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@xxxxxxxxxxxxxxx>
---
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@xxxxxxxxxxxxxxx>
+
+/* 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
--
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