Merge tag 'staging-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging and IIO updates from Greg KH:
 "Here are the big staging/iio patches for 4.19-rc1.

  Lots of churn here, with tons of cleanups happening in staging
  drivers, a removal of an old crypto driver that no one was using
  (skein), and the addition of some new IIO drivers. Also added was a
  "gasket" driver from Google that needs loads of work and the erofs
  filesystem.

  Even with adding all of the new drivers and a new filesystem, we are
  only adding about 1000 lines overall to the kernel linecount, which
  shows just how much cleanup happened, and how big the unused crypto
  driver was.

  All of these have been in the linux-next tree for a while now with no
  reported issues"

* tag 'staging-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (903 commits)
  staging:rtl8192u: Remove unused macro definitions - Style
  staging:rtl8192u: Add spaces around '+' operator - Style
  staging:rtl8192u: Remove stale comment - Style
  staging: rtl8188eu: remove unused mp_custom_oid.h
  staging: fbtft: Add spaces around / - Style
  staging: fbtft: Erases some repetitive usage of function name - Style
  staging: fbtft: Adjust some empty-line problems - Style
  staging: fbtft: Removes one nesting level to help readability - Style
  staging: fbtft: Changes gamma table to define.
  staging: fbtft: A bit more information on dev_err.
  staging: fbtft: Fixes some alignment issues - Style
  staging: fbtft: Puts macro arguments in parenthesis to avoid precedence issues - Style
  staging: rtl8188eu: remove unused array dB_Invert_Table
  staging: rtl8188eu: remove whitespace, add missing blank line
  staging: rtl8188eu: use is_multicast_ether_addr in rtw_sta_mgt.c
  staging: rtl8188eu: remove whitespace - style
  staging: rtl8188eu: cleanup block comment - style
  staging: rtl8188eu: use is_multicast_ether_addr in rtl8188eu_xmit.c
  staging: rtl8188eu: use is_multicast_ether_addr in recv_linux.c
  staging: rtlwifi: refactor rtl_get_tcb_desc
  ...

3 files changed, 218 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 32267c1afebc..66d1a220726a 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -92,6 +92,19 @@ config TOUCHSCREEN_AD7879_SPI
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad7879-spi.
 
+config TOUCHSCREEN_ADC
+	tristate "Generic ADC based resistive touchscreen"
+	depends on IIO
+	select IIO_BUFFER_CB
+	help
+	  Say Y here if you want to use the generic ADC
+	  resistive touchscreen driver.
+
+	  If unsure, say N (but it's safe to say "Y").
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called resistive-adc-touch.ko.
+
 config TOUCHSCREEN_AR1021_I2C
 	tristate "Microchip AR1020/1021 i2c touchscreen"
 	depends on I2C && OF
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index fd4fd32fb73f..35bd0619edf1 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_TOUCHSCREEN_AD7877)	+= ad7877.o
 obj-$(CONFIG_TOUCHSCREEN_AD7879)	+= ad7879.o
 obj-$(CONFIG_TOUCHSCREEN_AD7879_I2C)	+= ad7879-i2c.o
 obj-$(CONFIG_TOUCHSCREEN_AD7879_SPI)	+= ad7879-spi.o
+obj-$(CONFIG_TOUCHSCREEN_ADC)		+= resistive-adc-touch.o
 obj-$(CONFIG_TOUCHSCREEN_ADS7846)	+= ads7846.o
 obj-$(CONFIG_TOUCHSCREEN_AR1021_I2C)	+= ar1021_i2c.o
 obj-$(CONFIG_TOUCHSCREEN_ATMEL_MXT)	+= atmel_mxt_ts.o
diff --git a/drivers/input/touchscreen/resistive-adc-touch.c b/drivers/input/touchscreen/resistive-adc-touch.c
new file mode 100644
index 000000000000..cfc8bb4553f7
--- /dev/null
+++ b/drivers/input/touchscreen/resistive-adc-touch.c
@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ADC generic resistive touchscreen (GRTS)
+ * This is a generic input driver that connects to an ADC
+ * given the channels in device tree, and reports events to the input
+ * subsystem.
+ *
+ * Copyright (C) 2017,2018 Microchip Technology,
+ * Author: Eugen Hristev <eugen.hristev@microchip.com>
+ *
+ */
+#include <linux/input.h>
+#include <linux/input/touchscreen.h>
+#include <linux/iio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+
+#define DRIVER_NAME					"resistive-adc-touch"
+#define GRTS_DEFAULT_PRESSURE_MIN			50000
+#define GRTS_MAX_POS_MASK				GENMASK(11, 0)
+
+/**
+ * grts_state - generic resistive touch screen information struct
+ * @pressure_min:	number representing the minimum for the pressure
+ * @pressure:		are we getting pressure info or not
+ * @iio_chans:		list of channels acquired
+ * @iio_cb:		iio_callback buffer for the data
+ * @input:		the input device structure that we register
+ * @prop:		touchscreen properties struct
+ */
+struct grts_state {
+	u32				pressure_min;
+	bool				pressure;
+	struct iio_channel		*iio_chans;
+	struct iio_cb_buffer		*iio_cb;
+	struct input_dev		*input;
+	struct touchscreen_properties	prop;
+};
+
+static int grts_cb(const void *data, void *private)
+{
+	const u16 *touch_info = data;
+	struct grts_state *st = private;
+	unsigned int x, y, press = 0x0;
+
+	/* channel data coming in buffer in the order below */
+	x = touch_info[0];
+	y = touch_info[1];
+	if (st->pressure)
+		press = touch_info[2];
+
+	if ((!x && !y) || (st->pressure && (press < st->pressure_min))) {
+		/* report end of touch */
+		input_report_key(st->input, BTN_TOUCH, 0);
+		input_sync(st->input);
+		return 0;
+	}
+
+	/* report proper touch to subsystem*/
+	touchscreen_report_pos(st->input, &st->prop, x, y, false);
+	if (st->pressure)
+		input_report_abs(st->input, ABS_PRESSURE, press);
+	input_report_key(st->input, BTN_TOUCH, 1);
+	input_sync(st->input);
+
+	return 0;
+}
+
+static int grts_open(struct input_dev *dev)
+{
+	int error;
+	struct grts_state *st = input_get_drvdata(dev);
+
+	error = iio_channel_start_all_cb(st->iio_cb);
+	if (error) {
+		dev_err(dev->dev.parent, "failed to start callback buffer.\n");
+		return error;
+	}
+	return 0;
+}
+
+static void grts_close(struct input_dev *dev)
+{
+	struct grts_state *st = input_get_drvdata(dev);
+
+	iio_channel_stop_all_cb(st->iio_cb);
+}
+
+static void grts_disable(void *data)
+{
+	iio_channel_release_all_cb(data);
+}
+
+static int grts_probe(struct platform_device *pdev)
+{
+	struct grts_state *st;
+	struct input_dev *input;
+	struct device *dev = &pdev->dev;
+	struct iio_channel *chan;
+	int error;
+
+	st = devm_kzalloc(dev, sizeof(struct grts_state), GFP_KERNEL);
+	if (!st)
+		return -ENOMEM;
+
+	/* get the channels from IIO device */
+	st->iio_chans = devm_iio_channel_get_all(dev);
+	if (IS_ERR(st->iio_chans)) {
+		error = PTR_ERR(st->iio_chans);
+		if (error != -EPROBE_DEFER)
+			dev_err(dev, "can't get iio channels.\n");
+		return error;
+	}
+
+	chan = &st->iio_chans[0];
+	st->pressure = false;
+	while (chan && chan->indio_dev) {
+		if (!strcmp(chan->channel->datasheet_name, "pressure"))
+			st->pressure = true;
+		chan++;
+	}
+
+	if (st->pressure) {
+		error = device_property_read_u32(dev,
+						 "touchscreen-min-pressure",
+						 &st->pressure_min);
+		if (error) {
+			dev_dbg(dev, "can't get touchscreen-min-pressure property.\n");
+			st->pressure_min = GRTS_DEFAULT_PRESSURE_MIN;
+		}
+	}
+
+	input = devm_input_allocate_device(dev);
+	if (!input) {
+		dev_err(dev, "failed to allocate input device.\n");
+		return -ENOMEM;
+	}
+
+	input->name = DRIVER_NAME;
+	input->id.bustype = BUS_HOST;
+	input->open = grts_open;
+	input->close = grts_close;
+
+	input_set_abs_params(input, ABS_X, 0, GRTS_MAX_POS_MASK - 1, 0, 0);
+	input_set_abs_params(input, ABS_Y, 0, GRTS_MAX_POS_MASK - 1, 0, 0);
+	if (st->pressure)
+		input_set_abs_params(input, ABS_PRESSURE, st->pressure_min,
+				     0xffff, 0, 0);
+
+	input_set_capability(input, EV_KEY, BTN_TOUCH);
+
+	/* parse optional device tree properties */
+	touchscreen_parse_properties(input, false, &st->prop);
+
+	st->input = input;
+	input_set_drvdata(input, st);
+
+	error = input_register_device(input);
+	if (error) {
+		dev_err(dev, "failed to register input device.");
+		return error;
+	}
+
+	st->iio_cb = iio_channel_get_all_cb(dev, grts_cb, st);
+	if (IS_ERR(st->iio_cb)) {
+		dev_err(dev, "failed to allocate callback buffer.\n");
+		return PTR_ERR(st->iio_cb);
+	}
+
+	error = devm_add_action_or_reset(dev, grts_disable, st->iio_cb);
+	if (error) {
+		dev_err(dev, "failed to add disable action.\n");
+		return error;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id grts_of_match[] = {
+	{
+		.compatible = "resistive-adc-touch",
+	}, {
+		/* sentinel */
+	},
+};
+
+MODULE_DEVICE_TABLE(of, grts_of_match);
+
+static struct platform_driver grts_driver = {
+	.probe = grts_probe,
+	.driver = {
+		.name = DRIVER_NAME,
+		.of_match_table = of_match_ptr(grts_of_match),
+	},
+};
+
+module_platform_driver(grts_driver);
+
+MODULE_AUTHOR("Eugen Hristev <eugen.hristev@microchip.com>");
+MODULE_DESCRIPTION("Generic ADC Resistive Touch Driver");
+MODULE_LICENSE("GPL v2");