2019-05-10 14:27:09

by Yannick FERTRE

[permalink] [raw]
Subject: [PATCH v2 2/3] drm/stm: dsi: add support of an optional regulator

Add support of an optional regulator for the phy part of the DSI
controller.

Signed-off-by: Yannick Fertré <[email protected]>
---
drivers/gpu/drm/stm/dw_mipi_dsi-stm.c | 45 ++++++++++++++++++++++++++++++-----
1 file changed, 39 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
index 1bef73e..22bd095 100644
--- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
+++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
@@ -9,6 +9,7 @@
#include <linux/clk.h>
#include <linux/iopoll.h>
#include <linux/module.h>
+#include <linux/regulator/consumer.h>
#include <drm/drmP.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/bridge/dw_mipi_dsi.h>
@@ -76,6 +77,7 @@ struct dw_mipi_dsi_stm {
u32 hw_version;
int lane_min_kbps;
int lane_max_kbps;
+ struct regulator *vdd_supply;
};

static inline void dsi_write(struct dw_mipi_dsi_stm *dsi, u32 reg, u32 val)
@@ -318,17 +320,31 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
return PTR_ERR(dsi->base);
}

+ dsi->vdd_supply = devm_regulator_get_optional(dev, "phy-dsi");
+ if (IS_ERR(dsi->vdd_supply)) {
+ ret = PTR_ERR(dsi->vdd_supply);
+ if (ret != -EPROBE_DEFER)
+ DRM_ERROR("failed to request regulator: %d\n", ret);
+ return ret;
+ }
+
+ ret = regulator_enable(dsi->vdd_supply);
+ if (ret) {
+ DRM_ERROR("failed to enable regulator: %d\n", ret);
+ return ret;
+ }
+
dsi->pllref_clk = devm_clk_get(dev, "ref");
if (IS_ERR(dsi->pllref_clk)) {
ret = PTR_ERR(dsi->pllref_clk);
- dev_err(dev, "Unable to get pll reference clock: %d\n", ret);
- return ret;
+ DRM_ERROR("Unable to get pll reference clock: %d\n", ret);
+ goto err_clk_get;
}

ret = clk_prepare_enable(dsi->pllref_clk);
if (ret) {
- dev_err(dev, "%s: Failed to enable pllref_clk\n", __func__);
- return ret;
+ DRM_ERROR("%s: Failed to enable pllref_clk\n", __func__);
+ goto err_clk_get;
}

dw_mipi_dsi_stm_plat_data.base = dsi->base;
@@ -339,11 +355,19 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
if (IS_ERR(dsi->dsi)) {
DRM_ERROR("Failed to initialize mipi dsi host\n");
- clk_disable_unprepare(dsi->pllref_clk);
- return PTR_ERR(dsi->dsi);
+ ret = PTR_ERR(dsi->dsi);
+ goto err_dsi_probe;
}

return 0;
+
+err_dsi_probe:
+ clk_disable_unprepare(dsi->pllref_clk);
+err_clk_get:
+ regulator_disable(dsi->vdd_supply);
+
+ return ret;
+
}

static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
@@ -351,6 +375,7 @@ static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev);

clk_disable_unprepare(dsi->pllref_clk);
+ regulator_disable(dsi->vdd_supply);
dw_mipi_dsi_remove(dsi->dsi);

return 0;
@@ -363,6 +388,7 @@ static int __maybe_unused dw_mipi_dsi_stm_suspend(struct device *dev)
DRM_DEBUG_DRIVER("\n");

clk_disable_unprepare(dsi->pllref_clk);
+ regulator_disable(dsi->vdd_supply);

return 0;
}
@@ -370,9 +396,16 @@ static int __maybe_unused dw_mipi_dsi_stm_suspend(struct device *dev)
static int __maybe_unused dw_mipi_dsi_stm_resume(struct device *dev)
{
struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
+ int ret;

DRM_DEBUG_DRIVER("\n");

+ ret = regulator_enable(dsi->vdd_supply);
+ if (ret) {
+ DRM_ERROR("failed to enable regulator: %d\n", ret);
+ return ret;
+ }
+
clk_prepare_enable(dsi->pllref_clk);

return 0;
--
2.7.4


2019-05-10 16:17:44

by Philippe Cornu

[permalink] [raw]
Subject: Re: [PATCH v2 2/3] drm/stm: dsi: add support of an optional regulator

Dear Yannick,
Thank you for your patch,

I like better the new shorter commit heading, thank you.


On 5/10/19 4:20 PM, Yannick Fertré wrote:
> Add support of an optional regulator for the phy part of the DSI
> controller.
>
> Signed-off-by: Yannick Fertré <[email protected]>
> ---
> drivers/gpu/drm/stm/dw_mipi_dsi-stm.c | 45 ++++++++++++++++++++++++++++++-----
> 1 file changed, 39 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> index 1bef73e..22bd095 100644
> --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> @@ -9,6 +9,7 @@
> #include <linux/clk.h>
> #include <linux/iopoll.h>
> #include <linux/module.h>
> +#include <linux/regulator/consumer.h>
> #include <drm/drmP.h>
> #include <drm/drm_mipi_dsi.h>
> #include <drm/bridge/dw_mipi_dsi.h>
> @@ -76,6 +77,7 @@ struct dw_mipi_dsi_stm {
> u32 hw_version;
> int lane_min_kbps;
> int lane_max_kbps;
> + struct regulator *vdd_supply;
> };
>
> static inline void dsi_write(struct dw_mipi_dsi_stm *dsi, u32 reg, u32 val)
> @@ -318,17 +320,31 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
> return PTR_ERR(dsi->base);
> }
>
> + dsi->vdd_supply = devm_regulator_get_optional(dev, "phy-dsi");
> + if (IS_ERR(dsi->vdd_supply)) {
> + ret = PTR_ERR(dsi->vdd_supply);
> + if (ret != -EPROBE_DEFER)
> + DRM_ERROR("failed to request regulator: %d\n", ret);
> + return ret;
> + }
> +
> + ret = regulator_enable(dsi->vdd_supply);
> + if (ret) {
> + DRM_ERROR("failed to enable regulator: %d\n", ret);
> + return ret;
> + }
> +
> dsi->pllref_clk = devm_clk_get(dev, "ref");
> if (IS_ERR(dsi->pllref_clk)) {
> ret = PTR_ERR(dsi->pllref_clk);
> - dev_err(dev, "Unable to get pll reference clock: %d\n", ret);
> - return ret;
> + DRM_ERROR("Unable to get pll reference clock: %d\n", ret);
> + goto err_clk_get;
> }
>
> ret = clk_prepare_enable(dsi->pllref_clk);
> if (ret) {
> - dev_err(dev, "%s: Failed to enable pllref_clk\n", __func__);
> - return ret;
> + DRM_ERROR("%s: Failed to enable pllref_clk\n", __func__);
> + goto err_clk_get;
> }
>
> dw_mipi_dsi_stm_plat_data.base = dsi->base;
> @@ -339,11 +355,19 @@ static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
> dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
> if (IS_ERR(dsi->dsi)) {
> DRM_ERROR("Failed to initialize mipi dsi host\n");
> - clk_disable_unprepare(dsi->pllref_clk);
> - return PTR_ERR(dsi->dsi);
> + ret = PTR_ERR(dsi->dsi);
> + goto err_dsi_probe;
> }
>
> return 0;
> +
> +err_dsi_probe:
> + clk_disable_unprepare(dsi->pllref_clk);
> +err_clk_get:
> + regulator_disable(dsi->vdd_supply);
> +
> + return ret;
> +
> }
>
> static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
> @@ -351,6 +375,7 @@ static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
> struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev);
>
> clk_disable_unprepare(dsi->pllref_clk);
> + regulator_disable(dsi->vdd_supply);
> dw_mipi_dsi_remove(dsi->dsi);

for a future patch: we may have a different order
dw_mipi_dsi_remove(dsi->dsi);
clk_disable_unprepare(dsi->pllref_clk);
regulator_disable(dsi->vdd_supply);

>
> return 0;
> @@ -363,6 +388,7 @@ static int __maybe_unused dw_mipi_dsi_stm_suspend(struct device *dev)
> DRM_DEBUG_DRIVER("\n");
>
> clk_disable_unprepare(dsi->pllref_clk);
> + regulator_disable(dsi->vdd_supply);
>
> return 0;
> }
> @@ -370,9 +396,16 @@ static int __maybe_unused dw_mipi_dsi_stm_suspend(struct device *dev)
> static int __maybe_unudw_mipi_dsi_remove(dsi->dsi);sed dw_mipi_dsi_stm_resume(struct device *dev)
> {
> struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
> + int ret;
>
> DRM_DEBUG_DRIVER("\n");
>
> + ret = regulator_enable(dsi->vdd_supply);
> + if (ret) {
> + DRM_ERROR("failed to enable regulator: %d\n", ret);
> + return ret;
> + }
> +
> clk_prepare_enable(dsi->pllref_clk);

for a future patch: we may check clk_prepare_enable return value.

>
> return 0;
>


Acked-by: Philippe Cornu <[email protected]>

Philippe :)

2019-05-13 13:13:59

by Philippe Cornu

[permalink] [raw]
Subject: Re: [PATCH v2 2/3] drm/stm: dsi: add support of an optional regulator

Hi Yannick,


On 5/10/19 6:16 PM, Philippe Cornu wrote:
> Dear Yannick,
> Thank you for your patch,
>
> I like better the new shorter commit heading, thank you.
>
>
> On 5/10/19 4:20 PM, Yannick Fertré wrote:
>> Add support of an optional regulator for the phy part of the DSI
>> controller.
>>
>> Signed-off-by: Yannick Fertré <[email protected]>
>> ---
>>   drivers/gpu/drm/stm/dw_mipi_dsi-stm.c | 45
>> ++++++++++++++++++++++++++++++-----
>>   1 file changed, 39 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
>> b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
>> index 1bef73e..22bd095 100644
>> --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
>> +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
>> @@ -9,6 +9,7 @@
>>   #include <linux/clk.h>
>>   #include <linux/iopoll.h>
>>   #include <linux/module.h>
>> +#include <linux/regulator/consumer.h>
>>   #include <drm/drmP.h>
>>   #include <drm/drm_mipi_dsi.h>
>>   #include <drm/bridge/dw_mipi_dsi.h>
>> @@ -76,6 +77,7 @@ struct dw_mipi_dsi_stm {
>>       u32 hw_version;
>>       int lane_min_kbps;
>>       int lane_max_kbps;
>> +    struct regulator *vdd_supply;
>>   };
>>   static inline void dsi_write(struct dw_mipi_dsi_stm *dsi, u32 reg,
>> u32 val)
>> @@ -318,17 +320,31 @@ static int dw_mipi_dsi_stm_probe(struct
>> platform_device *pdev)
>>           return PTR_ERR(dsi->base);
>>       }
>> +    dsi->vdd_supply = devm_regulator_get_optional(dev, "phy-dsi");
>> +    if (IS_ERR(dsi->vdd_supply)) {
>> +        ret = PTR_ERR(dsi->vdd_supply);
>> +        if (ret != -EPROBE_DEFER)
>> +            DRM_ERROR("failed to request regulator: %d\n", ret);
>> +        return ret;
>> +    }


I did more tests on a stm32f469 disco board and this above code does not
work (the ret value is -ENODEV)

Two possibilities then:
1) remove the _optional (but we have the "using dummy regulator"
message, I am fine with it)

or
2) handle -ENODEV but do not forget to check vdd_supply!=NULL before
calling all regulator_(enable/disable)

if (ret != -ENODEV) {
if (ret != -EPROBE_DEFER)
DRM_ERROR("failed to request regulator: %d\n",
ret);
return ret;
}
dsi->vdd_supply = NULL;
}

if (dsi->vdd_supply) {
ret = regulator_enable(dsi->vdd_supply);
...


if (dsi->vdd_supply)
regulator_disable(dsi->vdd_supply);


I let you choose your favorite one.

Thank you,
Philippe

>> +
>> +    ret = regulator_enable(dsi->vdd_supply);
>> +    if (ret) {
>> +        DRM_ERROR("failed to enable regulator: %d\n", ret);
>> +        return ret;
>> +    }
>> +
>>       dsi->pllref_clk = devm_clk_get(dev, "ref");
>>       if (IS_ERR(dsi->pllref_clk)) {
>>           ret = PTR_ERR(dsi->pllref_clk);
>> -        dev_err(dev, "Unable to get pll reference clock: %d\n", ret);
>> -        return ret;
>> +        DRM_ERROR("Unable to get pll reference clock: %d\n", ret);
>> +        goto err_clk_get;
>>       }
>>       ret = clk_prepare_enable(dsi->pllref_clk);
>>       if (ret) {
>> -        dev_err(dev, "%s: Failed to enable pllref_clk\n", __func__);
>> -        return ret;
>> +        DRM_ERROR("%s: Failed to enable pllref_clk\n", __func__);
>> +        goto err_clk_get;
>>       }
>>       dw_mipi_dsi_stm_plat_data.base = dsi->base;
>> @@ -339,11 +355,19 @@ static int dw_mipi_dsi_stm_probe(struct
>> platform_device *pdev)
>>       dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
>>       if (IS_ERR(dsi->dsi)) {
>>           DRM_ERROR("Failed to initialize mipi dsi host\n");
>> -        clk_disable_unprepare(dsi->pllref_clk);
>> -        return PTR_ERR(dsi->dsi);
>> +        ret = PTR_ERR(dsi->dsi);
>> +        goto err_dsi_probe;
>>       }
>>       return 0;
>> +
>> +err_dsi_probe:
>> +    clk_disable_unprepare(dsi->pllref_clk);
>> +err_clk_get:
>> +    regulator_disable(dsi->vdd_supply);
>> +
>> +    return ret;
>> +
>>   }
>>   static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
>> @@ -351,6 +375,7 @@ static int dw_mipi_dsi_stm_remove(struct
>> platform_device *pdev)
>>       struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev);
>>       clk_disable_unprepare(dsi->pllref_clk);
>> +    regulator_disable(dsi->vdd_supply);
>>       dw_mipi_dsi_remove(dsi->dsi);
>
> for a future patch: we may have a different order
>     dw_mipi_dsi_remove(dsi->dsi);
>     clk_disable_unprepare(dsi->pllref_clk);
>     regulator_disable(dsi->vdd_supply);
>
>>       return 0;
>> @@ -363,6 +388,7 @@ static int __maybe_unused
>> dw_mipi_dsi_stm_suspend(struct device *dev)
>>       DRM_DEBUG_DRIVER("\n");
>>       clk_disable_unprepare(dsi->pllref_clk);
>> +    regulator_disable(dsi->vdd_supply);
>>       return 0;
>>   }
>> @@ -370,9 +396,16 @@ static int __maybe_unused
>> dw_mipi_dsi_stm_suspend(struct device *dev)
>>   static int __maybe_unudw_mipi_dsi_remove(dsi->dsi);sed
>> dw_mipi_dsi_stm_resume(struct device *dev)
>>   {
>>       struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
>> +    int ret;
>>       DRM_DEBUG_DRIVER("\n");
>> +    ret = regulator_enable(dsi->vdd_supply);
>> +    if (ret) {
>> +        DRM_ERROR("failed to enable regulator: %d\n", ret);
>> +        return ret;
>> +    }
>> +
>>       clk_prepare_enable(dsi->pllref_clk);
>
> for a future patch: we may check clk_prepare_enable return value.
>
>>       return 0;
>>
>
>
> Acked-by: Philippe Cornu <[email protected]>
>
> Philippe :)
>