Input: add support for DA9052/53 touch screen controller

This driver adds support for DA9052/53 4-wire resistive ADC interfaced
touchscreen controller. DA9052/53 is a multi-function device, therefore
this driver depends on DA9052/53 core.

This patch is functionally tested on Samsung SMDKV6410.

Signed-off-by: David Dajun Chen <dchen@diasemi.com>
Signed-off-by: Ashish Jangam <ashish.jangam@kpitcummins.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 370 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/da9052_tsi.c b/drivers/input/touchscreen/da9052_tsi.c
new file mode 100644
index 000000000000..e8df341090c0
--- /dev/null
+++ b/drivers/input/touchscreen/da9052_tsi.c
@@ -0,0 +1,370 @@
+/*
+ * TSI driver for Dialog DA9052
+ *
+ * Copyright(c) 2012 Dialog Semiconductor Ltd.
+ *
+ * Author: David Dajun Chen <dchen@diasemi.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;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ *
+ */
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+
+#include <linux/mfd/da9052/reg.h>
+#include <linux/mfd/da9052/da9052.h>
+
+#define TSI_PEN_DOWN_STATUS 0x40
+
+struct da9052_tsi {
+        struct da9052 *da9052;
+        struct input_dev *dev;
+        struct delayed_work ts_pen_work;
+        struct mutex mutex;
+        unsigned int irq_pendwn;
+        unsigned int irq_datardy;
+        bool stopped;
+        bool adc_on;
+};
+
+static void da9052_ts_adc_toggle(struct da9052_tsi *tsi, bool on)
+{
+        da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 0, on);
+        tsi->adc_on = on;
+}
+
+static irqreturn_t da9052_ts_pendwn_irq(int irq, void *data)
+{
+        struct da9052_tsi *tsi = data;
+
+        if (!tsi->stopped) {
+                /* Mask PEN_DOWN event and unmask TSI_READY event */
+                disable_irq_nosync(tsi->irq_pendwn);
+                enable_irq(tsi->irq_datardy);
+
+                da9052_ts_adc_toggle(tsi, true);
+
+                schedule_delayed_work(&tsi->ts_pen_work, HZ / 50);
+        }
+
+        return IRQ_HANDLED;
+}
+
+static void da9052_ts_read(struct da9052_tsi *tsi)
+{
+        struct input_dev *input = tsi->dev;
+        int ret;
+        u16 x, y, z;
+        u8 v;
+
+        ret = da9052_reg_read(tsi->da9052, DA9052_TSI_X_MSB_REG);
+        if (ret < 0)
+                return;
+
+        x = (u16) ret;
+
+        ret = da9052_reg_read(tsi->da9052, DA9052_TSI_Y_MSB_REG);
+        if (ret < 0)
+                return;
+
+        y = (u16) ret;
+
+        ret = da9052_reg_read(tsi->da9052, DA9052_TSI_Z_MSB_REG);
+        if (ret < 0)
+                return;
+
+        z = (u16) ret;
+
+        ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
+        if (ret < 0)
+                return;
+
+        v = (u8) ret;
+
+        x = ((x << 2) & 0x3fc) | (v & 0x3);
+        y = ((y << 2) & 0x3fc) | ((v & 0xc) >> 2);
+        z = ((z << 2) & 0x3fc) | ((v & 0x30) >> 4);
+
+        input_report_key(input, BTN_TOUCH, 1);
+        input_report_abs(input, ABS_X, x);
+        input_report_abs(input, ABS_Y, y);
+        input_report_abs(input, ABS_PRESSURE, z);
+        input_sync(input);
+}
+
+static irqreturn_t da9052_ts_datardy_irq(int irq, void *data)
+{
+        struct da9052_tsi *tsi = data;
+
+        da9052_ts_read(tsi);
+
+        return IRQ_HANDLED;
+}
+
+static void da9052_ts_pen_work(struct work_struct *work)
+{
+        struct da9052_tsi *tsi = container_of(work, struct da9052_tsi,
+                                              ts_pen_work.work);
+        if (!tsi->stopped) {
+                int ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
+                if (ret < 0 || (ret & TSI_PEN_DOWN_STATUS)) {
+                        /* Pen is still DOWN (or read error) */
+                        schedule_delayed_work(&tsi->ts_pen_work, HZ / 50);
+                } else {
+                        struct input_dev *input = tsi->dev;
+
+                        /* Pen UP */
+                        da9052_ts_adc_toggle(tsi, false);
+
+                        /* Report Pen UP */
+                        input_report_key(input, BTN_TOUCH, 0);
+                        input_report_abs(input, ABS_PRESSURE, 0);
+                        input_sync(input);
+
+                        /*
+                         * FIXME: Fixes the unhandled irq issue when quick
+                         * pen down and pen up events occurs
+                         */
+                        ret = da9052_reg_update(tsi->da9052,
+                                                DA9052_EVENT_B_REG, 0xC0, 0xC0);
+                        if (ret < 0)
+                                return;
+
+                        /* Mask TSI_READY event and unmask PEN_DOWN event */
+                        disable_irq(tsi->irq_datardy);
+                        enable_irq(tsi->irq_pendwn);
+                }
+        }
+}
+
+static int __devinit da9052_ts_configure_gpio(struct da9052 *da9052)
+{
+        int error;
+
+        error = da9052_reg_update(da9052, DA9052_GPIO_2_3_REG, 0x30, 0);
+        if (error < 0)
+                return error;
+
+        error = da9052_reg_update(da9052, DA9052_GPIO_4_5_REG, 0x33, 0);
+        if (error < 0)
+                return error;
+
+        error = da9052_reg_update(da9052, DA9052_GPIO_6_7_REG, 0x33, 0);
+        if (error < 0)
+                return error;
+
+        return 0;
+}
+
+static int __devinit da9052_configure_tsi(struct da9052_tsi *tsi)
+{
+        int error;
+
+        error = da9052_ts_configure_gpio(tsi->da9052);
+        if (error)
+                return error;
+
+        /* Measure TSI sample every 1ms */
+        error = da9052_reg_update(tsi->da9052, DA9052_ADC_CONT_REG,
+                                  1 << 6, 1 << 6);
+        if (error < 0)
+                return error;
+
+        /* TSI_DELAY: 3 slots, TSI_SKIP: 0 slots, TSI_MODE: XYZP */
+        error = da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 0xFC, 0xC0);
+        if (error < 0)
+                return error;
+
+        /* Supply TSIRef through LD09 */
+        error = da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x59);
+        if (error < 0)
+                return error;
+
+        return 0;
+}
+
+static int da9052_ts_input_open(struct input_dev *input_dev)
+{
+        struct da9052_tsi *tsi = input_get_drvdata(input_dev);
+
+        tsi->stopped = false;
+        mb();
+
+        /* Unmask PEN_DOWN event */
+        enable_irq(tsi->irq_pendwn);
+
+        /* Enable Pen Detect Circuit */
+        return da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG,
+                                 1 << 1, 1 << 1);
+}
+
+static void da9052_ts_input_close(struct input_dev *input_dev)
+{
+        struct da9052_tsi *tsi = input_get_drvdata(input_dev);
+
+        tsi->stopped = true;
+        mb();
+        disable_irq(tsi->irq_pendwn);
+        cancel_delayed_work_sync(&tsi->ts_pen_work);
+
+        if (tsi->adc_on) {
+                disable_irq(tsi->irq_datardy);
+                da9052_ts_adc_toggle(tsi, false);
+
+                /*
+                 * If ADC was on that means that pendwn IRQ was disabled
+                 * twice and we need to enable it to keep enable/disable
+                 * counter balanced. IRQ is still off though.
+                 */
+                enable_irq(tsi->irq_pendwn);
+        }
+
+        /* Disable Pen Detect Circuit */
+        da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 1, 0);
+}
+
+static int __devinit da9052_ts_probe(struct platform_device *pdev)
+{
+        struct da9052 *da9052;
+        struct da9052_tsi *tsi;
+        struct input_dev *input_dev;
+        int irq_pendwn;
+        int irq_datardy;
+        int error;
+
+        da9052 = dev_get_drvdata(pdev->dev.parent);
+        if (!da9052)
+                return -EINVAL;
+
+        irq_pendwn = platform_get_irq_byname(pdev, "PENDWN");
+        irq_datardy = platform_get_irq_byname(pdev, "TSIRDY");
+        if (irq_pendwn < 0 || irq_datardy < 0) {
+                dev_err(da9052->dev, "Unable to determine device interrupts\n");
+                return -ENXIO;
+        }
+
+        tsi = kzalloc(sizeof(struct da9052_tsi), GFP_KERNEL);
+        input_dev = input_allocate_device();
+        if (!tsi || !input_dev) {
+                error = -ENOMEM;
+                goto err_free_mem;
+        }
+
+        tsi->da9052 = da9052;
+        tsi->dev = input_dev;
+        tsi->irq_pendwn = da9052->irq_base + irq_pendwn;
+        tsi->irq_datardy = da9052->irq_base + irq_datardy;
+        tsi->stopped = true;
+        INIT_DELAYED_WORK(&tsi->ts_pen_work, da9052_ts_pen_work);
+
+        input_dev->id.version = 0x0101;
+        input_dev->id.vendor = 0x15B6;
+        input_dev->id.product = 0x9052;
+        input_dev->name = "Dialog DA9052 TouchScreen Driver";
+        input_dev->dev.parent = &pdev->dev;
+        input_dev->open = da9052_ts_input_open;
+        input_dev->close = da9052_ts_input_close;
+
+        __set_bit(EV_ABS, input_dev->evbit);
+        __set_bit(EV_KEY, input_dev->evbit);
+        __set_bit(BTN_TOUCH, input_dev->keybit);
+
+        input_set_abs_params(input_dev, ABS_X, 0, 1023, 0, 0);
+        input_set_abs_params(input_dev, ABS_Y, 0, 1023, 0, 0);
+        input_set_abs_params(input_dev, ABS_PRESSURE, 0, 1023, 0, 0);
+
+        input_set_drvdata(input_dev, tsi);
+
+        /* Disable Pen Detect Circuit */
+        da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 1, 0);
+
+        /* Disable ADC */
+        da9052_ts_adc_toggle(tsi, false);
+
+        error = request_threaded_irq(tsi->irq_pendwn,
+                                     NULL, da9052_ts_pendwn_irq,
+                                     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+                                     "PENDWN", tsi);
+        if (error) {
+                dev_err(tsi->da9052->dev,
+                        "Failed to register PENDWN IRQ %d, error = %d\n",
+                        tsi->irq_pendwn, error);
+                goto err_free_mem;
+        }
+
+        error = request_threaded_irq(tsi->irq_datardy,
+                                     NULL, da9052_ts_datardy_irq,
+                                     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+                                     "TSIRDY", tsi);
+        if (error) {
+                dev_err(tsi->da9052->dev,
+                        "Failed to register TSIRDY IRQ %d, error = %d\n",
+                        tsi->irq_datardy, error);
+                goto err_free_pendwn_irq;
+        }
+
+        /* Mask PEN_DOWN and TSI_READY events */
+        disable_irq(tsi->irq_pendwn);
+        disable_irq(tsi->irq_datardy);
+
+        error = da9052_configure_tsi(tsi);
+        if (error)
+                goto err_free_datardy_irq;
+
+        error = input_register_device(tsi->dev);
+        if (error)
+                goto err_free_datardy_irq;
+
+        platform_set_drvdata(pdev, tsi);
+
+        return 0;
+
+err_free_datardy_irq:
+        free_irq(tsi->irq_datardy, tsi);
+err_free_pendwn_irq:
+        free_irq(tsi->irq_pendwn, tsi);
+err_free_mem:
+        kfree(tsi);
+        input_free_device(input_dev);
+
+        return error;
+}
+
+static int  __devexit da9052_ts_remove(struct platform_device *pdev)
+{
+        struct da9052_tsi *tsi = platform_get_drvdata(pdev);
+
+        da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x19);
+
+        free_irq(tsi->irq_pendwn, tsi);
+        free_irq(tsi->irq_datardy, tsi);
+
+        input_unregister_device(tsi->dev);
+        kfree(tsi);
+
+        platform_set_drvdata(pdev, NULL);
+
+        return 0;
+}
+
+static struct platform_driver da9052_tsi_driver = {
+        .probe  = da9052_ts_probe,
+        .remove = __devexit_p(da9052_ts_remove),
+        .driver = {
+                .name   = "da9052-tsi",
+                .owner  = THIS_MODULE,
+        },
+};
+
+module_platform_driver(da9052_tsi_driver);
+
+MODULE_DESCRIPTION("Touchscreen driver for Dialog Semiconductor DA9052");
+MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:da9052-tsi");