misc: add Aschip PIR Sensor drivers

We can adjust the sensibility of the Aschip's PIR sensor via pulse gpio,
and the timing should be precise.

For example:
    min: echo 4 > /proc/pir/sensibility
    max: echo 100 > /proc/pir/sensibility

Signed-off-by: Ziyuan Xu <xzy.xu@rock-chips.com>
Change-Id: Id3e644fc38d9be24f97351df665e27fc4ff9d545

drivers/misc/Kconfig

@@ -528,6 +528,13 @@ config UID_SYS_STATS_DEBUG
 	help
 	  Per TASK based io statistics exported to /proc/uid_io
 
+config PIR_ASCHIP
+	bool "Aschip PIR(Passive Infrared Sensor)"
+	default n
+	help
+	  Provides a driver to control the sensibility of the Aschip PIR detection
+	  sensor.
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 source "drivers/misc/cb710/Kconfig"

drivers/misc/Makefile

@@ -59,3 +59,4 @@ obj-$(CONFIG_PCI_ENDPOINT_TEST)	+= pci_endpoint_test.o
 obj-$(CONFIG_OCXL)		+= ocxl/
 obj-$(CONFIG_MISC_RTSX)		+= cardreader/
 obj-$(CONFIG_UID_SYS_STATS)	+= uid_sys_stats.o
+obj-$(CONFIG_PIR_ASCHIP)	+= pir-aschip.o

drivers/misc/pir-aschip.c

@@ -0,0 +1,160 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2020 Rockchip Electronics Co. Ltd.
+ *
+ */
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+
+struct aschip_pir_drv_data {
+	struct device		*dev;
+	struct gpio_desc	*pulse_gpio;
+	struct proc_dir_entry	*procfs;
+};
+
+static int pir_aschip_set_sensibility(struct aschip_pir_drv_data *drv_data,
+				      uint32_t sensibility)
+{
+	if (sensibility > 100 || sensibility < 4) {
+		dev_err(drv_data->dev, "sensibilit should be [4, 100]\n");
+		return -EINVAL;
+	}
+
+	gpiod_set_value(drv_data->pulse_gpio, 1);
+	usleep_range(1000, 2000);
+	gpiod_set_value(drv_data->pulse_gpio, 0);
+	usleep_range(50000, 51000);
+	gpiod_set_value(drv_data->pulse_gpio, 1);
+	usleep_range(sensibility * 1000, sensibility * 1000 + 1);
+	gpiod_set_value(drv_data->pulse_gpio, 0);
+	usleep_range(50000, 51000);
+	gpiod_set_value(drv_data->pulse_gpio, 1);
+
+	return 0;
+}
+
+#ifdef CONFIG_PROC_FS
+static int pir_aschip_sensibility_show(struct seq_file *s, void *v)
+{
+	seq_puts(s, "set sensibility [4, 100] for PIR :\n");
+	seq_puts(s, "	echo [nr] > /proc/pir/sensibility\n");
+
+	return 0;
+}
+
+static int pir_aschip_sensibility_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, pir_aschip_sensibility_show, PDE_DATA(inode));
+}
+
+static ssize_t pir_aschip_sensibility_write(struct file *filp,
+					    const char __user *buf,
+					    size_t cnt, loff_t *ppos)
+{
+	struct aschip_pir_drv_data *drv_data = ((struct seq_file *)filp->private_data)->private;
+	unsigned int val;
+	int ret;
+
+	ret = kstrtouint_from_user(buf, cnt, 0, &val);
+	if (ret)
+		return ret;
+
+	ret = pir_aschip_set_sensibility(drv_data, val);
+	return ret ? ret : cnt;
+}
+
+static const struct file_operations pir_aschip_sensibility_fops = {
+	.open		= pir_aschip_sensibility_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+	.write		= pir_aschip_sensibility_write,
+};
+
+static int __init pir_aschip_create_procfs(struct aschip_pir_drv_data *drv_data)
+{
+	struct proc_dir_entry *ent;
+
+	drv_data->procfs = proc_mkdir("pir", NULL);
+	if (!drv_data->procfs)
+		return -ENOMEM;
+
+	ent = proc_create_data("sensibility", 0644, drv_data->procfs,
+			       &pir_aschip_sensibility_fops, drv_data);
+	if (!ent)
+		goto fail;
+
+	return 0;
+fail:
+	proc_remove(drv_data->procfs);
+	return -ENOMEM;
+}
+
+static void __exit pir_aschip_proc_release(struct aschip_pir_drv_data *drv_data)
+{
+	remove_proc_entry("sensibility", NULL);
+	proc_remove(drv_data->procfs);
+}
+#endif
+
+static int pir_aschip_probe(struct platform_device *pdev)
+{
+	struct aschip_pir_drv_data *drv_data;
+	struct device *dev = &pdev->dev;
+
+	drv_data = devm_kzalloc(dev, sizeof(*drv_data), GFP_KERNEL);
+	if (!drv_data)
+		return -ENOMEM;
+
+	drv_data->pulse_gpio = devm_gpiod_get(dev, "pulse", GPIOD_OUT_HIGH);
+
+	if (IS_ERR(drv_data->pulse_gpio)) {
+		dev_err(dev, "Failed to get pwdn-gpios\n");
+		return PTR_ERR(drv_data->pulse_gpio);
+	}
+
+#ifdef CONFIG_PROC_FS
+	pir_aschip_create_procfs(drv_data);
+#endif
+	drv_data->dev = dev;
+	dev_set_drvdata(dev, drv_data);
+	return 0;
+}
+
+static int pir_aschip_remove(struct platform_device *pdev)
+{
+#ifdef CONFIG_PROC_FS
+	struct aschip_pir_drv_data *drv_data;
+
+	drv_data = dev_get_drvdata(&pdev->dev);
+	pir_aschip_proc_release(drv_data);
+#endif
+	return 0;
+}
+
+static const struct of_device_id pir_aschip_rockchip_match[] = {
+	{ .compatible = "aschip,pir" },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, pir_aschip_rockchip_match);
+
+static struct platform_driver pir_aschip_pltfm_driver = {
+	.probe		= pir_aschip_probe,
+	.remove		= pir_aschip_remove,
+	.driver		= {
+		.name		= "pir_aschip_aschip",
+		.of_match_table	= pir_aschip_rockchip_match,
+	},
+};
+
+module_platform_driver(pir_aschip_pltfm_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Ziyuan Xu");
+MODULE_DESCRIPTION("Aschip PIR sensibility control driver");