pwm: Add generic PWM control host commands

Add generic PWM host commands for setting + getting duty cycle. PWMs can
be controlled through index (board-specific meaning) or by type
(currently KB backlight and display backlight are supported, more can be
added as needed).

BUG=chrome-os-partner:52002
BRANCH=None
TEST=Manual on chell.
`ectool pwmsetduty kb 100` - Verify KB backlight goes to 100%
`ectool pwmgetduty kb` - Prints 100
`ectool pwmgetduty 0` - Prints 100
`ectool pwmsetduty 0 0` - Verify KB backlight goes to 0%
`ectool pwmgetduty kb` - Prints 0
`ectool pwmgetduty disp` - Error res 3 (unsupported PWM type)
`ectool pwmsetduty 1` - Error res 3 (non-existent PWM index)

Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Change-Id: I607c92a291e6c2e3af8238eaf22ad2bb81ffc805
Reviewed-on: https://chromium-review.googlesource.com/344012
Commit-Ready: Shawn N <shawnn@chromium.org>
Tested-by: Shawn N <shawnn@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Reviewed-by: Mary Ruthven <mruthven@chromium.org>

6 files changed, 189 insertions, 3 deletions

diff --git a/board/kevin/board.c b/board/kevin/board.c
index 75bf2b0302..e4a822fee6 100644
--- a/board/kevin/board.c
+++ b/board/kevin/board.c
@@ -72,7 +72,7 @@ const struct pwm_t pwm_channels[] = {
 #ifdef BOARD_KEVIN
 	[PWM_CH_LED_GREEN] = { 0, PWM_CONFIG_DSLEEP, 100 },
 #endif
-	[PWM_CH_BKLIGHT] =   { 2, 0, 10000 },
+	[PWM_CH_DISPLIGHT] = { 2, 0, 10000 },
 	[PWM_CH_LED_RED] =   { 3, PWM_CONFIG_DSLEEP, 100 },
 #ifdef BOARD_KEVIN
 	[PWM_CH_LED_BLUE] =  { 4, PWM_CONFIG_DSLEEP, 100 },
diff --git a/board/kevin/board.h b/board/kevin/board.h
index 7f5e742a86..18c801ec99 100644
--- a/board/kevin/board.h
+++ b/board/kevin/board.h
@@ -14,6 +14,7 @@
 #define CONFIG_HOSTCMD_SPS
 #define CONFIG_POWER_COMMON
 #define CONFIG_PWM
+#define CONFIG_PWM_DISPLIGHT
 #ifdef BOARD_KEVIN
 #define CONFIG_LED_COMMON
 #endif
@@ -132,7 +133,7 @@ enum pwm_channel {
 #ifdef BOARD_KEVIN
 	PWM_CH_LED_GREEN,
 #endif
-	PWM_CH_BKLIGHT,
+	PWM_CH_DISPLIGHT,
 	PWM_CH_LED_RED,
 #ifdef BOARD_KEVIN
 	PWM_CH_LED_BLUE,
diff --git a/common/pwm.c b/common/pwm.c
index 7377d1d170..c689b0acac 100644
--- a/common/pwm.c
+++ b/common/pwm.c
@@ -7,10 +7,78 @@
 #include "console.h"
 #include "gpio.h"
 #include "hooks.h"
+#include "host_command.h"
 #include "pwm.h"
 #include "util.h"
 
 #ifdef CONFIG_PWM
+
+/*
+ * Get target channel based on type / index host command parameters.
+ * Returns 0 if a valid channel is selected, -1 on error.
+ */
+static int get_target_channel(enum pwm_channel *channel, int type, int index)
+{
+	switch (type) {
+	case EC_PWM_TYPE_GENERIC:
+		*channel = index;
+		break;
+#ifdef CONFIG_PWM_KBLIGHT
+	case EC_PWM_TYPE_KB_LIGHT:
+		*channel = PWM_CH_KBLIGHT;
+		break;
+#endif
+#ifdef CONFIG_PWM_DISPLIGHT
+	case EC_PWM_TYPE_DISPLAY_LIGHT:
+		*channel = PWM_CH_DISPLIGHT;
+		break;
+#endif
+	default:
+		return -1;
+	}
+
+	return *channel >= PWM_CH_COUNT;
+}
+
+static int host_command_pwm_set_duty(struct host_cmd_handler_args *args)
+{
+	const struct ec_params_pwm_set_duty *p = args->params;
+	enum pwm_channel channel;
+
+	if (p->percent > 100)
+		return EC_RES_INVALID_PARAM;
+
+	if (get_target_channel(&channel, p->pwm_type, p->index))
+		return EC_RES_INVALID_PARAM;
+
+	pwm_set_duty(channel, p->percent);
+	pwm_enable(channel, p->percent > 0);
+
+	return EC_RES_SUCCESS;
+}
+DECLARE_HOST_COMMAND(EC_CMD_PWM_SET_DUTY,
+		     host_command_pwm_set_duty,
+		     EC_VER_MASK(0));
+
+static int host_command_pwm_get_duty(struct host_cmd_handler_args *args)
+{
+	const struct ec_params_pwm_get_duty *p = args->params;
+	struct ec_response_pwm_get_duty *r = args->response;
+
+	enum pwm_channel channel;
+
+	if (get_target_channel(&channel, p->pwm_type, p->index))
+		return EC_RES_INVALID_PARAM;
+
+	r->percent = pwm_get_duty(channel);
+	args->response_size = sizeof(*r);
+
+	return EC_RES_SUCCESS;
+}
+DECLARE_HOST_COMMAND(EC_CMD_PWM_GET_DUTY,
+		     host_command_pwm_get_duty,
+		     EC_VER_MASK(0));
+
 /**
  * Print status of a PWM channel.
  *
diff --git a/include/config.h b/include/config.h
index 19a51cd194..d80737d677 100644
--- a/include/config.h
+++ b/include/config.h
@@ -1475,6 +1475,9 @@
 #undef CONFIG_PWM_INPUT_LFCLK
 
 /*****************************************************************************/
+/* Support PWM output to display backlight */
+#undef CONFIG_PWM_DISPLIGHT
+
 /* Support PWM output to keyboard backlight */
 #undef CONFIG_PWM_KBLIGHT
 
diff --git a/include/ec_commands.h b/include/ec_commands.h
index a205878bec..faeeb412fb 100644
--- a/include/ec_commands.h
+++ b/include/ec_commands.h
@@ -1173,6 +1173,7 @@ struct ec_params_pwm_set_fan_target_rpm_v1 {
 } __packed;
 
 /* Get keyboard backlight */
+/* OBSOLETE - Use EC_CMD_PWM_SET_DUTY */
 #define EC_CMD_PWM_GET_KEYBOARD_BACKLIGHT 0x22
 
 struct ec_response_pwm_get_keyboard_backlight {
@@ -1181,6 +1182,7 @@ struct ec_response_pwm_get_keyboard_backlight {
 } __packed;
 
 /* Set keyboard backlight */
+/* OBSOLETE - Use EC_CMD_PWM_SET_DUTY */
 #define EC_CMD_PWM_SET_KEYBOARD_BACKLIGHT 0x23
 
 struct ec_params_pwm_set_keyboard_backlight {
@@ -1201,6 +1203,35 @@ struct ec_params_pwm_set_fan_duty_v1 {
 	uint8_t fan_idx;
 } __packed;
 
+#define EC_CMD_PWM_SET_DUTY 0x25
+
+enum ec_pwm_type {
+	/* All types, indexed by board-specific enum pwm_channel */
+	EC_PWM_TYPE_GENERIC = 0,
+	/* Keyboard backlight */
+	EC_PWM_TYPE_KB_LIGHT,
+	/* Display backlight */
+	EC_PWM_TYPE_DISPLAY_LIGHT,
+	EC_PWM_TYPE_COUNT,
+};
+
+struct ec_params_pwm_set_duty {
+	uint8_t percent;   /* Duty cycle percent on [0, 100] */
+	uint8_t pwm_type;  /* ec_pwm_type */
+	uint8_t index;     /* Type-specific index, or 0 if unique */
+} __packed;
+
+#define EC_CMD_PWM_GET_DUTY 0x26
+
+struct ec_params_pwm_get_duty {
+	uint8_t pwm_type;  /* ec_pwm_type */
+	uint8_t index;     /* Type-specific index, or 0 if unique */
+} __packed;
+
+struct ec_response_pwm_get_duty {
+	uint8_t percent;
+} __packed;
+
 /*****************************************************************************/
 /*
  * Lightbar commands. This looks worse than it is. Since we only use one HOST
diff --git a/util/ectool.c b/util/ectool.c
index 59793e21d6..0e3c1ee596 100644
--- a/util/ectool.c
+++ b/util/ectool.c
@@ -173,10 +173,14 @@ const char help_str[] =
 	"      Prints current keyboard backlight percent\n"
 	"  pwmgetnumfans\n"
 	"      Prints the number of fans present\n"
+	"  pwmgetduty\n"
+	"      Prints the current duty cycle for given PWM\n"
 	"  pwmsetfanrpm <targetrpm>\n"
 	"      Set target fan RPM\n"
 	"  pwmsetkblight <percent>\n"
 	"      Set keyboard backlight in percent\n"
+	"  pwmsetduty\n"
+	"      Set duty cycle of given PWM in percent\n"
 	"  readtest <patternoffset> <size>\n"
 	"      Reads a pattern from the EC via LPC\n"
 	"  reboot_ec <RO|RW|cold|hibernate|disable-jump> [at-shutdown]\n"
@@ -1858,7 +1862,6 @@ int cmd_pwm_set_fan_rpm(int argc, char *argv[])
 	return 0;
 }
 
-
 int cmd_pwm_get_keyboard_backlight(int argc, char *argv[])
 {
 	struct ec_response_pwm_get_keyboard_backlight r;
@@ -1903,6 +1906,84 @@ int cmd_pwm_set_keyboard_backlight(int argc, char *argv[])
 	return 0;
 }
 
+int cmd_pwm_get_duty(int argc, char *argv[])
+{
+	struct ec_params_pwm_get_duty p;
+	struct ec_response_pwm_get_duty r;
+	char *e;
+	int rv;
+
+	if (argc != 2) {
+		fprintf(stderr, "Usage: %s <pwm_idx> | kb | disp\n", argv[0]);
+		return -1;
+	}
+
+	if (!strcmp(argv[1], "kb")) {
+		p.pwm_type = EC_PWM_TYPE_KB_LIGHT;
+		p.index = 0;
+	} else if (!strcmp(argv[1], "disp")) {
+		p.pwm_type = EC_PWM_TYPE_DISPLAY_LIGHT;
+		p.index = 0;
+	} else {
+		p.pwm_type = EC_PWM_TYPE_GENERIC;
+		p.index = strtol(argv[1], &e, 0);
+		if (e && *e) {
+			fprintf(stderr, "Bad pwm_idx\n");
+			return -1;
+		}
+	}
+
+	rv = ec_command(EC_CMD_PWM_GET_DUTY, 0, &p, sizeof(p), &r, sizeof(r));
+	if (rv < 0)
+		return rv;
+
+	printf("Current PWM duty: %d\n", r.percent);
+	return 0;
+}
+
+
+int cmd_pwm_set_duty(int argc, char *argv[])
+{
+	struct ec_params_pwm_set_duty p;
+	char *e;
+	int rv;
+
+	if (argc != 3) {
+		fprintf(stderr, "Usage: %s <pwm_idx> | kb | disp <percent>\n",
+			argv[0]);
+		return -1;
+	}
+
+	if (!strcmp(argv[1], "kb")) {
+		p.pwm_type = EC_PWM_TYPE_KB_LIGHT;
+		p.index = 0;
+	} else if (!strcmp(argv[1], "disp")) {
+		p.pwm_type = EC_PWM_TYPE_DISPLAY_LIGHT;
+		p.index = 0;
+	} else {
+		p.pwm_type = EC_PWM_TYPE_GENERIC;
+		p.index = strtol(argv[1], &e, 0);
+		if (e && *e) {
+			fprintf(stderr, "Bad pwm_idx\n");
+			return -1;
+		}
+	}
+
+	p.percent = strtol(argv[2], &e, 0);
+	if (e && *e) {
+		fprintf(stderr, "Bad percent.\n");
+		return -1;
+	}
+
+	rv = ec_command(EC_CMD_PWM_SET_DUTY, 0,
+			&p, sizeof(p), NULL, 0);
+	if (rv < 0)
+		return rv;
+
+	printf("PWM set.\n");
+	return 0;
+}
+
 int cmd_fanduty(int argc, char *argv[])
 {
 	struct ec_params_pwm_set_fan_duty_v1 p_v1;
@@ -6602,8 +6683,10 @@ const struct command commands[] = {
 	{"pwmgetfanrpm", cmd_pwm_get_fan_rpm},
 	{"pwmgetkblight", cmd_pwm_get_keyboard_backlight},
 	{"pwmgetnumfans", cmd_pwm_get_num_fans},
+	{"pwmgetduty", cmd_pwm_get_duty},
 	{"pwmsetfanrpm", cmd_pwm_set_fan_rpm},
 	{"pwmsetkblight", cmd_pwm_set_keyboard_backlight},
+	{"pwmsetduty", cmd_pwm_set_duty},
 	{"readtest", cmd_read_test},
 	{"reboot_ec", cmd_reboot_ec},
 	{"rtcget", cmd_rtc_get},