volteer: Support LEDs

Enable support for PWM LED control, define PWM channels and LED colors,
and implement interface for setting LED color. Meaningful LED output
is based on data from the charger, which isn't configured yet. In the
meantime, stub out the parts of the charger implementation required to
build LED code.

BUG=b:139554899
BRANCH=none
TEST=make buildall

Change-Id: I983777320da4c1f8a181cffb0f7541af4c41a410
Signed-off-by: Abe Levkoy <alevkoy@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1832887
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>

4 files changed, 135 insertions, 0 deletions

diff --git a/baseboard/volteer/baseboard.c b/baseboard/volteer/baseboard.c
index 4f589a2c8b..be0370074f 100644
--- a/baseboard/volteer/baseboard.c
+++ b/baseboard/volteer/baseboard.c
@@ -4,8 +4,13 @@
  */
 
 /* Volteer family-specific configuration */
+#include "baseboard.h"
+#include "battery.h"
+#include "charge_state.h"
 #include "gpio.h"
 #include "i2c.h"
+#include "pwm.h"
+#include "pwm_chip.h"
 
 /******************************************************************************/
 /* Wake up pins */
@@ -66,3 +71,43 @@ const struct i2c_port_t i2c_ports[] = {
 	},
 };
 const unsigned int i2c_ports_used = ARRAY_SIZE(i2c_ports);
+
+const struct pwm_t pwm_channels[] = {
+	[PWM_CH_LED1_BLUE] = {
+		.channel = 2,
+		.flags = PWM_CONFIG_ACTIVE_LOW | PWM_CONFIG_DSLEEP,
+		.freq = 100,
+	},
+	[PWM_CH_LED2_GREEN] = {
+		.channel = 0,
+		.flags = PWM_CONFIG_ACTIVE_LOW | PWM_CONFIG_DSLEEP,
+		.freq = 100,
+	},
+	[PWM_CH_LED3_RED] = {
+		.channel = 1,
+		.flags = PWM_CONFIG_ACTIVE_LOW | PWM_CONFIG_DSLEEP,
+		.freq = 100,
+	},
+};
+BUILD_ASSERT(ARRAY_SIZE(pwm_channels) == PWM_CH_COUNT);
+
+/* Stub out battery and charging functions to compile common LED code.
+ * TODO(b/140557020): Define these for real.
+ */
+#ifdef CONFIG_CHARGER
+#error "Write real definitions for charger and battery functions."
+#endif
+enum charge_state charge_get_state(void)
+{
+	return PWR_STATE_UNCHANGE;
+}
+
+enum battery_present battery_is_present(void)
+{
+	return BP_NOT_SURE;
+}
+
+int charge_get_percent(void)
+{
+	return 0;
+}
diff --git a/baseboard/volteer/baseboard.h b/baseboard/volteer/baseboard.h
index f7a6f6793c..e2ebea1c21 100644
--- a/baseboard/volteer/baseboard.h
+++ b/baseboard/volteer/baseboard.h
@@ -22,6 +22,16 @@
 #define CONFIG_CRC8
 #define CONFIG_CROS_BOARD_INFO
 #define CONFIG_HIBERNATE_PSL
+#define CONFIG_LED_COMMON
+/* TODO(b/140557020): Define CONFIG_LED_ONOFF_STATES and
+ * CONFIG_LED_ONOFF_STATES_BAT_LOW when CONFIG_CHARGER is defined.
+ */
+#define CONFIG_LED_PWM
+/* TODO(b/140557020): Remove this when CONFIG_CHARGER is defined. */
+#define CONFIG_LED_PWM_CHARGE_STATE_ONLY
+/* Although there are 2 LEDs, they are both controlled by the same lines. */
+#define CONFIG_LED_PWM_COUNT 1
+#define CONFIG_PWM
 #define CONFIG_VBOOT_HASH
 #define CONFIG_VSTORE
 #define CONFIG_VSTORE_SLOT_COUNT 1
@@ -68,6 +78,13 @@
 
 #ifndef __ASSEMBLER__
 
+enum pwm_channel {
+	PWM_CH_LED1_BLUE = 0,
+	PWM_CH_LED2_GREEN,
+	PWM_CH_LED3_RED,
+	PWM_CH_COUNT
+};
+
 #endif /* !__ASSEMBLER__ */
 
 #endif /* __CROS_EC_BASEBOARD_H */
diff --git a/baseboard/volteer/build.mk b/baseboard/volteer/build.mk
index 03a91ceda7..bb7e57ad6a 100644
--- a/baseboard/volteer/build.mk
+++ b/baseboard/volteer/build.mk
@@ -7,3 +7,4 @@
 #
 
 baseboard-y=baseboard.o
+baseboard-y+=led.o
diff --git a/baseboard/volteer/led.c b/baseboard/volteer/led.c
new file mode 100644
index 0000000000..f063956a4c
--- /dev/null
+++ b/baseboard/volteer/led.c
@@ -0,0 +1,72 @@
+/* Copyright 2019 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Power and battery LED control for Volteer
+ */
+
+#include "common.h"
+#include "ec_commands.h"
+#include "led_common.h"
+#include "led_pwm.h"
+
+const enum ec_led_id supported_led_ids[] = {
+	EC_LED_ID_BATTERY_LED,
+};
+const int supported_led_ids_count = ARRAY_SIZE(supported_led_ids);
+
+struct pwm_led led_color_map[] = {
+				/* Red, Green, Blue */
+	[EC_LED_COLOR_RED] =    {  100,   0,     0 },
+	[EC_LED_COLOR_GREEN] =  {    0, 100,     0 },
+	[EC_LED_COLOR_BLUE] =   {    0,   0,   100 },
+	[EC_LED_COLOR_YELLOW] = {  100, 100,     0 },
+	[EC_LED_COLOR_WHITE] =  {  100, 100,   100 },
+	[EC_LED_COLOR_AMBER] =  {  100,  75,     0 },
+};
+
+struct pwm_led pwm_leds[] = {
+	/* 2 RGB diffusers controlled by 1 set of 3 channels. */
+	[PWM_LED0] = {
+		PWM_CH_LED3_RED,
+		PWM_CH_LED2_GREEN,
+		PWM_CH_LED1_BLUE,
+	},
+};
+
+void led_get_brightness_range(enum ec_led_id led_id, uint8_t *brightness_range)
+{
+	/* TODO(b/139554899): Consider letting these go up to 255. */
+	brightness_range[EC_LED_COLOR_RED] = 100;
+	brightness_range[EC_LED_COLOR_GREEN] = 100;
+	brightness_range[EC_LED_COLOR_BLUE] = 100;
+}
+
+int led_set_brightness(enum ec_led_id led_id, const uint8_t *brightness)
+{
+	enum pwm_led_id pwm_id;
+
+	/* Convert ec_led_id to pwm_led_id. */
+	if (led_id == EC_LED_ID_BATTERY_LED)
+		pwm_id = PWM_LED0;
+	else
+		return EC_ERROR_UNKNOWN;
+
+	if (brightness[EC_LED_COLOR_RED])
+		set_pwm_led_color(pwm_id, EC_LED_COLOR_RED);
+	else if (brightness[EC_LED_COLOR_GREEN])
+		set_pwm_led_color(pwm_id, EC_LED_COLOR_GREEN);
+	else if (brightness[EC_LED_COLOR_BLUE])
+		set_pwm_led_color(pwm_id, EC_LED_COLOR_BLUE);
+	else if (brightness[EC_LED_COLOR_YELLOW])
+		set_pwm_led_color(pwm_id, EC_LED_COLOR_YELLOW);
+	else if (brightness[EC_LED_COLOR_WHITE])
+		set_pwm_led_color(pwm_id, EC_LED_COLOR_WHITE);
+	else if (brightness[EC_LED_COLOR_AMBER])
+		set_pwm_led_color(pwm_id, EC_LED_COLOR_AMBER);
+	else
+		/* Otherwise, the "color" is "off". */
+		set_pwm_led_color(pwm_id, -1);
+
+	return EC_SUCCESS;
+}