[PATCH 1/2] spi: dw: add reset control

From: Dinh Nguyen <dinguyen@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: dinguyen@kernel.org, devicetree@vger.kernel.org,
	broonie@kernel.org, robh+dt@kernel.org,
	linux-spi@vger.kernel.org, Liang Jin J <liang.j.jin@ericsson.com>
Subject: [PATCH 1/2] spi: dw: add reset control
Date: Thu, 21 May 2020 12:03:58 -0500	[thread overview]
Message-ID: <20200521170359.20430-1-dinguyen@kernel.org> (raw)

Add mechanism to get the reset control and deassert it in order to bring
the IP out of reset.

Signed-off-by: Liang Jin J <liang.j.jin@ericsson.com>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
---
 drivers/spi/spi-dw-mmio.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c
index 384a3ab6dc2d..5c813e15ed89 100644
--- a/drivers/spi/spi-dw-mmio.c
+++ b/drivers/spi/spi-dw-mmio.c
@@ -20,6 +20,7 @@
 #include <linux/acpi.h>
 #include <linux/property.h>
 #include <linux/regmap.h>
+#include <linux/reset.h>
 
 #include "spi-dw.h"
 
@@ -30,6 +31,7 @@ struct dw_spi_mmio {
 	struct clk     *clk;
 	struct clk     *pclk;
 	void           *priv;
+	struct reset_control	*rstc;
 };
 
 #define MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL	0x24
@@ -145,6 +147,10 @@ static int dw_spi_mmio_probe(struct platform_device *pdev)
 	if (!dwsmmio)
 		return -ENOMEM;
 
+	dwsmmio->rstc = devm_reset_control_get_exclusive(&pdev->dev, "spi");
+	if (!IS_ERR(dwsmmio->rstc))
+		reset_control_deassert(dwsmmio->rstc);
+
 	dws = &dwsmmio->dws;
 
 	/* Get basic io resource and map it */
@@ -220,6 +226,9 @@ static int dw_spi_mmio_remove(struct platform_device *pdev)
 	clk_disable_unprepare(dwsmmio->pclk);
 	clk_disable_unprepare(dwsmmio->clk);
 
+	if (dwsmmio->rstc)
+		reset_control_assert(dwsmmio->rstc);
+
 	return 0;
 }
 
-- 
2.17.1

