1 files changed, 353 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/cy8ctma140.c b/drivers/input/touchscreen/cy8ctma140.c
new file mode 100644
index 000000000000..a9be29139cbf
--- /dev/null
+++ b/drivers/input/touchscreen/cy8ctma140.c
@@ -0,0 +1,353 @@
+// 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");