meg-fx: It's important to make sure certain interrupt-related registers have bits changed atomically.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@16894 a1c6a512-1295-4272-9138-f99709370657

firmware/target/arm/s3c2440/gigabeat-fx/adc-meg-fx.c

@@ -17,6 +17,7 @@
  *
  ****************************************************************************/
 #include "cpu.h"
+#include "system.h"
 #include "adc-target.h"
 #include "kernel.h"
 
@@ -35,7 +36,7 @@ void adc_init(void)
     int i;
 
     /* Turn on the ADC PCLK */
-    CLKCON |= (1<<15);
+    s3c_regset(&CLKCON, 1<<15);
 
     /* Set channel 0, normal mode, disable "start by read" */
     ADCCON &= ~(0x3F);

firmware/target/arm/s3c2440/gigabeat-fx/i2c-meg-fx.c

@@ -41,7 +41,7 @@ void i2c_write(int addr, const unsigned char *buf, int count)
     mutex_lock(&i2c_mtx);
 
     /* Turn on I2C clock */
-    CLKCON |= (1 << 16);
+    s3c_regset(&CLKCON, 1 << 16);
 
     /* Set mode to master transmitter and enable lines */
     IICSTAT = I2C_MODE_MASTER | I2C_MODE_TX | I2C_RXTX_ENB;
@@ -74,7 +74,7 @@ void i2c_write(int addr, const unsigned char *buf, int count)
     IICSTAT = 0;
 
     /* Turn off I2C clock */
-    CLKCON &= ~(1 << 16);
+    s3c_regclr(&CLKCON, 1 << 16);
 
     mutex_unlock(&i2c_mtx);
 }
@@ -90,11 +90,11 @@ void i2c_init(void)
     INTPND = IIC_MASK;
 
     /* Enable i2c interrupt in controller */
-    INTMOD &= ~IIC_MASK;
+    s3c_regclr(&INTMOD, IIC_MASK);
-    INTMSK &= ~IIC_MASK;
+    s3c_regclr(&INTMSK, IIC_MASK);
 
     /* Turn on I2C clock */
-    CLKCON |= (1 << 16);
+    s3c_regset(&CLKCON, 1 << 16);
 
     /* Set GPE15 (IICSDA) and GPE14 (IICSCL) to IIC */
     GPECON = (GPECON & ~((3 << 30) | (3 << 28))) |
@@ -108,7 +108,7 @@ void i2c_init(void)
     IICLC = (0 << 0);
 
     /* Turn off I2C clock */
-    CLKCON &= ~(1 << 16);
+    s3c_regclr(&CLKCON, 1 << 16);
 }
 
 void IIC(void)

firmware/target/arm/s3c2440/gigabeat-fx/lcd-meg-fx.c

@@ -1,4 +1,5 @@
 #include "config.h"
+#include "system.h"
 #include "cpu.h"
 #include "string.h"
 #include "lcd.h"
@@ -81,7 +82,7 @@ void SPI_Send_Bytes(const unsigned char *array, int count)
 
 void Setup_LCD_SPI(void)
 {
-    CLKCON|=0x40000;
+    s3c_regset(&CLKCON, 0x40000);
     SPI_LCD_CS(false);
     SPCON0=0x3E;
     SPPRE0=24;
@@ -147,7 +148,7 @@ void lcd_init_device(void)
     lcd_poweroff = false;
 #endif
 
-    CLKCON  |= 0x20;       /* enable LCD clock */
+    s3c_regset(&CLKCON, 0x20);       /* enable LCD clock */
 
     Setup_LCD_SPI();
 
@@ -204,7 +205,7 @@ void lcd_init_device(void)
     SPI_Send_Bytes(initbuf, sizeof(initbuf));
     SPI_LCD_CS(false);
 
-    CLKCON  &= ~0x40000;    /* disable SPI clock */  
+    s3c_regclr(&CLKCON, 0x40000);    /* disable SPI clock */  
 }
 
 /* Update a fraction of the display. */

firmware/target/arm/s3c2440/gigabeat-fx/pcm-meg-fx.c

@@ -38,7 +38,7 @@ static struct
 } dma_play_lock =
 {
     .locked = 0,
-    .state  = (0<<19)
+    .state  = 0,
 };
 
 /* Last samplerate set by pcm_set_frequency */
@@ -71,22 +71,18 @@ void pcm_apply_settings(void)
     restore_fiq(status);
 }
 
-/* For the locks, DMA interrupt must be disabled because the handler
+/* Mask the DMA interrupt */
-   manipulates INTMSK and the operation is not atomic */
 void pcm_play_lock(void)
 {
-    int status = disable_fiq_save();
     if (++dma_play_lock.locked == 1)
-        INTMSK |= (1<<19); /* Mask the DMA interrupt */
+        s3c_regset(&INTMSK, DMA2_MASK);
-    restore_fiq(status);
 }
 
+/* Unmask the DMA interrupt if enabled */
 void pcm_play_unlock(void)
 {
-    int status = disable_fiq_save();
     if (--dma_play_lock.locked == 0)
-        INTMSK &= ~dma_play_lock.state; /* Unmask the DMA interrupt if enabled */
+        s3c_regclr(&INTMSK, dma_play_lock.state);
-    restore_fiq(status);
 }
 
 void pcm_play_dma_init(void)
@@ -110,11 +106,11 @@ void pcm_play_dma_init(void)
     /* Do not service DMA requests, yet */
 
     /* clear any pending int and mask it */
-    INTMSK |= (1<<19);
+    s3c_regset(&INTMSK, DMA2_MASK);
-    SRCPND = (1<<19);
+    SRCPND = DMA2_MASK;
 
     /* connect to FIQ */
-    INTMOD |= (1<<19);
+    s3c_regset(&INTMOD, DMA2_MASK);
 }
 
 void pcm_postinit(void)
@@ -127,7 +123,7 @@ void pcm_postinit(void)
 static void play_start_pcm(void)
 {
     /* clear pending DMA interrupt */
-    SRCPND = (1<<19);
+    SRCPND = DMA2_MASK;
 
     _pcm_apply_settings();
 
@@ -135,7 +131,7 @@ static void play_start_pcm(void)
     clean_dcache_range((void*)DISRC2, (DCON2 & 0xFFFFF) * 2);
 
     /* unmask DMA interrupt when unlocking */
-    dma_play_lock.state = (1<<19);
+    dma_play_lock.state = DMA2_MASK;
 
     /* turn on the request */
     IISCON |= (1<<5);
@@ -154,7 +150,7 @@ static void play_start_pcm(void)
 static void play_stop_pcm(void)
 {
     /* Mask DMA interrupt */
-    INTMSK |= (1<<19);
+    s3c_regset(&INTMSK, DMA2_MASK);
 
     /* De-Activate the DMA channel */
     DMASKTRIG2 = 0x4;
@@ -182,7 +178,7 @@ static void play_stop_pcm(void)
 void pcm_play_dma_start(const void *addr, size_t size)
 {
     /* Enable the IIS clock */
-    CLKCON |= (1<<17);
+    s3c_regset(&CLKCON, 1<<17);
 
     /* stop any DMA in progress - idle IIS */
     play_stop_pcm();
@@ -217,7 +213,7 @@ void pcm_play_dma_stop(void)
     play_stop_pcm();
 
     /* Disconnect the IIS clock */
-    CLKCON &= ~(1<<17);
+    s3c_regclr(&CLKCON, 1<<17);
 }
 
 void pcm_play_dma_pause(bool pause)
@@ -245,7 +241,7 @@ void fiq_handler(void)
     register pcm_more_callback_type get_more;   /* No stack for this */
 
     /* clear any pending interrupt */
-    SRCPND = (1<<19);
+    SRCPND = DMA2_MASK;
 
     /* Buffer empty.  Try to get more. */
     get_more = pcm_callback_for_more;

firmware/target/arm/s3c2440/gigabeat-fx/system-meg-fx.c

@@ -104,6 +104,24 @@ void memory_init(void) {
     enable_mmu();
 }
 
+void s3c_regmod(volatile int *reg, unsigned int set, unsigned int clr)
+{
+    int oldstatus = disable_interrupt_save(IRQ_FIQ_STATUS);
+    unsigned int val = *reg;
+    *reg = (val | set) & ~clr;
+    restore_interrupt(oldstatus);
+}
+
+void s3c_regset(volatile int *reg, unsigned int mask)
+{
+    s3c_regmod(reg, mask, 0);
+}
+
+void s3c_regclr(volatile int *reg, unsigned int mask)
+{
+    s3c_regmod(reg, 0, mask);
+}
+
 void system_init(void)
 {
     /* Disable interrupts and set all to IRQ mode */

firmware/target/arm/s3c2440/gigabeat-fx/system-target.h

@@ -26,6 +26,15 @@
 #define CPUFREQ_NORMAL  98784000
 #define CPUFREQ_MAX    296352000
 
+/* Functions to set and clear regiser bits atomically */
+
+/* Set and clear register bits */
+void s3c_regmod(volatile int *reg, unsigned int set, unsigned int clr);
+/* Set register bits */
+void s3c_regset(volatile int *reg, unsigned int mask);
+/* Clear register bits */
+void s3c_regclr(volatile int *reg, unsigned int mask);
+
 #define HAVE_INVALIDATE_ICACHE
 static inline void invalidate_icache(void)
 {

firmware/target/arm/s3c2440/gigabeat-fx/timer-meg-fx.c

@@ -89,7 +89,7 @@ bool __timer_register(void)
 {
     bool retval = true;
 
-    int oldstatus = set_interrupt_status(IRQ_FIQ_DISABLED, IRQ_FIQ_STATUS);
+    int oldstatus = disable_interrupt_save(IRQ_FIQ_STATUS);
 
     stop_timer();
 
@@ -115,14 +115,14 @@ bool __timer_register(void)
         retval = false;
     }
 
-    set_interrupt_status(oldstatus, IRQ_FIQ_STATUS);
+    restore_interrupt(oldstatus);
 
     return retval;
 }
 
 void __timer_unregister(void)
 {
-    int oldstatus = set_interrupt_status(IRQ_FIQ_DISABLED, IRQ_FIQ_STATUS);
+    int oldstatus = disable_interrupt_save(IRQ_FIQ_STATUS);
     stop_timer();
-    set_interrupt_status(oldstatus, IRQ_FIQ_STATUS);
+    restore_interrupt(oldstatus);
 }