diff options
Diffstat (limited to 'drivers/input/touchscreen/ts4800-ts.c')
| -rw-r--r-- | drivers/input/touchscreen/ts4800-ts.c | 223 |
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, ®); + 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"); |