1 files changed, 413 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/sun4i-ts.c b/drivers/input/touchscreen/sun4i-ts.c
new file mode 100644
index 0000000000..bb3c6072fc
--- /dev/null
+++ b/drivers/input/touchscreen/sun4i-ts.c
@@ -0,0 +1,413 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Allwinner sunxi resistive touchscreen controller driver
+ *
+ * Copyright (C) 2013 - 2014 Hans de Goede <hdegoede@redhat.com>
+ *
+ * The hwmon parts are based on work by Corentin LABBE which is:
+ * Copyright (C) 2013 Corentin LABBE <clabbe.montjoie@gmail.com>
+ */
+
+/*
+ * The sun4i-ts controller is capable of detecting a second touch, but when a
+ * second touch is present then the accuracy becomes so bad the reported touch
+ * location is not useable.
+ *
+ * The original android driver contains some complicated heuristics using the
+ * aprox. distance between the 2 touches to see if the user is making a pinch
+ * open / close movement, and then reports emulated multi-touch events around
+ * the last touch coordinate (as the dual-touch coordinates are worthless).
+ *
+ * These kinds of heuristics are just asking for trouble (and don't belong
+ * in the kernel). So this driver offers straight forward, reliable single
+ * touch functionality only.
+ *
+ * s.a. A20 User Manual "1.15 TP" (Documentation/arch/arm/sunxi.rst)
+ * (looks like the description in the A20 User Manual v1.3 is better
+ * than the one in the A10 User Manual v.1.5)
+ */
+
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/thermal.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define TP_CTRL0		0x00
+#define TP_CTRL1		0x04
+#define TP_CTRL2		0x08
+#define TP_CTRL3		0x0c
+#define TP_INT_FIFOC		0x10
+#define TP_INT_FIFOS		0x14
+#define TP_TPR			0x18
+#define TP_CDAT			0x1c
+#define TEMP_DATA		0x20
+#define TP_DATA			0x24
+
+/* TP_CTRL0 bits */
+#define ADC_FIRST_DLY(x)	((x) << 24) /* 8 bits */
+#define ADC_FIRST_DLY_MODE(x)	((x) << 23)
+#define ADC_CLK_SEL(x)		((x) << 22)
+#define ADC_CLK_DIV(x)		((x) << 20) /* 3 bits */
+#define FS_DIV(x)		((x) << 16) /* 4 bits */
+#define T_ACQ(x)		((x) << 0) /* 16 bits */
+
+/* TP_CTRL1 bits */
+#define STYLUS_UP_DEBOUN(x)	((x) << 12) /* 8 bits */
+#define STYLUS_UP_DEBOUN_EN(x)	((x) << 9)
+#define TOUCH_PAN_CALI_EN(x)	((x) << 6)
+#define TP_DUAL_EN(x)		((x) << 5)
+#define TP_MODE_EN(x)		((x) << 4)
+#define TP_ADC_SELECT(x)	((x) << 3)
+#define ADC_CHAN_SELECT(x)	((x) << 0)  /* 3 bits */
+
+/* on sun6i, bits 3~6 are left shifted by 1 to 4~7 */
+#define SUN6I_TP_MODE_EN(x)	((x) << 5)
+
+/* TP_CTRL2 bits */
+#define TP_SENSITIVE_ADJUST(x)	((x) << 28) /* 4 bits */
+#define TP_MODE_SELECT(x)	((x) << 26) /* 2 bits */
+#define PRE_MEA_EN(x)		((x) << 24)
+#define PRE_MEA_THRE_CNT(x)	((x) << 0) /* 24 bits */
+
+/* TP_CTRL3 bits */
+#define FILTER_EN(x)		((x) << 2)
+#define FILTER_TYPE(x)		((x) << 0)  /* 2 bits */
+
+/* TP_INT_FIFOC irq and fifo mask / control bits */
+#define TEMP_IRQ_EN(x)		((x) << 18)
+#define OVERRUN_IRQ_EN(x)	((x) << 17)
+#define DATA_IRQ_EN(x)		((x) << 16)
+#define TP_DATA_XY_CHANGE(x)	((x) << 13)
+#define FIFO_TRIG(x)		((x) << 8)  /* 5 bits */
+#define DATA_DRQ_EN(x)		((x) << 7)
+#define FIFO_FLUSH(x)		((x) << 4)
+#define TP_UP_IRQ_EN(x)		((x) << 1)
+#define TP_DOWN_IRQ_EN(x)	((x) << 0)
+
+/* TP_INT_FIFOS irq and fifo status bits */
+#define TEMP_DATA_PENDING	BIT(18)
+#define FIFO_OVERRUN_PENDING	BIT(17)
+#define FIFO_DATA_PENDING	BIT(16)
+#define TP_IDLE_FLG		BIT(2)
+#define TP_UP_PENDING		BIT(1)
+#define TP_DOWN_PENDING		BIT(0)
+
+/* TP_TPR bits */
+#define TEMP_ENABLE(x)		((x) << 16)
+#define TEMP_PERIOD(x)		((x) << 0)  /* t = x * 256 * 16 / clkin */
+
+struct sun4i_ts_data {
+	struct device *dev;
+	struct input_dev *input;
+	void __iomem *base;
+	unsigned int irq;
+	bool ignore_fifo_data;
+	int temp_data;
+	int temp_offset;
+	int temp_step;
+};
+
+static void sun4i_ts_irq_handle_input(struct sun4i_ts_data *ts, u32 reg_val)
+{
+	u32 x, y;
+
+	if (reg_val & FIFO_DATA_PENDING) {
+		x = readl(ts->base + TP_DATA);
+		y = readl(ts->base + TP_DATA);
+		/* The 1st location reported after an up event is unreliable */
+		if (!ts->ignore_fifo_data) {
+			input_report_abs(ts->input, ABS_X, x);
+			input_report_abs(ts->input, ABS_Y, y);
+			/*
+			 * The hardware has a separate down status bit, but
+			 * that gets set before we get the first location,
+			 * resulting in reporting a click on the old location.
+			 */
+			input_report_key(ts->input, BTN_TOUCH, 1);
+			input_sync(ts->input);
+		} else {
+			ts->ignore_fifo_data = false;
+		}
+	}
+
+	if (reg_val & TP_UP_PENDING) {
+		ts->ignore_fifo_data = true;
+		input_report_key(ts->input, BTN_TOUCH, 0);
+		input_sync(ts->input);
+	}
+}
+
+static irqreturn_t sun4i_ts_irq(int irq, void *dev_id)
+{
+	struct sun4i_ts_data *ts = dev_id;
+	u32 reg_val;
+
+	reg_val  = readl(ts->base + TP_INT_FIFOS);
+
+	if (reg_val & TEMP_DATA_PENDING)
+		ts->temp_data = readl(ts->base + TEMP_DATA);
+
+	if (ts->input)
+		sun4i_ts_irq_handle_input(ts, reg_val);
+
+	writel(reg_val, ts->base + TP_INT_FIFOS);
+
+	return IRQ_HANDLED;
+}
+
+static int sun4i_ts_open(struct input_dev *dev)
+{
+	struct sun4i_ts_data *ts = input_get_drvdata(dev);
+
+	/* Flush, set trig level to 1, enable temp, data and up irqs */
+	writel(TEMP_IRQ_EN(1) | DATA_IRQ_EN(1) | FIFO_TRIG(1) | FIFO_FLUSH(1) |
+		TP_UP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
+
+	return 0;
+}
+
+static void sun4i_ts_close(struct input_dev *dev)
+{
+	struct sun4i_ts_data *ts = input_get_drvdata(dev);
+
+	/* Deactivate all input IRQs */
+	writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
+}
+
+static int sun4i_get_temp(const struct sun4i_ts_data *ts, int *temp)
+{
+	/* No temp_data until the first irq */
+	if (ts->temp_data == -1)
+		return -EAGAIN;
+
+	*temp = ts->temp_data * ts->temp_step - ts->temp_offset;
+
+	return 0;
+}
+
+static int sun4i_get_tz_temp(struct thermal_zone_device *tz, int *temp)
+{
+	return sun4i_get_temp(thermal_zone_device_priv(tz), temp);
+}
+
+static const struct thermal_zone_device_ops sun4i_ts_tz_ops = {
+	.get_temp = sun4i_get_tz_temp,
+};
+
+static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
+			 char *buf)
+{
+	struct sun4i_ts_data *ts = dev_get_drvdata(dev);
+	int temp;
+	int error;
+
+	error = sun4i_get_temp(ts, &temp);
+	if (error)
+		return error;
+
+	return sprintf(buf, "%d\n", temp);
+}
+
+static ssize_t show_temp_label(struct device *dev,
+			      struct device_attribute *devattr, char *buf)
+{
+	return sprintf(buf, "SoC temperature\n");
+}
+
+static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
+static DEVICE_ATTR(temp1_label, S_IRUGO, show_temp_label, NULL);
+
+static struct attribute *sun4i_ts_attrs[] = {
+	&dev_attr_temp1_input.attr,
+	&dev_attr_temp1_label.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(sun4i_ts);
+
+static int sun4i_ts_probe(struct platform_device *pdev)
+{
+	struct sun4i_ts_data *ts;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct device *hwmon;
+	struct thermal_zone_device *thermal;
+	int error;
+	u32 reg;
+	bool ts_attached;
+	u32 tp_sensitive_adjust = 15;
+	u32 filter_type = 1;
+
+	ts = devm_kzalloc(dev, sizeof(struct sun4i_ts_data), GFP_KERNEL);
+	if (!ts)
+		return -ENOMEM;
+
+	ts->dev = dev;
+	ts->ignore_fifo_data = true;
+	ts->temp_data = -1;
+	if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts")) {
+		/* Allwinner SDK has temperature (C) = (value / 6) - 271 */
+		ts->temp_offset = 271000;
+		ts->temp_step = 167;
+	} else if (of_device_is_compatible(np, "allwinner,sun4i-a10-ts")) {
+		/*
+		 * The A10 temperature sensor has quite a wide spread, these
+		 * parameters are based on the averaging of the calibration
+		 * results of 4 completely different boards, with a spread of
+		 * temp_step from 0.096 - 0.170 and temp_offset from 176 - 331.
+		 */
+		ts->temp_offset = 257000;
+		ts->temp_step = 133;
+	} else {
+		/*
+		 * The user manuals do not contain the formula for calculating
+		 * the temperature. The formula used here is from the AXP209,
+		 * which is designed by X-Powers, an affiliate of Allwinner:
+		 *
+		 *     temperature (C) = (value * 0.1) - 144.7
+		 *
+		 * Allwinner does not have any documentation whatsoever for
+		 * this hardware. Moreover, it is claimed that the sensor
+		 * is inaccurate and cannot work properly.
+		 */
+		ts->temp_offset = 144700;
+		ts->temp_step = 100;
+	}
+
+	ts_attached = of_property_read_bool(np, "allwinner,ts-attached");
+	if (ts_attached) {
+		ts->input = devm_input_allocate_device(dev);
+		if (!ts->input)
+			return -ENOMEM;
+
+		ts->input->name = pdev->name;
+		ts->input->phys = "sun4i_ts/input0";
+		ts->input->open = sun4i_ts_open;
+		ts->input->close = sun4i_ts_close;
+		ts->input->id.bustype = BUS_HOST;
+		ts->input->id.vendor = 0x0001;
+		ts->input->id.product = 0x0001;
+		ts->input->id.version = 0x0100;
+		ts->input->evbit[0] =  BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS);
+		__set_bit(BTN_TOUCH, ts->input->keybit);
+		input_set_abs_params(ts->input, ABS_X, 0, 4095, 0, 0);
+		input_set_abs_params(ts->input, ABS_Y, 0, 4095, 0, 0);
+		input_set_drvdata(ts->input, ts);
+	}
+
+	ts->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(ts->base))
+		return PTR_ERR(ts->base);
+
+	ts->irq = platform_get_irq(pdev, 0);
+	error = devm_request_irq(dev, ts->irq, sun4i_ts_irq, 0, "sun4i-ts", ts);
+	if (error)
+		return error;
+
+	/*
+	 * Select HOSC clk, clkin = clk / 6, adc samplefreq = clkin / 8192,
+	 * t_acq = clkin / (16 * 64)
+	 */
+	writel(ADC_CLK_SEL(0) | ADC_CLK_DIV(2) | FS_DIV(7) | T_ACQ(63),
+	       ts->base + TP_CTRL0);
+
+	/*
+	 * tp_sensitive_adjust is an optional property
+	 * tp_mode = 0 : only x and y coordinates, as we don't use dual touch
+	 */
+	of_property_read_u32(np, "allwinner,tp-sensitive-adjust",
+			     &tp_sensitive_adjust);
+	writel(TP_SENSITIVE_ADJUST(tp_sensitive_adjust) | TP_MODE_SELECT(0),
+	       ts->base + TP_CTRL2);
+
+	/*
+	 * Enable median and averaging filter, optional property for
+	 * filter type.
+	 */
+	of_property_read_u32(np, "allwinner,filter-type", &filter_type);
+	writel(FILTER_EN(1) | FILTER_TYPE(filter_type), ts->base + TP_CTRL3);
+
+	/* Enable temperature measurement, period 1953 (2 seconds) */
+	writel(TEMP_ENABLE(1) | TEMP_PERIOD(1953), ts->base + TP_TPR);
+
+	/*
+	 * Set stylus up debounce to aprox 10 ms, enable debounce, and
+	 * finally enable tp mode.
+	 */
+	reg = STYLUS_UP_DEBOUN(5) | STYLUS_UP_DEBOUN_EN(1);
+	if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts"))
+		reg |= SUN6I_TP_MODE_EN(1);
+	else
+		reg |= TP_MODE_EN(1);
+	writel(reg, ts->base + TP_CTRL1);
+
+	/*
+	 * The thermal core does not register hwmon devices for DT-based
+	 * thermal zone sensors, such as this one.
+	 */
+	hwmon = devm_hwmon_device_register_with_groups(ts->dev, "sun4i_ts",
+						       ts, sun4i_ts_groups);
+	if (IS_ERR(hwmon))
+		return PTR_ERR(hwmon);
+
+	thermal = devm_thermal_of_zone_register(ts->dev, 0, ts,
+						&sun4i_ts_tz_ops);
+	if (IS_ERR(thermal))
+		return PTR_ERR(thermal);
+
+	writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
+
+	if (ts_attached) {
+		error = input_register_device(ts->input);
+		if (error) {
+			writel(0, ts->base + TP_INT_FIFOC);
+			return error;
+		}
+	}
+
+	platform_set_drvdata(pdev, ts);
+	return 0;
+}
+
+static int sun4i_ts_remove(struct platform_device *pdev)
+{
+	struct sun4i_ts_data *ts = platform_get_drvdata(pdev);
+
+	/* Explicit unregister to avoid open/close changing the imask later */
+	if (ts->input)
+		input_unregister_device(ts->input);
+
+	/* Deactivate all IRQs */
+	writel(0, ts->base + TP_INT_FIFOC);
+
+	return 0;
+}
+
+static const struct of_device_id sun4i_ts_of_match[] = {
+	{ .compatible = "allwinner,sun4i-a10-ts", },
+	{ .compatible = "allwinner,sun5i-a13-ts", },
+	{ .compatible = "allwinner,sun6i-a31-ts", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sun4i_ts_of_match);
+
+static struct platform_driver sun4i_ts_driver = {
+	.driver = {
+		.name	= "sun4i-ts",
+		.of_match_table = sun4i_ts_of_match,
+	},
+	.probe	= sun4i_ts_probe,
+	.remove	= sun4i_ts_remove,
+};
+
+module_platform_driver(sun4i_ts_driver);
+
+MODULE_DESCRIPTION("Allwinner sun4i resistive touchscreen controller driver");
+MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
+MODULE_LICENSE("GPL");