On Tue, Dec 31, 2013 at 11:46:05PM +0100, Julian Andres Klode wrote:
> On Tue, Dec 31, 2013 at 10:12:31AM -0200, Henrique de Moraes Holschuh wrote:
> > On Tue, 31 Dec 2013, Julian Andres Klode wrote:
> > > We might be able to work around this by simple setting stop = start
> > > if a new write causes the stop threshold to be below the start
> > > threshold. But this also seems ugly.
> >
> > It is the safest way, but the correct pseudo-code would be, assuiming
> > unsigned:
> >
> > when someone changes start:
> >
> > if (start > 99)
> > start = 99;
>
> I think we should just return -EINVAL in such cases. Allowing users to
> write larger percentages is a bit pointless (we don't allow them to write
> negative ones either). And other promiment code (the backlight drivers)
> seem to reject out-of-range values.
>
> > set_thresholds(start, stop);
>
> I think there should not be some common set_thresholds, because we also
> need to write things in different orders for start / stop then:
>
> DECREASE STOP => Write new start if needed, then write stop
> INCREASE START => Write new stop if needed, then write start
>
> Otherwise we might have a very very very short time in which start
> is greater than stop.
>
> I'll incorporate this in real code and test it tomorrow.
>
OK, tommorow is now, 4 months later. I was to busy with
lectures. An updated patch is below that passes my small
test suite.
The next step is to integrate this properly with power supply
and/or acpi battery. One way would be to add additional power
supply properties and then add get/set_property() pointers to
the acpi battery which it can fall back to if it does not support
a requested property (and we would locate the ACPI battery and
set those pointers to new thinkpad_acpi functions).
Full changelog:
* Changed stop interval to 1..100
* Fixed name of attributes (tresh => thresh)
* Made sure to keep start < stop
-- >8 --
Subject: [PATCH 1/4] thinkpad_acpi: Add support for controlling charge
thresholds
Add support for battery charge thresholds in new Sandy Bridge and Ivy Bridge
ThinkPads. Based on the unofficial documentation in tpacpi-bat.
Signed-off-by: Julian Andres Klode <j...@jak-linux.org>
---
Documentation/laptops/thinkpad-acpi.txt | 15 ++
drivers/platform/x86/thinkpad_acpi.c | 235 ++++++++++++++++++++++++++++++++
2 files changed, 250 insertions(+)
diff --git a/Documentation/laptops/thinkpad-acpi.txt
b/Documentation/laptops/thinkpad-acpi.txt
index 86c5236..9b8a637 100644
--- a/Documentation/laptops/thinkpad-acpi.txt
+++ b/Documentation/laptops/thinkpad-acpi.txt
@@ -46,6 +46,7 @@ detailed description):
- Fan control and monitoring: fan speed, fan enable/disable
- WAN enable and disable
- UWB enable and disable
+ - Charging control
A compatibility table by model and feature is maintained on the web
site, http://ibm-acpi.sf.net/. I appreciate any success or failure
@@ -1352,6 +1353,20 @@ Sysfs notes:
rfkill controller switch "tpacpi_uwb_sw": refer to
Documentation/rfkill.txt for details.
+Charging control
+----------------
+sysfs attribute groups: BAT0, BAT1, and so on, depending on how many batteries
+are supported by the embedded controller.
+
+This feature controls the battery charging process.
+
+battery sysfs attribute: start_charge_thresh
+
+ A percentage value from 0-99%, controlling when charging should start
+
+battery sysfs attribute: stop_charge_thresh
+
+ A percentage value from 1-100%, controlling when charging should stop
Multiple Commands, Module Parameters
------------------------------------
diff --git a/drivers/platform/x86/thinkpad_acpi.c
b/drivers/platform/x86/thinkpad_acpi.c
index 03ca6c1..fa29d82 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -323,6 +323,7 @@ static struct {
u32 sensors_pdrv_attrs_registered:1;
u32 sensors_pdev_attrs_registered:1;
u32 hotkey_poll_active:1;
+ u32 battery:1;
} tp_features;
static struct {
@@ -8350,6 +8351,236 @@ static struct ibm_struct fan_driver_data = {
.resume = fan_resume,
};
+
+/*************************************************************************
+ * Battery subdriver
+ */
+
+/* Modify battery_init() if you modify them */
+#define BATTERY_MAX_COUNT 3
+#define BATTERY_MAX_ATTRS 2
+
+static struct battery {
+ char name[3 + 1 + 1];
+ struct attribute_set *set;
+ struct dev_ext_attribute attributes[BATTERY_MAX_ATTRS];
+} batteries[BATTERY_MAX_COUNT];
+
+static int battery_attribute_get_battery(struct device_attribute *attr)
+{
+ return (int) (unsigned long) container_of(attr,
+ struct dev_ext_attribute,
+ attr)->var;
+}
+
+static int battery_read_threshold(int bat, char *threshold)
+{
+ int result = 0;
+
+ if (!hkey_handle || !acpi_evalf(hkey_handle, &result, threshold,
+ "dd", bat) || result < 0)
+ return -EIO;
+
+ /* Translate 0 to 100 for stop threshold */
+ if (strcmp(threshold, "BCSG") == 0 && (result & 0xFF) == 0)
+ return 100;
+ /* Bits 0 - 7 contain the current threshold */
+ return result & 0xFF;
+}
+
+static int battery_write_stop_charge_thresh(int bat, int value,
+ bool adjust_start);
+
+static int battery_write_start_charge_thresh(int bat, int value,
+ bool adjust_stop)
+{
+ int res = 0;
+
+ if (value < 0 || value > 99)
+ return -EINVAL;
+
+ /* Adjust the stop value if stop < new start value */
+ if (adjust_stop) {
+ int stop = battery_read_threshold(bat, "BCSG");
+ if (stop < 0)
+ return stop;
+ if (stop <= value)
+ res = battery_write_stop_charge_thresh(bat, value + 1,
+ FALSE);
+ if (res)
+ return res;
+ }
+
+ if (!hkey_handle || !acpi_evalf(hkey_handle, &res, "BCCS", "dd",
+ value | (bat << 8)) || res < 0)
+ return -EIO;
+
+ return 0;
+}
+
+static int battery_write_stop_charge_thresh(int bat, int value,
+ bool adjust_start)
+{
+ int res = 0;
+
+ if (value < 1 || value > 100)
+ return -EINVAL;
+
+ /* Adjust the start value if start > new stop value */
+ if (adjust_start) {
+ int start = battery_read_threshold(bat, "BCTG");
+ if (start < 0)
+ return start;
+ if (value != 0)
+ res = battery_write_start_charge_thresh(bat, value - 1,
+ FALSE);
+ if (res)
+ return res;
+ }
+
+ /* 0 means default which seems to be 100%. */
+ if (value == 100)
+ value = 0;
+
+ if (!hkey_handle || !acpi_evalf(hkey_handle, &res, "BCSS", "dd",
+ value | (bat << 8)) || res < 0)
+ return -EIO;
+
+ return 0;
+}
+
+static ssize_t battery_start_charge_thresh_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int bat = battery_attribute_get_battery(attr);
+ int res = -EINVAL;
+ unsigned long value;
+
+ res = kstrtoul(buf, 0, &value);
+ if (res)
+ return res;
+ res = battery_write_start_charge_thresh(bat, value, TRUE);
+ return res ? res : count;
+}
+
+static ssize_t battery_stop_charge_thresh_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int bat = battery_attribute_get_battery(attr);
+ int res = -EINVAL;
+ unsigned long value;
+
+ res = kstrtoul(buf, 0, &value);
+ if (res)
+ return res;
+ res = battery_write_stop_charge_thresh(bat, value, TRUE);
+ return res ? res : count;
+}
+
+static ssize_t battery_start_charge_thresh_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ int bat = battery_attribute_get_battery(attr);
+ int value = battery_read_threshold(bat, "BCTG");
+
+ return value < 0 ? value : snprintf(buf, PAGE_SIZE, "%d\n", value);
+}
+
+static ssize_t battery_stop_charge_thresh_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ int bat = battery_attribute_get_battery(attr);
+ int value = battery_read_threshold(bat, "BCSG");
+
+ return value < 0 ? value : snprintf(buf, PAGE_SIZE, "%d\n", value);
+}
+
+static int __init battery_init(struct ibm_init_struct *iibm)
+{
+ int res;
+ int i;
+ int state;
+
+ vdbg_printk(TPACPI_DBG_INIT,
+ "initializing battery commands subdriver\n");
+
+ TPACPI_ACPIHANDLE_INIT(hkey);
+
+ /* Check whether getter for start threshold exists */
+ tp_features.battery = hkey_handle &&
+ acpi_evalf(hkey_handle, &state, "BCTG", "qdd", 1);
+
+ vdbg_printk(TPACPI_DBG_INIT, "battery commands are %s\n",
+ str_supported(tp_features.battery));
+
+ if (!tp_features.battery)
+ return 1;
+
+ for (i = 0; i < BATTERY_MAX_COUNT; i++) {
+ int j = 0;
+ if (!acpi_evalf(hkey_handle, &state, "BCTG", "qdd", i + 1))
+ continue;
+ /* If the sign bit was set, we could not get the start charge
+ * threshold of that battery. Let's assume that this battery
+ * (and all following ones) do not exist */
+ if (state < 0)
+ break;
+ /* Modify BATTERY_MAX_ATTRS if you add an attribute */
+ batteries[i].attributes[j++] = (struct dev_ext_attribute) {
+ .attr = __ATTR(start_charge_thresh,
+ S_IWUSR | S_IRUGO,
+ battery_start_charge_thresh_show,
+ battery_start_charge_thresh_store),
+ .var = (void *)(unsigned long) (i + 1)
+ };
+ batteries[i].attributes[j++] = (struct dev_ext_attribute) {
+ .attr = __ATTR(stop_charge_thresh,
+ S_IWUSR | S_IRUGO,
+ battery_stop_charge_thresh_show,
+ battery_stop_charge_thresh_store),
+ .var = (void *)(unsigned long) (i + 1)
+ };
+
+ strncpy(batteries[i].name, "BAT", 3);
+ batteries[i].name[3] = '0' + i;
+ batteries[i].name[4] = '\0';
+ batteries[i].set = create_attr_set(j, batteries[i].name);
+
+ for (j = j - 1; j >= 0; j--)
+ add_to_attr_set(batteries[i].set,
+ &batteries[i].attributes[j].attr.attr);
+
+ res = register_attr_set_with_sysfs(batteries[i].set,
+ &tpacpi_pdev->dev.kobj);
+
+ if (res)
+ return res;
+ }
+
+ return 0;
+}
+
+static void battery_exit(void)
+{
+ int i;
+
+ for (i = 0; i < BATTERY_MAX_COUNT; i++) {
+ if (batteries[i].set != NULL) {
+ delete_attr_set(batteries[i].set,
+ &tpacpi_pdev->dev.kobj);
+ }
+ }
+}
+
+static struct ibm_struct battery_driver_data = {
+ .name = "battery",
+ .exit = battery_exit,
+};
+
/****************************************************************************
****************************************************************************
*
@@ -8741,6 +8972,10 @@ static struct ibm_init_struct ibms_init[] __initdata = {
.data = &light_driver_data,
},
{
+ .init = battery_init,
+ .data = &battery_driver_data,
+ },
+ {
.init = cmos_init,
.data = &cmos_driver_data,
},
--
1.9.1
--
Julian Andres Klode - Debian Developer, Ubuntu Member
See http://wiki.debian.org/JulianAndresKlode and http://jak-linux.org/.
Please do not top-post if possible.
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