linux-mtd.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Dinh Nguyen <dinguyen@kernel.org>
To: linux-mtd@lists.infradead.org
Cc: marex@denx.de, Tien-Fong Chee <tien.fong.chee@intel.com>,
	vigneshr@ti.com, bbrezillon@kernel.org,
	tudor.ambarus@microchip.com, linux-kernel@vger.kernel.org,
	dinguyen@kernel.org, computersforpeace@gmail.com,
	dwmw2@infradead.org
Subject: [PATCHv2] mtd: spi-nor: cadence-quadspi: add reset control
Date: Tue,  9 Apr 2019 10:38:01 -0500	[thread overview]
Message-ID: <20190409153801.6941-1-dinguyen@kernel.org> (raw)

Get the reset control for the QSPI controller and bring it out of reset.

Suggested-by: Tien-Fong Chee <tien.fong.chee@intel.com>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
---
v2: use devm_reset_control_get_optional_exclusive
    print an error message
    return -EPROBE_DEFER
---
 drivers/mtd/spi-nor/cadence-quadspi.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
index 792628750eec..c548567adcf0 100644
--- a/drivers/mtd/spi-nor/cadence-quadspi.c
+++ b/drivers/mtd/spi-nor/cadence-quadspi.c
@@ -34,6 +34,7 @@
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/reset.h>
 #include <linux/sched.h>
 #include <linux/spi/spi.h>
 #include <linux/timer.h>
@@ -1336,6 +1337,7 @@ static int cqspi_probe(struct platform_device *pdev)
 	struct cqspi_st *cqspi;
 	struct resource *res;
 	struct resource *res_ahb;
+	struct reset_control *rstc;
 	const struct cqspi_driver_platdata *ddata;
 	int ret;
 	int irq;
@@ -1362,6 +1364,18 @@ static int cqspi_probe(struct platform_device *pdev)
 		return PTR_ERR(cqspi->clk);
 	}
 
+	/* Obtain QSPI reset control */
+	rstc = devm_reset_control_get_optional_exclusive(dev, NULL);
+	if (IS_ERR(rstc)) {
+		dev_err(dev, "Cannot get QSPI reset.\n");
+		if (PTR_ERR(rstc) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+	} else {
+		reset_control_assert(rstc);
+		udelay(1);
+		reset_control_deassert(rstc);
+	}
+
 	/* Obtain and remap controller address. */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	cqspi->iobase = devm_ioremap_resource(dev, res);
-- 
2.20.0


______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

             reply	other threads:[~2019-04-09 15:38 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-09 15:38 Dinh Nguyen [this message]
2019-04-17  8:48 ` [PATCHv2] mtd: spi-nor: cadence-quadspi: add reset control Tudor.Ambarus
2019-05-07 19:17   ` Dinh Nguyen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190409153801.6941-1-dinguyen@kernel.org \
    --to=dinguyen@kernel.org \
    --cc=bbrezillon@kernel.org \
    --cc=computersforpeace@gmail.com \
    --cc=dwmw2@infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mtd@lists.infradead.org \
    --cc=marex@denx.de \
    --cc=tien.fong.chee@intel.com \
    --cc=tudor.ambarus@microchip.com \
    --cc=vigneshr@ti.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).