Re: [PATCH v9 5/5] IIO: Ingenic JZ47xx: Add touchscreen mode.

From: Jonathan Cameron
Date: Mon Jul 20 2020 - 05:52:05 EST

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In reply to: Artur Rojek: "[PATCH v9 5/5] IIO: Ingenic JZ47xx: Add touchscreen mode."
Next in thread: Artur Rojek: "[PATCH v9 4/5] dt-bindings: iio/adc: Add touchscreen idx for JZ47xx SoC ADC"
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On Sun, 19 Jul 2020 22:53:07 +0200
Artur Rojek <contact@xxxxxxxxxxxxxx> wrote:

> The SADC component in JZ47xx SoCs provides support for touchscreen
> operations (pen position and pen down pressure) in single-ended and
> differential modes.
>
> 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.
>
> 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.
>
> JZ4770 and later SoCs introduce a low-level command feature. With it, up
> to 32 commands can be programmed, each one corresponding to a sampling
> job. It allows to change the low-voltage reference, the high-voltage
> reference, have them connected to VCC, GND, or one of the X-/X+ or Y-/Y+
> pins.
>
> This patch introduces support for 6 stream-capable channels:
> - channel #0 samples X+/GND
> - channel #1 samples Y+/GND
> - channel #2 samples X-/GND
> - channel #3 samples Y-/GND
> - channel #4 samples X+/X-
> - channel #5 samples Y+/Y-
>
> Being able to sample X-/GND and Y-/GND is useful on some devices, where
> one joystick is connected to the X+/Y+ pins, and a second joystick is
> connected to the X-/Y- pins.
>
> All the boards which probe this driver have the interrupt provided from
> Device Tree, with no need to handle a case where the IRQ was not provided.
>
> Co-developed-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> Signed-off-by: Artur Rojek <contact@xxxxxxxxxxxxxx>

For this set I've created an immutable branch to allow the option of
Dmitry pulling it into input given the binding for the joystick
set is dependent on a patch in here. Doesn't matter if not though,
this just gives the option.

Immutable branch:
https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git ib-5.8-jz47xx-ts

Merged that into the togreg branch of iio.git and pushed out as testing or
the autobuilders to play with it.

Thanks,

Jonathan

> ---
>
> 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
>
> v4: clarify irq provider source in the patch description
>
> v5: no change
>
> v6: - correct the spelling of Device Tree and IRQ in commit message
> - don't omit trailing commas from initializer lists
> - error check `clk_enable`
> - remove redundant `dev_err` from `platform_get_irq` error check
>
> v7: no change
>
> v8: add support for ADCMD low-level command feature
>
> v9: replace IIO_POSITIONRELATIVE with IIO_VOLTAGE for touchscreen
> channels
>
> drivers/iio/adc/Kconfig | 1 +
> drivers/iio/adc/ingenic-adc.c | 250 +++++++++++++++++++++++++++++++++-
> 2 files changed, 249 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index ff3569635ce0..5b57437cef75 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -500,6 +500,7 @@ 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 16fc0974c65c..c5b01766513d 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>
> @@ -20,19 +22,46 @@
> #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
> +#define JZ_ADC_REG_ADCMD 0x24
> #define JZ_ADC_REG_ADCLK 0x28
>
> #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_SAMPLE_NUM(n) ((n) << 10)
> +#define JZ_ADC_REG_CFG_PULL_UP(n) ((n) << 16)
> +#define JZ_ADC_REG_CFG_CMD_SEL BIT(22)
> +#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
> #define JZ4770_ADC_REG_ADCLK_CLKDIVMS_LSB 16
>
> +#define JZ_ADC_REG_ADCMD_YNADC BIT(7)
> +#define JZ_ADC_REG_ADCMD_YPADC BIT(8)
> +#define JZ_ADC_REG_ADCMD_XNADC BIT(9)
> +#define JZ_ADC_REG_ADCMD_XPADC BIT(10)
> +#define JZ_ADC_REG_ADCMD_VREFPYP BIT(11)
> +#define JZ_ADC_REG_ADCMD_VREFPXP BIT(12)
> +#define JZ_ADC_REG_ADCMD_VREFPXN BIT(13)
> +#define JZ_ADC_REG_ADCMD_VREFPAUX BIT(14)
> +#define JZ_ADC_REG_ADCMD_VREFPVDD33 BIT(15)
> +#define JZ_ADC_REG_ADCMD_VREFNYN BIT(16)
> +#define JZ_ADC_REG_ADCMD_VREFNXP BIT(17)
> +#define JZ_ADC_REG_ADCMD_VREFNXN BIT(18)
> +#define JZ_ADC_REG_ADCMD_VREFAUX BIT(19)
> +#define JZ_ADC_REG_ADCMD_YNGRU BIT(20)
> +#define JZ_ADC_REG_ADCMD_XNGRU BIT(21)
> +#define JZ_ADC_REG_ADCMD_XPGRU BIT(22)
> +#define JZ_ADC_REG_ADCMD_YPSUP BIT(23)
> +#define JZ_ADC_REG_ADCMD_XNSUP BIT(24)
> +#define JZ_ADC_REG_ADCMD_XPSUP BIT(25)
> +
> #define JZ_ADC_AUX_VREF 3300
> #define JZ_ADC_AUX_VREF_BITS 12
> #define JZ_ADC_BATTERY_LOW_VREF 2500
> @@ -44,6 +73,14 @@
> #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 {
> @@ -69,6 +106,61 @@ struct ingenic_adc {
> bool low_vref_mode;
> };
>
> +static void ingenic_adc_set_adcmd(struct iio_dev *iio_dev, unsigned long mask)
> +{
> + struct ingenic_adc *adc = iio_priv(iio_dev);
> +
> + mutex_lock(&adc->lock);
> +
> + /* Init ADCMD */
> + readl(adc->base + JZ_ADC_REG_ADCMD);
> +
> + if (mask & 0x3) {
> + /* Second channel (INGENIC_ADC_TOUCH_YP): sample YP vs. GND */
> + writel(JZ_ADC_REG_ADCMD_XNGRU
> + | JZ_ADC_REG_ADCMD_VREFNXN | JZ_ADC_REG_ADCMD_VREFPVDD33
> + | JZ_ADC_REG_ADCMD_YPADC,
> + adc->base + JZ_ADC_REG_ADCMD);
> +
> + /* First channel (INGENIC_ADC_TOUCH_XP): sample XP vs. GND */
> + writel(JZ_ADC_REG_ADCMD_YNGRU
> + | JZ_ADC_REG_ADCMD_VREFNYN | JZ_ADC_REG_ADCMD_VREFPVDD33
> + | JZ_ADC_REG_ADCMD_XPADC,
> + adc->base + JZ_ADC_REG_ADCMD);
> + }
> +
> + if (mask & 0xc) {
> + /* Fourth channel (INGENIC_ADC_TOUCH_YN): sample YN vs. GND */
> + writel(JZ_ADC_REG_ADCMD_XNGRU
> + | JZ_ADC_REG_ADCMD_VREFNXN | JZ_ADC_REG_ADCMD_VREFPVDD33
> + | JZ_ADC_REG_ADCMD_YNADC,
> + adc->base + JZ_ADC_REG_ADCMD);
> +
> + /* Third channel (INGENIC_ADC_TOUCH_XN): sample XN vs. GND */
> + writel(JZ_ADC_REG_ADCMD_YNGRU
> + | JZ_ADC_REG_ADCMD_VREFNYN | JZ_ADC_REG_ADCMD_VREFPVDD33
> + | JZ_ADC_REG_ADCMD_XNADC,
> + adc->base + JZ_ADC_REG_ADCMD);
> + }
> +
> + if (mask & 0x30) {
> + /* Sixth channel (INGENIC_ADC_TOUCH_YD): sample YP vs. YN */
> + writel(JZ_ADC_REG_ADCMD_VREFNYN | JZ_ADC_REG_ADCMD_VREFPVDD33
> + | JZ_ADC_REG_ADCMD_YPADC,
> + adc->base + JZ_ADC_REG_ADCMD);
> +
> + /* Fifth channel (INGENIC_ADC_TOUCH_XD): sample XP vs. XN */
> + writel(JZ_ADC_REG_ADCMD_VREFNXN | JZ_ADC_REG_ADCMD_VREFPVDD33
> + | JZ_ADC_REG_ADCMD_XPADC,
> + adc->base + JZ_ADC_REG_ADCMD);
> + }
> +
> + /* We're done */
> + writel(0, adc->base + JZ_ADC_REG_ADCMD);
> +
> + mutex_unlock(&adc->lock);
> +}
> +
> static void ingenic_adc_set_config(struct ingenic_adc *adc,
> uint32_t mask,
> uint32_t val)
> @@ -288,6 +380,72 @@ static const struct iio_chan_spec jz4740_channels[] = {
> };
>
> static const struct iio_chan_spec jz4770_channels[] = {
> + {
> + .type = IIO_VOLTAGE,
> + .indexed = 1,
> + .channel = INGENIC_ADC_TOUCH_XP,
> + .scan_index = 0,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 12,
> + .storagebits = 16,
> + },
> + },
> + {
> + .type = IIO_VOLTAGE,
> + .indexed = 1,
> + .channel = INGENIC_ADC_TOUCH_YP,
> + .scan_index = 1,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 12,
> + .storagebits = 16,
> + },
> + },
> + {
> + .type = IIO_VOLTAGE,
> + .indexed = 1,
> + .channel = INGENIC_ADC_TOUCH_XN,
> + .scan_index = 2,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 12,
> + .storagebits = 16,
> + },
> + },
> + {
> + .type = IIO_VOLTAGE,
> + .indexed = 1,
> + .channel = INGENIC_ADC_TOUCH_YN,
> + .scan_index = 3,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 12,
> + .storagebits = 16,
> + },
> + },
> + {
> + .type = IIO_VOLTAGE,
> + .indexed = 1,
> + .channel = INGENIC_ADC_TOUCH_XD,
> + .scan_index = 4,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 12,
> + .storagebits = 16,
> + },
> + },
> + {
> + .type = IIO_VOLTAGE,
> + .indexed = 1,
> + .channel = INGENIC_ADC_TOUCH_YD,
> + .scan_index = 5,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 12,
> + .storagebits = 16,
> + },
> + },
> {
> .extend_name = "aux",
> .type = IIO_VOLTAGE,
> @@ -491,13 +649,89 @@ static const struct iio_info ingenic_adc_info = {
> .of_xlate = ingenic_adc_of_xlate,
> };
>
> +static int ingenic_adc_buffer_enable(struct iio_dev *iio_dev)
> +{
> + struct ingenic_adc *adc = iio_priv(iio_dev);
> + int ret;
> +
> + ret = clk_enable(adc->clk);
> + if (ret) {
> + dev_err(iio_dev->dev.parent, "Failed to enable clock: %d\n",
> + ret);
> + return ret;
> + }
> +
> + /* 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_set_config(adc, JZ_ADC_REG_CFG_CMD_SEL,
> + JZ_ADC_REG_CFG_CMD_SEL);
> + ingenic_adc_set_adcmd(iio_dev, iio_dev->active_scan_mask[0]);
> +
> + 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);
> +
> + ingenic_adc_set_config(adc, JZ_ADC_REG_CFG_CMD_SEL, 0);
> +
> + 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);
> + unsigned long mask = iio_dev->active_scan_mask[0];
> + unsigned int i;
> + u32 tdat[3];
> +
> + for (i = 0; i < ARRAY_SIZE(tdat); mask >>= 2, i++) {
> + if (mask & 0x3)
> + tdat[i] = readl(adc->base + JZ_ADC_REG_ADTCH);
> + else
> + tdat[i] = 0;
> + }
> +
> + 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)
> @@ -512,6 +746,17 @@ 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);
> + if (irq < 0)
> + 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);
> @@ -551,7 +796,8 @@ 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 = soc_data->channels;
> iio_dev->num_channels = soc_data->num_channels;
> iio_dev->info = &ingenic_adc_info;

Next message: Pavel Machek: "Re: [PATCH v31 01/12] leds: multicolor: Introduce a multicolor class definition"
Previous message: Amit Kucheria: "Re: [PATCH v4 7/7] drivers: thermal: tsens: add set_trip support for 8960"
In reply to: Artur Rojek: "[PATCH v9 5/5] IIO: Ingenic JZ47xx: Add touchscreen mode."
Next in thread: Artur Rojek: "[PATCH v9 4/5] dt-bindings: iio/adc: Add touchscreen idx for JZ47xx SoC ADC"
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