4 files changed, 244 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/input/touchscreen/ts4800-ts.txt b/Documentation/devicetree/bindings/input/touchscreen/ts4800-ts.txt
new file mode 100644
index 000000000000..4c1c092c276b
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/ts4800-ts.txt
@@ -0,0 +1,11 @@
+* TS-4800 Touchscreen bindings
+
+Required properties:
+- compatible: must be "technologic,ts4800-ts"
+- reg: physical base address of the controller and length of memory mapped
+  region.
+- syscon: phandle / integers array that points to the syscon node which
+          describes the FPGA's syscon registers.
+          - phandle to FPGA's syscon
+          - offset to the touchscreen register
+          - offset to the touchscreen enable bit
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 9bcb718668b2..f986e8b44b5f 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -937,6 +937,22 @@ 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
+        select INPUT_POLLDEV
+        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 001357c3f73f..968ff12e3132 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -69,6 +69,7 @@ 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-$(CONFIG_TOUCHSCREEN_TSC200X_CORE)  += tsc200x-core.o
 obj-$(CONFIG_TOUCHSCREEN_TSC2004)       += tsc2004.o
diff --git a/drivers/input/touchscreen/ts4800-ts.c b/drivers/input/touchscreen/ts4800-ts.c
new file mode 100644
index 000000000000..3c3dd78303be
--- /dev/null
+++ b/drivers/input/touchscreen/ts4800-ts.c
@@ -0,0 +1,216 @@
+/*
+ * 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/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
+
+#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_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;
+
+        ts->pendown = false;
+        ts->debounce = DEBOUNCE_COUNT;
+
+        ret = regmap_update_bits(ts->regmap, ts->reg, ts->bit, 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, 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) {
+                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;
+        }
+
+        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);
+
+        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 ts4800_ts *ts;
+        struct resource *res;
+        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;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        ts->base = devm_ioremap_resource(&pdev->dev, res);
+        if (IS_ERR(ts->base))
+                return PTR_ERR(ts->base);
+
+        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;
+
+        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;
+
+        poll_dev->input->name = "TS-4800 Touchscreen";
+        poll_dev->input->phys = ts->phys;
+
+        input_set_capability(poll_dev->input, EV_KEY, BTN_TOUCH);
+        input_set_abs_params(poll_dev->input, ABS_X, 0, MAX_12BIT, 0, 0);
+        input_set_abs_params(poll_dev->input, ABS_Y, 0, MAX_12BIT, 0, 0);
+
+        error = input_register_polled_device(poll_dev);
+        if (error) {
+                dev_err(&pdev->dev,
+                        "Unabled to register polled 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");