无法申请pwm1，这是驱动和log，麻烦看一下，提问很多天了

zzj · 发表于 2016-8-26 14:10:52

/*pt.c*/
#include<linux/pwm.h>
#include<linux/init.h>
#include<linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>

MODULE_LICENSE("GPL");
struct pwm_device * pwm1 = NULL;

static int __init pwm_init(void)
{
      pwm1 = pwm_request(1, "backlight-pwm");
      pwm_config(pwm1, 100000, 500000);
      printk("success\n");
      pwm_enable(pwm1);
      return 0;
}

static void __exit pwm_exit(void)
{
      printk("Exit pwm\n");
}

subsys_initcall(pwm_init);
module_exit(pwm_exit);

firefly@firefly:~/temp/makepra/pwm$ dmesg|tail
[  127.675031] bfa0: 814f4e00 c000da00 be97a6f4 be97a874 00000003 b6f85398 00000000 00000000
[  127.675044] bfc0: be97a6f4 be97a874 814f4e00 0000017b b6f91e08 00000000 b6f81b60 00000000
[  127.675057] bfe0: be97a6a0 be97a690 b6f7c177 b6eec982 80030030 00000003 00000000 00000000
[  127.675081] [<c028a454>] (pwm_config+0x40/0x60) from [<bf03a024>] (pwm_init+0x24/0x50 [pt])
[  127.675105] [<bf03a024>] (pwm_init+0x24/0x50 [pt]) from [<c00086a4>] (do_one_initcall+0x34/0xc8)
[  127.675126] [<c00086a4>] (do_one_initcall+0x34/0xc8) from [<c0080d34>] (do_init_module+0x44/0x168)
[  127.675144] [<c0080d34>] (do_init_module+0x44/0x168) from [<c00819bc>] (SyS_finit_module+0x6c/0x94)
[  127.675164] [<c00819bc>] (SyS_finit_module+0x6c/0x94) from [<c000da00>] (ret_fast_syscall+0x0/0x30)
[  127.675177] Code: e1540003 c3822001 e3520000 1a000005 (e5910010)
[  127.675258] ---[ end trace 0be8b8afa4266cfb ]---
:'(

zzj · 发表于 2016-8-26 14:12:24

还有就是注册pwm-rockchip.c这个驱动文件的具体步骤是什么

leung先森 · 发表于 2016-8-26 14:35:57

zzj 发表于 2016-8-26 14:12
还有就是注册pwm-rockchip.c这个驱动文件的具体步骤是什么

无法申请应该具体看pwm_request报什么问题，一般申请不了都是占用，检查一下dts，那里也用到了pwm1

zzj · 发表于 2016-8-26 14:39:48

leung先森发表于 2016-8-26 14:35
无法申请应该具体看pwm_request报什么问题，一般申请不了都是占用，检查一下dts，那里也用到了pwm1

请问怎么检查dts?检查出来后又要怎么释放？用pwm_free()吗

HelloBirthday · 发表于 2016-8-26 16:11:52

检查dts中是否被占用，disabled掉 pwm_request申请失败表明pwm1已经被占用，你可以直接操作它。若想自己另写驱动，那只能在sts中disabled，然后自己添加

zzj · 发表于 2016-8-28 14:29:49

HelloBirthday 发表于 2016-8-26 16:11
检查dts中是否被占用，disabled掉 pwm_request申请失败表明pwm1已经被占用，你可以直接操作它。若想 ...

我把firefly rk3288.dts里和rk3288.dtsi里的pwm都设置成okay，然后跟你说的一样直接操作pwm1，函数调用顺序是struct pwm_device * pwm1;pwm_enable(pwm1);pwm_config(pwm1,100000,500000);
然后用示波器测pwm1口，结果没有电压变化，还是搞不明白:'(

xaityyy · 发表于 2016-8-28 15:38:18

dmesg给全呀。log太少了

zzj · 发表于 2016-8-28 16:14:34

xaityyy 发表于 2016-8-28 15:38
dmesg给全呀。log太少了

没办法:dizzy:，用的dmesg|tail命令只给这些
用dmesg的话就给的超出屏幕

xaityyy · 发表于 2016-8-28 16:21:51

dmesg | tee dmesg.log。然后发dmesg.log出来。
如果是串口，打开log，就会有log到本地。

长的 · 发表于 2016-8-30 10:16:27

pwm_regulator {
      compatible = "rockchip_pwm_regulator";
      pwms = <&pwm1 0 2000>;
      rockchip,pwm_id= <1>;
      rockchip,pwm_voltage_map= <925000 950000 975000 1000000 1025000 1050000 1075000 1100000 1125000 1150000 1175000 1200000 1225000 1250000 1275000 1300000 1325000 1350000 1375000 1400000>;
      rockchip,pwm_voltage= <1100000>;
      rockchip,pwm_min_voltage= <925000>;
      rockchip,pwm_max_voltage= <1400000>;
      rockchip,pwm_suspend_voltage= <950000>;
      rockchip,pwm_coefficient= <475>;
      regulators {
         #address-cells = <1>;
         #size-cells = <0>;
         pwm_reg0: regulator@0 {
            regulator-compatible = "pwm_dcdc1";
            regulator-name= "vdd_logic";
            regulator-min-microvolt = <925000>;
            regulator-max-microvolt = <1400000>;
            regulator-always-on;
            regulator-boot-on;
         };
      };
};
dts中有这么一段,好像已经占用了pwm1,所以申请会失败,
但是这个是用来做电源控制吗,对应的硬件设备是什么?