* [PATCH v4 1/2] commands: add pwm manipulation command
2023-06-02 4:53 Adding PWM Commands (v4) Marc Reilly
@ 2023-06-02 4:53 ` Marc Reilly
2023-06-06 9:07 ` Sascha Hauer
2023-06-02 4:53 ` [PATCH v4 2/2] include: pwm: minor function doc fix for pwm_set_relative_duty_cycle() Marc Reilly
1 sibling, 1 reply; 4+ messages in thread
From: Marc Reilly @ 2023-06-02 4:53 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 | 12 +++
commands/Makefile | 1 +
commands/pwm.c | 199 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 212 insertions(+)
create mode 100644 commands/pwm.c
diff --git a/commands/Kconfig b/commands/Kconfig
index 4d3ff631a8..28f9e46a59 100644
--- a/commands/Kconfig
+++ b/commands/Kconfig
@@ -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
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..82535d229e
--- /dev/null
+++ b/commands/pwm.c
@@ -0,0 +1,199 @@
+// 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))
+#define HZ_FROM_NANOSECONDS(x) (1000000000UL/(x))
+
+static bool is_equal_state(struct pwm_state *state1, struct pwm_state *state2)
+{
+ return (state1->period_ns == state2->period_ns)
+ && (state1->duty_ns == state2->duty_ns)
+ && (state1->polarity == state2->polarity)
+ && (state1->p_enable == state2->p_enable);
+}
+
+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);
+ break;
+ case 'i':
+ invert_polarity = true;
+ break;
+ case 's':
+ stop = true;
+ break;
+ case 'v':
+ verbose = true;
+ 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;
+ }
+ 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;
+ }
+
+ 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));
+
+ pwm_free(pwm);
+ return 0;
+ }
+
+ if ((state.period_ns == 0) && (freq < 0) && (period < 0)) {
+ printf(" need to know some timing info: freq or period\n");
+ pwm_free(pwm);
+ return COMMAND_ERROR_USAGE;
+ }
+
+ orig_state = state;
+
+ if (invert_polarity)
+ state.polarity = invert_polarity;
+
+ /* period */
+ if (freq > 0) {
+ state.p_enable = true;
+ state.period_ns = HZ_TO_NANOSECONDS(freq);
+ if (use_default_width && (width < 0)) {
+ width = 50;
+ }
+ } 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) {
+ state.duty_ns = duty;
+ }
+
+ if (state.duty_ns > state.period_ns) {
+ printf(" duty_ns must not be greater than period_ns\n");
+ }
+
+ /* only set the state if its changed */
+ if (!is_equal_state(&orig_state, & state))
+ error = pwm_apply_state(pwm, &state);
+
+ if (error < 0)
+ printf(" error while applying state: %d\n", error);
+
+ /* stop handled as an additional step on purpose, allows turning off
+ * output (eg if duty => 0) and stopping in one command
+ */
+ if (stop > 0) {
+ state.p_enable = false;
+ error = pwm_apply_state(pwm, &state);
+ if (error < 0)
+ printf(" error while stopping: %d\n", error);
+ }
+
+ pwm_free(pwm);
+
+ return error;
+}
+
+BAREBOX_CMD_HELP_START(pwm)
+BAREBOX_CMD_HELP_TEXT("Sets pwm device parameters, or shows current value.")
+BAREBOX_CMD_HELP_TEXT(" Specify the pwm device by device name.")
+BAREBOX_CMD_HELP_TEXT(" If no other parameters are given, or if args has '-v',")
+BAREBOX_CMD_HELP_TEXT(" then show the current values only.")
+BAREBOX_CMD_HELP_TEXT(" Timings can either be specified via period + duty (on) duration,")
+BAREBOX_CMD_HELP_TEXT(" or via frequency. Duty can be given either as a percentage or time.")
+BAREBOX_CMD_HELP_TEXT(" If a parameter is not specified, the current value will be used")
+BAREBOX_CMD_HELP_TEXT(" where possible.")
+BAREBOX_CMD_HELP_TEXT(" To set an output to inactive state, set the duty to 0.")
+BAREBOX_CMD_HELP_TEXT(" (although note this will not by itself stop the pwm running.)")
+BAREBOX_CMD_HELP_TEXT(" Stopping the pwm device does not necessarily set the output to inactive,")
+BAREBOX_CMD_HELP_TEXT(" but stop is handled last, so can be done in addition to other changes.")
+BAREBOX_CMD_HELP_TEXT("Options:")
+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")
+BAREBOX_CMD_HELP_OPT("-i\t", "line inverted polarity")
+BAREBOX_CMD_HELP_OPT("-s\t", "stop (disable) the pwm device")
+BAREBOX_CMD_HELP_OPT("-v\t", "print current values")
+BAREBOX_CMD_HELP_END
+
+BAREBOX_CMD_START(pwm)
+ .cmd = do_pwm_cmd,
+ BAREBOX_CMD_DESC("pwm")
+ BAREBOX_CMD_OPTS("[-dDPfwisv]")
+ BAREBOX_CMD_GROUP(CMD_GRP_HWMANIP)
+ BAREBOX_CMD_HELP(cmd_pwm_help)
+BAREBOX_CMD_END
--
2.35.3
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