* [PATCH v2 0/2] mmc: sdhci-brcmstb: Add support for optional sdio_freq clock
@ 2022-05-17 18:04 ` Kamal Dasu
0 siblings, 0 replies; 10+ messages in thread
From: Kamal Dasu @ 2022-05-17 18:04 UTC (permalink / raw)
To: ulf.hansson, robh+dt, krzk+dt, alcooperx
Cc: f.fainelli, bcm-kernel-feedback-list, adrian.hunter, linux-mmc,
devicetree, linux-arm-kernel, Kamal Dasu
v2 changes :
- Added Reviewed-by tag to PATCH v2 1/2
- In PATCH v2 2/2 Used host->mmc->f_max instead of parsing the device
tree again, /s/clock-frequency/max-frequency in commit message
v1 Changes :
Sending the remaining 2 patches separately after implementing review comments
for the patches 3/4 and 4/4 as part of the following:
"mmc: sdhci-brcmstb: host controller clock enhancements"
https://lore.kernel.org/linux-arm-kernel/96fd3054-17b1-db42-9a44-a60485243807@linaro.org/t/
changes are rebased over
git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc.git refs/heads/next
tested brcm,sdhci-brcmstb.yaml and driver with and without sdio_freq clock.
Al Cooper (1):
mmc: sdhci-brcmstb: Add ability to increase max clock rate for 72116b0
Kamal Dasu (1):
dt-bindings: mmc: Add Broadcom optional sdio_freq clock
.../bindings/mmc/brcm,sdhci-brcmstb.yaml | 25 +++++++++++++----
drivers/mmc/host/sdhci-brcmstb.c | 28 +++++++++++++++++++
2 files changed, 47 insertions(+), 6 deletions(-)
--
2.17.1
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v2 0/2] mmc: sdhci-brcmstb: Add support for optional sdio_freq clock
@ 2022-05-17 18:04 ` Kamal Dasu
0 siblings, 0 replies; 10+ messages in thread
From: Kamal Dasu @ 2022-05-17 18:04 UTC (permalink / raw)
To: ulf.hansson, robh+dt, krzk+dt, alcooperx
Cc: f.fainelli, bcm-kernel-feedback-list, adrian.hunter, linux-mmc,
devicetree, linux-arm-kernel, Kamal Dasu
v2 changes :
- Added Reviewed-by tag to PATCH v2 1/2
- In PATCH v2 2/2 Used host->mmc->f_max instead of parsing the device
tree again, /s/clock-frequency/max-frequency in commit message
v1 Changes :
Sending the remaining 2 patches separately after implementing review comments
for the patches 3/4 and 4/4 as part of the following:
"mmc: sdhci-brcmstb: host controller clock enhancements"
https://lore.kernel.org/linux-arm-kernel/96fd3054-17b1-db42-9a44-a60485243807@linaro.org/t/
changes are rebased over
git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc.git refs/heads/next
tested brcm,sdhci-brcmstb.yaml and driver with and without sdio_freq clock.
Al Cooper (1):
mmc: sdhci-brcmstb: Add ability to increase max clock rate for 72116b0
Kamal Dasu (1):
dt-bindings: mmc: Add Broadcom optional sdio_freq clock
.../bindings/mmc/brcm,sdhci-brcmstb.yaml | 25 +++++++++++++----
drivers/mmc/host/sdhci-brcmstb.c | 28 +++++++++++++++++++
2 files changed, 47 insertions(+), 6 deletions(-)
--
2.17.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v2 1/2] dt-bindings: mmc: Add Broadcom optional sdio_freq clock
2022-05-17 18:04 ` Kamal Dasu
@ 2022-05-17 18:04 ` Kamal Dasu
-1 siblings, 0 replies; 10+ messages in thread
From: Kamal Dasu @ 2022-05-17 18:04 UTC (permalink / raw)
To: ulf.hansson, robh+dt, krzk+dt, alcooperx
Cc: f.fainelli, bcm-kernel-feedback-list, adrian.hunter, linux-mmc,
devicetree, linux-arm-kernel, Kamal Dasu
The 72116B0 has improved SDIO controllers that allow the max clock
rate to be increased from a max of 100MHz to a max of 150MHz.
Optional "sdio_freq" clock is used to drive the bus clock if present
optional property "max-frequency" specifies a base clock frequency
in Hz that overrides the base clock frequency in the CAPS registers.
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
.../bindings/mmc/brcm,sdhci-brcmstb.yaml | 25 ++++++++++++++-----
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/Documentation/devicetree/bindings/mmc/brcm,sdhci-brcmstb.yaml b/Documentation/devicetree/bindings/mmc/brcm,sdhci-brcmstb.yaml
index b672202fff4e..3a4f6e75bf5e 100644
--- a/Documentation/devicetree/bindings/mmc/brcm,sdhci-brcmstb.yaml
+++ b/Documentation/devicetree/bindings/mmc/brcm,sdhci-brcmstb.yaml
@@ -10,9 +10,6 @@ maintainers:
- Al Cooper <alcooperx@gmail.com>
- Florian Fainelli <f.fainelli@gmail.com>
-allOf:
- - $ref: mmc-controller.yaml#
-
properties:
compatible:
oneOf:
@@ -42,23 +39,39 @@ properties:
maxItems: 1
clocks:
- maxItems: 1
- description:
- handle to core clock for the sdhci controller.
+ minItems: 1
+ items:
+ - description: handle to core clock for the sdhci controller
+ - description: handle to improved 150Mhz clock for sdhci controller (Optional clock)
clock-names:
+ minItems: 1
items:
- const: sw_sdio
+ - const: sdio_freq # Optional clock
sdhci,auto-cmd12:
type: boolean
description: Specifies that controller should use auto CMD12
+allOf:
+ - $ref: mmc-controller.yaml#
+ - if:
+ properties:
+ clock-names:
+ contains:
+ const: sdio_freq
+
+ then:
+ required:
+ - max-frequency
+
required:
- compatible
- reg
- interrupts
- clocks
+ - clock-names
unevaluatedProperties: false
--
2.17.1
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v2 1/2] dt-bindings: mmc: Add Broadcom optional sdio_freq clock
@ 2022-05-17 18:04 ` Kamal Dasu
0 siblings, 0 replies; 10+ messages in thread
From: Kamal Dasu @ 2022-05-17 18:04 UTC (permalink / raw)
To: ulf.hansson, robh+dt, krzk+dt, alcooperx
Cc: f.fainelli, bcm-kernel-feedback-list, adrian.hunter, linux-mmc,
devicetree, linux-arm-kernel, Kamal Dasu
The 72116B0 has improved SDIO controllers that allow the max clock
rate to be increased from a max of 100MHz to a max of 150MHz.
Optional "sdio_freq" clock is used to drive the bus clock if present
optional property "max-frequency" specifies a base clock frequency
in Hz that overrides the base clock frequency in the CAPS registers.
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
.../bindings/mmc/brcm,sdhci-brcmstb.yaml | 25 ++++++++++++++-----
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/Documentation/devicetree/bindings/mmc/brcm,sdhci-brcmstb.yaml b/Documentation/devicetree/bindings/mmc/brcm,sdhci-brcmstb.yaml
index b672202fff4e..3a4f6e75bf5e 100644
--- a/Documentation/devicetree/bindings/mmc/brcm,sdhci-brcmstb.yaml
+++ b/Documentation/devicetree/bindings/mmc/brcm,sdhci-brcmstb.yaml
@@ -10,9 +10,6 @@ maintainers:
- Al Cooper <alcooperx@gmail.com>
- Florian Fainelli <f.fainelli@gmail.com>
-allOf:
- - $ref: mmc-controller.yaml#
-
properties:
compatible:
oneOf:
@@ -42,23 +39,39 @@ properties:
maxItems: 1
clocks:
- maxItems: 1
- description:
- handle to core clock for the sdhci controller.
+ minItems: 1
+ items:
+ - description: handle to core clock for the sdhci controller
+ - description: handle to improved 150Mhz clock for sdhci controller (Optional clock)
clock-names:
+ minItems: 1
items:
- const: sw_sdio
+ - const: sdio_freq # Optional clock
sdhci,auto-cmd12:
type: boolean
description: Specifies that controller should use auto CMD12
+allOf:
+ - $ref: mmc-controller.yaml#
+ - if:
+ properties:
+ clock-names:
+ contains:
+ const: sdio_freq
+
+ then:
+ required:
+ - max-frequency
+
required:
- compatible
- reg
- interrupts
- clocks
+ - clock-names
unevaluatedProperties: false
--
2.17.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v2 2/2] mmc: sdhci-brcmstb: Add ability to increase max clock rate for 72116b0
2022-05-17 18:04 ` Kamal Dasu
@ 2022-05-17 18:04 ` Kamal Dasu
-1 siblings, 0 replies; 10+ messages in thread
From: Kamal Dasu @ 2022-05-17 18:04 UTC (permalink / raw)
To: ulf.hansson, robh+dt, krzk+dt, alcooperx
Cc: f.fainelli, bcm-kernel-feedback-list, adrian.hunter, linux-mmc,
devicetree, linux-arm-kernel, Kamal Dasu
From: Al Cooper <alcooperx@gmail.com>
The 72116B0 has improved SDIO controllers that allow the max clock
rate to be increased from a max of 100MHz to a max of 150MHz. The
driver will need to get the clock and increase it's default rate
and override the caps register, that still indicates a max of 100MHz.
The new clock will be named "sdio_freq" in the DT node's "clock-names"
list. The driver will use a DT property, "max-frequency", to
enable this functionality and will get the actual rate in MHz
from the property to allow various speeds to be requested.
Signed-off-by: Al Cooper <alcooperx@gmail.com>
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
---
drivers/mmc/host/sdhci-brcmstb.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/drivers/mmc/host/sdhci-brcmstb.c b/drivers/mmc/host/sdhci-brcmstb.c
index 8eb57de48e0c..bb614a5e1ea4 100644
--- a/drivers/mmc/host/sdhci-brcmstb.c
+++ b/drivers/mmc/host/sdhci-brcmstb.c
@@ -250,6 +250,8 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev)
struct sdhci_pltfm_host *pltfm_host;
const struct of_device_id *match;
struct sdhci_brcmstb_priv *priv;
+ struct clk *master_clk;
+ u32 actual_clock_mhz;
struct sdhci_host *host;
struct resource *iomem;
struct clk *clk;
@@ -330,6 +332,32 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev)
if (match_priv->flags & BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT)
host->quirks |= SDHCI_QUIRK_BROKEN_TIMEOUT_VAL;
+ /* Change the base clock frequency if the DT property exists */
+ if (!(host->mmc->f_max))
+ goto add_host;
+
+ master_clk = devm_clk_get(&pdev->dev, "sdio_freq");
+ if (IS_ERR(master_clk)) {
+ dev_warn(&pdev->dev, "Clock for \"sdio_freq\" not found\n");
+ goto add_host;
+ } else {
+ res = clk_prepare_enable(master_clk);
+ if (res)
+ goto err;
+ }
+
+ /* set improved clock rate */
+ clk_set_rate(master_clk, host->mmc->f_max);
+ actual_clock_mhz = clk_get_rate(master_clk) / 1000000;
+
+ host->caps &= ~SDHCI_CLOCK_V3_BASE_MASK;
+ host->caps |= (actual_clock_mhz << SDHCI_CLOCK_BASE_SHIFT);
+ /* Disable presets because they are now incorrect */
+ host->quirks2 |= SDHCI_QUIRK2_PRESET_VALUE_BROKEN;
+ dev_dbg(&pdev->dev, "Base Clock Frequency changed to %dMHz\n",
+ actual_clock_mhz);
+
+add_host:
res = sdhci_brcmstb_add_host(host, priv);
if (res)
goto err;
--
2.17.1
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v2 2/2] mmc: sdhci-brcmstb: Add ability to increase max clock rate for 72116b0
@ 2022-05-17 18:04 ` Kamal Dasu
0 siblings, 0 replies; 10+ messages in thread
From: Kamal Dasu @ 2022-05-17 18:04 UTC (permalink / raw)
To: ulf.hansson, robh+dt, krzk+dt, alcooperx
Cc: f.fainelli, bcm-kernel-feedback-list, adrian.hunter, linux-mmc,
devicetree, linux-arm-kernel, Kamal Dasu
From: Al Cooper <alcooperx@gmail.com>
The 72116B0 has improved SDIO controllers that allow the max clock
rate to be increased from a max of 100MHz to a max of 150MHz. The
driver will need to get the clock and increase it's default rate
and override the caps register, that still indicates a max of 100MHz.
The new clock will be named "sdio_freq" in the DT node's "clock-names"
list. The driver will use a DT property, "max-frequency", to
enable this functionality and will get the actual rate in MHz
from the property to allow various speeds to be requested.
Signed-off-by: Al Cooper <alcooperx@gmail.com>
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
---
drivers/mmc/host/sdhci-brcmstb.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/drivers/mmc/host/sdhci-brcmstb.c b/drivers/mmc/host/sdhci-brcmstb.c
index 8eb57de48e0c..bb614a5e1ea4 100644
--- a/drivers/mmc/host/sdhci-brcmstb.c
+++ b/drivers/mmc/host/sdhci-brcmstb.c
@@ -250,6 +250,8 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev)
struct sdhci_pltfm_host *pltfm_host;
const struct of_device_id *match;
struct sdhci_brcmstb_priv *priv;
+ struct clk *master_clk;
+ u32 actual_clock_mhz;
struct sdhci_host *host;
struct resource *iomem;
struct clk *clk;
@@ -330,6 +332,32 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev)
if (match_priv->flags & BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT)
host->quirks |= SDHCI_QUIRK_BROKEN_TIMEOUT_VAL;
+ /* Change the base clock frequency if the DT property exists */
+ if (!(host->mmc->f_max))
+ goto add_host;
+
+ master_clk = devm_clk_get(&pdev->dev, "sdio_freq");
+ if (IS_ERR(master_clk)) {
+ dev_warn(&pdev->dev, "Clock for \"sdio_freq\" not found\n");
+ goto add_host;
+ } else {
+ res = clk_prepare_enable(master_clk);
+ if (res)
+ goto err;
+ }
+
+ /* set improved clock rate */
+ clk_set_rate(master_clk, host->mmc->f_max);
+ actual_clock_mhz = clk_get_rate(master_clk) / 1000000;
+
+ host->caps &= ~SDHCI_CLOCK_V3_BASE_MASK;
+ host->caps |= (actual_clock_mhz << SDHCI_CLOCK_BASE_SHIFT);
+ /* Disable presets because they are now incorrect */
+ host->quirks2 |= SDHCI_QUIRK2_PRESET_VALUE_BROKEN;
+ dev_dbg(&pdev->dev, "Base Clock Frequency changed to %dMHz\n",
+ actual_clock_mhz);
+
+add_host:
res = sdhci_brcmstb_add_host(host, priv);
if (res)
goto err;
--
2.17.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH v2 1/2] dt-bindings: mmc: Add Broadcom optional sdio_freq clock
2022-05-17 18:04 ` Kamal Dasu
@ 2022-05-17 18:31 ` Florian Fainelli
-1 siblings, 0 replies; 10+ messages in thread
From: Florian Fainelli @ 2022-05-17 18:31 UTC (permalink / raw)
To: Kamal Dasu, ulf.hansson, robh+dt, krzk+dt, alcooperx
Cc: bcm-kernel-feedback-list, adrian.hunter, linux-mmc, devicetree,
linux-arm-kernel
On 5/17/2022 11:04 AM, Kamal Dasu wrote:
> The 72116B0 has improved SDIO controllers that allow the max clock
> rate to be increased from a max of 100MHz to a max of 150MHz.
> Optional "sdio_freq" clock is used to drive the bus clock if present
> optional property "max-frequency" specifies a base clock frequency
> in Hz that overrides the base clock frequency in the CAPS registers.
>
> Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
--
Florian
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v2 1/2] dt-bindings: mmc: Add Broadcom optional sdio_freq clock
@ 2022-05-17 18:31 ` Florian Fainelli
0 siblings, 0 replies; 10+ messages in thread
From: Florian Fainelli @ 2022-05-17 18:31 UTC (permalink / raw)
To: Kamal Dasu, ulf.hansson, robh+dt, krzk+dt, alcooperx
Cc: bcm-kernel-feedback-list, adrian.hunter, linux-mmc, devicetree,
linux-arm-kernel
On 5/17/2022 11:04 AM, Kamal Dasu wrote:
> The 72116B0 has improved SDIO controllers that allow the max clock
> rate to be increased from a max of 100MHz to a max of 150MHz.
> Optional "sdio_freq" clock is used to drive the bus clock if present
> optional property "max-frequency" specifies a base clock frequency
> in Hz that overrides the base clock frequency in the CAPS registers.
>
> Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
--
Florian
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v2 2/2] mmc: sdhci-brcmstb: Add ability to increase max clock rate for 72116b0
2022-05-17 18:04 ` Kamal Dasu
@ 2022-05-17 20:29 ` Florian Fainelli
-1 siblings, 0 replies; 10+ messages in thread
From: Florian Fainelli @ 2022-05-17 20:29 UTC (permalink / raw)
To: Kamal Dasu, ulf.hansson, robh+dt, krzk+dt, alcooperx
Cc: bcm-kernel-feedback-list, adrian.hunter, linux-mmc, devicetree,
linux-arm-kernel
Hi Kamal,
On 5/17/2022 11:04 AM, Kamal Dasu wrote:
> From: Al Cooper <alcooperx@gmail.com>
>
> The 72116B0 has improved SDIO controllers that allow the max clock
> rate to be increased from a max of 100MHz to a max of 150MHz. The
> driver will need to get the clock and increase it's default rate
> and override the caps register, that still indicates a max of 100MHz.
> The new clock will be named "sdio_freq" in the DT node's "clock-names"
> list. The driver will use a DT property, "max-frequency", to
> enable this functionality and will get the actual rate in MHz
> from the property to allow various speeds to be requested.
>
> Signed-off-by: Al Cooper <alcooperx@gmail.com>
> Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
> ---
> drivers/mmc/host/sdhci-brcmstb.c | 28 ++++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-brcmstb.c b/drivers/mmc/host/sdhci-brcmstb.c
> index 8eb57de48e0c..bb614a5e1ea4 100644
> --- a/drivers/mmc/host/sdhci-brcmstb.c
> +++ b/drivers/mmc/host/sdhci-brcmstb.c
> @@ -250,6 +250,8 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev)
> struct sdhci_pltfm_host *pltfm_host;
> const struct of_device_id *match;
> struct sdhci_brcmstb_priv *priv;
> + struct clk *master_clk;
> + u32 actual_clock_mhz;
> struct sdhci_host *host;
> struct resource *iomem;
> struct clk *clk;
> @@ -330,6 +332,32 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev)
> if (match_priv->flags & BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT)
> host->quirks |= SDHCI_QUIRK_BROKEN_TIMEOUT_VAL;
>
> + /* Change the base clock frequency if the DT property exists */
> + if (!(host->mmc->f_max))
> + goto add_host;
> +
> + master_clk = devm_clk_get(&pdev->dev, "sdio_freq");
This looks like a candidate for devm_clk_get_optional() since the clock
is optional. Then you can call clk_prepare_enable() unconditionally even
if it is NULL/non-existent.
> + if (IS_ERR(master_clk)) {
> + dev_warn(&pdev->dev, "Clock for \"sdio_freq\" not found\n");
> + goto add_host;
> + } else {
> + res = clk_prepare_enable(master_clk);
> + if (res)
> + goto err;
It looks like we may be leaving the clock enabled even when we did not
want to (e.g.: error path) and do not we need to turn if off,
respectively turn it back on in .suspend() and .resume()?
> + }
> +
> + /* set improved clock rate */
> + clk_set_rate(master_clk, host->mmc->f_max);
> + actual_clock_mhz = clk_get_rate(master_clk) / 1000000;
> +
> + host->caps &= ~SDHCI_CLOCK_V3_BASE_MASK;
> + host->caps |= (actual_clock_mhz << SDHCI_CLOCK_BASE_SHIFT);
> + /* Disable presets because they are now incorrect */
> + host->quirks2 |= SDHCI_QUIRK2_PRESET_VALUE_BROKEN;
> + dev_dbg(&pdev->dev, "Base Clock Frequency changed to %dMHz\n",
> + actual_clock_mhz);
> +
> +add_host:
> res = sdhci_brcmstb_add_host(host, priv);
> if (res)
> goto err;
It looks like we would need to unwind the clk_prepare_enable(master_clk)
in case of failures here.
--
Florian
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v2 2/2] mmc: sdhci-brcmstb: Add ability to increase max clock rate for 72116b0
@ 2022-05-17 20:29 ` Florian Fainelli
0 siblings, 0 replies; 10+ messages in thread
From: Florian Fainelli @ 2022-05-17 20:29 UTC (permalink / raw)
To: Kamal Dasu, ulf.hansson, robh+dt, krzk+dt, alcooperx
Cc: bcm-kernel-feedback-list, adrian.hunter, linux-mmc, devicetree,
linux-arm-kernel
Hi Kamal,
On 5/17/2022 11:04 AM, Kamal Dasu wrote:
> From: Al Cooper <alcooperx@gmail.com>
>
> The 72116B0 has improved SDIO controllers that allow the max clock
> rate to be increased from a max of 100MHz to a max of 150MHz. The
> driver will need to get the clock and increase it's default rate
> and override the caps register, that still indicates a max of 100MHz.
> The new clock will be named "sdio_freq" in the DT node's "clock-names"
> list. The driver will use a DT property, "max-frequency", to
> enable this functionality and will get the actual rate in MHz
> from the property to allow various speeds to be requested.
>
> Signed-off-by: Al Cooper <alcooperx@gmail.com>
> Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
> ---
> drivers/mmc/host/sdhci-brcmstb.c | 28 ++++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-brcmstb.c b/drivers/mmc/host/sdhci-brcmstb.c
> index 8eb57de48e0c..bb614a5e1ea4 100644
> --- a/drivers/mmc/host/sdhci-brcmstb.c
> +++ b/drivers/mmc/host/sdhci-brcmstb.c
> @@ -250,6 +250,8 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev)
> struct sdhci_pltfm_host *pltfm_host;
> const struct of_device_id *match;
> struct sdhci_brcmstb_priv *priv;
> + struct clk *master_clk;
> + u32 actual_clock_mhz;
> struct sdhci_host *host;
> struct resource *iomem;
> struct clk *clk;
> @@ -330,6 +332,32 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev)
> if (match_priv->flags & BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT)
> host->quirks |= SDHCI_QUIRK_BROKEN_TIMEOUT_VAL;
>
> + /* Change the base clock frequency if the DT property exists */
> + if (!(host->mmc->f_max))
> + goto add_host;
> +
> + master_clk = devm_clk_get(&pdev->dev, "sdio_freq");
This looks like a candidate for devm_clk_get_optional() since the clock
is optional. Then you can call clk_prepare_enable() unconditionally even
if it is NULL/non-existent.
> + if (IS_ERR(master_clk)) {
> + dev_warn(&pdev->dev, "Clock for \"sdio_freq\" not found\n");
> + goto add_host;
> + } else {
> + res = clk_prepare_enable(master_clk);
> + if (res)
> + goto err;
It looks like we may be leaving the clock enabled even when we did not
want to (e.g.: error path) and do not we need to turn if off,
respectively turn it back on in .suspend() and .resume()?
> + }
> +
> + /* set improved clock rate */
> + clk_set_rate(master_clk, host->mmc->f_max);
> + actual_clock_mhz = clk_get_rate(master_clk) / 1000000;
> +
> + host->caps &= ~SDHCI_CLOCK_V3_BASE_MASK;
> + host->caps |= (actual_clock_mhz << SDHCI_CLOCK_BASE_SHIFT);
> + /* Disable presets because they are now incorrect */
> + host->quirks2 |= SDHCI_QUIRK2_PRESET_VALUE_BROKEN;
> + dev_dbg(&pdev->dev, "Base Clock Frequency changed to %dMHz\n",
> + actual_clock_mhz);
> +
> +add_host:
> res = sdhci_brcmstb_add_host(host, priv);
> if (res)
> goto err;
It looks like we would need to unwind the clk_prepare_enable(master_clk)
in case of failures here.
--
Florian
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^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2022-05-17 20:30 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-05-17 18:04 [PATCH v2 0/2] mmc: sdhci-brcmstb: Add support for optional sdio_freq clock Kamal Dasu
2022-05-17 18:04 ` Kamal Dasu
2022-05-17 18:04 ` [PATCH v2 1/2] dt-bindings: mmc: Add Broadcom " Kamal Dasu
2022-05-17 18:04 ` Kamal Dasu
2022-05-17 18:31 ` Florian Fainelli
2022-05-17 18:31 ` Florian Fainelli
2022-05-17 18:04 ` [PATCH v2 2/2] mmc: sdhci-brcmstb: Add ability to increase max clock rate for 72116b0 Kamal Dasu
2022-05-17 18:04 ` Kamal Dasu
2022-05-17 20:29 ` Florian Fainelli
2022-05-17 20:29 ` Florian Fainelli
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