drivers/mfd/ab8500-sysctrl.c

   1 /*
   2  * Copyright (C) ST-Ericsson SA 2010
   3  * Author: Mattias Nilsson <mattias.i.nilsson@stericsson.com> for ST Ericsson.
   4  * License terms: GNU General Public License (GPL) version 2
   5  */
   6
   7 #include <linux/err.h>
   8 #include <linux/module.h>
   9 #include <linux/platform_device.h>
  10 #include <linux/mfd/abx500.h>
  11 #include <linux/mfd/abx500/ab8500.h>
  12 #include <linux/mfd/abx500/ab8500-sysctrl.h>
  13
  14 static struct device *sysctrl_dev;
  15
  16 static inline bool valid_bank(u8 bank)
  17 {
  18         return ((bank == AB8500_SYS_CTRL1_BLOCK) ||
  19                 (bank == AB8500_SYS_CTRL2_BLOCK));
  20 }
  21
  22 int ab8500_sysctrl_read(u16 reg, u8 *value)
  23 {
  24         u8 bank;
  25
  26         if (sysctrl_dev == NULL)
  27                 return -EAGAIN;
  28
  29         bank = (reg >> 8);
  30         if (!valid_bank(bank))
  31                 return -EINVAL;
  32
  33         return abx500_get_register_interruptible(sysctrl_dev, bank,
  34                 (u8)(reg & 0xFF), value);
  35 }
  36
  37 int ab8500_sysctrl_write(u16 reg, u8 mask, u8 value)
  38 {
  39         u8 bank;
  40
  41         if (sysctrl_dev == NULL)
  42                 return -EAGAIN;
  43
  44         bank = (reg >> 8);
  45         if (!valid_bank(bank))
  46                 return -EINVAL;
  47
  48         return abx500_mask_and_set_register_interruptible(sysctrl_dev, bank,
  49                 (u8)(reg & 0xFF), mask, value);
  50 }
  51
  52 static int __devinit ab8500_sysctrl_probe(struct platform_device *pdev)
  53 {
  54         sysctrl_dev = &pdev->dev;
  55         return 0;
  56 }
  57
  58 static int __devexit ab8500_sysctrl_remove(struct platform_device *pdev)
  59 {
  60         sysctrl_dev = NULL;
  61         return 0;
  62 }
  63
  64 static struct platform_driver ab8500_sysctrl_driver = {
  65         .driver = {
  66                 .name = "ab8500-sysctrl",
  67                 .owner = THIS_MODULE,
  68         },
  69         .probe = ab8500_sysctrl_probe,
  70         .remove = __devexit_p(ab8500_sysctrl_remove),
  71 };
  72
  73 static int __init ab8500_sysctrl_init(void)
  74 {
  75         return platform_driver_register(&ab8500_sysctrl_driver);
  76 }
  77 subsys_initcall(ab8500_sysctrl_init);
  78
  79 MODULE_AUTHOR("Mattias Nilsson <mattias.i.nilsson@stericsson.com");
  80 MODULE_DESCRIPTION("AB8500 system control driver");
  81 MODULE_LICENSE("GPL v2");