[PATCHv2] mtd: nand: atmel_nand: retrieve NFC clock

Subsystems: memory technology devices (mtd), microchip nand driver, nand flash subsystem, open firmware and flattened device tree bindings, the rest

4 messages, 3 authors, 2014-09-12 · open the first message on its own page

[PATCHv2] mtd: nand: atmel_nand: retrieve NFC clock

From: Alexandre Belloni <hidden>
Date: 2014-09-11 17:52:39

From: Boris BREZILLON <redacted>

Signed-off-by: Boris BREZILLON <redacted>
Signed-off-by: Alexandre Belloni <redacted>
---

Changes in v2:
 - reworked the error path to really make the clock optional
 - Documented the new optional property

 .../devicetree/bindings/mtd/atmel-nand.txt         |  1 +
 drivers/mtd/nand/atmel_nand.c                      | 25 ++++++++++++++++++++++
 2 files changed, 26 insertions(+)
diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
index c4728839d0c1..f71e2ebab15b 100644
--- a/Documentation/devicetree/bindings/mtd/atmel-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
@@ -38,6 +38,7 @@ Optional properties:
             if don't want to use it.
   - Optional properties:
     - atmel,write-by-sram: boolean to enable NFC write by sram.
+    - clocks: phandle to the peripheral clock if it exists
 
 Examples:
 nand0: nand at 40000000,0 {
diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index 9c5f717bda54..69e0eb1ace54 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -27,6 +27,7 @@
  *
  */
 
+#include <linux/clk.h>
 #include <linux/dma-mapping.h>
 #include <linux/slab.h>
 #include <linux/module.h>
@@ -96,6 +97,8 @@ struct atmel_nfc {
 	bool			use_nfc_sram;
 	bool			write_by_sram;
 
+	struct clk		*clk;
+
 	bool			is_initialized;
 	struct completion	comp_ready;
 	struct completion	comp_cmd_done;
@@ -2248,6 +2251,7 @@ static int atmel_nand_nfc_probe(struct platform_device *pdev)
 {
 	struct atmel_nfc *nfc = &nand_nfc;
 	struct resource *nfc_cmd_regs, *nfc_hsmc_regs, *nfc_sram;
+	int ret;
 
 	nfc_cmd_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	nfc->base_cmd_regs = devm_ioremap_resource(&pdev->dev, nfc_cmd_regs);
@@ -2281,6 +2285,26 @@ static int atmel_nand_nfc_probe(struct platform_device *pdev)
 
 	nfc->is_initialized = true;
 	dev_info(&pdev->dev, "NFC is probed.\n");
+
+	nfc->clk = devm_clk_get(&pdev->dev, NULL);
+	if (!IS_ERR(nfc->clk)) {
+		ret = clk_prepare_enable(nfc->clk);
+		if (ret)
+			return ret;
+	} else {
+		dev_warn(&pdev->dev, "NFC clock is missing");
+	}
+
+	return 0;
+}
+
+static int atmel_nand_nfc_remove(struct platform_device *pdev)
+{
+	struct atmel_nfc *nfc = &nand_nfc;
+
+	if (!IS_ERR(nfc->clk))
+		clk_disable_unprepare(nfc->clk);
+
 	return 0;
 }
 
@@ -2297,6 +2321,7 @@ static struct platform_driver atmel_nand_nfc_driver = {
 		.of_match_table = of_match_ptr(atmel_nand_nfc_match),
 	},
 	.probe = atmel_nand_nfc_probe,
+	.remove = atmel_nand_nfc_remove,
 };
 
 static struct platform_driver atmel_nand_driver = {
-- 
1.9.1

Re: [PATCHv2] mtd: nand: atmel_nand: retrieve NFC clock

From: Nicolas Ferre <hidden>
Date: 2014-09-12 07:53:01

On 11/09/2014 19:52, Alexandre Belloni :
From: Boris BREZILLON <redacted>

Signed-off-by: Boris BREZILLON <redacted>
Signed-off-by: Alexandre Belloni <redacted>
You may need to add Josh Wu to the list because he is the "de-facto"
Maintainer of this driver.

Bye,
quoted hunk
---

Changes in v2:
 - reworked the error path to really make the clock optional
 - Documented the new optional property

 .../devicetree/bindings/mtd/atmel-nand.txt         |  1 +
 drivers/mtd/nand/atmel_nand.c                      | 25 ++++++++++++++++++++++
 2 files changed, 26 insertions(+)
diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
index c4728839d0c1..f71e2ebab15b 100644
--- a/Documentation/devicetree/bindings/mtd/atmel-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
@@ -38,6 +38,7 @@ Optional properties:
             if don't want to use it.
   - Optional properties:
     - atmel,write-by-sram: boolean to enable NFC write by sram.
+    - clocks: phandle to the peripheral clock if it exists
 
 Examples:
 nand0: nand at 40000000,0 {
diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index 9c5f717bda54..69e0eb1ace54 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -27,6 +27,7 @@
  *
  */
 
+#include <linux/clk.h>
 #include <linux/dma-mapping.h>
 #include <linux/slab.h>
 #include <linux/module.h>
@@ -96,6 +97,8 @@ struct atmel_nfc {
 	bool			use_nfc_sram;
 	bool			write_by_sram;
 
+	struct clk		*clk;
+
 	bool			is_initialized;
 	struct completion	comp_ready;
 	struct completion	comp_cmd_done;
@@ -2248,6 +2251,7 @@ static int atmel_nand_nfc_probe(struct platform_device *pdev)
 {
 	struct atmel_nfc *nfc = &nand_nfc;
 	struct resource *nfc_cmd_regs, *nfc_hsmc_regs, *nfc_sram;
+	int ret;
 
 	nfc_cmd_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	nfc->base_cmd_regs = devm_ioremap_resource(&pdev->dev, nfc_cmd_regs);
@@ -2281,6 +2285,26 @@ static int atmel_nand_nfc_probe(struct platform_device *pdev)
 
 	nfc->is_initialized = true;
 	dev_info(&pdev->dev, "NFC is probed.\n");
+
+	nfc->clk = devm_clk_get(&pdev->dev, NULL);
+	if (!IS_ERR(nfc->clk)) {
+		ret = clk_prepare_enable(nfc->clk);
+		if (ret)
+			return ret;
+	} else {
+		dev_warn(&pdev->dev, "NFC clock is missing");
+	}
+
+	return 0;
+}
+
+static int atmel_nand_nfc_remove(struct platform_device *pdev)
+{
+	struct atmel_nfc *nfc = &nand_nfc;
+
+	if (!IS_ERR(nfc->clk))
+		clk_disable_unprepare(nfc->clk);
+
 	return 0;
 }
 
@@ -2297,6 +2321,7 @@ static struct platform_driver atmel_nand_nfc_driver = {
 		.of_match_table = of_match_ptr(atmel_nand_nfc_match),
 	},
 	.probe = atmel_nand_nfc_probe,
+	.remove = atmel_nand_nfc_remove,
 };
 
 static struct platform_driver atmel_nand_driver = {

-- 
Nicolas Ferre

Re: [PATCHv2] mtd: nand: atmel_nand: retrieve NFC clock

From: Josh Wu <hidden>
Date: 2014-09-12 08:48:47

Hi, Nicolas

On 9/12/2014 3:52 PM, Nicolas Ferre wrote:
On 11/09/2014 19:52, Alexandre Belloni :
quoted
From: Boris BREZILLON <redacted>

Signed-off-by: Boris BREZILLON <redacted>
Signed-off-by: Alexandre Belloni <redacted>
You may need to add Josh Wu to the list because he is the "de-facto"
Maintainer of this driver.
Thanks for the email.
I almost miss it.

Best Regards,
Josh Wu
Bye,
quoted
---

Changes in v2:
  - reworked the error path to really make the clock optional
  - Documented the new optional property

  .../devicetree/bindings/mtd/atmel-nand.txt         |  1 +
  drivers/mtd/nand/atmel_nand.c                      | 25 ++++++++++++++++++++++
  2 files changed, 26 insertions(+)
diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
index c4728839d0c1..f71e2ebab15b 100644
--- a/Documentation/devicetree/bindings/mtd/atmel-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
@@ -38,6 +38,7 @@ Optional properties:
              if don't want to use it.
    - Optional properties:
      - atmel,write-by-sram: boolean to enable NFC write by sram.
+    - clocks: phandle to the peripheral clock if it exists
  
  Examples:
  nand0: nand at 40000000,0 {
diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index 9c5f717bda54..69e0eb1ace54 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -27,6 +27,7 @@
   *
   */
  
+#include <linux/clk.h>
  #include <linux/dma-mapping.h>
  #include <linux/slab.h>
  #include <linux/module.h>
@@ -96,6 +97,8 @@ struct atmel_nfc {
  	bool			use_nfc_sram;
  	bool			write_by_sram;
  
+	struct clk		*clk;
+
  	bool			is_initialized;
  	struct completion	comp_ready;
  	struct completion	comp_cmd_done;
@@ -2248,6 +2251,7 @@ static int atmel_nand_nfc_probe(struct platform_device *pdev)
  {
  	struct atmel_nfc *nfc = &nand_nfc;
  	struct resource *nfc_cmd_regs, *nfc_hsmc_regs, *nfc_sram;
+	int ret;
  
  	nfc_cmd_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	nfc->base_cmd_regs = devm_ioremap_resource(&pdev->dev, nfc_cmd_regs);
@@ -2281,6 +2285,26 @@ static int atmel_nand_nfc_probe(struct platform_device *pdev)
  
  	nfc->is_initialized = true;
  	dev_info(&pdev->dev, "NFC is probed.\n");
+
+	nfc->clk = devm_clk_get(&pdev->dev, NULL);
+	if (!IS_ERR(nfc->clk)) {
+		ret = clk_prepare_enable(nfc->clk);
+		if (ret)
+			return ret;
+	} else {
+		dev_warn(&pdev->dev, "NFC clock is missing");
+	}
+
+	return 0;
+}
+
+static int atmel_nand_nfc_remove(struct platform_device *pdev)
+{
+	struct atmel_nfc *nfc = &nand_nfc;
+
+	if (!IS_ERR(nfc->clk))
+		clk_disable_unprepare(nfc->clk);
+
  	return 0;
  }
  
@@ -2297,6 +2321,7 @@ static struct platform_driver atmel_nand_nfc_driver = {
  		.of_match_table = of_match_ptr(atmel_nand_nfc_match),
  	},
  	.probe = atmel_nand_nfc_probe,
+	.remove = atmel_nand_nfc_remove,
  };
  
  static struct platform_driver atmel_nand_driver = {

Re: [PATCHv2] mtd: nand: atmel_nand: retrieve NFC clock

From: Josh Wu <hidden>
Date: 2014-09-12 08:40:33

Hi, Alexandre

On 9/12/2014 1:52 AM, Alexandre Belloni wrote:
quoted hunk
From: Boris BREZILLON <redacted>

Signed-off-by: Boris BREZILLON <redacted>
Signed-off-by: Alexandre Belloni <redacted>
---

Changes in v2:
  - reworked the error path to really make the clock optional
  - Documented the new optional property

  .../devicetree/bindings/mtd/atmel-nand.txt         |  1 +
  drivers/mtd/nand/atmel_nand.c                      | 25 ++++++++++++++++++++++
  2 files changed, 26 insertions(+)
diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
index c4728839d0c1..f71e2ebab15b 100644
--- a/Documentation/devicetree/bindings/mtd/atmel-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
@@ -38,6 +38,7 @@ Optional properties:
              if don't want to use it.
    - Optional properties:
      - atmel,write-by-sram: boolean to enable NFC write by sram.
+    - clocks: phandle to the peripheral clock if it exists
  
  Examples:
  nand0: nand at 40000000,0 {
diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index 9c5f717bda54..69e0eb1ace54 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -27,6 +27,7 @@
   *
   */
  
+#include <linux/clk.h>
  #include <linux/dma-mapping.h>
  #include <linux/slab.h>
  #include <linux/module.h>
@@ -96,6 +97,8 @@ struct atmel_nfc {
  	bool			use_nfc_sram;
  	bool			write_by_sram;
  
+	struct clk		*clk;
+
  	bool			is_initialized;
  	struct completion	comp_ready;
  	struct completion	comp_cmd_done;
@@ -2248,6 +2251,7 @@ static int atmel_nand_nfc_probe(struct platform_device *pdev)
  {
  	struct atmel_nfc *nfc = &nand_nfc;
  	struct resource *nfc_cmd_regs, *nfc_hsmc_regs, *nfc_sram;
+	int ret;
  
  	nfc_cmd_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	nfc->base_cmd_regs = devm_ioremap_resource(&pdev->dev, nfc_cmd_regs);
@@ -2281,6 +2285,26 @@ static int atmel_nand_nfc_probe(struct platform_device *pdev)
  
  	nfc->is_initialized = true;
  	dev_info(&pdev->dev, "NFC is probed.\n");
+
+	nfc->clk = devm_clk_get(&pdev->dev, NULL);
+	if (!IS_ERR(nfc->clk)) {
+		ret = clk_prepare_enable(nfc->clk);
+		if (ret)
+			return ret;
In this case, the NFC clock is not enabled, so I think 
nfc->is_initialized should set to false.
Otherwise, the nand driver will try to use the NFC without enabled the 
clock.

Is it better to move the code block

    nfc->is_initialized = true;
    dev_info(&pdev->dev, "NFC is probed.\n");

to just before the:

    return 0;


Best Regards,
Josh Wu
quoted hunk
+	} else {
+		dev_warn(&pdev->dev, "NFC clock is missing");
+	}
+
+	return 0;
+}
+
+static int atmel_nand_nfc_remove(struct platform_device *pdev)
+{
+	struct atmel_nfc *nfc = &nand_nfc;
+
+	if (!IS_ERR(nfc->clk))
+		clk_disable_unprepare(nfc->clk);
+
  	return 0;
  }
  
@@ -2297,6 +2321,7 @@ static struct platform_driver atmel_nand_nfc_driver = {
  		.of_match_table = of_match_ptr(atmel_nand_nfc_match),
  	},
  	.probe = atmel_nand_nfc_probe,
+	.remove = atmel_nand_nfc_remove,
  };
  
  static struct platform_driver atmel_nand_driver = {
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