iio: staging: adc: palmas: Support for auto conversion shutdown

Support for auto conversion shutdown when auto conversion result is
crossed threshold.
Corrected auto conversion period calculation.
Restore CH3 current source if CH3 is dual current mode.
Added debugfs for auto conversion.

Bug 1398960
Bug 1415280

Change-Id: I148c51ab70dcca756f74a5cb8ab10112de3a9f03
Signed-off-by: Jinyoung Park <jinyoungp@nvidia.com>
Reviewed-on: http://git-master/r/360669
Reviewed-by: Harry Hong <hhong@nvidia.com>
Tested-by: Harry Hong <hhong@nvidia.com>

1 files changed, 190 insertions, 28 deletions

diff --git a/drivers/staging/iio/adc/palmas_gpadc.c b/drivers/staging/iio/adc/palmas_gpadc.c
index 34e5ae932e98..fb4f59236957 100644
--- a/drivers/staging/iio/adc/palmas_gpadc.c
+++ b/drivers/staging/iio/adc/palmas_gpadc.c
@@ -25,11 +25,13 @@
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
+#include <linux/uaccess.h>
 #include <linux/delay.h>
 #include <linux/i2c.h>
 #include <linux/pm.h>
 #include <linux/mfd/palmas.h>
 #include <linux/completion.h>
+#include <linux/debugfs.h>
 
 #include "../iio.h"
 #include "../driver.h"
@@ -97,6 +99,8 @@ struct palmas_gpadc {
 	bool				auto_conv0_enable;
 	bool				auto_conv1_enable;
 	int				auto_conversion_period;
+
+	struct dentry			*dentry;
 };
 
 /*
@@ -182,6 +186,9 @@ static int palmas_gpadc_auto_conv_configure(struct palmas_gpadc *adc)
 	int thres;
 	int ret;
 
+	if (!adc->auto_conv0_enable && !adc->auto_conv1_enable)
+		return 0;
+
 	adc_period = adc->auto_conversion_period;
 	for (i = 0; i < 16; ++i) {
 		if (((1000 * (1 << i))/32) > adc_period)
@@ -291,6 +298,9 @@ static int palmas_gpadc_auto_conv_reset(struct palmas_gpadc *adc)
 {
 	int ret;
 
+	if (!adc->auto_conv0_enable && !adc->auto_conv1_enable)
+		return 0;
+
 	ret = palmas_write(adc->palmas, PALMAS_GPADC_BASE,
 			PALMAS_GPADC_AUTO_SELECT, 0);
 	if (ret < 0) {
@@ -304,16 +314,6 @@ static int palmas_gpadc_auto_conv_reset(struct palmas_gpadc *adc)
 		return ret;
 	}
 
-	if (adc->auto_conv0_data.adc_shutdown ||
-			adc->auto_conv1_data.adc_shutdown) {
-		ret = palmas_gpadc_auto_conv_configure(adc);
-		if (ret < 0) {
-			dev_err(adc->dev,
-				"auto conversion configure failed: %d\n", ret);
-			return ret;
-		}
-	}
-
 	return 0;
 }
 
@@ -427,7 +427,16 @@ static int palmas_gpadc_enable(struct palmas_gpadc *adc, int adc_chan,
 				<< PALMAS_GPADC_CTRL1_CURRENT_SRC_CH3_SHIFT);
 		}
 
+		mask = val = 0;
 		mask |= PALMAS_GPADC_CTRL1_GPADC_FORCE;
+
+		/* Restore CH3 current source if CH3 is dual current mode. */
+		if ((adc_chan == PALMAS_ADC_CH_IN3) && adc->ch3_dual_current) {
+			mask |= PALMAS_GPADC_CTRL1_CURRENT_SRC_CH3_MASK;
+			val |= (adc->ch3_current
+				<< PALMAS_GPADC_CTRL1_CURRENT_SRC_CH3_SHIFT);
+		}
+
 		ret = palmas_update_bits(adc->palmas, PALMAS_GPADC_BASE,
 					 PALMAS_GPADC_CTRL1, mask, val);
 		if (ret < 0) {
@@ -592,6 +601,171 @@ out_unlock:
 	return ret;
 }
 
+#ifdef CONFIG_DEBUG_FS
+static int auto_conv_period_get(void *data, u64 *val)
+{
+	struct palmas_gpadc *adc = (struct palmas_gpadc *)data;
+
+	*val = adc->auto_conversion_period;
+	return 0;
+}
+
+static int auto_conv_period_set(void *data, u64 val)
+{
+	struct palmas_gpadc *adc = (struct palmas_gpadc *)data;
+	struct iio_dev *iodev = dev_get_drvdata(adc->dev);
+
+	adc->auto_conversion_period = val;
+
+	mutex_lock(&iodev->mlock);
+	palmas_gpadc_auto_conv_reset(adc);
+	palmas_gpadc_auto_conv_configure(adc);
+	mutex_unlock(&iodev->mlock);
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(auto_conv_period_fops, auto_conv_period_get,
+			auto_conv_period_set, "%llu\n");
+
+static ssize_t auto_conv_data_read(struct file *file,
+			char __user *user_buf, size_t count, loff_t *ppos)
+{
+	struct palmas_gpadc *adc = file->private_data;
+	unsigned char *d_iname;
+	char buf[64] = { 0, };
+	ssize_t ret = 0;
+
+	d_iname = file->f_path.dentry->d_iname;
+
+	if (!strcmp("auto_conv0_channel", d_iname)) {
+		ret = snprintf(buf, sizeof(buf), "%d\n",
+				adc->auto_conv0_data.adc_channel_number);
+	} else if (!strcmp("auto_conv1_channel", d_iname)) {
+		ret = snprintf(buf, sizeof(buf), "%d\n",
+				adc->auto_conv1_data.adc_channel_number);
+	} else if (!strcmp("auto_conv0_high_threshold", d_iname)) {
+		ret = snprintf(buf, sizeof(buf), "%d\n",
+				adc->auto_conv0_data.adc_high_threshold);
+	} else if  (!strcmp("auto_conv1_high_threshold", d_iname)) {
+		ret = snprintf(buf, sizeof(buf), "%d\n",
+				adc->auto_conv1_data.adc_high_threshold);
+	} else if (!strcmp("auto_conv0_low_threshold", d_iname)) {
+		ret = snprintf(buf, sizeof(buf), "%d\n",
+				adc->auto_conv0_data.adc_low_threshold);
+	} else if (!strcmp("auto_conv1_low_threshold", d_iname)) {
+		ret = snprintf(buf, sizeof(buf), "%d\n",
+				adc->auto_conv1_data.adc_low_threshold);
+	} else if (!strcmp("auto_conv0_shutdown", d_iname)) {
+		ret = snprintf(buf, sizeof(buf), "%d\n",
+				adc->auto_conv0_data.adc_shutdown);
+	} else if (!strcmp("auto_conv1_shutdown", d_iname)) {
+		ret = snprintf(buf, sizeof(buf), "%d\n",
+				adc->auto_conv1_data.adc_shutdown);
+	}
+
+	return simple_read_from_buffer(user_buf, count, ppos, buf, ret);
+}
+
+static ssize_t auto_conv_data_write(struct file *file,
+			const char __user *user_buf, size_t count, loff_t *ppos)
+{
+	struct palmas_gpadc *adc = file->private_data;
+	struct iio_dev *iodev = dev_get_drvdata(adc->dev);
+	unsigned char *d_iname;
+	char buf[64] = { 0, };
+	int val;
+	ssize_t buf_size;
+
+	buf_size = min(count, (sizeof(buf)-1));
+	if (copy_from_user(buf, user_buf, buf_size))
+		return -EFAULT;
+
+	if (!sscanf(buf, "%d\n", &val))
+		return -EINVAL;
+
+	d_iname = file->f_path.dentry->d_iname;
+
+	if (!strcmp("auto_conv0_channel", d_iname)) {
+		adc->auto_conv0_data.adc_channel_number = val;
+	} else if (!strcmp("auto_conv1_channel", d_iname)) {
+		adc->auto_conv1_data.adc_channel_number = val;
+	} else if (!strcmp("auto_conv0_high_threshold", d_iname)) {
+		adc->auto_conv0_data.adc_high_threshold = val;
+		if (val > 0)
+			adc->auto_conv0_data.adc_low_threshold = 0;
+	} else if  (!strcmp("auto_conv1_high_threshold", d_iname)) {
+		adc->auto_conv1_data.adc_high_threshold = val;
+		if (val > 0)
+			adc->auto_conv1_data.adc_low_threshold = 0;
+	} else if (!strcmp("auto_conv0_low_threshold", d_iname)) {
+		adc->auto_conv0_data.adc_low_threshold = val;
+		if (val > 0)
+			adc->auto_conv0_data.adc_high_threshold = 0;
+	} else if (!strcmp("auto_conv1_low_threshold", d_iname)) {
+		adc->auto_conv1_data.adc_low_threshold = val;
+		if (val > 0)
+			adc->auto_conv1_data.adc_high_threshold = 0;
+	} else if (!strcmp("auto_conv0_shutdown", d_iname)) {
+		adc->auto_conv0_data.adc_shutdown = val;
+	} else if (!strcmp("auto_conv1_shutdown", d_iname)) {
+		adc->auto_conv1_data.adc_shutdown = val;
+	}
+
+	mutex_lock(&iodev->mlock);
+	palmas_gpadc_auto_conv_reset(adc);
+	palmas_gpadc_auto_conv_configure(adc);
+	mutex_unlock(&iodev->mlock);
+	return buf_size;
+}
+
+static const struct file_operations auto_conv_data_fops = {
+	.open		= simple_open,
+	.write		= auto_conv_data_write,
+	.read		= auto_conv_data_read,
+};
+
+static void palmas_gpadc_debugfs_init(struct palmas_gpadc *adc)
+{
+	adc->dentry = debugfs_create_dir(dev_name(adc->dev), NULL);
+	if (!adc->dentry) {
+		dev_err(adc->dev, "%s: failed to create debugfs dir\n",
+			__func__);
+		return;
+	}
+
+	if (adc->auto_conv0_enable || adc->auto_conv1_enable)
+		debugfs_create_file("auto_conv_period", 0644,
+				    adc->dentry, adc,
+				    &auto_conv_period_fops);
+
+	if (adc->auto_conv0_enable) {
+		debugfs_create_file("auto_conv0_channel", 0644,
+				    adc->dentry, adc, &auto_conv_data_fops);
+		debugfs_create_file("auto_conv0_high_threshold", 0644,
+				    adc->dentry, adc, &auto_conv_data_fops);
+		debugfs_create_file("auto_conv0_low_threshold", 0644,
+				    adc->dentry, adc, &auto_conv_data_fops);
+		debugfs_create_file("auto_conv0_shutdown", 0644,
+				    adc->dentry, adc, &auto_conv_data_fops);
+	}
+
+	if (adc->auto_conv1_enable) {
+		debugfs_create_file("auto_conv1_channel", 0644,
+				    adc->dentry, adc, &auto_conv_data_fops);
+		debugfs_create_file("auto_conv1_high_threshold", 0644,
+				    adc->dentry, adc, &auto_conv_data_fops);
+		debugfs_create_file("auto_conv1_low_threshold", 0644,
+				    adc->dentry, adc, &auto_conv_data_fops);
+		debugfs_create_file("auto_conv1_shutdown", 0644,
+				    adc->dentry, adc, &auto_conv_data_fops);
+	}
+}
+#else
+static void palmas_gpadc_debugfs_init(struct palmas_gpadc *adc)
+{
+}
+#endif /*  CONFIG_DEBUG_FS */
+
 static const struct iio_info palmas_gpadc_iio_info = {
 	.read_raw = &palmas_gpadc_read_raw,
 	.driver_module = THIS_MODULE,
@@ -758,16 +932,13 @@ static int __devinit palmas_gpadc_probe(struct platform_device *pdev)
 	if (adc->auto_conv0_enable || adc->auto_conv1_enable)
 		device_wakeup_enable(&pdev->dev);
 
-	if (adc->auto_conv0_data.adc_shutdown ||
-			adc->auto_conv1_data.adc_shutdown) {
-		ret = palmas_gpadc_auto_conv_configure(adc);
-		if (ret < 0) {
-			dev_err(adc->dev,
-				"auto conversion configure failed: %d\n", ret);
-			goto out_irq_auto1_free;
-		}
+	ret = palmas_gpadc_auto_conv_configure(adc);
+	if (ret < 0) {
+		dev_err(adc->dev, "auto_conv_configure() failed: %d\n", ret);
+		goto out_irq_auto1_free;
 	}
 
+	palmas_gpadc_debugfs_init(adc);
 	return 0;
 
 out_irq_auto1_free:
@@ -792,6 +963,7 @@ static int __devexit palmas_gpadc_remove(struct platform_device *pdev)
 	struct palmas_gpadc *adc = iio_priv(iodev);
 	struct palmas_platform_data *pdata = dev_get_platdata(pdev->dev.parent);
 
+	debugfs_remove_recursive(adc->dentry);
 	if (pdata->adc_pdata->iio_maps)
 		iio_map_array_unregister(iodev, pdata->adc_pdata->iio_maps);
 	iio_device_unregister(iodev);
@@ -810,15 +982,10 @@ static int palmas_gpadc_suspend(struct device *dev)
 	struct iio_dev *iodev = dev_get_drvdata(dev);
 	struct palmas_gpadc *adc = iio_priv(iodev);
 	int wakeup = adc->auto_conv0_enable || adc->auto_conv1_enable;
-	int ret;
 
 	if (!device_may_wakeup(dev) || !wakeup)
 		return 0;
 
-	ret = palmas_gpadc_auto_conv_configure(adc);
-	if (ret < 0)
-		return ret;
-
 	if (adc->auto_conv0_enable)
 		enable_irq_wake(adc->irq_auto_0);
 
@@ -833,15 +1000,10 @@ static int palmas_gpadc_resume(struct device *dev)
 	struct iio_dev *iodev = dev_get_drvdata(dev);
 	struct palmas_gpadc *adc = iio_priv(iodev);
 	int wakeup = adc->auto_conv0_enable || adc->auto_conv1_enable;
-	int ret;
 
 	if (!device_may_wakeup(dev) || !wakeup)
 		return 0;
 
-	ret = palmas_gpadc_auto_conv_reset(adc);
-	if (ret < 0)
-		return ret;
-
 	if (adc->auto_conv0_enable)
 		disable_irq_wake(adc->irq_auto_0);