Improve ipod i2c driver somewhat by at least taking advantage of the in-device addressing in the pcf50605, also switch to a 10bit resistive divider for the ipod battery reading, this is easily configurable if it needs changing, or even to become a user/runtime setting

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@8980 a1c6a512-1295-4272-9138-f99709370657

firmware/common/timefuncs.c

@@ -47,12 +47,13 @@ struct tm *get_time(void)
 {
 #ifndef SIMULATOR
 #ifdef CONFIG_RTC
-    static long last_tick = 0;
+    static long timeout = 0;
 
-    /* Don't read the RTC more than 4 times per second */
-    if (last_tick + HZ < current_tick) {
+    /* Don't read the RTC more than once per second */
+    if (current_tick > timeout) {
         char rtcbuf[7];
-        last_tick = HZ * (current_tick / HZ);
+        /* Once per second, 1/10th of a second off */
+        timeout = HZ * (current_tick / HZ + 1) + HZ / 5;
         rtc_read_datetime(rtcbuf);
 
         tm.tm_sec = ((rtcbuf[0] & 0x70) >> 4) * 10 + (rtcbuf[0] & 0x0f);

firmware/drivers/adc.c

@@ -286,60 +286,57 @@ void adc_init(void)
 #elif CONFIG_CPU == PP5020 || (CONFIG_CPU == PP5002)
 
 struct adc_struct {
-    long last_read;
-    unsigned short (*conversion)(unsigned short data);
+    long timeout;
+    void (*conversion)(unsigned short *data);
     short channelnum;
     unsigned short data;
 };
 
 static struct adc_struct adcdata[NUM_ADC_CHANNELS] IDATA_ATTR;
 
-/* This takes 10 bit ADC data from the subtractor circuit and scales it to
- * a 13 bit value corresponding to 0-5.4v, the resulting range is 13FB-17FA,
- * representing 3.1-5.4v */
-static unsigned short ten_bit_subtractor(unsigned short data) {
-    return (data<<2)+0x4FB;
-}
-
-static unsigned short _adc_scan(struct adc_struct *adc)
+static unsigned short _adc_read(struct adc_struct *adc)
 {
-    unsigned short data;
+    if (adc->timeout < current_tick) {
+        unsigned char data[2];
+        unsigned short value;
+        /* 5x per 2 seconds */
+        adc->timeout = current_tick + (HZ * 2 / 5);
 
-    /* ADCC1, 8 bit, start */
-    pcf50605_write(0x2f, 0x80 | (adc->channelnum << 1) | 0x1);
-    data = pcf50605_read(0x30); /* ADCS1 */
+        /* ADCC1, 10 bit, start */
+        pcf50605_write(0x2f, (adc->channelnum << 1) | 0x1);
+        pcf50605_read_multiple(0x30, data, 2); /* ADCS1, ADCS2 */
+        value   = data[0];
+        value <<= 2;
+        value  |= data[1] & 0x3;
 
-    if (adc->conversion) {
-        data = adc->conversion(data);
-    }
-    adc->data = data;
-    return data;
-}
-
-/* Force an ADC scan _now_ */
-unsigned short adc_scan(int channel) {
-    return _adc_scan(&adcdata[channel]);
-}
-
-/* Retrieve the ADC value, only does a scan once per second or less */
-unsigned short adc_read(int channel)
-{
-    struct adc_struct *adc = &adcdata[channel];
-    if (adc->last_read + HZ < current_tick) {
-        adc->last_read = current_tick;
-        return _adc_scan(adc);
+        if (adc->conversion) {
+            adc->conversion(&value);
+        }
+        adc->data = value;
+        return value;
     } else {
         return adc->data;
     }
 }
 
+/* Force an ADC scan _now_ */
+unsigned short adc_scan(int channel) {
+    struct adc_struct *adc = &adcdata[channel];
+    adc->timeout = 0;
+    return _adc_read(adc);
+}
+
+/* Retrieve the ADC value, only does a scan periodically */
+unsigned short adc_read(int channel) {
+    return _adc_read(&adcdata[channel]);
+}
+
 void adc_init(void)
 {
     struct adc_struct *adc_battery = &adcdata[ADC_BATTERY];
-    adc_battery->channelnum = 0x3; /* ADCVIN1, subtractor */
-    adc_battery->conversion = ten_bit_subtractor;
-    adc_battery->last_read = current_tick;
-    _adc_scan(adc_battery);
+    adc_battery->channelnum = 0x2; /* ADCVIN1, resistive divider */
+    adc_battery->timeout = 0;
+    _adc_read(adc_battery);
 }
 
 #elif CONFIG_CPU == PNX0101

firmware/drivers/i2c-pp5002.c

@@ -136,6 +136,16 @@ int ipod_i2c_send_byte(unsigned int addr, int data0)
     return ipod_i2c_send_bytes(addr, 1, data);
 }
 
+int i2c_readbytes(unsigned int dev_addr, int addr, int len, unsigned char *data) {
+    unsigned int temp;
+    int i;
+    ipod_i2c_send_byte(dev_addr, addr);
+    for (i = 0; i < len; i++) {
+        ipod_i2c_read_byte(dev_addr, &temp);
+        data[i] = temp;
+    }
+    return i;
+}
 
 int i2c_readbyte(unsigned int dev_addr, int addr)
 {

firmware/drivers/i2c-pp5020.c

@@ -63,7 +63,6 @@ static int ipod_i2c_wait_not_busy(void)
     return -1;
 }
 
-
 static int ipod_i2c_read_byte(unsigned int addr, unsigned int *data)
 {
     if (ipod_i2c_wait_not_busy() < 0)
@@ -72,6 +71,7 @@ static int ipod_i2c_read_byte(unsigned int addr, unsigned int *data)
     }
 
     {
+        unsigned int byte;
         int old_irq_level = set_irq_level(HIGHEST_IRQ_LEVEL);
 
         /* clear top 15 bits, left shift 1, or in 0x1 for a read */
@@ -81,15 +81,18 @@ static int ipod_i2c_read_byte(unsigned int addr, unsigned int *data)
 
         outb(inb(IPOD_I2C_CTRL) | IPOD_I2C_SEND, IPOD_I2C_CTRL);
 
-        if (data)
+        set_irq_level(old_irq_level);
+        if (ipod_i2c_wait_not_busy() < 0)
         {
-            if (ipod_i2c_wait_not_busy() < 0)
-            {
-                set_irq_level(old_irq_level);
-                return -1;
-            }
-            *data = inb(IPOD_I2C_DATA0);
+            return -1;
         }
+        old_irq_level = set_irq_level(HIGHEST_IRQ_LEVEL);
+
+        byte = inb(IPOD_I2C_DATA0);
+
+        if (data)
+            *data = byte;
+
         set_irq_level(old_irq_level);
     }
 
@@ -148,6 +151,19 @@ static int ipod_i2c_send_byte(unsigned int addr, int data0)
 /* Public functions */
 static struct mutex i2c_mutex;
 
+int i2c_readbytes(unsigned int dev_addr, int addr, int len, unsigned char *data) {
+    unsigned int temp;
+    int i;
+    mutex_lock(&i2c_mutex);
+    ipod_i2c_send_byte(dev_addr, addr);
+    for (i = 0; i < len; i++) {
+        ipod_i2c_read_byte(dev_addr, &temp);
+        data[i] = temp;
+    }
+    mutex_unlock(&i2c_mutex);
+    return i;
+}
+
 int i2c_readbyte(unsigned int dev_addr, int addr)
 {
     int data;

firmware/drivers/pcf50605.c

@@ -23,6 +23,7 @@
  * KIND, either express or implied.
  *
  ****************************************************************************/
+#include "system.h"
 #include "config.h"
 #if CONFIG_I2C == I2C_PP5020
 #include "i2c-pp5020.h"
@@ -72,15 +73,8 @@ int pcf50605_read(int address)
 
 int pcf50605_read_multiple(int address, unsigned char* buf, int count)
 {
-    int i;
-
-    for (i=0;i<count;i++)
-    {
-        buf[i]=pcf50605_read(address);
-        address++;
-    }
-
-    return 0;
+    int read = i2c_readbytes(0x08, address, count, buf);
+    return read - count;
 }
 
 int pcf50605_write(int address, unsigned char val)

firmware/drivers/rtc.c

@@ -34,12 +34,12 @@
 void rtc_init(void)
 {
 }
+
 int rtc_read_datetime(unsigned char* buf)
 {
     return pcf50605_read_multiple(0x0a, buf, 7);
 }
 
-
 int rtc_write_datetime(unsigned char* buf)
 {
     int i;

firmware/export/i2c-pp5002.h

@@ -30,5 +30,6 @@
 void i2c_init(void);
 int i2c_readbyte(unsigned int dev_addr, int addr);
 int ipod_i2c_send(unsigned int addr, int data0, int data1);
+int i2c_readbytes(unsigned int dev_addr, int addr, int len, unsigned char *data);
 
 #endif

firmware/export/i2c-pp5020.h

@@ -30,5 +30,6 @@
 void i2c_init(void);
 int i2c_readbyte(unsigned int dev_addr, int addr);
 int ipod_i2c_send(unsigned int addr, int data0, int data1);
+int i2c_readbytes(unsigned int dev_addr, int addr, int len, unsigned char *data);
 
 #endif