[PATCH v5 1/2] Input: Driver for SiS 9200 family I2C touchscreen controller.

From: mika.penttila
Date: Fri May 06 2016 - 01:23:13 EST


From: Mika Penttilà <mika.penttila@xxxxxxxxxxxx>

Multitouch protocol B support.

v5:
- rebased to 4.6.0-rc6

v4:
- cleanups and fixes according to review feedback
- irq and reset gpios are now optional,
if not spesified it is expected the firmware / hw
takes care of reset states and irq flow
- irq and reset gpio polarities come from dts/firmware
- report parsing and reporting are done at once
- error handling improvements
- misc cleanups
- added comments

v3:
- cleanup unused defines
- added acked-bys from SiS

v2:
- use gpio descriptor api
- probe cleanups
- error handling cleanups

Signed-off-by: Mika Penttilà <mika.penttila@xxxxxxxxxxxx>
Acked-by: Tammy Tseng <tammy_tseng@xxxxxxx>
Acked-by: Yuger Yu <yuger_yu@xxxxxxx>
---
drivers/input/touchscreen/Kconfig | 12 +
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/sis_i2c.c | 461 ++++++++++++++++++++++++++++++++++++
3 files changed, 474 insertions(+)
create mode 100644 drivers/input/touchscreen/sis_i2c.c

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 8ecdc38..8f06ae7 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -1155,4 +1155,16 @@ config TOUCHSCREEN_ROHM_BU21023
To compile this driver as a module, choose M here: the
module will be called bu21023_ts.

+config TOUCHSCREEN_SIS_I2C
+ tristate "SiS 9200 family I2C touchscreen driver"
+ depends on I2C
+ depends on GPIOLIB
+ 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.
+
endif
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index f42975e..0839e99 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -63,6 +63,7 @@ obj-$(CONFIG_TOUCHSCREEN_PCAP) += pcap_ts.o
obj-$(CONFIG_TOUCHSCREEN_PENMOUNT) += penmount.o
obj-$(CONFIG_TOUCHSCREEN_PIXCIR) += pixcir_i2c_ts.o
obj-$(CONFIG_TOUCHSCREEN_S3C2410) += s3c2410_ts.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
index 0000000..f1b66fa
--- /dev/null
+++ b/drivers/input/touchscreen/sis_i2c.c
@@ -0,0 +1,461 @@
+/* drivers/input/touchscreen/sis_i2c.c
+ * - I2C Touch panel driver for SiS 9200 family
+ *
+ * Copyright (C) 2011 SiS, Inc.
+ * Copyright (C) 2015 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/module.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/linkage.h>
+#include <linux/slab.h>
+#include <linux/of_gpio.h>
+#include <linux/uaccess.h>
+#include <linux/irq.h>
+#include <asm/unaligned.h>
+#include <linux/crc-itu-t.h>
+
+#define SIS_I2C_NAME "sis_i2c_ts"
+#define MAX_FINGERS 10
+
+#define SIS_MAX_X 4095
+#define SIS_MAX_Y 4095
+
+#define PACKET_BUFFER_SIZE 128
+
+#define SIS_CMD_NORMAL 0x0
+
+#define TOUCHDOWN 0x3
+#define TOUCHUP 0x0
+#define MAX_BYTE 64
+#define PRESSURE_MAX 255
+
+/* Resolution diagonal */
+#define AREA_LENGTH_LONGER 5792
+/*((SIS_MAX_X^2) + (SIS_MAX_Y^2))^0.5*/
+#define AREA_LENGTH_SHORT 5792
+#define AREA_UNIT (5792/32)
+
+#define P_BYTECOUNT 0
+#define ALL_IN_ONE_PACKAGE 0x10
+#define IS_TOUCH(x) ((x) & 0x1)
+#define IS_HIDI2C(x) (((x) & 0xF) == 0x06)
+#define IS_AREA(x) (((x) >> 4) & 0x1)
+#define IS_PRESSURE(x) (((x) >> 5) & 0x1)
+#define IS_SCANTIME(x) (((x) >> 6) & 0x1)
+
+#define NORMAL_LEN_PER_POINT 6
+#define AREA_LEN_PER_POINT 2
+#define PRESSURE_LEN_PER_POINT 1
+
+#define TOUCH_FORMAT 0x1
+#define HIDI2C_FORMAT 0x6
+#define P_REPORT_ID 2
+#define BYTE_BYTECOUNT 2
+#define BYTE_REPORTID 1
+#define BYTE_CRC_HIDI2C 0
+#define BYTE_CRC_I2C 2
+#define BYTE_SCANTIME 2
+
+struct _touchpoint {
+ u8 id;
+ u16 x, y;
+ u16 pressure;
+ u16 width;
+ u16 height;
+};
+
+struct sistp_driver_data {
+ int fingers;
+ struct _touchpoint pt[MAX_FINGERS];
+};
+
+struct sis_ts_data {
+ struct gpio_desc *irq_gpiod;
+ struct gpio_desc *reset_gpiod;
+ struct i2c_client *client;
+ struct input_dev *input_dev;
+struct sistp_driver_data tpinfo;
+};
+
+static int sis_cul_unit(u8 report_id)
+{
+ int ret = NORMAL_LEN_PER_POINT;
+
+ if (report_id != ALL_IN_ONE_PACKAGE) {
+
+ if (IS_AREA(report_id) /*&& IS_TOUCH(report_id)*/)
+ ret += AREA_LEN_PER_POINT;
+
+ if (IS_PRESSURE(report_id))
+ ret += PRESSURE_LEN_PER_POINT;
+ }
+
+ return ret;
+}
+
+static int sis_readpacket(struct i2c_client *client, u8 cmd, u8 *buf)
+{
+ u8 tmpbuf[MAX_BYTE] = {0};
+ int ret = -1;
+ int touchnum = 0;
+ int p_count = 0;
+ int touch_format_id = 0;
+ int location = 0;
+ bool read_first = true;
+
+/*
+ * I2C touch report format
+ *
+ * The controller sends one or two
+ * 64 byte reports (depending on how many
+ * contacts down etc). We read first 64 bytes
+ * and then the second chunk if needed.
+ * The packets are individually CRC
+ * checksummed.
+ *
+ * buf[0] = Low 8 bits of byte count value
+ * buf[1] = High 8 bits of byte counte value
+ * buf[2] = Report ID
+ * buf[touch num * 6 + 2 ] = Touch information
+ * 1 touch point has 6 bytes, it could be none if no touch
+ * buf[touch num * 6 + 3] = Touch numbers
+ *
+ * One touch point information include 6 bytes, the order is
+ *
+ * 1. status = touch down or touch up
+ * 2. id = finger id
+ * 3. x axis low 8 bits
+ * 4. x axis high 8 bits
+ * 5. y axis low 8 bits
+ * 6. y axis high 8 bits
+ */
+ do {
+ if (location >= PACKET_BUFFER_SIZE) {
+ dev_err(&client->dev, "sis_readpacket: buffer overflow\n");
+ return -1;
+ }
+
+ ret = i2c_master_recv(client, tmpbuf, MAX_BYTE);
+
+ if (ret <= 0) {
+ return touchnum;
+ } else if (tmpbuf[P_BYTECOUNT] > MAX_BYTE) {
+ dev_err(&client->dev, "sis_readpacket: invalid bytecout\n");
+ return -1;
+ }
+
+ if (tmpbuf[P_BYTECOUNT] < 10)
+ return touchnum;
+
+ if (read_first)
+ if (tmpbuf[P_BYTECOUNT] == 0)
+ return 0; /* touchnum is 0 */
+
+ touch_format_id = tmpbuf[P_REPORT_ID] & 0xf;
+
+ if ((touch_format_id != TOUCH_FORMAT)
+ && (touch_format_id != HIDI2C_FORMAT)
+ && (tmpbuf[P_REPORT_ID] != ALL_IN_ONE_PACKAGE)) {
+ dev_err(&client->dev, "sis_readpacket: invalid reportid\n");
+ return -1;
+ }
+
+ p_count = (int) tmpbuf[P_BYTECOUNT] - 1; /* start from 0 */
+ if (tmpbuf[P_REPORT_ID] != ALL_IN_ONE_PACKAGE) {
+ if (IS_TOUCH(tmpbuf[P_REPORT_ID])) {
+ p_count -= BYTE_CRC_I2C; /* delete 2 byte crc */
+ } else if (IS_HIDI2C(tmpbuf[P_REPORT_ID])) {
+ p_count -= BYTE_CRC_HIDI2C;
+ } else {
+ dev_err(&client->dev, "sis_readpacket: delete crc error\n");
+ return -1;
+ }
+ if (IS_SCANTIME(tmpbuf[P_REPORT_ID]))
+ p_count -= BYTE_SCANTIME;
+ }
+
+ if (read_first)
+ touchnum = tmpbuf[p_count];
+ else {
+ if (tmpbuf[p_count] != 0) {
+ dev_err(&client->dev, "sis_readpacket: nonzero point count in tail packet\n");
+ return -1;
+ }
+ }
+
+ if ((touch_format_id != HIDI2C_FORMAT) &&
+ (tmpbuf[P_BYTECOUNT] > 3)) {
+ int crc_end = p_count +
+ (IS_SCANTIME(tmpbuf[P_REPORT_ID]) * 2);
+ u16 buf_crc =
+ crc_itu_t(0, tmpbuf + 2, crc_end - 1);
+ int l_package_crc =
+ (IS_SCANTIME(tmpbuf[P_REPORT_ID]) * 2) +
+ p_count + 1;
+ u16 package_crc =
+ get_unaligned_le16(&tmpbuf[l_package_crc]);
+ if (buf_crc != package_crc) {
+ dev_err(&client->dev, "sis_readpacket: CRC Error\n");
+ return -1;
+ }
+ }
+
+ memcpy(&buf[location], &tmpbuf[0], 64);
+ /* Buf_Data [0~63] [64~128] */
+ location += MAX_BYTE;
+ read_first = false;
+ } while (tmpbuf[P_REPORT_ID] != ALL_IN_ONE_PACKAGE &&
+ tmpbuf[p_count] > 5);
+
+ return touchnum;
+}
+
+static irqreturn_t sis_ts_irq_handler(int irq, void *dev_id)
+{
+ struct sis_ts_data *ts = dev_id;
+ struct sistp_driver_data *tpinfo = &ts->tpinfo;
+
+ int ret = -1;
+ int point_unit;
+ u8 buf[PACKET_BUFFER_SIZE] = {0};
+ u8 i = 0, fingers = 0;
+ u8 px = 0, py = 0, pstatus = 0;
+ u8 p_area = 0;
+ u8 p_preasure = 0;
+ int slot;
+
+redo:
+ /* I2C or SMBUS block data read */
+ ret = sis_readpacket(ts->client, SIS_CMD_NORMAL, buf);
+
+ if (ret < 0)
+ goto recheck_irq;
+
+ else if (ret == 0) {
+ fingers = 0;
+ goto label_sync_input;
+ }
+
+ point_unit = sis_cul_unit(buf[P_REPORT_ID]);
+ fingers = ret;
+
+ tpinfo->fingers = fingers = (fingers > MAX_FINGERS ? 0 : fingers);
+
+ for (i = 0; i < fingers; i++) {
+ if ((buf[P_REPORT_ID] != ALL_IN_ONE_PACKAGE) && (i >= 5)) {
+ pstatus = BYTE_BYTECOUNT + BYTE_REPORTID
+ + ((i - 5) * point_unit);
+ pstatus += 64;
+ } else {
+ pstatus = BYTE_BYTECOUNT + BYTE_REPORTID
+ + (i * point_unit);
+ }
+ /* X and Y coordinate locations */
+ px = pstatus + 2;
+ py = px + 2;
+
+ if ((buf[pstatus]) == TOUCHUP) {
+ tpinfo->pt[i].width = 0;
+ tpinfo->pt[i].height = 0;
+ tpinfo->pt[i].pressure = 0;
+ } else if (buf[P_REPORT_ID] == ALL_IN_ONE_PACKAGE
+ && (buf[pstatus]) == TOUCHDOWN) {
+ tpinfo->pt[i].width = 1;
+ tpinfo->pt[i].height = 1;
+ tpinfo->pt[i].pressure = 1;
+ } else if ((buf[pstatus]) == TOUCHDOWN) {
+ p_area = py + 2;
+ p_preasure = py + 2 + (IS_AREA(buf[P_REPORT_ID]) * 2);
+
+ if (IS_AREA(buf[P_REPORT_ID])) {
+ tpinfo->pt[i].width = buf[p_area];
+ tpinfo->pt[i].height = buf[p_area + 1];
+ } else {
+ tpinfo->pt[i].width = 1;
+ tpinfo->pt[i].height = 1;
+ }
+
+ if (IS_PRESSURE(buf[P_REPORT_ID]))
+ tpinfo->pt[i].pressure = (buf[p_preasure]);
+ else
+ tpinfo->pt[i].pressure = 1;
+ } else {
+ dev_err(&ts->client->dev, "Touch status error\n");
+ goto recheck_irq;
+ }
+ tpinfo->pt[i].id = (buf[pstatus + 1]);
+ tpinfo->pt[i].x = le16_to_cpu(get_unaligned_le16(&buf[px]));
+ tpinfo->pt[i].y = le16_to_cpu(get_unaligned_le16(&buf[py]));
+
+ slot = input_mt_get_slot_by_key(
+ ts->input_dev, tpinfo->pt[i].id);
+
+ if (slot < 0)
+ continue;
+
+ input_mt_slot(ts->input_dev, slot);
+ input_mt_report_slot_state(ts->input_dev,
+ MT_TOOL_FINGER, tpinfo->pt[i].pressure);
+
+ if (tpinfo->pt[i].pressure) {
+
+ tpinfo->pt[i].width *= AREA_UNIT;
+ input_report_abs(ts->input_dev, ABS_MT_TOUCH_MAJOR,
+ tpinfo->pt[i].width);
+ tpinfo->pt[i].height *= AREA_UNIT;
+ input_report_abs(ts->input_dev, ABS_MT_TOUCH_MINOR,
+ tpinfo->pt[i].height);
+ input_report_abs(ts->input_dev, ABS_MT_PRESSURE,
+ tpinfo->pt[i].pressure);
+ input_report_abs(ts->input_dev, ABS_MT_POSITION_X,
+ tpinfo->pt[i].x);
+ input_report_abs(ts->input_dev, ABS_MT_POSITION_Y,
+ tpinfo->pt[i].y);
+ }
+ }
+
+label_sync_input:
+ input_mt_sync_frame(ts->input_dev);
+ input_sync(ts->input_dev);
+
+recheck_irq:
+ if (ts->irq_gpiod) {
+ /*
+ * If provided and interrupt gpio and
+ * irq is still asserted,
+ * read data until interrupt is deasserted.
+ */
+ ret = gpiod_get_value_cansleep(ts->irq_gpiod);
+ if (ret == 1)
+ goto redo;
+ }
+
+ return IRQ_HANDLED;
+}
+
+static void sis_ts_reset(struct i2c_client *client, struct sis_ts_data *ts)
+{
+
+ ts->irq_gpiod = devm_gpiod_get_optional(&client->dev,
+ "irq", GPIOD_IN);
+ ts->reset_gpiod = devm_gpiod_get_optional(&client->dev,
+ "reset", GPIOD_OUT_LOW);
+
+ if (ts->reset_gpiod) {
+ /* Get out of reset */
+ msleep(1);
+ gpiod_set_value(ts->reset_gpiod, 1);
+ msleep(1);
+ gpiod_set_value(ts->reset_gpiod, 0);
+ msleep(100);
+ }
+}
+
+static int sis_ts_probe(
+ struct i2c_client *client, const struct i2c_device_id *id)
+{
+ int error = 0;
+ struct sis_ts_data *ts = NULL;
+
+ ts = devm_kzalloc(&client->dev, sizeof(struct sis_ts_data), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ sis_ts_reset(client, ts);
+
+ ts->client = client;
+ i2c_set_clientdata(client, ts);
+
+ ts->input_dev = devm_input_allocate_device(&client->dev);
+ if (!ts->input_dev) {
+ dev_err(&client->dev, "sis_ts_probe: Failed to allocate input device\n");
+ return -ENOMEM;
+ }
+
+ ts->input_dev->name = "sis_touch";
+ ts->input_dev->id.bustype = BUS_I2C;
+
+ input_set_abs_params(ts->input_dev, ABS_MT_PRESSURE,
+ 0, PRESSURE_MAX, 0, 0);
+ input_set_abs_params(ts->input_dev, ABS_MT_TOUCH_MAJOR,
+ 0, AREA_LENGTH_LONGER, 0, 0);
+ input_set_abs_params(ts->input_dev, ABS_MT_TOUCH_MINOR,
+ 0, AREA_LENGTH_SHORT, 0, 0);
+ input_set_abs_params(ts->input_dev, ABS_MT_POSITION_X,
+ 0, SIS_MAX_X, 0, 0);
+ input_set_abs_params(ts->input_dev, ABS_MT_POSITION_Y,
+ 0, SIS_MAX_Y, 0, 0);
+
+ error = input_mt_init_slots(ts->input_dev, MAX_FINGERS,
+ INPUT_MT_DROP_UNUSED | INPUT_MT_DIRECT);
+
+ if (error) {
+ dev_err(&client->dev,
+ "failed to initialize MT slots: %d\n", error);
+ return error;
+ }
+
+ error = input_register_device(ts->input_dev);
+ if (error) {
+ dev_err(&client->dev,
+ "unable to register input device: %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, "request irq failed\n");
+ return error;
+ }
+
+ return 0;
+}
+
+static const struct i2c_device_id sis_ts_id[] = {
+ { SIS_I2C_NAME, 0 },
+ { }
+};
+
+MODULE_DEVICE_TABLE(i2c, sis_ts_id);
+
+#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 struct i2c_driver sis_ts_driver = {
+ .probe = sis_ts_probe,
+ .id_table = sis_ts_id,
+ .driver = {
+ .name = SIS_I2C_NAME,
+ .of_match_table = of_match_ptr(sis_ts_dt_ids),
+ },
+};
+
+module_i2c_driver(sis_ts_driver);
+MODULE_DESCRIPTION("SiS 9200 Family Touchscreen Driver");
+MODULE_LICENSE("GPL v2");
--
1.9.1