> >> v2: - improve description of the touchscreen mode,
> >> - get rid of the unneeded kfifo,
> >> - drop IIO_BUFFER_CB from Kconfig,
> >> - remove extended names from the touchscreen channels
> >>
> >> v3: remove unneeded `linux/iio/kfifo_buf.h` include
> >>
> >> drivers/iio/adc/Kconfig | 1 +
> >> drivers/iio/adc/ingenic-adc.c | 109
> >> +++++++++++++++++++++++++++++++++-
> >> 2 files changed, 108 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> >> index 82e33082958c..d3fd4b6e2d47 100644
> >> --- a/drivers/iio/adc/Kconfig
> >> +++ b/drivers/iio/adc/Kconfig
> >> @@ -453,6 +453,7 @@ config INA2XX_ADC
> >> config INGENIC_ADC
> >> tristate "Ingenic JZ47xx SoCs ADC driver"
> >> depends on MIPS || COMPILE_TEST
> >> + select IIO_BUFFER
> >> help
> >> Say yes here to build support for the Ingenic JZ47xx SoCs ADC
> >> unit.
> >>
> >> diff --git a/drivers/iio/adc/ingenic-adc.c
> >> b/drivers/iio/adc/ingenic-adc.c
> >> index 7a24bc1dabe1..0dafc8d5d0d8 100644
> >> --- a/drivers/iio/adc/ingenic-adc.c
> >> +++ b/drivers/iio/adc/ingenic-adc.c
> >> @@ -8,7 +8,9 @@
> >>
> >> #include <dt-bindings/iio/adc/ingenic,adc.h>
> >> #include <linux/clk.h>
> >> +#include <linux/iio/buffer.h>
> >> #include <linux/iio/iio.h>
> >> +#include <linux/interrupt.h>
> >> #include <linux/io.h>
> >> #include <linux/iopoll.h>
> >> #include <linux/kernel.h>
> >> @@ -20,6 +22,8 @@
> >> #define JZ_ADC_REG_CFG 0x04
> >> #define JZ_ADC_REG_CTRL 0x08
> >> #define JZ_ADC_REG_STATUS 0x0c
> >> +#define JZ_ADC_REG_ADSAME 0x10
> >> +#define JZ_ADC_REG_ADWAIT 0x14
> >> #define JZ_ADC_REG_ADTCH 0x18
> >> #define JZ_ADC_REG_ADBDAT 0x1c
> >> #define JZ_ADC_REG_ADSDAT 0x20
> >> @@ -28,6 +32,9 @@
> >> #define JZ_ADC_REG_ENABLE_PD BIT(7)
> >> #define JZ_ADC_REG_CFG_AUX_MD (BIT(0) | BIT(1))
> >> #define JZ_ADC_REG_CFG_BAT_MD BIT(4)
> >> +#define JZ_ADC_REG_CFG_PULL_UP(n) ((n) << 16)
> >> +#define JZ_ADC_REG_CFG_SAMPLE_NUM(n) ((n) << 10)
> >> +#define JZ_ADC_REG_CFG_TOUCH_OPS_MASK (BIT(31) | GENMASK(23, 10))
> >> #define JZ_ADC_REG_ADCLK_CLKDIV_LSB 0
> >> #define JZ4725B_ADC_REG_ADCLK_CLKDIV10US_LSB 16
> >> #define JZ4770_ADC_REG_ADCLK_CLKDIV10US_LSB 8
> >> @@ -44,6 +51,14 @@
> >> #define JZ4770_ADC_BATTERY_VREF 6600
> >> #define JZ4770_ADC_BATTERY_VREF_BITS 12
> >>
> >> +#define JZ_ADC_IRQ_AUX BIT(0)
> >> +#define JZ_ADC_IRQ_BATTERY BIT(1)
> >> +#define JZ_ADC_IRQ_TOUCH BIT(2)
> >> +#define JZ_ADC_IRQ_PEN_DOWN BIT(3)
> >> +#define JZ_ADC_IRQ_PEN_UP BIT(4)
> >> +#define JZ_ADC_IRQ_PEN_DOWN_SLEEP BIT(5)
> >> +#define JZ_ADC_IRQ_SLEEP BIT(7)
> >> +
> >> struct ingenic_adc;
> >>
> >> struct ingenic_adc_soc_data {
> >> @@ -411,6 +426,28 @@ static const struct iio_info ingenic_adc_info
> >> = {
> >> };
> >>
> >> static const struct iio_chan_spec ingenic_channels[] = {
> >> + {
> >> + .type = IIO_POSITIONRELATIVE,
> >> + .indexed = 1,
> >> + .channel = INGENIC_ADC_TOUCH_XP,
> >> + .scan_index = 0,
> >> + .scan_type = {
> >> + .sign = 'u',
> >> + .realbits = 12,
> >> + .storagebits = 16
> >> + },
> >> + },
> >> + {
> >> + .type = IIO_POSITIONRELATIVE,
> >> + .indexed = 1,
> >> + .channel = INGENIC_ADC_TOUCH_YP,
> >> + .scan_index = 1,
> >> + .scan_type = {
> >> + .sign = 'u',
> >> + .realbits = 12,
> >> + .storagebits = 16
> >> + },
> >> + },
> >> {
> >> .extend_name = "aux",
> >> .type = IIO_VOLTAGE,
> >> @@ -418,6 +455,7 @@ static const struct iio_chan_spec
> >> ingenic_channels[] = {
> >> BIT(IIO_CHAN_INFO_SCALE),
> >> .indexed = 1,
> >> .channel = INGENIC_ADC_AUX,
> >> + .scan_index = -1
> >> },
> >> {
> >> .extend_name = "battery",
> >> @@ -428,6 +466,7 @@ static const struct iio_chan_spec
> >> ingenic_channels[] = {
> >> BIT(IIO_CHAN_INFO_SCALE),
> >> .indexed = 1,
> >> .channel = INGENIC_ADC_BATTERY,
> >> + .scan_index = -1
> >> },
> >> { /* Must always be last in the array. */
> >> .extend_name = "aux2",
> >> @@ -436,16 +475,69 @@ static const struct iio_chan_spec
> >> ingenic_channels[] = {
> >> BIT(IIO_CHAN_INFO_SCALE),
> >> .indexed = 1,
> >> .channel = INGENIC_ADC_AUX2,
> >> + .scan_index = -1
> >> },
> >> };
> >>
> >> +static int ingenic_adc_buffer_enable(struct iio_dev *iio_dev)
> >> +{
> >> + struct ingenic_adc *adc = iio_priv(iio_dev);
> >> +
> >> + clk_enable(adc->clk);
> >> + /* It takes significant time for the touchscreen hw to stabilize.
> >> */
> >> + msleep(50);
> >> + ingenic_adc_set_config(adc, JZ_ADC_REG_CFG_TOUCH_OPS_MASK,
> >> + JZ_ADC_REG_CFG_SAMPLE_NUM(4) |
> >> + JZ_ADC_REG_CFG_PULL_UP(4));
> >> + writew(80, adc->base + JZ_ADC_REG_ADWAIT);
> >> + writew(2, adc->base + JZ_ADC_REG_ADSAME);
> >> + writeb((u8)~JZ_ADC_IRQ_TOUCH, adc->base + JZ_ADC_REG_CTRL);
> >> + writel(0, adc->base + JZ_ADC_REG_ADTCH);
> >> + ingenic_adc_enable(adc, 2, true);
> >> +
> >> + return 0;
> >> +}
> >> +
> >> +static int ingenic_adc_buffer_disable(struct iio_dev *iio_dev)
> >> +{
> >> + struct ingenic_adc *adc = iio_priv(iio_dev);
> >> +
> >> + ingenic_adc_enable(adc, 2, false);
> >> + writeb(0xff, adc->base + JZ_ADC_REG_CTRL);
> >> + writeb(0xff, adc->base + JZ_ADC_REG_STATUS);
> >> + ingenic_adc_set_config(adc, JZ_ADC_REG_CFG_TOUCH_OPS_MASK, 0);
> >> + writew(0, adc->base + JZ_ADC_REG_ADSAME);
> >> + writew(0, adc->base + JZ_ADC_REG_ADWAIT);
> >> + clk_disable(adc->clk);
> >> +
> >> + return 0;
> >> +}
> >> +
> >> +static const struct iio_buffer_setup_ops ingenic_buffer_setup_ops
> >> = {
> >> + .postenable = &ingenic_adc_buffer_enable,
> >> + .predisable = &ingenic_adc_buffer_disable
> >> +};
> >> +
> >> +static irqreturn_t ingenic_adc_irq(int irq, void *data)
> >> +{
> >> + struct iio_dev *iio_dev = data;
> >> + struct ingenic_adc *adc = iio_priv(iio_dev);
> >> + u32 tdat;
> >> +
> >> + tdat = readl(adc->base + JZ_ADC_REG_ADTCH);
> >> + iio_push_to_buffers(iio_dev, &tdat);
> >> + writeb(JZ_ADC_IRQ_TOUCH, adc->base + JZ_ADC_REG_STATUS);
> >> +
> >> + return IRQ_HANDLED;
> >> +}
> >> +
> >> static int ingenic_adc_probe(struct platform_device *pdev)
> >> {
> >> struct device *dev = &pdev->dev;
> >> struct iio_dev *iio_dev;
> >> struct ingenic_adc *adc;
> >> const struct ingenic_adc_soc_data *soc_data;
> >> - int ret;
> >> + int irq, ret;
> >>
> >> soc_data = device_get_match_data(dev);
> >> if (!soc_data)
> >> @@ -460,6 +552,18 @@ static int ingenic_adc_probe(struct
> >> platform_device *pdev)
> >> mutex_init(&adc->aux_lock);
> >> adc->soc_data = soc_data;
> >>
> >> + irq = platform_get_irq(pdev, 0);
> >
> > Do we need a fallback path if there is no irq provided? We can't
> > break existing
> > supported devices that don't specify one.
> >
> >> + if (irq < 0) {
> >> + dev_err(dev, "Failed to get irq: %d\n", irq);
> >> + return irq;
> >> + }
> >> + ret = devm_request_irq(dev, irq, ingenic_adc_irq, 0,
> >> + dev_name(dev), iio_dev);
> >> + if (ret < 0) {
> >> + dev_err(dev, "Failed to request irq: %d\n", ret);
> >> + return ret;
> >> + }
> >> +
> >> adc->base = devm_platform_ioremap_resource(pdev, 0);
> >> if (IS_ERR(adc->base))
> >> return PTR_ERR(adc->base);
> >> @@ -499,7 +603,8 @@ static int ingenic_adc_probe(struct
> >> platform_device *pdev)
> >>
> >> iio_dev->dev.parent = dev;
> >> iio_dev->name = "jz-adc";
> >> - iio_dev->modes = INDIO_DIRECT_MODE;
> >> + iio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
> >> + iio_dev->setup_ops = &ingenic_buffer_setup_ops;
> >> iio_dev->channels = ingenic_channels;
> >> iio_dev->num_channels = ARRAY_SIZE(ingenic_channels);
> >> /* Remove AUX2 from the list of supported channels. */
> >
>
>

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