Snapshot: SSC Sensor driver

This snapshot is taken as of msm-3.18 commit 95a59da3cf
(msm: hdcp: proper state sanitization for different versions)

Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>

Documentation/devicetree/bindings/qdsp/msm-ssc-sensors.txt

@@ -0,0 +1,11 @@
+* msm-ssc-sensors
+
+Required properties:
+
+ - compatible:	"qcom,msm-ssc-sensors"
+
+Example:
+
+	qcom,msm-ssc-sensors {
+		compatible = "qcom,msm-ssc-sensors";
+	};

drivers/Kconfig

@@ -202,4 +202,6 @@ source "drivers/fpga/Kconfig"
 
 source "drivers/bif/Kconfig"
 
+source "drivers/sensors/Kconfig"
+
 endmenu

drivers/Makefile

@@ -175,3 +175,5 @@ obj-$(CONFIG_NVMEM)		+= nvmem/
 obj-$(CONFIG_FPGA)		+= fpga/
 
 obj-$(CONFIG_BIF)		+= bif/
+
+obj-$(CONFIG_SENSORS_SSC)	+= sensors/

drivers/sensors/Kconfig

@@ -0,0 +1,6 @@
+config SENSORS_SSC
+	bool "Enable Sensors Driver Support for SSC"
+	help
+	  Add support for sensors SSC driver.
+	  This driver is used for exercising sensors use case,
+	  time syncing with ADSP clock.

drivers/sensors/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_SENSORS_SSC)	+= sensors_ssc.o

drivers/sensors/sensors_ssc.c

@@ -0,0 +1,396 @@
+/* Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/types.h>
+#include <linux/msm_dsps.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/cdev.h>
+#include <linux/fs.h>
+#include <linux/of_device.h>
+#include <asm/arch_timer.h>
+#include <linux/uaccess.h>
+
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/sysfs.h>
+#include <soc/qcom/subsystem_restart.h>
+
+#define IMAGE_LOAD_CMD 1
+#define IMAGE_UNLOAD_CMD 0
+#define CLASS_NAME	"ssc"
+#define DRV_NAME	"sensors"
+#define DRV_VERSION	"2.00"
+#ifdef CONFIG_COMPAT
+#define DSPS_IOCTL_READ_SLOW_TIMER32 _IOR(DSPS_IOCTL_MAGIC, 3, compat_uint_t)
+#endif
+
+struct sns_ssc_control_s {
+	struct class *dev_class;
+	dev_t dev_num;
+	struct device *dev;
+	struct cdev *cdev;
+};
+static struct sns_ssc_control_s sns_ctl;
+
+static ssize_t slpi_boot_store(struct kobject *kobj,
+	struct kobj_attribute *attr,
+	const char *buf, size_t count);
+
+struct slpi_loader_private {
+	void *pil_h;
+	struct kobject *boot_slpi_obj;
+	struct attribute_group *attr_group;
+};
+
+static struct kobj_attribute slpi_boot_attribute =
+	__ATTR(boot, 0220, NULL, slpi_boot_store);
+
+static struct attribute *attrs[] = {
+	&slpi_boot_attribute.attr,
+	NULL,
+};
+
+static struct platform_device *slpi_private;
+
+static void slpi_loader_do(struct platform_device *pdev)
+{
+
+	struct slpi_loader_private *priv = NULL;
+
+	if (!pdev) {
+		dev_err(&pdev->dev, "%s: Platform device null\n", __func__);
+		goto fail;
+	}
+
+	if (!pdev->dev.of_node) {
+		dev_err(&pdev->dev,
+			"%s: Device tree information missing\n", __func__);
+		goto fail;
+	}
+
+	priv = platform_get_drvdata(pdev);
+	if (!priv) {
+		dev_err(&pdev->dev,
+		" %s: Private data get failed\n", __func__);
+		goto fail;
+	}
+
+	priv->pil_h = subsystem_get("slpi");
+	if (IS_ERR(priv->pil_h)) {
+		dev_err(&pdev->dev, "%s: pil get failed,\n",
+			__func__);
+		goto fail;
+	}
+
+	dev_err(&pdev->dev, "%s: SLPI image is loaded\n", __func__);
+	return;
+
+fail:
+	dev_err(&pdev->dev, "%s: SLPI image loading failed\n", __func__);
+}
+
+static void slpi_loader_unload(struct platform_device *pdev)
+{
+	struct slpi_loader_private *priv = NULL;
+
+	priv = platform_get_drvdata(pdev);
+
+	if (!priv)
+		return;
+
+	if (priv->pil_h) {
+		dev_dbg(&pdev->dev, "%s: calling subsystem put\n", __func__);
+		subsystem_put(priv->pil_h);
+		priv->pil_h = NULL;
+	}
+}
+
+static ssize_t slpi_boot_store(struct kobject *kobj,
+	struct kobj_attribute *attr,
+	const char *buf,
+	size_t count)
+{
+	int boot = 0;
+
+	if (sscanf(buf, "%du", &boot) != 1)
+		return -EINVAL;
+
+	if (boot == IMAGE_LOAD_CMD) {
+		pr_debug("%s: going to call slpi_loader_do\n", __func__);
+		slpi_loader_do(slpi_private);
+	} else if (boot == IMAGE_UNLOAD_CMD) {
+		pr_debug("%s: going to call slpi_unloader\n", __func__);
+		slpi_loader_unload(slpi_private);
+	}
+	return count;
+}
+
+static int slpi_loader_init_sysfs(struct platform_device *pdev)
+{
+	int ret = -EINVAL;
+	struct slpi_loader_private *priv = NULL;
+
+	slpi_private = NULL;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv) {
+		ret = -ENOMEM;
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	priv->pil_h = NULL;
+	priv->boot_slpi_obj = NULL;
+	priv->attr_group = devm_kzalloc(&pdev->dev,
+				sizeof(*(priv->attr_group)),
+				GFP_KERNEL);
+	if (!priv->attr_group) {
+		dev_err(&pdev->dev, "%s: malloc attr_group failed\n",
+						__func__);
+		ret = -ENOMEM;
+		goto error_return;
+	}
+
+	priv->attr_group->attrs = attrs;
+
+	priv->boot_slpi_obj = kobject_create_and_add("boot_slpi", kernel_kobj);
+	if (!priv->boot_slpi_obj) {
+		dev_err(&pdev->dev, "%s: sysfs create and add failed\n",
+						__func__);
+		ret = -ENOMEM;
+		goto error_return;
+	}
+
+	ret = sysfs_create_group(priv->boot_slpi_obj, priv->attr_group);
+	if (ret) {
+		dev_err(&pdev->dev, "%s: sysfs create group failed %d\n",
+							__func__, ret);
+		goto error_return;
+	}
+
+	slpi_private = pdev;
+
+	return 0;
+
+error_return:
+
+	if (priv->boot_slpi_obj) {
+		kobject_del(priv->boot_slpi_obj);
+		priv->boot_slpi_obj = NULL;
+	}
+
+	return ret;
+}
+
+static int slpi_loader_remove(struct platform_device *pdev)
+{
+	struct slpi_loader_private *priv = NULL;
+
+	priv = platform_get_drvdata(pdev);
+
+	if (!priv)
+		return 0;
+
+	if (priv->pil_h) {
+		subsystem_put(priv->pil_h);
+		priv->pil_h = NULL;
+	}
+
+	if (priv->boot_slpi_obj) {
+		sysfs_remove_group(priv->boot_slpi_obj, priv->attr_group);
+		kobject_del(priv->boot_slpi_obj);
+		priv->boot_slpi_obj = NULL;
+	}
+
+	return 0;
+}
+
+/*
+ * Read QTimer clock ticks and scale down to 32KHz clock as used
+ * in DSPS
+ */
+static u32 sns_read_qtimer(void)
+{
+	u64 val;
+	val = arch_counter_get_cntpct();
+	/*
+	 * To convert ticks from 19.2 Mhz clock to 32768 Hz clock:
+	 * x = (value * 32768) / 19200000
+	 * This is same as first left shift the value by 4 bits, i.e. mutiply
+	 * by 16, and then divide by 9375. The latter is preferable since
+	 * QTimer tick (value) is 56-bit, so (value * 32768) could overflow,
+	 * while (value * 16) will never do
+	 */
+	val <<= 4;
+	do_div(val, 9375);
+
+	return (u32)val;
+}
+
+static int sensors_ssc_open(struct inode *ip, struct file *fp)
+{
+	return 0;
+}
+
+static int sensors_ssc_release(struct inode *inode, struct file *file)
+{
+	return 0;
+}
+
+static long sensors_ssc_ioctl(struct file *file,
+			unsigned int cmd, unsigned long arg)
+{
+	int ret = 0;
+	u32 val = 0;
+
+	switch (cmd) {
+	case DSPS_IOCTL_READ_SLOW_TIMER:
+#ifdef CONFIG_COMPAT
+	case DSPS_IOCTL_READ_SLOW_TIMER32:
+#endif
+		val = sns_read_qtimer();
+		ret = put_user(val, (u32 __user *) arg);
+		break;
+
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+const struct file_operations sensors_ssc_fops = {
+	.owner = THIS_MODULE,
+	.open = sensors_ssc_open,
+	.release = sensors_ssc_release,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = sensors_ssc_ioctl,
+#endif
+	.unlocked_ioctl = sensors_ssc_ioctl
+};
+
+static int sensors_ssc_probe(struct platform_device *pdev)
+{
+	int ret = slpi_loader_init_sysfs(pdev);
+
+	if (ret != 0) {
+		dev_err(&pdev->dev, "%s: Error in initing sysfs\n", __func__);
+		return ret;
+	}
+
+	sns_ctl.dev_class = class_create(THIS_MODULE, CLASS_NAME);
+	if (sns_ctl.dev_class == NULL) {
+		pr_err("%s: class_create fail.\n", __func__);
+		goto res_err;
+	}
+
+	ret = alloc_chrdev_region(&sns_ctl.dev_num, 0, 1, DRV_NAME);
+	if (ret) {
+		pr_err("%s: alloc_chrdev_region fail.\n", __func__);
+		goto alloc_chrdev_region_err;
+	}
+
+	sns_ctl.dev = device_create(sns_ctl.dev_class, NULL,
+				     sns_ctl.dev_num,
+				     &sns_ctl, DRV_NAME);
+	if (IS_ERR(sns_ctl.dev)) {
+		pr_err("%s: device_create fail.\n", __func__);
+		goto device_create_err;
+	}
+
+	sns_ctl.cdev = cdev_alloc();
+	if (sns_ctl.cdev == NULL) {
+		pr_err("%s: cdev_alloc fail.\n", __func__);
+		goto cdev_alloc_err;
+	}
+	cdev_init(sns_ctl.cdev, &sensors_ssc_fops);
+	sns_ctl.cdev->owner = THIS_MODULE;
+
+	ret = cdev_add(sns_ctl.cdev, sns_ctl.dev_num, 1);
+	if (ret) {
+		pr_err("%s: cdev_add fail.\n", __func__);
+		goto cdev_add_err;
+	}
+
+	return 0;
+
+cdev_add_err:
+	kfree(sns_ctl.cdev);
+cdev_alloc_err:
+	device_destroy(sns_ctl.dev_class, sns_ctl.dev_num);
+device_create_err:
+	unregister_chrdev_region(sns_ctl.dev_num, 1);
+alloc_chrdev_region_err:
+	class_destroy(sns_ctl.dev_class);
+res_err:
+	return -ENODEV;
+}
+
+static int sensors_ssc_remove(struct platform_device *pdev)
+{
+	slpi_loader_remove(pdev);
+	cdev_del(sns_ctl.cdev);
+	kfree(sns_ctl.cdev);
+	sns_ctl.cdev = NULL;
+	device_destroy(sns_ctl.dev_class, sns_ctl.dev_num);
+	unregister_chrdev_region(sns_ctl.dev_num, 1);
+	class_destroy(sns_ctl.dev_class);
+
+	return 0;
+}
+
+static const struct of_device_id msm_ssc_sensors_dt_match[] = {
+	{.compatible = "qcom,msm-ssc-sensors"},
+	{},
+};
+MODULE_DEVICE_TABLE(of, msm_ssc_sensors_dt_match);
+
+static struct platform_driver sensors_ssc_driver = {
+	.driver = {
+		.name = "sensors-ssc",
+		.owner = THIS_MODULE,
+		.of_match_table = msm_ssc_sensors_dt_match,
+	},
+	.probe = sensors_ssc_probe,
+	.remove = sensors_ssc_remove,
+};
+
+static int __init sensors_ssc_init(void)
+{
+	int rc;
+
+	pr_debug("%s driver version %s.\n", DRV_NAME, DRV_VERSION);
+	rc = platform_driver_register(&sensors_ssc_driver);
+	if (rc) {
+		pr_err("%s: Failed to register sensors ssc driver\n",
+			__func__);
+		return rc;
+	}
+
+	return 0;
+}
+
+static void __exit sensors_ssc_exit(void)
+{
+	platform_driver_unregister(&sensors_ssc_driver);
+}
+
+module_init(sensors_ssc_init);
+module_exit(sensors_ssc_exit);
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Sensors SSC driver");

include/uapi/linux/Kbuild

@@ -470,3 +470,4 @@ header-y += xilinx-v4l2-controls.h
 header-y += zorro.h
 header-y += zorro_ids.h
 header-y += userfaultfd.h
+header-y += msm_dsps.h

include/uapi/linux/msm_dsps.h

@@ -0,0 +1,16 @@
+#ifndef _UAPI_DSPS_H_
+#define _UAPI_DSPS_H_
+
+#include <linux/ioctl.h>
+
+#define DSPS_IOCTL_MAGIC 'd'
+
+#define DSPS_IOCTL_ON	_IO(DSPS_IOCTL_MAGIC, 1)
+#define DSPS_IOCTL_OFF	_IO(DSPS_IOCTL_MAGIC, 2)
+
+#define DSPS_IOCTL_READ_SLOW_TIMER _IOR(DSPS_IOCTL_MAGIC, 3, unsigned int*)
+#define DSPS_IOCTL_READ_FAST_TIMER _IOR(DSPS_IOCTL_MAGIC, 4, unsigned int*)
+
+#define DSPS_IOCTL_RESET _IO(DSPS_IOCTL_MAGIC, 5)
+
+#endif	/* _UAPI_DSPS_H_ */