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authorNick Crews <ncrews@chromium.org>2019-05-08 14:38:25 -0600
committerSebastian Reichel <sre@kernel.org>2019-07-05 00:54:36 +0200
commit3f57fe28f84d636ca6238f33afe8b88d27c34d1b (patch)
tree100b61b903f393fbc63ce161d4238c849f38a8b8 /drivers/power
parent1e10694d535fd1158c4ff16a841c23400af4d01e (diff)
power_supply: wilco_ec: Add charging config driver
Add a driver to control the charging algorithm used on Wilco devices. See Documentation/ABI/testing/sysfs-class-power-wilco for the userspace interface and other info. Signed-off-by: Nick Crews <ncrews@chromium.org> Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Diffstat (limited to 'drivers/power')
-rw-r--r--drivers/power/supply/Kconfig9
-rw-r--r--drivers/power/supply/Makefile1
-rw-r--r--drivers/power/supply/wilco-charger.c187
3 files changed, 197 insertions, 0 deletions
diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 1f2252cb95fd..4c01598f5ccb 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -702,4 +702,13 @@ config CHARGER_UCS1002
Say Y to enable support for Microchip UCS1002 Programmable
USB Port Power Controller with Charger Emulation.
+config CHARGER_WILCO
+ tristate "Wilco EC based charger for ChromeOS"
+ depends on WILCO_EC
+ help
+ Say Y here to enable control of the charging routines performed
+ by the Embedded Controller on the Chromebook named Wilco. Further
+ information can be found in
+ Documentation/ABI/testing/sysfs-class-power-wilco
+
endif # POWER_SUPPLY
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index c47e88ba16b9..d2263e1e2b6f 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -91,3 +91,4 @@ obj-$(CONFIG_CHARGER_CROS_USBPD) += cros_usbpd-charger.o
obj-$(CONFIG_CHARGER_SC2731) += sc2731_charger.o
obj-$(CONFIG_FUEL_GAUGE_SC27XX) += sc27xx_fuel_gauge.o
obj-$(CONFIG_CHARGER_UCS1002) += ucs1002_power.o
+obj-$(CONFIG_CHARGER_WILCO) += wilco-charger.o
diff --git a/drivers/power/supply/wilco-charger.c b/drivers/power/supply/wilco-charger.c
new file mode 100644
index 000000000000..b3c6d7cdd731
--- /dev/null
+++ b/drivers/power/supply/wilco-charger.c
@@ -0,0 +1,187 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Charging control driver for the Wilco EC
+ *
+ * Copyright 2019 Google LLC
+ *
+ * See Documentation/ABI/testing/sysfs-class-power and
+ * Documentation/ABI/testing/sysfs-class-power-wilco for userspace interface
+ * and other info.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/wilco-ec.h>
+#include <linux/power_supply.h>
+
+#define DRV_NAME "wilco-charger"
+
+/* Property IDs and related EC constants */
+#define PID_CHARGE_MODE 0x0710
+#define PID_CHARGE_LOWER_LIMIT 0x0711
+#define PID_CHARGE_UPPER_LIMIT 0x0712
+
+enum charge_mode {
+ CHARGE_MODE_STD = 1, /* Used for Standard */
+ CHARGE_MODE_EXP = 2, /* Express Charge, used for Fast */
+ CHARGE_MODE_AC = 3, /* Mostly AC use, used for Trickle */
+ CHARGE_MODE_AUTO = 4, /* Used for Adaptive */
+ CHARGE_MODE_CUSTOM = 5, /* Used for Custom */
+};
+
+#define CHARGE_LOWER_LIMIT_MIN 50
+#define CHARGE_LOWER_LIMIT_MAX 95
+#define CHARGE_UPPER_LIMIT_MIN 55
+#define CHARGE_UPPER_LIMIT_MAX 100
+
+/* Convert from POWER_SUPPLY_PROP_CHARGE_TYPE value to the EC's charge mode */
+static int psp_val_to_charge_mode(int psp_val)
+{
+ switch (psp_val) {
+ case POWER_SUPPLY_CHARGE_TYPE_TRICKLE:
+ return CHARGE_MODE_AC;
+ case POWER_SUPPLY_CHARGE_TYPE_FAST:
+ return CHARGE_MODE_EXP;
+ case POWER_SUPPLY_CHARGE_TYPE_STANDARD:
+ return CHARGE_MODE_STD;
+ case POWER_SUPPLY_CHARGE_TYPE_ADAPTIVE:
+ return CHARGE_MODE_AUTO;
+ case POWER_SUPPLY_CHARGE_TYPE_CUSTOM:
+ return CHARGE_MODE_CUSTOM;
+ default:
+ return -EINVAL;
+ }
+}
+
+/* Convert from EC's charge mode to POWER_SUPPLY_PROP_CHARGE_TYPE value */
+static int charge_mode_to_psp_val(enum charge_mode mode)
+{
+ switch (mode) {
+ case CHARGE_MODE_AC:
+ return POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
+ case CHARGE_MODE_EXP:
+ return POWER_SUPPLY_CHARGE_TYPE_FAST;
+ case CHARGE_MODE_STD:
+ return POWER_SUPPLY_CHARGE_TYPE_STANDARD;
+ case CHARGE_MODE_AUTO:
+ return POWER_SUPPLY_CHARGE_TYPE_ADAPTIVE;
+ case CHARGE_MODE_CUSTOM:
+ return POWER_SUPPLY_CHARGE_TYPE_CUSTOM;
+ default:
+ return -EINVAL;
+ }
+}
+
+static enum power_supply_property wilco_charge_props[] = {
+ POWER_SUPPLY_PROP_CHARGE_TYPE,
+ POWER_SUPPLY_PROP_CHARGE_CONTROL_START_THRESHOLD,
+ POWER_SUPPLY_PROP_CHARGE_CONTROL_END_THRESHOLD,
+};
+
+static int wilco_charge_get_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct wilco_ec_device *ec = power_supply_get_drvdata(psy);
+ u32 property_id;
+ int ret;
+ u8 raw;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_CHARGE_TYPE:
+ property_id = PID_CHARGE_MODE;
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_CONTROL_START_THRESHOLD:
+ property_id = PID_CHARGE_LOWER_LIMIT;
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_CONTROL_END_THRESHOLD:
+ property_id = PID_CHARGE_UPPER_LIMIT;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ret = wilco_ec_get_byte_property(ec, property_id, &raw);
+ if (ret < 0)
+ return ret;
+ if (property_id == PID_CHARGE_MODE) {
+ ret = charge_mode_to_psp_val(raw);
+ if (ret < 0)
+ return -EBADMSG;
+ raw = ret;
+ }
+ val->intval = raw;
+
+ return 0;
+}
+
+static int wilco_charge_set_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ const union power_supply_propval *val)
+{
+ struct wilco_ec_device *ec = power_supply_get_drvdata(psy);
+ int mode;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_CHARGE_TYPE:
+ mode = psp_val_to_charge_mode(val->intval);
+ if (mode < 0)
+ return -EINVAL;
+ return wilco_ec_set_byte_property(ec, PID_CHARGE_MODE, mode);
+ case POWER_SUPPLY_PROP_CHARGE_CONTROL_START_THRESHOLD:
+ if (val->intval < CHARGE_LOWER_LIMIT_MIN ||
+ val->intval > CHARGE_LOWER_LIMIT_MAX)
+ return -EINVAL;
+ return wilco_ec_set_byte_property(ec, PID_CHARGE_LOWER_LIMIT,
+ val->intval);
+ case POWER_SUPPLY_PROP_CHARGE_CONTROL_END_THRESHOLD:
+ if (val->intval < CHARGE_UPPER_LIMIT_MIN ||
+ val->intval > CHARGE_UPPER_LIMIT_MAX)
+ return -EINVAL;
+ return wilco_ec_set_byte_property(ec, PID_CHARGE_UPPER_LIMIT,
+ val->intval);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int wilco_charge_property_is_writeable(struct power_supply *psy,
+ enum power_supply_property psp)
+{
+ return 1;
+}
+
+static const struct power_supply_desc wilco_ps_desc = {
+ .properties = wilco_charge_props,
+ .num_properties = ARRAY_SIZE(wilco_charge_props),
+ .get_property = wilco_charge_get_property,
+ .set_property = wilco_charge_set_property,
+ .property_is_writeable = wilco_charge_property_is_writeable,
+ .name = DRV_NAME,
+ .type = POWER_SUPPLY_TYPE_MAINS,
+};
+
+static int wilco_charge_probe(struct platform_device *pdev)
+{
+ struct wilco_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
+ struct power_supply_config psy_cfg = {};
+ struct power_supply *psy;
+
+ psy_cfg.drv_data = ec;
+ psy = devm_power_supply_register(&pdev->dev, &wilco_ps_desc, &psy_cfg);
+
+ return PTR_ERR_OR_ZERO(psy);
+}
+
+static struct platform_driver wilco_charge_driver = {
+ .probe = wilco_charge_probe,
+ .driver = {
+ .name = DRV_NAME,
+ }
+};
+module_platform_driver(wilco_charge_driver);
+
+MODULE_ALIAS("platform:" DRV_NAME);
+MODULE_AUTHOR("Nick Crews <ncrews@chromium.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Wilco EC charge control driver");