82xx serial, smc: add configurable SMC Rx buffer len

This patch adds the configuration option CONFIG_SYS_SMC_RXBUFLEN.
With this option it is possible to allow the receive
buffer for the SMC on 82xx to be greater then 1. In case
CONFIG_SYS_SMC_RXBUFLEN == 1 this driver works as the
old version.

When defining CONFIG_SYS_SMC_RXBUFLEN also
CONFIG_SYS_MAXIDLE must be defined to setup the maximum
idle timeout for the SMC.

Signed-off-by: Heiko Schocher <hs@denx.de>

diff --git a/README b/README
index 522471cf781a55ed85e41e23832e5dfa6edf1aa4..fcadf3f0c65ad17246fbb428e1802cad5e707b0d 100644 (file)
--- a/README
+++ b/README
@@ -484,6 +484,14 @@ The following options need to be configured:
                CONFIG_SYS_BAUDRATE_TABLE, see below.
                CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
 
+- Console Rx buffer length
+               With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
+               the maximum receive buffer length for the SMC.
+               This option is actual only for 82xx possible.
+               If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
+               must be defined, to setup the maximum idle timeout for
+               the SMC.
+
 - Interrupt driven serial port input:
                CONFIG_SERIAL_SOFTWARE_FIFO
 

diff --git a/cpu/mpc8260/serial_smc.c b/cpu/mpc8260/serial_smc.c
index a6efa66895fcd9126b3a42a840bacf318d5381b7..794d6b31903de05147567456285d2cb5e49c0c16 100644 (file)
--- a/cpu/mpc8260/serial_smc.c
+++ b/cpu/mpc8260/serial_smc.c
@@ -64,6 +64,23 @@ DECLARE_GLOBAL_DATA_PTR;
 
 #endif
 
+#if !defined(CONFIG_SYS_SMC_RXBUFLEN)
+#define CONFIG_SYS_SMC_RXBUFLEN        1
+#define CONFIG_SYS_MAXIDLE     0
+#else
+#if !defined(CONFIG_SYS_MAXIDLE)
+#error "you must define CONFIG_SYS_MAXIDLE"
+#endif
+#endif
+
+typedef volatile struct serialbuffer {
+       cbd_t   rxbd;           /* Rx BD */
+       cbd_t   txbd;           /* Tx BD */
+       uint    rxindex;        /* index for next character to read */
+       volatile uchar  rxbuf[CONFIG_SYS_SMC_RXBUFLEN];/* rx buffers */
+       volatile uchar  txbuf;  /* tx buffers */
+} serialbuffer_t;
+
 /* map rs_table index to baud rate generator index */
 static unsigned char brg_map[] = {
        6,      /* BRG7 for SMC1 */
@@ -79,9 +96,9 @@ int serial_init (void)
        volatile immap_t *im = (immap_t *)CONFIG_SYS_IMMR;
        volatile smc_t *sp;
        volatile smc_uart_t *up;
-       volatile cbd_t *tbdf, *rbdf;
        volatile cpm8260_t *cp = &(im->im_cpm);
        uint    dpaddr;
+       volatile serialbuffer_t *rtx;
 
        /* initialize pointers to SMC */
 
@@ -99,17 +116,21 @@ int serial_init (void)
         * damm: allocating space after the two buffers for rx/tx data
         */
 
-       dpaddr = m8260_cpm_dpalloc((2 * sizeof (cbd_t)) + 2, 16);
+       /* allocate size of struct serialbuffer with bd rx/tx,
+        * buffer rx/tx and rx index
+        */
+       dpaddr = m8260_cpm_dpalloc((sizeof(serialbuffer_t)), 16);
+
+       rtx = (serialbuffer_t *)&im->im_dprambase[dpaddr];
 
        /* Set the physical address of the host memory buffers in
         * the buffer descriptors.
         */
-       rbdf = (cbd_t *)&im->im_dprambase[dpaddr];
-       rbdf->cbd_bufaddr = (uint) (rbdf+2);
-       rbdf->cbd_sc = 0;
-       tbdf = rbdf + 1;
-       tbdf->cbd_bufaddr = ((uint) (rbdf+2)) + 1;
-       tbdf->cbd_sc = 0;
+       rtx->rxbd.cbd_bufaddr = (uint) &rtx->rxbuf;
+       rtx->rxbd.cbd_sc      = 0;
+
+       rtx->txbd.cbd_bufaddr = (uint) &rtx->txbuf;
+       rtx->txbd.cbd_sc      = 0;
 
        /* Set up the uart parameters in the parameter ram.
        */
@@ -142,13 +163,13 @@ int serial_init (void)
 
        /* Make the first buffer the only buffer.
        */
-       tbdf->cbd_sc |= BD_SC_WRAP;
-       rbdf->cbd_sc |= BD_SC_EMPTY | BD_SC_WRAP;
+       rtx->txbd.cbd_sc |= BD_SC_WRAP;
+       rtx->rxbd.cbd_sc |= BD_SC_EMPTY | BD_SC_WRAP;
 
-       /* Single character receive.
-       */
-       up->smc_mrblr = 1;
-       up->smc_maxidl = 0;
+       /* single/multi character receive. */
+       up->smc_mrblr = CONFIG_SYS_SMC_RXBUFLEN;
+       up->smc_maxidl = CONFIG_SYS_MAXIDLE;
+       rtx->rxindex = 0;
 
        /* Initialize Tx/Rx parameters.
        */
@@ -183,27 +204,23 @@ serial_setbrg (void)
 void
 serial_putc(const char c)
 {
-       volatile cbd_t          *tbdf;
-       volatile char           *buf;
        volatile smc_uart_t     *up;
        volatile immap_t        *im = (immap_t *)CONFIG_SYS_IMMR;
+       volatile serialbuffer_t *rtx;
 
        if (c == '\n')
                serial_putc ('\r');
 
        up = (smc_uart_t *)&(im->im_dprambase[PROFF_SMC]);
 
-       tbdf = (cbd_t *)&im->im_dprambase[up->smc_tbase];
+       rtx = (serialbuffer_t *)&im->im_dprambase[up->smc_rbase];
 
-       /* Wait for last character to go.
-       */
-       buf = (char *)tbdf->cbd_bufaddr;
-       while (tbdf->cbd_sc & BD_SC_READY)
+       /* Wait for last character to go. */
+       while (rtx->txbd.cbd_sc & BD_SC_READY & BD_SC_READY)
                ;
-
-       *buf = c;
-       tbdf->cbd_datlen = 1;
-       tbdf->cbd_sc |= BD_SC_READY;
+       rtx->txbuf = c;
+       rtx->txbd.cbd_datlen = 1;
+       rtx->txbd.cbd_sc |= BD_SC_READY;
 }
 
 void
@@ -217,39 +234,45 @@ serial_puts (const char *s)
 int
 serial_getc(void)
 {
-       volatile cbd_t          *rbdf;
-       volatile unsigned char  *buf;
        volatile smc_uart_t     *up;
        volatile immap_t        *im = (immap_t *)CONFIG_SYS_IMMR;
-       unsigned char           c;
+       volatile serialbuffer_t *rtx;
+       unsigned char  c;
 
        up = (smc_uart_t *)&(im->im_dprambase[PROFF_SMC]);
 
-       rbdf = (cbd_t *)&im->im_dprambase[up->smc_rbase];
+       rtx = (serialbuffer_t *)&im->im_dprambase[up->smc_rbase];
 
        /* Wait for character to show up.
        */
-       buf = (unsigned char *)rbdf->cbd_bufaddr;
-       while (rbdf->cbd_sc & BD_SC_EMPTY)
+       while (rtx->rxbd.cbd_sc & BD_SC_EMPTY)
                ;
-       c = *buf;
-       rbdf->cbd_sc |= BD_SC_EMPTY;
 
+       /* the characters are read one by one,
+        * use the rxindex to know the next char to deliver
+        */
+       c = *(unsigned char *) (rtx->rxbd.cbd_bufaddr + rtx->rxindex);
+       rtx->rxindex++;
+
+       /* check if all char are readout, then make prepare for next receive */
+       if (rtx->rxindex >= rtx->rxbd.cbd_datlen) {
+               rtx->rxindex = 0;
+               rtx->rxbd.cbd_sc |= BD_SC_EMPTY;
+       }
        return(c);
 }
 
 int
 serial_tstc()
 {
-       volatile cbd_t          *rbdf;
        volatile smc_uart_t     *up;
        volatile immap_t        *im = (immap_t *)CONFIG_SYS_IMMR;
+       volatile serialbuffer_t *rtx;
 
        up = (smc_uart_t *)&(im->im_dprambase[PROFF_SMC]);
+       rtx = (serialbuffer_t *)&im->im_dprambase[up->smc_rbase];
 
-       rbdf = (cbd_t *)&im->im_dprambase[up->smc_rbase];
-
-       return(!(rbdf->cbd_sc & BD_SC_EMPTY));
+       return !(rtx->rxbd.cbd_sc & BD_SC_EMPTY);
 }
 
 #endif /* CONFIG_CONS_ON_SMC */