as3514/as3543 fixes

- Enable end of charge monitoring once, it doesn't need to be disabled
- Acknowledge the first (wrong) end of charge interrupt on charger enable
  (this had been broken in r25299)
- Centralize reads to ENRD* registers and cache the results when needed
    - on PP it is not needed because reads are atomic, we only check for
      end of charge when the charging, and for charger presence when
      discharging

as3525v2 (using as3543) specifics
- I got the datasheet today from AMS, thanks to them for being so fast
  and not require me to sign tons of papers!
- USB detection now works on as3525v2 using the as3543. Clip+ won't
  reboot to OF yet, it needs mkamsboot support first (usbstack disabled)
- Charging should work, the CHARGER register is at a different place, it
  is an extended PMU register -> use ascodec_read/write_charger() to
  access it
- real interrupts are not used yet for ENRD, we get thousands of
  interrupts per second, apparently only limited by the i2c clock.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@26116 a1c6a512-1295-4272-9138-f99709370657

7 files changed, 142 insertions, 92 deletions

diff --git a/firmware/target/arm/as3525/ascodec-as3525.c b/firmware/target/arm/as3525/ascodec-as3525.c
index 87a1447c63..52d50ef077 100644
--- a/firmware/target/arm/as3525/ascodec-as3525.c
+++ b/firmware/target/arm/as3525/ascodec-as3525.c
@@ -185,10 +185,18 @@ void ascodec_init(void)
 
     I2C2_IMR = 0x00;          /* disable interrupts */
     I2C2_INT_CLR |= I2C2_RIS; /* clear interrupt status */
-    VIC_INT_ENABLE = INTERRUPT_I2C_AUDIO | INTERRUPT_AUDIO;
+    VIC_INT_ENABLE = INTERRUPT_I2C_AUDIO;
+#if CONFIG_CPU == AS3525 /* interrupts do not work correctly on as3525v2 */
+    VIC_INT_ENABLE = INTERRUPT_AUDIO;
+#endif
 
     /* Generate irq for usb+charge status change */
-    ascodec_write(AS3514_IRQ_ENRD0, /*IRQ_CHGSTAT |*/ IRQ_USBSTAT);
+    ascodec_write(AS3514_IRQ_ENRD0,
+#ifdef CONFIG_CHARGING /* m200v4 can't charge */
+        IRQ_CHGSTAT | IRQ_ENDOFCH |
+#endif
+        IRQ_USBSTAT);
+
     /* Generate irq for push-pull, active high, irq on rtc+adc change */
     ascodec_write(AS3514_IRQ_ENRD2, IRQ_PUSHPULL | IRQ_HIGHACTIVE |
                                     /*IRQ_RTC |*/ IRQ_ADC);
@@ -342,19 +350,8 @@ static void ascodec_wait(struct ascodec_request *req)
 void ascodec_async_write(unsigned int index, unsigned int value,
                          struct ascodec_request *req)
 {
-    switch(index) {
-    case AS3514_CVDD_DCDC3:
-        /* prevent setting of the LREG_CP_not bit */
+    if (index == AS3514_CVDD_DCDC3) /* prevent setting of the LREG_CP_not bit */
         value &= ~(1 << 5);
-        break;
-    case AS3514_IRQ_ENRD0:
-        /* save value in register shadow
-         * for ascodec_(en|dis)able_endofch_irq() */
-        ascodec_enrd0_shadow = value;
-        break;
-    default:
-        break;
-    }
 
     ascodec_req_init(req, ASCODEC_REQ_WRITE, index, 1);
     req->data[0] = value;
@@ -429,24 +426,37 @@ int ascodec_readbytes(unsigned int index, unsigned int len, unsigned char *data)
     return i;
 }
 
-#if CONFIG_CPU == AS3525
-static void ascodec_read_cb(unsigned const char *data, unsigned int len)
+/*
+ * Reading AS3514_IRQ_ENRD0 clears all interrupt bits, so we cache the results
+ * and clear individual bits when a specific interrupt is checked:
+ * - we clear the ENDOFCH (end of charge) interrupt when it's read
+ * - we set the usb and charger presence when the status change is detected
+ *
+ * on AS3525(v1) ENRD0 is only read in an interrupt handler
+ * on AS3525v2 the interrupt handler doesn't work (yet), so we read the register
+ * synchronously.
+ *  - To avoid race conditions all the reads to this register must be atomic.
+ *    We don't need to disable interrupts when reading it because all the reads
+ *    (in powermgmt-ascodec.c and power-as3525.c) are performed by the same
+ *    thread (the power thread).
+ */
+static void cache_enrd0(int enrd0)
 {
-    if (len != 3) /* some error happened? */
-        return;
-
-    if (data[0] & CHG_ENDOFCH) { /* chg finished */
+    if (enrd0 & CHG_ENDOFCH) { /* chg finished */
+        ascodec_enrd0_shadow |= CHG_ENDOFCH;
         IFDEBUG(int_chg_finished++);
     }
-    if (data[0] & CHG_CHANGED) { /* chg status changed */
-        if (data[0] & CHG_STATUS) {
+    if (enrd0 & CHG_CHANGED) { /* chg status changed */
+        if (enrd0 & CHG_STATUS) {
+            ascodec_enrd0_shadow |= CHG_STATUS;
             IFDEBUG(int_chg_insert++);
         } else {
+            ascodec_enrd0_shadow &= ~CHG_STATUS;
             IFDEBUG(int_chg_remove++);
         }
     }
-    if (data[0] & USB_CHANGED) { /* usb status changed */
-        if (data[0] & USB_STATUS) {
+    if (enrd0 & USB_CHANGED) { /* usb status changed */
+        if (enrd0 & USB_STATUS) {
             IFDEBUG(int_usb_insert++);
             usb_insert_int();
         } else {
@@ -454,6 +464,16 @@ static void ascodec_read_cb(unsigned const char *data, unsigned int len)
             usb_remove_int();
         }
     }
+}
+
+#if CONFIG_CPU == AS3525
+static void ascodec_read_cb(unsigned const char *data, unsigned int len)
+{
+    if (len != 3) /* some error happened? */
+        return;
+
+    cache_enrd0(data[0]);
+
     if (data[2] & IRQ_RTC) { /* rtc irq */
         /*
          * Can be configured for once per second or once per minute,
@@ -468,22 +488,40 @@ static void ascodec_read_cb(unsigned const char *data, unsigned int len)
     VIC_INT_ENABLE = INTERRUPT_AUDIO;
 }
 
+#endif /* CONFIG_CPU == AS3525 */
+
 void ascodec_wait_adc_finished(void)
 {
+#if CONFIG_CPU == AS3525
     wakeup_wait(&adc_wkup, TIMEOUT_BLOCK);
+#else
+    /* no interrupts, busy wait
+     * XXX: make sure this is the only reader of IRQ_ENRD2
+     */
+    while(!(ascodec_read(AS3514_IRQ_ENRD2) & IRQ_ADC))
+        yield();
+#endif
 }
-#endif /* CONFIG_CPU == AS3525 */
-
 
-void ascodec_enable_endofch_irq(void)
+#ifdef CONFIG_CHARGING
+bool ascodec_endofch(void)
 {
-    ascodec_write(AS3514_IRQ_ENRD0, ascodec_enrd0_shadow | CHG_ENDOFCH);
+#if CONFIG_CPU != AS3525
+    cache_enrd0(ascodec_read(AS3514_IRQ_ENRD0));
+#endif
+    bool ret = ascodec_enrd0_shadow & CHG_ENDOFCH;
+    ascodec_enrd0_shadow &= ~CHG_ENDOFCH; // clear interrupt
+    return ret;
 }
 
-void ascodec_disable_endofch_irq(void)
+bool ascodec_chg_status(void)
 {
-    ascodec_write(AS3514_IRQ_ENRD0, ascodec_enrd0_shadow & ~CHG_ENDOFCH);
+#if CONFIG_CPU != AS3525
+    cache_enrd0(ascodec_read(AS3514_IRQ_ENRD0));
+#endif
+    return ascodec_enrd0_shadow & CHG_STATUS;
 }
+#endif /* CONFIG_CHARGING */
 
 /*
  * NOTE:
diff --git a/firmware/target/arm/as3525/ascodec-target.h b/firmware/target/arm/as3525/ascodec-target.h
index 37947541c2..8ce9a428d3 100644
--- a/firmware/target/arm/as3525/ascodec-target.h
+++ b/firmware/target/arm/as3525/ascodec-target.h
@@ -52,7 +52,7 @@
 /*
  * How many bytes we using in struct ascodec_request for the data buffer.
  * 4 fits the alignment best right now.
- * We don't actually use more than 2 at the moment (in adc_read).
+ * We don't actually use more than 3 at the moment (when reading interrupts)
  * Upper limit would be 255 since DACNT is 8 bits!
  */
 #define ASCODEC_REQ_MAXLEN 4
@@ -74,19 +74,6 @@ void ascodec_init(void);
 
 int ascodec_write(unsigned int index, unsigned int value);
 
-#if CONFIG_CPU == AS3525v2
-static inline void ascodec_write_pmu(unsigned int index, unsigned int subreg,
-                                     unsigned int value)
-{
-    /* we disable interrupts to make sure no operation happen on the i2c bus
-     * between selecting the sub register and writing to it */
-    int oldstatus = disable_irq_save();
-    ascodec_write(AS3543_PMU_ENABLE, 8|subreg);
-    ascodec_write(index, value);
-    restore_irq(oldstatus);
-}
-#endif
-
 int ascodec_read(unsigned int index);
 
 int ascodec_readbytes(unsigned int index, unsigned int len, unsigned char *data);
@@ -119,18 +106,55 @@ void ascodec_lock(void);
 
 void ascodec_unlock(void);
 
-#if CONFIG_CPU == AS3525
 void ascodec_wait_adc_finished(void);
-#else
-static inline void ascodec_wait_adc_finished(void)
+
+static inline void ascodec_monitor_endofch(void) {} /* already enabled */
+
+bool ascodec_endofch(void);
+
+bool ascodec_chg_status(void);
+
+#if CONFIG_CPU == AS3525v2
+static inline void ascodec_write_pmu(unsigned int index, unsigned int subreg,
+                                     unsigned int value)
+{
+    /* we disable interrupts to make sure no operation happen on the i2c bus
+     * between selecting the sub register and writing to it */
+    int oldstatus = disable_irq_save();
+    ascodec_write(AS3543_PMU_ENABLE, 8|subreg);
+    ascodec_write(index, value);
+    restore_irq(oldstatus);
+}
+
+static inline int ascodec_read_pmu(unsigned int index, unsigned int subreg)
 {
-    /* FIXME: Doesn't work yet on AS3525v2 */
+    /* we disable interrupts to make sure no operation happen on the i2c bus
+     * between selecting the sub register and reading it */
+    int oldstatus = disable_irq_save();
+    ascodec_write(AS3543_PMU_ENABLE, 8|subreg);
+    int ret = ascodec_read(index);
+    restore_irq(oldstatus);
+    return ret;
 }
-#endif
+#endif /* CONFIG_CPU == AS3525v2 */
 
-void ascodec_enable_endofch_irq(void);
+static inline void ascodec_write_charger(int value)
+{
+#if CONFIG_CPU == AS3525
+    ascodec_write(AS3514_CHARGER, value);
+#else
+    ascodec_write_pmu(AS3543_CHARGER, 1, value);
+#endif
+}
 
-void ascodec_disable_endofch_irq(void);
+static inline int ascodec_read_charger(void)
+{
+#if CONFIG_CPU == AS3525
+    return ascodec_read(AS3514_CHARGER);
+#else
+    return ascodec_read_pmu(AS3543_CHARGER, 1);
+#endif
+}
 
 #endif /* !SIMULATOR */
 
diff --git a/firmware/target/arm/as3525/power-as3525.c b/firmware/target/arm/as3525/power-as3525.c
index 3570d7c75a..7b93dd1cd1 100644
--- a/firmware/target/arm/as3525/power-as3525.c
+++ b/firmware/target/arm/as3525/power-as3525.c
@@ -41,7 +41,7 @@ void power_init(void)
 #if CONFIG_CHARGING
 unsigned int power_input_status(void)
 {
-    return (ascodec_read(AS3514_IRQ_ENRD0) & (1<<5)) ?
+    return ascodec_chg_status() ?
         POWER_INPUT_MAIN_CHARGER : POWER_INPUT_NONE;
 
     /* TODO: Handle USB and other sources properly */
diff --git a/firmware/target/arm/as3525/usb-as3525.c b/firmware/target/arm/as3525/usb-as3525.c
index 74bfc17364..be62752033 100644
--- a/firmware/target/arm/as3525/usb-as3525.c
+++ b/firmware/target/arm/as3525/usb-as3525.c
@@ -29,13 +29,7 @@
 #include "power.h"
 #include "as3525.h"
 
-#if CONFIG_CPU == AS3525
 static int usb_status = USB_EXTRACTED;
-#else
-#if defined(SANSA_CLIPV2)
-#define USB_DETECT_PIN 6
-#endif
-#endif
 
 void usb_enable(bool on)
 {
@@ -51,12 +45,8 @@ void usb_enable(bool on)
 
 void usb_init_device(void)
 {
-#ifdef USB_DETECT_PIN
-    GPIOA_DIR &= ~(1 << USB_DETECT_PIN); /* set as input */
-#endif
 }
 
-#if CONFIG_CPU == AS3525
 void usb_insert_int(void)
 {
     usb_status = USB_INSERTED;
@@ -71,14 +61,3 @@ int usb_detect(void)
 {
     return usb_status;
 }
-#else
-int usb_detect(void)
-{
-#ifdef USB_DETECT_PIN
-    if (GPIOA_PIN( USB_DETECT_PIN ))
-        return USB_INSERTED;
-    else
-#endif
-        return USB_EXTRACTED;
-}
-#endif
diff --git a/firmware/target/arm/as3525/usb-target.h b/firmware/target/arm/as3525/usb-target.h
index 4c54dc182d..6df6d7c1d5 100644
--- a/firmware/target/arm/as3525/usb-target.h
+++ b/firmware/target/arm/as3525/usb-target.h
@@ -23,9 +23,7 @@
 
 void usb_init_device(void);
 int usb_detect(void);
-#if CONFIG_CPU == AS3525
 void usb_insert_int(void);
 void usb_remove_int(void);
-#endif /* CONFIG_CPU == AS3525 */
 
 #endif /* USB_TARGET_H */
diff --git a/firmware/target/arm/ascodec-target.h b/firmware/target/arm/ascodec-target.h
index c87d869ebb..68d9905a6b 100644
--- a/firmware/target/arm/ascodec-target.h
+++ b/firmware/target/arm/ascodec-target.h
@@ -59,14 +59,19 @@ static inline void ascodec_unlock(void)
     i2c_unlock();
 }
 
-static inline void ascodec_enable_endofch_irq(void)
+static inline bool ascodec_chg_status(void)
 {
-    ascodec_write(AS3514_IRQ_ENRD0, IRQ_ENDOFCH);
+    return ascodec_read(AS3514_IRQ_ENRD0) & CHG_STATUS;
+}
+
+static inline bool ascodec_endofch(void)
+{
+    return ascodec_read(AS3514_IRQ_ENRD0) & CHG_ENDOFCH;
 }
 
-static inline void ascodec_disable_endofch_irq(void)
+static inline void ascodec_monitor_endofch(void)
 {
-    ascodec_write(AS3514_IRQ_ENRD0, 0);
+    ascodec_write(AS3514_IRQ_ENRD0, IRQ_ENDOFCH);
 }
 
 static inline void ascodec_wait_adc_finished(void)
@@ -81,6 +86,16 @@ static inline void ascodec_wait_adc_finished(void)
      */
 }
 
+static inline void ascodec_write_charger(int value)
+{
+    ascodec_write(AS3514_CHARGER, value);
+}
+
+static inline int ascodec_read_charger(void)
+{
+    return ascodec_read(AS3514_CHARGER);
+}
+
 extern void ascodec_suppressor_on(bool on);
 
 #endif /* CPU_PP */
diff --git a/firmware/target/arm/powermgmt-ascodec.c b/firmware/target/arm/powermgmt-ascodec.c
index b463486346..e50367fe93 100644
--- a/firmware/target/arm/powermgmt-ascodec.c
+++ b/firmware/target/arm/powermgmt-ascodec.c
@@ -94,9 +94,7 @@ static void battery_voltage_sync(void)
 /* Disable charger and minimize all settings. Reset timers, etc. */
 static void disable_charger(void)
 {
-    ascodec_disable_endofch_irq();
-    ascodec_write(AS3514_CHARGER,
-                  TMPSUP_OFF | CHG_I_50MA | CHG_V_3_90V | CHG_OFF);
+    ascodec_write_charger(TMPSUP_OFF | CHG_I_50MA | CHG_V_3_90V | CHG_OFF);
 
     if (charge_state > DISCHARGING)
         charge_state = DISCHARGING; /* Not an error state already */
@@ -108,14 +106,13 @@ static void disable_charger(void)
 /* Enable charger with specified settings. Start timers, etc. */
 static void enable_charger(void)
 {
-    ascodec_write(AS3514_CHARGER, BATT_CHG_I | BATT_CHG_V);
-    /* Watch for end of charge. Temperature supervision is handled in
-     * hardware. Charger status can be read and has no interrupt enable. */
-    ascodec_enable_endofch_irq();
+    ascodec_write_charger(BATT_CHG_I | BATT_CHG_V);
 
     sleep(HZ/10); /* Allow charger turn-on time (it could be gradual). */
 
-    ascodec_disable_endofch_irq();
+    /* acknowledge first end of charging interrupt, it seems to happen both
+     * at charger plug and charger unplug */
+    ascodec_endofch();
 
     charge_state = CHARGING;
     charger_total_timer = CHARGER_TOTAL_TIMER;
@@ -125,9 +122,8 @@ static void enable_charger(void)
 void powermgmt_init_target(void)
 {
     /* Everything CHARGER, OFF! */
-    ascodec_disable_endofch_irq();
-    ascodec_write(AS3514_CHARGER,
-                  TMPSUP_OFF | CHG_I_50MA | CHG_V_3_90V | CHG_OFF);
+    ascodec_monitor_endofch();
+    ascodec_write_charger(TMPSUP_OFF | CHG_I_50MA | CHG_V_3_90V | CHG_OFF);
 }
 
 static inline void charger_plugged(void)
@@ -148,7 +144,7 @@ static inline void charger_control(void)
         if (BATT_FULL_VOLTAGE == thresh)
         {
             /* Wait for CHG_status to be indicated. */
-            if ((ascodec_read(AS3514_IRQ_ENRD0) & CHG_STATUS) == 0)
+            if (!ascodec_chg_status())
                 break;
 
             batt_threshold = BATT_VAUTO_RECHARGE;
@@ -163,7 +159,7 @@ static inline void charger_control(void)
 
     case CHARGING:
     {
-        if ((ascodec_read(AS3514_IRQ_ENRD0) & CHG_ENDOFCH) == 0)
+        if (!ascodec_endofch())
         {
             if (--charger_total_timer > 0)
                 break;