doc/driver-model/UDM-power.txt

   1 The U-Boot Driver Model Project
   2 ===============================
   3 POWER analysis
   4 ==============
   5 Viktor Krivak <viktor.krivak@gmail.com>
   6 2012-03-09
   7
   8 I) Overview
   9 -----------
  10
  11   1) Actual state
  12   ---------------
  13
  14   At this moment power doesn't contain API. There are many methods for
  15   initialization of some board specific functions but only few does what is
  16   expected. Basically only one file contains something meaningful for this
  17   driver.
  18
  19   2) Current implementation
  20   -------------------------
  21
  22   In file twl6030.c are methods twl6030_stop_usb_charging() and
  23   twl6030_start_usb_charging() for start and stop charging from USB. There are
  24   also methods to get information about battery state and initialization of
  25   battery charging. Only these methods are used in converted API.
  26
  27
  28 II) Approach
  29 ------------
  30
  31   1) New API
  32   ----------
  33
  34   New API implements only functions specific for managing power. All board
  35   specific init methods are moved to other files. Name of methods are
  36   self-explanatory.
  37
  38   struct ops {
  39     void (*start_usb_charging)(struct instance *i);
  40     void (*stop_usb_charging)(struct instance *i);
  41     int  (*get_battery_current)(struct instance *i);
  42     int  (*get_battery_voltage)(struct instance *i);
  43     void (*init_battery_charging)(struct instance *i);
  44   }
  45
  46   2) Conversions of other methods
  47   -------------------------------
  48
  49   Methods that can't be converted to new API are moved to board file or to
  50   special file for board hacks.
  51
  52 III) Analysis of in-tree drivers
  53 --------------------------------
  54
  55   1) ftpmu010.c
  56   -------------
  57   All methods of this file are moved to another location.
  58     void ftpmu010_32768osc_enable(void): Move to boards hacks
  59     void ftpmu010_mfpsr_select_dev(unsigned int dev): Move to board file
  60                                                       arch/nds32/lib/board.c
  61     void ftpmu010_mfpsr_diselect_dev(unsigned int dev): Dead code
  62     void ftpmu010_dlldis_disable(void): Dead code
  63     void ftpmu010_sdram_clk_disable(unsigned int cr0): Move to board file
  64                                                        arch/nds32/lib/board.c
  65     void ftpmu010_sdramhtc_set(unsigned int val): Move to board file
  66                                                   arch/nds32/lib/board.c
  67
  68   2) twl4030.c
  69   ------------
  70   All methods of this file are moved to another location.
  71     void twl4030_power_reset_init(void): Move to board hacks
  72     void twl4030_pmrecv_vsel_cfg(u8 vsel_reg, u8 vsel_val, u8 dev_grp,
  73                                  u8 dev_grp_sel): Move to board hacks
  74     void twl4030_power_init(void): Move to board hacks
  75     void twl4030_power_mmc_init(void): Move to board hacks
  76
  77   3) twl6030.c
  78   ------------
  79   Some methods are converted to new API and rest are moved to another location.
  80     void twl6030_stop_usb_charging(void): Convert to new API
  81     void twl6030_start_usb_charging(void): Convert to new API
  82     int twl6030_get_battery_current(void): Convert to new API
  83     int twl6030_get_battery_voltage(void): Convert to new API
  84     void twl6030_init_battery_charging(void): Convert to new API
  85     void twl6030_power_mmc_init(): Move to board file
  86                                    drivers/mmc/omap_hsmmc.c
  87     void twl6030_usb_device_settings(): Move to board file
  88                                         drivers/usb/musb/omap3.c