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

From: Dinh Nguyen
Date: Thu May 21 2020 - 13:04:11 EST


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@xxxxxxxxxxxx>
Signed-off-by: Dinh Nguyen <dinguyen@xxxxxxxxxx>
---
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