[PATCH 19/19] staging: comedi: ni_labpc_common: use comedi_timeout() when writing to eeprom

[H Hartley Sweeten]

Use the comedi_timeout() helper to wait for the eeprom to be ready to accept
writes and remove the timeout loop in labpc_eeprom_write().

Signed-off-by: H Hartley Sweeten <hswee...@visionengravers.com>
Cc: Ian Abbott <abbo...@mev.co.uk>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/staging/comedi/drivers/ni_labpc_common.c | 37 ++++++++++++------------
 1 file changed, 18 insertions(+), 19 deletions(-)

diff --git a/drivers/staging/comedi/drivers/ni_labpc_common.c 
b/drivers/staging/comedi/drivers/ni_labpc_common.c
index 9d26aced..d89d585 100644
--- a/drivers/staging/comedi/drivers/ni_labpc_common.c
+++ b/drivers/staging/comedi/drivers/ni_labpc_common.c
@@ -1078,27 +1078,13 @@ static unsigned int labpc_eeprom_read_status(struct 
comedi_device *dev)
        return value;
 }
 
-static int labpc_eeprom_write(struct comedi_device *dev,
-                             unsigned int address, unsigned int value)
+static void labpc_eeprom_write(struct comedi_device *dev,
+                              unsigned int address, unsigned int value)
 {
        struct labpc_private *devpriv = dev->private;
        const int write_enable_instruction = 0x6;
        const int write_instruction = 0x2;
        const int write_length = 8;     /*  8 bit write lengths to eeprom */
-       const int write_in_progress_bit = 0x1;
-       const int timeout = 10000;
-       int i;
-
-       /*  make sure there isn't already a write in progress */
-       for (i = 0; i < timeout; i++) {
-               if ((labpc_eeprom_read_status(dev) & write_in_progress_bit) ==
-                   0)
-                       break;
-       }
-       if (i == timeout) {
-               dev_err(dev->class_dev, "eeprom write timed out\n");
-               return -ETIME;
-       }
 
        /*  enable read/write to eeprom */
        devpriv->cmd5 &= ~CMD5_EEPROMCS;
@@ -1131,8 +1117,6 @@ static int labpc_eeprom_write(struct comedi_device *dev,
        devpriv->cmd5 &= ~(CMD5_EEPROMCS | CMD5_WRTPRT);
        udelay(1);
        devpriv->write_byte(dev, devpriv->cmd5, CMD5_REG);
-
-       return 0;
 }
 
 /* writes to 8 bit calibration dacs */
@@ -1183,6 +1167,20 @@ static int labpc_calib_insn_write(struct comedi_device 
*dev,
        return insn->n;
 }
 
+static int labpc_eeprom_ready(struct comedi_device *dev,
+                             struct comedi_subdevice *s,
+                             struct comedi_insn *insn,
+                             unsigned long context)
+{
+       unsigned int status;
+
+       /* make sure there isn't already a write in progress */
+       status = labpc_eeprom_read_status(dev);
+       if ((status & 0x1) == 0)
+               return 0;
+       return -EBUSY;
+}
+
 static int labpc_eeprom_insn_write(struct comedi_device *dev,
                                   struct comedi_subdevice *s,
                                   struct comedi_insn *insn,
@@ -1202,10 +1200,11 @@ static int labpc_eeprom_insn_write(struct comedi_device 
*dev,
        if (insn->n > 0) {
                unsigned int val = data[insn->n - 1];
 
-               ret = labpc_eeprom_write(dev, chan, val);
+               ret = comedi_timeout(dev, s, insn, labpc_eeprom_ready, 0);
                if (ret)
                        return ret;
 
+               labpc_eeprom_write(dev, chan, val);
                s->readback[chan] = val;
        }
 
-- 
2.0.3

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