[PATCH 2/2] Input: add touchscreen support for TS-4800
From: Damien Riegel
Date: Thu Dec 10 2015 - 11:11:32 EST
On this board, the touchscreen, an ads7843, is not handled directly by
Linux but by a companion FPGA. This FPGA is memory-mapped and the IP
design is very similar to the mk712.
This commit adds the support for this IP.
Signed-off-by: Damien Riegel <damien.riegel@xxxxxxxxxxxxxxxxxxxx>
---
drivers/input/touchscreen/Kconfig | 15 +++
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/ts4800-ts.c | 238 ++++++++++++++++++++++++++++++++++
3 files changed, 254 insertions(+)
create mode 100644 drivers/input/touchscreen/ts4800-ts.c
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index deb14c1..2d3b2f2 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -914,6 +914,21 @@ config TOUCHSCREEN_TOUCHIT213
To compile this driver as a module, choose M here: the
module will be called touchit213.
+config TOUCHSCREEN_TS4800
+ tristate "TS-4800 touchscreen"
+ depends on HAS_IOMEM && OF
+ select MFD_SYSCON
+ help
+ Say Y here if you have a touchscreen on a TS-4800 board.
+
+ On TS-4800, the touchscreen is not handled directly by Linux but by
+ a companion FPGA.
+
+ If unsure, say N.
+
+ To compile this driver as a module, choose M here: the
+ module will be called ts4800_ts.
+
config TOUCHSCREEN_TSC_SERIO
tristate "TSC-10/25/40 serial touchscreen support"
select SERIO
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 1b79cc0..5d81ba8c 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -67,6 +67,7 @@ obj-$(CONFIG_TOUCHSCREEN_TI_AM335X_TSC) += ti_am335x_tsc.o
obj-$(CONFIG_TOUCHSCREEN_TOUCHIT213) += touchit213.o
obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT) += touchright.o
obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN) += touchwin.o
+obj-$(CONFIG_TOUCHSCREEN_TS4800) += ts4800-ts.o
obj-$(CONFIG_TOUCHSCREEN_TSC_SERIO) += tsc40.o
obj-$(CONFIG_TOUCHSCREEN_TSC2005) += tsc2005.o
obj-$(CONFIG_TOUCHSCREEN_TSC2007) += tsc2007.o
diff --git a/drivers/input/touchscreen/ts4800-ts.c b/drivers/input/touchscreen/ts4800-ts.c
new file mode 100644
index 0000000..1e81b17
--- /dev/null
+++ b/drivers/input/touchscreen/ts4800-ts.c
@@ -0,0 +1,238 @@
+/*
+ * Touchscreen driver for the TS-4800 board
+ *
+ * Copyright (c) 2015 - Savoir-faire Linux
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/input.h>
+#include <linux/input-polldev.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+/* polling interval in ms*/
+#define POLL_INTERVAL 3
+
+/* sensor values are 12-bit wide */
+#define MAX_12BIT ((1 << 12) - 1)
+
+#define PENDOWN_MASK 0x1
+
+#define X_OFFSET 0x0
+#define Y_OFFSET 0x2
+
+struct ts4800_ts {
+ struct input_polled_dev *poll_dev;
+ struct device *dev;
+ char phys[32];
+
+ void __iomem *base;
+ struct regmap *regmap;
+ unsigned int reg;
+ unsigned int bit;
+
+ bool pendown;
+ int debounce;
+};
+
+static void ts4800_ts_open(struct input_polled_dev *dev)
+{
+ struct ts4800_ts *ts = dev->private;
+ int ret;
+
+ ret = regmap_update_bits(ts->regmap, ts->reg,
+ 1 << ts->bit, 1 << ts->bit);
+ if (ret)
+ dev_warn(ts->dev, "Failed to enable touchscreen\n");
+}
+
+static void ts4800_ts_close(struct input_polled_dev *dev)
+{
+ struct ts4800_ts *ts = dev->private;
+ int ret;
+
+ ret = regmap_update_bits(ts->regmap, ts->reg,
+ 1 << ts->bit, 0);
+ if (ret)
+ dev_warn(ts->dev, "Failed to disable touchscreen\n");
+
+}
+
+static void ts4800_ts_poll(struct input_polled_dev *dev)
+{
+ struct input_dev *input_dev = dev->input;
+ struct ts4800_ts *ts = dev->private;
+ u16 last_x = readw(ts->base + X_OFFSET);
+ u16 last_y = readw(ts->base + Y_OFFSET);
+ bool pendown = last_x & PENDOWN_MASK;
+
+ if (!pendown && ts->pendown) {
+ ts->pendown = false;
+ ts->debounce = 1;
+ input_report_key(input_dev, BTN_TOUCH, 0);
+ input_sync(input_dev);
+ }
+
+ if (pendown) {
+ if (ts->debounce) {
+ ts->debounce = 0;
+ return;
+ }
+
+ if (!ts->pendown) {
+ input_report_key(input_dev, BTN_TOUCH, 1);
+ ts->pendown = true;
+ }
+
+ last_x = ((~last_x) >> 4) & MAX_12BIT;
+ last_y = ((~last_y) >> 4) & MAX_12BIT;
+
+ input_report_abs(input_dev, ABS_X, last_x);
+ input_report_abs(input_dev, ABS_Y, last_y);
+ input_sync(input_dev);
+ }
+}
+
+static void ts4800_input_setup(struct input_dev *input_dev)
+{
+ input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+ input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+
+ input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
+ input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
+}
+
+static int ts4800_parse_dt(struct platform_device *pdev,
+ struct ts4800_ts *ts)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct device_node *syscon_np;
+ struct resource *res;
+ u32 reg, bit;
+ int ret;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ ts->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(ts->base))
+ return PTR_ERR(ts->base);
+
+ syscon_np = of_parse_phandle(np, "syscon", 0);
+ if (!syscon_np) {
+ dev_err(dev, "no syscon property\n");
+ return -ENODEV;
+ }
+
+ ret = of_property_read_u32_index(np, "syscon", 1, ®);
+ if (ret < 0) {
+ dev_err(dev, "no offset in syscon\n");
+ return ret;
+ }
+
+ ret = of_property_read_u32_index(np, "syscon", 2, &bit);
+ if (ret < 0) {
+ dev_err(dev, "no bit in syscon\n");
+ return ret;
+ }
+
+ ts->reg = reg;
+ ts->bit = bit;
+ ts->regmap = syscon_node_to_regmap(syscon_np);
+
+ if (IS_ERR(ts->regmap)) {
+ dev_err(dev, "cannot get parent's regmap\n");
+ return PTR_ERR(ts->regmap);
+ }
+
+ return 0;
+}
+
+static int ts4800_ts_probe(struct platform_device *pdev)
+{
+ struct input_polled_dev *poll_dev;
+ struct input_dev *input_dev;
+ struct ts4800_ts *ts;
+ int ret;
+
+ ts = devm_kzalloc(&pdev->dev, sizeof(struct ts4800_ts), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ ret = ts4800_parse_dt(pdev, ts);
+ if (ret)
+ return ret;
+
+ poll_dev = devm_input_allocate_polled_device(&pdev->dev);
+ if (!poll_dev)
+ return -ENOMEM;
+
+ snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&pdev->dev));
+ ts->poll_dev = poll_dev;
+ ts->dev = &pdev->dev;
+ ts->pendown = false;
+ ts->debounce = 1;
+
+ poll_dev->private = ts;
+ poll_dev->poll_interval = POLL_INTERVAL;
+ poll_dev->open = ts4800_ts_open;
+ poll_dev->close = ts4800_ts_close;
+ poll_dev->poll = ts4800_ts_poll;
+
+ ts4800_input_setup(poll_dev->input);
+
+ input_dev = poll_dev->input;
+ input_dev->name = "TS-4800 Touchscreen";
+ input_dev->phys = ts->phys;
+ input_dev->dev.parent = pdev->dev.parent;
+
+ ret = input_register_polled_device(poll_dev);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "Unabled to register polled input device (%d)\n",
+ ret);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, ts);
+
+ return 0;
+}
+
+static int ts4800_ts_remove(struct platform_device *pdev)
+{
+ struct ts4800_ts *ts = platform_get_drvdata(pdev);
+ struct input_polled_dev *poll_dev = ts->poll_dev;
+
+ input_unregister_polled_device(poll_dev);
+
+ return 0;
+}
+
+static const struct of_device_id ts4800_ts_of_match[] = {
+ { .compatible = "technologic,ts4800-ts", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, ts4800_ts_of_match);
+
+static struct platform_driver ts4800_ts_driver = {
+ .driver = {
+ .name = "ts4800-ts",
+ .of_match_table = ts4800_ts_of_match,
+ },
+ .probe = ts4800_ts_probe,
+ .remove = ts4800_ts_remove,
+};
+module_platform_driver(ts4800_ts_driver);
+
+MODULE_AUTHOR("Damien Riegel <damien.riegel@xxxxxxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("TS-4800 Touchscreen Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:ts4800_ts");
--
2.5.0
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