2007-10-11 Daniel Hellstrom <daniel@gaisler.com>

	* Makefile.am, shared/can/occan.c, shared/include/ambapp.h: Add initial
	i2c and update OC-CAN support.
	* shared/i2c/i2cmst.c, shared/include/i2cmst.h: New files.

1 files changed, 358 insertions, 0 deletions

diff --git a/c/src/lib/libbsp/sparc/shared/i2c/i2cmst.c b/c/src/lib/libbsp/sparc/shared/i2c/i2cmst.c
new file mode 100644
index 0000000000..2a59d32879
--- /dev/null
+++ b/c/src/lib/libbsp/sparc/shared/i2c/i2cmst.c
@@ -0,0 +1,358 @@
+/*
+ * Driver for GRLIB port of OpenCores I2C-master
+ *
+ * COPYRIGHT (c) 2007 Gaisler Research
+ * based on the RTEMS MPC83xx I2C driver (c) 2007 Embedded Brains GmbH.
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ *
+ * This file contains the driver and initialization code
+ *
+ * 2007-09-27: First version of driver (jan@gaisler.com)
+ */
+
+
+#include <bsp.h>
+#include <i2cmst.h>
+#include <ambapp.h>
+#include <rtems/libi2c.h>
+
+/* Enable debug printks? */
+/* #define DEBUG */
+
+/* Default to 40 MHz system clock? */
+/*
+  #ifndef SYS_FREQ_kHZ
+  #define SYS_FREQ_kHZ 40000
+  #endif
+*/
+
+
+/* Calculates the scaler value for 100 kHz operation */
+static int gr_i2cmst_calc_scaler(int sysfreq)
+{
+  return sysfreq/500 - 1;
+}
+
+/* Wait for the current transfer to end */
+static int gr_i2cmst_wait(gr_i2cmst_prv_t *prv_ptr, uint8_t expected_sts)
+{
+  uint32_t tout = 0;
+  int current_sts;
+#if defined(DEBUG)
+  printk("(gr_i2cmst_wait called...");
+#endif
+
+  do {
+    if (tout++ > 1000000) {
+      return RTEMS_TIMEOUT;
+    }
+  } while (prv_ptr->reg_ptr->cmdsts & GRI2C_STS_TIP);
+
+  current_sts = prv_ptr->reg_ptr->cmdsts & ~GRI2C_STS_IF & ~GRI2C_STS_BUSY;
+
+  if (current_sts != expected_sts) {
+#if defined(DEBUG)
+    if (prv_ptr->reg_ptr->cmdsts & GRI2C_STS_RXACK) {
+      printk("Transfer NAKed..");
+    }
+    if (prv_ptr->reg_ptr->cmdsts & GRI2C_STS_AL) {
+      printk("arbitration lost..");
+    }
+    if (prv_ptr->reg_ptr->cmdsts & GRI2C_STS_TIP) {
+      printk("transfer still in progress, huh?..");
+    }
+    printk("exited with IO error..)");
+#endif
+    return RTEMS_IO_ERROR;
+  }
+
+#if defined(DEBUG)
+  printk("exited...)");
+#endif
+  return RTEMS_SUCCESSFUL;
+}
+
+/* Initialize hardware core */
+static rtems_status_code gr_i2cmst_init(rtems_libi2c_bus_t *bushdl)
+{
+  gr_i2cmst_prv_t *prv_ptr = &(((gr_i2cmst_desc_t *)(bushdl))->prv);
+#if defined(DEBUG)
+  printk("gr_i2cmst_init called...");
+#endif
+
+  /* Disable core before changing prescale register */
+  prv_ptr->reg_ptr->ctrl = 0;
+
+  /* Calculate and set prescale value */
+  prv_ptr->reg_ptr->prescl = gr_i2cmst_calc_scaler(prv_ptr->sysfreq);
+
+  /* Enable core, interrupts are not enabled */
+  prv_ptr->reg_ptr->ctrl = GRI2C_CTRL_EN;
+
+  /* Clear possible START condition */
+  prv_ptr->sendstart = 0;
+
+#if defined(DEBUG)
+  printk("exited\n");
+#endif
+  return RTEMS_SUCCESSFUL;
+}
+
+static rtems_status_code gr_i2cmst_send_start(rtems_libi2c_bus_t *bushdl)
+{
+  gr_i2cmst_prv_t *prv_ptr = &(((gr_i2cmst_desc_t *)(bushdl))->prv);
+#if defined(DEBUG)
+  printk("gr_i2cmst_send_start called...");
+#endif 
+  
+  /* The OC I2C core does not work with stand alone START events,
+     instead the event is buffered */
+  prv_ptr->sendstart = GRI2C_CMD_STA;
+
+#if defined(DEBUG)
+  printk("exited\n");
+#endif
+  return RTEMS_SUCCESSFUL;
+}
+
+static rtems_status_code gr_i2cmst_send_stop(rtems_libi2c_bus_t *bushdl)
+{
+  gr_i2cmst_prv_t *prv_ptr = &(((gr_i2cmst_desc_t *)(bushdl))->prv);
+#if defined(DEBUG)
+  printk("gr_i2cmst_send_stop called...");
+#endif 
+
+  prv_ptr->reg_ptr->cmdsts = GRI2C_CMD_STO;
+
+#if defined(DEBUG)
+  printk("exited\n");
+#endif
+  return RTEMS_SUCCESSFUL;
+}
+
+static rtems_status_code gr_i2cmst_send_addr(rtems_libi2c_bus_t *bushdl,
+					     uint32_t addr, int rw)
+{
+  gr_i2cmst_prv_t *prv_ptr = &(((gr_i2cmst_desc_t *)(bushdl))->prv);
+  uint8_t addr_byte;
+  rtems_status_code rc;
+#if defined(DEBUG)
+  printk("gr_i2cmst_send_addr called, addr = 0x%x, rw = %d...", 
+	 addr, rw);
+#endif
+
+  /*  Check if long address is needed */
+  if (addr > 0x7f) {
+    addr_byte = ((addr >> 7) & 0x06) | (rw ? 1 : 0);
+    
+    prv_ptr->reg_ptr->tdrd = addr_byte;
+    prv_ptr->reg_ptr->cmdsts = GRI2C_CMD_WR | prv_ptr->sendstart;
+    prv_ptr->sendstart = 0;
+
+    /* Wait for transfer to complete */
+    rc = gr_i2cmst_wait(prv_ptr, GRI2C_STATUS_IDLE);
+    if (rc != RTEMS_SUCCESSFUL) {
+#if defined(DEBUG)
+  printk("exited with error\n");
+#endif
+      return -rc;
+    }
+  }
+
+  /* For 10-bit adresses the last byte should only be written for a
+     write operation  */
+  rc = RTEMS_SUCCESSFUL;
+  if (addr <= 0x7f || rw == 0) {
+    addr_byte = (addr << 1) | (rw ? 1 : 0);
+
+    prv_ptr->reg_ptr->tdrd = addr_byte;
+    prv_ptr->reg_ptr->cmdsts = GRI2C_CMD_WR | prv_ptr->sendstart;
+    prv_ptr->sendstart = 0;
+
+    /* Wait for transfer to complete */
+    rc = gr_i2cmst_wait(prv_ptr, GRI2C_STATUS_IDLE);
+    if (rc != RTEMS_SUCCESSFUL) {
+#if defined(DEBUG)
+  printk("exited with error\n");
+#endif
+      return -rc;
+    }
+ }
+
+#if defined(DEBUG)
+  printk("exited\n");
+#endif
+  return rc;
+}
+
+
+static int gr_i2cmst_read_bytes(rtems_libi2c_bus_t *bushdl, 
+				unsigned char *bytes, int nbytes)
+{
+  gr_i2cmst_prv_t *prv_ptr = &(((gr_i2cmst_desc_t *)(bushdl))->prv);
+  unsigned char *buf = bytes;
+  rtems_status_code rc;
+  unsigned char expected_sts = GRI2C_STATUS_IDLE;
+#if defined(DEBUG)
+  printk("gr_i2cmst_read_bytes called, nbytes = %d...", nbytes);
+#endif
+
+  while (nbytes-- > 0) {
+    if (nbytes == 0) {
+      /* Respond with NAK to end sequential read */
+      prv_ptr->reg_ptr->cmdsts = (GRI2C_CMD_RD | GRI2C_CMD_ACK |
+				  prv_ptr->sendstart);
+      expected_sts = GRI2C_STS_RXACK;
+    } else {
+      prv_ptr->reg_ptr->cmdsts = GRI2C_CMD_RD | prv_ptr->sendstart;      
+    }
+    prv_ptr->sendstart = 0;
+    /* Wait until end of transfer */
+    rc = gr_i2cmst_wait(prv_ptr, expected_sts);
+    if (rc != RTEMS_SUCCESSFUL) {
+      return -rc;
+#if defined(DEBUG)
+  printk("exited with error\n");
+#endif
+    }
+    *buf++ = prv_ptr->reg_ptr->tdrd;
+  }
+
+#if defined(DEBUG)
+  printk("exited\n");
+#endif
+  return buf - bytes;
+}
+
+static int gr_i2cmst_write_bytes(rtems_libi2c_bus_t *bushdl, 
+				unsigned char *bytes, int nbytes)
+{
+  gr_i2cmst_prv_t *prv_ptr = &(((gr_i2cmst_desc_t *)(bushdl))->prv);
+  unsigned char *buf = bytes;
+  rtems_status_code rc;
+#if defined(DEBUG)
+  printk("gr_i2cmst_write_bytes called, nbytes = %d...", nbytes);
+#endif   
+
+  while (nbytes-- > 0) {
+#if defined(DEBUG)
+  printk("writing byte 0x%02X...", *buf);
+#endif   
+    prv_ptr->reg_ptr->tdrd = *buf++;
+    prv_ptr->reg_ptr->cmdsts = GRI2C_CMD_WR | prv_ptr->sendstart;
+    prv_ptr->sendstart = 0;
+
+    /* Wait for transfer to complete  */
+    rc = gr_i2cmst_wait(prv_ptr, GRI2C_STATUS_IDLE);
+    
+    if (rc != RTEMS_SUCCESSFUL) {
+#if defined(DEBUG)
+  printk("exited with error\n");
+#endif
+      return -rc;
+    }
+  }
+
+#if defined(DEBUG)
+  printk("exited\n");
+#endif
+  return buf - bytes;
+}
+
+static rtems_libi2c_bus_ops_t gr_i2cmst_ops = {
+  init:        gr_i2cmst_init,
+  send_start:  gr_i2cmst_send_start,
+  send_stop:   gr_i2cmst_send_stop,
+  send_addr:   gr_i2cmst_send_addr,
+  read_bytes:  gr_i2cmst_read_bytes,
+  write_bytes: gr_i2cmst_write_bytes,
+};
+
+
+static gr_i2cmst_desc_t gr_i2cmst_desc = {
+  { /* rtems_libi2c_bus_t */
+    ops     : &gr_i2cmst_ops,
+    size    : sizeof(gr_i2cmst_ops), 
+  },
+  { /* gr_i2cmst_prv_t, private data */
+    reg_ptr : NULL,
+    sysfreq : 40000,
+  }
+  
+};
+
+/* Scans for I2CMST core and initalizes i2c library */
+rtems_status_code leon_register_i2c(amba_confarea_type *abus)
+{
+#if defined(DEBUG)
+  printk("leon_register_i2c called...");
+#endif
+
+  int rc;
+  int device_found = 0;
+  amba_apb_device apbi2cmst;
+  
+  /* Scan AMBA bus for I2CMST core */
+  device_found = amba_find_apbslv(abus, VENDOR_GAISLER, GAISLER_I2CMST,
+				  &apbi2cmst);
+
+  if (device_found == 1) {
+    
+    /* Initialize i2c library */
+    rc = rtems_libi2c_initialize();
+    if (rc < 0) {
+#if defined(DEBUG)
+      printk("rtems_libi2x_initialize failed, exiting...\n");
+#endif
+      return rc;
+    }
+
+    gr_i2cmst_desc.prv.reg_ptr = (gr_i2cmst_regs_t *)apbi2cmst.start;
+    
+    /* Detect system frequency, same as in apbuart_initialize */
+#ifndef SYS_FREQ_kHZ
+#if defined(LEON3)
+	/* LEON3: find timer address via AMBA Plug&Play info */	
+	{
+	  amba_apb_device gptimer;
+	  LEON3_Timer_Regs_Map *tregs;
+	  
+	  if (amba_find_apbslv(abus,VENDOR_GAISLER,
+			       GAISLER_GPTIMER,&gptimer) == 1 ) {
+	    tregs = (LEON3_Timer_Regs_Map *)gptimer.start;
+	    gr_i2cmst_desc.prv.sysfreq = (tregs->scaler_reload+1)*1000;
+	  } else {
+	    gr_i2cmst_desc.prv.sysfreq = 40000; /* Default to 40MHz */  
+	  }
+	}
+#elif defined(LEON2)
+	/* LEON2: use hardcoded address to get to timer */
+	{
+	  LEON_Register_Map *regs = (LEON_Register_Map *)0x80000000;
+	  gr_i2cmst_desc.prv.sysfreq = (regs->Scaler_Reload+1)*1000;
+	}
+#else
+#error CPU not supported for I2CMST driver */
+#endif
+#else
+	/* Use hardcoded frequency */
+	gr_i2cmst_desc.prv.sysfreq = SYS_FREQ_kHZ;
+#endif
+
+    rc = rtems_libi2c_register_bus("/dev/i2c1", &gr_i2cmst_desc.bus_desc);
+    if (rc < 0) {
+#if defined(DEBUG)
+      printk("rtems_libi2c_register_bus failed, exiting..\n");
+#endif
+      return -rc;
+    }
+  }
+  
+#if defined(DEBUG)
+  printk("exited\n");
+#endif
+  return 0;
+}