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Diffstat (limited to 'drivers/input/touchscreen/ti_am335x_tsc.c')
-rw-r--r--drivers/input/touchscreen/ti_am335x_tsc.c559
1 files changed, 559 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
new file mode 100644
index 000000000..83e685557
--- /dev/null
+++ b/drivers/input/touchscreen/ti_am335x_tsc.c
@@ -0,0 +1,559 @@
+/*
+ * TI Touch Screen driver
+ *
+ * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/sort.h>
+#include <linux/pm_wakeirq.h>
+
+#include <linux/mfd/ti_am335x_tscadc.h>
+
+#define ADCFSM_STEPID 0x10
+#define SEQ_SETTLE 275
+#define MAX_12BIT ((1 << 12) - 1)
+
+#define TSC_IRQENB_MASK (IRQENB_FIFO0THRES | IRQENB_EOS | IRQENB_HW_PEN)
+
+static const int config_pins[] = {
+ STEPCONFIG_XPP,
+ STEPCONFIG_XNN,
+ STEPCONFIG_YPP,
+ STEPCONFIG_YNN,
+};
+
+struct titsc {
+ struct input_dev *input;
+ struct ti_tscadc_dev *mfd_tscadc;
+ struct device *dev;
+ unsigned int irq;
+ unsigned int wires;
+ unsigned int x_plate_resistance;
+ bool pen_down;
+ int coordinate_readouts;
+ u32 config_inp[4];
+ u32 bit_xp, bit_xn, bit_yp, bit_yn;
+ u32 inp_xp, inp_xn, inp_yp, inp_yn;
+ u32 step_mask;
+ u32 charge_delay;
+};
+
+static unsigned int titsc_readl(struct titsc *ts, unsigned int reg)
+{
+ return readl(ts->mfd_tscadc->tscadc_base + reg);
+}
+
+static void titsc_writel(struct titsc *tsc, unsigned int reg,
+ unsigned int val)
+{
+ writel(val, tsc->mfd_tscadc->tscadc_base + reg);
+}
+
+static int titsc_config_wires(struct titsc *ts_dev)
+{
+ u32 analog_line[4];
+ u32 wire_order[4];
+ int i, bit_cfg;
+
+ for (i = 0; i < 4; i++) {
+ /*
+ * Get the order in which TSC wires are attached
+ * w.r.t. each of the analog input lines on the EVM.
+ */
+ analog_line[i] = (ts_dev->config_inp[i] & 0xF0) >> 4;
+ wire_order[i] = ts_dev->config_inp[i] & 0x0F;
+ if (WARN_ON(analog_line[i] > 7))
+ return -EINVAL;
+ if (WARN_ON(wire_order[i] > ARRAY_SIZE(config_pins)))
+ return -EINVAL;
+ }
+
+ for (i = 0; i < 4; i++) {
+ int an_line;
+ int wi_order;
+
+ an_line = analog_line[i];
+ wi_order = wire_order[i];
+ bit_cfg = config_pins[wi_order];
+ if (bit_cfg == 0)
+ return -EINVAL;
+ switch (wi_order) {
+ case 0:
+ ts_dev->bit_xp = bit_cfg;
+ ts_dev->inp_xp = an_line;
+ break;
+
+ case 1:
+ ts_dev->bit_xn = bit_cfg;
+ ts_dev->inp_xn = an_line;
+ break;
+
+ case 2:
+ ts_dev->bit_yp = bit_cfg;
+ ts_dev->inp_yp = an_line;
+ break;
+ case 3:
+ ts_dev->bit_yn = bit_cfg;
+ ts_dev->inp_yn = an_line;
+ break;
+ }
+ }
+ return 0;
+}
+
+static void titsc_step_config(struct titsc *ts_dev)
+{
+ unsigned int config;
+ int i;
+ int end_step, first_step, tsc_steps;
+ u32 stepenable;
+
+ config = STEPCONFIG_MODE_HWSYNC |
+ STEPCONFIG_AVG_16 | ts_dev->bit_xp;
+ switch (ts_dev->wires) {
+ case 4:
+ config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
+ break;
+ case 5:
+ config |= ts_dev->bit_yn |
+ STEPCONFIG_INP_AN4 | ts_dev->bit_xn |
+ ts_dev->bit_yp;
+ break;
+ case 8:
+ config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
+ break;
+ }
+
+ tsc_steps = ts_dev->coordinate_readouts * 2 + 2;
+ first_step = TOTAL_STEPS - tsc_steps;
+ /* Steps 16 to 16-coordinate_readouts is for X */
+ end_step = first_step + tsc_steps;
+ for (i = end_step - ts_dev->coordinate_readouts; i < end_step; i++) {
+ titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
+ titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
+ }
+
+ config = 0;
+ config = STEPCONFIG_MODE_HWSYNC |
+ STEPCONFIG_AVG_16 | ts_dev->bit_yn |
+ STEPCONFIG_INM_ADCREFM;
+ switch (ts_dev->wires) {
+ case 4:
+ config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
+ break;
+ case 5:
+ config |= ts_dev->bit_xp | STEPCONFIG_INP_AN4 |
+ STEPCONFIG_XNP | STEPCONFIG_YPN;
+ break;
+ case 8:
+ config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
+ break;
+ }
+
+ /* 1 ... coordinate_readouts is for Y */
+ end_step = first_step + ts_dev->coordinate_readouts;
+ for (i = first_step; i < end_step; i++) {
+ titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
+ titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
+ }
+
+ /* Make CHARGECONFIG same as IDLECONFIG */
+
+ config = titsc_readl(ts_dev, REG_IDLECONFIG);
+ titsc_writel(ts_dev, REG_CHARGECONFIG, config);
+ titsc_writel(ts_dev, REG_CHARGEDELAY, ts_dev->charge_delay);
+
+ /* coordinate_readouts + 1 ... coordinate_readouts + 2 is for Z */
+ config = STEPCONFIG_MODE_HWSYNC |
+ STEPCONFIG_AVG_16 | ts_dev->bit_yp |
+ ts_dev->bit_xn | STEPCONFIG_INM_ADCREFM |
+ STEPCONFIG_INP(ts_dev->inp_xp);
+ titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
+ titsc_writel(ts_dev, REG_STEPDELAY(end_step),
+ STEPCONFIG_OPENDLY);
+
+ end_step++;
+ config |= STEPCONFIG_INP(ts_dev->inp_yn);
+ titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
+ titsc_writel(ts_dev, REG_STEPDELAY(end_step),
+ STEPCONFIG_OPENDLY);
+
+ /* The steps end ... end - readouts * 2 + 2 and bit 0 for TS_Charge */
+ stepenable = 1;
+ for (i = 0; i < tsc_steps; i++)
+ stepenable |= 1 << (first_step + i + 1);
+
+ ts_dev->step_mask = stepenable;
+ am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask);
+}
+
+static int titsc_cmp_coord(const void *a, const void *b)
+{
+ return *(int *)a - *(int *)b;
+}
+
+static void titsc_read_coordinates(struct titsc *ts_dev,
+ u32 *x, u32 *y, u32 *z1, u32 *z2)
+{
+ unsigned int yvals[7], xvals[7];
+ unsigned int i, xsum = 0, ysum = 0;
+ unsigned int creads = ts_dev->coordinate_readouts;
+
+ for (i = 0; i < creads; i++) {
+ yvals[i] = titsc_readl(ts_dev, REG_FIFO0);
+ yvals[i] &= 0xfff;
+ }
+
+ *z1 = titsc_readl(ts_dev, REG_FIFO0);
+ *z1 &= 0xfff;
+ *z2 = titsc_readl(ts_dev, REG_FIFO0);
+ *z2 &= 0xfff;
+
+ for (i = 0; i < creads; i++) {
+ xvals[i] = titsc_readl(ts_dev, REG_FIFO0);
+ xvals[i] &= 0xfff;
+ }
+
+ /*
+ * If co-ordinates readouts is less than 4 then
+ * report the average. In case of 4 or more
+ * readouts, sort the co-ordinate samples, drop
+ * min and max values and report the average of
+ * remaining values.
+ */
+ if (creads <= 3) {
+ for (i = 0; i < creads; i++) {
+ ysum += yvals[i];
+ xsum += xvals[i];
+ }
+ ysum /= creads;
+ xsum /= creads;
+ } else {
+ sort(yvals, creads, sizeof(unsigned int),
+ titsc_cmp_coord, NULL);
+ sort(xvals, creads, sizeof(unsigned int),
+ titsc_cmp_coord, NULL);
+ for (i = 1; i < creads - 1; i++) {
+ ysum += yvals[i];
+ xsum += xvals[i];
+ }
+ ysum /= creads - 2;
+ xsum /= creads - 2;
+ }
+ *y = ysum;
+ *x = xsum;
+}
+
+static irqreturn_t titsc_irq(int irq, void *dev)
+{
+ struct titsc *ts_dev = dev;
+ struct input_dev *input_dev = ts_dev->input;
+ unsigned int fsm, status, irqclr = 0;
+ unsigned int x = 0, y = 0;
+ unsigned int z1, z2, z;
+
+ status = titsc_readl(ts_dev, REG_RAWIRQSTATUS);
+ if (status & IRQENB_HW_PEN) {
+ ts_dev->pen_down = true;
+ irqclr |= IRQENB_HW_PEN;
+ pm_stay_awake(ts_dev->dev);
+ }
+
+ if (status & IRQENB_PENUP) {
+ fsm = titsc_readl(ts_dev, REG_ADCFSM);
+ if (fsm == ADCFSM_STEPID) {
+ ts_dev->pen_down = false;
+ input_report_key(input_dev, BTN_TOUCH, 0);
+ input_report_abs(input_dev, ABS_PRESSURE, 0);
+ input_sync(input_dev);
+ pm_relax(ts_dev->dev);
+ } else {
+ ts_dev->pen_down = true;
+ }
+ irqclr |= IRQENB_PENUP;
+ }
+
+ if (status & IRQENB_EOS)
+ irqclr |= IRQENB_EOS;
+
+ /*
+ * ADC and touchscreen share the IRQ line.
+ * FIFO1 interrupts are used by ADC. Handle FIFO0 IRQs here only
+ */
+ if (status & IRQENB_FIFO0THRES) {
+
+ titsc_read_coordinates(ts_dev, &x, &y, &z1, &z2);
+
+ if (ts_dev->pen_down && z1 != 0 && z2 != 0) {
+ /*
+ * Calculate pressure using formula
+ * Resistance(touch) = x plate resistance *
+ * x postion/4096 * ((z2 / z1) - 1)
+ */
+ z = z1 - z2;
+ z *= x;
+ z *= ts_dev->x_plate_resistance;
+ z /= z2;
+ z = (z + 2047) >> 12;
+
+ if (z <= MAX_12BIT) {
+ input_report_abs(input_dev, ABS_X, x);
+ input_report_abs(input_dev, ABS_Y, y);
+ input_report_abs(input_dev, ABS_PRESSURE, z);
+ input_report_key(input_dev, BTN_TOUCH, 1);
+ input_sync(input_dev);
+ }
+ }
+ irqclr |= IRQENB_FIFO0THRES;
+ }
+ if (irqclr) {
+ titsc_writel(ts_dev, REG_IRQSTATUS, irqclr);
+ if (status & IRQENB_EOS)
+ am335x_tsc_se_set_cache(ts_dev->mfd_tscadc,
+ ts_dev->step_mask);
+ return IRQ_HANDLED;
+ }
+ return IRQ_NONE;
+}
+
+static int titsc_parse_dt(struct platform_device *pdev,
+ struct titsc *ts_dev)
+{
+ struct device_node *node = pdev->dev.of_node;
+ int err;
+
+ if (!node)
+ return -EINVAL;
+
+ err = of_property_read_u32(node, "ti,wires", &ts_dev->wires);
+ if (err < 0)
+ return err;
+ switch (ts_dev->wires) {
+ case 4:
+ case 5:
+ case 8:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ err = of_property_read_u32(node, "ti,x-plate-resistance",
+ &ts_dev->x_plate_resistance);
+ if (err < 0)
+ return err;
+
+ /*
+ * Try with the new binding first. If it fails, try again with
+ * bogus, miss-spelled version.
+ */
+ err = of_property_read_u32(node, "ti,coordinate-readouts",
+ &ts_dev->coordinate_readouts);
+ if (err < 0) {
+ dev_warn(&pdev->dev, "please use 'ti,coordinate-readouts' instead\n");
+ err = of_property_read_u32(node, "ti,coordiante-readouts",
+ &ts_dev->coordinate_readouts);
+ }
+
+ if (err < 0)
+ return err;
+
+ if (ts_dev->coordinate_readouts <= 0) {
+ dev_warn(&pdev->dev,
+ "invalid co-ordinate readouts, resetting it to 5\n");
+ ts_dev->coordinate_readouts = 5;
+ }
+
+ err = of_property_read_u32(node, "ti,charge-delay",
+ &ts_dev->charge_delay);
+ /*
+ * If ti,charge-delay value is not specified, then use
+ * CHARGEDLY_OPENDLY as the default value.
+ */
+ if (err < 0) {
+ ts_dev->charge_delay = CHARGEDLY_OPENDLY;
+ dev_warn(&pdev->dev, "ti,charge-delay not specified\n");
+ }
+
+ return of_property_read_u32_array(node, "ti,wire-config",
+ ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp));
+}
+
+/*
+ * The functions for inserting/removing driver as a module.
+ */
+
+static int titsc_probe(struct platform_device *pdev)
+{
+ struct titsc *ts_dev;
+ struct input_dev *input_dev;
+ struct ti_tscadc_dev *tscadc_dev = ti_tscadc_dev_get(pdev);
+ int err;
+
+ /* Allocate memory for device */
+ ts_dev = kzalloc(sizeof(*ts_dev), GFP_KERNEL);
+ input_dev = input_allocate_device();
+ if (!ts_dev || !input_dev) {
+ dev_err(&pdev->dev, "failed to allocate memory.\n");
+ err = -ENOMEM;
+ goto err_free_mem;
+ }
+
+ tscadc_dev->tsc = ts_dev;
+ ts_dev->mfd_tscadc = tscadc_dev;
+ ts_dev->input = input_dev;
+ ts_dev->irq = tscadc_dev->irq;
+ ts_dev->dev = &pdev->dev;
+
+ err = titsc_parse_dt(pdev, ts_dev);
+ if (err) {
+ dev_err(&pdev->dev, "Could not find valid DT data.\n");
+ goto err_free_mem;
+ }
+
+ err = request_irq(ts_dev->irq, titsc_irq,
+ IRQF_SHARED, pdev->dev.driver->name, ts_dev);
+ if (err) {
+ dev_err(&pdev->dev, "failed to allocate irq.\n");
+ goto err_free_mem;
+ }
+
+ device_init_wakeup(&pdev->dev, true);
+ err = dev_pm_set_wake_irq(&pdev->dev, ts_dev->irq);
+ if (err)
+ dev_err(&pdev->dev, "irq wake enable failed.\n");
+
+ titsc_writel(ts_dev, REG_IRQSTATUS, TSC_IRQENB_MASK);
+ titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO0THRES);
+ titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_EOS);
+ err = titsc_config_wires(ts_dev);
+ if (err) {
+ dev_err(&pdev->dev, "wrong i/p wire configuration\n");
+ goto err_free_irq;
+ }
+ titsc_step_config(ts_dev);
+ titsc_writel(ts_dev, REG_FIFO0THR,
+ ts_dev->coordinate_readouts * 2 + 2 - 1);
+
+ input_dev->name = "ti-tsc";
+ input_dev->dev.parent = &pdev->dev;
+
+ input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+ input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(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);
+ input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
+
+ /* register to the input system */
+ err = input_register_device(input_dev);
+ if (err)
+ goto err_free_irq;
+
+ platform_set_drvdata(pdev, ts_dev);
+ return 0;
+
+err_free_irq:
+ dev_pm_clear_wake_irq(&pdev->dev);
+ device_init_wakeup(&pdev->dev, false);
+ free_irq(ts_dev->irq, ts_dev);
+err_free_mem:
+ input_free_device(input_dev);
+ kfree(ts_dev);
+ return err;
+}
+
+static int titsc_remove(struct platform_device *pdev)
+{
+ struct titsc *ts_dev = platform_get_drvdata(pdev);
+ u32 steps;
+
+ dev_pm_clear_wake_irq(&pdev->dev);
+ device_init_wakeup(&pdev->dev, false);
+ free_irq(ts_dev->irq, ts_dev);
+
+ /* total steps followed by the enable mask */
+ steps = 2 * ts_dev->coordinate_readouts + 2;
+ steps = (1 << steps) - 1;
+ am335x_tsc_se_clr(ts_dev->mfd_tscadc, steps);
+
+ input_unregister_device(ts_dev->input);
+
+ kfree(ts_dev);
+ return 0;
+}
+
+static int __maybe_unused titsc_suspend(struct device *dev)
+{
+ struct titsc *ts_dev = dev_get_drvdata(dev);
+ unsigned int idle;
+
+ if (device_may_wakeup(dev)) {
+ titsc_writel(ts_dev, REG_IRQSTATUS, TSC_IRQENB_MASK);
+ idle = titsc_readl(ts_dev, REG_IRQENABLE);
+ titsc_writel(ts_dev, REG_IRQENABLE,
+ (idle | IRQENB_HW_PEN));
+ titsc_writel(ts_dev, REG_IRQWAKEUP, IRQWKUP_ENB);
+ }
+ return 0;
+}
+
+static int __maybe_unused titsc_resume(struct device *dev)
+{
+ struct titsc *ts_dev = dev_get_drvdata(dev);
+
+ if (device_may_wakeup(dev)) {
+ titsc_writel(ts_dev, REG_IRQWAKEUP,
+ 0x00);
+ titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
+ pm_relax(dev);
+ }
+ titsc_step_config(ts_dev);
+ titsc_writel(ts_dev, REG_FIFO0THR,
+ ts_dev->coordinate_readouts * 2 + 2 - 1);
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(titsc_pm_ops, titsc_suspend, titsc_resume);
+
+static const struct of_device_id ti_tsc_dt_ids[] = {
+ { .compatible = "ti,am3359-tsc", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ti_tsc_dt_ids);
+
+static struct platform_driver ti_tsc_driver = {
+ .probe = titsc_probe,
+ .remove = titsc_remove,
+ .driver = {
+ .name = "TI-am335x-tsc",
+ .pm = &titsc_pm_ops,
+ .of_match_table = ti_tsc_dt_ids,
+ },
+};
+module_platform_driver(ti_tsc_driver);
+
+MODULE_DESCRIPTION("TI touchscreen controller driver");
+MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
+MODULE_LICENSE("GPL");