Merge "Refactor ADC code and add Link charger current ADC support"

8 files changed, 180 insertions, 92 deletions

diff --git a/board/bds/board.c b/board/bds/board.c
index 71bc810444..631cf29079 100644
--- a/board/bds/board.c
+++ b/board/bds/board.c
@@ -9,6 +9,25 @@
 #include "power_button.h"
 #include "registers.h"
 #include "util.h"
+#include "lm4_adc.h"
+#include "adc.h"
+
+/* ADC channels. Must be in the exactly same order as in enum adc_channel. */
+const struct adc_t adc_channels[ADC_CH_COUNT] =
+{
+	/* EC internal temperature is calculated by
+	 * 273 + (295 - 450 * ADC_VALUE / ADC_READ_MAX) / 2
+	 * = -225 * ADC_VALUE / ADC_READ_MAX + 420.5
+	 */
+	{"ECTemp", LM4_ADC_SEQ0, -225, ADC_READ_MAX, 420,
+	 LM4_NO_AIN, 0x0e /* TS0 | IE0 | END0 */},
+
+	/* 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(ADC_IN0), 0x06 /* IE0 | END0 */},
+};
 
 
 /* GPIO signal list.  Must match order from enum gpio_signal. */
diff --git a/board/bds/board.h b/board/bds/board.h
index 9b28cd6e46..fbd4f153ca 100644
--- a/board/bds/board.h
+++ b/board/bds/board.h
@@ -46,6 +46,16 @@
 /* TODO: really just need a lookup table for channels to inputs */
 #define ADC_IN0 0  /* Turn POT on badger board */
 
+enum adc_channel
+{
+	/* EC internal die temperature in degrees K. */
+	ADC_CH_EC_TEMP = 0,
+	/* Treat BDS pot input as charger current. */
+	ADC_CH_CHARGER_CURRENT,
+
+	ADC_CH_COUNT
+};
+
 /* I2C ports */
 #define I2C_PORT_BATTERY 5  // port 0 / PB2:3 on Link, open on badger
 #define I2C_PORT_CHARGER 5  // port 1 / PA6:7 on Link, user LED on badger
diff --git a/board/link/board.c b/board/link/board.c
index 20a2437b00..67d975686e 100644
--- a/board/link/board.c
+++ b/board/link/board.c
@@ -11,6 +11,8 @@
 #include "registers.h"
 #include "util.h"
 #include "x86_power.h"
+#include "lm4_adc.h"
+#include "adc.h"
 
 #ifndef CONFIG_TASK_X86POWER
 #define x86_power_interrupt NULL
@@ -99,6 +101,22 @@ const struct gpio_info gpio_list[GPIO_COUNT] = {
 	{"USB2_ILIM_SEL",       LM4_GPIO_E, (1<<0), GPIO_OUT_LOW, NULL},
 };
 
+/* ADC channels. Must be in the exactly same order as in enum adc_channel. */
+const struct adc_t adc_channels[ADC_CH_COUNT] =
+{
+	/* EC internal temperature is calculated by
+	 * 273 + (295 - 450 * ADC_VALUE / ADC_READ_MAX) / 2
+	 * = -225 * ADC_VALUE / ADC_READ_MAX + 420.5
+	 */
+	{"ECTemp", LM4_ADC_SEQ0, -225, ADC_READ_MAX, 420,
+	 LM4_NO_AIN, 0x0e /* TS0 | IE0 | END0 */},
+
+	/* 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(ADC_IN0), 0x06 /* IE0 | END0 */},
+};
 
 void configure_board(void)
 {
diff --git a/board/link/board.h b/board/link/board.h
index 923ae716ad..0387bc45fc 100644
--- a/board/link/board.h
+++ b/board/link/board.h
@@ -46,6 +46,16 @@
 /* TODO: assign real ADC inputs */
 #define ADC_IN0 11  /* Charger current */
 
+enum adc_channel
+{
+	/* EC internal die temperature in degrees K. */
+	ADC_CH_EC_TEMP = 0,
+	/* Charger current in mA. */
+	ADC_CH_CHARGER_CURRENT,
+
+	ADC_CH_COUNT
+};
+
 /* I2C ports */
 #define I2C_PORT_BATTERY 0
 #define I2C_PORT_CHARGER 1
diff --git a/chip/lm4/adc.c b/chip/lm4/adc.c
index 531411fd21..740c9a623d 100644
--- a/chip/lm4/adc.c
+++ b/chip/lm4/adc.c
@@ -3,9 +3,9 @@
  * found in the LICENSE file.
  */
 
-/* ADC module for Chrome EC */
+/* LM4-specific ADC module for Chrome EC */
 
-#include "board.h"
+#include "lm4_adc.h"
 #include "console.h"
 #include "adc.h"
 #include "timer.h"
@@ -13,6 +13,7 @@
 #include "uart.h"
 #include "util.h"
 
+extern const struct adc_t adc_channels[ADC_CH_COUNT];
 
 static void configure_gpio(void)
 {
@@ -22,16 +23,13 @@ static void configure_gpio(void)
 	LM4_SYSTEM_RCGCGPIO |= 0x0010;
 	scratch = LM4_SYSTEM_RCGCGPIO;
 
-        /* Use analog function for PE3 (AIN0) */
+	/* Use analog function for PE3 (AIN0) */
 	LM4_GPIO_DEN(LM4_GPIO_E) &= ~0x08;
 	LM4_GPIO_AMSEL(LM4_GPIO_E) |= 0x08;
 }
 
-
-int adc_read(enum adc_channel ch)
+int lm4_adc_flush_and_read(enum lm4_adc_sequencer seq)
 {
-	volatile uint32_t scratch  __attribute__((unused));
-
 	/* TODO: right now we have only a single channel so this is
 	 * simple.  When we have multiple channels, should we...
 	 *
@@ -44,84 +42,95 @@ int adc_read(enum adc_channel ch)
 	 * callers; doesn't matter if just used for debugging.
 	 *
 	 * 3) Both? */
-	if (ch != ADC_CH_POT)
-		return ADC_READ_ERROR;
-
-	/* Empty the FIFO of any previous results */
-	while (!(LM4_ADC_SSFSTAT(0) & 0x100))
-		scratch = LM4_ADC_SSFIFO(0);
-
-	/* Clear the interrupt status */
-	LM4_ADC_ADCISC |= 0x01;
-
-	/* Initiate sample sequence */
-	LM4_ADC_ADCPSSI |= 0x01;
-
-	/* Wait for interrupt */
-	/* TODO: use a real interrupt */
-	while (!(LM4_ADC_ADCRIS & 0x01));
-
-	/* Read the FIFO */
-	return LM4_ADC_SSFIFO(0);
-}
-
-
-int adc_read_ec_temperature(void)
-{
 	volatile uint32_t scratch  __attribute__((unused));
-	int a;
 
 	/* Empty the FIFO of any previous results */
-	while (!(LM4_ADC_SSFSTAT(3) & 0x100))
-		scratch = LM4_ADC_SSFIFO(3);
+	while (!(LM4_ADC_SSFSTAT(seq) & 0x100))
+		scratch = LM4_ADC_SSFIFO(seq);
 
 	/* Clear the interrupt status */
-	LM4_ADC_ADCISC |= 0x08;
+	LM4_ADC_ADCISC |= 0x01 << seq;
 
 	/* Initiate sample sequence */
-	LM4_ADC_ADCPSSI |= 0x08;
+	LM4_ADC_ADCPSSI |= 0x01 << seq;
 
 	/* Wait for interrupt */
 	/* TODO: use a real interrupt */
 	/* TODO: timeout */
-	while (!(LM4_ADC_ADCRIS & 0x08));
+	while (!(LM4_ADC_ADCRIS & (0x01 << seq)));
 
 	/* Read the FIFO and convert to temperature */
-	a = LM4_ADC_SSFIFO(3);
-	return 273 + (295 - (225 * 2 * a) / ADC_READ_MAX) / 2;
+	return LM4_ADC_SSFIFO(seq);
 }
 
+int lm4_adc_configure(enum lm4_adc_sequencer seq,
+		      int ain_id,
+		      int ssctl)
+{
+	volatile uint32_t scratch  __attribute__((unused));
+	/* TODO: set up clock using ADCCC register? */
+	/* Configure sample sequencer */
+	LM4_ADC_ADCACTSS &= ~(0x01 << seq);
+	/* Trigger sequencer by processor request */
+	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 {
+		LM4_ADC_SSMUX(seq) = 0x00;
+		LM4_ADC_SSEMUX(seq) = 0x00;
+	}
+	LM4_ADC_SSCTL(seq) = ssctl;
+	/* Enable sample sequencer */
+	LM4_ADC_ADCACTSS |= 0x01 << seq;
 
-/*****************************************************************************/
-/* Console commands */
+	return EC_SUCCESS;
+}
 
-static int command_adc(int argc, char **argv)
+int adc_read_channel(enum adc_channel ch)
 {
-	uart_printf("ADC channel %d = 0x%03x\n", ADC_IN0,
-		    adc_read(ADC_CH_POT));
-	return EC_SUCCESS;
+	const struct adc_t *adc = adc_channels + ch;
+	int rv = lm4_adc_flush_and_read(adc->sequencer);
+	return rv * adc->factor_mul / adc->factor_div + adc->shift;
 }
-DECLARE_CONSOLE_COMMAND(adc, command_adc);
 
+/*****************************************************************************/
+/* Console commands */
 
 static int command_ectemp(int argc, char **argv)
 {
-	int t = adc_read_ec_temperature();
+	int t = adc_read_channel(ADC_CH_EC_TEMP);
 	uart_printf("EC temperature is %d K = %d C\n", t, t-273);
 	return EC_SUCCESS;
 }
 DECLARE_CONSOLE_COMMAND(ectemp, command_ectemp);
 
+static int command_adc(int argc, char **argv)
+{
+	int i;
 
+	for (i = 0; i < ADC_CH_COUNT; ++i)
+		uart_printf("ADC channel \"%s\" = %d\n",
+			     adc_channels[i].name,
+			     adc_read_channel(i));
+
+	return EC_SUCCESS;
+}
+DECLARE_CONSOLE_COMMAND(adc, command_adc);
+
+/*****************************************************************************/
 /* Initialization */
 
 int adc_init(void)
 {
-	volatile uint32_t scratch  __attribute__((unused));
+	int i;
+	const struct adc_t *adc;
 
         /* Enable ADC0 module and delay a few clocks */
 	LM4_SYSTEM_RCGCADC |= 0x01;
-	scratch = LM4_SYSTEM_RCGCADC;
+	udelay(1);
 
 	/* Configure GPIOs */
 	configure_gpio();
@@ -130,29 +139,11 @@ int adc_init(void)
 	 * VDDA and GNDA. */
 	LM4_ADC_ADCCTL = 0x01;
 
-	/* TODO: set up clock using ADCCC register? */
-
-	/* Configure sample sequencer 0 */
-	LM4_ADC_ADCACTSS &= ~0x01;
-	/* Trigger SS0 by processor request */
-	LM4_ADC_ADCEMUX = (LM4_ADC_ADCEMUX & 0xfffffff0) | 0x00;
-	/* Sample only our one channel */
-	LM4_ADC_SSMUX(0) = ADC_IN0 & 0x0f;
-	LM4_ADC_SSEMUX(0) = (ADC_IN0 >> 4) & 0x0f;
-	LM4_ADC_SSCTL(0) = 0x06;  /* IE0 | END0 */
-	/* Enable sample sequencer 0 */
-	LM4_ADC_ADCACTSS |= 0x01;
-
-	/* Configure sample sequencer 3 */
-	LM4_ADC_ADCACTSS &= ~0x08;
-	/* Trigger SS3 by processor request */
-	LM4_ADC_ADCEMUX = (LM4_ADC_ADCEMUX & 0xffffff0f) | 0x00;
-	/* Sample internal temp sensor */
-	LM4_ADC_SSMUX(3) = 0x00;
-	LM4_ADC_SSEMUX(3) = 0x00;
-	LM4_ADC_SSCTL(3) = 0x0e;  /* TS0 | IE0 | END0 */
-	/* Enable sample sequencer 3 */
-	LM4_ADC_ADCACTSS |= 0x08;
+	/* Initialize ADC sequencer */
+	for (i = 0; i < ADC_CH_COUNT; ++i) {
+		adc = adc_channels + i;
+		lm4_adc_configure(adc->sequencer, adc->channel, adc->flag);
+	}
 
 	return EC_SUCCESS;
 }
diff --git a/chip/lm4/lm4_adc.h b/chip/lm4/lm4_adc.h
new file mode 100644
index 0000000000..dad05be703
--- /dev/null
+++ b/chip/lm4/lm4_adc.h
@@ -0,0 +1,43 @@
+/* Copyright (c) 2012 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.
+ */
+
+/* LM4-specific ADC module for Chrome EC */
+
+#ifndef __CROS_EC_LM4_ADC_H
+#define __CROS_EC_LM4_ADC_H
+
+enum lm4_adc_sequencer
+{
+	LM4_ADC_SEQ0 = 0,
+	LM4_ADC_SEQ1,
+	LM4_ADC_SEQ2,
+	LM4_ADC_SEQ3,
+
+	LM4_ADC_SEQ_COUNT
+};
+
+/* Minimum and maximum values returned by lm4_adc_flush_and_read(). */
+#define ADC_READ_MIN 0
+#define ADC_READ_MAX 4095
+
+/* Value returned if the read failed. */
+#define ADC_READ_ERROR -1
+
+/* Just plain id mapping for code readability */
+#define LM4_AIN(x) (x)
+#define LM4_AIN_NONE (-1)
+
+/* Dummy value for "channel" in adc_t if we don't have an external channel. */
+#define LM4_NO_AIN 0
+
+/* 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/lm4/temp_sensor.c b/chip/lm4/temp_sensor.c
index 7755bcf140..a9095bf380 100644
--- a/chip/lm4/temp_sensor.c
+++ b/chip/lm4/temp_sensor.c
@@ -53,11 +53,11 @@ int temp_sensor_read(enum temp_sensor_id id)
 			return -1;
 		t = (int)(int16_t)traw / 128;
 		return t + 273;
-
 	case TEMP_SENSOR_EC_INTERNAL:
-		return adc_read_ec_temperature();
+		return adc_read_channel(ADC_CH_EC_TEMP);
+	default:
+		return -1;
 	}
-
 	/* If we're still here, we don't handle that sensor */
 	return -1;
 }
diff --git a/include/adc.h b/include/adc.h
index 1f01f2c08f..a59c58c463 100644
--- a/include/adc.h
+++ b/include/adc.h
@@ -9,27 +9,24 @@
 #define __CROS_EC_ADC_H
 
 #include "common.h"
-
-/* Value returned by adc_read_*() methods if the read failed. */
-#define ADC_READ_ERROR -1
-
-/* Minimum and maximum values returned by adc_read(). */
-#define ADC_READ_MIN 0
-#define ADC_READ_MAX 4095
-
-/* ADC channels */
-/* TODO: channel mapping is board-specific */
-enum adc_channel {
-	ADC_CH_POT = 0,
+#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;
 };
 
 /* Initializes the module. */
 int adc_init(void);
 
-/* Reads an ADC channel.  Returns the ADC value, or ADC_READ_ERROR if error. */
-int adc_read(enum adc_channel ch);
-
-/* Returns the internal EC temperature in K, or ADC_READ_ERROR if error. */
-int adc_read_ec_temperature(void);
+/* Read ADC channel. */
+int adc_read_channel(enum adc_channel ch);
 
 #endif  /* __CROS_EC_ADC_H */