power: pmic/regulator: Add basic support for TPS65910

Texas Instrument's TPS65910 PMIC contains 3 buck DC-DC converts, one boost DC-DC converter and 8 LDOs. This patch implements driver model support for the TPS65910 PMIC and its regulators making the get/set API for regulator value/enable available.
This patch depends on the patch "am33xx: Add a function to query MPU voltage in uV" to build correctly. For boards relying on the DT include file tps65910.dtsi the v3 patch "power: extend prefix match to regulator-name property" and an appropriate regulator naming is also required.

Signed-off-by Felix Brack <[email protected]>

---

Changes in v2:
- move information about regulator supply power from the PMIC to the regulator driver which greatly simplifies and streamlines the code of both drivers (thanks Simon!)
- use dev_get_uclass_platdata() to get the regulator constraints instead of reinventing the wheel and reading them from the DT
- make pmic_tps65910_write() and pmic_tps65910_read() return the results of the i2c operation instead of obscuring it
- generally review and eventually fix return values
- modify regulator description in Kconfig
- get_ctrl_reg_from_unit_addr() uses a lookup array instead of a switch statement
- rename some local functions to prevent confusion with generic functions
- reformatting code for better readability

 drivers/power/pmic/Kconfig                   |   8 +
 drivers/power/pmic/Makefile                  |   1 +
 drivers/power/pmic/pmic_tps65910_dm.c        |  98 ++++++
 drivers/power/regulator/Kconfig              |   8 +
 drivers/power/regulator/Makefile             |   1 +
 drivers/power/regulator/tps65910_regulator.c | 456 +++++++++++++++++++++++++++
 include/power/tps65910_pmic.h                | 129 ++++++++
 7 files changed, 701 insertions(+)
 create mode 100644 drivers/power/pmic/pmic_tps65910_dm.c
 create mode 100644 drivers/power/regulator/tps65910_regulator.c
 create mode 100644 include/power/tps65910_pmic.h

drivers/power/regulator/Makefile +1 -0

index 18fb870..3eef297 100644
@@ -20,3 +20,4 @@ obj-$(CONFIG_REGULATOR_TPS65090) += tps65090_regulator.o
 obj-$(CONFIG_$(SPL_)DM_REGULATOR_PALMAS) += palmas_regulator.o
 obj-$(CONFIG_$(SPL_)DM_REGULATOR_LP873X) += lp873x_regulator.o
 obj-$(CONFIG_$(SPL_)DM_REGULATOR_LP87565) += lp87565_regulator.o
+obj-$(CONFIG_DM_REGULATOR_TPS65910) += tps65910_regulator.o

drivers/power/regulator/tps65910_regulator.c new file +12 -0

new file mode 100644
index 0000000..8e29b53
@@ -0,0 +1,456 @@
+/*
+ * Copyright (C) EETS GmbH, 2017, Felix Brack <[email protected]>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <power/pmic.h>
+#include <power/regulator.h>
+#include <power/tps65910_pmic.h>
+

drivers/power/regulator/tps65910_regulator.c new file +7 -0

+       int vout = 0;
+       struct tps65910_regulator_pdata *pdata = dev->platdata;
+       int vin = pdata->supply;
+
+       val = pmic_reg_read(dev->parent, rgp->reg);
+       if (val < 0)
+               return val;

drivers/power/regulator/tps65910_regulator.c new file +27 -0

+       int vin = pdata->supply;
+
+       switch (dev->driver_data) {
+       case TPS65910_UNIT_VRTC:
+               /* VRTC is fixed and can't be turned off */
+               return (vin >= 2500000) ? 1830000 : 0;
+       case TPS65910_UNIT_VDIG1:
+               return tps65910_regulator_get_value(dev, &ldo_props_vdig1);
+       case TPS65910_UNIT_VDIG2:
+               return tps65910_regulator_get_value(dev, &ldo_props_vdig2);
+       case TPS65910_UNIT_VPLL:
+               return tps65910_regulator_get_value(dev, &ldo_props_vpll);
+       case TPS65910_UNIT_VDAC:
+               return tps65910_regulator_get_value(dev, &ldo_props_vdac);
+       case TPS65910_UNIT_VAUX1:
+               return tps65910_regulator_get_value(dev, &ldo_props_vaux1);
+       case TPS65910_UNIT_VAUX2:
+               return tps65910_regulator_get_value(dev, &ldo_props_vaux2);
+       case TPS65910_UNIT_VAUX33:
+               return tps65910_regulator_get_value(dev, &ldo_props_vaux33);
+       case TPS65910_UNIT_VMMC:
+               return tps65910_regulator_get_value(dev, &ldo_props_vmmc);
+       }
+
+       return 0;
+}
+

drivers/power/regulator/tps65910_regulator.c new file +7 -0

+       if (ret)
+               return ret;
+
+       /* bits 1:0 of regulator control register define state */
+       return ((val & TPS65910_SUPPLY_STATE_MASK) == 1);
+}
+

drivers/power/regulator/tps65910_regulator.c new file +4 -0

+       case TPS65910_UNIT_VIO:
+               vout = tps65910_regulator_get_value(dev, &smps_props_vio);
+               break;
+       case TPS65910_UNIT_VDD1: