i2c-mux.h 2.2 KB

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  1. /*
  2. *
  3. * i2c-mux.h - functions for the i2c-bus mux support
  4. *
  5. * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
  6. * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
  7. * Michael Lawnick <michael.lawnick.ext@nsn.com>
  8. *
  9. * This program is free software; you can redistribute it and/or modify
  10. * it under the terms of the GNU General Public License as published by
  11. * the Free Software Foundation; either version 2 of the License, or
  12. * (at your option) any later version.
  13. *
  14. * This program is distributed in the hope that it will be useful,
  15. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17. * GNU General Public License for more details.
  18. *
  19. * You should have received a copy of the GNU General Public License
  20. * along with this program; if not, write to the Free Software
  21. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  22. * MA 02110-1301 USA.
  23. */
  24. #ifndef _LINUX_I2C_MUX_H
  25. #define _LINUX_I2C_MUX_H
  26. #ifdef __KERNEL__
  27. #include <linux/bitops.h>
  28. struct i2c_mux_core {
  29. struct i2c_adapter *parent;
  30. struct device *dev;
  31. bool mux_locked;
  32. void *priv;
  33. int (*select)(struct i2c_mux_core *, u32 chan_id);
  34. int (*deselect)(struct i2c_mux_core *, u32 chan_id);
  35. int num_adapters;
  36. int max_adapters;
  37. struct i2c_adapter *adapter[0];
  38. };
  39. struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent,
  40. struct device *dev, int max_adapters,
  41. int sizeof_priv, u32 flags,
  42. int (*select)(struct i2c_mux_core *, u32),
  43. int (*deselect)(struct i2c_mux_core *, u32));
  44. /* flags for i2c_mux_alloc */
  45. #define I2C_MUX_LOCKED BIT(0)
  46. static inline void *i2c_mux_priv(struct i2c_mux_core *muxc)
  47. {
  48. return muxc->priv;
  49. }
  50. struct i2c_adapter *i2c_root_adapter(struct device *dev);
  51. /*
  52. * Called to create an i2c bus on a multiplexed bus segment.
  53. * The chan_id parameter is passed to the select and deselect
  54. * callback functions to perform hardware-specific mux control.
  55. */
  56. int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
  57. u32 force_nr, u32 chan_id,
  58. unsigned int class);
  59. void i2c_mux_del_adapters(struct i2c_mux_core *muxc);
  60. #endif /* __KERNEL__ */
  61. #endif /* _LINUX_I2C_MUX_H */