diff options
Diffstat (limited to 'drivers/input/touchscreen/sis_i2c.c')
| -rw-r--r-- | drivers/input/touchscreen/sis_i2c.c | 404 |
1 files changed, 404 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/sis_i2c.c b/drivers/input/touchscreen/sis_i2c.c new file mode 100644 index 000000000..6274555f1 --- /dev/null +++ b/drivers/input/touchscreen/sis_i2c.c @@ -0,0 +1,404 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Touch Screen driver for SiS 9200 family I2C Touch panels + * + * Copyright (C) 2015 SiS, Inc. + * Copyright (C) 2016 Nextfour Group + */ + +#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; + + 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>"); |