staging: comedi: daqboard2000: check result of FPGA programming

According to an old, GPL'ed Linux driver at
<ftp://ftp.mccdaq.com/downloads/iotech_software/DaqBoard_1000_2000_Series/Linux_driver_kernelv2.4.x/>,
after programming the FPGA, the General Purpose Input (USERI) of the PLX
PCI-9080 should go high shortly after a valid FPGA bitstream has been
loaded.  Add a new function `daqboard2000_wait_fpga_programmed()` to
wait for that, performing up to 200 checks over a 20 ms period (this is
loosely based on `pollFPGADone()` in the above-mentioned old driver).
Return 0 if the FPGA appears to have loaded successfully, or
`-ETIMEDOUT` if it runs out of checks.  Call it from the firmware
loading callback `daqboard2000_load_firmware()` after writing the
firmware to the FPGA to check it is programmed successfully.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/daqboard2000.c b/drivers/staging/comedi/drivers/daqboard2000.c
index d6f30261db9b37b5c1d27dcaa380fb1a2dc2f018..4e3e81186bc377b124b71b6ded4f342e00580819 100644 (file)
--- a/drivers/staging/comedi/drivers/daqboard2000.c
+++ b/drivers/staging/comedi/drivers/daqboard2000.c
@@ -501,6 +501,23 @@ static int daqboard2000_write_cpld(struct comedi_device *dev, u16 data)
        return result;
 }
 
+static int daqboard2000_wait_fpga_programmed(struct comedi_device *dev)
+{
+       struct daqboard2000_private *devpriv = dev->private;
+       int i;
+
+       /* Time out after 200 tries -> 20ms */
+       for (i = 0; i < 200; i++) {
+               u32 cntrl = readl(devpriv->plx + PLX_REG_CNTRL);
+               /* General Purpose Input (USERI) set on FPGA "DONE". */
+               if (cntrl & PLX_CNTRL_USERI)
+                       return 0;
+
+               usleep_range(100, 1000);
+       }
+       return -ETIMEDOUT;
+}
+
 static int daqboard2000_load_firmware(struct comedi_device *dev,
                                      const u8 *cpld_array, size_t len,
                                      unsigned long context)
@@ -551,6 +568,8 @@ static int daqboard2000_load_firmware(struct comedi_device *dev,
                        if (result)
                                break;
                }
+               if (result == 0)
+                       result = daqboard2000_wait_fpga_programmed(dev);
                if (result == 0) {
                        daqboard2000_reset_local_bus(dev);
                        daqboard2000_reload_plx(dev);