From: moritz.fischer@ettus•com (Moritz Fischer)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 5/5] fpga manager: cyclone-ps-spi: make delay variable
Date: Fri, 28 Oct 2016 10:41:42 -0700 [thread overview]
Message-ID: <20161028174142.GA18325@live.com> (raw)
In-Reply-To: <2239ffc8aba7d053825d2bea122a3c16cdd9f6e1.1477669745.git.stillcompiling@gmail.com>
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@gmail•com>
> ---
> 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
next prev parent reply other threads:[~2016-10-28 17:41 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-28 16:56 [PATCH v2 0/4] Altera Cyclone Passive Serial SPI FPGA Manager Joshua Clayton
2016-10-28 16:56 ` [PATCH v2 1/5] lib: add bitrev8x4() Joshua Clayton
2016-10-28 18:50 ` kbuild test robot
2016-10-28 16:56 ` [PATCH v2 2/5] doc: dt: add cyclone-spi binding document Joshua Clayton
2016-10-31 6:16 ` Rob Herring
2016-10-28 16:56 ` [PATCH v2 3/5] fpga manager: Add cyclone-ps-spi driver for Altera FPGAs Joshua Clayton
2016-10-28 18:55 ` kbuild test robot
2016-10-28 19:26 ` kbuild test robot
2016-10-28 20:41 ` kbuild test robot
2016-10-28 21:05 ` Joshua Clayton
2016-10-28 16:56 ` [PATCH v2 4/5] ARM: dts: imx6q-evi: support cyclonespi Joshua Clayton
2016-10-28 16:56 ` [PATCH v2 5/5] fpga manager: cyclone-ps-spi: make delay variable Joshua Clayton
2016-10-28 17:41 ` Moritz Fischer [this message]
2016-10-28 19:49 ` Joshua Clayton
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