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![Peter Chen](/assets/img/avatar_default.png)
of_node_put needs to be called when the device node which is got from of_parse_phandle has finished using. Signed-off-by: Peter Chen <peter.chen@nxp.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
217 lines
5 KiB
C
217 lines
5 KiB
C
/*
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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/input-polldev.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_polled_dev *poll_dev;
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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 void ts4800_ts_open(struct input_polled_dev *dev)
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{
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struct ts4800_ts *ts = dev->private;
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int ret;
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ts->pendown = false;
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ts->debounce = DEBOUNCE_COUNT;
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ret = regmap_update_bits(ts->regmap, ts->reg, ts->bit, ts->bit);
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if (ret)
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dev_warn(ts->dev, "Failed to enable touchscreen\n");
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}
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static void ts4800_ts_close(struct input_polled_dev *dev)
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{
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struct ts4800_ts *ts = dev->private;
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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_polled_dev *dev)
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{
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struct input_dev *input_dev = dev->input;
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struct ts4800_ts *ts = dev->private;
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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_polled_dev *poll_dev;
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struct ts4800_ts *ts;
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struct resource *res;
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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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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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ts->base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(ts->base))
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return PTR_ERR(ts->base);
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poll_dev = devm_input_allocate_polled_device(&pdev->dev);
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if (!poll_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->poll_dev = poll_dev;
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ts->dev = &pdev->dev;
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poll_dev->private = ts;
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poll_dev->poll_interval = POLL_INTERVAL;
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poll_dev->open = ts4800_ts_open;
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poll_dev->close = ts4800_ts_close;
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poll_dev->poll = ts4800_ts_poll;
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poll_dev->input->name = "TS-4800 Touchscreen";
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poll_dev->input->phys = ts->phys;
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input_set_capability(poll_dev->input, EV_KEY, BTN_TOUCH);
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input_set_abs_params(poll_dev->input, ABS_X, 0, MAX_12BIT, 0, 0);
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input_set_abs_params(poll_dev->input, ABS_Y, 0, MAX_12BIT, 0, 0);
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error = input_register_polled_device(poll_dev);
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if (error) {
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dev_err(&pdev->dev,
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"Unabled to register polled input device (%d)\n",
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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 <damien.riegel@savoirfairelinux.com>");
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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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