mirror of https://github.com/hak5/openwrt.git
207 lines
6.1 KiB
Diff
207 lines
6.1 KiB
Diff
From 83a8df1b7fff284fc3c2277c8051f53acde2e64f Mon Sep 17 00:00:00 2001
|
|
From: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= <noralf@tronnes.org>
|
|
Date: Sat, 24 Feb 2018 13:41:25 +0100
|
|
Subject: [PATCH 234/454] firmware/raspberrypi: Add a get_throttled sysfs file
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=UTF-8
|
|
Content-Transfer-Encoding: 8bit
|
|
|
|
Under-voltage due to inadequate power supplies is a recurring problem for
|
|
new Raspberry Pi users. There are visual indications that an
|
|
under-voltage situation is occuring like blinking power led and a
|
|
lightning icon on the desktop (not shown when using the vc4 driver), but
|
|
for new users it's not obvious that this signifies a critical situation.
|
|
|
|
This patch provides a twofold improvement to the situation:
|
|
|
|
Firstly it logs under-voltage events to the kernel log. This provides
|
|
information also for headless installations.
|
|
|
|
Secondly it provides a sysfs file to read the value. This improves on
|
|
'vcgencmd' by providing change notification. Userspace can poll on the
|
|
file and be notified of changes to the value.
|
|
A script can poll the file and use dbus notification to put a windows on
|
|
the desktop with information about the severity with a recommendation to
|
|
change the power supply. A link to more information can also be provided.
|
|
Only changes to the sticky bits are reported (cleared between readings).
|
|
|
|
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
|
|
---
|
|
drivers/firmware/raspberrypi.c | 108 +++++++++++++++++++++
|
|
include/soc/bcm2835/raspberrypi-firmware.h | 1 +
|
|
2 files changed, 109 insertions(+)
|
|
|
|
--- a/drivers/firmware/raspberrypi.c
|
|
+++ b/drivers/firmware/raspberrypi.c
|
|
@@ -14,6 +14,7 @@
|
|
#include <linux/module.h>
|
|
#include <linux/of_platform.h>
|
|
#include <linux/platform_device.h>
|
|
+#include <linux/workqueue.h>
|
|
#include <soc/bcm2835/raspberrypi-firmware.h>
|
|
|
|
#define MBOX_MSG(chan, data28) (((data28) & ~0xf) | ((chan) & 0xf))
|
|
@@ -21,11 +22,14 @@
|
|
#define MBOX_DATA28(msg) ((msg) & ~0xf)
|
|
#define MBOX_CHAN_PROPERTY 8
|
|
|
|
+#define UNDERVOLTAGE_BIT BIT(0)
|
|
+
|
|
struct rpi_firmware {
|
|
struct mbox_client cl;
|
|
struct mbox_chan *chan; /* The property channel. */
|
|
struct completion c;
|
|
u32 enabled;
|
|
+ struct delayed_work get_throttled_poll_work;
|
|
};
|
|
|
|
static struct platform_device *g_pdev;
|
|
@@ -166,6 +170,101 @@ int rpi_firmware_property(struct rpi_fir
|
|
}
|
|
EXPORT_SYMBOL_GPL(rpi_firmware_property);
|
|
|
|
+static int rpi_firmware_get_throttled(struct rpi_firmware *fw, u32 *value)
|
|
+{
|
|
+ static ktime_t old_timestamp;
|
|
+ static u32 old_value;
|
|
+ u32 new_sticky, old_sticky, new_uv, old_uv;
|
|
+ ktime_t new_timestamp;
|
|
+ s64 elapsed_ms;
|
|
+ int ret;
|
|
+
|
|
+ if (!fw)
|
|
+ return -EBUSY;
|
|
+
|
|
+ /*
|
|
+ * We can't run faster than the sticky shift (100ms) since we get
|
|
+ * flipping in the sticky bits that are cleared.
|
|
+ * This happens on polling, so just return the previous value.
|
|
+ */
|
|
+ new_timestamp = ktime_get();
|
|
+ elapsed_ms = ktime_ms_delta(new_timestamp, old_timestamp);
|
|
+ if (elapsed_ms < 150) {
|
|
+ *value = old_value;
|
|
+ return 0;
|
|
+ }
|
|
+ old_timestamp = new_timestamp;
|
|
+
|
|
+ /* Clear sticky bits */
|
|
+ *value = 0xffff;
|
|
+
|
|
+ ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_THROTTLED,
|
|
+ value, sizeof(*value));
|
|
+ if (ret)
|
|
+ return ret;
|
|
+
|
|
+ new_sticky = *value >> 16;
|
|
+ old_sticky = old_value >> 16;
|
|
+ old_value = *value;
|
|
+
|
|
+ /* Only notify about changes in the sticky bits */
|
|
+ if (new_sticky == old_sticky)
|
|
+ return 0;
|
|
+
|
|
+ new_uv = new_sticky & UNDERVOLTAGE_BIT;
|
|
+ old_uv = old_sticky & UNDERVOLTAGE_BIT;
|
|
+
|
|
+ if (new_uv != old_uv) {
|
|
+ if (new_uv)
|
|
+ pr_crit("Under-voltage detected! (0x%08x)\n", *value);
|
|
+ else
|
|
+ pr_info("Voltage normalised (0x%08x)\n", *value);
|
|
+ }
|
|
+
|
|
+ sysfs_notify(&fw->cl.dev->kobj, NULL, "get_throttled");
|
|
+
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+static void get_throttled_poll(struct work_struct *work)
|
|
+{
|
|
+ struct rpi_firmware *fw = container_of(work, struct rpi_firmware,
|
|
+ get_throttled_poll_work.work);
|
|
+ u32 dummy;
|
|
+ int ret;
|
|
+
|
|
+ ret = rpi_firmware_get_throttled(fw, &dummy);
|
|
+ if (ret)
|
|
+ pr_debug("%s: Failed to read value (%d)", __func__, ret);
|
|
+
|
|
+ schedule_delayed_work(&fw->get_throttled_poll_work, 2 * HZ);
|
|
+}
|
|
+
|
|
+static ssize_t get_throttled_show(struct device *dev,
|
|
+ struct device_attribute *attr, char *buf)
|
|
+{
|
|
+ struct rpi_firmware *fw = dev_get_drvdata(dev);
|
|
+ u32 value;
|
|
+ int ret;
|
|
+
|
|
+ ret = rpi_firmware_get_throttled(fw, &value);
|
|
+ if (ret)
|
|
+ return ret;
|
|
+
|
|
+ return sprintf(buf, "%x\n", value);
|
|
+}
|
|
+
|
|
+static DEVICE_ATTR_RO(get_throttled);
|
|
+
|
|
+static struct attribute *rpi_firmware_dev_attrs[] = {
|
|
+ &dev_attr_get_throttled.attr,
|
|
+ NULL,
|
|
+};
|
|
+
|
|
+static const struct attribute_group rpi_firmware_dev_group = {
|
|
+ .attrs = rpi_firmware_dev_attrs,
|
|
+};
|
|
+
|
|
static void
|
|
rpi_firmware_print_firmware_revision(struct rpi_firmware *fw)
|
|
{
|
|
@@ -190,6 +289,11 @@ static int rpi_firmware_probe(struct pla
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
struct rpi_firmware *fw;
|
|
+ int ret;
|
|
+
|
|
+ ret = devm_device_add_group(dev, &rpi_firmware_dev_group);
|
|
+ if (ret)
|
|
+ return ret;
|
|
|
|
fw = devm_kzalloc(dev, sizeof(*fw), GFP_KERNEL);
|
|
if (!fw)
|
|
@@ -208,12 +312,15 @@ static int rpi_firmware_probe(struct pla
|
|
}
|
|
|
|
init_completion(&fw->c);
|
|
+ INIT_DELAYED_WORK(&fw->get_throttled_poll_work, get_throttled_poll);
|
|
|
|
platform_set_drvdata(pdev, fw);
|
|
g_pdev = pdev;
|
|
|
|
rpi_firmware_print_firmware_revision(fw);
|
|
|
|
+ schedule_delayed_work(&fw->get_throttled_poll_work, 0);
|
|
+
|
|
return 0;
|
|
}
|
|
|
|
@@ -221,6 +328,7 @@ static int rpi_firmware_remove(struct pl
|
|
{
|
|
struct rpi_firmware *fw = platform_get_drvdata(pdev);
|
|
|
|
+ cancel_delayed_work_sync(&fw->get_throttled_poll_work);
|
|
mbox_free_channel(fw->chan);
|
|
g_pdev = NULL;
|
|
|
|
--- a/include/soc/bcm2835/raspberrypi-firmware.h
|
|
+++ b/include/soc/bcm2835/raspberrypi-firmware.h
|
|
@@ -77,6 +77,7 @@ enum rpi_firmware_property_tag {
|
|
RPI_FIRMWARE_GET_EDID_BLOCK = 0x00030020,
|
|
RPI_FIRMWARE_GET_CUSTOMER_OTP = 0x00030021,
|
|
RPI_FIRMWARE_GET_DOMAIN_STATE = 0x00030030,
|
|
+ RPI_FIRMWARE_GET_THROTTLED = 0x00030046,
|
|
RPI_FIRMWARE_SET_CLOCK_STATE = 0x00038001,
|
|
RPI_FIRMWARE_SET_CLOCK_RATE = 0x00038002,
|
|
RPI_FIRMWARE_SET_VOLTAGE = 0x00038003,
|