* Adding a pwm command @ 2023-05-26 8:23 Marc Reilly 2023-05-26 8:23 ` [RFC PATCH 1/1] commands: add pwm manipulation command Marc Reilly 0 siblings, 1 reply; 3+ messages in thread From: Marc Reilly @ 2023-05-26 8:23 UTC (permalink / raw) To: barebox Hi all, I've been playing around with adding a new board to barebox, and its been a while so I didn't realise that properties could be set on a driver instance directly (eg 'pwm0.enable=1' or 'pwm0.period_ns=10000') I started this pwm_set command, if it's useful (ability to set frequency is helpful) I can submit it properly. It looks like most other commands have doc duplicated in the Kconfig, any other requests? Cheers Marc ^ permalink raw reply [flat|nested] 3+ messages in thread
* [RFC PATCH 1/1] commands: add pwm manipulation command 2023-05-26 8:23 Adding a pwm command Marc Reilly @ 2023-05-26 8:23 ` Marc Reilly 2023-05-26 9:33 ` Johannes Zink 0 siblings, 1 reply; 3+ messages in thread From: Marc Reilly @ 2023-05-26 8:23 UTC (permalink / raw) To: barebox This introduces a command to set parameters for a pwm device. Signed-off-by: Marc Reilly <marc@cpdesign.com.au> --- commands/Kconfig | 11 +++++ commands/Makefile | 1 + commands/pwm.c | 111 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 123 insertions(+) create mode 100644 commands/pwm.c diff --git a/commands/Kconfig b/commands/Kconfig index 4d3ff631a8..6b7d0bfd79 100644 --- a/commands/Kconfig +++ b/commands/Kconfig @@ -1929,6 +1929,17 @@ config CMD_I2C -w use word (16 bit) wide access -v verbose + +config CMD_PWM + bool + depends on PWM + prompt "PWM commands: pwm_set" + help + pwm_set - set pwm state + + Usage: i2c_set - set pwm parameters + + config CMD_LED bool depends on LED diff --git a/commands/Makefile b/commands/Makefile index 98625a0373..011ae59427 100644 --- a/commands/Makefile +++ b/commands/Makefile @@ -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 diff --git a/commands/pwm.c b/commands/pwm.c new file mode 100644 index 0000000000..8a26430e19 --- /dev/null +++ b/commands/pwm.c @@ -0,0 +1,111 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +// SPDX-FileCopyrightText: © 2023 Marc Reilly <marc@cpdesign.com.au> + +/* pwm - pwm commands */ + +#include <common.h> +#include <command.h> +#include <errno.h> +#include <malloc.h> +#include <getopt.h> +#include <pwm.h> + +#define HZ_TO_NANOSECONDS(x) (1000000000UL/(x)) + +static int do_pwm_set(int argc, char *argv[]) +{ + struct pwm_device *pwm = NULL; + struct pwm_state state; + int error = 0; + char namebuf[128]; + char *devname = NULL; + int n = -1, polarity = -1, duty = -1, period = -1, freq = -1, opt; + + while ((opt = getopt(argc, argv, "n:d:D:P:f:i:")) > 0) { + switch (opt) { + case 'n': + n = simple_strtol(optarg, NULL, 0); + break; + 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': + freq = simple_strtol(optarg, NULL, 0); + break; + case 'i': + polarity = simple_strtol(optarg, NULL, 0); + break; + } + } + + if ((n < 0) && !devname) { + printf(" need to specify a device\n"); + return COMMAND_ERROR_USAGE; + } + if ((freq < 0) && (duty < 0) && (period < 0)) { + printf(" need to know some timing info; freq or dury/period\n"); + return COMMAND_ERROR_USAGE; + } + + if (!devname) { + sprintf(namebuf, "pwm%d", n); + } else { + strcpy(namebuf, devname); + } + + pwm = pwm_request(namebuf); + if (!pwm) { + printf("pwm device %s not found\n", namebuf); + return -ENODEV; + } + + pwm_get_state(pwm, &state); + if (polarity >= 0) + state.polarity = polarity; + + if (freq > 0) { + state.p_enable = true; + state.period_ns = HZ_TO_NANOSECONDS(freq); + pwm_set_relative_duty_cycle(&state, 50, 100); + } else if (duty > 0) { + state.p_enable = true; + state.period_ns = period; + state.duty_ns = duty; + } else { + state.p_enable = false; + } + + error = pwm_apply_state(pwm, &state); + + pwm_free(pwm); + + return error; +} + +BAREBOX_CMD_HELP_START(pwm_read) +BAREBOX_CMD_HELP_TEXT("Sets a pwm device parameters.") +BAREBOX_CMD_HELP_TEXT(" Specify the device either by device name or pwm number") +BAREBOX_CMD_HELP_TEXT(" Timings can either be specified via period + duty (on) duration,") +BAREBOX_CMD_HELP_TEXT(" or via frequency.") +BAREBOX_CMD_HELP_TEXT("Options:") +BAREBOX_CMD_HELP_OPT("-d number\t", "device name (eg 'pwm0')") +BAREBOX_CMD_HELP_OPT("-n number\t", "pwm chip number (default 0)") +BAREBOX_CMD_HELP_OPT("-D number\t", "duty cycle (ns)") +BAREBOX_CMD_HELP_OPT("-P number\t", "period (ns)") +BAREBOX_CMD_HELP_OPT("-f number\t", "frequency (Hz)") +BAREBOX_CMD_HELP_OPT("-i number\t", "line inverted polarity") +BAREBOX_CMD_HELP_END + +BAREBOX_CMD_START(pwm_set) + .cmd = do_pwm_set, + BAREBOX_CMD_DESC("set pwm") + BAREBOX_CMD_OPTS("[-dnDPfp]") + BAREBOX_CMD_GROUP(CMD_GRP_HWMANIP) + BAREBOX_CMD_HELP(cmd_pwm_read_help) +BAREBOX_CMD_END -- 2.35.3 ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [RFC PATCH 1/1] commands: add pwm manipulation command 2023-05-26 8:23 ` [RFC PATCH 1/1] commands: add pwm manipulation command Marc Reilly @ 2023-05-26 9:33 ` Johannes Zink 0 siblings, 0 replies; 3+ messages in thread From: Johannes Zink @ 2023-05-26 9:33 UTC (permalink / raw) To: barebox Hi Marc, thanks for your patch. On 5/26/23 10:23, Marc Reilly wrote: > This introduces a command to set parameters for a pwm device. > > Signed-off-by: Marc Reilly <marc@cpdesign.com.au> > --- > commands/Kconfig | 11 +++++ > commands/Makefile | 1 + > commands/pwm.c | 111 ++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 123 insertions(+) > create mode 100644 commands/pwm.c > > diff --git a/commands/Kconfig b/commands/Kconfig > index 4d3ff631a8..6b7d0bfd79 100644 > --- a/commands/Kconfig > +++ b/commands/Kconfig > @@ -1929,6 +1929,17 @@ config CMD_I2C > -w use word (16 bit) wide access > -v verbose > > + > +config CMD_PWM > + bool > + depends on PWM > + prompt "PWM commands: pwm_set" > + help > + pwm_set - set pwm state > + > + Usage: i2c_set - set pwm parameters this should be pwm_set > + > + > config CMD_LED > bool > depends on LED > diff --git a/commands/Makefile b/commands/Makefile > index 98625a0373..011ae59427 100644 > --- a/commands/Makefile > +++ b/commands/Makefile > @@ -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 > diff --git a/commands/pwm.c b/commands/pwm.c > new file mode 100644 > index 0000000000..8a26430e19 > --- /dev/null > +++ b/commands/pwm.c > @@ -0,0 +1,111 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +// SPDX-FileCopyrightText: © 2023 Marc Reilly <marc@cpdesign.com.au> > + > +/* pwm - pwm commands */ > + > +#include <common.h> > +#include <command.h> > +#include <errno.h> > +#include <malloc.h> > +#include <getopt.h> > +#include <pwm.h> > + > +#define HZ_TO_NANOSECONDS(x) (1000000000UL/(x)) > + > +static int do_pwm_set(int argc, char *argv[]) > +{ > + struct pwm_device *pwm = NULL; > + struct pwm_state state; > + int error = 0; > + char namebuf[128]; > + char *devname = NULL; > + int n = -1, polarity = -1, duty = -1, period = -1, freq = -1, opt; > + > + while ((opt = getopt(argc, argv, "n:d:D:P:f:i:")) > 0) { > + switch (opt) { > + case 'n': > + n = simple_strtol(optarg, NULL, 0); > + break; > + 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': > + freq = simple_strtol(optarg, NULL, 0); > + break; > + case 'i': > + polarity = simple_strtol(optarg, NULL, 0); > + break; > + } > + } > + > + if ((n < 0) && !devname) { > + printf(" need to specify a device\n"); > + return COMMAND_ERROR_USAGE; > + } > + if ((freq < 0) && (duty < 0) && (period < 0)) { > + printf(" need to know some timing info; freq or dury/period\n"); > + return COMMAND_ERROR_USAGE; > + } > + > + if (!devname) { > + sprintf(namebuf, "pwm%d", n); > + } else { > + strcpy(namebuf, devname); > + } > + > + pwm = pwm_request(namebuf); > + if (!pwm) { > + printf("pwm device %s not found\n", namebuf); > + return -ENODEV; > + } > + > + pwm_get_state(pwm, &state); > + if (polarity >= 0) > + state.polarity = polarity; > + > + if (freq > 0) { > + state.p_enable = true; > + state.period_ns = HZ_TO_NANOSECONDS(freq); > + pwm_set_relative_duty_cycle(&state, 50, 100); > + } else if (duty > 0) { > + state.p_enable = true; > + state.period_ns = period; > + state.duty_ns = duty; > + } else { > + state.p_enable = false; This is probably not doing what you expect it to do. To switch off the PWM generation, you need to set state.p_enable = true; state.period_ns = <something_larger_than 0>; state.duty_ns = 0; Please see [1] for more details. Best regards, Johannes [1] https://pengutronix.de/de/blog/2023-03-14-pulse-width-modulation-is-easy-isn-t-it-turning-it-off-and-on-again.html > + } > + > + error = pwm_apply_state(pwm, &state); > + > + pwm_free(pwm); > + > + return error; > +} > + > +BAREBOX_CMD_HELP_START(pwm_read) > +BAREBOX_CMD_HELP_TEXT("Sets a pwm device parameters.") > +BAREBOX_CMD_HELP_TEXT(" Specify the device either by device name or pwm number") > +BAREBOX_CMD_HELP_TEXT(" Timings can either be specified via period + duty (on) duration,") > +BAREBOX_CMD_HELP_TEXT(" or via frequency.") > +BAREBOX_CMD_HELP_TEXT("Options:") > +BAREBOX_CMD_HELP_OPT("-d number\t", "device name (eg 'pwm0')") > +BAREBOX_CMD_HELP_OPT("-n number\t", "pwm chip number (default 0)") > +BAREBOX_CMD_HELP_OPT("-D number\t", "duty cycle (ns)") > +BAREBOX_CMD_HELP_OPT("-P number\t", "period (ns)") > +BAREBOX_CMD_HELP_OPT("-f number\t", "frequency (Hz)") > +BAREBOX_CMD_HELP_OPT("-i number\t", "line inverted polarity") > +BAREBOX_CMD_HELP_END > + > +BAREBOX_CMD_START(pwm_set) > + .cmd = do_pwm_set, > + BAREBOX_CMD_DESC("set pwm") > + BAREBOX_CMD_OPTS("[-dnDPfp]") > + BAREBOX_CMD_GROUP(CMD_GRP_HWMANIP) > + BAREBOX_CMD_HELP(cmd_pwm_read_help) > +BAREBOX_CMD_END -- Pengutronix e.K. | Johannes Zink | Steuerwalder Str. 21 | https://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686| Fax: +49-5121-206917-5555 | ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2023-05-26 9:35 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2023-05-26 8:23 Adding a pwm command Marc Reilly 2023-05-26 8:23 ` [RFC PATCH 1/1] commands: add pwm manipulation command Marc Reilly 2023-05-26 9:33 ` Johannes Zink
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