modify touch pad read function
The touch pad read function taks too much time within spin lock waiting for the "done bit". (about 7.6ms as we tested)
So we try to use a mutex on the touch read function and any other functions might change the "done bit".
See merge request !543
This issue is reported from https://github.com/espressif/esp-idf/issues/304.
We found that when we operate the hw command registers in I2C struct, sometimes the behaviour would be different in DEBUG/RELEASE optimisation level:
The code looks like this:
I2C[i2c_num]->command[p_i2c->cmd_idx].byte_num -= 0;
In DEBUG configuration:
I2C[i2c_num]->command[p_i2c->cmd_idx].byte_num -= 0;
400f3ab0: 3388 l32i.n a8, a3, 12
400f3ab2: 14c882 addi a8, a8, 20
400f3ab5: a08840 addx4 a8, a8, a4
400f3ab8: 0020c0 memw
400f3abb: 2898 l32i.n a9, a8, 8
400f3abd: 0020c0 memw
400f3ac0: 28b8 l32i.n a11, a8, 8
400f3ac2: 74a090 extui a10, a9, 0, 8
400f3ac5: 00af92 movi a9, 0xffffff00
400f3ac8: 109b90 and a9, a11, a9
400f3acb: 2099a0 or a9, a9, a10
400f3ace: 0020c0 memw
400f3ad1: 2899 s32i.n a9, a8, 8
In RELEASE configuration:
I2C[i2c_num]->command[p_i2c->cmd_idx].byte_num -= 0;
400f2ba2: 580572 l8ui a7, a5, 88
400f2ba5: 747070 extui a7, a7, 0, 8
400f2ba8: 0020c0 memw
400f2bab: 584572 s8i a7, a5, 88
Looks like the compiler will make it a 8bit operation after optimisation.
But the register value changes from 0x901 to 0x101.
After this 8-bit optimisation, the 11th bit changed from 1 to zero, which caused this error.
We are still trying to find out why that happens, because there might be some risk when operating the register struct.
This is a workaround to avoid "-=" operation on I2C register struct fields.
1. Add low speed channels for LEDC module.
2. Improve fade object allocate mechanism.
3. Improve ledc example, add 2 low speed channels in example.
4. Remove debug code
5. Improve the register bit field name of slow clock.
The touch pad read function taks too much time within spin lock waiting for the "done bit". (about 7.6ms as we tested)
So we try to use a mutex on the touch read function and any other functions might change the "done bit".
1. add fading functions.
2. clear up ledc.c and ledc.h
3. update api doc.
4. add ledc example
5. edit ledc.rst and add readme for example code.
6. add s_ prefix for static global values.
7. add mutex for fade functions
8. minor changes according to the comments.
2. update example comments and other minor changes
3. rename API: i2c_cmd_link_create/i2c_cmd_link_delete (+4 squashed commits)
Squashed commits:
[2e0ac3e] 1. coding style: add one space after condition key words.
2. modify i2c.h, use gpio_num_t instead of int, improve comments of return values
3. add i2c index in index.rst
4. add readme for i2c example
[4991d92] update i2c.doc
[88b672e] driver: i2c
1. add mux and spin lock to run in a thread-safe way.
2. modify example code
[4eb15fe] driver: i2c code
1. add i2c master code
2. add i2c slave code
3. add i2c example code
4. add DRAM_ATTR for I2C array
bugfix: uart event mismatch
Fix bug of uart frame error and parity error interrupt mismatch in driver code, which will cause the corresponding interrupt can not be cleared correctly, and will finally cause a interrupt watch dog.
See merge request !335
GPIO driver: add per-pin interrupt handlers
1. add ISR handler apis so that users of different layers can hook their own isr handler on different GPIO.
Audio project has different software layers, they need different gpio isr handler for layer instead of processing all GPIO interrupts in one handler.
If this kind of calling a handler from isr is not proper, please kindly point out.
2. add gpio example code.
3. update gpio doc.
See merge request !345
1. add ISR handler apis so that users of different layers can hook their own isr handler on different GPIO.
Audio project has different software layers, they need different gpio isr handler for layer instead of processing all GPIO interrupts in one handler.
If this kind of calling a handler from isr is not proper, please kindly point out.
2. add gpio example code.
3. improve gpio.rst
4. add readme for gpio example
Squashed commits:
[278e50f] update: GPIO
1. coding style, add a space between conditional or loop keyword and an opening paren.
2. modify some return value and doc
3. use printf in example code
Squashed commits:
[efb23bb] minor change of comment
