fingerprint: fpc: Add fpc driver

Bug: 173354002
Test: Build Pass and check driver node
Signed-off-by: eddielan <eddielan@google.com>
Change-Id: I68a02ed6a83eb4e7b68aea8ff21a2f173e5b3f52

3 files changed, 603 insertions, 0 deletions

diff --git a/Kconfig b/Kconfig
new file mode 100644
index 0000000..6064dbc
--- /dev/null
+++ b/Kconfig
@@ -0,0 +1,7 @@
+#-----------------------------------#
+#    Kconfig for FingerprintCard    #
+#-----------------------------------#
+
+config FPC_FINGERPRINT
+	default n
+	tristate "fpc1020 fingerprint driver"
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..f563b5d
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,12 @@
+#---------------------------------#
+#  Makefile for FignerprintCard   #
+#---------------------------------#
+
+obj-$(CONFIG_FPC_FINGERPRINT) += fpc1020_platform_tee.o
+
+KERNEL_SRC ?= /lib/modules/$(shell uname -r)/build
+M ?= $(shell pwd)
+KBUILD_OPTIONS += CONFIG_FPC_FINGERPRINT=m
+
+modules modules_install clean:
+	$(MAKE) -C $(KERNEL_SRC) M=$(M) $(KBUILD_OPTIONS) W=1 $(@)
diff --git a/fpc1020_platform_tee.c b/fpc1020_platform_tee.c
new file mode 100644
index 0000000..ba64cfd
--- /dev/null
+++ b/fpc1020_platform_tee.c
@@ -0,0 +1,584 @@
+/*
+ * FPC1020 Fingerprint sensor device driver
+ *
+ * This driver will control the platform resources that the FPC fingerprint
+ * sensor needs to operate. The major things are probing the sensor to check
+ * that it is actually connected and let the Kernel know this and with that also
+ * enabling and disabling of regulators, controlling GPIOs such as sensor reset
+ * line, sensor IRQ line.
+ *
+ * The driver will expose most of its available functionality in sysfs which
+ * enables dynamic control of these features from eg. a user space process.
+ *
+ * The sensor's IRQ events will be pushed to Kernel's event handling system and
+ * are exposed in the drivers event node.
+ *
+ * This driver will NOT send any commands to the sensor it only controls the
+ * electrical parts.
+ *
+ *
+ * Copyright (c) 2015 Fingerprint Cards AB <tech@fingerprints.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License Version 2
+ * as published by the Free Software Foundation.
+ */
+#include <linux/atomic.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+
+#define FPC_TTW_HOLD_TIME 1000
+
+#define RESET_LOW_SLEEP_MIN_US 5000
+#define RESET_LOW_SLEEP_MAX_US (RESET_LOW_SLEEP_MIN_US + 100)
+#define RESET_HIGH_SLEEP1_MIN_US 100
+#define RESET_HIGH_SLEEP1_MAX_US (RESET_HIGH_SLEEP1_MIN_US + 100)
+#define RESET_HIGH_SLEEP2_MIN_US 5000
+#define RESET_HIGH_SLEEP2_MAX_US (RESET_HIGH_SLEEP2_MIN_US + 100)
+#define PWR_ON_SLEEP_MIN_US 100
+#define PWR_ON_SLEEP_MAX_US (PWR_ON_SLEEP_MIN_US + 900)
+
+#define NUM_PARAMS_REG_ENABLE_SET 2
+
+struct vreg_config {
+	char *name;
+	unsigned long vmin;
+	unsigned long vmax;
+	int ua_load;
+};
+
+static const struct vreg_config vreg_conf[] = {
+	{ "vdd_ana", 1800000UL, 1800000UL, 6000, },
+	{ "vcc_spi", 1800000UL, 1800000UL, 10, },
+	{ "vdd_io", 1800000UL, 1800000UL, 6000, },
+};
+
+struct fpc1020_data {
+	struct device *dev;
+
+	struct regulator *vreg[ARRAY_SIZE(vreg_conf)];
+
+	struct wakeup_source *ttw_ws;
+	int irq_gpio;
+	int rst_gpio;
+	struct mutex lock; /* To set/get exported values in sysfs */
+	bool prepared;
+	atomic_t wakeup_enabled; /* Used both in ISR and non-ISR */
+};
+
+static int vreg_setup(struct fpc1020_data *fpc1020, const char *name,
+	bool enable)
+{
+	size_t i;
+	int rc;
+	struct regulator *vreg;
+	struct device *dev = fpc1020->dev;
+
+	for (i = 0; i < ARRAY_SIZE(fpc1020->vreg); i++) {
+		const char *n = vreg_conf[i].name;
+
+		if (!strncmp(n, name, strlen(n)))
+			goto found;
+	}
+
+	dev_err(dev, "Regulator %s not found\n", name);
+
+	return -EINVAL;
+
+found:
+	vreg = fpc1020->vreg[i];
+	if (enable) {
+		if (!vreg) {
+			vreg = regulator_get(dev, name);
+			if (IS_ERR(vreg)) {
+				dev_err(dev, "Unable to get %s\n", name);
+				return PTR_ERR(vreg);
+			}
+		}
+
+		if (regulator_count_voltages(vreg) > 0) {
+			rc = regulator_set_voltage(vreg, vreg_conf[i].vmin,
+					vreg_conf[i].vmax);
+			if (rc)
+				dev_err(dev,
+					"Unable to set voltage on %s, %d\n",
+					name, rc);
+		}
+
+		rc = regulator_enable(vreg);
+		if (rc) {
+			dev_err(dev, "error enabling %s: %d\n", name, rc);
+			regulator_put(vreg);
+			vreg = NULL;
+		}
+		fpc1020->vreg[i] = vreg;
+	} else {
+		if (vreg) {
+			if (regulator_is_enabled(vreg)) {
+				regulator_disable(vreg);
+				dev_dbg(dev, "disabled %s\n", name);
+			}
+			regulator_put(vreg);
+			fpc1020->vreg[i] = NULL;
+		}
+		rc = 0;
+	}
+
+	return rc;
+}
+
+/**
+ * sysfs node for controlling clocks.
+ *
+ * This is disabled in platform variant of this driver but kept for
+ * backwards compatibility. Only prints a debug print that it is
+ * disabled.
+ */
+static ssize_t clk_enable_set(struct device *dev,
+	struct device_attribute *attr,
+	const char *buf, size_t count)
+{
+	dev_dbg(dev,
+		"clk_enable sysfs node not enabled in platform driver\n");
+
+	return count;
+}
+static DEVICE_ATTR(clk_enable, 0200, NULL, clk_enable_set);
+
+static ssize_t regulator_enable_set(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct fpc1020_data *fpc1020 = dev_get_drvdata(dev);
+	char op;
+	char name[16];
+	int rc;
+	bool enable;
+
+	if (NUM_PARAMS_REG_ENABLE_SET != sscanf(buf, "%15[^,],%c", name, &op))
+		return -EINVAL;
+	if (op == 'e')
+		enable = true;
+	else if (op == 'd')
+		enable = false;
+	else
+		return -EINVAL;
+
+	mutex_lock(&fpc1020->lock);
+	rc = vreg_setup(fpc1020, name, enable);
+	mutex_unlock(&fpc1020->lock);
+
+	return rc ? rc : count;
+}
+static DEVICE_ATTR(regulator_enable, 0200, NULL, regulator_enable_set);
+
+static int hw_reset(struct fpc1020_data *fpc1020)
+{
+	int irq_gpio;
+    int rst_gpio;
+	struct device *dev = fpc1020->dev;
+
+	// Configure reset pin as High
+	gpio_set_value(fpc1020->rst_gpio, 1);
+	usleep_range(RESET_HIGH_SLEEP1_MIN_US, RESET_HIGH_SLEEP1_MAX_US);
+	rst_gpio = gpio_get_value(fpc1020->rst_gpio);
+	dev_info(dev, "RST after reset_active %d\n",rst_gpio);
+
+	// Configure reset pin as low
+	gpio_set_value(fpc1020->rst_gpio, 0);
+	usleep_range(RESET_LOW_SLEEP_MIN_US, RESET_LOW_SLEEP_MAX_US);
+	rst_gpio = gpio_get_value(fpc1020->rst_gpio);
+	dev_info(dev, "RST after reset_reset %d\n",rst_gpio);
+
+	// Configure reset pin as High
+	gpio_set_value(fpc1020->rst_gpio, 1);
+	usleep_range(RESET_HIGH_SLEEP2_MIN_US, RESET_HIGH_SLEEP2_MAX_US);
+	rst_gpio = gpio_get_value(fpc1020->rst_gpio);
+	dev_info(dev, "RST after reset_active %d\n",rst_gpio);
+
+	// Check interrupt pin after HW reset
+	irq_gpio = gpio_get_value(fpc1020->irq_gpio);
+	dev_info(dev, "IRQ after reset %d\n", irq_gpio);
+
+	return 0;
+}
+
+static ssize_t hw_reset_set(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	int rc;
+	struct fpc1020_data *fpc1020 = dev_get_drvdata(dev);
+
+	if (!strncmp(buf, "reset", strlen("reset"))) {
+		mutex_lock(&fpc1020->lock);
+		rc = hw_reset(fpc1020);
+		mutex_unlock(&fpc1020->lock);
+	} else {
+		return -EINVAL;
+	}
+
+	return rc ? rc : count;
+}
+static DEVICE_ATTR(hw_reset, 0200, NULL, hw_reset_set);
+
+/**
+ * Will setup GPIOs, and regulators to correctly initialize the touch sensor to
+ * be ready for work.
+ *
+ * In the correct order according to the sensor spec this function will
+ * enable/disable regulators, and reset line, all to set the sensor in a
+ * correct power on or off state "electrical" wise.
+ *
+ * @see  device_prepare_set
+ * @note This function will not send any commands to the sensor it will only
+ *       control it "electrically".
+ */
+static int device_prepare(struct fpc1020_data *fpc1020, bool enable)
+{
+	int rc;
+
+	mutex_lock(&fpc1020->lock);
+	if (enable && !fpc1020->prepared) {
+		fpc1020->prepared = true;
+		gpio_direction_output(fpc1020->rst_gpio, 0);
+
+		rc = vreg_setup(fpc1020, "vcc_spi", true);
+		if (rc)
+			goto exit;
+
+		rc = vreg_setup(fpc1020, "vdd_io", true);
+		if (rc)
+			goto exit_1;
+
+		rc = vreg_setup(fpc1020, "vdd_ana", true);
+		if (rc)
+			goto exit_2;
+
+		usleep_range(PWR_ON_SLEEP_MIN_US, PWR_ON_SLEEP_MAX_US);
+
+		/* As we can't control chip select here the other part of the
+		 * sensor driver eg. the TEE driver needs to do a _SOFT_ reset
+		 * on the sensor after power up to be sure that the sensor is
+		 * in a good state after power up. Okeyed by ASIC. */
+
+		gpio_direction_output(fpc1020->rst_gpio, 1);
+	} else if (!enable && fpc1020->prepared) {
+		rc = 0;
+		gpio_direction_output(fpc1020->rst_gpio, 0);
+
+		usleep_range(PWR_ON_SLEEP_MIN_US, PWR_ON_SLEEP_MAX_US);
+
+		(void)vreg_setup(fpc1020, "vdd_ana", false);
+exit_2:
+		(void)vreg_setup(fpc1020, "vdd_io", false);
+exit_1:
+		(void)vreg_setup(fpc1020, "vcc_spi", false);
+exit:
+		fpc1020->prepared = false;
+	} else {
+		rc = 0;
+	}
+	mutex_unlock(&fpc1020->lock);
+
+	return rc;
+}
+
+/**
+ * sysfs node to enable/disable (power up/power down) the touch sensor
+ *
+ * @see device_prepare
+ */
+static ssize_t device_prepare_set(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	int rc;
+	struct fpc1020_data *fpc1020 = dev_get_drvdata(dev);
+
+	if (!strncmp(buf, "enable", strlen("enable")))
+		rc = device_prepare(fpc1020, true);
+	else if (!strncmp(buf, "disable", strlen("disable")))
+		rc = device_prepare(fpc1020, false);
+	else
+		return -EINVAL;
+
+	return rc ? rc : count;
+}
+static DEVICE_ATTR(device_prepare, 0200, NULL, device_prepare_set);
+
+/**
+ * sysfs node for controlling whether the driver is allowed
+ * to wake up the platform on interrupt.
+ */
+static ssize_t wakeup_enable_set(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct fpc1020_data *fpc1020 = dev_get_drvdata(dev);
+	ssize_t ret = count;
+
+	mutex_lock(&fpc1020->lock);
+	if (!strncmp(buf, "enable", strlen("enable")))
+		atomic_set(&fpc1020->wakeup_enabled, 1);
+	else if (!strncmp(buf, "disable", strlen("disable")))
+		atomic_set(&fpc1020->wakeup_enabled, 0);
+	else
+		ret = -EINVAL;
+	mutex_unlock(&fpc1020->lock);
+
+	return ret;
+}
+static DEVICE_ATTR(wakeup_enable, 0200, NULL, wakeup_enable_set);
+
+/**
+ * sysf node to check the interrupt status of the sensor, the interrupt
+ * handler should perform sysf_notify to allow userland to poll the node.
+ */
+static ssize_t irq_get(struct device *dev,
+	struct device_attribute *attr,
+	char *buf)
+{
+	struct fpc1020_data *fpc1020 = dev_get_drvdata(dev);
+	int irq = gpio_get_value(fpc1020->irq_gpio);
+
+	return scnprintf(buf, PAGE_SIZE, "%i\n", irq);
+}
+
+/**
+ * writing to the irq node will just drop a printk message
+ * and return success, used for latency measurement.
+ */
+static ssize_t irq_ack(struct device *dev,
+	struct device_attribute *attr,
+	const char *buf, size_t count)
+{
+	struct fpc1020_data *fpc1020 = dev_get_drvdata(dev);
+
+	dev_dbg(fpc1020->dev, "%s\n", __func__);
+
+	return count;
+}
+static DEVICE_ATTR(irq, 0600, irq_get, irq_ack);
+
+static struct attribute *attributes[] = {
+	&dev_attr_device_prepare.attr,
+	&dev_attr_regulator_enable.attr,
+	&dev_attr_hw_reset.attr,
+	&dev_attr_wakeup_enable.attr,
+	&dev_attr_clk_enable.attr,
+	&dev_attr_irq.attr,
+	NULL
+};
+
+static const struct attribute_group attribute_group = {
+	.attrs = attributes,
+};
+
+static irqreturn_t fpc1020_irq_handler(int irq, void *handle)
+{
+	struct fpc1020_data *fpc1020 = handle;
+
+	dev_dbg(fpc1020->dev, "%s\n", __func__);
+
+	if (atomic_read(&fpc1020->wakeup_enabled)) {
+		__pm_wakeup_event(fpc1020->ttw_ws, FPC_TTW_HOLD_TIME);
+	}
+
+	sysfs_notify(&fpc1020->dev->kobj, NULL, dev_attr_irq.attr.name);
+
+	return IRQ_HANDLED;
+}
+
+static int fpc1020_request_named_gpio(struct fpc1020_data *fpc1020,
+	const char *label, int *gpio)
+{
+	struct device *dev = fpc1020->dev;
+	struct device_node *np = dev->of_node;
+	int rc = of_get_named_gpio(np, label, 0);
+
+	if (rc < 0) {
+		dev_err(dev, "failed to get '%s'\n", label);
+		return rc;
+	}
+	*gpio = rc;
+
+	rc = devm_gpio_request(dev, *gpio, label);
+	if (rc) {
+		dev_err(dev, "failed to request gpio %d\n", *gpio);
+		return rc;
+	}
+	dev_dbg(dev, "%s %d\n", label, *gpio);
+
+	return 0;
+}
+
+static int fpc1020_config_gpio(struct fpc1020_data *fpc1020)
+{
+	struct device *dev = fpc1020->dev;
+	int ret = 0;
+	// Configurate IRQ pin
+	ret = gpio_direction_input(fpc1020->irq_gpio);
+	if(ret) {
+	    dev_err(dev, "Failed to set irq GPIO\n");
+	    return ret;
+	}
+	// Configurate Reset pin
+	ret = gpio_direction_output(fpc1020->rst_gpio, 1);
+	if(ret) {
+	    dev_err(dev, "Failed to set reset pin high\n");
+	    return ret;
+	}
+
+	return 0;
+
+}
+
+static int fpc1020_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	int rc = 0;
+	int irqf;
+	struct device_node *np = dev->of_node;
+	struct fpc1020_data *fpc1020 = devm_kzalloc(dev, sizeof(*fpc1020),
+			GFP_KERNEL);
+
+	if (!fpc1020) {
+		dev_err(dev,
+			"failed to allocate memory for struct fpc1020_data\n");
+		rc = -ENOMEM;
+		goto exit;
+	}
+
+	fpc1020->dev = dev;
+	platform_set_drvdata(pdev, fpc1020);
+
+	if (!np) {
+		dev_err(dev, "no of node found\n");
+		rc = -EINVAL;
+		goto exit;
+	}
+
+	// Request IRQ and Reset pin GPIO
+	rc = fpc1020_request_named_gpio(fpc1020, "fpc,gpio_irq",
+			&fpc1020->irq_gpio);
+	if (rc)
+		goto exit;
+	rc = fpc1020_request_named_gpio(fpc1020, "fpc,gpio_rst",
+			&fpc1020->rst_gpio);
+	if (rc)
+		goto exit;
+
+	// Configure GPIO pin direction
+	rc = fpc1020_config_gpio(fpc1020);
+	if (rc)
+		goto exit;
+
+	atomic_set(&fpc1020->wakeup_enabled, 0);
+
+	irqf = IRQF_TRIGGER_RISING | IRQF_ONESHOT;
+	if (of_property_read_bool(dev->of_node, "fpc,enable-wakeup")) {
+		irqf |= IRQF_NO_SUSPEND;
+		device_init_wakeup(dev, 1);
+	}
+
+	mutex_init(&fpc1020->lock);
+	rc = devm_request_threaded_irq(dev, gpio_to_irq(fpc1020->irq_gpio),
+			NULL, fpc1020_irq_handler, irqf,
+			dev_name(dev), fpc1020);
+	if (rc) {
+		dev_err(dev, "could not request irq %d\n",
+				gpio_to_irq(fpc1020->irq_gpio));
+		goto exit;
+	}
+
+	dev_dbg(dev, "requested irq %d\n", gpio_to_irq(fpc1020->irq_gpio));
+
+	/* Request that the interrupt should be wakeable */
+	enable_irq_wake(gpio_to_irq(fpc1020->irq_gpio));
+
+	fpc1020->ttw_ws = wakeup_source_register(NULL, "fpc_ttw_ws");
+	if (!fpc1020->ttw_ws) {
+		dev_err(dev, "failed to register wakeup source\n");
+		rc = -ENODEV;
+		goto exit;
+	}
+
+	rc = sysfs_create_group(&dev->kobj, &attribute_group);
+	if (rc) {
+		dev_err(dev, "could not create sysfs\n");
+		goto exit;
+	}
+
+	if (of_property_read_bool(dev->of_node, "fpc,enable-on-boot")) {
+		dev_info(dev, "Enabling hardware\n");
+		(void)device_prepare(fpc1020, true);
+	}
+
+	rc = hw_reset(fpc1020);
+
+	dev_info(dev, "%s: ok\n", __func__);
+
+exit:
+	return rc;
+}
+
+static int fpc1020_remove(struct platform_device *pdev)
+{
+	struct fpc1020_data *fpc1020 = platform_get_drvdata(pdev);
+
+	sysfs_remove_group(&pdev->dev.kobj, &attribute_group);
+	mutex_destroy(&fpc1020->lock);
+	wakeup_source_unregister(fpc1020->ttw_ws);
+	(void)vreg_setup(fpc1020, "vdd_ana", false);
+	(void)vreg_setup(fpc1020, "vdd_io", false);
+	(void)vreg_setup(fpc1020, "vcc_spi", false);
+	dev_info(&pdev->dev, "%s\n", __func__);
+
+	return 0;
+}
+
+static struct of_device_id fpc1020_of_match[] = {
+	{ .compatible = "fpc,fpc1020", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, fpc1020_of_match);
+
+static struct platform_driver fpc1020_driver = {
+	.driver = {
+		.name	= "fpc1020",
+		.owner	= THIS_MODULE,
+		.of_match_table = fpc1020_of_match,
+	},
+	.probe	= fpc1020_probe,
+	.remove	= fpc1020_remove,
+};
+
+static int __init fpc1020_init(void)
+{
+	int rc = platform_driver_register(&fpc1020_driver);
+
+	if (!rc)
+		pr_info("%s OK\n", __func__);
+	else
+		pr_err("%s %d\n", __func__, rc);
+
+	return rc;
+}
+
+static void __exit fpc1020_exit(void)
+{
+	pr_info("%s\n", __func__);
+	platform_driver_unregister(&fpc1020_driver);
+}
+module_init(fpc1020_init);
+module_exit(fpc1020_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Aleksej Makarov");
+MODULE_AUTHOR("Henrik Tillman <henrik.tillman@fingerprints.com>");
+MODULE_DESCRIPTION("FPC1020 Fingerprint sensor device driver.");