Adding PWM Commands (v4)
Thanks again all for comments so far.
Changes in v4:
- rework set/get into single command
- add more cmd arg checking
Changes in v3:
- fix minor typos
- remove unused 'error' var in pwm_get
Changes in v2:
- remove '-n' option to specify device by number
- fix freeing resources on all return paths
- add pwm_get command
PATCH v4 1/2 commands: add pwm manipulation command
This introduces a command to set parameters for a pwm device.
Signed-off-by Marc Reilly <[email protected]>
--- commands/Kconfig | 12 +++ commands/Makefile | 1 + commands/pwm.c | 199 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 212 insertions(+) create mode 100644 commands/pwm.c
commands/Kconfig +12 -0
@@ -1929,6 +1929,18 @@ config CMD_I2C -w use word (16 bit) wide access -v verbose +config CMD_PWM + bool + depends on PWM + prompt "PWM commands: pwm" + help + pwm - set or show pwm state + + Usage: pwm [dDPfwisv] + + Controls the pwm values such as period and duty cycle, or shows + the current values. + config CMD_LED bool depends on LED
commands/Makefile +1 -0
@@ -69,6 +69,7 @@ obj-$(CONFIG_CMD_GPIO) += gpio.o obj-$(CONFIG_CMD_UNCOMPRESS) += uncompress.o obj-$(CONFIG_CMD_I2C) += i2c.o obj-$(CONFIG_CMD_SPI) += spi.o +obj-$(CONFIG_CMD_PWM) += pwm.o obj-$(CONFIG_CMD_MIPI_DBI) += mipi_dbi.o obj-$(CONFIG_CMD_UBI) += ubi.o obj-$(CONFIG_CMD_UBIFORMAT) += ubiformat.o
commands/pwm.c new file +199 -0
199 lines not on this page · raw message
Signature · 1 line
2.35.3
Re: [PATCH v4 1/2] commands: add pwm manipulation command
Hi Marc,
I applied this with some small changes.
Quoted 34 lines · Marc Reilly
commands/pwm.c new file +34
-0+static int do_pwm_cmd (int argc,char *argv[]) +{ +struct pwm_device *pwm =NULL ; +struct pwm_state state, orig_state; +int error =0 ; +char *devname =NULL ; +int duty =-1 , period =-1 ; +int freq =-1 , width =-1 ; +bool invert_polarity = false, stop = false; +bool use_default_width = false; +bool verbose = false; +int opt; + +while ((opt =getopt (argc, argv,"d:D:P:f:w:F:isv" )) >0 ) { +switch (opt) { +case 'd' : + devname = optarg; +break ; +case 'D' : + duty =simple_strtol (optarg,NULL ,0 ); +break ; +case 'P' : + period =simple_strtol (optarg,NULL ,0 ); +break ; +case 'F' : +/* convenience option for changing frequency without +* having to specify duty width */ + use_default_width = true; +/* fallthrough */ +case 'f' : + freq =simple_strtol (optarg,NULL ,0 ); +break ; +case 'w' : + width =simple_strtol (optarg,NULL ,0 );
commands/pwm.c line 67
Quoted 10 lines
commands/pwm.c new file +10
-0+break ; +case 'i' : + invert_polarity = true; +break ; +case 's' : + stop = true; +break ; +case 'v' : + verbose = true; +break ;
default: return COMMAND_ERROR_USAGE;
Quoted 30 lines
commands/pwm.c new file +30
-0+ } + } + +if (!devname) { +printf (" need to specify a device\n" ); +return COMMAND_ERROR_USAGE ; + } +if ((freq ==0 ) || (period ==0 )) { +printf (" period or freqency needs to be non-zero\n" ); +return COMMAND_ERROR_USAGE ; + } +if (freq >=0 && period >=0 ) { +printf (" specify period or frequency, not both\n" ); +return COMMAND_ERROR_USAGE ; + } +if (duty >=0 && width >=0 ) { +printf (" specify duty or width, not both\n" ); +return COMMAND_ERROR_USAGE ; + } +if (width >100 ) { +printf (" width (%% duty cycle) can't be more than 100%%\n" ); +return COMMAND_ERROR_USAGE ; + } + + pwm =pwm_request (devname); +if (!pwm) { +printf (" pwm device %s not found\n" , devname); +return -ENODEV ; + } +
commands/pwm.c line 107
Quoted 10 lines
commands/pwm.c new file +10
-0+pwm_get_state (pwm, &state); + +/* argc will be at least 3 with a valid devname */ +if (verbose || (argc <=3 )) { +printf ("pwm params for '%s':\n" , devname); +printf (" period : %u (ns)\n" , state.period_ns); +printf (" duty : %u (ns)\n" , state.duty_ns); +printf (" enabled : %d\n" , state.p_enable); +printf (" polarity : %s\n" , state.polarity ==0 ?"Normal" :"Inverted" ); +printf (" freq : %lu (Hz)\n" ,HZ_FROM_NANOSECONDS (state.period_ns));
This results in a division by zero crash on a disabled PWM. I changed this to:
if (state.period_ns)
printf(" freq : %lu (Hz)\n", HZ_FROM_NANOSECONDS(state.period_ns));
else
printf(" freq : -\n");commands/pwm.c line 187
Quoted 5 lines
commands/pwm.c new file +5
-0+BAREBOX_CMD_HELP_OPT("-d string", "device name (eg 'pwm0')") +BAREBOX_CMD_HELP_OPT("-D number", "duty cycle (ns)") +BAREBOX_CMD_HELP_OPT("-P number", "period (ns)") +BAREBOX_CMD_HELP_OPT("-f number", "frequency (Hz)") +BAREBOX_CMD_HELP_OPT ("-w number" ,"duty cycle (%) - the on 'width' of each cycle" )
Replaced 'number' with <duty_ns> and similar.
Sascha
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PATCH v4 2/2 include: pwm: minor function doc fix for pwm_set_relative_duty_cycle()
In reply to Marc ReillySigned-off-by Marc Reilly <[email protected]>
--- include/pwm.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
include/pwm.h +1 -1
@@ -71,7 +71,7 @@ unsigned int pwm_get_period(struct pwm_device *pwm);* @scale: scale in which @duty_cycle is expressed * * This functions converts a relative into an absolute duty cycle (expressed -* in nanoseconds), and puts the result in state->duty_cycle. +* in nanoseconds), and puts the result in state->duty_ns. * * For example if you want to configure a 50% duty cycle, call: *
Signature · 1 line
2.35.3