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223 lines
5.1 KiB
223 lines
5.1 KiB
/* |
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* Touchscreen driver for the TS-4800 board |
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* |
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* Copyright (c) 2015 - Savoir-faire Linux |
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* |
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* This file is licensed under the terms of the GNU General Public |
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* License version 2. This program is licensed "as is" without any |
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* warranty of any kind, whether express or implied. |
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*/ |
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#include <linux/bitops.h> |
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#include <linux/input.h> |
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#include <linux/io.h> |
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#include <linux/kernel.h> |
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#include <linux/mfd/syscon.h> |
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#include <linux/module.h> |
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#include <linux/of.h> |
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#include <linux/platform_device.h> |
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#include <linux/regmap.h> |
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/* polling interval in ms */ |
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#define POLL_INTERVAL 3 |
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#define DEBOUNCE_COUNT 1 |
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/* sensor values are 12-bit wide */ |
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#define MAX_12BIT ((1 << 12) - 1) |
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#define PENDOWN_MASK 0x1 |
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#define X_OFFSET 0x0 |
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#define Y_OFFSET 0x2 |
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struct ts4800_ts { |
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struct input_dev *input; |
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struct device *dev; |
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char phys[32]; |
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void __iomem *base; |
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struct regmap *regmap; |
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unsigned int reg; |
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unsigned int bit; |
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bool pendown; |
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int debounce; |
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}; |
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static int ts4800_ts_open(struct input_dev *input_dev) |
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{ |
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struct ts4800_ts *ts = input_get_drvdata(input_dev); |
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int error; |
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ts->pendown = false; |
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ts->debounce = DEBOUNCE_COUNT; |
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error = regmap_update_bits(ts->regmap, ts->reg, ts->bit, ts->bit); |
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if (error) { |
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dev_warn(ts->dev, "Failed to enable touchscreen: %d\n", error); |
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return error; |
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} |
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return 0; |
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} |
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static void ts4800_ts_close(struct input_dev *input_dev) |
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{ |
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struct ts4800_ts *ts = input_get_drvdata(input_dev); |
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int ret; |
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ret = regmap_update_bits(ts->regmap, ts->reg, ts->bit, 0); |
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if (ret) |
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dev_warn(ts->dev, "Failed to disable touchscreen\n"); |
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} |
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static void ts4800_ts_poll(struct input_dev *input_dev) |
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{ |
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struct ts4800_ts *ts = input_get_drvdata(input_dev); |
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u16 last_x = readw(ts->base + X_OFFSET); |
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u16 last_y = readw(ts->base + Y_OFFSET); |
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bool pendown = last_x & PENDOWN_MASK; |
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if (pendown) { |
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if (ts->debounce) { |
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ts->debounce--; |
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return; |
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} |
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if (!ts->pendown) { |
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input_report_key(input_dev, BTN_TOUCH, 1); |
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ts->pendown = true; |
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} |
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last_x = ((~last_x) >> 4) & MAX_12BIT; |
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last_y = ((~last_y) >> 4) & MAX_12BIT; |
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input_report_abs(input_dev, ABS_X, last_x); |
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input_report_abs(input_dev, ABS_Y, last_y); |
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input_sync(input_dev); |
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} else if (ts->pendown) { |
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ts->pendown = false; |
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ts->debounce = DEBOUNCE_COUNT; |
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input_report_key(input_dev, BTN_TOUCH, 0); |
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input_sync(input_dev); |
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} |
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} |
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static int ts4800_parse_dt(struct platform_device *pdev, |
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struct ts4800_ts *ts) |
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{ |
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struct device *dev = &pdev->dev; |
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struct device_node *np = dev->of_node; |
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struct device_node *syscon_np; |
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u32 reg, bit; |
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int error; |
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syscon_np = of_parse_phandle(np, "syscon", 0); |
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if (!syscon_np) { |
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dev_err(dev, "no syscon property\n"); |
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return -ENODEV; |
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} |
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ts->regmap = syscon_node_to_regmap(syscon_np); |
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of_node_put(syscon_np); |
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if (IS_ERR(ts->regmap)) { |
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dev_err(dev, "cannot get parent's regmap\n"); |
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return PTR_ERR(ts->regmap); |
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} |
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error = of_property_read_u32_index(np, "syscon", 1, ®); |
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if (error < 0) { |
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dev_err(dev, "no offset in syscon\n"); |
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return error; |
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} |
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ts->reg = reg; |
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error = of_property_read_u32_index(np, "syscon", 2, &bit); |
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if (error < 0) { |
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dev_err(dev, "no bit in syscon\n"); |
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return error; |
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} |
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ts->bit = BIT(bit); |
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return 0; |
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} |
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static int ts4800_ts_probe(struct platform_device *pdev) |
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{ |
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struct input_dev *input_dev; |
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struct ts4800_ts *ts; |
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int error; |
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ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL); |
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if (!ts) |
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return -ENOMEM; |
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error = ts4800_parse_dt(pdev, ts); |
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if (error) |
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return error; |
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ts->base = devm_platform_ioremap_resource(pdev, 0); |
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if (IS_ERR(ts->base)) |
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return PTR_ERR(ts->base); |
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input_dev = devm_input_allocate_device(&pdev->dev); |
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if (!input_dev) |
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return -ENOMEM; |
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snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&pdev->dev)); |
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ts->input = input_dev; |
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ts->dev = &pdev->dev; |
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input_set_drvdata(input_dev, ts); |
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input_dev->name = "TS-4800 Touchscreen"; |
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input_dev->phys = ts->phys; |
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input_dev->open = ts4800_ts_open; |
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input_dev->close = ts4800_ts_close; |
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input_set_capability(input_dev, EV_KEY, BTN_TOUCH); |
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input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0); |
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input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0); |
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error = input_setup_polling(input_dev, ts4800_ts_poll); |
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if (error) { |
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dev_err(&pdev->dev, "Unable to set up polling: %d\n", error); |
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return error; |
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} |
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input_set_poll_interval(input_dev, POLL_INTERVAL); |
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error = input_register_device(input_dev); |
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if (error) { |
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dev_err(&pdev->dev, |
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"Unable to register input device: %d\n", error); |
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return error; |
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} |
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return 0; |
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} |
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static const struct of_device_id ts4800_ts_of_match[] = { |
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{ .compatible = "technologic,ts4800-ts", }, |
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{ }, |
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}; |
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MODULE_DEVICE_TABLE(of, ts4800_ts_of_match); |
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static struct platform_driver ts4800_ts_driver = { |
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.driver = { |
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.name = "ts4800-ts", |
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.of_match_table = ts4800_ts_of_match, |
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}, |
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.probe = ts4800_ts_probe, |
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}; |
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module_platform_driver(ts4800_ts_driver); |
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MODULE_AUTHOR("Damien Riegel <[email protected]>"); |
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MODULE_DESCRIPTION("TS-4800 Touchscreen Driver"); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_ALIAS("platform:ts4800_ts");
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