drivers: misc: therm_est: add debug sysfs nodes

Added the ability change coefficients and offset during runtime.
This is found in /sys/devices/therm_est/coeffs and
/sys/devices/therm_est/offset.

Also, added the ability to view the history of temperatures
per device used by the therm_est driver. This is found in
/sys/devices/therm_est/temps.

bug 1158994
bug 1059470

Change-Id: Ie3441a2c9a613381d4e19c61479001975488fd76
Signed-off-by: Joshua Primero <jprimero@nvidia.com>
Reviewed-on: http://git-master/r/145060
(cherry picked from commit ee1078d1262fd0f01d156796837c3c67f92d3873)
Signed-off-by: Gaurav Batra <gbatra@nvidia.com>
Reviewed-on: http://git-master/r/147060

Rebase-Id: Rf68a5473fa9ebe40ff38c8337689b0b14ea04f63

1 files changed, 126 insertions, 0 deletions

diff --git a/drivers/misc/therm_est.c b/drivers/misc/therm_est.c
index 0bef8fbb7..8e6ace29f 100644
--- a/drivers/misc/therm_est.c
+++ b/drivers/misc/therm_est.c
@@ -30,6 +30,7 @@
 #include <linux/therm_est.h>
 #include <linux/thermal.h>
 #include <linux/module.h>
+#include <linux/hwmon-sysfs.h>
 
 struct therm_estimator {
         long cur_temp;
@@ -139,6 +140,128 @@ static struct thermal_zone_device_ops therm_est_ops = {
         .get_temp = therm_est_get_temp,
 };
 
+static ssize_t show_coeff(struct device *dev,
+                                struct device_attribute *da,
+                                char *buf)
+{
+        struct therm_estimator *est = dev_get_drvdata(dev);
+        ssize_t len, total_len = 0;
+        int i, j;
+        for (i = 0; i < est->ndevs; i++) {
+                len = snprintf(buf + total_len, PAGE_SIZE, "[%d]", i);
+                total_len += len;
+                for (j = 0; j < HIST_LEN; j++) {
+                        len = snprintf(buf + total_len, PAGE_SIZE, " %ld",
+                                        est->devs[i].coeffs[j]);
+                        total_len += len;
+                }
+                len = snprintf(buf + total_len, PAGE_SIZE, "\n");
+                total_len += len;
+        }
+        return strlen(buf);
+}
+
+static ssize_t set_coeff(struct device *dev,
+                                struct device_attribute *da,
+                                const char *buf, size_t count)
+{
+        struct therm_estimator *est = dev_get_drvdata(dev);
+        int devid, scount;
+        long coeff[20];
+
+        if (HIST_LEN > 20)
+                return -EINVAL;
+
+        scount = sscanf(buf, "[%d] %ld %ld %ld %ld %ld %ld %ld %ld %ld %ld " \
+                        "%ld %ld %ld %ld %ld %ld %ld %ld %ld %ld",
+                        &devid,
+                        &coeff[0],
+                        &coeff[1],
+                        &coeff[2],
+                        &coeff[3],
+                        &coeff[4],
+                        &coeff[5],
+                        &coeff[6],
+                        &coeff[7],
+                        &coeff[8],
+                        &coeff[9],
+                        &coeff[10],
+                        &coeff[11],
+                        &coeff[12],
+                        &coeff[13],
+                        &coeff[14],
+                        &coeff[15],
+                        &coeff[16],
+                        &coeff[17],
+                        &coeff[18],
+                        &coeff[19]);
+
+        if (scount != HIST_LEN + 1)
+                return -1;
+
+        if (devid < 0 || devid >= est->ndevs)
+                return -EINVAL;
+
+        /* This has obvious locking issues but don't worry about it */
+        memcpy(est->devs[devid].coeffs, coeff, sizeof(long) * HIST_LEN);
+
+        return count;
+}
+
+static ssize_t show_offset(struct device *dev,
+                                struct device_attribute *da,
+                                char *buf)
+{
+        struct therm_estimator *est = dev_get_drvdata(dev);
+        snprintf(buf, PAGE_SIZE, "%ld\n", est->toffset);
+        return strlen(buf);
+}
+
+static ssize_t set_offset(struct device *dev,
+                                struct device_attribute *da,
+                                const char *buf, size_t count)
+{
+        struct therm_estimator *est = dev_get_drvdata(dev);
+        int offset;
+
+        if (kstrtoint(buf, 0, &offset))
+                return -EINVAL;
+
+        est->toffset = offset;
+
+        return count;
+}
+
+static ssize_t show_temps(struct device *dev,
+                                struct device_attrbite *da,
+                                char *buf)
+{
+        struct therm_estimator *est = dev_get_drvdata(dev);
+        ssize_t total_len = 0;
+        int i, j;
+        int index;
+
+        /* This has obvious locking issues but don't worry about it */
+        for (i = 0; i < est->ndevs; i++) {
+                total_len += snprintf(buf + total_len, PAGE_SIZE, "[%d]", i);
+                for (j = 0; j < HIST_LEN; j++) {
+                        index = (est->ntemp - j + HIST_LEN) % HIST_LEN;
+                        total_len += snprintf(buf + total_len,
+                                                PAGE_SIZE,
+                                                " %ld",
+                                                est->devs[i].hist[index]);
+                }
+                total_len += snprintf(buf + total_len, PAGE_SIZE, "\n");
+        }
+        return strlen(buf);
+}
+
+static struct sensor_device_attribute therm_est_nodes[] = {
+        SENSOR_ATTR(coeff, S_IRUGO | S_IWUSR, show_coeff, set_coeff, 0),
+        SENSOR_ATTR(offset, S_IRUGO | S_IWUSR, show_offset, set_offset, 0),
+        SENSOR_ATTR(temps, S_IRUGO, show_temps, 0, 0),
+};
+
 static int __devinit therm_est_probe(struct platform_device *pdev)
 {
         int i, j;
@@ -193,6 +316,9 @@ static int __devinit therm_est_probe(struct platform_device *pdev)
         if (IS_ERR_OR_NULL(est->thz))
                 goto err;
 
+        for (i = 0; i < ARRAY_SIZE(therm_est_nodes); i++)
+                device_create_file(&pdev->dev, &therm_est_nodes[i].dev_attr);
+
         return 0;
 err:
         kfree(est);