i2c_dm.c 1.8 KB

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  1. /*
  2. * Copyright (c) 2006-2022, RT-Thread Development Team
  3. *
  4. * SPDX-License-Identifier: Apache-2.0
  5. *
  6. * Change Logs:
  7. * Date Author Notes
  8. * 2022-12-06 GuEe-GUI first version
  9. */
  10. #include <rtdevice.h>
  11. #define DBG_TAG "i2c.dm"
  12. #define DBG_LVL DBG_INFO
  13. #include <rtdbg.h>
  14. #ifdef RT_USING_OFW
  15. static void i2c_parse_timing(struct rt_ofw_node *dev_np, const char *propname,
  16. rt_uint32_t *out_value, rt_uint32_t def_value, rt_bool_t use_defaults)
  17. {
  18. if (rt_ofw_prop_read_u32(dev_np, propname, out_value) && use_defaults)
  19. {
  20. *out_value = def_value;
  21. }
  22. }
  23. rt_err_t i2c_timings_ofw_parse(struct rt_ofw_node *dev_np, struct i2c_timings *timings,
  24. rt_bool_t use_defaults)
  25. {
  26. rt_ubase_t def;
  27. rt_bool_t udef = use_defaults;
  28. struct i2c_timings *t = timings;
  29. i2c_parse_timing(dev_np, "clock-frequency", &t->bus_freq_hz, I2C_MAX_STANDARD_MODE_FREQ, udef);
  30. def = t->bus_freq_hz <= I2C_MAX_STANDARD_MODE_FREQ ? 1000 : t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120;
  31. i2c_parse_timing(dev_np, "i2c-scl-rising-time-ns", &t->scl_rise_ns, def, udef);
  32. def = t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120;
  33. i2c_parse_timing(dev_np, "i2c-scl-falling-time-ns", &t->scl_fall_ns, def, udef);
  34. i2c_parse_timing(dev_np, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns, 0, udef);
  35. i2c_parse_timing(dev_np, "i2c-sda-falling-time-ns", &t->sda_fall_ns, t->scl_fall_ns, udef);
  36. i2c_parse_timing(dev_np, "i2c-sda-hold-time-ns", &t->sda_hold_ns, 0, udef);
  37. i2c_parse_timing(dev_np, "i2c-digital-filter-width-ns", &t->digital_filter_width_ns, 0, udef);
  38. i2c_parse_timing(dev_np, "i2c-analog-filter-cutoff-frequency", &t->analog_filter_cutoff_freq_hz, 0, udef);
  39. return RT_EOK;
  40. }
  41. #endif /* RT_USING_OFW */