Input: add driver for SiS 9200 family I2C touchscreen controllers
authorMika Penttilä <mika.penttila@nextfour.com>
Wed, 3 Aug 2016 06:52:32 +0000 (23:52 -0700)
committerDmitry Torokhov <dmitry.torokhov@gmail.com>
Wed, 3 Aug 2016 07:49:00 +0000 (00:49 -0700)
This is a driver for SiS 9200 family touchscreen controllers using I2C bus.

Signed-off-by: Mika Penttilä <mika.penttila@nextfour.com>
Acked-by: Tammy Tseng <tammy_tseng@sis.com>
Acked-by: Yuger Yu <yuger_yu@sis.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Documentation/devicetree/bindings/input/touchscreen/sis_i2c.txt [new file with mode: 0644]
Documentation/devicetree/bindings/vendor-prefixes.txt
drivers/input/touchscreen/Kconfig
drivers/input/touchscreen/Makefile
drivers/input/touchscreen/sis_i2c.c [new file with mode: 0644]

diff --git a/Documentation/devicetree/bindings/input/touchscreen/sis_i2c.txt b/Documentation/devicetree/bindings/input/touchscreen/sis_i2c.txt
new file mode 100644 (file)
index 0000000..d87ad14
--- /dev/null
@@ -0,0 +1,33 @@
+* SiS I2C Multiple Touch Controller
+
+Required properties:
+- compatible: must be "sis,9200-ts"
+- reg: i2c slave address
+- interrupt-parent: the phandle for the interrupt controller
+  (see interrupt binding [0])
+- interrupts: touch controller interrupt (see interrupt
+  binding [0])
+
+Optional properties:
+- pinctrl-names: should be "default" (see pinctrl binding [1]).
+- pinctrl-0: a phandle pointing to the pin settings for the
+  device (see pinctrl binding [1]).
+- attn-gpios: the gpio pin used as attention line
+- reset-gpios: the gpio pin used to reset the controller
+- wakeup-source: touchscreen can be used as a wakeup source
+
+[0]: Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+[1]: Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
+
+Example:
+
+       sis9255@5c  {
+               compatible = "sis,9200-ts";
+               reg = <0x5c>;
+               pinctrl-names = "default";
+               pinctrl-0 = <&pinctrl_sis>;
+               interrupt-parent = <&gpio3>;
+               interrupts = <19 IRQ_TYPE_EDGE_FALLING>;
+               irq-gpios = <&gpio3 19 GPIO_ACTIVE_LOW>;
+               reset-gpios = <&gpio2 30 GPIO_ACTIVE_LOW>;
+       };
index 80fdbe2ce088c5018b91af9ccd546fde19e8e221..99029cfed45932918a1c710b192996f22fb6769f 100644 (file)
@@ -221,6 +221,7 @@ simtek
 sii    Seiko Instruments, Inc.
 silergy        Silergy Corp.
 sirf   SiRF Technology, Inc.
+sis    Silicon Integrated Systems Corp.
 sitronix       Sitronix Technology Corporation
 skyworks       Skyworks Solutions, Inc.
 smsc   Standard Microsystems Corporation
index 6abcd176609244026dc23a1bfb9ecf33f22186e7..8d893cefb0e3186addeec50aa25be98ff8ad2e8a 100644 (file)
@@ -1071,6 +1071,18 @@ config TOUCHSCREEN_SILEAD
          To compile this driver as a module, choose M here: the
          module will be called silead.
 
+config TOUCHSCREEN_SIS_I2C
+       tristate "SiS 9200 family I2C touchscreen"
+       depends on I2C
+       depends on GPIOLIB || COMPILE_TEST
+       help
+         This enables support for SiS 9200 family over I2C based touchscreens.
+
+         If unsure, say N.
+
+         To compile this driver as a module, choose M here: the
+         module will be called sis_i2c.
+
 config TOUCHSCREEN_ST1232
        tristate "Sitronix ST1232 touchscreen controllers"
        depends on I2C
index 3b598c90167773fff7969272af6071729e8f1205..b4373d6be4021687c1f4fc4b4bc0faa054141ec0 100644 (file)
@@ -65,6 +65,7 @@ obj-$(CONFIG_TOUCHSCREEN_PIXCIR)      += pixcir_i2c_ts.o
 obj-$(CONFIG_TOUCHSCREEN_RM_TS)                += raydium_i2c_ts.o
 obj-$(CONFIG_TOUCHSCREEN_S3C2410)      += s3c2410_ts.o
 obj-$(CONFIG_TOUCHSCREEN_SILEAD)       += silead.o
+obj-$(CONFIG_TOUCHSCREEN_SIS_I2C)      += sis_i2c.o
 obj-$(CONFIG_TOUCHSCREEN_ST1232)       += st1232.o
 obj-$(CONFIG_TOUCHSCREEN_STMPE)                += stmpe-ts.o
 obj-$(CONFIG_TOUCHSCREEN_SUN4I)                += sun4i-ts.o
diff --git a/drivers/input/touchscreen/sis_i2c.c b/drivers/input/touchscreen/sis_i2c.c
new file mode 100644 (file)
index 0000000..8d93f8c
--- /dev/null
@@ -0,0 +1,413 @@
+/*
+ * Touch Screen driver for SiS 9200 family I2C Touch panels
+ *
+ * Copyright (C) 2015 SiS, Inc.
+ * Copyright (C) 2016 Nextfour Group
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ */
+
+#include <linux/crc-itu-t.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/interrupt.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <asm/unaligned.h>
+
+#define SIS_I2C_NAME           "sis_i2c_ts"
+
+/*
+ * The I2C packet format:
+ * le16                byte count
+ * u8          Report ID
+ * <contact data - variable length>
+ * u8          Number of contacts
+ * le16                Scan Time (optional)
+ * le16                CRC
+ *
+ * One touch point information consists of 6+ bytes, the order is:
+ * u8          contact state
+ * u8          finger id
+ * le16                x axis
+ * le16                y axis
+ * u8          contact width (optional)
+ * u8          contact height (optional)
+ * u8          pressure (optional)
+ *
+ * Maximum amount of data transmitted in one shot is 64 bytes, if controller
+ * needs to report more contacts than fit in one packet it will send true
+ * number of contacts in first packet and 0 as number of contacts in second
+ * packet.
+ */
+
+#define SIS_MAX_PACKET_SIZE            64
+
+#define SIS_PKT_LEN_OFFSET             0
+#define SIS_PKT_REPORT_OFFSET          2 /* Report ID/type */
+#define SIS_PKT_CONTACT_OFFSET         3 /* First contact */
+
+#define SIS_SCAN_TIME_LEN              2
+
+/* Supported report types */
+#define SIS_ALL_IN_ONE_PACKAGE         0x10
+#define SIS_PKT_IS_TOUCH(x)            (((x) & 0x0f) == 0x01)
+#define SIS_PKT_IS_HIDI2C(x)           (((x) & 0x0f) == 0x06)
+
+/* Contact properties within report */
+#define SIS_PKT_HAS_AREA(x)            ((x) & BIT(4))
+#define SIS_PKT_HAS_PRESSURE(x)                ((x) & BIT(5))
+#define SIS_PKT_HAS_SCANTIME(x)                ((x) & BIT(6))
+
+/* Contact size */
+#define SIS_BASE_LEN_PER_CONTACT       6
+#define SIS_AREA_LEN_PER_CONTACT       2
+#define SIS_PRESSURE_LEN_PER_CONTACT   1
+
+/* Offsets within contact data */
+#define SIS_CONTACT_STATUS_OFFSET      0
+#define SIS_CONTACT_ID_OFFSET          1 /* Contact ID */
+#define SIS_CONTACT_X_OFFSET           2
+#define SIS_CONTACT_Y_OFFSET           4
+#define SIS_CONTACT_WIDTH_OFFSET       6
+#define SIS_CONTACT_HEIGHT_OFFSET      7
+#define SIS_CONTACT_PRESSURE_OFFSET(id)        (SIS_PKT_HAS_AREA(id) ? 8 : 6)
+
+/* Individual contact state */
+#define SIS_STATUS_UP                  0x0
+#define SIS_STATUS_DOWN                        0x3
+
+/* Touchscreen parameters */
+#define SIS_MAX_FINGERS                        10
+#define SIS_MAX_X                      4095
+#define SIS_MAX_Y                      4095
+#define SIS_MAX_PRESSURE               255
+
+/* Resolution diagonal */
+#define SIS_AREA_LENGTH_LONGER         5792
+/*((SIS_MAX_X^2) + (SIS_MAX_Y^2))^0.5*/
+#define SIS_AREA_LENGTH_SHORT          5792
+#define SIS_AREA_UNIT                  (5792 / 32)
+
+struct sis_ts_data {
+       struct i2c_client *client;
+       struct input_dev *input;
+
+       struct gpio_desc *attn_gpio;
+       struct gpio_desc *reset_gpio;
+
+       u8 packet[SIS_MAX_PACKET_SIZE];
+};
+
+static int sis_read_packet(struct i2c_client *client, u8 *buf,
+                          unsigned int *num_contacts,
+                          unsigned int *contact_size)
+{
+       int count_idx;
+       int ret;
+       u16 len;
+       u16 crc, pkg_crc;
+       u8 report_id;
+
+       ret = i2c_master_recv(client, buf, SIS_MAX_PACKET_SIZE);
+       if (ret <= 0)
+               return -EIO;
+
+       len = get_unaligned_le16(&buf[SIS_PKT_LEN_OFFSET]);
+       if (len > SIS_MAX_PACKET_SIZE) {
+               dev_err(&client->dev,
+                       "%s: invalid packet length (%d vs %d)\n",
+                       __func__, len, SIS_MAX_PACKET_SIZE);
+               return -E2BIG;
+       }
+
+       if (len < 10)
+               return -EINVAL;
+
+       report_id = buf[SIS_PKT_REPORT_OFFSET];
+       count_idx  = len - 1;
+       *contact_size = SIS_BASE_LEN_PER_CONTACT;
+
+       if (report_id != SIS_ALL_IN_ONE_PACKAGE) {
+               if (SIS_PKT_IS_TOUCH(report_id)) {
+                       /*
+                        * Calculate CRC ignoring packet length
+                        * in the beginning and CRC transmitted
+                        * at the end of the packet.
+                        */
+                       crc = crc_itu_t(0, buf + 2, len - 2 - 2);
+                       pkg_crc = get_unaligned_le16(&buf[len - 2]);
+
+                       if (crc != pkg_crc) {
+                               dev_err(&client->dev,
+                                       "%s: CRC Error (%d vs %d)\n",
+                                       __func__, crc, pkg_crc);
+                               return -EINVAL;
+                       }
+
+                       count_idx -= 2;
+
+               } else if (!SIS_PKT_IS_HIDI2C(report_id)) {
+                       dev_err(&client->dev,
+                               "%s: invalid packet ID %#02x\n",
+                               __func__, report_id);
+                       return -EINVAL;
+               }
+
+               if (SIS_PKT_HAS_SCANTIME(report_id))
+                       count_idx -= SIS_SCAN_TIME_LEN;
+
+               if (SIS_PKT_HAS_AREA(report_id))
+                       *contact_size += SIS_AREA_LEN_PER_CONTACT;
+               if (SIS_PKT_HAS_PRESSURE(report_id))
+                       *contact_size += SIS_PRESSURE_LEN_PER_CONTACT;
+       }
+
+       *num_contacts = buf[count_idx];
+       return 0;
+}
+
+static int sis_ts_report_contact(struct sis_ts_data *ts, const u8 *data, u8 id)
+{
+       struct input_dev *input = ts->input;
+       int slot;
+       u8 status = data[SIS_CONTACT_STATUS_OFFSET];
+       u8 pressure;
+       u8 height, width;
+       u16 x, y;
+
+       if (status != SIS_STATUS_DOWN && status != SIS_STATUS_UP) {
+               dev_err(&ts->client->dev, "Unexpected touch status: %#02x\n",
+                       data[SIS_CONTACT_STATUS_OFFSET]);
+               return -EINVAL;
+       }
+
+       slot = input_mt_get_slot_by_key(input, data[SIS_CONTACT_ID_OFFSET]);
+       if (slot < 0)
+               return -ENOENT;
+
+       input_mt_slot(input, slot);
+       input_mt_report_slot_state(input, MT_TOOL_FINGER,
+                                  status == SIS_STATUS_DOWN);
+
+       if (status == SIS_STATUS_DOWN) {
+               pressure = height = width = 1;
+               if (id != SIS_ALL_IN_ONE_PACKAGE) {
+                       if (SIS_PKT_HAS_AREA(id)) {
+                               width = data[SIS_CONTACT_WIDTH_OFFSET];
+                               height = data[SIS_CONTACT_HEIGHT_OFFSET];
+                       }
+
+                       if (SIS_PKT_HAS_PRESSURE(id))
+                               pressure =
+                                       data[SIS_CONTACT_PRESSURE_OFFSET(id)];
+               }
+
+               x = get_unaligned_le16(&data[SIS_CONTACT_X_OFFSET]);
+               y = get_unaligned_le16(&data[SIS_CONTACT_Y_OFFSET]);
+
+               input_report_abs(input, ABS_MT_TOUCH_MAJOR,
+                                width * SIS_AREA_UNIT);
+               input_report_abs(input, ABS_MT_TOUCH_MINOR,
+                                height * SIS_AREA_UNIT);
+               input_report_abs(input, ABS_MT_PRESSURE, pressure);
+               input_report_abs(input, ABS_MT_POSITION_X, x);
+               input_report_abs(input, ABS_MT_POSITION_Y, y);
+       }
+
+       return 0;
+}
+
+static void sis_ts_handle_packet(struct sis_ts_data *ts)
+{
+       const u8 *contact;
+       unsigned int num_to_report = 0;
+       unsigned int num_contacts;
+       unsigned int num_reported;
+       unsigned int contact_size;
+       int error;
+       u8 report_id;
+
+       do {
+               error = sis_read_packet(ts->client, ts->packet,
+                                       &num_contacts, &contact_size);
+               if (error)
+                       break;
+
+               if (num_to_report == 0) {
+                       num_to_report = num_contacts;
+               } else if (num_contacts != 0) {
+                       dev_err(&ts->client->dev,
+                               "%s: nonzero (%d) point count in tail packet\n",
+                               __func__, num_contacts);
+                       break;
+               }
+
+               report_id = ts->packet[SIS_PKT_REPORT_OFFSET];
+               contact = &ts->packet[SIS_PKT_CONTACT_OFFSET];
+               num_reported = 0;
+
+               while (num_to_report > 0) {
+                       error = sis_ts_report_contact(ts, contact, report_id);
+                       if (error)
+                               break;
+
+                       contact += contact_size;
+                       num_to_report--;
+                       num_reported++;
+
+                       if (report_id != SIS_ALL_IN_ONE_PACKAGE &&
+                           num_reported >= 5) {
+                               /*
+                                * The remainder of contacts is sent
+                                * in the 2nd packet.
+                                */
+                               break;
+                       }
+               }
+       } while (num_to_report > 0);
+
+       input_mt_sync_frame(ts->input);
+       input_sync(ts->input);
+}
+
+static irqreturn_t sis_ts_irq_handler(int irq, void *dev_id)
+{
+       struct sis_ts_data *ts = dev_id;
+
+       do {
+               sis_ts_handle_packet(ts);
+       } while (ts->attn_gpio && gpiod_get_value_cansleep(ts->attn_gpio));
+
+       return IRQ_HANDLED;
+}
+
+static void sis_ts_reset(struct sis_ts_data *ts)
+{
+       if (ts->reset_gpio) {
+               /* Get out of reset */
+               usleep_range(1000, 2000);
+               gpiod_set_value(ts->reset_gpio, 1);
+               usleep_range(1000, 2000);
+               gpiod_set_value(ts->reset_gpio, 0);
+               msleep(100);
+       }
+}
+
+static int sis_ts_probe(struct i2c_client *client,
+                       const struct i2c_device_id *id)
+{
+       struct sis_ts_data *ts;
+       struct input_dev *input;
+       int error;
+
+       ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
+       if (!ts)
+               return -ENOMEM;
+
+       ts->client = client;
+       i2c_set_clientdata(client, ts);
+
+       ts->attn_gpio = devm_gpiod_get_optional(&client->dev,
+                                               "attn", GPIOD_IN);
+       if (IS_ERR(ts->attn_gpio)) {
+               error = PTR_ERR(ts->attn_gpio);
+               if (error != -EPROBE_DEFER)
+                       dev_err(&client->dev,
+                               "Failed to get attention GPIO: %d\n", error);
+               return error;
+       }
+
+       ts->reset_gpio = devm_gpiod_get_optional(&client->dev,
+                                                "reset", GPIOD_OUT_LOW);
+       if (IS_ERR(ts->reset_gpio)) {
+               error = PTR_ERR(ts->reset_gpio);
+               if (error != -EPROBE_DEFER)
+                       dev_err(&client->dev,
+                               "Failed to get reset GPIO: %d\n", error);
+               return error;
+       }
+
+       sis_ts_reset(ts);
+
+       ts->input = input = devm_input_allocate_device(&client->dev);
+       if (!input) {
+               dev_err(&client->dev, "Failed to allocate input device\n");
+               return -ENOMEM;
+       }
+
+       input->name = "SiS Touchscreen";
+       input->id.bustype = BUS_I2C;
+
+       input_set_abs_params(input, ABS_MT_POSITION_X, 0, SIS_MAX_X, 0, 0);
+       input_set_abs_params(input, ABS_MT_POSITION_Y, 0, SIS_MAX_Y, 0, 0);
+       input_set_abs_params(input, ABS_MT_PRESSURE, 0, SIS_MAX_PRESSURE, 0, 0);
+       input_set_abs_params(input, ABS_MT_TOUCH_MAJOR,
+                            0, SIS_AREA_LENGTH_LONGER, 0, 0);
+       input_set_abs_params(input, ABS_MT_TOUCH_MINOR,
+                            0, SIS_AREA_LENGTH_SHORT, 0, 0);
+
+       error = input_mt_init_slots(input, SIS_MAX_FINGERS, INPUT_MT_DIRECT);
+       if (error) {
+               dev_err(&client->dev,
+                       "Failed to initialize MT slots: %d\n", error);
+               return error;
+       }
+
+       error = devm_request_threaded_irq(&client->dev, client->irq,
+                                         NULL, sis_ts_irq_handler,
+                                         IRQF_ONESHOT,
+                                         client->name, ts);
+       if (error) {
+               dev_err(&client->dev, "Failed to request IRQ: %d\n", error);
+               return error;
+       }
+
+       error = input_register_device(ts->input);
+       if (error) {
+               dev_err(&client->dev,
+                       "Failed to register input device: %d\n", error);
+               return error;
+       }
+
+       return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id sis_ts_dt_ids[] = {
+       { .compatible = "sis,9200-ts" },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sis_ts_dt_ids);
+#endif
+
+static const struct i2c_device_id sis_ts_id[] = {
+       { SIS_I2C_NAME, 0 },
+       { "9200-ts",    0 },
+       { /* sentinel */  }
+};
+MODULE_DEVICE_TABLE(i2c, sis_ts_id);
+
+static struct i2c_driver sis_ts_driver = {
+       .driver = {
+               .name   = SIS_I2C_NAME,
+               .of_match_table = of_match_ptr(sis_ts_dt_ids),
+       },
+       .probe          = sis_ts_probe,
+       .id_table       = sis_ts_id,
+};
+module_i2c_driver(sis_ts_driver);
+
+MODULE_DESCRIPTION("SiS 9200 Family Touchscreen Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Mika Penttilä <mika.penttila@nextfour.com>");