--- /dev/null
+// 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,
+ const struct i2c_device_id *id)
+{
+ 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 __maybe_unused 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 __maybe_unused 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 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 = &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");
projects / users / dwmw2 / linux.git / commitdiff