Input: add support for TI Touchscreen controller
This patch adds support for TI's touchscreen
controller for a 4/5/8 wire resistive panel
that is directly fed to the ADC.
This touchscreen controller will be part of
AM335x TI SoC. The TRM can be found at:
http://www.ti.com/lit/ug/spruh73a/spruh73a.pdf
Signed-off-by: Patil, Rachna <rachna@ti.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 2b21a70..5df719b 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -460,6 +460,18 @@
To compile this driver as a module, choose M here: the
module will be called touchwin.
+config TOUCHSCREEN_TI_TSCADC
+ tristate "TI Touchscreen Interface"
+ depends on ARCH_OMAP2PLUS
+ help
+ Say Y here if you have 4/5/8 wire touchscreen controller
+ to be connected to the ADC controller on your TI AM335x SoC.
+
+ If unsure, say N.
+
+ To compile this driver as a module, choose M here: the
+ module will be called ti_tscadc.
+
config TOUCHSCREEN_ATMEL_TSADCC
tristate "Atmel Touchscreen Interface"
depends on ARCH_AT91SAM9RL || ARCH_AT91SAM9G45
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index d9acbdc..e748fb8 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -48,6 +48,7 @@
obj-$(CONFIG_TOUCHSCREEN_S3C2410) += s3c2410_ts.o
obj-$(CONFIG_TOUCHSCREEN_ST1232) += st1232.o
obj-$(CONFIG_TOUCHSCREEN_STMPE) += stmpe-ts.o
+obj-$(CONFIG_TOUCHSCREEN_TI_TSCADC) += ti_tscadc.o
obj-$(CONFIG_TOUCHSCREEN_TNETV107X) += tnetv107x-ts.o
obj-$(CONFIG_TOUCHSCREEN_TOUCHIT213) += touchit213.o
obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT) += touchright.o
diff --git a/drivers/input/touchscreen/ti_tscadc.c b/drivers/input/touchscreen/ti_tscadc.c
new file mode 100644
index 0000000..d229c74
--- /dev/null
+++ b/drivers/input/touchscreen/ti_tscadc.c
@@ -0,0 +1,486 @@
+/*
+ * 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/init.h>
+#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/input/ti_tscadc.h>
+#include <linux/delay.h>
+
+#define REG_IRQEOI 0x020
+#define REG_RAWIRQSTATUS 0x024
+#define REG_IRQSTATUS 0x028
+#define REG_IRQENABLE 0x02C
+#define REG_IRQWAKEUP 0x034
+#define REG_CTRL 0x040
+#define REG_ADCFSM 0x044
+#define REG_CLKDIV 0x04C
+#define REG_SE 0x054
+#define REG_IDLECONFIG 0x058
+#define REG_CHARGECONFIG 0x05C
+#define REG_CHARGEDELAY 0x060
+#define REG_STEPCONFIG(n) (0x64 + ((n - 1) * 8))
+#define REG_STEPDELAY(n) (0x68 + ((n - 1) * 8))
+#define REG_STEPCONFIG13 0x0C4
+#define REG_STEPDELAY13 0x0C8
+#define REG_STEPCONFIG14 0x0CC
+#define REG_STEPDELAY14 0x0D0
+#define REG_FIFO0CNT 0xE4
+#define REG_FIFO1THR 0xF4
+#define REG_FIFO0 0x100
+#define REG_FIFO1 0x200
+
+/* Register Bitfields */
+#define IRQWKUP_ENB BIT(0)
+#define STPENB_STEPENB 0x7FFF
+#define IRQENB_FIFO1THRES BIT(5)
+#define IRQENB_PENUP BIT(9)
+#define STEPCONFIG_MODE_HWSYNC 0x2
+#define STEPCONFIG_SAMPLES_AVG (1 << 4)
+#define STEPCONFIG_XPP (1 << 5)
+#define STEPCONFIG_XNN (1 << 6)
+#define STEPCONFIG_YPP (1 << 7)
+#define STEPCONFIG_YNN (1 << 8)
+#define STEPCONFIG_XNP (1 << 9)
+#define STEPCONFIG_YPN (1 << 10)
+#define STEPCONFIG_INM (1 << 18)
+#define STEPCONFIG_INP (1 << 20)
+#define STEPCONFIG_INP_5 (1 << 21)
+#define STEPCONFIG_FIFO1 (1 << 26)
+#define STEPCONFIG_OPENDLY 0xff
+#define STEPCONFIG_Z1 (3 << 19)
+#define STEPIDLE_INP (1 << 22)
+#define STEPCHARGE_RFP (1 << 12)
+#define STEPCHARGE_INM (1 << 15)
+#define STEPCHARGE_INP (1 << 19)
+#define STEPCHARGE_RFM (1 << 23)
+#define STEPCHARGE_DELAY 0x1
+#define CNTRLREG_TSCSSENB (1 << 0)
+#define CNTRLREG_STEPID (1 << 1)
+#define CNTRLREG_STEPCONFIGWRT (1 << 2)
+#define CNTRLREG_4WIRE (1 << 5)
+#define CNTRLREG_5WIRE (1 << 6)
+#define CNTRLREG_8WIRE (3 << 5)
+#define CNTRLREG_TSCENB (1 << 7)
+#define ADCFSM_STEPID 0x10
+
+#define SEQ_SETTLE 275
+#define ADC_CLK 3000000
+#define MAX_12BIT ((1 << 12) - 1)
+#define TSCADC_DELTA_X 15
+#define TSCADC_DELTA_Y 15
+
+struct tscadc {
+ struct input_dev *input;
+ struct clk *tsc_ick;
+ void __iomem *tsc_base;
+ unsigned int irq;
+ unsigned int wires;
+ unsigned int x_plate_resistance;
+ bool pen_down;
+};
+
+static unsigned int tscadc_readl(struct tscadc *ts, unsigned int reg)
+{
+ return readl(ts->tsc_base + reg);
+}
+
+static void tscadc_writel(struct tscadc *tsc, unsigned int reg,
+ unsigned int val)
+{
+ writel(val, tsc->tsc_base + reg);
+}
+
+static void tscadc_step_config(struct tscadc *ts_dev)
+{
+ unsigned int config;
+ int i;
+
+ /* Configure the Step registers */
+
+ config = STEPCONFIG_MODE_HWSYNC |
+ STEPCONFIG_SAMPLES_AVG | STEPCONFIG_XPP;
+ switch (ts_dev->wires) {
+ case 4:
+ config |= STEPCONFIG_INP | STEPCONFIG_XNN;
+ break;
+ case 5:
+ config |= STEPCONFIG_YNN |
+ STEPCONFIG_INP_5 | STEPCONFIG_XNN |
+ STEPCONFIG_YPP;
+ break;
+ case 8:
+ config |= STEPCONFIG_INP | STEPCONFIG_XNN;
+ break;
+ }
+
+ for (i = 1; i < 7; i++) {
+ tscadc_writel(ts_dev, REG_STEPCONFIG(i), config);
+ tscadc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
+ }
+
+ config = 0;
+ config = STEPCONFIG_MODE_HWSYNC |
+ STEPCONFIG_SAMPLES_AVG | STEPCONFIG_YNN |
+ STEPCONFIG_INM | STEPCONFIG_FIFO1;
+ switch (ts_dev->wires) {
+ case 4:
+ config |= STEPCONFIG_YPP;
+ break;
+ case 5:
+ config |= STEPCONFIG_XPP | STEPCONFIG_INP_5 |
+ STEPCONFIG_XNP | STEPCONFIG_YPN;
+ break;
+ case 8:
+ config |= STEPCONFIG_YPP;
+ break;
+ }
+
+ for (i = 7; i < 13; i++) {
+ tscadc_writel(ts_dev, REG_STEPCONFIG(i), config);
+ tscadc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
+ }
+
+ config = 0;
+ /* Charge step configuration */
+ config = STEPCONFIG_XPP | STEPCONFIG_YNN |
+ STEPCHARGE_RFP | STEPCHARGE_RFM |
+ STEPCHARGE_INM | STEPCHARGE_INP;
+
+ tscadc_writel(ts_dev, REG_CHARGECONFIG, config);
+ tscadc_writel(ts_dev, REG_CHARGEDELAY, STEPCHARGE_DELAY);
+
+ config = 0;
+ /* Configure to calculate pressure */
+ config = STEPCONFIG_MODE_HWSYNC |
+ STEPCONFIG_SAMPLES_AVG | STEPCONFIG_YPP |
+ STEPCONFIG_XNN | STEPCONFIG_INM;
+ tscadc_writel(ts_dev, REG_STEPCONFIG13, config);
+ tscadc_writel(ts_dev, REG_STEPDELAY13, STEPCONFIG_OPENDLY);
+
+ config |= STEPCONFIG_Z1 | STEPCONFIG_FIFO1;
+ tscadc_writel(ts_dev, REG_STEPCONFIG14, config);
+ tscadc_writel(ts_dev, REG_STEPDELAY14, STEPCONFIG_OPENDLY);
+
+ tscadc_writel(ts_dev, REG_SE, STPENB_STEPENB);
+}
+
+static void tscadc_idle_config(struct tscadc *ts_config)
+{
+ unsigned int idleconfig;
+
+ idleconfig = STEPCONFIG_YNN |
+ STEPCONFIG_INM |
+ STEPCONFIG_YPN | STEPIDLE_INP;
+ tscadc_writel(ts_config, REG_IDLECONFIG, idleconfig);
+}
+
+static void tscadc_read_coordinates(struct tscadc *ts_dev,
+ unsigned int *x, unsigned int *y)
+{
+ unsigned int fifocount = tscadc_readl(ts_dev, REG_FIFO0CNT);
+ unsigned int prev_val_x = ~0, prev_val_y = ~0;
+ unsigned int prev_diff_x = ~0, prev_diff_y = ~0;
+ unsigned int read, diff;
+ unsigned int i;
+
+ /*
+ * Delta filter is used to remove large variations in sampled
+ * values from ADC. The filter tries to predict where the next
+ * coordinate could be. This is done by taking a previous
+ * coordinate and subtracting it form current one. Further the
+ * algorithm compares the difference with that of a present value,
+ * if true the value is reported to the sub system.
+ */
+ for (i = 0; i < fifocount - 1; i++) {
+ read = tscadc_readl(ts_dev, REG_FIFO0) & 0xfff;
+ diff = abs(read - prev_val_x);
+ if (diff < prev_diff_x) {
+ prev_diff_x = diff;
+ *x = read;
+ }
+ prev_val_x = read;
+
+ read = tscadc_readl(ts_dev, REG_FIFO1) & 0xfff;
+ diff = abs(read - prev_val_y);
+ if (diff < prev_diff_y) {
+ prev_diff_y = diff;
+ *y = read;
+ }
+ prev_val_y = read;
+ }
+}
+
+static irqreturn_t tscadc_irq(int irq, void *dev)
+{
+ struct tscadc *ts_dev = dev;
+ struct input_dev *input_dev = ts_dev->input;
+ unsigned int status, irqclr = 0;
+ unsigned int x = 0, y = 0;
+ unsigned int z1, z2, z;
+ unsigned int fsm;
+
+ status = tscadc_readl(ts_dev, REG_IRQSTATUS);
+ if (status & IRQENB_FIFO1THRES) {
+ tscadc_read_coordinates(ts_dev, &x, &y);
+
+ z1 = tscadc_readl(ts_dev, REG_FIFO0) & 0xfff;
+ z2 = tscadc_readl(ts_dev, REG_FIFO1) & 0xfff;
+
+ 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 = z2 - z1;
+ z *= x;
+ z *= ts_dev->x_plate_resistance;
+ z /= z1;
+ 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_FIFO1THRES;
+ }
+
+ /*
+ * Time for sequencer to settle, to read
+ * correct state of the sequencer.
+ */
+ udelay(SEQ_SETTLE);
+
+ status = tscadc_readl(ts_dev, REG_RAWIRQSTATUS);
+ if (status & IRQENB_PENUP) {
+ /* Pen up event */
+ fsm = tscadc_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);
+ } else {
+ ts_dev->pen_down = true;
+ }
+ irqclr |= IRQENB_PENUP;
+ }
+
+ tscadc_writel(ts_dev, REG_IRQSTATUS, irqclr);
+ /* check pending interrupts */
+ tscadc_writel(ts_dev, REG_IRQEOI, 0x0);
+
+ tscadc_writel(ts_dev, REG_SE, STPENB_STEPENB);
+ return IRQ_HANDLED;
+}
+
+/*
+ * The functions for inserting/removing driver as a module.
+ */
+
+static int __devinit tscadc_probe(struct platform_device *pdev)
+{
+ const struct tsc_data *pdata = pdev->dev.platform_data;
+ struct resource *res;
+ struct tscadc *ts_dev;
+ struct input_dev *input_dev;
+ struct clk *clk;
+ int err;
+ int clk_value, ctrl, irq;
+
+ if (!pdata) {
+ dev_err(&pdev->dev, "missing platform data.\n");
+ return -EINVAL;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "no memory resource defined.\n");
+ return -EINVAL;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "no irq ID is specified.\n");
+ return -EINVAL;
+ }
+
+ /* Allocate memory for device */
+ ts_dev = kzalloc(sizeof(struct tscadc), 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;
+ }
+
+ ts_dev->input = input_dev;
+ ts_dev->irq = irq;
+ ts_dev->wires = pdata->wires;
+ ts_dev->x_plate_resistance = pdata->x_plate_resistance;
+
+ res = request_mem_region(res->start, resource_size(res), pdev->name);
+ if (!res) {
+ dev_err(&pdev->dev, "failed to reserve registers.\n");
+ err = -EBUSY;
+ goto err_free_mem;
+ }
+
+ ts_dev->tsc_base = ioremap(res->start, resource_size(res));
+ if (!ts_dev->tsc_base) {
+ dev_err(&pdev->dev, "failed to map registers.\n");
+ err = -ENOMEM;
+ goto err_release_mem_region;
+ }
+
+ err = request_irq(ts_dev->irq, tscadc_irq,
+ 0, pdev->dev.driver->name, ts_dev);
+ if (err) {
+ dev_err(&pdev->dev, "failed to allocate irq.\n");
+ goto err_unmap_regs;
+ }
+
+ ts_dev->tsc_ick = clk_get(&pdev->dev, "adc_tsc_ick");
+ if (IS_ERR(ts_dev->tsc_ick)) {
+ dev_err(&pdev->dev, "failed to get TSC ick\n");
+ goto err_free_irq;
+ }
+ clk_enable(ts_dev->tsc_ick);
+
+ clk = clk_get(&pdev->dev, "adc_tsc_fck");
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "failed to get TSC fck\n");
+ err = PTR_ERR(clk);
+ goto err_disable_clk;
+ }
+
+ clk_value = clk_get_rate(clk) / ADC_CLK;
+ clk_put(clk);
+
+ if (clk_value < 7) {
+ dev_err(&pdev->dev, "clock input less than min clock requirement\n");
+ goto err_disable_clk;
+ }
+ /* CLKDIV needs to be configured to the value minus 1 */
+ tscadc_writel(ts_dev, REG_CLKDIV, clk_value - 1);
+
+ /* Enable wake-up of the SoC using touchscreen */
+ tscadc_writel(ts_dev, REG_IRQWAKEUP, IRQWKUP_ENB);
+
+ ctrl = CNTRLREG_STEPCONFIGWRT |
+ CNTRLREG_TSCENB |
+ CNTRLREG_STEPID;
+ switch (ts_dev->wires) {
+ case 4:
+ ctrl |= CNTRLREG_4WIRE;
+ break;
+ case 5:
+ ctrl |= CNTRLREG_5WIRE;
+ break;
+ case 8:
+ ctrl |= CNTRLREG_8WIRE;
+ break;
+ }
+ tscadc_writel(ts_dev, REG_CTRL, ctrl);
+
+ tscadc_idle_config(ts_dev);
+ tscadc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO1THRES);
+ tscadc_step_config(ts_dev);
+ tscadc_writel(ts_dev, REG_FIFO1THR, 6);
+
+ ctrl |= CNTRLREG_TSCSSENB;
+ tscadc_writel(ts_dev, REG_CTRL, ctrl);
+
+ input_dev->name = "ti-tsc-adc";
+ 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_disable_clk;
+
+ platform_set_drvdata(pdev, ts_dev);
+ return 0;
+
+err_disable_clk:
+ clk_disable(ts_dev->tsc_ick);
+ clk_put(ts_dev->tsc_ick);
+err_free_irq:
+ free_irq(ts_dev->irq, ts_dev);
+err_unmap_regs:
+ iounmap(ts_dev->tsc_base);
+err_release_mem_region:
+ release_mem_region(res->start, resource_size(res));
+err_free_mem:
+ input_free_device(input_dev);
+ kfree(ts_dev);
+ return err;
+}
+
+static int __devexit tscadc_remove(struct platform_device *pdev)
+{
+ struct tscadc *ts_dev = platform_get_drvdata(pdev);
+ struct resource *res;
+
+ free_irq(ts_dev->irq, ts_dev);
+
+ input_unregister_device(ts_dev->input);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ iounmap(ts_dev->tsc_base);
+ release_mem_region(res->start, resource_size(res));
+
+ clk_disable(ts_dev->tsc_ick);
+ clk_put(ts_dev->tsc_ick);
+
+ kfree(ts_dev);
+
+ platform_set_drvdata(pdev, NULL);
+ return 0;
+}
+
+static struct platform_driver ti_tsc_driver = {
+ .probe = tscadc_probe,
+ .remove = __devexit_p(tscadc_remove),
+ .driver = {
+ .name = "tsc",
+ .owner = THIS_MODULE,
+ },
+};
+module_platform_driver(ti_tsc_driver);
+
+MODULE_DESCRIPTION("TI touchscreen controller driver");
+MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/input/ti_tscadc.h b/include/linux/input/ti_tscadc.h
new file mode 100644
index 0000000..b10a527
--- /dev/null
+++ b/include/linux/input/ti_tscadc.h
@@ -0,0 +1,17 @@
+#ifndef __LINUX_TI_TSCADC_H
+#define __LINUX_TI_TSCADC_H
+
+/**
+ * struct tsc_data Touchscreen wire configuration
+ * @wires: Wires refer to application modes
+ * i.e. 4/5/8 wire touchscreen support
+ * on the platform.
+ * @x_plate_resistance: X plate resistance.
+ */
+
+struct tsc_data {
+ int wires;
+ int x_plate_resistance;
+};
+
+#endif