2020-07-19 20:55:03

by Artur Rojek

[permalink] [raw]
Subject: [PATCH v9 1/5] IIO: Ingenic JZ47xx: Error check clk_enable calls.

Introduce error checks for the clk_enable calls used in this driver.
As part of the changes, move clk_enable/clk_disable calls out of
ingenic_adc_set_config and into respective logic of its callers.

Signed-off-by: Artur Rojek <[email protected]>
Tested-by: Paul Cercueil <[email protected]>
---

Changes:

v6: new patch

v7: no change

v8: move `clk_disable` outside the lock

v9: remove `iio_priv_to_dev` usage

drivers/iio/adc/ingenic-adc.c | 30 ++++++++++++++++++++++++------
1 file changed, 24 insertions(+), 6 deletions(-)

diff --git a/drivers/iio/adc/ingenic-adc.c b/drivers/iio/adc/ingenic-adc.c
index 39c0a609fc94..059c2573e4a9 100644
--- a/drivers/iio/adc/ingenic-adc.c
+++ b/drivers/iio/adc/ingenic-adc.c
@@ -73,7 +73,6 @@ static void ingenic_adc_set_config(struct ingenic_adc *adc,
{
uint32_t cfg;

- clk_enable(adc->clk);
mutex_lock(&adc->lock);

cfg = readl(adc->base + JZ_ADC_REG_CFG) & ~mask;
@@ -81,7 +80,6 @@ static void ingenic_adc_set_config(struct ingenic_adc *adc,
writel(cfg, adc->base + JZ_ADC_REG_CFG);

mutex_unlock(&adc->lock);
- clk_disable(adc->clk);
}

static void ingenic_adc_enable(struct ingenic_adc *adc,
@@ -124,6 +122,8 @@ static int ingenic_adc_write_raw(struct iio_dev *iio_dev,
long m)
{
struct ingenic_adc *adc = iio_priv(iio_dev);
+ struct device *dev = iio_dev->dev.parent;
+ int ret;

switch (m) {
case IIO_CHAN_INFO_SCALE:
@@ -131,6 +131,14 @@ static int ingenic_adc_write_raw(struct iio_dev *iio_dev,
case INGENIC_ADC_BATTERY:
if (!adc->soc_data->battery_vref_mode)
return -EINVAL;
+
+ ret = clk_enable(adc->clk);
+ if (ret) {
+ dev_err(dev, "Failed to enable clock: %d\n",
+ ret);
+ return ret;
+ }
+
if (val > JZ_ADC_BATTERY_LOW_VREF) {
ingenic_adc_set_config(adc,
JZ_ADC_REG_CFG_BAT_MD,
@@ -142,6 +150,9 @@ static int ingenic_adc_write_raw(struct iio_dev *iio_dev,
JZ_ADC_REG_CFG_BAT_MD);
adc->low_vref_mode = true;
}
+
+ clk_disable(adc->clk);
+
return 0;
default:
return -EINVAL;
@@ -312,11 +323,19 @@ static int ingenic_adc_read_avail(struct iio_dev *iio_dev,
};
}

-static int ingenic_adc_read_chan_info_raw(struct ingenic_adc *adc,
+static int ingenic_adc_read_chan_info_raw(struct iio_dev *iio_dev,
struct iio_chan_spec const *chan,
int *val)
{
int bit, ret, engine = (chan->channel == INGENIC_ADC_BATTERY);
+ struct ingenic_adc *adc = iio_priv(iio_dev);
+
+ ret = clk_enable(adc->clk);
+ if (ret) {
+ dev_err(iio_dev->dev.parent, "Failed to enable clock: %d\n",
+ ret);
+ return ret;
+ }

/* We cannot sample AUX/AUX2 in parallel. */
mutex_lock(&adc->aux_lock);
@@ -325,7 +344,6 @@ static int ingenic_adc_read_chan_info_raw(struct ingenic_adc *adc,
ingenic_adc_set_config(adc, JZ_ADC_REG_CFG_AUX_MD, bit);
}

- clk_enable(adc->clk);
ret = ingenic_adc_capture(adc, engine);
if (ret)
goto out;
@@ -342,8 +360,8 @@ static int ingenic_adc_read_chan_info_raw(struct ingenic_adc *adc,

ret = IIO_VAL_INT;
out:
- clk_disable(adc->clk);
mutex_unlock(&adc->aux_lock);
+ clk_disable(adc->clk);

return ret;
}
@@ -358,7 +376,7 @@ static int ingenic_adc_read_raw(struct iio_dev *iio_dev,

switch (m) {
case IIO_CHAN_INFO_RAW:
- return ingenic_adc_read_chan_info_raw(adc, chan, val);
+ return ingenic_adc_read_chan_info_raw(iio_dev, chan, val);
case IIO_CHAN_INFO_SCALE:
switch (chan->channel) {
case INGENIC_ADC_AUX:
--
2.27.0


2020-07-19 20:55:40

by Artur Rojek

[permalink] [raw]
Subject: [PATCH v9 4/5] dt-bindings: iio/adc: Add touchscreen idx for JZ47xx SoC ADC

Introduce support for touchscreen channels found in JZ47xx SoCs.

Signed-off-by: Artur Rojek <[email protected]>
Tested-by: Paul Cercueil <[email protected]>
Acked-by: Rob Herring <[email protected]>
---

Changes:

v2-v7: no change

v8: add XN/YN and XD/YD channels

v9: no change

include/dt-bindings/iio/adc/ingenic,adc.h | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/include/dt-bindings/iio/adc/ingenic,adc.h b/include/dt-bindings/iio/adc/ingenic,adc.h
index 42f871ab3272..4627a00e369e 100644
--- a/include/dt-bindings/iio/adc/ingenic,adc.h
+++ b/include/dt-bindings/iio/adc/ingenic,adc.h
@@ -7,5 +7,11 @@
#define INGENIC_ADC_AUX 0
#define INGENIC_ADC_BATTERY 1
#define INGENIC_ADC_AUX2 2
+#define INGENIC_ADC_TOUCH_XP 3
+#define INGENIC_ADC_TOUCH_YP 4
+#define INGENIC_ADC_TOUCH_XN 5
+#define INGENIC_ADC_TOUCH_YN 6
+#define INGENIC_ADC_TOUCH_XD 7
+#define INGENIC_ADC_TOUCH_YD 8

#endif
--
2.27.0

2020-07-19 20:57:51

by Artur Rojek

[permalink] [raw]
Subject: [PATCH v9 5/5] IIO: Ingenic JZ47xx: Add touchscreen mode.

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 <[email protected]>
Signed-off-by: Paul Cercueil <[email protected]>
Signed-off-by: Artur Rojek <[email protected]>
---

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;
--
2.27.0

2020-07-20 09:53:19

by Jonathan Cameron

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

On Sun, 19 Jul 2020 22:53:07 +0200
Artur Rojek <[email protected]> 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 <[email protected]>
> Signed-off-by: Paul Cercueil <[email protected]>
> Signed-off-by: Artur Rojek <[email protected]>

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;