| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Driver for Cypress CY8CTMA140 (TMA140) touchscreen |
| * (C) 2020 Linus Walleij <linus.walleij@linaro.org> |
| * (C) 2007 Cypress |
| * (C) 2007 Google, Inc. |
| * |
| * Inspired by the tma140_skomer.c driver in the Samsung GT-S7710 code |
| * drop. The GT-S7710 is codenamed "Skomer", the code also indicates |
| * that the same touchscreen was used in a product called "Lucas". |
| * |
| * The code drop for GT-S7710 also contains a firmware downloader and |
| * 15 (!) versions of the firmware drop from Cypress. But here we assume |
| * the firmware got downloaded to the touchscreen flash successfully and |
| * just use it to read the fingers. The shipped vendor driver does the |
| * same. |
| */ |
| |
| #include <asm/unaligned.h> |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/input.h> |
| #include <linux/input/touchscreen.h> |
| #include <linux/input/mt.h> |
| #include <linux/slab.h> |
| #include <linux/interrupt.h> |
| #include <linux/io.h> |
| #include <linux/i2c.h> |
| #include <linux/regulator/consumer.h> |
| #include <linux/delay.h> |
| |
| #define CY8CTMA140_NAME "cy8ctma140" |
| |
| #define CY8CTMA140_MAX_FINGERS 4 |
| |
| #define CY8CTMA140_GET_FINGERS 0x00 |
| #define CY8CTMA140_GET_FW_INFO 0x19 |
| |
| /* This message also fits some bytes for touchkeys, if used */ |
| #define CY8CTMA140_PACKET_SIZE 31 |
| |
| #define CY8CTMA140_INVALID_BUFFER_BIT 5 |
| |
| struct cy8ctma140 { |
| struct input_dev *input; |
| struct touchscreen_properties props; |
| struct device *dev; |
| struct i2c_client *client; |
| struct regulator_bulk_data regulators[2]; |
| u8 prev_fingers; |
| u8 prev_f1id; |
| u8 prev_f2id; |
| }; |
| |
| static void cy8ctma140_report(struct cy8ctma140 *ts, u8 *data, int n_fingers) |
| { |
| static const u8 contact_offsets[] = { 0x03, 0x09, 0x10, 0x16 }; |
| u8 *buf; |
| u16 x, y; |
| u8 w; |
| u8 id; |
| int slot; |
| int i; |
| |
| for (i = 0; i < n_fingers; i++) { |
| buf = &data[contact_offsets[i]]; |
| |
| /* |
| * Odd contacts have contact ID in the lower nibble of |
| * the preceding byte, whereas even contacts have it in |
| * the upper nibble of the following byte. |
| */ |
| id = i % 2 ? buf[-1] & 0x0f : buf[5] >> 4; |
| slot = input_mt_get_slot_by_key(ts->input, id); |
| if (slot < 0) |
| continue; |
| |
| x = get_unaligned_be16(buf); |
| y = get_unaligned_be16(buf + 2); |
| w = buf[4]; |
| |
| dev_dbg(ts->dev, "finger %d: ID %02x (%d, %d) w: %d\n", |
| slot, id, x, y, w); |
| |
| input_mt_slot(ts->input, slot); |
| input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true); |
| touchscreen_report_pos(ts->input, &ts->props, x, y, true); |
| input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR, w); |
| } |
| |
| input_mt_sync_frame(ts->input); |
| input_sync(ts->input); |
| } |
| |
| static irqreturn_t cy8ctma140_irq_thread(int irq, void *d) |
| { |
| struct cy8ctma140 *ts = d; |
| u8 cmdbuf[] = { CY8CTMA140_GET_FINGERS }; |
| u8 buf[CY8CTMA140_PACKET_SIZE]; |
| struct i2c_msg msg[] = { |
| { |
| .addr = ts->client->addr, |
| .flags = 0, |
| .len = sizeof(cmdbuf), |
| .buf = cmdbuf, |
| }, { |
| .addr = ts->client->addr, |
| .flags = I2C_M_RD, |
| .len = sizeof(buf), |
| .buf = buf, |
| }, |
| }; |
| u8 n_fingers; |
| int ret; |
| |
| ret = i2c_transfer(ts->client->adapter, msg, ARRAY_SIZE(msg)); |
| if (ret != ARRAY_SIZE(msg)) { |
| if (ret < 0) |
| dev_err(ts->dev, "error reading message: %d\n", ret); |
| else |
| dev_err(ts->dev, "wrong number of messages\n"); |
| goto out; |
| } |
| |
| if (buf[1] & BIT(CY8CTMA140_INVALID_BUFFER_BIT)) { |
| dev_dbg(ts->dev, "invalid event\n"); |
| goto out; |
| } |
| |
| n_fingers = buf[2] & 0x0f; |
| if (n_fingers > CY8CTMA140_MAX_FINGERS) { |
| dev_err(ts->dev, "unexpected number of fingers: %d\n", |
| n_fingers); |
| goto out; |
| } |
| |
| cy8ctma140_report(ts, buf, n_fingers); |
| |
| out: |
| return IRQ_HANDLED; |
| } |
| |
| static int cy8ctma140_init(struct cy8ctma140 *ts) |
| { |
| u8 addr[1]; |
| u8 buf[5]; |
| int ret; |
| |
| addr[0] = CY8CTMA140_GET_FW_INFO; |
| ret = i2c_master_send(ts->client, addr, 1); |
| if (ret < 0) { |
| dev_err(ts->dev, "error sending FW info message\n"); |
| return ret; |
| } |
| ret = i2c_master_recv(ts->client, buf, 5); |
| if (ret < 0) { |
| dev_err(ts->dev, "error receiving FW info message\n"); |
| return ret; |
| } |
| if (ret != 5) { |
| dev_err(ts->dev, "got only %d bytes\n", ret); |
| return -EIO; |
| } |
| |
| dev_dbg(ts->dev, "vendor %c%c, HW ID %.2d, FW ver %.4d\n", |
| buf[0], buf[1], buf[3], buf[4]); |
| |
| return 0; |
| } |
| |
| static int cy8ctma140_power_up(struct cy8ctma140 *ts) |
| { |
| int error; |
| |
| error = regulator_bulk_enable(ARRAY_SIZE(ts->regulators), |
| ts->regulators); |
| if (error) { |
| dev_err(ts->dev, "failed to enable regulators\n"); |
| return error; |
| } |
| |
| msleep(250); |
| |
| return 0; |
| } |
| |
| static void cy8ctma140_power_down(struct cy8ctma140 *ts) |
| { |
| regulator_bulk_disable(ARRAY_SIZE(ts->regulators), |
| ts->regulators); |
| } |
| |
| /* Called from the registered devm action */ |
| static void cy8ctma140_power_off_action(void *d) |
| { |
| struct cy8ctma140 *ts = d; |
| |
| cy8ctma140_power_down(ts); |
| } |
| |
| static int cy8ctma140_probe(struct i2c_client *client) |
| { |
| struct cy8ctma140 *ts; |
| struct input_dev *input; |
| struct device *dev = &client->dev; |
| int error; |
| |
| ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL); |
| if (!ts) |
| return -ENOMEM; |
| |
| input = devm_input_allocate_device(dev); |
| if (!input) |
| return -ENOMEM; |
| |
| ts->dev = dev; |
| ts->client = client; |
| ts->input = input; |
| |
| input_set_capability(input, EV_ABS, ABS_MT_POSITION_X); |
| input_set_capability(input, EV_ABS, ABS_MT_POSITION_Y); |
| /* One byte for width 0..255 so this is the limit */ |
| input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0); |
| /* |
| * This sets up event max/min capabilities and fuzz. |
| * Some DT properties are compulsory so we do not need |
| * to provide defaults for X/Y max or pressure max. |
| * |
| * We just initialize a very simple MT touchscreen here, |
| * some devices use the capability of this touchscreen to |
| * provide touchkeys, and in that case this needs to be |
| * extended to handle touchkey input. |
| * |
| * The firmware takes care of finger tracking and dropping |
| * invalid ranges. |
| */ |
| touchscreen_parse_properties(input, true, &ts->props); |
| input_abs_set_fuzz(input, ABS_MT_POSITION_X, 0); |
| input_abs_set_fuzz(input, ABS_MT_POSITION_Y, 0); |
| |
| error = input_mt_init_slots(input, CY8CTMA140_MAX_FINGERS, |
| INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED); |
| if (error) |
| return error; |
| |
| input->name = CY8CTMA140_NAME; |
| input->id.bustype = BUS_I2C; |
| input_set_drvdata(input, ts); |
| |
| /* |
| * VCPIN is the analog voltage supply |
| * VDD is the digital voltage supply |
| * since the voltage range of VDD overlaps that of VCPIN, |
| * many designs to just supply both with a single voltage |
| * source of ~3.3 V. |
| */ |
| ts->regulators[0].supply = "vcpin"; |
| ts->regulators[1].supply = "vdd"; |
| error = devm_regulator_bulk_get(dev, ARRAY_SIZE(ts->regulators), |
| ts->regulators); |
| if (error) |
| return dev_err_probe(dev, error, "Failed to get regulators\n"); |
| |
| error = cy8ctma140_power_up(ts); |
| if (error) |
| return error; |
| |
| error = devm_add_action_or_reset(dev, cy8ctma140_power_off_action, ts); |
| if (error) { |
| dev_err(dev, "failed to install power off handler\n"); |
| return error; |
| } |
| |
| error = devm_request_threaded_irq(dev, client->irq, |
| NULL, cy8ctma140_irq_thread, |
| IRQF_ONESHOT, CY8CTMA140_NAME, ts); |
| if (error) { |
| dev_err(dev, "irq %d busy? error %d\n", client->irq, error); |
| return error; |
| } |
| |
| error = cy8ctma140_init(ts); |
| if (error) |
| return error; |
| |
| error = input_register_device(input); |
| if (error) |
| return error; |
| |
| i2c_set_clientdata(client, ts); |
| |
| return 0; |
| } |
| |
| static int cy8ctma140_suspend(struct device *dev) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| struct cy8ctma140 *ts = i2c_get_clientdata(client); |
| |
| if (!device_may_wakeup(&client->dev)) |
| cy8ctma140_power_down(ts); |
| |
| return 0; |
| } |
| |
| static int cy8ctma140_resume(struct device *dev) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| struct cy8ctma140 *ts = i2c_get_clientdata(client); |
| int error; |
| |
| if (!device_may_wakeup(&client->dev)) { |
| error = cy8ctma140_power_up(ts); |
| if (error) |
| return error; |
| } |
| |
| return 0; |
| } |
| |
| static DEFINE_SIMPLE_DEV_PM_OPS(cy8ctma140_pm, |
| cy8ctma140_suspend, cy8ctma140_resume); |
| |
| static const struct i2c_device_id cy8ctma140_idtable[] = { |
| { CY8CTMA140_NAME, 0 }, |
| { /* sentinel */ } |
| }; |
| MODULE_DEVICE_TABLE(i2c, cy8ctma140_idtable); |
| |
| static const struct of_device_id cy8ctma140_of_match[] = { |
| { .compatible = "cypress,cy8ctma140", }, |
| { /* sentinel */ } |
| }; |
| MODULE_DEVICE_TABLE(of, cy8ctma140_of_match); |
| |
| static struct i2c_driver cy8ctma140_driver = { |
| .driver = { |
| .name = CY8CTMA140_NAME, |
| .pm = pm_sleep_ptr(&cy8ctma140_pm), |
| .of_match_table = cy8ctma140_of_match, |
| }, |
| .id_table = cy8ctma140_idtable, |
| .probe = cy8ctma140_probe, |
| }; |
| module_i2c_driver(cy8ctma140_driver); |
| |
| MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>"); |
| MODULE_DESCRIPTION("CY8CTMA140 TouchScreen Driver"); |
| MODULE_LICENSE("GPL v2"); |