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authorDinh Nguyen <dinguyen@kernel.org>2020-05-29 10:58:05 -0500
committerMark Brown <broonie@kernel.org>2020-05-29 17:49:55 +0100
commit7830c0ef26cb73b653c2db2f3ca7be08f44fa046 (patch)
tree96bc89027ad2fe21653a52a89f34dfae6be9a36b /drivers/spi
parentecfbd3cf3b8bb73ac6a80ddf430b5912fd4402a6 (diff)
downloadlinux-7830c0ef26cb73b653c2db2f3ca7be08f44fa046.tar.bz2
spi: dw: add reset control
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> Link: https://lore.kernel.org/r/20200529155806.16758-1-dinguyen@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-dw-mmio.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c
index 0894b4c09496..a1b87d4606ba 100644
--- a/drivers/spi/spi-dw-mmio.c
+++ b/drivers/spi/spi-dw-mmio.c
@@ -19,6 +19,7 @@
#include <linux/acpi.h>
#include <linux/property.h>
#include <linux/regmap.h>
+#include <linux/reset.h>
#include "spi-dw.h"
@@ -29,6 +30,7 @@ struct dw_spi_mmio {
struct clk *clk;
struct clk *pclk;
void *priv;
+ struct reset_control *rstc;
};
#define MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL 0x24
@@ -224,6 +226,14 @@ static int dw_spi_mmio_probe(struct platform_device *pdev)
if (ret)
goto out_clk;
+ /* find an optional reset controller */
+ dwsmmio->rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, "spi");
+ if (IS_ERR(dwsmmio->rstc)) {
+ ret = PTR_ERR(dwsmmio->rstc);
+ goto out_clk;
+ }
+ reset_control_deassert(dwsmmio->rstc);
+
dws->bus_num = pdev->id;
dws->max_freq = clk_get_rate(dwsmmio->clk);
@@ -257,6 +267,8 @@ out:
clk_disable_unprepare(dwsmmio->pclk);
out_clk:
clk_disable_unprepare(dwsmmio->clk);
+ reset_control_assert(dwsmmio->rstc);
+
return ret;
}
@@ -268,6 +280,7 @@ static int dw_spi_mmio_remove(struct platform_device *pdev)
pm_runtime_disable(&pdev->dev);
clk_disable_unprepare(dwsmmio->pclk);
clk_disable_unprepare(dwsmmio->clk);
+ reset_control_assert(dwsmmio->rstc);
return 0;
}