Adding PWM commands

Adding PWM commands

[Marc Reilly]

Thanks again all for comments so far.

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 v3 1/3] commands: add pwm manipulation command

[Marc Reilly]

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    | 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 <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 *devname = NULL;
+	int duty = -1, period = -1;
+	int freq = -1, width = -1;
+	int invert_polarity = -1, stop = -1;
+	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;
+	}
+	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)) {
+		printf(" need to know some timing info; freq or duty/period\n");
+		pwm_free(pwm);
+		return COMMAND_ERROR_USAGE;
+	}
+
+	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;
+		}
+	} 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);
+	}
+
+	pwm_free(pwm);
+
+	return error;
+}
+
+BAREBOX_CMD_HELP_START(pwm_set)
+BAREBOX_CMD_HELP_TEXT("Sets a pwm device parameters.")
+BAREBOX_CMD_HELP_TEXT(" Specify the device by device name")
+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 - except when setting frequency, in which case")
+BAREBOX_CMD_HELP_TEXT("  the 'width' will default to 50%.")
+BAREBOX_CMD_HELP_TEXT(" Stopping the device does not necessarily set the output to inactive.")
+BAREBOX_CMD_HELP_TEXT(" To set an output to inactive state, set the duty to 0.")
+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_END
+
+BAREBOX_CMD_START(pwm_set)
+	.cmd		= do_pwm_set,
+	BAREBOX_CMD_DESC("set pwm")
+	BAREBOX_CMD_OPTS("[-dDPfwis]")
+	BAREBOX_CMD_GROUP(CMD_GRP_HWMANIP)
+	BAREBOX_CMD_HELP(cmd_pwm_set_help)
+BAREBOX_CMD_END
-- 
2.35.3

Re: [PATCH v3 1/3] commands: add pwm manipulation command

[Sascha Hauer]

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 <marc@cpdesign.com.au>
> ---
>  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 <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 *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 |

[PATCH v3 2/3] commands: pwm: add pwm_get command

[Marc Reilly]

Signed-off-by: Marc Reilly <marc@cpdesign.com.au>
---
 commands/Kconfig |  7 ++++++
 commands/pwm.c   | 56 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+)

diff --git a/commands/Kconfig b/commands/Kconfig
index cc7585bbb2..f2a6d22f69 100644
--- a/commands/Kconfig
+++ b/commands/Kconfig
@@ -1940,6 +1940,13 @@ config CMD_PWM
 
 	  Controls the pwm values such as period and duty cycle
 
+
+	  pwm_get - get pwm state
+
+	  Usage: pwm_get [d]
+
+	  Displays the pwm values such as period and duty cycle
+
 config CMD_LED
 	bool
 	depends on LED
diff --git a/commands/pwm.c b/commands/pwm.c
index 94bbbaf1be..18f65b0a59 100644
--- a/commands/pwm.c
+++ b/commands/pwm.c
@@ -141,3 +141,59 @@ BAREBOX_CMD_START(pwm_set)
 	BAREBOX_CMD_GROUP(CMD_GRP_HWMANIP)
 	BAREBOX_CMD_HELP(cmd_pwm_set_help)
 BAREBOX_CMD_END
+
+#define HZ_FROM_NANOSECONDS(x) (1000000000UL/(x))
+
+static int do_pwm_get(int argc, char *argv[])
+{
+	struct pwm_device *pwm = NULL;
+	struct pwm_state state;
+	char *devname = NULL;
+	int opt;
+
+	while ((opt = getopt(argc, argv, "d:")) > 0) {
+		switch (opt) {
+		case 'd':
+			devname = optarg;
+			break;
+		}
+	}
+
+	if (!devname) {
+		printf(" need to specify a device\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);
+
+	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;
+}
+
+BAREBOX_CMD_HELP_START(pwm_get)
+BAREBOX_CMD_HELP_TEXT("Gets a pwm device parameters.")
+BAREBOX_CMD_HELP_TEXT(" Specify the device by device name")
+BAREBOX_CMD_HELP_TEXT("Options:")
+BAREBOX_CMD_HELP_OPT("-d string", "device name (eg 'pwm0')")
+BAREBOX_CMD_HELP_END
+
+BAREBOX_CMD_START(pwm_get)
+	.cmd		= do_pwm_get,
+	BAREBOX_CMD_DESC("get pwm")
+	BAREBOX_CMD_OPTS("[-d]")
+	BAREBOX_CMD_GROUP(CMD_GRP_HWMANIP)
+	BAREBOX_CMD_HELP(cmd_pwm_get_help)
+BAREBOX_CMD_END
-- 
2.35.3

Re: [PATCH v3 2/3] commands: pwm: add pwm_get command

[Sascha Hauer]

On Mon, May 29, 2023 at 09:06:26PM +1000, Marc Reilly wrote:
> Signed-off-by: Marc Reilly <marc@cpdesign.com.au>
> ---
>  commands/Kconfig |  7 ++++++
>  commands/pwm.c   | 56 ++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 63 insertions(+)
> 
> diff --git a/commands/Kconfig b/commands/Kconfig
> index cc7585bbb2..f2a6d22f69 100644
> --- a/commands/Kconfig
> +++ b/commands/Kconfig
> @@ -1940,6 +1940,13 @@ config CMD_PWM
>  
>  	  Controls the pwm values such as period and duty cycle
>  
> +
> +	  pwm_get - get pwm state
> +
> +	  Usage: pwm_get [d]
> +
> +	  Displays the pwm values such as period and duty cycle
> +
>  config CMD_LED
>  	bool
>  	depends on LED
> diff --git a/commands/pwm.c b/commands/pwm.c
> index 94bbbaf1be..18f65b0a59 100644
> --- a/commands/pwm.c
> +++ b/commands/pwm.c
> @@ -141,3 +141,59 @@ BAREBOX_CMD_START(pwm_set)
>  	BAREBOX_CMD_GROUP(CMD_GRP_HWMANIP)
>  	BAREBOX_CMD_HELP(cmd_pwm_set_help)
>  BAREBOX_CMD_END
> +
> +#define HZ_FROM_NANOSECONDS(x) (1000000000UL/(x))
> +
> +static int do_pwm_get(int argc, char *argv[])
> +{
> +	struct pwm_device *pwm = NULL;
> +	struct pwm_state state;
> +	char *devname = NULL;
> +	int opt;
> +
> +	while ((opt = getopt(argc, argv, "d:")) > 0) {
> +		switch (opt) {
> +		case 'd':
> +			devname = optarg;
> +			break;
> +		}
> +	}
> +
> +	if (!devname) {
> +		printf(" need to specify a device\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);
> +
> +	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));

Not sure if this deserves an extra command. You could print the
information along with the pwm_set command when no action is given
or when an additional -v (for verbose) is given.

When doint this the command could simply be named 'pwm' instead of
'pwm_set'

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 |

[PATCH v3 3/3] include: pwm: minor function doc fix for pwm_set_relative_duty_cycle()

[Marc Reilly]

Signed-off-by: Marc Reilly <marc@cpdesign.com.au>
---
 include/pwm.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/pwm.h b/include/pwm.h
index 643ef4d7ee..02af7d0a5f 100644
--- a/include/pwm.h
+++ b/include/pwm.h
@@ -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:
  *
-- 
2.35.3

Adding PWM Commands

[Marc Reilly]

Hi,

Thanks all for comments so far.

Changes in v2:
- remove '-n' option to specify device by number
- fix freeing resources on all return paths
- add pwm_get command

Cheers
Marc