Linux kernel header file macro about S3C2410 gpio

Last Update:2018-12-03 Source: Internet

Author: User

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Linux kernel header file macro about S3C2410 gpio

1. gpio register Definition
1. # define gpcon (x) _ reg2 (0x56000000, (x) * 0x10)
This statement defines the control register of gpio 2410. Note that the _ reg2 parameter is the physical address of the register. This physical address is converted to a virtual address through the _ reg2 macro, compare the 2410 manual to get the corresponding relationship:
Gpcon (1) ------ port a 0x56000000
Gpcon (2) ------ port B 0x56000010
Gpcon (3) ------ port C 0x56000020
....
....
....
Gpcon (8) ------ port H 0x56000070
2. # define gpdat (x) _ reg2 (0x56000004, (x) * 0x10)
This statement defines the 2410 gpio data register. The definition method is the same as that of the gpcon macro.
Gpdat (1) ------ port a 0x56000004
Gpdat (2) ------ port B 0x56000014
Gpdat (3) ------ port C 0x56000024
....
....
....
Gpdat (8) ------ port H 0x56000074
3. # define gpup (x) _ reg2 (0x56000008, (x) * 0x10)
This statement defines the up-pull resistance mask/activation register of the 2410 gpio, which is defined in the same way as the gpcon macro.
Gpup (1) ------ port a 0x56000008
Gpup (2) ------ port B 0x56000018
Gpup (3) ------ port C 0x56000028
....
....
....
Gpup (8) ------ port H 0x56000078
Ii. gpio port number Definition
Use gpio_g12 to describe how to define the port number of the IO port in the kernel header file $(kernel_include)/ASM-arm/ARCH/S3C2410. h. Defining gpio ports mainly involves the following macros:
# Define make_gpio_num (p, O) (P <gpio_port_shiftt) | (O <gpio_ofs_shift) # define gpio_g12 make_gpio_num (portg_ofs, 12) the swap value is 8, represents the displacement of the gpio group number in the whole gpio port number (such as gpio_g12) Field
The value of gpio_ofs_shift is 0, which indicates the displacement of the Offset number in the gpio group in the whole gpio port number (such as gpio_g12) field.
There are 117 input/output port pins in S3C2410. It can be divided into the following eight groups:
-Port A (GPA): 23-output port # define porta_ofs 0
-Port B (GPB): 11-input/output port # define portb_ofs 1
-Port C (GPC): 16-input/output port # define portc_ofs 2
-Port D (GPD): 16-input/output port # define portd_ofs 3
-Port E (GPE): 16-input/output port # define porte_ofs 4
-Port F (GPF): 8-input/output port # define portf_ofs 5
-Port g (GPG): 16-input/output port # define portg_ofs 6
-Port H (gph): 11-input/output port # define porth_ofs 7

Gpg12 belongs to the G group and the intra-group offset is 12. From the two macro definitions above, we can clearly see the structure of gpio_g12:

Figure 1 Structure of gpio port number
There are eight groups of ports. From the macro definition above, we can see that the port group number P ranges from 0 ~ 7. The Group offset groups are different. Port A has 23 output ports, so the intra-group offset o is 0 ~ 22. Port G has 16 Io ports, and its intra-group offset o is 0 ~ 15. gpio in other groups and so on.
Iii. write_gpio_bit (x, v) Macro Analysis
Write_gpio_bit macro imports two parameters, the first is the gpio port number, such as gpio_g12; the second parameter is 1 or 0, set the high level or low level output for the corresponding IO port. The specific macro scale is as follows:
# Define write_gpio_bit (x, v )/
({/
Gpdat (grab_port (X) & = ~ (0x1 X )));/
Gpdat (grab_port (x) | = (v) X )));/
})
The grab_port macro parameter is the gpio port number. The function is to parse the group number from the gpio port number. The specific definition is as follows:
# Define grab_port (x) & gpio_port_mask)> gpio_port_shiftt)
The gpio_port_mask is the group number mask and its value is 0x0000ff00, which can be seen in figure 1.
The grab_ofs macro is similar to the grab_port macro. Its function is to parse the intra-group offset from the gpio Port:
# Define grab_ofs (x) & gpio_ofs_mask)> gpio_ofs_shift)
The offset value mask gpio_ofs_mask = 0x000000ff.
Now we can analyze the write_gpio_bit (gpio_g12, 1) statement based on the preceding description: The macro definition of gpio_g12 can calculate the value of 0x0000060c, grab_port (gpio_g12) after parsing, the operated Io belongs to the G group and the group number is 6. The grab_ofs (gpio_g12) resolves the IO port to the 12th pins (starting from 0) of the G group, which is gpg12, the expression value is 12. Write_gpio_bit (gpio_g12, 1) is equivalent to the following two statements:
Gpdat (6) & = ~ (0x112); // The 12th-bit clearing of the gpgdat register
Gpdat (6) | = 112; // write '1' to the 12th-bit gpgdat register'
At this point, we know that the write_gpio_bit (gpio_g12, 1) statement is to pull the gpg12 pin to a high level.
Iv. set_gpio_ctrl (x) Macro Analysis
# Define set_gpio_ctrl (X )/
({Gpcon (grab_port (X) & = ~ (0x3
Gpcon (grab_port (x) | = (grab_mode (X)
Gpup (grab_port (X) & = ~ (1
Gpup (grab_port (x) | = (grab_pullup (x ))
After the write_gpio_bit macro is analyzed, it is easy to see set_gpio_ctrl! In its macro development, only grab_mode (X) and grab_pullup (x) are added) the mode of the IO port and the Enable/shield up resistance of the port are parsed from parameter x respectively. It is worth noting that the parameter X of set_gpio_ctrl not only indicates the gpio port number, but also has the mode status and pull-up resistance control information. The structure of the parameter X is as follows:

Figure 2 parameter field structure of set_gpio_ctrl

The low 16-bit value is the gpio port number described above. The R field in the high 16-bit value is used to shield/enable the pull-up resistance function of the IO port. R = 0: enables the pull-up resistor; r = 1: the pull-up resistor is invalid. The m field is used to set the operating mode of the IO port. m = 0 indicates that the IO port is the input port, M = 1 indicates that the IO port is the output port, and m = 2 indicates that function 1 is optional; M = 3. Optional; function 2.
The set_gpio_ctrl macro is to write the gpxcon (X is ~ H) To set the IO port mode (each bit of gpacon controls an IO port, while gpbcon ~ Gphcon is a two-bit mode that controls an I/O port. By writing gpxup (X is ~ H) To determine whether to enable the pull-up resistance. The typical set_gpio_ctrl call method is as follows:
Set_gpio_ctrl (gpio_mode_out | gpio_pullup_dis | gpio_g12 );
This statement sets gpg12 to the output mode without using the port pull-up resistance.
5. Conclusion
The preceding section analyzes $(linux_kernel_include)/ASM-arm/ARCH/S3C2410 in combination with "S3C2410X 32-bit Proteus microprocessor User's Manual. several macros defined in H to operate on 2410gpio, in addition to the several macros mentioned in this article, include read_gpio_bit (x), read_gpio_reg (x), write_gpio_reg (x, v), etc, the implementation method is similar to the above. I will not go into details here! //////////////////////////////////////// ///////# Define gpcon (x) _ reg2 (0x56000000, (x) * 0x10) # define gpdat (x) _ reg2 (0x56000004, (x) * 0x10) # define gpup (x) _ reg2 (0x56000008, (x) * 0x10) # define gpio_ofs_shift0 # define gpio_port_shiftt8 # define gpio_pullup_shift16 # define condition # define gpio_port_mask0x0000ff00 # define gpio_pullup_mask0x00ff0000 # defi Ne gpio_mode_mask0xff000000 # define gpio_mode_in (0 <gpio_mode_shift) # define gpio_mode_out (1 <gpio_mode_shift) # define transform (2 <gpio_mode_shift) # define transform (3 <gpio_mode_shift) # define gpio_pullup_en (0 <gpio_pullup_shift) # define gpio_pullup_dis (1 <gpio_pullup_shift) # define porta_ofs0 # define portb_ofs1 # define portc_o Fs2 # define portd_ofs3 # define porte_ofs4 # define portf_ofs5 # define portg_ofs6 # define porth_ofs7 # define make_gpio_num (p, o) (P <gpio_port_shiftt) | (O <gpio_ofs_shift) # define grab_mode (x) & gpio_mode_mask)> gpio_mode_shift) # define grab_pullup (x) & gpio_pullup_mask)> gpio_pullup_shift) # define grab_port (x) & gpio_port_mask)> Gpio_port_shiftt) # define grab_ofs (x) & gpio_ofs_mask)> gpio_ofs_shift) # define set_gpio_ctrl (X) / ({gpcon (grab_port (X) & = ~ (0x3 <(grab_ofs (x) * 2);/ gpcon (grab_port (x) | = (grab_mode (X) <(grab_ofs (x) * 2);/ gpup (grab_port (X) & = ~ (1 <grab_ofs (X);/ gpup (grab_port (X) | = (grab_pullup (x )) <grab_ofs (x) ;}) # define set_gpio_pullup (X)/ ({gpup (grab_port (X ))) & = ~ (1 <grab_ofs (X);/ gpup (grab_port (X) | = (grab_pullup (x )) <grab_ofs (x) ;}) # define set_gpio_pullup_user (x, v)/ ({gpup (grab_port (X ))) & = ~ (1 <grab_ofs (X);/ gpup (grab_port (X) | = (V) <grab_ofs (x) ;}) # define set_gpio_mode (X)/ ({gpcon (grab_port (X ))) & = ~ (0x3 <(grab_ofs (x) * 2);/ gpcon (grab_port (X ))) | = (grab_mode (x) <(grab_ofs (x) * 2);}) # define set_gpio_mode_user (x, V) / ({gpcon (grab_port (X) & = ~ (0x3 <(grab_ofs (x) * 2);/ gpcon (grab_port (X) | = (V) <(grab_ofs (x) * 2);}) # define set_gpioa_mode (X) / ({gpcon (grab_port (X) & = ~ (0x1 <grab_ofs (X);/ gpcon (grab_port (X) | = (grab_mode (x )) <grab_ofs (x) ;}) # define read_gpio_bit (x) (gpdat (grab_port (X ))) & (1 <grab_ofs (X)> grab_ofs (X) # define read_gpio_reg (X) (gpdat (grab_port (X) # define write_gpio_bit (x, v)/ ({gpdat (grab_port (X ))) & = ~ (0x1 <grab_ofs (X);/ gpdat (grab_port (X) | = (V) <grab_ofs (x) ;}) # define write_gpio_reg (x, V) (gpdat (grab_port (X) = (V )) # define partition (porta_ofs, 0) # define partition (porta_ofs, 1) # define gpio_a2make_gpio_num (porta_ofs, 2) # define gpio_a3make_gpio_num (porta_ofs, 3) # define gpio_a4make_gpio_num (porta_ofs, 4) # define partition (porta_ofs, 5) # define gpio_a6make_gpio_num (porta_ofs, 6) # define gpio_a7make_gpio_num (porta_ofs, 7) # define partition (porta_ofs, 8) # define partition (porta_ofs, 9) # define partition (porta_ofs, 10) # define gpio_a11make_gpio_num (porta_ofs, 11) # define partition (porta_ofs, 12) # define partition (porta_ofs, 13) # define gpio_a14make_gpio_num (porta_ofs, 14) # define partition (porta_ofs, 15) # define partition (porta_ofs, 16) # define gpio_a17make_gpio_num (porta_ofs, 17) # define partition (porta_ofs, 18) # define partition (porta_ofs, 19) # define gpio_a20make_gpio_num (porta_ofs, 20) # define partition (porta_ofs, 21) # define gpio_a22make_gpio_num (porta_ofs, 22) # define partition (portb_ofs, 0) # define partition (portb_ofs, 1) # define gpio_b2make_gpio_num (portb_ofs, 2) # define gpio_b3make_gpio_num (portb_ofs, 3) # define gpio_b4make_gpio_num (portb_ofs, 4) # define partition (portb_ofs, 5) # define gpio_b6make_gpio_num (portb_ofs, 6) # define gpio_b7make_gpio_num (portb_ofs, 7) # define partition (portb_ofs, 8) # define gpio_b9make_gpio_num (portb_ofs, 9) # define partition (portb_ofs, 10) # define gpio_c0make_gpio_num (portc_ofs, 0) # define gpio_c1make_gpio_num (portc_ofs, 1) # define gpio_c2make_gpio_num (portc_ofs, 2) # define partition (portc_ofs, 3) # define gpio_c4make_gpio_num (portc_ofs, 4) # define gpio_c5make_gpio_num (portc_ofs, 5) # define gpio_c6make_gpio_num (portc_ofs, 6) # define partition (portc_ofs, 7) # define gpio_c8make_gpio_num (portc_ofs, 8) # define gpio_c9make_gpio_num (portc_ofs, 9) # define partition (portc_ofs, 10) # define gpio_c11make_gpio_num (portc_ofs, 11) # define partition (portc_ofs, 12) # define gpio_c13make_gpio_num (portc_ofs, 13) # define partition (portc_ofs, 14) # define gpio_c15make_gpio_num (portc_ofs, 15) # define partition (portd_ofs, 0) # define Export (portd_ofs, 1) # define gpio_d2make_gpio_num (portd_ofs, 2) # define gpio_d3make_gpio_num (portd_ofs, 3) # define gpio_d4make_gpio_num (portd_ofs, 4) # define partition (portd_ofs, 5) # define gpio_d6make_gpio_num (portd_ofs, 6) # define Export (portd_ofs, 7) # define gpio_d8make_gpio_num (portd_ofs, 8) # define gpio_d9make_gpio_num (portd_ofs, 9) # define gpio_d10make_gpio_num (portd_ofs, 10) # define partition (portd_ofs, 11) # define gpio_d12make_gpio_num (portd_ofs, 12) # define gpio_d13make_gpio_num (portd_ofs, 13) # define Export (portd_ofs, 14) # define gpio_d15make_gpio_num (portd_ofs, 15) # define partition (porte_ofs, 0) # define partition (porte_ofs, 1) # define gpio_e2make_gpio_num (porte_ofs, 2) # define gpio_e3make_gpio_num (porte_ofs, 3) # define partition (porte_ofs, 4) # define partition (porte_ofs, 5) # define gpio_e6make_gpio_num (porte_ofs, 6) # define partition (porte_ofs, 7) # define partition (porte_ofs, 8) # define partition (porte_ofs, 9) # define partition (porte_ofs, 10) # define gpio_e11make_gpio_num (porte_ofs, 11) # define partition (porte_ofs, 12) # define partition (porte_ofs, 13) # define gpio_e14make_gpio_num (porte_ofs, 14) # define partition (porte_ofs, 15) # define gpio_f0make_gpio_num (portf_ofs, 0) # define partition (portf_ofs, 1) # define gpio_f2make_gpio_num (portf_ofs, 2) # define gpio_f3make_gpio_num (portf_ofs, 3) # define partition (portf_ofs, 4) # define gpio_f5make_gpio_num (portf_ofs, 5) # define partition (portf_ofs, 6) # define gpio_f7make_gpio_num (portf_ofs, 7) # define gpio_g0make_gpio_num (portg_ofs, 0) # define transform (portg_ofs, 1) # define gpio_g2make_gpio_num (portg_ofs, 2) # define gpio_g3make_gpio_num (portg_ofs, 3) # define gpio_g4make_gpio_num (portg_ofs, 4) # define partition (portg_ofs, 5) # define gpio_g6make_gpio_num (portg_ofs, 6) # define Export (portg_ofs, 7) # define gpio_g8make_gpio_num (portg_ofs, 8) # define Export (portg_ofs, 9) # define gpio_g10make_gpio_num (portg_ofs, 10) # define gpio_g11make_gpio_num (portg_ofs, 11) # define gpio_g12make_gpio_num (portg_ofs, 12) # define Export (portg_ofs, 13) # define gpio_g14make_gpio_num (portg_ofs, 14) # define partition (portg_ofs, 15) # define partition (porth_ofs, 0) # define gpio_h1make_gpio_num (porth_ofs, 1) # define gpio_h2make_gpio_num (porth_ofs, 2) # define partition (porth_ofs, 3) # define gpio_h4make_gpio_num (porth_ofs, 4) # define gpio_h5make_gpio_num (porth_ofs, 5) # define partition (porth_ofs, 6) # define gpio_1_make_gpio_num (porth_ofs, 7) # define partition (porth_ofs, 8) # define gpio_h9make_gpio_num (porth_ofs, 9) # define gpio_h10make_gpio_num (porth_ofs, 10) # define gpio_mode_toutgpio_mode_alt0 # define definition # define gpio_mode_lendgpio_mode_alt0 # define tuning # define Tuning # define gpio_mode_vdgpio_mode_alt0 # define tuning # define restart # define gpio_mode_sddatgpio_mode_alt0 # define restart # define tuning # define gpio_mode_eintgpio_mode_alt0 # define gpio_mode_nypongpio_mode_alt1 # define definition # define Definition gpio_mode_tclk_abnormalgpio_mode_alt1 # define restart # define gpio_mode_ LCD _pwrdngpio_mode_alt1

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