power: Add an axp20x-usb-power driver
authorHans de Goede <hdegoede@redhat.com>
Sat, 1 Aug 2015 08:39:38 +0000 (10:39 +0200)
committerSebastian Reichel <sre@kernel.org>
Tue, 22 Sep 2015 11:35:28 +0000 (13:35 +0200)
This adds a driver for the usb power_supply bits of the axp20x PMICs.

I initially started writing my own driver, before coming aware of
Bruno Prémont's excellent earlier RFC with a driver for this.

My driver was lacking CURRENT_MAX and VOLTAGE_MIN support Bruno's
drvier has, so I've copied the code for those from his driver.

Note that the AC-power-supply and battery charger bits will need separate
drivers. Each one needs its own devictree child-node so that other
devicetree nodes can reference the right power-supply, and thus each one
will get its own mfd-cell / platform_device and platform-driver.

Cc: Bruno Prémont <bonbons@linux-vserver.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
drivers/power/Kconfig
drivers/power/Makefile
drivers/power/axp20x_usb_power.c [new file with mode: 0644]
include/linux/mfd/axp20x.h

index f8758d6febf818a7101d6019a55e389af315cea5..914167e14d2eb033ff69d191d60a228c1b0aaa95 100644 (file)
@@ -472,6 +472,13 @@ config CHARGER_RT9455
        help
          Say Y to enable support for Richtek RT9455 battery charger.
 
+config AXP20X_POWER
+       tristate "AXP20x power supply driver"
+       depends on MFD_AXP20X
+       help
+         This driver provides support for the power supply features of
+         AXP20x PMIC.
+
 source "drivers/power/reset/Kconfig"
 
 endif # POWER_SUPPLY
index 5752ce818f5157657ea93b5cc3873b38aaf5c61b..fb4413e5dd37037ebbd85d72a76e8e0fb38a5ab7 100644 (file)
@@ -9,6 +9,7 @@ obj-$(CONFIG_GENERIC_ADC_BATTERY)       += generic-adc-battery.o
 
 obj-$(CONFIG_PDA_POWER)                += pda_power.o
 obj-$(CONFIG_APM_POWER)                += apm_power.o
+obj-$(CONFIG_AXP20X_POWER)     += axp20x_usb_power.o
 obj-$(CONFIG_MAX8925_POWER)    += max8925_power.o
 obj-$(CONFIG_WM831X_BACKUP)    += wm831x_backup.o
 obj-$(CONFIG_WM831X_POWER)     += wm831x_power.o
diff --git a/drivers/power/axp20x_usb_power.c b/drivers/power/axp20x_usb_power.c
new file mode 100644 (file)
index 0000000..421a90b
--- /dev/null
@@ -0,0 +1,248 @@
+/*
+ * AXP20x PMIC USB power supply status driver
+ *
+ * Copyright (C) 2015 Hans de Goede <hdegoede@redhat.com>
+ * Copyright (C) 2014 Bruno Prémont <bonbons@linux-vserver.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under  the terms of the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mfd/axp20x.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define DRVNAME "axp20x-usb-power-supply"
+
+#define AXP20X_PWR_STATUS_VBUS_PRESENT BIT(5)
+#define AXP20X_PWR_STATUS_VBUS_USED    BIT(4)
+
+#define AXP20X_USB_STATUS_VBUS_VALID   BIT(2)
+
+#define AXP20X_VBUS_VHOLD_uV(b)                (4000000 + (((b) >> 3) & 7) * 100000)
+#define AXP20X_VBUS_CLIMIT_MASK                3
+#define AXP20X_VBUC_CLIMIT_900mA       0
+#define AXP20X_VBUC_CLIMIT_500mA       1
+#define AXP20X_VBUC_CLIMIT_100mA       2
+#define AXP20X_VBUC_CLIMIT_NONE                3
+
+#define AXP20X_ADC_EN1_VBUS_CURR       BIT(2)
+#define AXP20X_ADC_EN1_VBUS_VOLT       BIT(3)
+
+#define AXP20X_VBUS_MON_VBUS_VALID     BIT(3)
+
+struct axp20x_usb_power {
+       struct regmap *regmap;
+       struct power_supply *supply;
+};
+
+static irqreturn_t axp20x_usb_power_irq(int irq, void *devid)
+{
+       struct axp20x_usb_power *power = devid;
+
+       power_supply_changed(power->supply);
+
+       return IRQ_HANDLED;
+}
+
+static int axp20x_usb_power_get_property(struct power_supply *psy,
+       enum power_supply_property psp, union power_supply_propval *val)
+{
+       struct axp20x_usb_power *power = power_supply_get_drvdata(psy);
+       unsigned int input, v;
+       int ret;
+
+       switch (psp) {
+       case POWER_SUPPLY_PROP_VOLTAGE_MIN:
+               ret = regmap_read(power->regmap, AXP20X_VBUS_IPSOUT_MGMT, &v);
+               if (ret)
+                       return ret;
+
+               val->intval = AXP20X_VBUS_VHOLD_uV(v);
+               return 0;
+       case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+               ret = axp20x_read_variable_width(power->regmap,
+                                                AXP20X_VBUS_V_ADC_H, 12);
+               if (ret < 0)
+                       return ret;
+
+               val->intval = ret * 1700; /* 1 step = 1.7 mV */
+               return 0;
+       case POWER_SUPPLY_PROP_CURRENT_MAX:
+               ret = regmap_read(power->regmap, AXP20X_VBUS_IPSOUT_MGMT, &v);
+               if (ret)
+                       return ret;
+
+               switch (v & AXP20X_VBUS_CLIMIT_MASK) {
+               case AXP20X_VBUC_CLIMIT_100mA:
+                       val->intval = 100000;
+                       break;
+               case AXP20X_VBUC_CLIMIT_500mA:
+                       val->intval = 500000;
+                       break;
+               case AXP20X_VBUC_CLIMIT_900mA:
+                       val->intval = 900000;
+                       break;
+               case AXP20X_VBUC_CLIMIT_NONE:
+                       val->intval = -1;
+                       break;
+               }
+               return 0;
+       case POWER_SUPPLY_PROP_CURRENT_NOW:
+               ret = axp20x_read_variable_width(power->regmap,
+                                                AXP20X_VBUS_I_ADC_H, 12);
+               if (ret < 0)
+                       return ret;
+
+               val->intval = ret * 375; /* 1 step = 0.375 mA */
+               return 0;
+       default:
+               break;
+       }
+
+       /* All the properties below need the input-status reg value */
+       ret = regmap_read(power->regmap, AXP20X_PWR_INPUT_STATUS, &input);
+       if (ret)
+               return ret;
+
+       switch (psp) {
+       case POWER_SUPPLY_PROP_HEALTH:
+               if (!(input & AXP20X_PWR_STATUS_VBUS_PRESENT)) {
+                       val->intval = POWER_SUPPLY_HEALTH_UNKNOWN;
+                       break;
+               }
+
+               ret = regmap_read(power->regmap, AXP20X_USB_OTG_STATUS, &v);
+               if (ret)
+                       return ret;
+
+               if (!(v & AXP20X_USB_STATUS_VBUS_VALID)) {
+                       val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+                       break;
+               }
+
+               val->intval = POWER_SUPPLY_HEALTH_GOOD;
+               break;
+       case POWER_SUPPLY_PROP_PRESENT:
+               val->intval = !!(input & AXP20X_PWR_STATUS_VBUS_PRESENT);
+               break;
+       case POWER_SUPPLY_PROP_ONLINE:
+               val->intval = !!(input & AXP20X_PWR_STATUS_VBUS_USED);
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static enum power_supply_property axp20x_usb_power_properties[] = {
+       POWER_SUPPLY_PROP_HEALTH,
+       POWER_SUPPLY_PROP_PRESENT,
+       POWER_SUPPLY_PROP_ONLINE,
+       POWER_SUPPLY_PROP_VOLTAGE_MIN,
+       POWER_SUPPLY_PROP_VOLTAGE_NOW,
+       POWER_SUPPLY_PROP_CURRENT_MAX,
+       POWER_SUPPLY_PROP_CURRENT_NOW,
+};
+
+static const struct power_supply_desc axp20x_usb_power_desc = {
+       .name = "axp20x-usb",
+       .type = POWER_SUPPLY_TYPE_USB,
+       .properties = axp20x_usb_power_properties,
+       .num_properties = ARRAY_SIZE(axp20x_usb_power_properties),
+       .get_property = axp20x_usb_power_get_property,
+};
+
+static int axp20x_usb_power_probe(struct platform_device *pdev)
+{
+       struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
+       struct power_supply_config psy_cfg = {};
+       struct axp20x_usb_power *power;
+       static const char * const irq_names[] = { "VBUS_PLUGIN",
+               "VBUS_REMOVAL", "VBUS_VALID", "VBUS_NOT_VALID" };
+       int i, irq, ret;
+
+       if (!of_device_is_available(pdev->dev.of_node))
+               return -ENODEV;
+
+       if (!axp20x) {
+               dev_err(&pdev->dev, "Parent drvdata not set\n");
+               return -EINVAL;
+       }
+
+       power = devm_kzalloc(&pdev->dev, sizeof(*power), GFP_KERNEL);
+       if (!power)
+               return -ENOMEM;
+
+       power->regmap = axp20x->regmap;
+
+       /* Enable vbus valid checking */
+       ret = regmap_update_bits(power->regmap, AXP20X_VBUS_MON,
+                   AXP20X_VBUS_MON_VBUS_VALID, AXP20X_VBUS_MON_VBUS_VALID);
+       if (ret)
+               return ret;
+
+       /* Enable vbus voltage and current measurement */
+       ret = regmap_update_bits(power->regmap, AXP20X_ADC_EN1,
+                       AXP20X_ADC_EN1_VBUS_CURR | AXP20X_ADC_EN1_VBUS_VOLT,
+                       AXP20X_ADC_EN1_VBUS_CURR | AXP20X_ADC_EN1_VBUS_VOLT);
+       if (ret)
+               return ret;
+
+       psy_cfg.of_node = pdev->dev.of_node;
+       psy_cfg.drv_data = power;
+
+       power->supply = devm_power_supply_register(&pdev->dev,
+                                       &axp20x_usb_power_desc, &psy_cfg);
+       if (IS_ERR(power->supply))
+               return PTR_ERR(power->supply);
+
+       /* Request irqs after registering, as irqs may trigger immediately */
+       for (i = 0; i < ARRAY_SIZE(irq_names); i++) {
+               irq = platform_get_irq_byname(pdev, irq_names[i]);
+               if (irq < 0) {
+                       dev_warn(&pdev->dev, "No IRQ for %s: %d\n",
+                                irq_names[i], irq);
+                       continue;
+               }
+               irq = regmap_irq_get_virq(axp20x->regmap_irqc, irq);
+               ret = devm_request_any_context_irq(&pdev->dev, irq,
+                               axp20x_usb_power_irq, 0, DRVNAME, power);
+               if (ret < 0)
+                       dev_warn(&pdev->dev, "Error requesting %s IRQ: %d\n",
+                                irq_names[i], ret);
+       }
+
+       return 0;
+}
+
+static const struct of_device_id axp20x_usb_power_match[] = {
+       { .compatible = "x-powers,axp202-usb-power-supply" },
+       { }
+};
+MODULE_DEVICE_TABLE(of, axp20x_usb_power_match);
+
+static struct platform_driver axp20x_usb_power_driver = {
+       .probe = axp20x_usb_power_probe,
+       .driver = {
+               .name = DRVNAME,
+               .of_match_table = axp20x_usb_power_match,
+       },
+};
+
+module_platform_driver(axp20x_usb_power_driver);
+
+MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
+MODULE_DESCRIPTION("AXP20x PMIC USB power supply status driver");
+MODULE_LICENSE("GPL");
index cc8ad1e1a307bd1cf4eda99ed109dd9e53f178bf..b24c771cebd5c417dc2206553d4b2ecaa47773b5 100644 (file)
@@ -11,6 +11,8 @@
 #ifndef __LINUX_MFD_AXP20X_H
 #define __LINUX_MFD_AXP20X_H
 
+#include <linux/regmap.h>
+
 enum {
        AXP152_ID = 0,
        AXP202_ID,
@@ -438,4 +440,26 @@ struct axp288_extcon_pdata {
        struct gpio_desc *gpio_mux_cntl;
 };
 
+/* generic helper function for reading 9-16 bit wide regs */
+static inline int axp20x_read_variable_width(struct regmap *regmap,
+       unsigned int reg, unsigned int width)
+{
+       unsigned int reg_val, result;
+       int err;
+
+       err = regmap_read(regmap, reg, &reg_val);
+       if (err)
+               return err;
+
+       result = reg_val << (width - 8);
+
+       err = regmap_read(regmap, reg + 1, &reg_val);
+       if (err)
+               return err;
+
+       result |= reg_val;
+
+       return result;
+}
+
 #endif /* __LINUX_MFD_AXP20X_H */