工具/软件:Linux
AM335x 上的 PWM ecap0启用:
DTS 文件如下所示:
epwms0{(&E)
状态="正常";
ecap0:ECAP@48300100{
STATUS ="禁用";
pinctrl-names ="default";
兼容="ti、am33xx-ecap";
#PWM-Cells =<3>;
REG =<0x48300100 0x80>;
中断=<31>;
中断名称="ecap0";
ti、hwmods ="ecap0";
pinctrl-0 =<&ecap0_PINs>;
};
ehrpwm0:PWM@48300200{
状态="正常";
ti、hwmds ="ehrpwm0";
pinctrl-0 =<&ehrpwm0_PINs>;
};
};
ehrpwm0_pins:backlight_pins{
pinctrl-single、pins =<
AM33XX_IOPAD (0x964、MUX_MODE0)
>;
};
ecap0_pins:backlight_ecap0_pins{
pinctrl-single、pins =<
// AM33XX_IOPAD (0x964、MUX_MODE0)
>;
};
使用的导线链接:
http://processors.wiki.ti.com/index.php/Linux_Core_PWM_User%27s_Guide
在终端用户级别:
申请器件:
root@AM335x-EVM:~# echo 0 >/sys/class/pwm/pwmchip0/export
启用/禁用 PWM 通道
root@AM335x-EVM:~# echo 1 >/sys/class/pwm/pwmchip0/pwm0/enable
-sh:echo:write error:invalid arge.
如果周期为1秒,请输入
root@AM335x-EVM:~# echo 1000000000 >/sys /class/pwm/pwmchip0/pwm0/period
[190.492234] ehrpwm 48300200.PWM:_od_fail_runtime_resume:FIXME:缺少 hwmod/OMA_dev 信息
[190.501048]未处理的故障:在0xfa300200上的非线性蚀刻(0x1028)上的外部中止
[190.508758] PgD = da938000
[190.511488][Fa300200]* PgD=48211452 (BAD)
[190.515565]内部错误:1028 [#1]抢占 ARM
[190.520475]链接的模块:BC_example (O) SD_mod USB_storage SCSI_mod USB_f_ACM u_serial USB_f_ECM musb_dsp musb_hdr usbcore)
[190.582465] CPU:0 PID:820 Comm:sh 被污染:G O 4.9.59-ga75d8e9305 #53
[190.590341]硬件名称:通用 AM33XX (平展器件树)
[190.596475]任务:dc698000 task.stack:dacea000
[190.601075] PC 位于 ehrpwm_PWM_config+0x1a8/0x2e8
[190.605907] LR 位于__schedule+0x284/0x5d4
[190.610126]电脑:[ ] LR:[ ] PSR:60010013
[190.610126] sp:dacebdd0 IP:dacebcc0 fp:daceb04
[190.621672] R10:fa300200 R9:dc245d80 R8:dc245d10
[190.626932] r7:00001f00 R6:00000600 R5:00000080 R4:05f5e100
[190.633500] r3:00000000 r2:00000001 r1:00000000 r0:已 ffffffffffed
[190.640074]标志:模式 SVC_32 ISA ARM 段无时 FIQ 上的 nZCv IRQ
[190.647255]控制:10c5387d 表:9a938019 DAC:00000051
[190.653040]进程 sh (pid:820、栈限制= 0xdacea208)
[190.658650]堆栈:(0xdacebdd0至0xdacec000)
[190.663048] bdc0: 00000000 dacebe0c dacebe38
[190.671291] bde0:dc245d80 c0406eb8 dc245da0 00000000 00000000 00000000 dacebe2c dace08
[190.679532] be00:c0405be0 c0406ec4 00000000 da92038c dc245d80 0000000b 00000000 00000000
[190.687774] BE20:dacebe64 dacebe30 c0406274 c0405ad4 c0990aa0 3b9aca00 3b9aca00 00000000
[190.696015] be40:00000000 c040620c 0000000b dacebf78 d71d0a00 dacebe7c dacebe68
[190.704257] be60:c04ec960 c0406218 c04ec940 0000000b dacebe94 dacebe80 c0281e4c c04ec94c
[190.712498] be80:d71d0d80 0000000b dacebed4 dacebe98 c02815b4 c0281e10 00000000 00000000
[190.720739] bea0:c02230d4 d71d0d8c dc571d10 da90a3c0 c02814bc dacebf78 0000000b 00000000
[190.728979] bec0:0000000b 00000000 dacebf44 dacebed8 c02120dc c02814c8 00000000 0000000a
[190.737220] bee0:dabdb900 daf65040 0000000a 00000400 00000000 da8e9840 00000000 da8e9840
[190.745462] bf00:dacebf2c dacebf10 c0210378 c0214a08 00000001 dabdb900 da8e9840 00000200
[190.753703] bf20:0000000b da90a3c0 000ed10 dacebf78 00000000 0000000b dacebf74 dacebf48
[190.761944] bf40:c0212fb0 c02120b4 dacebf74 dacebf58 da90a3c0 da90a3c0 00000000 00000000
[190.770185] bf60:000ed10 0000000b dacebfa4 dacebf78 c0213db0 c0212f10 00000000 00000000