i2c-mux.h 2.3 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. unsigned int mux_locked:1;
  32. unsigned int arbitrator:1;
  33. unsigned int gate:1;
  34. void *priv;
  35. int (*select)(struct i2c_mux_core *, u32 chan_id);
  36. int (*deselect)(struct i2c_mux_core *, u32 chan_id);
  37. int num_adapters;
  38. int max_adapters;
  39. struct i2c_adapter *adapter[0];
  40. };
  41. struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent,
  42. struct device *dev, int max_adapters,
  43. int sizeof_priv, u32 flags,
  44. int (*select)(struct i2c_mux_core *, u32),
  45. int (*deselect)(struct i2c_mux_core *, u32));
  46. /* flags for i2c_mux_alloc */
  47. #define I2C_MUX_LOCKED BIT(0)
  48. #define I2C_MUX_ARBITRATOR BIT(1)
  49. #define I2C_MUX_GATE BIT(2)
  50. static inline void *i2c_mux_priv(struct i2c_mux_core *muxc)
  51. {
  52. return muxc->priv;
  53. }
  54. struct i2c_adapter *i2c_root_adapter(struct device *dev);
  55. /*
  56. * Called to create an i2c bus on a multiplexed bus segment.
  57. * The chan_id parameter is passed to the select and deselect
  58. * callback functions to perform hardware-specific mux control.
  59. */
  60. int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
  61. u32 force_nr, u32 chan_id,
  62. unsigned int class);
  63. void i2c_mux_del_adapters(struct i2c_mux_core *muxc);
  64. #endif /* __KERNEL__ */
  65. #endif /* _LINUX_I2C_MUX_H */