staging: comedi: cb_pcidas: fix cb_pcidas_eeprom_insn_read()

The comedi core expects (*insn_read) operations to return insn->n
data values. Refactor this function to work like the core expects.

For aesthetics, nvram_read() and use the comedi_timeout() helper
to handle the busy wait for the eeprom to be "ready".

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

diff --git a/drivers/staging/comedi/drivers/cb_pcidas.c b/drivers/staging/comedi/drivers/cb_pcidas.c
index 3238cabca7acae15810af21da6199eb3972b63c1..c0ae92dc9fa29f6f841426ae895b6a1561bad38d 100644 (file)
--- a/drivers/staging/comedi/drivers/cb_pcidas.c
+++ b/drivers/staging/comedi/drivers/cb_pcidas.c
@@ -466,44 +466,18 @@ static int cb_pcidas_ao_fifo_winsn(struct comedi_device *dev,
        return insn->n;
 }
 
-static int wait_for_nvram_ready(unsigned long s5933_base_addr)
-{
-       static const int timeout = 1000;
-       unsigned int i;
-
-       for (i = 0; i < timeout; i++) {
-               if ((inb(s5933_base_addr +
-                        AMCC_OP_REG_MCSR_NVCMD) & MCSR_NV_BUSY)
-                   == 0)
-                       return 0;
-               udelay(1);
-       }
-       return -1;
-}
-
-static int nvram_read(struct comedi_device *dev, unsigned int address,
-                     u8 *data)
+static int cb_pcidas_eeprom_ready(struct comedi_device *dev,
+                                 struct comedi_subdevice *s,
+                                 struct comedi_insn *insn,
+                                 unsigned long context)
 {
        struct cb_pcidas_private *devpriv = dev->private;
-       unsigned long iobase = devpriv->s5933_config;
-
-       if (wait_for_nvram_ready(iobase) < 0)
-               return -ETIMEDOUT;
-
-       outb(MCSR_NV_ENABLE | MCSR_NV_LOAD_LOW_ADDR,
-            iobase + AMCC_OP_REG_MCSR_NVCMD);
-       outb(address & 0xff, iobase + AMCC_OP_REG_MCSR_NVDATA);
-       outb(MCSR_NV_ENABLE | MCSR_NV_LOAD_HIGH_ADDR,
-            iobase + AMCC_OP_REG_MCSR_NVCMD);
-       outb((address >> 8) & 0xff, iobase + AMCC_OP_REG_MCSR_NVDATA);
-       outb(MCSR_NV_ENABLE | MCSR_NV_READ, iobase + AMCC_OP_REG_MCSR_NVCMD);
-
-       if (wait_for_nvram_ready(iobase) < 0)
-               return -ETIMEDOUT;
-
-       *data = inb(iobase + AMCC_OP_REG_MCSR_NVDATA);
+       unsigned int status;
 
-       return 0;
+       status = inb(devpriv->s5933_config + AMCC_OP_REG_MCSR_NVCMD);
+       if ((status & MCSR_NV_BUSY) == 0)
+               return 0;
+       return -EBUSY;
 }
 
 static int cb_pcidas_eeprom_insn_read(struct comedi_device *dev,
@@ -511,16 +485,38 @@ static int cb_pcidas_eeprom_insn_read(struct comedi_device *dev,
                                      struct comedi_insn *insn,
                                      unsigned int *data)
 {
-       u8 nvram_data;
-       int retval;
+       struct cb_pcidas_private *devpriv = dev->private;
+       unsigned int chan = CR_CHAN(insn->chanspec);
+       int ret;
+       int i;
 
-       retval = nvram_read(dev, CR_CHAN(insn->chanspec), &nvram_data);
-       if (retval < 0)
-               return retval;
+       for (i = 0; i < insn->n; i++) {
+               /* make sure eeprom is ready */
+               ret = comedi_timeout(dev, s, insn, cb_pcidas_eeprom_ready, 0);
+               if (ret)
+                       return ret;
+
+               /* set address (chan) and read operation */
+               outb(MCSR_NV_ENABLE | MCSR_NV_LOAD_LOW_ADDR,
+                    devpriv->s5933_config + AMCC_OP_REG_MCSR_NVCMD);
+               outb(chan & 0xff,
+                    devpriv->s5933_config + AMCC_OP_REG_MCSR_NVDATA);
+               outb(MCSR_NV_ENABLE | MCSR_NV_LOAD_HIGH_ADDR,
+                    devpriv->s5933_config + AMCC_OP_REG_MCSR_NVCMD);
+               outb((chan >> 8) & 0xff,
+                    devpriv->s5933_config + AMCC_OP_REG_MCSR_NVDATA);
+               outb(MCSR_NV_ENABLE | MCSR_NV_READ,
+                    devpriv->s5933_config + AMCC_OP_REG_MCSR_NVCMD);
+
+               /* wait for data to be returned */
+               ret = comedi_timeout(dev, s, insn, cb_pcidas_eeprom_ready, 0);
+               if (ret)
+                       return ret;
 
-       data[0] = nvram_data;
+               data[i] = inb(devpriv->s5933_config + AMCC_OP_REG_MCSR_NVDATA);
+       }
 
-       return 1;
+       return insn->n;
 }
 
 static void cb_pcidas_calib_write(struct comedi_device *dev,