power: supply: add Ingenic JZ47xx battery driver.

Add a driver for battery present on Ingenic JZ47xx SoCs.

Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index e907521a71660e920b4a9c0993b0b4a5c8cbb633..4728a218656f62e17437e89734f7602f4149d767 100644 (file)
--- 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 a2b3ab157ca0bb8b37114e5fb194625cb36569ec..39fc3e91e619718106607e399c103028b06bf1fa 100644 (file)
--- 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 (file)
index 0000000..35816d4
--- /dev/null
+++ b/drivers/power/supply/ingenic-battery.c
@@ -0,0 +1,184 @@
+// 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);
+
+MODULE_DESCRIPTION("Battery driver for Ingenic JZ47xx SoCs");
+MODULE_AUTHOR("Artur Rojek <contact@artur-rojek.eu>");
+MODULE_LICENSE("GPL");