[2/2,v1] Input: cy8ctma140 - add driver

Message ID 20200310142818.15415-2-linus.walleij@linaro.org
State New
Headers show
Series
  • Untitled series #36510
Related show

Commit Message

Linus Walleij March 10, 2020, 2:28 p.m.
This adds a new driver for the Cypress CY8CTMA140 touchscreen.

This driver is inspired by out-of-tree code for the Samsung
GT-S7710 mobile phone.

I have tried to compare the structure and behaviour of this
touchscreen to the existing CYTTSP and CYTTSP4 generics and
it seems pretty different. It is also different in character
from the cy8ctmg110_ts.c. It appears to rather be vaguely
related to the Melfas MMS114 driver, yet distinctly
different.

Cc: Ferruh Yigit <fery@cypress.com>
Cc: Henrik Rydberg <rydberg@bitmath.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 MAINTAINERS                            |   6 +
 drivers/input/touchscreen/Kconfig      |  13 +
 drivers/input/touchscreen/Makefile     |   1 +
 drivers/input/touchscreen/cy8ctma140.c | 380 +++++++++++++++++++++++++
 4 files changed, 400 insertions(+)
 create mode 100644 drivers/input/touchscreen/cy8ctma140.c

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 8e7433d74530..39163de1a082 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4628,6 +4628,12 @@  T:	git git://linuxtv.org/anttip/media_tree.git
 S:	Maintained
 F:	drivers/media/common/cypress_firmware*
 
+CYPRESS CY8CTMA140 TOUCHSCREEN DRIVER
+M:	Linus Walleij <linus.walleij@linaro.org>
+L:	linux-input@vger.kernel.org
+S:	Maintained
+F:	drivers/input/touchscreen/cy8ctma140.c
+
 CYTTSP TOUCHSCREEN DRIVER
 M:	Ferruh Yigit <fery@cypress.com>
 L:	linux-input@vger.kernel.org
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index c071f7c407b6..279b96d1761a 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -214,6 +214,19 @@  config TOUCHSCREEN_CY8CTMG110
 	  To compile this driver as a module, choose M here: the
 	  module will be called cy8ctmg110_ts.
 
+config TOUCHSCREEN_CY8CTMA140
+	tristate "cy8ctma140 touchscreen"
+	depends on I2C
+	depends on GPIOLIB || COMPILE_TEST
+	help
+	  Say Y here if you have a Cypress CY8CTMA140 capacitive
+	  touchscreen also just known as "TMA140"
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called cy8ctma140.
+
 config TOUCHSCREEN_CYTTSP_CORE
 	tristate "Cypress TTSP touchscreen"
 	help
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 94c6162409b3..006444c8f87b 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -23,6 +23,7 @@  obj-$(CONFIG_TOUCHSCREEN_BU21029)	+= bu21029_ts.o
 obj-$(CONFIG_TOUCHSCREEN_CHIPONE_ICN8318)	+= chipone_icn8318.o
 obj-$(CONFIG_TOUCHSCREEN_CHIPONE_ICN8505)	+= chipone_icn8505.o
 obj-$(CONFIG_TOUCHSCREEN_CY8CTMG110)	+= cy8ctmg110_ts.o
+obj-$(CONFIG_TOUCHSCREEN_CY8CTMA140)	+= cy8ctma140.o
 obj-$(CONFIG_TOUCHSCREEN_CYTTSP_CORE)	+= cyttsp_core.o
 obj-$(CONFIG_TOUCHSCREEN_CYTTSP_I2C)	+= cyttsp_i2c.o cyttsp_i2c_common.o
 obj-$(CONFIG_TOUCHSCREEN_CYTTSP_SPI)	+= cyttsp_spi.o
diff --git a/drivers/input/touchscreen/cy8ctma140.c b/drivers/input/touchscreen/cy8ctma140.c
new file mode 100644
index 000000000000..fb79f4251122
--- /dev/null
+++ b/drivers/input/touchscreen/cy8ctma140.c
@@ -0,0 +1,380 @@ 
+// 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 <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/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
+#include <linux/delay.h>
+
+/* Used for driver name etc */
+#define CY8CTMA140_NAME "cy8ctma140"
+
+/*
+ * The datasheet claims the device supports 4 fingers but the firmware
+ * I've seen certainly only supports 2 fingers.
+ */
+#define CY8CTMA140_MAX_FINGERS 2
+#define CY8CTMA140_GET_FINGERS 0x00
+#define CY8CTMA140_GET_FW_INFO 0x19
+
+struct cy8ctma140 {
+	struct input_dev *input;
+	struct touchscreen_properties props;
+	struct device *dev;
+	struct i2c_client *client;
+	struct regulator *vcpin;
+	struct regulator *vdd;
+	struct gpio_desc *irq;
+};
+
+static irqreturn_t cy8ctma140_irq_thread(int irq, void *d)
+{
+	struct cy8ctma140 *ts = d;
+	u8 msgbuf0[1];
+	u8 buf[31];
+	struct i2c_msg msg[2] = {
+		{
+			.addr = ts->client->addr,
+			.flags = 0,
+			.len = 1,
+			.buf = msgbuf0,
+		}, {
+			.addr = ts->client->addr,
+			.flags = I2C_M_RD,
+			.len = sizeof(buf),
+			.buf = buf,
+		},
+	};
+	u8 fingers;
+	u16 f1x, f1y, f1z;
+	u16 f2x, f2y, f2z;
+	int ret;
+	int slots[CY8CTMA140_MAX_FINGERS];
+	struct input_mt_pos pos[CY8CTMA140_MAX_FINGERS];
+
+	msgbuf0[0] = CY8CTMA140_GET_FINGERS;
+	ret = __i2c_transfer(ts->client->adapter, msg, 2);
+	if (ret < 0) {
+		dev_err(ts->dev, "error reading message\n");
+		goto evt_out;
+	}
+	if (ret != 2) {
+		dev_err(ts->dev, "wrong number of messages\n");
+		goto evt_out;
+	}
+	if (buf[1] & 0x20) {
+		dev_info(ts->dev, "invalid event\n");
+		goto evt_out;
+	}
+
+	f1x = buf[3] << 8 | buf[4];
+	f1y = buf[5] << 8 | buf[6];
+	f1z = buf[7];
+
+	f2x = buf[9] << 8 | buf[10];
+	f2y = buf[11] << 8 | buf[12];
+	f2z = buf[13];
+
+	fingers = buf[2] & 0x0f;
+	if (fingers == 0) {
+		dev_info(ts->dev, "no fingers\n");
+		goto evt_out;
+	}
+
+	input_mt_assign_slots(ts->input, slots, pos, fingers, 0);
+
+	/*
+	 * When just handling two fingers this code is simple and we do not
+	 * need a loop increasing the complexity. If you need to modify
+	 * this driver for some firmware handling more than 2 fingers,
+	 * this is where you put in an array of coordinated and a loop
+	 * instead.
+	 */
+	if (fingers >= 1) {
+		dev_dbg(ts->dev, "%d fingers: finger 1 ID: %02x (%d, %d, %d)\n",
+			fingers, buf[8] >> 4, f1x, f1y, f1z);
+		input_mt_slot(ts->input, slots[0]);
+		input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
+		input_report_abs(ts->input, ABS_MT_POSITION_X, f1x);
+		input_report_abs(ts->input, ABS_MT_POSITION_Y, f1y);
+		input_report_abs(ts->input, ABS_MT_PRESSURE, f1z);
+	}
+	if (fingers >= 2) {
+		dev_dbg(ts->dev, "%d fingers: finger 2 ID %02x (%d, %d, %d)\n",
+			fingers, buf[8] & 0x0f, f2x, f2y, f2z);
+		input_mt_slot(ts->input, slots[1]);
+		input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
+		input_report_abs(ts->input, ABS_MT_POSITION_X, f2x);
+		input_report_abs(ts->input, ABS_MT_POSITION_Y, f2y);
+		input_report_abs(ts->input, ABS_MT_PRESSURE, f2z);
+	}
+	if (fingers > 2)
+		dev_err(ts->dev, "%d fingers - unsupported!\n", fingers);
+
+	input_mt_sync_frame(ts->input);
+	input_sync(ts->input);
+
+evt_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 recieveing FW info message\n");
+		return ret;
+	}
+	if (ret != 5) {
+		dev_err(ts->dev, "got only %d bytes\n", ret);
+		return -EIO;
+	}
+
+	dev_info(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 ret;
+
+	ret = regulator_enable(ts->vcpin);
+	if (ret) {
+		dev_err(ts->dev, "failed to enable VCPIN voltage\n");
+		return ret;
+	}
+	ret = regulator_enable(ts->vdd);
+	if (ret) {
+		dev_err(ts->dev, "failed to enable VDD voltage\n");
+		regulator_disable(ts->vcpin);
+		return ret;
+	}
+
+	msleep(250);
+
+	return 0;
+}
+
+static void cy8ctma140_power_down(struct cy8ctma140 *ts)
+{
+	regulator_disable(ts->vdd);
+	regulator_disable(ts->vcpin);
+}
+
+/* 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 ret;
+
+	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;
+
+	/*
+	 * 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);
+
+	ret = input_mt_init_slots(input, CY8CTMA140_MAX_FINGERS,
+				  INPUT_MT_DIRECT);
+	if (ret)
+		return ret;
+
+	input->name = CY8CTMA140_NAME;
+	input->phys = "inpus/ts";
+	input->id.bustype = BUS_I2C;
+	input_set_drvdata(input, ts);
+
+	/* VCPIN is the analog voltage supply */
+	ts->vcpin = devm_regulator_get(dev, "vcpin");
+	if (IS_ERR(ts->vcpin)) {
+		if (PTR_ERR(ts->vcpin) != -EPROBE_DEFER)
+			dev_err(dev, "Failed to get VCPIN regulator %d\n",
+				(int)PTR_ERR(ts->vcpin));
+		return PTR_ERR(ts->vcpin);
+	}
+	/* According to datasheet this should be in the 2.7-3.6 V range */
+	ret = regulator_set_voltage(ts->vcpin, 2700000, 3600000);
+	if (ret) {
+		dev_err(dev, "failed to set VCPIN voltage\n");
+		return ret;
+	}
+
+	/*
+	 * 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->vdd = devm_regulator_get(dev, "vdd");
+	if (IS_ERR(ts->vdd)) {
+		if (PTR_ERR(ts->vdd) != -EPROBE_DEFER)
+			dev_err(dev, "Failed to get VDD regulator %d\n",
+				(int)PTR_ERR(ts->vdd));
+		return PTR_ERR(ts->vdd);
+	}
+	/* According to datasheet this should be in the 1.71-3.6 V range */
+	ret = regulator_set_voltage(ts->vdd, 2700000, 3600000);
+	if (ret) {
+		dev_err(dev, "failed to set VDD voltage\n");
+		return ret;
+	}
+
+	ret = cy8ctma140_power_up(ts);
+	if (ret)
+		return ret;
+	ret = devm_add_action_or_reset(dev, cy8ctma140_power_off_action, ts);
+	if (ret) {
+		dev_err(dev, "failed to install power off handler\n");
+		return ret;
+	}
+
+	ret = devm_request_threaded_irq(dev, client->irq, NULL,
+					cy8ctma140_irq_thread,
+					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+					CY8CTMA140_NAME, ts);
+	if (ret) {
+		dev_err(dev, "irq %d busy? error %d\n", client->irq, ret);
+		goto err_reg_dis;
+	}
+
+	ret = cy8ctma140_init(ts);
+	if (ret)
+		return ret;
+
+	ret = input_register_device(input);
+	if (ret)
+		goto err_reg_dis;
+
+	i2c_set_clientdata(client, ts);
+
+	device_init_wakeup(dev, 1);
+	return 0;
+
+err_reg_dis:
+	cy8ctma140_power_down(ts);
+	return ret;
+}
+
+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))
+		enable_irq_wake(client->irq);
+	else
+		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 ret;
+
+	if (device_may_wakeup(&client->dev)) {
+		disable_irq_wake(client->irq);
+	} else {
+		ret = cy8ctma140_power_up(ts);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(cy8ctma140_pm, cy8ctma140_suspend, cy8ctma140_resume);
+
+static const struct i2c_device_id cy8ctma140_idtable[] = {
+	{ CY8CTMA140_NAME, 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, cy8ctma140_idtable);
+
+static const struct of_device_id cy8ctma140_of_match[] = {
+	{
+		.compatible = "cypress,cy8ctma140",
+	},
+};
+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");