Clean up ADC module

ADC config structs are now chip-specific; this saves code size
(several hundred bytes on LM4, since no need for 24-entry ADC channel
to GPIO mapping table).

BUG=chrome-os-partner:15579
BRANCH=none
TEST='adc' with system on and off; ChargerCurrent should be bigger when on.

Change-Id: Ia88b3f043438bec049f2d2ad39fc42dcf86d9424
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/36798

7 files changed, 96 insertions, 104 deletions

diff --git a/board/bds/board.c b/board/bds/board.c
index 04e3d56c67..ccbe69b38c 100644
--- a/board/bds/board.c
+++ b/board/bds/board.c
@@ -19,7 +19,7 @@ const struct adc_t adc_channels[ADC_CH_COUNT] = {
 	 * = -225 * ADC_VALUE / ADC_READ_MAX + 420.5
 	 */
 	{"ECTemp", LM4_ADC_SEQ0, -225, ADC_READ_MAX, 420,
-	 LM4_AIN_NONE, 0x0e /* TS0 | IE0 | END0 */},
+	 LM4_AIN_NONE, 0x0e /* TS0 | IE0 | END0 */, 0, 0},
 
 	/* Charger current is mapped from 0~4000mA to 0~1.6V.
 	 * And ADC maps 0~3.3V to ADC_READ_MAX.
@@ -28,7 +28,7 @@ const struct adc_t adc_channels[ADC_CH_COUNT] = {
 	 * board, but that's good enough for debugging the ADC.
 	 */
 	{"BDSPot", LM4_ADC_SEQ1, 33 * 4000, ADC_READ_MAX * 16, 0,
-	 LM4_AIN(0), 0x06 /* IE0 | END0 */},
+	 LM4_AIN(0), 0x06 /* IE0 | END0 */, LM4_GPIO_E, (1<<3)},
 };
 
 
diff --git a/board/link/board.c b/board/link/board.c
index 5f7fbf1106..e4fbb53423 100644
--- a/board/link/board.c
+++ b/board/link/board.c
@@ -5,8 +5,7 @@
 /* EC for Link board configuration */
 
 #include "adc.h"
-#include "board.h"
-#include "config.h"
+#include "common.h"
 #include "gpio.h"
 #include "i2c.h"
 #include "lm4_adc.h"
@@ -22,7 +21,6 @@
 #define power_button_interrupt NULL
 #endif
 
-
 /* GPIO signal list.  Must match order from enum gpio_signal. */
 const struct gpio_info gpio_list[GPIO_COUNT] = {
 	/* Inputs with interrupt handlers are first for efficiency */
@@ -126,13 +124,13 @@ const struct adc_t adc_channels[ADC_CH_COUNT] = {
 	 * = -225 * ADC_VALUE / ADC_READ_MAX + 420.5
 	 */
 	{"ECTemp", LM4_ADC_SEQ0, -225, ADC_READ_MAX, 420,
-	 LM4_AIN_NONE, 0x0e /* TS0 | IE0 | END0 */},
+	 LM4_AIN_NONE, 0x0e /* TS0 | IE0 | END0 */, 0, 0},
 
 	/* Charger current is mapped from 0~4000mA to 0~1.6V.
 	 * And ADC maps 0~3.3V to ADC_READ_MAX.
 	 */
 	{"ChargerCurrent", LM4_ADC_SEQ1, 33 * 4000, ADC_READ_MAX * 16, 0,
-	 LM4_AIN(11), 0x06 /* IE0 | END0 */},
+	 LM4_AIN(11), 0x06 /* IE0 | END0 */, LM4_GPIO_B, (1<<5)},
 };
 
 /* I2C ports */
diff --git a/board/spring/board.c b/board/spring/board.c
index 5542f2354f..9316aaad52 100644
--- a/board/spring/board.c
+++ b/board/spring/board.c
@@ -99,11 +99,11 @@ const struct gpio_info gpio_list[GPIO_COUNT] = {
 /* ADC channels */
 const struct adc_t adc_channels[ADC_CH_COUNT] = {
 	/* Micro USB ID pin. Raw ADC value. */
-	[ADC_CH_USB_ID] = {"USB_ID", 0, 1, 1, 0, STM32_AIN(5), 0},
+	[ADC_CH_USB_ID] = {"USB_ID", 1, 1, 0, STM32_AIN(5)},
 	/* Micro USB D+ sense pin. Raw ADC value. */
-	[ADC_CH_USB_DP_SNS] = {"USB_DP_SNS", 0, 1, 1, 0, STM32_AIN(2), 0},
+	[ADC_CH_USB_DP_SNS] = {"USB_DP_SNS", 1, 1, 0, STM32_AIN(2)},
 	/* Micro USB D- sense pin. Raw ADC value. */
-	[ADC_CH_USB_DN_SNS] = {"USB_DN_SNS", 0, 1, 1, 0, STM32_AIN(4), 0},
+	[ADC_CH_USB_DN_SNS] = {"USB_DN_SNS", 1, 1, 0, STM32_AIN(4)},
 };
 
 void configure_board(void)
diff --git a/chip/lm4/adc.c b/chip/lm4/adc.c
index b2d3479eef..3bac9415c5 100644
--- a/chip/lm4/adc.c
+++ b/chip/lm4/adc.c
@@ -16,68 +16,44 @@
 #include "timer.h"
 #include "util.h"
 
-extern const struct adc_t adc_channels[ADC_CH_COUNT];
-
 static task_id_t task_waiting_on_ss[LM4_ADC_SEQ_COUNT];
 
-/* GPIO port and mask for AINs. */
-const uint32_t ain_port[24][2] = {
-	{LM4_GPIO_E, (1<<3)},
-	{LM4_GPIO_E, (1<<2)},
-	{LM4_GPIO_E, (1<<1)},
-	{LM4_GPIO_E, (1<<0)},
-	{LM4_GPIO_D, (1<<7)},
-	{LM4_GPIO_D, (1<<6)},
-	{LM4_GPIO_D, (1<<5)},
-	{LM4_GPIO_D, (1<<4)},
-	{LM4_GPIO_E, (1<<5)},
-	{LM4_GPIO_E, (1<<4)},
-	{LM4_GPIO_B, (1<<4)},
-	{LM4_GPIO_B, (1<<5)},
-	{LM4_GPIO_D, (1<<3)},
-	{LM4_GPIO_D, (1<<2)},
-	{LM4_GPIO_D, (1<<1)},
-	{LM4_GPIO_D, (1<<0)},
-	{LM4_GPIO_K, (1<<0)},
-	{LM4_GPIO_K, (1<<1)},
-	{LM4_GPIO_K, (1<<2)},
-	{LM4_GPIO_K, (1<<3)},
-	{LM4_GPIO_E, (1<<7)},
-	{LM4_GPIO_E, (1<<6)},
-	{LM4_GPIO_N, (1<<1)},
-	{LM4_GPIO_N, (1<<0)},
-};
-
-
 static void configure_gpio(void)
 {
 	int i;
 
 	/* Use analog function for AIN */
 	for (i = 0; i < ADC_CH_COUNT; ++i) {
-		int id = adc_channels[i].channel;
-		if (id != LM4_AIN_NONE)
-			gpio_set_alternate_function(ain_port[id][0],
-						    ain_port[id][1],
+		if (adc_channels[i].gpio_mask) {
+			gpio_set_alternate_function(adc_channels[i].gpio_port,
+						    adc_channels[i].gpio_mask,
 						    1);
+		}
 	}
 }
 
-
-int lm4_adc_flush_and_read(enum lm4_adc_sequencer seq)
+/**
+ * Flush an ADC sequencer and initiate a read.
+ *
+ * @param seq		Sequencer to read
+ * @return Raw ADC value.
+ */
+static int lm4_adc_flush_and_read(enum lm4_adc_sequencer seq)
 {
-	/* TODO: right now we have only a single channel so this is
-	 * simple.  When we have multiple channels, should we...
+	/*
+	 * TODO: right now we have only a single channel so this is simple.
+	 * When we have multiple channels, should we...
 	 *
-	 * 1) Read them all using a timer interrupt, and then return
-	 * the most recent value?  This is lowest-latency for the
-	 * caller, but won't return accurate data if read frequently.
+	 * 1) Read them all using a timer interrupt, and then return the most
+	 * recent value?  This is lowest-latency for the caller, but won't
+	 * return accurate data if read frequently.
 	 *
-	 * 2) Reserve SS3 for reading a single value, and configure it
-	 * on each read?  Needs mutex if we could have multiple
-	 * callers; doesn't matter if just used for debugging.
+	 * 2) Reserve SS3 for reading a single value, and configure it on each
+	 * read?  Needs mutex if we could have multiple callers; doesn't matter
+	 * if just used for debugging.
 	 *
-	 * 3) Both? */
+	 * 3) Both?
+	 */
 	volatile uint32_t scratch  __attribute__((unused));
 	int event;
 
@@ -85,8 +61,10 @@ int lm4_adc_flush_and_read(enum lm4_adc_sequencer seq)
 	while (!(LM4_ADC_SSFSTAT(seq) & 0x100))
 		scratch = LM4_ADC_SSFIFO(seq);
 
-	/* TODO: This assumes we don't have multiple tasks accessing
-	 * the same sequencer. Add mutex lock if needed. */
+	/*
+	 * This assumes we don't have multiple tasks accessing the same
+	 * sequencer. Add mutex lock if needed.
+	 */
 	task_waiting_on_ss[seq] = task_get_current();
 
 	/* Clear the interrupt status */
@@ -105,11 +83,18 @@ int lm4_adc_flush_and_read(enum lm4_adc_sequencer seq)
 	return LM4_ADC_SSFIFO(seq);
 }
 
-
-int lm4_adc_configure(enum lm4_adc_sequencer seq,
-		      int ain_id,
-		      int ssctl)
+/**
+ * Configure an ADC sequencer to be dedicated for an ADC input.
+ *
+ * @param seq		Sequencer to configure
+ * @param ain_id	ADC input to use
+ * @param ssctl		Value for sampler sequencer control register
+ *
+ */
+static void lm4_adc_configure(const struct adc_t *adc)
 {
+	const enum lm4_adc_sequencer seq = adc->sequencer;
+
 	/* Configure sample sequencer */
 	LM4_ADC_ADCACTSS &= ~(0x01 << seq);
 
@@ -117,22 +102,19 @@ int lm4_adc_configure(enum lm4_adc_sequencer seq,
 	LM4_ADC_ADCEMUX = (LM4_ADC_ADCEMUX & ~(0xf << (seq * 4))) | 0x00;
 
 	/* Sample internal temp sensor */
-	if (ain_id != LM4_AIN_NONE) {
-		LM4_ADC_SSMUX(seq) = ain_id & 0xf;
-		LM4_ADC_SSEMUX(seq) = ain_id >> 4;
-	} else {
+	if (adc->channel == LM4_AIN_NONE) {
 		LM4_ADC_SSMUX(seq) = 0x00;
 		LM4_ADC_SSEMUX(seq) = 0x00;
+	} else {
+		LM4_ADC_SSMUX(seq) = adc->channel & 0xf;
+		LM4_ADC_SSEMUX(seq) = adc->channel >> 4;
 	}
-	LM4_ADC_SSCTL(seq) = ssctl;
+	LM4_ADC_SSCTL(seq) = adc->flag;
 
 	/* Enable sample sequencer */
 	LM4_ADC_ADCACTSS |= 0x01 << seq;
-
-	return EC_SUCCESS;
 }
 
-
 int adc_read_channel(enum adc_channel ch)
 {
 	const struct adc_t *adc = adc_channels + ch;
@@ -146,7 +128,9 @@ int adc_read_channel(enum adc_channel ch)
 /*****************************************************************************/
 /* Interrupt handlers */
 
-/* Handles an interrupt on the specified sample sequencer. */
+/**
+ * Handle an interrupt on the specified sample sequencer.
+ */
 static void handle_interrupt(int ss)
 {
 	int id = task_waiting_on_ss[ss];
@@ -159,7 +143,6 @@ static void handle_interrupt(int ss)
 		task_wake(id);
 }
 
-
 static void ss0_interrupt(void) { handle_interrupt(0); }
 static void ss1_interrupt(void) { handle_interrupt(1); }
 static void ss2_interrupt(void) { handle_interrupt(2); }
@@ -173,7 +156,7 @@ DECLARE_IRQ(LM4_IRQ_ADC0_SS3, ss3_interrupt, 2);
 /*****************************************************************************/
 /* Console commands */
 
-#ifdef CONSOLE_COMMAND_ECTEMP
+#ifdef CONFIG_CMD_ECTEMP
 static int command_ectemp(int argc, char **argv)
 {
 	int t = adc_read_channel(ADC_CH_EC_TEMP);
@@ -186,7 +169,6 @@ DECLARE_CONSOLE_COMMAND(ectemp, command_ectemp,
 			NULL);
 #endif
 
-
 static int command_adc(int argc, char **argv)
 {
 	int i;
@@ -208,7 +190,6 @@ DECLARE_CONSOLE_COMMAND(adc, command_adc,
 static void adc_init(void)
 {
 	int i;
-	const struct adc_t *adc;
 
 	/* Configure GPIOs */
 	configure_gpio();
@@ -248,9 +229,7 @@ static void adc_init(void)
 	task_enable_irq(LM4_IRQ_ADC0_SS3);
 
 	/* Initialize ADC sequencer */
-	for (i = 0; i < ADC_CH_COUNT; ++i) {
-		adc = adc_channels + i;
-		lm4_adc_configure(adc->sequencer, adc->channel, adc->flag);
-	}
+	for (i = 0; i < ADC_CH_COUNT; ++i)
+		lm4_adc_configure(adc_channels + i);
 }
 DECLARE_HOOK(HOOK_INIT, adc_init, HOOK_PRIO_DEFAULT);
diff --git a/chip/lm4/lm4_adc.h b/chip/lm4/lm4_adc.h
index 98f5293646..69479ac265 100644
--- a/chip/lm4/lm4_adc.h
+++ b/chip/lm4/lm4_adc.h
@@ -14,11 +14,25 @@ enum lm4_adc_sequencer
 	LM4_ADC_SEQ1,
 	LM4_ADC_SEQ2,
 	LM4_ADC_SEQ3,
-
 	LM4_ADC_SEQ_COUNT
 };
 
-/* Minimum and maximum values returned by lm4_adc_flush_and_read(). */
+/* Data structure to define ADC channels. */
+struct adc_t {
+	const char *name;
+	enum lm4_adc_sequencer sequencer;
+	int factor_mul;
+	int factor_div;
+	int shift;
+	int channel;
+	int flag;
+	uint32_t gpio_port;
+	uint8_t gpio_mask;
+};
+
+extern const struct adc_t adc_channels[ADC_CH_COUNT];
+
+/* Minimum and maximum values returned by raw ADC read. */
 #define ADC_READ_MIN 0
 #define ADC_READ_MAX 4095
 
@@ -31,12 +45,4 @@ enum lm4_adc_sequencer
 /* Dummy value for "channel" in adc_t if we don't have an external channel. */
 #define LM4_AIN_NONE (-1)
 
-/* Flush an ADC sequencer and initiate a read. Return raw ADC value. */
-int lm4_adc_flush_and_read(enum lm4_adc_sequencer);
-
-/* Configure an ADC sequencer to be dedicated for an ADC input "ain_id".
- * Value in "ssctl" field is passed to sampler sequencer control register.
- */
-int lm4_adc_configure(enum lm4_adc_sequencer, int ain_id, int ssctl);
-
 #endif /* __CROS_EC_LM4_ADC_H */
diff --git a/chip/stm32/stm32_adc.h b/chip/stm32/stm32_adc.h
index 01e67c603b..d67459972c 100644
--- a/chip/stm32/stm32_adc.h
+++ b/chip/stm32/stm32_adc.h
@@ -8,6 +8,15 @@
 #ifndef __CROS_EC_STM32_ADC_H
 #define __CROS_EC_STM32_ADC_H
 
+/* Data structure to define ADC channels. */
+struct adc_t {
+	const char *name;
+	int factor_mul;
+	int factor_div;
+	int shift;
+	int channel;
+};
+
 extern const struct adc_t adc_channels[ADC_CH_COUNT];
 
 /* Minimum and maximum values returned by adc_read_channel(). */
diff --git a/include/adc.h b/include/adc.h
index fe1296cc3b..646298ca76 100644
--- a/include/adc.h
+++ b/include/adc.h
@@ -9,24 +9,24 @@
 #define __CROS_EC_ADC_H
 
 #include "common.h"
-#include "board.h"
 
-/* Data structure to define ADC channels. */
-struct adc_t
-{
-	const char* name;
-	int sequencer;
-	int factor_mul;
-	int factor_div;
-	int shift;
-	int channel;
-	int flag;
-};
-
-/* Read ADC channel. */
+/**
+ * Read an ADC channel.
+ *
+ * @param ch		Channel to read
+ *
+ * @return The scaled ADC value, or ADC_READ_ERROR if error.
+ */
 int adc_read_channel(enum adc_channel ch);
 
-/* Read all ADC channels. Return non-zero on error. */
+/**
+ * Read all ADC channels.
+ *
+ * @param data		Destination array for channel data; must be
+ *			ADC_CH_COUNT elements long.
+ *
+ * @return EC_SUCCESS, or non-zero on error.
+ */
 int adc_read_all_channels(int *data);
 
 #endif  /* __CROS_EC_ADC_H */