Merged from external project:

	**********
	r25976 | lottaviano | 2009-06-15 09:38:55 +0200 (lun, 15 giu 2009) | 1 line

	Initial support for i2s in at91sam7.
	**********

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@2731 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/bertos/drv/i2s.c b/bertos/drv/i2s.c
new file mode 100644 (file)
index 0000000..d95040f
--- /dev/null
+++ b/bertos/drv/i2s.c
@@ -0,0 +1,190 @@
+#include <drv/i2s.h>
+#include <cfg/macros.h>
+#include <cfg/log.h>
+#include <io/arm.h>
+
+static uint8_t play_buf1[CONFIG_PLAY_BUF_LEN];
+static uint8_t play_buf2[CONFIG_PLAY_BUF_LEN];
+
+/* |x|x|CONT|SECOND|FIRST|IS_PLAYING|CUR_BUF| */
+/* |7|6| 5  |  4   |  3  |     2    | 1   0 | */
+static uint8_t status;
+#define CURRENT_BUF     0x03
+#define IS_PLAYING       2
+#define FIRST_BUF_FULL   3
+#define SECOND_BUF_FULL  4
+#define CONTINUE_PLAY    5
+
+INLINE bool is_buffer_full(int bv)
+{
+       return status & BV(bv);
+}
+
+uint8_t *i2s_getBuffer(unsigned buf_num)
+{
+       kprintf("getBuffer start\n");
+       if (status & BV(IS_PLAYING))
+               return 0;
+
+       if ((buf_num == I2S_FIRST_BUF) && !is_buffer_full(FIRST_BUF_FULL))
+       {
+               status |= BV(FIRST_BUF_FULL);
+               kprintf("status [0x%02X]\n", status);
+               return play_buf1;
+       }
+       else if ((buf_num == I2S_SECOND_BUF) && !is_buffer_full(SECOND_BUF_FULL))
+       {
+               status |= BV(SECOND_BUF_FULL);
+               kprintf("status [0x%02X]\n", status);
+               return play_buf2;
+       }
+       else
+               return 0;
+}
+
+uint8_t *i2s_getFreeBuffer(void)
+{
+       if (!(status & BV(IS_PLAYING)))
+               return 0;
+
+       // disable irq
+       // ...
+       // set continue flag
+       // ...
+       // set buf_full flag
+       // ...
+       // enable irq
+       // ...
+       // return the buffer
+
+       if ((status & CURRENT_BUF) == I2S_FIRST_BUF && !is_buffer_full(SECOND_BUF_FULL))
+               return play_buf2;
+       else if ((status & CURRENT_BUF) == I2S_SECOND_BUF && !is_buffer_full(FIRST_BUF_FULL))
+               return play_buf1;
+       else
+               return 0;
+}
+
+INLINE void setCurrentBuffer(int buffer)
+{
+       status &= ~CURRENT_BUF;
+       status |= CURRENT_BUF & buffer;
+}
+
+// code irq callback
+static void i2s_dma_tx_irq_handler(void) __attribute__ ((interrupt));
+static void i2s_dma_tx_irq_handler(void)
+{
+       /*
+       if (status & BV(CONTINUE_PLAY))
+       {
+               kprintf("irq\n");
+               if ((status & CURRENT_BUF) == I2S_FIRST_BUF)
+               {
+                       SSC_PTCR = BV(PDC_TXTDIS);
+                       SSC_TPR = (reg32_t)play_buf2;
+                       SSC_TCR = CONFIG_PLAY_BUF_LEN;
+                       SSC_PTCR = BV(PDC_TXTEN);
+
+                       setCurrentBuffer(I2S_SECOND_BUF);
+                       status &= ~BV(FIRST_BUF_FULL);
+                       status &= ~BV(CONTINUE_PLAY);
+               }
+               // TODO: refactor.
+               else
+               {
+                       SSC_PTCR = BV(PDC_TXTDIS);
+                       SSC_TPR = (reg32_t)play_buf1;
+                       SSC_TCR = CONFIG_PLAY_BUF_LEN;
+                       SSC_PTCR = BV(PDC_TXTEN);
+
+                       setCurrentBuffer(I2S_FIRST_BUF);
+                       status &= ~BV(SECOND_BUF_FULL);
+                       status &= ~BV(CONTINUE_PLAY);
+               }
+       }
+       */
+       AIC_EOICR = 0;
+}
+
+bool i2s_start(void)
+{
+       SSC_PTCR = BV(PDC_TXTDIS);
+       SSC_TPR = (reg32_t)play_buf1;
+       SSC_TCR = CONFIG_PLAY_BUF_LEN / 2;
+       SSC_PTCR = BV(PDC_TXTEN);
+       ASSERT(SSC_PTSR & BV(PDC_TXTEN));
+       /*
+       kprintf("i2s_start start\n");
+       if (status & (BV(FIRST_BUF_FULL) | BV(SECOND_BUF_FULL)))
+       {
+               setCurrentBuffer(I2S_FIRST_BUF);
+               SSC_PTCR = BV(PDC_TXTDIS);
+               SSC_TPR = (reg32_t)play_buf1;
+               SSC_TCR = CONFIG_PLAY_BUF_LEN;
+
+               status |= BV(IS_PLAYING);
+               status |= BV(CONTINUE_PLAY);
+               kprintf("start: status [0x%02X]\n", status);
+               SSC_PTCR = BV(PDC_TXTEN);
+
+               return true;
+       }
+       else
+       {
+               kprintf("start: buffers are not full\n");
+               return false;
+       }
+       */
+       return true;
+}
+
+#define MCK_DIV 16
+#define DELAY ((0 << SSC_STTDLY_SHIFT) & SSC_STTDLY)
+#define PERIOD ((7 << (SSC_PERIOD_SHIFT)) & SSC_PERIOD)
+/* wtf?? it seems that no 16 won't be sent with MSB first...*/
+#define DATALEN (15 & SSC_DATLEN)
+#define DATNB ((1 << SSC_DATNB_SHIFT) & SSC_DATNB)
+#define FSLEN ((1 << SSC_FSLEN_SHIFT) & SSC_FSLEN)
+
+#define SSC_DMA_IRQ_PRIORITY 5
+
+void i2s_init(void)
+{
+       PIOA_PDR = BV(SPI1_SPCK) | BV(SPI1_MOSI) | BV(SPI1_NPCS0);
+       /* reset device */
+       SSC_CR = BV(SSC_SWRST);
+
+       SSC_CMR = MCK_DIV & SSC_DIV;
+       SSC_TCMR = SSC_CKS_DIV | SSC_CKO_TRAN | SSC_CKG_NONE | SSC_START_CONT | DELAY | PERIOD;
+       SSC_TFMR = DATALEN | FSLEN | SSC_MSBF | SSC_FSOS_POSITIVE;
+
+       /* Disable all irqs */
+       SSC_IDR = 0xFFFFFFFF;
+       /* Set the vector. */
+       AIC_SVR(SSC_ID) = i2s_dma_tx_irq_handler;
+       /* Initialize to edge triggered with defined priority. */
+       AIC_SMR(SPI0_ID) = AIC_SRCTYPE_INT_EDGE_TRIGGERED | SSC_DMA_IRQ_PRIORITY;
+       /* Enable the SSC IRQ */
+       AIC_IDCR = BV(SSC_ID);
+       /* Enable interrupt on tx buffer empty */
+       SSC_IER = BV(SSC_ENDTX);
+
+       /* enable i2s */
+       PMC_PCER = BV(SSC_ID);
+
+       /* enable output */
+       SSC_CR = BV(SSC_TXEN);
+
+       /* set current buffer to 1 */
+       status = 0x01;
+       for (int i = 0; i < CONFIG_PLAY_BUF_LEN; ++i)
+       {
+               //uint32_t tmp = 0x5555;
+               //uint32_t tmp2 = 0x9999;
+               play_buf1[i] = (uint8_t)i;
+               //play_buf1[i+4] = tmp2;
+       }
+}
+
+

diff --git a/bertos/drv/i2s.h b/bertos/drv/i2s.h
new file mode 100644 (file)
index 0000000..e010470
--- /dev/null
+++ b/bertos/drv/i2s.h
@@ -0,0 +1,22 @@
+#ifndef I2S_H
+#define I2S_H
+
+#include <cfg/compiler.h>
+
+#define CONFIG_PLAY_BUF_LEN 16
+#define I2S_FIRST_BUF  1
+#define I2S_SECOND_BUF 2
+
+void i2s_init(void);
+
+/* Low level call that returns one of the two buffers or NULL if none is available */
+uint8_t *i2s_getBuffer(unsigned buf_num);
+
+/* Returns a buffer that will be played after the current one. Blocking call */
+uint8_t *i2s_getFreeBuffer(void);
+
+/* Starts playing from I2S_FIRST_BUFFER. You must have filled both buffers before calling this
+ * function. Does nothing if already playing. */
+bool i2s_start(void);
+
+#endif /* I2S_H */