Input: add Cypress TTSP capacitive multi-touch screen support

Cypress TrueTouch(tm) Standard Product controllers are found in
a wide range of embedded devices. This driver add support for a
variety of TTSP controllers.

Since the hardware is capable of tracking identifiable contacts, multi-touch
protocol type B (stateful) is used to report contact information.

The driver is composed of a core driver that process the data sent by
the contacts and a set of bus specific interface modules. This patch
adds the base core TTSP driver.

Signed-off-by: Javier Martinez Canillas <javier@dowhile0.org>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 625 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/cyttsp_core.c b/drivers/input/touchscreen/cyttsp_core.c
new file mode 100644
index 000000000000..8be22479b41c
--- /dev/null
+++ b/drivers/input/touchscreen/cyttsp_core.c
@@ -0,0 +1,625 @@
+/*
+ * Core Source for:
+ * Cypress TrueTouch(TM) Standard Product (TTSP) touchscreen drivers.
+ * For use with Cypress Txx3xx parts.
+ * Supported parts include:
+ * CY8CTST341
+ * CY8CTMA340
+ *
+ * Copyright (C) 2009, 2010, 2011 Cypress Semiconductor, Inc.
+ * Copyright (C) 2012 Javier Martinez Canillas <javier@dowhile0.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2, and only version 2, as published by the
+ * Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Contact Cypress Semiconductor at www.cypress.com <kev@cypress.com>
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+
+#include "cyttsp_core.h"
+
+/* Bootloader number of command keys */
+#define CY_NUM_BL_KEYS          8
+
+/* helpers */
+#define GET_NUM_TOUCHES(x)              ((x) & 0x0F)
+#define IS_LARGE_AREA(x)                (((x) & 0x10) >> 4)
+#define IS_BAD_PKT(x)                   ((x) & 0x20)
+#define IS_VALID_APP(x)                 ((x) & 0x01)
+#define IS_OPERATIONAL_ERR(x)           ((x) & 0x3F)
+#define GET_HSTMODE(reg)                (((reg) & 0x70) >> 4)
+#define GET_BOOTLOADERMODE(reg)         (((reg) & 0x10) >> 4)
+
+#define CY_REG_BASE                     0x00
+#define CY_REG_ACT_DIST                 0x1E
+#define CY_REG_ACT_INTRVL               0x1D
+#define CY_REG_TCH_TMOUT                (CY_REG_ACT_INTRVL + 1)
+#define CY_REG_LP_INTRVL                (CY_REG_TCH_TMOUT + 1)
+#define CY_MAXZ                         255
+#define CY_DELAY_DFLT                   20 /* ms */
+#define CY_DELAY_MAX                    500
+#define CY_ACT_DIST_DFLT                0xF8
+#define CY_HNDSHK_BIT                   0x80
+/* device mode bits */
+#define CY_OPERATE_MODE                 0x00
+#define CY_SYSINFO_MODE                 0x10
+/* power mode select bits */
+#define CY_SOFT_RESET_MODE              0x01 /* return to Bootloader mode */
+#define CY_DEEP_SLEEP_MODE              0x02
+#define CY_LOW_POWER_MODE               0x04
+
+/* Slots management */
+#define CY_MAX_FINGER                   4
+#define CY_MAX_ID                       16
+
+static const u8 bl_command[] = {
+        0x00,                   /* file offset */
+        0xFF,                   /* command */
+        0xA5,                   /* exit bootloader command */
+        0, 1, 2, 3, 4, 5, 6, 7  /* default keys */
+};
+
+static int ttsp_read_block_data(struct cyttsp *ts, u8 command,
+                                u8 length, void *buf)
+{
+        int error;
+        int tries;
+
+        for (tries = 0; tries < CY_NUM_RETRY; tries++) {
+                error = ts->bus_ops->read(ts, command, length, buf);
+                if (!error)
+                        return 0;
+
+                msleep(CY_DELAY_DFLT);
+        }
+
+        return -EIO;
+}
+
+static int ttsp_write_block_data(struct cyttsp *ts, u8 command,
+                                 u8 length, void *buf)
+{
+        int error;
+        int tries;
+
+        for (tries = 0; tries < CY_NUM_RETRY; tries++) {
+                error = ts->bus_ops->write(ts, command, length, buf);
+                if (!error)
+                        return 0;
+
+                msleep(CY_DELAY_DFLT);
+        }
+
+        return -EIO;
+}
+
+static int ttsp_send_command(struct cyttsp *ts, u8 cmd)
+{
+        return ttsp_write_block_data(ts, CY_REG_BASE, sizeof(cmd), &cmd);
+}
+
+static int cyttsp_load_bl_regs(struct cyttsp *ts)
+{
+        memset(&ts->bl_data, 0, sizeof(ts->bl_data));
+        ts->bl_data.bl_status = 0x10;
+
+        return ttsp_read_block_data(ts, CY_REG_BASE,
+                                    sizeof(ts->bl_data), &ts->bl_data);
+}
+
+static int cyttsp_exit_bl_mode(struct cyttsp *ts)
+{
+        int error;
+        u8 bl_cmd[sizeof(bl_command)];
+
+        memcpy(bl_cmd, bl_command, sizeof(bl_command));
+        if (ts->pdata->bl_keys)
+                memcpy(&bl_cmd[sizeof(bl_command) - CY_NUM_BL_KEYS],
+                        ts->pdata->bl_keys, sizeof(bl_command));
+
+        error = ttsp_write_block_data(ts, CY_REG_BASE,
+                                      sizeof(bl_cmd), bl_cmd);
+        if (error)
+                return error;
+
+        /* wait for TTSP Device to complete the operation */
+        msleep(CY_DELAY_DFLT);
+
+        error = cyttsp_load_bl_regs(ts);
+        if (error)
+                return error;
+
+        if (GET_BOOTLOADERMODE(ts->bl_data.bl_status))
+                return -EIO;
+
+        return 0;
+}
+
+static int cyttsp_set_operational_mode(struct cyttsp *ts)
+{
+        int error;
+
+        error = ttsp_send_command(ts, CY_OPERATE_MODE);
+        if (error)
+                return error;
+
+        /* wait for TTSP Device to complete switch to Operational mode */
+        error = ttsp_read_block_data(ts, CY_REG_BASE,
+                                     sizeof(ts->xy_data), &ts->xy_data);
+        if (error)
+                return error;
+
+        return ts->xy_data.act_dist == CY_ACT_DIST_DFLT ? -EIO : 0;
+}
+
+static int cyttsp_set_sysinfo_mode(struct cyttsp *ts)
+{
+        int error;
+
+        memset(&ts->sysinfo_data, 0, sizeof(ts->sysinfo_data));
+
+        /* switch to sysinfo mode */
+        error = ttsp_send_command(ts, CY_SYSINFO_MODE);
+        if (error)
+                return error;
+
+        /* read sysinfo registers */
+        msleep(CY_DELAY_DFLT);
+        error = ttsp_read_block_data(ts, CY_REG_BASE, sizeof(ts->sysinfo_data),
+                                      &ts->sysinfo_data);
+        if (error)
+                return error;
+
+        if (!ts->sysinfo_data.tts_verh && !ts->sysinfo_data.tts_verl)
+                return -EIO;
+
+        return 0;
+}
+
+static int cyttsp_set_sysinfo_regs(struct cyttsp *ts)
+{
+        int retval = 0;
+
+        if (ts->pdata->act_intrvl != CY_ACT_INTRVL_DFLT ||
+            ts->pdata->tch_tmout != CY_TCH_TMOUT_DFLT ||
+            ts->pdata->lp_intrvl != CY_LP_INTRVL_DFLT) {
+
+                u8 intrvl_ray[] = {
+                        ts->pdata->act_intrvl,
+                        ts->pdata->tch_tmout,
+                        ts->pdata->lp_intrvl
+                };
+
+                /* set intrvl registers */
+                retval = ttsp_write_block_data(ts, CY_REG_ACT_INTRVL,
+                                        sizeof(intrvl_ray), intrvl_ray);
+                msleep(CY_DELAY_DFLT);
+        }
+
+        return retval;
+}
+
+static int cyttsp_soft_reset(struct cyttsp *ts)
+{
+        unsigned long timeout;
+        int retval;
+
+        /* wait for interrupt to set ready completion */
+        INIT_COMPLETION(ts->bl_ready);
+        ts->state = CY_BL_STATE;
+
+        enable_irq(ts->irq);
+
+        retval = ttsp_send_command(ts, CY_SOFT_RESET_MODE);
+        if (retval)
+                goto out;
+
+        timeout = wait_for_completion_timeout(&ts->bl_ready,
+                        msecs_to_jiffies(CY_DELAY_DFLT * CY_DELAY_MAX));
+        retval = timeout ? 0 : -EIO;
+
+out:
+        ts->state = CY_IDLE_STATE;
+        disable_irq(ts->irq);
+        return retval;
+}
+
+static int cyttsp_act_dist_setup(struct cyttsp *ts)
+{
+        u8 act_dist_setup = ts->pdata->act_dist;
+
+        /* Init gesture; active distance setup */
+        return ttsp_write_block_data(ts, CY_REG_ACT_DIST,
+                                sizeof(act_dist_setup), &act_dist_setup);
+}
+
+static void cyttsp_extract_track_ids(struct cyttsp_xydata *xy_data, int *ids)
+{
+        ids[0] = xy_data->touch12_id >> 4;
+        ids[1] = xy_data->touch12_id & 0xF;
+        ids[2] = xy_data->touch34_id >> 4;
+        ids[3] = xy_data->touch34_id & 0xF;
+}
+
+static const struct cyttsp_tch *cyttsp_get_tch(struct cyttsp_xydata *xy_data,
+                                               int idx)
+{
+        switch (idx) {
+        case 0:
+                return &xy_data->tch1;
+        case 1:
+                return &xy_data->tch2;
+        case 2:
+                return &xy_data->tch3;
+        case 3:
+                return &xy_data->tch4;
+        default:
+                return NULL;
+        }
+}
+
+static void cyttsp_report_tchdata(struct cyttsp *ts)
+{
+        struct cyttsp_xydata *xy_data = &ts->xy_data;
+        struct input_dev *input = ts->input;
+        int num_tch = GET_NUM_TOUCHES(xy_data->tt_stat);
+        const struct cyttsp_tch *tch;
+        int ids[CY_MAX_ID];
+        int i;
+        DECLARE_BITMAP(used, CY_MAX_ID);
+
+        if (IS_LARGE_AREA(xy_data->tt_stat) == 1) {
+                /* terminate all active tracks */
+                num_tch = 0;
+                dev_dbg(ts->dev, "%s: Large area detected\n", __func__);
+        } else if (num_tch > CY_MAX_FINGER) {
+                /* terminate all active tracks */
+                num_tch = 0;
+                dev_dbg(ts->dev, "%s: Num touch error detected\n", __func__);
+        } else if (IS_BAD_PKT(xy_data->tt_mode)) {
+                /* terminate all active tracks */
+                num_tch = 0;
+                dev_dbg(ts->dev, "%s: Invalid buffer detected\n", __func__);
+        }
+
+        cyttsp_extract_track_ids(xy_data, ids);
+
+        bitmap_zero(used, CY_MAX_ID);
+
+        for (i = 0; i < num_tch; i++) {
+                tch = cyttsp_get_tch(xy_data, i);
+
+                input_mt_slot(input, ids[i]);
+                input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
+                input_report_abs(input, ABS_MT_POSITION_X, be16_to_cpu(tch->x));
+                input_report_abs(input, ABS_MT_POSITION_Y, be16_to_cpu(tch->y));
+                input_report_abs(input, ABS_MT_TOUCH_MAJOR, tch->z);
+
+                __set_bit(ids[i], used);
+        }
+
+        for (i = 0; i < CY_MAX_ID; i++) {
+                if (test_bit(i, used))
+                        continue;
+
+                input_mt_slot(input, i);
+                input_mt_report_slot_state(input, MT_TOOL_FINGER, false);
+        }
+
+        input_sync(input);
+}
+
+static irqreturn_t cyttsp_irq(int irq, void *handle)
+{
+        struct cyttsp *ts = handle;
+        int error;
+
+        if (unlikely(ts->state == CY_BL_STATE)) {
+                complete(&ts->bl_ready);
+                goto out;
+        }
+
+        /* Get touch data from CYTTSP device */
+        error = ttsp_read_block_data(ts, CY_REG_BASE,
+                                 sizeof(struct cyttsp_xydata), &ts->xy_data);
+        if (error)
+                goto out;
+
+        /* provide flow control handshake */
+        if (ts->pdata->use_hndshk) {
+                error = ttsp_send_command(ts,
+                                ts->xy_data.hst_mode ^ CY_HNDSHK_BIT);
+                if (error)
+                        goto out;
+        }
+
+        if (unlikely(ts->state == CY_IDLE_STATE))
+                goto out;
+
+        if (GET_BOOTLOADERMODE(ts->xy_data.tt_mode)) {
+                /*
+                 * TTSP device has reset back to bootloader mode.
+                 * Restore to operational mode.
+                 */
+                error = cyttsp_exit_bl_mode(ts);
+                if (error) {
+                        dev_err(ts->dev,
+                                "Could not return to operational mode, err: %d\n",
+                                error);
+                        ts->state = CY_IDLE_STATE;
+                }
+        } else {
+                cyttsp_report_tchdata(ts);
+        }
+
+out:
+        return IRQ_HANDLED;
+}
+
+static int cyttsp_power_on(struct cyttsp *ts)
+{
+        int error;
+
+        error = cyttsp_soft_reset(ts);
+        if (error)
+                return error;
+
+        error = cyttsp_load_bl_regs(ts);
+        if (error)
+                return error;
+
+        if (GET_BOOTLOADERMODE(ts->bl_data.bl_status) &&
+            IS_VALID_APP(ts->bl_data.bl_status)) {
+                error = cyttsp_exit_bl_mode(ts);
+                if (error)
+                        return error;
+        }
+
+        if (GET_HSTMODE(ts->bl_data.bl_file) != CY_OPERATE_MODE ||
+            IS_OPERATIONAL_ERR(ts->bl_data.bl_status)) {
+                return -ENODEV;
+        }
+
+        error = cyttsp_set_sysinfo_mode(ts);
+        if (error)
+                return error;
+
+        error = cyttsp_set_sysinfo_regs(ts);
+        if (error)
+                return error;
+
+        error = cyttsp_set_operational_mode(ts);
+        if (error)
+                return error;
+
+        /* init active distance */
+        error = cyttsp_act_dist_setup(ts);
+        if (error)
+                return error;
+
+        ts->state = CY_ACTIVE_STATE;
+
+        return 0;
+}
+
+static int cyttsp_enable(struct cyttsp *ts)
+{
+        int error;
+
+        /*
+         * The device firmware can wake on an I2C or SPI memory slave
+         * address match. So just reading a register is sufficient to
+         * wake up the device. The first read attempt will fail but it
+         * will wake it up making the second read attempt successful.
+         */
+        error = ttsp_read_block_data(ts, CY_REG_BASE,
+                                     sizeof(ts->xy_data), &ts->xy_data);
+        if (error)
+                return error;
+
+        if (GET_HSTMODE(ts->xy_data.hst_mode))
+                return -EIO;
+
+        enable_irq(ts->irq);
+
+        return 0;
+}
+
+static int cyttsp_disable(struct cyttsp *ts)
+{
+        int error;
+
+        error = ttsp_send_command(ts, CY_LOW_POWER_MODE);
+        if (error)
+                return error;
+
+        disable_irq(ts->irq);
+
+        return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int cyttsp_suspend(struct device *dev)
+{
+        struct cyttsp *ts = dev_get_drvdata(dev);
+        int retval = 0;
+
+        mutex_lock(&ts->input->mutex);
+
+        if (ts->input->users) {
+                retval = cyttsp_disable(ts);
+                if (retval == 0)
+                        ts->suspended = true;
+        }
+
+        mutex_unlock(&ts->input->mutex);
+
+        return retval;
+}
+
+static int cyttsp_resume(struct device *dev)
+{
+        struct cyttsp *ts = dev_get_drvdata(dev);
+
+        mutex_lock(&ts->input->mutex);
+
+        if (ts->input->users)
+                cyttsp_enable(ts);
+
+        ts->suspended = false;
+
+        mutex_unlock(&ts->input->mutex);
+
+        return 0;
+}
+
+#endif
+
+SIMPLE_DEV_PM_OPS(cyttsp_pm_ops, cyttsp_suspend, cyttsp_resume);
+EXPORT_SYMBOL_GPL(cyttsp_pm_ops);
+
+static int cyttsp_open(struct input_dev *dev)
+{
+        struct cyttsp *ts = input_get_drvdata(dev);
+        int retval = 0;
+
+        if (!ts->suspended)
+                retval = cyttsp_enable(ts);
+
+        return retval;
+}
+
+static void cyttsp_close(struct input_dev *dev)
+{
+        struct cyttsp *ts = input_get_drvdata(dev);
+
+        if (!ts->suspended)
+                cyttsp_disable(ts);
+}
+
+struct cyttsp *cyttsp_probe(const struct cyttsp_bus_ops *bus_ops,
+                            struct device *dev, int irq, size_t xfer_buf_size)
+{
+        const struct cyttsp_platform_data *pdata = dev->platform_data;
+        struct cyttsp *ts;
+        struct input_dev *input_dev;
+        int error;
+
+        if (!dev || !bus_ops || !pdata || !pdata->name || irq <= 0) {
+                error = -EINVAL;
+                goto err_out;
+        }
+
+        ts = kzalloc(sizeof(*ts) + xfer_buf_size, GFP_KERNEL);
+        input_dev = input_allocate_device();
+        if (!ts || !input_dev) {
+                error = -ENOMEM;
+                goto err_free_mem;
+        }
+
+        ts->dev = dev;
+        ts->input = input_dev;
+        ts->pdata = dev->platform_data;
+        ts->bus_ops = bus_ops;
+        ts->irq = irq;
+
+        init_completion(&ts->bl_ready);
+        snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
+
+        if (pdata->init) {
+                error = pdata->init();
+                if (error) {
+                        dev_err(ts->dev, "platform init failed, err: %d\n",
+                                error);
+                        goto err_free_mem;
+                }
+        }
+
+        input_dev->name = pdata->name;
+        input_dev->phys = ts->phys;
+        input_dev->id.bustype = bus_ops->bustype;
+        input_dev->dev.parent = ts->dev;
+
+        input_dev->open = cyttsp_open;
+        input_dev->close = cyttsp_close;
+
+        input_set_drvdata(input_dev, ts);
+
+        __set_bit(EV_ABS, input_dev->evbit);
+        input_set_abs_params(input_dev, ABS_MT_POSITION_X,
+                             0, pdata->maxx, 0, 0);
+        input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
+                             0, pdata->maxy, 0, 0);
+        input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
+                             0, CY_MAXZ, 0, 0);
+
+        input_mt_init_slots(input_dev, CY_MAX_ID);
+
+        error = request_threaded_irq(ts->irq, NULL, cyttsp_irq,
+                                     IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+                                     pdata->name, ts);
+        if (error) {
+                dev_err(ts->dev, "failed to request IRQ %d, err: %d\n",
+                        ts->irq, error);
+                goto err_platform_exit;
+        }
+
+        disable_irq(ts->irq);
+
+        error = cyttsp_power_on(ts);
+        if (error)
+                goto err_free_irq;
+
+        error = input_register_device(input_dev);
+        if (error) {
+                dev_err(ts->dev, "failed to register input device: %d\n",
+                        error);
+                goto err_free_irq;
+        }
+
+        return ts;
+
+err_free_irq:
+        free_irq(ts->irq, ts);
+err_platform_exit:
+        if (pdata->exit)
+                pdata->exit();
+err_free_mem:
+        input_free_device(input_dev);
+        kfree(ts);
+err_out:
+        return ERR_PTR(error);
+}
+EXPORT_SYMBOL_GPL(cyttsp_probe);
+
+void cyttsp_remove(struct cyttsp *ts)
+{
+        free_irq(ts->irq, ts);
+        input_unregister_device(ts->input);
+        if (ts->pdata->exit)
+                ts->pdata->exit();
+        kfree(ts);
+}
+EXPORT_SYMBOL_GPL(cyttsp_remove);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard touchscreen driver core");
+MODULE_AUTHOR("Cypress");