common: pwm: handle EC_PWM_TYPE_KB_LIGHT with the kblight API

Change the PWM host command handling of EC_PWM_TYPE_KB_LIGHT to use the
kblight APIs directly rather than the PWM ones. This makes the host
command work correctly with kblight drivers that do not use the ECOS PWM
APIs.

Tested snippet:

  localhost /home/chronos/user # ectool pwmgetkblight
  Keyboard backlight disabled.
  localhost /home/chronos/user # ectool pwmgetduty kb
  Current PWM duty: 0

  <change the backlight on the device>

  localhost /home/chronos/user # ectool pwmgetkblight
  Current keyboard backlight percent: 40
  localhost /home/chronos/user # ectool pwmgetduty kb
  Current PWM duty: 26214

  localhost /home/chronos/user # ectool pwmsetkblight 50
  Keyboard backlight set.
  localhost /home/chronos/user # ectool pwmgetduty kb
  Current PWM duty: 32767

  localhost /home/chronos/user # ectool pwmsetduty kb 65535
  PWM set.
  localhost /home/chronos/user # ectool pwmgetkblight
  Current keyboard backlight percent: 100

BRANCH=none
BUG=b:217741090
TEST=ectool kblight and pwm commands
TEST=make runhosttests -j8
TEST=zmake testall

Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>
Change-Id: Ib73f321334ff63cd8c512d0985c3504133834ec4
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3468504
Reviewed-by: Aaron Massey <aaronmassey@google.com>

1 files changed, 23 insertions, 7 deletions

diff --git a/common/pwm.c b/common/pwm.c
index 41989a94e0..858057946b 100644
--- a/common/pwm.c
+++ b/common/pwm.c
@@ -8,6 +8,7 @@
 #include "gpio.h"
 #include "hooks.h"
 #include "host_command.h"
+#include "keyboard_backlight.h"
 #include "pwm.h"
 #include "util.h"
 
@@ -17,6 +18,10 @@
 
 #ifdef CONFIG_PWM
 
+#define PWM_RAW_TO_PERCENT(v) \
+	DIV_ROUND_NEAREST((uint32_t)(v) * 100, UINT16_MAX)
+#define PWM_PERCENT_TO_RAW(v) ((uint32_t)(v) * UINT16_MAX / 100)
+
 /*
  * Get target channel based on type / index host command parameters.
  * Returns 0 if a valid channel is selected, -1 on error.
@@ -27,11 +32,6 @@ static int get_target_channel(enum pwm_channel *channel, int type, int index)
 	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;
@@ -49,13 +49,13 @@ __attribute__((weak)) void pwm_set_raw_duty(enum pwm_channel ch, uint16_t duty)
 	int percent;
 
 	/* Convert 16 bit duty to percent on [0, 100] */
-	percent = DIV_ROUND_NEAREST((uint32_t)duty * 100, 65535);
+	percent = PWM_RAW_TO_PERCENT(duty);
 	pwm_set_duty(ch, percent);
 }
 
 __attribute__((weak)) uint16_t pwm_get_raw_duty(enum pwm_channel ch)
 {
-	return (pwm_get_duty(ch) * 65535) / 100;
+	return PWM_PERCENT_TO_RAW(pwm_get_duty(ch));
 }
 
 static enum ec_status
@@ -64,6 +64,14 @@ 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;
 
+#ifdef CONFIG_PWM_KBLIGHT
+	if (p->pwm_type == EC_PWM_TYPE_KB_LIGHT) {
+		kblight_set(PWM_RAW_TO_PERCENT(p->duty));
+		kblight_enable(p->duty > 0);
+		return EC_RES_SUCCESS;
+	}
+#endif
+
 	if (get_target_channel(&channel, p->pwm_type, p->index))
 		return EC_RES_INVALID_PARAM;
 
@@ -84,6 +92,14 @@ host_command_pwm_get_duty(struct host_cmd_handler_args *args)
 
 	enum pwm_channel channel;
 
+#ifdef CONFIG_PWM_KBLIGHT
+	if (p->pwm_type == EC_PWM_TYPE_KB_LIGHT) {
+		r->duty = PWM_PERCENT_TO_RAW(kblight_get());
+		args->response_size = sizeof(*r);
+		return EC_RES_SUCCESS;
+	}
+#endif
+
 	if (get_target_channel(&channel, p->pwm_type, p->index))
 		return EC_RES_INVALID_PARAM;