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-rw-r--r--drivers/input/touchscreen/stmpe-ts.c379
1 files changed, 379 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/stmpe-ts.c b/drivers/input/touchscreen/stmpe-ts.c
new file mode 100644
index 000000000..25c45c3a3
--- /dev/null
+++ b/drivers/input/touchscreen/stmpe-ts.c
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * STMicroelectronics STMPE811 Touchscreen Driver
+ *
+ * (C) 2010 Luotao Fu <l.fu@pengutronix.de>
+ * All rights reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/input.h>
+#include <linux/input/touchscreen.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/workqueue.h>
+
+#include <linux/mfd/stmpe.h>
+
+/* Register layouts and functionalities are identical on all stmpexxx variants
+ * with touchscreen controller
+ */
+#define STMPE_REG_INT_STA 0x0B
+#define STMPE_REG_TSC_CTRL 0x40
+#define STMPE_REG_TSC_CFG 0x41
+#define STMPE_REG_FIFO_TH 0x4A
+#define STMPE_REG_FIFO_STA 0x4B
+#define STMPE_REG_FIFO_SIZE 0x4C
+#define STMPE_REG_TSC_DATA_XYZ 0x52
+#define STMPE_REG_TSC_FRACTION_Z 0x56
+#define STMPE_REG_TSC_I_DRIVE 0x58
+
+#define OP_MOD_XYZ 0
+
+#define STMPE_TSC_CTRL_TSC_EN (1<<0)
+
+#define STMPE_FIFO_STA_RESET (1<<0)
+
+#define STMPE_IRQ_TOUCH_DET 0
+
+#define STMPE_TS_NAME "stmpe-ts"
+#define XY_MASK 0xfff
+
+/**
+ * struct stmpe_touch - stmpe811 touch screen controller state
+ * @stmpe: pointer back to STMPE MFD container
+ * @idev: registered input device
+ * @work: a work item used to scan the device
+ * @dev: a pointer back to the MFD cell struct device*
+ * @prop: Touchscreen properties
+ * @ave_ctrl: Sample average control
+ * (0 -> 1 sample, 1 -> 2 samples, 2 -> 4 samples, 3 -> 8 samples)
+ * @touch_det_delay: Touch detect interrupt delay
+ * (0 -> 10 us, 1 -> 50 us, 2 -> 100 us, 3 -> 500 us,
+ * 4-> 1 ms, 5 -> 5 ms, 6 -> 10 ms, 7 -> 50 ms)
+ * recommended is 3
+ * @settling: Panel driver settling time
+ * (0 -> 10 us, 1 -> 100 us, 2 -> 500 us, 3 -> 1 ms,
+ * 4 -> 5 ms, 5 -> 10 ms, 6 for 50 ms, 7 -> 100 ms)
+ * recommended is 2
+ * @fraction_z: Length of the fractional part in z
+ * (fraction_z ([0..7]) = Count of the fractional part)
+ * recommended is 7
+ * @i_drive: current limit value of the touchscreen drivers
+ * (0 -> 20 mA typical 35 mA max, 1 -> 50 mA typical 80 mA max)
+ */
+struct stmpe_touch {
+ struct stmpe *stmpe;
+ struct input_dev *idev;
+ struct delayed_work work;
+ struct device *dev;
+ struct touchscreen_properties prop;
+ u8 ave_ctrl;
+ u8 touch_det_delay;
+ u8 settling;
+ u8 fraction_z;
+ u8 i_drive;
+};
+
+static int __stmpe_reset_fifo(struct stmpe *stmpe)
+{
+ int ret;
+
+ ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
+ STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET);
+ if (ret)
+ return ret;
+
+ return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
+ STMPE_FIFO_STA_RESET, 0);
+}
+
+static void stmpe_work(struct work_struct *work)
+{
+ int int_sta;
+ u32 timeout = 40;
+
+ struct stmpe_touch *ts =
+ container_of(work, struct stmpe_touch, work.work);
+
+ int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
+
+ /*
+ * touch_det sometimes get desasserted or just get stuck. This appears
+ * to be a silicon bug, We still have to clearify this with the
+ * manufacture. As a workaround We release the key anyway if the
+ * touch_det keeps coming in after 4ms, while the FIFO contains no value
+ * during the whole time.
+ */
+ while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) {
+ timeout--;
+ int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
+ udelay(100);
+ }
+
+ /* reset the FIFO before we report release event */
+ __stmpe_reset_fifo(ts->stmpe);
+
+ input_report_abs(ts->idev, ABS_PRESSURE, 0);
+ input_report_key(ts->idev, BTN_TOUCH, 0);
+ input_sync(ts->idev);
+}
+
+static irqreturn_t stmpe_ts_handler(int irq, void *data)
+{
+ u8 data_set[4];
+ int x, y, z;
+ struct stmpe_touch *ts = data;
+
+ /*
+ * Cancel scheduled polling for release if we have new value
+ * available. Wait if the polling is already running.
+ */
+ cancel_delayed_work_sync(&ts->work);
+
+ /*
+ * The FIFO sometimes just crashes and stops generating interrupts. This
+ * appears to be a silicon bug. We still have to clearify this with
+ * the manufacture. As a workaround we disable the TSC while we are
+ * collecting data and flush the FIFO after reading
+ */
+ stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
+ STMPE_TSC_CTRL_TSC_EN, 0);
+
+ stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set);
+
+ x = (data_set[0] << 4) | (data_set[1] >> 4);
+ y = ((data_set[1] & 0xf) << 8) | data_set[2];
+ z = data_set[3];
+
+ touchscreen_report_pos(ts->idev, &ts->prop, x, y, false);
+ input_report_abs(ts->idev, ABS_PRESSURE, z);
+ input_report_key(ts->idev, BTN_TOUCH, 1);
+ input_sync(ts->idev);
+
+ /* flush the FIFO after we have read out our values. */
+ __stmpe_reset_fifo(ts->stmpe);
+
+ /* reenable the tsc */
+ stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
+ STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
+
+ /* start polling for touch_det to detect release */
+ schedule_delayed_work(&ts->work, msecs_to_jiffies(50));
+
+ return IRQ_HANDLED;
+}
+
+static int stmpe_init_hw(struct stmpe_touch *ts)
+{
+ int ret;
+ u8 tsc_cfg, tsc_cfg_mask;
+ struct stmpe *stmpe = ts->stmpe;
+ struct device *dev = ts->dev;
+
+ ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC);
+ if (ret) {
+ dev_err(dev, "Could not enable clock for ADC and TS\n");
+ return ret;
+ }
+
+ ret = stmpe811_adc_common_init(stmpe);
+ if (ret) {
+ stmpe_disable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC);
+ return ret;
+ }
+
+ tsc_cfg = STMPE_AVE_CTRL(ts->ave_ctrl) |
+ STMPE_DET_DELAY(ts->touch_det_delay) |
+ STMPE_SETTLING(ts->settling);
+ tsc_cfg_mask = STMPE_AVE_CTRL(0xff) | STMPE_DET_DELAY(0xff) |
+ STMPE_SETTLING(0xff);
+
+ ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg);
+ if (ret) {
+ dev_err(dev, "Could not config touch\n");
+ return ret;
+ }
+
+ ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z,
+ STMPE_FRACTION_Z(0xff), STMPE_FRACTION_Z(ts->fraction_z));
+ if (ret) {
+ dev_err(dev, "Could not config touch\n");
+ return ret;
+ }
+
+ ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE,
+ STMPE_I_DRIVE(0xff), STMPE_I_DRIVE(ts->i_drive));
+ if (ret) {
+ dev_err(dev, "Could not config touch\n");
+ return ret;
+ }
+
+ /* set FIFO to 1 for single point reading */
+ ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1);
+ if (ret) {
+ dev_err(dev, "Could not set FIFO\n");
+ return ret;
+ }
+
+ ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL,
+ STMPE_OP_MODE(0xff), STMPE_OP_MODE(OP_MOD_XYZ));
+ if (ret) {
+ dev_err(dev, "Could not set mode\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int stmpe_ts_open(struct input_dev *dev)
+{
+ struct stmpe_touch *ts = input_get_drvdata(dev);
+ int ret = 0;
+
+ ret = __stmpe_reset_fifo(ts->stmpe);
+ if (ret)
+ return ret;
+
+ return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
+ STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
+}
+
+static void stmpe_ts_close(struct input_dev *dev)
+{
+ struct stmpe_touch *ts = input_get_drvdata(dev);
+
+ cancel_delayed_work_sync(&ts->work);
+
+ stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
+ STMPE_TSC_CTRL_TSC_EN, 0);
+}
+
+static void stmpe_ts_get_platform_info(struct platform_device *pdev,
+ struct stmpe_touch *ts)
+{
+ struct device_node *np = pdev->dev.of_node;
+ u32 val;
+
+ if (np) {
+ if (!of_property_read_u32(np, "st,sample-time", &val))
+ ts->stmpe->sample_time = val;
+ if (!of_property_read_u32(np, "st,mod-12b", &val))
+ ts->stmpe->mod_12b = val;
+ if (!of_property_read_u32(np, "st,ref-sel", &val))
+ ts->stmpe->ref_sel = val;
+ if (!of_property_read_u32(np, "st,adc-freq", &val))
+ ts->stmpe->adc_freq = val;
+ if (!of_property_read_u32(np, "st,ave-ctrl", &val))
+ ts->ave_ctrl = val;
+ if (!of_property_read_u32(np, "st,touch-det-delay", &val))
+ ts->touch_det_delay = val;
+ if (!of_property_read_u32(np, "st,settling", &val))
+ ts->settling = val;
+ if (!of_property_read_u32(np, "st,fraction-z", &val))
+ ts->fraction_z = val;
+ if (!of_property_read_u32(np, "st,i-drive", &val))
+ ts->i_drive = val;
+ }
+}
+
+static int stmpe_input_probe(struct platform_device *pdev)
+{
+ struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
+ struct stmpe_touch *ts;
+ struct input_dev *idev;
+ int error;
+ int ts_irq;
+
+ ts_irq = platform_get_irq_byname(pdev, "FIFO_TH");
+ if (ts_irq < 0)
+ return ts_irq;
+
+ ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ idev = devm_input_allocate_device(&pdev->dev);
+ if (!idev)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, ts);
+ ts->stmpe = stmpe;
+ ts->idev = idev;
+ ts->dev = &pdev->dev;
+
+ stmpe_ts_get_platform_info(pdev, ts);
+
+ INIT_DELAYED_WORK(&ts->work, stmpe_work);
+
+ error = devm_request_threaded_irq(&pdev->dev, ts_irq,
+ NULL, stmpe_ts_handler,
+ IRQF_ONESHOT, STMPE_TS_NAME, ts);
+ if (error) {
+ dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq);
+ return error;
+ }
+
+ error = stmpe_init_hw(ts);
+ if (error)
+ return error;
+
+ idev->name = STMPE_TS_NAME;
+ idev->phys = STMPE_TS_NAME"/input0";
+ idev->id.bustype = BUS_I2C;
+
+ idev->open = stmpe_ts_open;
+ idev->close = stmpe_ts_close;
+
+ input_set_drvdata(idev, ts);
+
+ input_set_capability(idev, EV_KEY, BTN_TOUCH);
+ input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0);
+ input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0);
+ input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0);
+
+ touchscreen_parse_properties(idev, false, &ts->prop);
+
+ error = input_register_device(idev);
+ if (error) {
+ dev_err(&pdev->dev, "Could not register input device\n");
+ return error;
+ }
+
+ return 0;
+}
+
+static int stmpe_ts_remove(struct platform_device *pdev)
+{
+ struct stmpe_touch *ts = platform_get_drvdata(pdev);
+
+ stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN);
+
+ return 0;
+}
+
+static struct platform_driver stmpe_ts_driver = {
+ .driver = {
+ .name = STMPE_TS_NAME,
+ },
+ .probe = stmpe_input_probe,
+ .remove = stmpe_ts_remove,
+};
+module_platform_driver(stmpe_ts_driver);
+
+static const struct of_device_id stmpe_ts_ids[] = {
+ { .compatible = "st,stmpe-ts", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, stmpe_ts_ids);
+
+MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
+MODULE_DESCRIPTION("STMPEXXX touchscreen driver");
+MODULE_LICENSE("GPL");