Merge tag 'for-v3.18' of git://git.infradead.org/battery-2.6

Pull power supply and reset updates from Sebastian Reichel:
 - Initial support for the following chips
   * max77836 (charger)
   * max14577 (charger)
   * bq27742 (battery gauge)
   * ltc2952 (poweroff)
   * stih416 (restart)
   * syscon-reboot (restart)
   * gpio-restart (restart)
 - cleanup of power supply core
 - misc fixes in power supply and reset drivers

* tag 'for-v3.18' of git://git.infradead.org/battery-2.6: (48 commits)
  power: ab8500_fg: Fix build warning
  Documentation: charger: max14577: Update the date of introducing ABI
  power: reset: corrections for simple syscon reboot driver
  Documentation: power: reset: Add documentation for generic SYSCON reboot driver
  power: reset: Add generic SYSCON register mapped reset
  bq27x00_battery: Fix flag reading for bq27742
  power: reset: use restart_notifier mechanism for msm-poweroff
  power: Add simple gpio-restart driver
  power: reset: st: Provide DT bindings for ST's Power Reset driver
  power: reset: Add restart functionality for STiH41x platforms
  power: charger-manager: Fix NULL pointer exception with missing cm-fuel-gauge
  power: max14577: Fix circular config SYSFS dependency
  power: gpio-charger: do not use gpio value directly
  power: max8925: Use of_get_child_by_name
  power: max8925: Fix NULL ptr dereference on memory allocation failure
  bq27x00_battery: Add support to bq27742
  Documentation: charger: max14577: Document exported sysfs entry
  devicetree: mfd: max14577: Add device tree bindings document
  power: max17040: Add ID for MAX77836 Fuel Gauge block
  charger: max14577: Configure battery-dependent settings from DTS and sysfs
  ...

Conflicts:
	drivers/power/reset/Kconfig
	drivers/power/reset/Makefile

1 files changed, 99 insertions, 1 deletions

diff --git a/drivers/mfd/max14577.c b/drivers/mfd/max14577.c
index 4a5e885383f8..b8af263be594 100644
--- a/drivers/mfd/max14577.c
+++ b/drivers/mfd/max14577.c
@@ -26,6 +26,87 @@
 #include <linux/mfd/max14577.h>
 #include <linux/mfd/max14577-private.h>
 
+/*
+ * Table of valid charger currents for different Maxim chipsets.
+ * It is placed here because it is used by both charger and regulator driver.
+ */
+const struct maxim_charger_current maxim_charger_currents[] = {
+        [MAXIM_DEVICE_TYPE_UNKNOWN] = { 0, 0, 0, 0 },
+        [MAXIM_DEVICE_TYPE_MAX14577] = {
+                .min            = MAX14577_CHARGER_CURRENT_LIMIT_MIN,
+                .high_start     = MAX14577_CHARGER_CURRENT_LIMIT_HIGH_START,
+                .high_step      = MAX14577_CHARGER_CURRENT_LIMIT_HIGH_STEP,
+                .max            = MAX14577_CHARGER_CURRENT_LIMIT_MAX,
+        },
+        [MAXIM_DEVICE_TYPE_MAX77836] = {
+                .min            = MAX77836_CHARGER_CURRENT_LIMIT_MIN,
+                .high_start     = MAX77836_CHARGER_CURRENT_LIMIT_HIGH_START,
+                .high_step      = MAX77836_CHARGER_CURRENT_LIMIT_HIGH_STEP,
+                .max            = MAX77836_CHARGER_CURRENT_LIMIT_MAX,
+        },
+};
+EXPORT_SYMBOL_GPL(maxim_charger_currents);
+
+/*
+ * maxim_charger_calc_reg_current - Calculate register value for current
+ * @limits:     constraints for charger, matching the MBCICHWRC register
+ * @min_ua:     minimal requested current, micro Amps
+ * @max_ua:     maximum requested current, micro Amps
+ * @dst:        destination to store calculated register value
+ *
+ * Calculates the value of MBCICHWRC (Fast Battery Charge Current) register
+ * for given current and stores it under pointed 'dst'. The stored value
+ * combines low bit (MBCICHWRCL) and high bits (MBCICHWRCH). It is also
+ * properly shifted.
+ *
+ * The calculated register value matches the current which:
+ *  - is always between <limits.min, limits.max>;
+ *  - is always less or equal to max_ua;
+ *  - is the highest possible value;
+ *  - may be lower than min_ua.
+ *
+ * On success returns 0. On error returns -EINVAL (requested min/max current
+ * is outside of given charger limits) and 'dst' is not set.
+ */
+int maxim_charger_calc_reg_current(const struct maxim_charger_current *limits,
+                unsigned int min_ua, unsigned int max_ua, u8 *dst)
+{
+        unsigned int current_bits = 0xf;
+
+        if (min_ua > max_ua)
+                return -EINVAL;
+
+        if (min_ua > limits->max || max_ua < limits->min)
+                return -EINVAL;
+
+        if (max_ua < limits->high_start) {
+                /*
+                 * Less than high_start, so set the minimal current
+                 * (turn Low Bit off, 0 as high bits).
+                 */
+                *dst = 0x0;
+                return 0;
+        }
+
+        /* max_ua is in range: <high_start, infinite>, cut it to limits.max */
+        max_ua = min(limits->max, max_ua);
+        max_ua -= limits->high_start;
+        /*
+         * There is no risk of overflow 'max_ua' here because:
+         *  - max_ua >= limits.high_start
+         *  - BUILD_BUG checks that 'limits' are: max >= high_start + high_step
+         */
+        current_bits = max_ua / limits->high_step;
+
+        /* Turn Low Bit on (use range <limits.high_start, limits.max>) ... */
+        *dst = 0x1 << CHGCTRL4_MBCICHWRCL_SHIFT;
+        /* and set proper High Bits */
+        *dst |= current_bits << CHGCTRL4_MBCICHWRCH_SHIFT;
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(maxim_charger_calc_reg_current);
+
 static const struct mfd_cell max14577_devs[] = {
         {
                 .name = "max14577-muic",
@@ -35,7 +116,10 @@ static const struct mfd_cell max14577_devs[] = {
                 .name = "max14577-regulator",
                 .of_compatible = "maxim,max14577-regulator",
         },
-        { .name = "max14577-charger", },
+        {
+                .name = "max14577-charger",
+                .of_compatible = "maxim,max14577-charger",
+        },
 };
 
 static const struct mfd_cell max77836_devs[] = {
@@ -463,6 +547,20 @@ static int __init max14577_i2c_init(void)
         BUILD_BUG_ON(ARRAY_SIZE(max14577_i2c_id) != MAXIM_DEVICE_TYPE_NUM);
         BUILD_BUG_ON(ARRAY_SIZE(max14577_dt_match) != MAXIM_DEVICE_TYPE_NUM);
 
+        /* Valid charger current values must be provided for each chipset */
+        BUILD_BUG_ON(ARRAY_SIZE(maxim_charger_currents) != MAXIM_DEVICE_TYPE_NUM);
+
+        /* Check for valid values for charger */
+        BUILD_BUG_ON(MAX14577_CHARGER_CURRENT_LIMIT_HIGH_START +
+                        MAX14577_CHARGER_CURRENT_LIMIT_HIGH_STEP * 0xf !=
+                        MAX14577_CHARGER_CURRENT_LIMIT_MAX);
+        BUILD_BUG_ON(MAX14577_CHARGER_CURRENT_LIMIT_HIGH_STEP == 0);
+
+        BUILD_BUG_ON(MAX77836_CHARGER_CURRENT_LIMIT_HIGH_START +
+                        MAX77836_CHARGER_CURRENT_LIMIT_HIGH_STEP * 0xf !=
+                        MAX77836_CHARGER_CURRENT_LIMIT_MAX);
+        BUILD_BUG_ON(MAX77836_CHARGER_CURRENT_LIMIT_HIGH_STEP == 0);
+
         return i2c_add_driver(&max14577_i2c_driver);
 }
 subsys_initcall(max14577_i2c_init);