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path: root/drivers/input/touchscreen/ts4800-ts.c
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Diffstat (limited to 'drivers/input/touchscreen/ts4800-ts.c')
-rw-r--r--drivers/input/touchscreen/ts4800-ts.c223
1 files changed, 223 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/ts4800-ts.c b/drivers/input/touchscreen/ts4800-ts.c
new file mode 100644
index 000000000..6cf66aadc
--- /dev/null
+++ b/drivers/input/touchscreen/ts4800-ts.c
@@ -0,0 +1,223 @@
+/*
+ * 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/bitops.h>
+#include <linux/input.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
+
+#define DEBOUNCE_COUNT 1
+
+/* 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_dev *input;
+ struct device *dev;
+ char phys[32];
+
+ void __iomem *base;
+ struct regmap *regmap;
+ unsigned int reg;
+ unsigned int bit;
+
+ bool pendown;
+ int debounce;
+};
+
+static int ts4800_ts_open(struct input_dev *input_dev)
+{
+ struct ts4800_ts *ts = input_get_drvdata(input_dev);
+ int error;
+
+ ts->pendown = false;
+ ts->debounce = DEBOUNCE_COUNT;
+
+ error = regmap_update_bits(ts->regmap, ts->reg, ts->bit, ts->bit);
+ if (error) {
+ dev_warn(ts->dev, "Failed to enable touchscreen: %d\n", error);
+ return error;
+ }
+
+ return 0;
+}
+
+static void ts4800_ts_close(struct input_dev *input_dev)
+{
+ struct ts4800_ts *ts = input_get_drvdata(input_dev);
+ int ret;
+
+ ret = regmap_update_bits(ts->regmap, ts->reg, ts->bit, 0);
+ if (ret)
+ dev_warn(ts->dev, "Failed to disable touchscreen\n");
+
+}
+
+static void ts4800_ts_poll(struct input_dev *input_dev)
+{
+ struct ts4800_ts *ts = input_get_drvdata(input_dev);
+ u16 last_x = readw(ts->base + X_OFFSET);
+ u16 last_y = readw(ts->base + Y_OFFSET);
+ bool pendown = last_x & PENDOWN_MASK;
+
+ if (pendown) {
+ if (ts->debounce) {
+ ts->debounce--;
+ 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);
+ } else if (ts->pendown) {
+ ts->pendown = false;
+ ts->debounce = DEBOUNCE_COUNT;
+ input_report_key(input_dev, BTN_TOUCH, 0);
+ input_sync(input_dev);
+ }
+}
+
+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;
+ u32 reg, bit;
+ int error;
+
+ syscon_np = of_parse_phandle(np, "syscon", 0);
+ if (!syscon_np) {
+ dev_err(dev, "no syscon property\n");
+ return -ENODEV;
+ }
+
+ ts->regmap = syscon_node_to_regmap(syscon_np);
+ of_node_put(syscon_np);
+ if (IS_ERR(ts->regmap)) {
+ dev_err(dev, "cannot get parent's regmap\n");
+ return PTR_ERR(ts->regmap);
+ }
+
+ error = of_property_read_u32_index(np, "syscon", 1, &reg);
+ if (error < 0) {
+ dev_err(dev, "no offset in syscon\n");
+ return error;
+ }
+
+ ts->reg = reg;
+
+ error = of_property_read_u32_index(np, "syscon", 2, &bit);
+ if (error < 0) {
+ dev_err(dev, "no bit in syscon\n");
+ return error;
+ }
+
+ ts->bit = BIT(bit);
+
+ return 0;
+}
+
+static int ts4800_ts_probe(struct platform_device *pdev)
+{
+ struct input_dev *input_dev;
+ struct ts4800_ts *ts;
+ int error;
+
+ ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ error = ts4800_parse_dt(pdev, ts);
+ if (error)
+ return error;
+
+ ts->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(ts->base))
+ return PTR_ERR(ts->base);
+
+ input_dev = devm_input_allocate_device(&pdev->dev);
+ if (!input_dev)
+ return -ENOMEM;
+
+ snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&pdev->dev));
+ ts->input = input_dev;
+ ts->dev = &pdev->dev;
+
+ input_set_drvdata(input_dev, ts);
+
+ input_dev->name = "TS-4800 Touchscreen";
+ input_dev->phys = ts->phys;
+
+ input_dev->open = ts4800_ts_open;
+ input_dev->close = ts4800_ts_close;
+
+ input_set_capability(input_dev, EV_KEY, 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);
+
+ error = input_setup_polling(input_dev, ts4800_ts_poll);
+ if (error) {
+ dev_err(&pdev->dev, "Unable to set up polling: %d\n", error);
+ return error;
+ }
+
+ input_set_poll_interval(input_dev, POLL_INTERVAL);
+
+ error = input_register_device(input_dev);
+ if (error) {
+ dev_err(&pdev->dev,
+ "Unable to register input device: %d\n", error);
+ return error;
+ }
+
+ 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,
+};
+module_platform_driver(ts4800_ts_driver);
+
+MODULE_AUTHOR("Damien Riegel <damien.riegel@savoirfairelinux.com>");
+MODULE_DESCRIPTION("TS-4800 Touchscreen Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:ts4800_ts");