diff options
Diffstat (limited to 'drivers/input/touchscreen/cy8ctma140.c')
| -rw-r--r-- | drivers/input/touchscreen/cy8ctma140.c | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/cy8ctma140.c b/drivers/input/touchscreen/cy8ctma140.c new file mode 100644 index 0000000000..ea3895167b --- /dev/null +++ b/drivers/input/touchscreen/cy8ctma140.c @@ -0,0 +1,349 @@ +// 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"); |