Hi Joshua, looks good to me; however, I think since you're adding initial support, I'd squash this together with [3/5]. On Fri, Oct 28, 2016 at 09:56:42AM -0700, Joshua Clayton wrote: > The status pin may not show ready in the time described in the > Altetera manual. check the value several times before giving up s/Altetera/Altera > For the hardware I am working on, the status pin takes 250 us, > 5 times as long as described by Altera. > > Signed-off-by: Joshua Clayton <stillcompiling@xxxxxxxxx> > --- > drivers/fpga/cyclone-ps-spi.c | 13 ++++++++----- > 1 file changed, 8 insertions(+), 5 deletions(-) > > diff --git a/drivers/fpga/cyclone-ps-spi.c b/drivers/fpga/cyclone-ps-spi.c > index 4b70d5c..c368223 100644 > --- a/drivers/fpga/cyclone-ps-spi.c > +++ b/drivers/fpga/cyclone-ps-spi.c > @@ -20,6 +20,7 @@ > > #define FPGA_RESET_TIME 50 /* time in usecs to trigger FPGA config */ > -#define FPGA_MIN_DELAY 250 /* min usecs to wait for config status */ > +#define FPGA_MIN_DELAY 50 /* min usecs to wait for config status */ > +#define FPGA_MAX_DELAY 1000 /* max usecs to wait for config status */ > > struct cyclonespi_conf { > struct gpio_desc *config; > @@ -42,6 +43,7 @@ static int cyclonespi_write_init(struct fpga_manager *mgr, u32 flags, > const char *buf, size_t count) > { > struct cyclonespi_conf *conf = (struct cyclonespi_conf *)mgr->priv; > + int i; > > if (flags & FPGA_MGR_PARTIAL_RECONFIG) { > dev_err(&mgr->dev, "Partial reconfiguration not supported.\n"); > @@ -56,13 +58,14 @@ static int cyclonespi_write_init(struct fpga_manager *mgr, u32 flags, > } > > gpiod_set_value(conf->config, 1); > - usleep_range(FPGA_MIN_DELAY, FPGA_MIN_DELAY + 20); > - if (gpiod_get_value(conf->status) == 0) { > - dev_err(&mgr->dev, "Status pin not ready.\n"); > - return -EIO; > + for (i = 0; i < (FPGA_MAX_DELAY / FPGA_MIN_DELAY); i++) { > + usleep_range(FPGA_MIN_DELAY, FPGA_MIN_DELAY + 20); > + if (gpiod_get_value(conf->status)) > + return 0; > } > > - return 0; > + dev_err(&mgr->dev, "Status pin not ready.\n"); > + return -EIO; > } > > static void rev_buf(void *buf, size_t len) > -- > 2.7.4 > Cheers, Moritz -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html