* [PATCHv2 1/2] spi: dw: add reset control
@ 2020-05-26 15:12 Dinh Nguyen
2020-05-26 15:12 ` [PATCHv2 2/2] dt-bindings: snps,dw-apb-ssi: add optional reset property Dinh Nguyen
2020-05-26 15:21 ` [PATCHv2 1/2] spi: dw: add reset control Andy Shevchenko
0 siblings, 2 replies; 3+ messages in thread
From: Dinh Nguyen @ 2020-05-26 15:12 UTC (permalink / raw)
To: linux-kernel
Cc: dinguyen, devicetree, broonie, robh+dt, linux-spi, Sergey.Semin,
fancer.lancer, andriy.shevchenko, lars.povlsen, Liang Jin J
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>
---
v2: use _get_optional_exclusive
put IP back into reset if there was an error in probe function
---
drivers/spi/spi-dw-mmio.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c
index 384a3ab6dc2d..07e015b6d03d 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
@@ -175,6 +177,14 @@ 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)) {
+ if (PTR_ERR(dwsmmio->rstc) == -EPROBE_DEFER)
+ return PTR_ERR(dwsmmio->rstc);
+ }
+ reset_control_deassert(dwsmmio->rstc);
+
dws->bus_num = pdev->id;
dws->max_freq = clk_get_rate(dwsmmio->clk);
@@ -208,6 +218,8 @@ static int dw_spi_mmio_probe(struct platform_device *pdev)
clk_disable_unprepare(dwsmmio->pclk);
out_clk:
clk_disable_unprepare(dwsmmio->clk);
+ reset_control_assert(dwsmmio->rstc);
+
return ret;
}
@@ -219,6 +231,7 @@ 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;
}
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCHv2 2/2] dt-bindings: snps,dw-apb-ssi: add optional reset property
2020-05-26 15:12 [PATCHv2 1/2] spi: dw: add reset control Dinh Nguyen
@ 2020-05-26 15:12 ` Dinh Nguyen
2020-05-26 15:21 ` [PATCHv2 1/2] spi: dw: add reset control Andy Shevchenko
1 sibling, 0 replies; 3+ messages in thread
From: Dinh Nguyen @ 2020-05-26 15:12 UTC (permalink / raw)
To: linux-kernel
Cc: dinguyen, devicetree, broonie, robh+dt, linux-spi, Sergey.Semin,
fancer.lancer, andriy.shevchenko, lars.povlsen
Add optional reset property.
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
---
v2: actually document the "resets" and "reset-names" optional properties
---
Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt
index 3ed08ee9feba..c679778612f3 100644
--- a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt
+++ b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt
@@ -22,6 +22,9 @@ Optional properties:
- num-cs : The number of chipselects. If omitted, this will default to 4.
- reg-io-width : The I/O register width (in bytes) implemented by this
device. Supported values are 2 or 4 (the default).
+- resets : contains an entry for each entry in reset-names.
+ See ../reset/reset.txt for details.
+- reset-names : must contain "spi"
Child nodes as per the generic SPI binding.
@@ -37,5 +40,7 @@ Example:
num-cs = <2>;
cs-gpios = <&gpio0 13 0>,
<&gpio0 14 0>;
+ resets = <&rst SPIM0_RST>;
+ reset-names = "spi";
};
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCHv2 1/2] spi: dw: add reset control
2020-05-26 15:12 [PATCHv2 1/2] spi: dw: add reset control Dinh Nguyen
2020-05-26 15:12 ` [PATCHv2 2/2] dt-bindings: snps,dw-apb-ssi: add optional reset property Dinh Nguyen
@ 2020-05-26 15:21 ` Andy Shevchenko
1 sibling, 0 replies; 3+ messages in thread
From: Andy Shevchenko @ 2020-05-26 15:21 UTC (permalink / raw)
To: Dinh Nguyen
Cc: linux-kernel, devicetree, broonie, robh+dt, linux-spi,
Sergey.Semin, fancer.lancer, lars.povlsen, Liang Jin J
On Tue, May 26, 2020 at 10:12:17AM -0500, Dinh Nguyen wrote:
> Add mechanism to get the reset control and deassert it in order to bring
> the IP out of reset.
...
> struct clk *clk;
> struct clk *pclk;
> void *priv;
> + struct reset_control *rstc;
I think either you make it one space or you align all the rest members
accordingly. I would rather go with former.
...
> + /* find an optional reset controller */
> + dwsmmio->rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, "spi");
> + if (IS_ERR(dwsmmio->rstc)) {
> + if (PTR_ERR(dwsmmio->rstc) == -EPROBE_DEFER)
> + return PTR_ERR(dwsmmio->rstc);
If it's other type of errors when reset control, we ignore them...
Why?!
> + }
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 3+ messages in thread
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2020-05-26 15:12 [PATCHv2 1/2] spi: dw: add reset control Dinh Nguyen
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2020-05-26 15:21 ` [PATCHv2 1/2] spi: dw: add reset control Andy Shevchenko
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