// 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) { if (error != -EPROBE_DEFER) dev_err(dev, "Failed to get regulators %d\n", error); return error; } 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_new = cy8ctma140_probe, }; module_i2c_driver(cy8ctma140_driver); MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>"); MODULE_DESCRIPTION("CY8CTMA140 TouchScreen Driver"); MODULE_LICENSE("GPL v2");