On Mon, May 29, 2023 at 09:06:25PM +1000, Marc Reilly wrote:
> This introduces a command to set parameters for a pwm device.
>
> Signed-off-by: Marc Reilly <[email protected]>
> ---
> commands/Kconfig | 11 ++++
> commands/Makefile | 1 +
> commands/pwm.c | 143 ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 155 insertions(+)
> create mode 100644 commands/pwm.c
>
> diff --git a/commands/Kconfig b/commands/Kconfig
> index 4d3ff631a8..cc7585bbb2 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: pwm_set [dDPfwis]
> +
> + Controls the pwm values such as period and duty cycle
> +
> 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..94bbbaf1be
> --- /dev/null
> +++ b/commands/pwm.c
> @@ -0,0 +1,143 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +// SPDX-FileCopyrightText: © 2023 Marc Reilly <[email protected]>
> +
> +/* 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 *devname = NULL;
> + int duty = -1, period = -1;
> + int freq = -1, width = -1;
> + int invert_polarity = -1, stop = -1;
better bool invert_polarity = false, stop = false.
> + int opt;
> +
> + while ((opt = getopt(argc, argv, "d:D:P:f:w:is")) > 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':
> + freq = simple_strtol(optarg, NULL, 0);
> + break;
> + case 'w':
> + width = simple_strtol(optarg, NULL, 0);
> + break;
> + case 'i':
> + invert_polarity = 1;
> + break;
> + case 's':
> + stop = 1;
> + break;
> + }
> + }
> +
> + 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;
> + }
You should also check if both freq and period are given:
if (freq >= 0 && period >= 0)
printf("Specify period or frequency, not both\n");
likewise width and duty:
if (width >= 0 && duty >= 0)
printf("Specify width or duty cycle, not both\n");
> + 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;
> + }
> +
> + pwm_get_state(pwm, &state);
> +
> + if ((state.period_ns == 0)
> + && (freq < 0) && (duty < 0) && (period < 0)) {
It's already an error when:
state.period_ns == 0 && freq < 0 && period < 0
No need to check for duty here.
> + printf(" need to know some timing info; freq or duty/period\n");
> + pwm_free(pwm);
> + return COMMAND_ERROR_USAGE;
> + }
Maybe just print the current PWM state when no actions are given?
> +
> + if (invert_polarity >= 0)
> + state.polarity = invert_polarity;
> +
> + /* period */
> + if (freq > 0) {
> + state.p_enable = true;
> + state.period_ns = HZ_TO_NANOSECONDS(freq);
> + if (width < 0) {
> + width = 50;
> + }
I think this shouldn't be here, at least I don't see why it shouldn't be
possible to configure a PWM with -f x -D y.
> + } else if (period > 0) {
> + state.p_enable = true;
> + state.period_ns = period;
> + }
> +
> + /* duty */
> + if (width >= 0) {
> + pwm_set_relative_duty_cycle(&state, width, 100);
> + } else if (duty >= 0) {
> + if (duty > state.period_ns)
> + printf(" warning: duty_ns is greater than period\n");
> +
> + state.duty_ns = duty;
> + }
> +
> + error = pwm_apply_state(pwm, &state);
> +
> + if (stop > 0) {
> + state.p_enable = false;
> + error = pwm_apply_state(pwm, &state);
> + }
No need to call pwm_apply_state() twice when the PWM shall be stopped.
This should do it:
if (stop > 0)
state.p_enable = false;
error = pwm_apply_state(pwm, &state);
Sascha
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
