From d8644e418b2613b3eaf1e10fe6fd0d84018c2f8a Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 10 Feb 2014 11:49:38 -0700 Subject: [PATCH] staging: comedi: dt282x: use comedi_timeout() The wait_for() macro in this driver is a bit nasty. It effects control flow which according to the CodingStyle is a _very_ bad idea. The mux_busy() and ad_done() macros are also bad since they rely on a local variable having a specific name. Remove these macros and use comedi_timeout() to wait for the analog input mux busy completion and end-of-conversion. Both of these are detected by reading the same register and testing different bits. Pass the bits to test as the 'context' to the callback function. The dt282x_ai_cmd() function also checks for the mux busy completion. The 'insn' is not available here but passing NULL is safe because nothing uses it. Signed-off-by: H Hartley Sweeten Cc: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/dt282x.c | 68 +++++++++++++++---------- 1 file changed, 42 insertions(+), 26 deletions(-) diff --git a/drivers/staging/comedi/drivers/dt282x.c b/drivers/staging/comedi/drivers/dt282x.c index 895f73a19023..f768210184c1 100644 --- a/drivers/staging/comedi/drivers/dt282x.c +++ b/drivers/staging/comedi/drivers/dt282x.c @@ -63,7 +63,6 @@ Notes: #include "comedi_fc.h" -#define DT2821_TIMEOUT 100 /* 500 us */ #define DT2821_SIZE 0x10 /* @@ -248,27 +247,6 @@ struct dt282x_private { * Some useless abstractions */ #define chan_to_DAC(a) ((a)&1) -#define mux_busy() (inw(dev->iobase+DT2821_ADCSR)&DT2821_MUXBUSY) -#define ad_done() (inw(dev->iobase+DT2821_ADCSR)&DT2821_ADDONE) - -/* - * danger! macro abuse... a is the expression to wait on, and b is - * the statement(s) to execute if it doesn't happen. - */ -#define wait_for(a, b) \ - do { \ - int _i; \ - for (_i = 0; _i < DT2821_TIMEOUT; _i++) { \ - if (a) { \ - _i = 0; \ - break; \ - } \ - udelay(5); \ - } \ - if (_i) { \ - b \ - } \ - } while (0) static int prep_ai_dma(struct comedi_device *dev, int chan, int size); static int prep_ao_dma(struct comedi_device *dev, int chan, int size); @@ -530,6 +508,29 @@ static void dt282x_load_changain(struct comedi_device *dev, int n, outw(n - 1, dev->iobase + DT2821_CHANCSR); } +static int dt282x_ai_timeout(struct comedi_device *dev, + struct comedi_subdevice *s, + struct comedi_insn *insn, + unsigned long context) +{ + unsigned int status; + + status = inw(dev->iobase + DT2821_ADCSR); + switch (context) { + case DT2821_MUXBUSY: + if ((status & DT2821_MUXBUSY) == 0) + return 0; + break; + case DT2821_ADDONE: + if (status & DT2821_ADDONE) + return 0; + break; + default: + return -EINVAL; + } + return -EBUSY; +} + /* * Performs a single A/D conversion. * - Put channel/gain into channel-gain list @@ -542,6 +543,7 @@ static int dt282x_ai_insn_read(struct comedi_device *dev, { const struct dt282x_board *board = comedi_board(dev); struct dt282x_private *devpriv = dev->private; + int ret; int i; /* XXX should we really be enabling the ad clock here? */ @@ -551,13 +553,22 @@ static int dt282x_ai_insn_read(struct comedi_device *dev, dt282x_load_changain(dev, 1, &insn->chanspec); outw(devpriv->supcsr | DT2821_PRLD, dev->iobase + DT2821_SUPCSR); - wait_for(!mux_busy(), comedi_error(dev, "timeout\n"); return -ETIME;); + ret = comedi_timeout(dev, s, insn, dt282x_ai_timeout, DT2821_MUXBUSY); + if (ret) { + comedi_error(dev, "timeout\n"); + return ret; + } for (i = 0; i < insn->n; i++) { outw(devpriv->supcsr | DT2821_STRIG, dev->iobase + DT2821_SUPCSR); - wait_for(ad_done(), comedi_error(dev, "timeout\n"); - return -ETIME;); + + ret = comedi_timeout(dev, s, insn, dt282x_ai_timeout, + DT2821_ADDONE); + if (ret) { + comedi_error(dev, "timeout\n"); + return ret; + } data[i] = inw(dev->iobase + @@ -646,6 +657,7 @@ static int dt282x_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s) struct dt282x_private *devpriv = dev->private; struct comedi_cmd *cmd = &s->async->cmd; int timer; + int ret; if (devpriv->usedma == 0) { comedi_error(dev, @@ -691,7 +703,11 @@ static int dt282x_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s) outw(devpriv->adcsr, dev->iobase + DT2821_ADCSR); outw(devpriv->supcsr | DT2821_PRLD, dev->iobase + DT2821_SUPCSR); - wait_for(!mux_busy(), comedi_error(dev, "timeout\n"); return -ETIME;); + ret = comedi_timeout(dev, s, NULL, dt282x_ai_timeout, DT2821_MUXBUSY); + if (ret) { + comedi_error(dev, "timeout\n"); + return ret; + } if (cmd->scan_begin_src == TRIG_FOLLOW) { outw(devpriv->supcsr | DT2821_STRIG, -- 2.39.5