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Message-ID: <20160702001719.GA36469@dtor-ws>
Date: Fri, 1 Jul 2016 17:17:19 -0700
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: mika.penttila@...tfour.com
Cc: linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
tammy_tseng@....com, yuger_yu@....com
Subject: Re: [PATCH v5 1/2] Input: Driver for SiS 9200 family I2C touchscreen
controller.
Hi Mika,
On Fri, May 06, 2016 at 08:22:16AM +0300, mika.penttila@...tfour.com wrote:
> From: Mika Penttilä <mika.penttila@...tfour.com>
>
> 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 Penttilä <mika.penttila@...tfour.com>
> Acked-by: Tammy Tseng <tammy_tseng@....com>
> Acked-by: Yuger Yu <yuger_yu@....com>
> ---
> 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>
Not needed I think.
> +#include <linux/platform_device.h>
Not needed.
> +#include <linux/linkage.h>
Not needed.
> +#include <linux/slab.h>
> +#include <linux/of_gpio.h>
Not needed (but gpio/consumer.h is)
> +#include <linux/uaccess.h>
> +#include <linux/irq.h>
Not needed I think.
> +#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;
There is actually no need to have storage for contact info in the driver
object, you can report them as you parse them.
> +};
> +
> +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;
I must say that I find this logic of combining 2 packets into one larger
confusing. I tried to rework it so that we fetch, parse and report
contacts as we go. Please see below.
> +}
> +
> +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]));
get_unaligned_le16() already converts to native CPU endianness, calling
le16_to_cpu on it is a mistake.
> +
> + 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);
msleep(1) will not work well with low HZ values, you want to use
usleep_range().
> + 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;
No need to initialize to 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);
It seems that the hardware keeps track of the contact identity and
reports the release events, so I do not think we need
INPUT_MT_DROP_UNUSED.
> +
> + 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" },
DT folks object to using underscores in properties, this should be
"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
>
Below is the version of the patch with reworked parsing and reporting
code. Please let me know if it is messed up or if it works for you.
Thanks.
--
Dmitry
Input: add driver for SiS 9200 family I2C touchscreen controllers
From: Mika Penttilä <mika.penttila@...tfour.com>
This is a driver for SiS 9200 family touchscreen controllers using I2C bus.
Signed-off-by: Mika Penttilä <mika.penttila@...tfour.com>
Acked-by: Tammy Tseng <tammy_tseng@....com>
Acked-by: Yuger Yu <yuger_yu@....com>
Patchwork-Id: 9029121
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
---
.../bindings/input/touchscreen/sis_i2c.txt | 33 ++
.../devicetree/bindings/vendor-prefixes.txt | 1
drivers/input/touchscreen/Kconfig | 12 +
drivers/input/touchscreen/Makefile | 1
drivers/input/touchscreen/sis_i2c.c | 409 ++++++++++++++++++++
5 files changed, 456 insertions(+)
create mode 100644 Documentation/devicetree/bindings/input/touchscreen/sis_i2c.txt
create mode 100644 drivers/input/touchscreen/sis_i2c.c
diff --git a/Documentation/devicetree/bindings/input/touchscreen/sis_i2c.txt b/Documentation/devicetree/bindings/input/touchscreen/sis_i2c.txt
new file mode 100644
index 0000000..6b06b20
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/sis_i2c.txt
@@ -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-gpio: the gpio pin used as attention line
+- reset-gpio: 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>;
+ attn-gpio = <&gpio3 19 GPIO_ACTIVE_LOW>;
+ reset-gpio = <&gpio2 30 GPIO_ACTIVE_LOW>;
+ };
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 80fdbe2..99029cf 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -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
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index ee02dc7..9a29ad1 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -1181,4 +1181,16 @@ 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 || 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.
+
endif
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 3315882..e547399 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -64,6 +64,7 @@ obj-$(CONFIG_TOUCHSCREEN_PENMOUNT) += penmount.o
obj-$(CONFIG_TOUCHSCREEN_PIXCIR) += pixcir_i2c_ts.o
obj-$(CONFIG_TOUCHSCREEN_RM_TS) += raydium_i2c_ts.o
obj-$(CONFIG_TOUCHSCREEN_S3C2410) += s3c2410_ts.o
+obj-$(CONFIG_TOUCHSCREEN_SIS_I2C) += sis_i2c.o
obj-$(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..bc96c9d
--- /dev/null
+++ b/drivers/input/touchscreen/sis_i2c.c
@@ -0,0 +1,409 @@
+/*
+ * Touch Screen driver for SiS 9200 family I2C Touch panels
+ *
+ * Copyright (C) 2015 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/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_PKT_STATUS_OFFSET 0
+#define SIS_PKT_ID_OFFSET 1 /* Contact ID */
+#define SIS_PKT_X_OFFSET 2
+#define SIS_PKT_Y_OFFSET 4
+#define SIS_PKT_WIDTH_OFFSET 6
+#define SIS_PKT_HEIGHT_OFFSET 7
+#define SIS_PKT_PRESSURE_OFFSET(id) (SIS_PKT_HAS_AREA(id) ? 8 : 6)
+
+/* Individual contact state */
+#define SIS_STATUS_UP 0x3
+#define SIS_STATUS_DOWN 0x0
+
+/* 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_ID_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 + SIS_PKT_LEN_OFFSET,
+ len - SIS_PKT_LEN_OFFSET - 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_PKT_STATUS_OFFSET];
+ u8 pressure;
+ u8 height, width;
+
+ if (status != SIS_STATUS_DOWN && status != SIS_STATUS_UP) {
+ dev_err(&ts->client->dev, "Unexpected touch status: %#02x\n",
+ data[SIS_PKT_STATUS_OFFSET]);
+ return -EINVAL;
+ }
+
+ slot = input_mt_get_slot_by_key(input, data[SIS_PKT_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_PKT_WIDTH_OFFSET];
+ height = data[SIS_PKT_HEIGHT_OFFSET];
+ }
+
+ if (SIS_PKT_HAS_PRESSURE(id))
+ pressure = data[SIS_PKT_PRESSURE_OFFSET(id)];
+ }
+
+ 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,
+ get_unaligned_le16(&data[SIS_PKT_X_OFFSET]));
+ input_report_abs(input, ABS_MT_POSITION_Y,
+ get_unaligned_le16(&data[SIS_PKT_Y_OFFSET]));
+ }
+
+ 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");
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