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

Message ID 20200521170359.20430-1-dinguyen@kernel.org
State New
Headers show
Series
  • [1/2] spi: dw: add reset control
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Commit Message

Dinh Nguyen May 21, 2020, 5:03 p.m.
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(+)

Patch

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;
 }