[PATCH] zynq-fpga: Only route PR via PCAP when required

From: Mike Looijmans <mike.looijmans@topic.nl>
To: linux-fpga@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, michal.simek@xilinx.com,
	mdf@kernel.org, atull@kernel.org,
	Mike Looijmans <mike.looijmans@topic.nl>
Subject: [PATCH] zynq-fpga: Only route PR via PCAP when required
Date: Tue, 23 Oct 2018 08:31:19 +0200	[thread overview]
Message-ID: <1540276279-2903-1-git-send-email-mike.looijmans@topic.nl> (raw)

The Xilinx Zynq FPGA driver takes ownership of the PR interface, making
it impossible to use the ICAP interface for partial reconfiguration.

This patch changes the driver to only activate PR over PCAP while the
device is actively being accessed by the driver for programming.

This allows both PCAP and ICAP interfaces to be used for PR.

Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
---
 drivers/fpga/zynq-fpga.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
index 3110e00..f6c205a 100644
--- a/drivers/fpga/zynq-fpga.c
+++ b/drivers/fpga/zynq-fpga.c
@@ -497,6 +497,10 @@ static int zynq_fpga_ops_write_complete(struct fpga_manager *mgr,
 	int err;
 	u32 intr_status;
 
+	/* Release 'PR' control back to the ICAP */
+	zynq_fpga_write(priv, CTRL_OFFSET,
+		zynq_fpga_read(priv, CTRL_OFFSET) & ~CTRL_PCAP_PR_MASK);
+
 	err = clk_enable(priv->clk);
 	if (err)
 		return err;
-- 
1.9.1

