diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.14/950-0234-firmware-raspberrypi-Add-a-get_throttled-sysfs-file.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.14/950-0234-firmware-raspberrypi-Add-a-get_throttled-sysfs-file.patch | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.14/950-0234-firmware-raspberrypi-Add-a-get_throttled-sysfs-file.patch b/target/linux/brcm2708/patches-4.14/950-0234-firmware-raspberrypi-Add-a-get_throttled-sysfs-file.patch new file mode 100644 index 0000000000..ad6ea4b999 --- /dev/null +++ b/target/linux/brcm2708/patches-4.14/950-0234-firmware-raspberrypi-Add-a-get_throttled-sysfs-file.patch @@ -0,0 +1,206 @@ +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, |