summaryrefslogtreecommitdiffstats
path: root/drivers/input/touchscreen/sun4i-ts.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-30 09:22:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-30 09:22:00 -0700
commit034dd340b08be1f2f0477ad16131d609f9dbd53c (patch)
tree2536f4b2d7893ccd916b5abdf3c454ad6edc03c2 /drivers/input/touchscreen/sun4i-ts.c
downloadlinux-stable-034dd340b08be1f2f0477ad16131d609f9dbd53c.tar.gz
linux-stable-034dd340b08be1f2f0477ad16131d609f9dbd53c.zip
Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted
Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure
Diffstat (limited to 'drivers/input/touchscreen/sun4i-ts.c')
-rw-r--r--drivers/input/touchscreen/sun4i-ts.c411
1 files changed, 411 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/sun4i-ts.c b/drivers/input/touchscreen/sun4i-ts.c
new file mode 100644
index 000000000..e82860600
--- /dev/null
+++ b/drivers/input/touchscreen/sun4i-ts.c
@@ -0,0 +1,411 @@
+// 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 void 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);
+}
+
+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");