iPod Classic: ADC updates

Add code to read USB D+/D- and accessory ADCs, it is shown in HW
debug menu, might be useful in future for RB and/or the bootloader
to identify external USB chargers.

Change-Id: Ia48ca5e06bb7ddc52bb55abedde6734653ce8dba

7 files changed, 201 insertions, 57 deletions

diff --git a/firmware/export/pcf5063x.h b/firmware/export/pcf5063x.h
index f5f177ace7..2751b67b57 100644
--- a/firmware/export/pcf5063x.h
+++ b/firmware/export/pcf5063x.h
@@ -198,12 +198,12 @@ enum pcf5063X_reg_mbcc2 {
 
 enum pcf5063X_reg_adcc1 {
         PCF5063X_ADCC1_ADCSTART         = 0x01,
-        PCF5063X_ADCC1_RES_10BIT        = 0x02,
+        PCF5063X_ADCC1_RES_10BIT        = 0x00,
+        PCF5063X_ADCC1_RES_8BIT         = 0x02,
         PCF5063X_ADCC1_AVERAGE_NO       = 0x00,
         PCF5063X_ADCC1_AVERAGE_4        = 0x04,
         PCF5063X_ADCC1_AVERAGE_8        = 0x08,
         PCF5063X_ADCC1_AVERAGE_16       = 0x0c,
-
         PCF5063X_ADCC1_MUX_BATSNS_RES   = 0x00,
         PCF5063X_ADCC1_MUX_BATSNS_SUBTR = 0x10,
         PCF5063X_ADCC1_MUX_ADCIN2_RES   = 0x20,
@@ -211,6 +211,7 @@ enum pcf5063X_reg_adcc1 {
         PCF5063X_ADCC1_MUX_BATTEMP      = 0x60,
         PCF5063X_ADCC1_MUX_ADCIN1       = 0x70,
 };
+#define PCF5063X_ADCC1_RES_MASK         0x02
 #define PCF5063X_ADCC1_AVERAGE_MASK     0x0c
 #define PCF5063X_ADCC1_ADCMUX_MASK      0xf0
 
@@ -219,9 +220,11 @@ enum pcf5063X_reg_adcc2 {
         PCF5063X_ADCC2_RATIO_BATTEMP    = 0x01,
         PCF5063X_ADCC2_RATIO_ADCIN1     = 0x02,
         PCF5063X_ADCC2_RATIO_BOTH       = 0x03,
+        PCF5063X_ADCC2_RATIOSETTL_10US  = 0x00,
         PCF5063X_ADCC2_RATIOSETTL_100US = 0x04,
 };
 #define PCF5063X_ADCC2_RATIO_MASK       0x03
+#define PCF5063X_ADCC2_RATIOSETTL_MASK  0x04
 
 enum pcf5063X_reg_adcc3 {
         PCF5063X_ADCC3_ACCSW_EN         = 0x01,
@@ -229,6 +232,7 @@ enum pcf5063X_reg_adcc3 {
         PCF5063X_ADCC3_RES_DIV_TWO      = 0x10,
         PCF5063X_ADCC3_RES_DIV_THREE    = 0x00,
 };
+#define PCF5063X_ADCC3_RES_DIV_MASK     0x10
 
 enum pcf5063X_reg_adcs3 {
         PCF5063X_ADCS3_REF_NTCSW        = 0x00,
diff --git a/firmware/target/arm/s5l8702/debug-s5l8702.c b/firmware/target/arm/s5l8702/debug-s5l8702.c
index a61a728d43..1bf59e94fe 100644
--- a/firmware/target/arm/s5l8702/debug-s5l8702.c
+++ b/firmware/target/arm/s5l8702/debug-s5l8702.c
@@ -19,6 +19,7 @@
  *
  ****************************************************************************/
 
+#include <stdio.h>
 #include <stdbool.h>
 #include "system.h"
 #include "config.h"
@@ -28,6 +29,7 @@
 #include "font.h"
 #include "storage.h"
 #include "power.h"
+#include "adc.h"
 #include "pmu-target.h"
 #include "pcm-target.h"
 #ifdef HAVE_SERIAL
@@ -134,11 +136,19 @@ bool dbg_hw_info(void)
                             pmu_accessory_present() ? "true" : "false");
 #endif
             line++;
+            _DEBUG_PRINTF("ADC:");
+            _DEBUG_PRINTF("%s: %d mV", adc_name(ADC_BATTERY),
+                            adc_read_battery_voltage());
+            _DEBUG_PRINTF("%s: %d Ohms", adc_name(ADC_ACCESSORY),
+                            adc_read_accessory_resistor());
+            _DEBUG_PRINTF("USB D+: %d mV", adc_read_usbdata_voltage(true));
+            _DEBUG_PRINTF("USB D-: %d mV", adc_read_usbdata_voltage(false));
+            line++;
             extern unsigned long i2c_rd_err, i2c_wr_err;
             _DEBUG_PRINTF("i2c rd/wr errors: %lu/%lu", i2c_rd_err, i2c_wr_err);
         }
 #ifdef UC870X_DEBUG
-        else if(state==2)
+        else if(state==(max_states-1))
         {
             extern struct uartc_port ser_port;
             bool opened = !!ser_port.uartc->port_l[ser_port.id];
diff --git a/firmware/target/arm/s5l8702/ipod6g/adc-ipod6g.c b/firmware/target/arm/s5l8702/ipod6g/adc-ipod6g.c
index 201af5ee00..fbe5ef805e 100644
--- a/firmware/target/arm/s5l8702/ipod6g/adc-ipod6g.c
+++ b/firmware/target/arm/s5l8702/ipod6g/adc-ipod6g.c
@@ -18,7 +18,7 @@
  * KIND, either express or implied.
  *
  ****************************************************************************/
- 
+
 #include "config.h"
 
 #include "inttypes.h"
@@ -28,12 +28,90 @@
 #include "pmu-target.h"
 #include "kernel.h"
 
+
+/* MS_TO_TICKS converts a milisecond time period into the
+ * corresponding amount of ticks. If the time period cannot
+ * be accurately measured in ticks it will round up.
+ */
+#define MS_PER_HZ (1000/HZ)
+#define MS_TO_TICKS(x) (((x)+MS_PER_HZ-1)/MS_PER_HZ)
+
+static const struct pmu_adc_channel adc_channels[] =
+{
+    [ADC_BATTERY] =
+    {
+        .name = "Battery",
+        .adcc1 = PCF5063X_ADCC1_MUX_BATSNS_SUBTR
+               | PCF5063X_ADCC1_AVERAGE_4
+               | PCF5063X_ADCC1_RES_10BIT,
+    },
+
+    [ADC_USBDATA] =
+    {
+        .name = "USB D+/D-",
+        .adcc1 = PCF5063X_ADCC1_MUX_ADCIN2_RES
+               | PCF5063X_ADCC1_AVERAGE_16
+               | PCF5063X_ADCC1_RES_10BIT,
+        .adcc3 = PCF5063X_ADCC3_RES_DIV_THREE,
+    },
+
+    [ADC_ACCESSORY] =
+    {
+        .name = "Accessory",
+        .adcc1 = PCF5063X_ADCC1_MUX_ADCIN1
+               | PCF5063X_ADCC1_AVERAGE_16
+               | PCF5063X_ADCC1_RES_10BIT,
+        .adcc2 = PCF5063X_ADCC2_RATIO_ADCIN1
+               | PCF5063X_ADCC2_RATIOSETTL_10US,
+        .adcc3 = PCF5063X_ADCC3_ACCSW_EN,
+        .bias_dly = MS_TO_TICKS(50),
+    },
+};
+
+const char *adc_name(int channel)
+{
+    return adc_channels[channel].name;
+}
+
+unsigned short adc_read_millivolts(int channel)
+{
+    const struct pmu_adc_channel *ch = &adc_channels[channel];
+    return pmu_adc_raw2mv(ch, pmu_read_adc(ch));
+}
+
+/* Returns battery voltage [millivolts] */
+unsigned int adc_read_battery_voltage(void)
+{
+    return adc_read_millivolts(ADC_BATTERY);
+}
+
+/* Returns USB D+/D- voltage from ADC [millivolts] */
+unsigned int adc_read_usbdata_voltage(bool dp)
+{
+    unsigned int mvolts;
+    int gpio = dp ? 0xb0300 : 0xb0200; /* select D+/D- */
+    GPIOCMD = gpio | 0xf; /* route to ADCIN2 */
+    mvolts = adc_read_millivolts(ADC_USBDATA);
+    GPIOCMD = gpio | 0xe; /* unroute */
+    return mvolts;
+}
+
+/* Returns resistor connected to "Accessory identify" pin [ohms] */
+#define IAP_DEVICE_RESISTOR 100000  /* ohms */
+int adc_read_accessory_resistor(void)
+{
+    int raw = pmu_read_adc(&adc_channels[ADC_ACCESSORY]);
+    return (1023-raw) ? raw * IAP_DEVICE_RESISTOR / (1023-raw)
+                      : -1 /* open circuit */;
+}
+
+
+/* API functions */
 unsigned short adc_read(int channel)
 {
-    return pmu_read_adc(channel);
+    return pmu_read_adc(&adc_channels[channel]);
 }
 
 void adc_init(void)
 {
 }
-
diff --git a/firmware/target/arm/s5l8702/ipod6g/adc-target.h b/firmware/target/arm/s5l8702/ipod6g/adc-target.h
index d4dce3d31f..bedc0a8447 100644
--- a/firmware/target/arm/s5l8702/ipod6g/adc-target.h
+++ b/firmware/target/arm/s5l8702/ipod6g/adc-target.h
@@ -21,13 +21,23 @@
 #ifndef _ADC_TARGET_H_
 #define _ADC_TARGET_H_
 
-#define NUM_ADC_CHANNELS 4
+#include <stdbool.h>
+#include "config.h"
 
-#define ADC_UNKNOWN_0   0
-#define ADC_UNKNOWN_1   1
-#define ADC_BATTERY     2
-#define ADC_UNKNOWN_3   3
+enum
+{
+    ADC_BATTERY = 0,
+    ADC_USBDATA,
+    ADC_ACCESSORY,
+    NUM_ADC_CHANNELS
+};
 
 #define ADC_UNREG_POWER ADC_BATTERY /* For compatibility */
 
+unsigned short adc_read_millivolts(int channel);
+unsigned int adc_read_battery_voltage(void);
+unsigned int adc_read_usbdata_voltage(bool dp);
+int adc_read_accessory_resistor(void);
+const char *adc_name(int channel);
+
 #endif
diff --git a/firmware/target/arm/s5l8702/ipod6g/pmu-ipod6g.c b/firmware/target/arm/s5l8702/ipod6g/pmu-ipod6g.c
index c439a30fc1..d282a48d5b 100644
--- a/firmware/target/arm/s5l8702/ipod6g/pmu-ipod6g.c
+++ b/firmware/target/arm/s5l8702/ipod6g/pmu-ipod6g.c
@@ -24,12 +24,11 @@
 #include "thread.h"
 
 #include "pmu-target.h"
+#include "adc-target.h"
 #include "i2c-s5l8702.h"
 #include "gpio-s5l8702.h"
 
 
-static struct mutex pmu_adc_mutex;
-
 int pmu_read_multiple(int address, int count, unsigned char* buffer)
 {
     return i2c_read(0, 0xe6, address, count, buffer);
@@ -54,35 +53,6 @@ int pmu_write(int address, unsigned char val)
     return pmu_write_multiple(address, 1, &val);
 }
 
-int pmu_read_adc(unsigned int adc)
-{
-    int data = 0;
-    mutex_lock(&pmu_adc_mutex);
-    pmu_write(0x54, 5 | (adc << 4));
-    while ((data & 0x80) == 0)
-    {
-        yield();
-        data = pmu_read(0x57);
-    }
-    int value = (pmu_read(0x55) << 2) | (data & 3);
-    mutex_unlock(&pmu_adc_mutex);
-    return value;
-}
-
-/* millivolts */
-int pmu_read_battery_voltage(void)
-{
-    return (pmu_read_adc(1) * 2000 / 1023) + 2250;
-}
-
-/* milliamps */
-int pmu_read_battery_current(void)
-{
-//TODO: Figure out how to read the battery current
-//    return pmu_read_adc(2);
-    return 0;
-}
-
 void pmu_ldo_on_in_standby(unsigned int ldo, int onoff)
 {
     if (ldo < 4)
@@ -143,17 +113,86 @@ void pmu_write_rtc(unsigned char* buffer)
 }
 
 /*
+ * ADC
+ */
+#define ADC_FULL_SCALE          2000
+#define ADC_FULL_SCALE_VISA     2400
+#define ADC_SUBTR_OFFSET        2250
+
+static struct mutex pmu_adc_mutex;
+
+/* converts raw 8/10-bit value to millivolts */
+unsigned short pmu_adc_raw2mv(
+        const struct pmu_adc_channel *ch, unsigned short raw)
+{
+    int full_scale = ADC_FULL_SCALE;
+    int offset = 0;
+
+    switch (ch->adcc1 & PCF5063X_ADCC1_ADCMUX_MASK)
+    {
+        case PCF5063X_ADCC1_MUX_BATSNS_RES:
+        case PCF5063X_ADCC1_MUX_ADCIN2_RES:
+            full_scale *= ((ch->adcc1 & PCF5063X_ADCC3_RES_DIV_MASK) ==
+                                        PCF5063X_ADCC3_RES_DIV_TWO) ? 2 : 3;
+            break;
+        case PCF5063X_ADCC1_MUX_BATSNS_SUBTR:
+        case PCF5063X_ADCC1_MUX_ADCIN2_SUBTR:
+            offset = ADC_SUBTR_OFFSET;
+            break;
+        case PCF5063X_ADCC1_MUX_BATTEMP:
+            if (ch->adcc2 & PCF5063X_ADCC2_RATIO_BATTEMP)
+                full_scale = ADC_FULL_SCALE_VISA;
+            break;
+        case PCF5063X_ADCC1_MUX_ADCIN1:
+            if (ch->adcc2 & PCF5063X_ADCC2_RATIO_ADCIN1)
+                full_scale = ADC_FULL_SCALE_VISA;
+            break;
+    }
+
+    int nrb = ((ch->adcc1 & PCF5063X_ADCC1_RES_MASK) ==
+                                PCF5063X_ADCC1_RES_8BIT) ? 8 : 10;
+    return (raw * full_scale / ((1<<nrb)-1)) + offset;
+}
+
+/* returns raw value, 8 or 10-bit resolution */
+unsigned short pmu_read_adc(const struct pmu_adc_channel *ch)
+{
+    mutex_lock(&pmu_adc_mutex);
+
+    pmu_write(PCF5063X_REG_ADCC3, ch->adcc3);
+    if (ch->bias_dly)
+        sleep(ch->bias_dly);
+    uint8_t buf[2] = { ch->adcc2, ch->adcc1 | PCF5063X_ADCC1_ADCSTART };
+    pmu_write_multiple(PCF5063X_REG_ADCC2, 2, buf);
+
+    int adcs3 = 0;
+    while (!(adcs3 & PCF5063X_ADCS3_ADCRDY))
+    {
+        yield();
+        adcs3 = pmu_read(PCF5063X_REG_ADCS3);
+    }
+
+    int raw = pmu_read(PCF5063X_REG_ADCS1);
+    if ((ch->adcc1 & PCF5063X_ADCC1_RES_MASK) == PCF5063X_ADCC1_RES_10BIT)
+        raw = (raw << 2) | (adcs3 & PCF5063X_ADCS3_ADCDAT1L_MASK);
+
+    mutex_unlock(&pmu_adc_mutex);
+    return raw;
+}
+
+/*
  * eINT
  */
 #define Q_EINT  0
 
-static char pmu_thread_stack[DEFAULT_STACK_SIZE/4];
+static char pmu_thread_stack[DEFAULT_STACK_SIZE/2];
 static struct event_queue pmu_queue;
 static unsigned char ints_msk[6];
 
 static void pmu_eint_isr(struct eint_handler*);
 
-static struct eint_handler pmu_eint = {
+static struct eint_handler pmu_eint =
+{
     .gpio_n = GPIO_EINT_PMU,
     .type   = EIC_INTTYPE_LEVEL,
     .level  = EIC_INTLEVEL_LOW,
@@ -355,10 +394,11 @@ void pmu_preinit(void)
         PCF5063X_REG_STBYCTL1,  0x0,
         PCF5063X_REG_STBYCTL2,  0x8c,
 
-        /* GPIO1,2 = input, GPIO3 = output */
+        /* GPIO1,2 = input, GPIO3 = output High (NoPower default) */
         PCF5063X_REG_GPIOCTL,   0x3,
         PCF5063X_REG_GPIO1CFG,  0x0,
         PCF5063X_REG_GPIO2CFG,  0x0,
+        PCF5063X_REG_GPIO3CFG,  0x7,
 
         /* DOWN2 converter (SDRAM): 1800 mV, enabled,
            startup current limit = 15mA*0x10 (TBC) */
diff --git a/firmware/target/arm/s5l8702/ipod6g/pmu-target.h b/firmware/target/arm/s5l8702/ipod6g/pmu-target.h
index 5552e2196a..d33db42717 100644
--- a/firmware/target/arm/s5l8702/ipod6g/pmu-target.h
+++ b/firmware/target/arm/s5l8702/ipod6g/pmu-target.h
@@ -22,6 +22,7 @@
 #ifndef __PMU_TARGET_H__
 #define __PMU_TARGET_H__
 
+#include <stdint.h>
 #include <stdbool.h>
 #include "config.h"
 
@@ -72,14 +73,22 @@ enum pcf50635_reg_gpiostat {
  *  GPIO3: output, unknown
  */
 
+struct pmu_adc_channel
+{
+    const char *name;
+    uint8_t adcc1;
+    uint8_t adcc2;
+    uint8_t adcc3;
+    uint8_t bias_dly; /* RB ticks */
+};
 
 unsigned char pmu_read(int address);
 int pmu_write(int address, unsigned char val);
 int pmu_read_multiple(int address, int count, unsigned char* buffer);
 int pmu_write_multiple(int address, int count, unsigned char* buffer);
-int pmu_read_adc(unsigned int adc);
-int pmu_read_battery_voltage(void);
-int pmu_read_battery_current(void);
+unsigned short pmu_read_adc(const struct pmu_adc_channel *ch);
+unsigned short pmu_adc_raw2mv(
+        const struct pmu_adc_channel *ch, unsigned short raw);
 void pmu_init(void);
 void pmu_ldo_on_in_standby(unsigned int ldo, int onoff);
 void pmu_ldo_set_voltage(unsigned int ldo, unsigned char voltage);
diff --git a/firmware/target/arm/s5l8702/ipod6g/powermgmt-ipod6g.c b/firmware/target/arm/s5l8702/ipod6g/powermgmt-ipod6g.c
index 4553b03685..c5f9c9b9f5 100644
--- a/firmware/target/arm/s5l8702/ipod6g/powermgmt-ipod6g.c
+++ b/firmware/target/arm/s5l8702/ipod6g/powermgmt-ipod6g.c
@@ -24,6 +24,7 @@
 #include "pmu-target.h"
 #include "power.h"
 #include "audiohw.h"
+#include "adc-target.h"
 
 const unsigned short battery_level_dangerous[BATTERY_TYPES_COUNT] =
 {
@@ -49,20 +50,12 @@ const unsigned short percent_to_volt_charge[11] =
 };
 #endif /* CONFIG_CHARGING */
 
-/* ADC should read 0x3ff=6.00V */
-#define BATTERY_SCALE_FACTOR 6000
-/* full-scale ADC readout (2^10) in millivolt */
-
-
 /* Returns battery voltage from ADC [millivolts] */
 int _battery_voltage(void)
 {
-    int compensation = (10 * (pmu_read_battery_current() - 7)) / 12;
-    if (charging_state()) return pmu_read_battery_voltage() - compensation;
-    return pmu_read_battery_voltage() + compensation;
+    return adc_read_battery_voltage();
 }
 
-
 #ifdef HAVE_ACCESSORY_SUPPLY
 void accessory_supply_set(bool enable)
 {