[PATCH v2 4/4] power: supply: add Ingenic JZ47xx battery driver.

Artur Rojek
2019-03-23T17:28:46Z

Add a driver for battery present on Ingenic JZ47xx SoCs.

Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
---

Changes:

v2: - rework the return logic in ingenic_battery_get_property,
- make index offsets point forward in ingenic_battery_set_scale,
- fix spacing around scale_raw[best_idx + 1]

drivers/power/supply/Kconfig | 11 ++
drivers/power/supply/Makefile | 1 +
drivers/power/supply/ingenic-battery.c | 180 +++++++++++++++++++++++++
3 files changed, 192 insertions(+)
create mode 100644 drivers/power/supply/ingenic-battery.c

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index e901b9879e7e..9bfb1637ec28 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -169,6 +169,17 @@ config BATTERY_COLLIE
Say Y to enable support for the battery on the Sharp Zaurus
SL-5500 (collie) models.

+config BATTERY_INGENIC
+ tristate "Ingenic JZ47xx SoCs battery driver"
+ depends on MIPS || COMPILE_TEST
+ depends on INGENIC_ADC
+ help
+ Choose this option if you want to monitor battery status on
+ Ingenic JZ47xx SoC based devices.
+
+ This driver can also be built as a module. If so, the module will be
+ called ingenic-battery.
+
config BATTERY_IPAQ_MICRO
tristate "iPAQ Atmel Micro ASIC battery driver"
depends on MFD_IPAQ_MICRO
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index b731c2a9b695..9e2c481d0187 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_BATTERY_PMU) += pmu_battery.o
obj-$(CONFIG_BATTERY_OLPC) += olpc_battery.o
obj-$(CONFIG_BATTERY_TOSA) += tosa_battery.o
obj-$(CONFIG_BATTERY_COLLIE) += collie_battery.o
+obj-$(CONFIG_BATTERY_INGENIC) += ingenic-battery.o
obj-$(CONFIG_BATTERY_IPAQ_MICRO) += ipaq_micro_battery.o
obj-$(CONFIG_BATTERY_WM97XX) += wm97xx_battery.o
obj-$(CONFIG_BATTERY_SBS) += sbs-battery.o
diff --git a/drivers/power/supply/ingenic-battery.c b/drivers/power/supply/ingenic-battery.c
new file mode 100644
index 000000000000..822aee1c7b64
--- /dev/null
+++ b/drivers/power/supply/ingenic-battery.c
@@ -0,0 +1,180 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Battery driver for the Ingenic JZ47xx SoCs
+ * Copyright (c) 2019 Artur Rojek <contact@artur-rojek.eu>
+ *
+ * based on drivers/power/supply/jz4740-battery.c
+ */
+
+#include <linux/iio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/property.h>
+
+struct ingenic_battery {
+ struct device *dev;
+ struct iio_channel *channel;
+ struct power_supply_desc desc;
+ struct power_supply *battery;
+ struct power_supply_battery_info info;
+};
+
+static int ingenic_battery_get_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct ingenic_battery *bat = power_supply_get_drvdata(psy);
+ struct power_supply_battery_info *info = &bat->info;
+ int ret;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_HEALTH:
+ ret = iio_read_channel_processed(bat->channel, &val->intval);
+ val->intval *= 1000;
+ if (val->intval < info->voltage_min_design_uv)
+ val->intval = POWER_SUPPLY_HEALTH_DEAD;
+ else if (val->intval > info->voltage_max_design_uv)
+ val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
+ else
+ val->intval = POWER_SUPPLY_HEALTH_GOOD;
+ return ret;
+ case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+ ret = iio_read_channel_processed(bat->channel, &val->intval);
+ val->intval *= 1000;
+ return ret;
+ case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
+ val->intval = info->voltage_min_design_uv;
+ return 0;
+ case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+ val->intval = info->voltage_max_design_uv;
+ return 0;
+ default:
+ return -EINVAL;
+ };
+}
+
+/* Set the most appropriate IIO channel voltage reference scale
+ * based on the battery's max voltage.
+ */
+static int ingenic_battery_set_scale(struct ingenic_battery *bat)
+{
+ const int *scale_raw;
+ int scale_len, scale_type, best_idx = -1, best_mV, max_raw, i, ret;
+ u64 max_mV;
+
+ ret = iio_read_max_channel_raw(bat->channel, &max_raw);
+ if (ret) {
+ dev_err(bat->dev, "Unable to read max raw channel value\n");
+ return ret;
+ }
+
+ ret = iio_read_avail_channel_attribute(bat->channel, &scale_raw,
+ &scale_type, &scale_len,
+ IIO_CHAN_INFO_SCALE);
+ if (ret < 0) {
+ dev_err(bat->dev, "Unable to read channel avail scale\n");
+ return ret;
+ }
+ if (ret != IIO_AVAIL_LIST || scale_type != IIO_VAL_FRACTIONAL_LOG2)
+ return -EINVAL;
+
+ max_mV = bat->info.voltage_max_design_uv / 1000;
+
+ for (i = 0; i < scale_len; i += 2) {
+ u64 scale_mV = (max_raw * scale_raw[i]) >> scale_raw[i + 1];
+
+ if (scale_mV < max_mV)
+ continue;
+
+ if (best_idx >= 0 && scale_mV > best_mV)
+ continue;
+
+ best_mV = scale_mV;
+ best_idx = i;
+ }
+
+ if (best_idx < 0) {
+ dev_err(bat->dev, "Unable to find matching voltage scale\n");
+ return -EINVAL;
+ }
+
+ return iio_write_channel_attribute(bat->channel,
+ scale_raw[best_idx],
+ scale_raw[best_idx + 1],
+ IIO_CHAN_INFO_SCALE);
+}
+
+static enum power_supply_property ingenic_battery_properties[] = {
+ POWER_SUPPLY_PROP_HEALTH,
+ POWER_SUPPLY_PROP_VOLTAGE_NOW,
+ POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
+ POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
+};
+
+static int ingenic_battery_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct ingenic_battery *bat;
+ struct power_supply_config psy_cfg = {};
+ struct power_supply_desc *desc;
+ int ret;
+
+ bat = devm_kzalloc(dev, sizeof(*bat), GFP_KERNEL);
+ if (!bat)
+ return -ENOMEM;
+
+ bat->dev = dev;
+ bat->channel = devm_iio_channel_get(dev, "battery");
+ if (IS_ERR(bat->channel))
+ return PTR_ERR(bat->channel);
+
+ desc = &bat->desc;
+ desc->name = "jz-battery";
+ desc->type = POWER_SUPPLY_TYPE_BATTERY;
+ desc->properties = ingenic_battery_properties;
+ desc->num_properties = ARRAY_SIZE(ingenic_battery_properties);
+ desc->get_property = ingenic_battery_get_property;
+ psy_cfg.drv_data = bat;
+ psy_cfg.of_node = dev->of_node;
+
+ bat->battery = devm_power_supply_register(dev, desc, &psy_cfg);
+ if (IS_ERR(bat->battery)) {
+ dev_err(dev, "Unable to register battery\n");
+ return PTR_ERR(bat->battery);
+ }
+
+ ret = power_supply_get_battery_info(bat->battery, &bat->info);
+ if (ret) {
+ dev_err(dev, "Unable to get battery info: %d\n", ret);
+ return ret;
+ }
+ if (bat->info.voltage_min_design_uv < 0) {
+ dev_err(dev, "Unable to get voltage min design\n");
+ return bat->info.voltage_min_design_uv;
+ }
+ if (bat->info.voltage_max_design_uv < 0) {
+ dev_err(dev, "Unable to get voltage max design\n");
+ return bat->info.voltage_max_design_uv;
+ }
+
+ return ingenic_battery_set_scale(bat);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id ingenic_battery_of_match[] = {
+ { .compatible = "ingenic,jz4740-battery", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, ingenic_battery_of_match);
+#endif
+
+static struct platform_driver ingenic_battery_driver = {
+ .driver = {
+ .name = "ingenic-battery",
+ .of_match_table = of_match_ptr(ingenic_battery_of_match),
+ },
+ .probe = ingenic_battery_probe,
+};
+module_platform_driver(ingenic_battery_driver);
--
2.21.0