[PATCH v4 0/6] K2G: Add QSPI support

[PATCH v4 0/6] K2G: Add QSPI support

[Vignesh R]

This series adds support for Cadence QSPI IP present in TI's 66AK2G SoC.
The patches enhance the existing cadence-quadspi driver to support
loopback clock circuit, pm_runtime support and tweaks for 66AK2G SoC.

Change log:

v4:
* New patch to fix error handling sequence in probe.

v3:
* Fix build warnings reported by kbuild test bot.

Resend:
* Rebase to latest linux-next.
* Collect Acked-bys

v2:
* Drop DT patches. Will be sent as separate series as requested by
 maintainer.
* Split binding docs into separate patches.
* Address comments by Rob Herring.

Vignesh R (6):
  mtd: spi-nor: cadence-quadspi: Add TI 66AK2G SoC specific compatible
  mtd: spi-nor: cadence-quadspi: add a delay in write sequence
  mtd: spi-nor: cadence-quadspi: Add new binding to enable loop-back
    circuit
  mtd: spi-nor: cadence-quadspi: Add support to enable loop-back clock
    circuit
  mtd: spi-nor: cadence-quadspi: Fix error path in probe
  mtd: spi-nor: cadence-quadspi: Add runtime PM support

 .../devicetree/bindings/mtd/cadence-quadspi.txt    |  7 ++-
 drivers/mtd/spi-nor/cadence-quadspi.c              | 55 +++++++++++++++++++---
 2 files changed, 55 insertions(+), 7 deletions(-)

-- 
2.14.1

[PATCH v4 1/6] mtd: spi-nor: cadence-quadspi: Add TI 66AK2G SoC specific compatible

[Vignesh R]

Update binding documentation to add a new compatible for TI 66AK2G SoC,
to handle TI SoC specific quirks in the driver.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/mtd/cadence-quadspi.txt | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt b/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt
index f248056da24c..7dbe3bd9ac56 100644
--- a/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt
+++ b/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt
@@ -1,7 +1,9 @@
 * Cadence Quad SPI controller
 
 Required properties:
-- compatible : Should be "cdns,qspi-nor".
+- compatible : should be one of the following:
+	Generic default - "cdns,qspi-nor".
+	For TI 66AK2G SoC - "ti,k2g-qspi", "cdns,qspi-nor".
 - reg : Contains two entries, each of which is a tuple consisting of a
 	physical address and length. The first entry is the address and
 	length of the controller register set. The second entry is the
-- 
2.14.1

[PATCH v4 2/6] mtd: spi-nor: cadence-quadspi: add a delay in write sequence

[Vignesh R]

As per 66AK2G02 TRM[1] SPRUHY8F section 11.15.5.3 Indirect Access
Controller programming sequence, a delay equal to couple of QSPI master
clock(~5ns) is required after setting CQSPI_REG_INDIRECTWR_START bit and
writing data to the flash. Introduce a quirk flag CQSPI_NEEDS_WR_DELAY
to handle this and set this flag for TI 66AK2G SoC.

[1]http://www.ti.com/lit/ug/spruhy8f/spruhy8f.pdf

Signed-off-by: Vignesh R <vigneshr@ti.com>
---
 drivers/mtd/spi-nor/cadence-quadspi.c | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
index 53c7d8e0327a..5cd5d6f7303f 100644
--- a/drivers/mtd/spi-nor/cadence-quadspi.c
+++ b/drivers/mtd/spi-nor/cadence-quadspi.c
@@ -38,6 +38,9 @@
 #define CQSPI_NAME			"cadence-qspi"
 #define CQSPI_MAX_CHIPSELECT		16
 
+/* Quirks */
+#define CQSPI_NEEDS_WR_DELAY		BIT(0)
+
 struct cqspi_st;
 
 struct cqspi_flash_pdata {
@@ -76,6 +79,7 @@ struct cqspi_st {
 	u32			fifo_depth;
 	u32			fifo_width;
 	u32			trigger_address;
+	u32			wr_delay;
 	struct cqspi_flash_pdata f_pdata[CQSPI_MAX_CHIPSELECT];
 };
 
@@ -608,6 +612,15 @@ static int cqspi_indirect_write_execute(struct spi_nor *nor,
 	reinit_completion(&cqspi->transfer_complete);
 	writel(CQSPI_REG_INDIRECTWR_START_MASK,
 	       reg_base + CQSPI_REG_INDIRECTWR);
+	/*
+	 * As per 66AK2G02 TRM SPRUHY8F section 11.15.5.3 Indirect Access
+	 * Controller programming sequence, couple of cycles of
+	 * QSPI_REF_CLK delay is required for the above bit to
+	 * be internally synchronized by the QSPI module. Provide 5
+	 * cycles of delay.
+	 */
+	if (cqspi->wr_delay)
+		ndelay(cqspi->wr_delay);
 
 	while (remaining > 0) {
 		write_bytes = remaining > page_size ? page_size : remaining;
@@ -1156,6 +1169,7 @@ static int cqspi_probe(struct platform_device *pdev)
 	struct cqspi_st *cqspi;
 	struct resource *res;
 	struct resource *res_ahb;
+	unsigned long data;
 	int ret;
 	int irq;
 
@@ -1213,6 +1227,10 @@ static int cqspi_probe(struct platform_device *pdev)
 	}
 
 	cqspi->master_ref_clk_hz = clk_get_rate(cqspi->clk);
+	data  = (unsigned long)of_device_get_match_data(dev);
+	if (data & CQSPI_NEEDS_WR_DELAY)
+		cqspi->wr_delay = 5 * DIV_ROUND_UP(NSEC_PER_SEC,
+						   cqspi->master_ref_clk_hz);
 
 	ret = devm_request_irq(dev, irq, cqspi_irq_handler, 0,
 			       pdev->name, cqspi);
@@ -1284,7 +1302,14 @@ static const struct dev_pm_ops cqspi__dev_pm_ops = {
 #endif
 
 static const struct of_device_id cqspi_dt_ids[] = {
-	{.compatible = "cdns,qspi-nor",},
+	{
+		.compatible = "cdns,qspi-nor",
+		.data = (void *)0,
+	},
+	{
+		.compatible = "ti,k2g-qspi",
+		.data = (void *)CQSPI_NEEDS_WR_DELAY,
+	},
 	{ /* end of table */ }
 };
 
-- 
2.14.1

[PATCH v4 3/6] mtd: spi-nor: cadence-quadspi: Add new binding to enable loop-back circuit

[Vignesh R]

Cadence QSPI IP has a adapted loop-back circuit which can be enabled by
setting BYPASS field to 0 in READCAPTURE register. It enables use of
QSPI return clock to latch the data rather than the internal QSPI
reference clock. For high speed operations, adapted loop-back circuit
using QSPI return clock helps to increase data valid window.

Add DT parameter cdns,rclk-en to help enable adapted loop-back circuit
for boards which do have QSPI return clock provided. Update binding
documentation for the same.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/mtd/cadence-quadspi.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt b/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt
index 7dbe3bd9ac56..bb2075df9b38 100644
--- a/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt
+++ b/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt
@@ -16,6 +16,9 @@ Required properties:
 
 Optional properties:
 - cdns,is-decoded-cs : Flag to indicate whether decoder is used or not.
+- cdns,rclk-en : Flag to indicate that QSPI return clock is used to latch
+  the read data rather than the QSPI clock. Make sure that QSPI return
+  clock is populated on the board before using this property.
 
 Optional subnodes:
 Subnodes of the Cadence Quad SPI controller are spi slave nodes with additional
-- 
2.14.1

[PATCH v4 4/6] mtd: spi-nor: cadence-quadspi: Add support to enable loop-back clock circuit

[Vignesh R]

Cadence QSPI IP has a adapted loop-back circuit which can be enabled by
setting BYPASS field to 0 in READCAPTURE register. It enables use of
QSPI return clock to latch the data rather than the internal QSPI
reference clock. For high speed operations, adapted loop-back circuit
using QSPI return clock helps to increase data valid window.

Based on DT parameter cdns,rclk-en enable adapted loop-back circuit
for boards which do have QSPI return clock provided.
This patch also modifies cqspi_readdata_capture() function's bypass
parameter to bool to match how its used in the function.

Signed-off-by: Vignesh R <vigneshr@ti.com>
---
 drivers/mtd/spi-nor/cadence-quadspi.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
index 5cd5d6f7303f..d9629e8f4798 100644
--- a/drivers/mtd/spi-nor/cadence-quadspi.c
+++ b/drivers/mtd/spi-nor/cadence-quadspi.c
@@ -78,6 +78,7 @@ struct cqspi_st {
 	bool			is_decoded_cs;
 	u32			fifo_depth;
 	u32			fifo_width;
+	bool			rclk_en;
 	u32			trigger_address;
 	u32			wr_delay;
 	struct cqspi_flash_pdata f_pdata[CQSPI_MAX_CHIPSELECT];
@@ -788,7 +789,7 @@ static void cqspi_config_baudrate_div(struct cqspi_st *cqspi)
 }
 
 static void cqspi_readdata_capture(struct cqspi_st *cqspi,
-				   const unsigned int bypass,
+				   const bool bypass,
 				   const unsigned int delay)
 {
 	void __iomem *reg_base = cqspi->iobase;
@@ -852,7 +853,8 @@ static void cqspi_configure(struct spi_nor *nor)
 		cqspi->sclk = sclk;
 		cqspi_config_baudrate_div(cqspi);
 		cqspi_delay(nor);
-		cqspi_readdata_capture(cqspi, 1, f_pdata->read_delay);
+		cqspi_readdata_capture(cqspi, !cqspi->rclk_en,
+				       f_pdata->read_delay);
 	}
 
 	if (switch_cs || switch_ck)
@@ -1049,6 +1051,8 @@ static int cqspi_of_get_pdata(struct platform_device *pdev)
 		return -ENXIO;
 	}
 
+	cqspi->rclk_en = of_property_read_bool(np, "cdns,rclk-en");
+
 	return 0;
 }
 
-- 
2.14.1

[PATCH v4 5/6] mtd: spi-nor: cadence-quadspi: Fix error path in probe

[Vignesh R]

Fix the reversed goto labels, so that we disable cqspi controller only
if its enabled previously. This is a minor cleanup.

Signed-off-by: Vignesh R <vigneshr@ti.com>
---
 drivers/mtd/spi-nor/cadence-quadspi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
index d9629e8f4798..60b557e00cfb 100644
--- a/drivers/mtd/spi-nor/cadence-quadspi.c
+++ b/drivers/mtd/spi-nor/cadence-quadspi.c
@@ -1255,9 +1255,9 @@ static int cqspi_probe(struct platform_device *pdev)
 	}
 
 	return ret;
-probe_irq_failed:
-	cqspi_controller_enable(cqspi, 0);
 probe_setup_failed:
+	cqspi_controller_enable(cqspi, 0);
+probe_irq_failed:
 	clk_disable_unprepare(cqspi->clk);
 	return ret;
 }
-- 
2.14.1

[PATCH v4 6/6] mtd: spi-nor: cadence-quadspi: Add runtime PM support

[Vignesh R]

Add pm_runtime* calls to cadence-quadspi driver. This is required to
switch on QSPI power domain on TI 66AK2G SoC during probe.

Signed-off-by: Vignesh R <vigneshr@ti.com>
---
v4: Disable pm in error path.

 drivers/mtd/spi-nor/cadence-quadspi.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
index 60b557e00cfb..75a2bc447a99 100644
--- a/drivers/mtd/spi-nor/cadence-quadspi.c
+++ b/drivers/mtd/spi-nor/cadence-quadspi.c
@@ -31,6 +31,7 @@
 #include <linux/of_device.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/sched.h>
 #include <linux/spi/spi.h>
 #include <linux/timer.h>
@@ -1224,10 +1225,17 @@ static int cqspi_probe(struct platform_device *pdev)
 		return -ENXIO;
 	}
 
+	pm_runtime_enable(dev);
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(dev);
+		return ret;
+	}
+
 	ret = clk_prepare_enable(cqspi->clk);
 	if (ret) {
 		dev_err(dev, "Cannot enable QSPI clock.\n");
-		return ret;
+		goto probe_clk_failed;
 	}
 
 	cqspi->master_ref_clk_hz = clk_get_rate(cqspi->clk);
@@ -1259,6 +1267,9 @@ static int cqspi_probe(struct platform_device *pdev)
 	cqspi_controller_enable(cqspi, 0);
 probe_irq_failed:
 	clk_disable_unprepare(cqspi->clk);
+probe_clk_failed:
+	pm_runtime_put_sync(dev);
+	pm_runtime_disable(dev);
 	return ret;
 }
 
@@ -1275,6 +1286,9 @@ static int cqspi_remove(struct platform_device *pdev)
 
 	clk_disable_unprepare(cqspi->clk);
 
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
 	return 0;
 }
 
-- 
2.14.1

Re: [PATCH v4 0/6] K2G: Add QSPI support

[Vignesh R]

On Tuesday 03 October 2017 10:49 AM, Vignesh R wrote:
> 
> 
> This series adds support for Cadence QSPI IP present in TI's 66AK2G SoC.
> The patches enhance the existing cadence-quadspi driver to support
> loopback clock circuit, pm_runtime support and tweaks for 66AK2G SoC.

Gentle ping on the series...

> 
> Change log:
> 
> v4:
> * New patch to fix error handling sequence in probe.
> 
> v3:
> * Fix build warnings reported by kbuild test bot.
> 
> Resend:
> * Rebase to latest linux-next.
> * Collect Acked-bys
> 
> v2:
> * Drop DT patches. Will be sent as separate series as requested by
>  maintainer.
> * Split binding docs into separate patches.
> * Address comments by Rob Herring.
> 
> Vignesh R (6):
>   mtd: spi-nor: cadence-quadspi: Add TI 66AK2G SoC specific compatible
>   mtd: spi-nor: cadence-quadspi: add a delay in write sequence
>   mtd: spi-nor: cadence-quadspi: Add new binding to enable loop-back
>     circuit
>   mtd: spi-nor: cadence-quadspi: Add support to enable loop-back clock
>     circuit
>   mtd: spi-nor: cadence-quadspi: Fix error path in probe
>   mtd: spi-nor: cadence-quadspi: Add runtime PM support
> 
>  .../devicetree/bindings/mtd/cadence-quadspi.txt    |  7 ++-
>  drivers/mtd/spi-nor/cadence-quadspi.c              | 55 +++++++++++++++++++---
>  2 files changed, 55 insertions(+), 7 deletions(-)
> 

-- 
Regards
Vignesh

Re: [PATCH v4 0/6] K2G: Add QSPI support

[Marek Vasut]

On 10/16/2017 08:15 AM, Vignesh R wrote:
> 
> 
> On Tuesday 03 October 2017 10:49 AM, Vignesh R wrote:
>>
>>
>> This series adds support for Cadence QSPI IP present in TI's 66AK2G SoC.
>> The patches enhance the existing cadence-quadspi driver to support
>> loopback clock circuit, pm_runtime support and tweaks for 66AK2G SoC.
> 
> Gentle ping on the series...

It's IMO OK, Cyrille, can you pick it ?

>>
>> Change log:
>>
>> v4:
>> * New patch to fix error handling sequence in probe.
>>
>> v3:
>> * Fix build warnings reported by kbuild test bot.
>>
>> Resend:
>> * Rebase to latest linux-next.
>> * Collect Acked-bys
>>
>> v2:
>> * Drop DT patches. Will be sent as separate series as requested by
>>  maintainer.
>> * Split binding docs into separate patches.
>> * Address comments by Rob Herring.
>>
>> Vignesh R (6):
>>   mtd: spi-nor: cadence-quadspi: Add TI 66AK2G SoC specific compatible
>>   mtd: spi-nor: cadence-quadspi: add a delay in write sequence
>>   mtd: spi-nor: cadence-quadspi: Add new binding to enable loop-back
>>     circuit
>>   mtd: spi-nor: cadence-quadspi: Add support to enable loop-back clock
>>     circuit
>>   mtd: spi-nor: cadence-quadspi: Fix error path in probe
>>   mtd: spi-nor: cadence-quadspi: Add runtime PM support
>>
>>  .../devicetree/bindings/mtd/cadence-quadspi.txt    |  7 ++-
>>  drivers/mtd/spi-nor/cadence-quadspi.c              | 55 +++++++++++++++++++---
>>  2 files changed, 55 insertions(+), 7 deletions(-)
>>
> 


-- 
Best regards,
Marek Vasut

Re: [PATCH v4 0/6] K2G: Add QSPI support

[Cyrille Pitchen]

Hi all,

Le 16/10/2017 à 11:28, Marek Vasut a écrit :
> On 10/16/2017 08:15 AM, Vignesh R wrote:
>>
>>
>> On Tuesday 03 October 2017 10:49 AM, Vignesh R wrote:
>>>
>>>
>>> This series adds support for Cadence QSPI IP present in TI's 66AK2G SoC.
>>> The patches enhance the existing cadence-quadspi driver to support
>>> loopback clock circuit, pm_runtime support and tweaks for 66AK2G SoC.
>>
>> Gentle ping on the series...
> 
> It's IMO OK, Cyrille, can you pick it ?
>

The series looks good to me too.

Marek, could you please add you "Acked-by" or "Reviewed-by" tag for the
record in patchwork ? It will be automatically added when I use
"pwclient git-am -s" to merge the patches into the spi-nor/next branch.

Best regards,

Cyrille


>>>
>>> Change log:
>>>
>>> v4:
>>> * New patch to fix error handling sequence in probe.
>>>
>>> v3:
>>> * Fix build warnings reported by kbuild test bot.
>>>
>>> Resend:
>>> * Rebase to latest linux-next.
>>> * Collect Acked-bys
>>>
>>> v2:
>>> * Drop DT patches. Will be sent as separate series as requested by
>>>  maintainer.
>>> * Split binding docs into separate patches.
>>> * Address comments by Rob Herring.
>>>
>>> Vignesh R (6):
>>>   mtd: spi-nor: cadence-quadspi: Add TI 66AK2G SoC specific compatible
>>>   mtd: spi-nor: cadence-quadspi: add a delay in write sequence
>>>   mtd: spi-nor: cadence-quadspi: Add new binding to enable loop-back
>>>     circuit
>>>   mtd: spi-nor: cadence-quadspi: Add support to enable loop-back clock
>>>     circuit
>>>   mtd: spi-nor: cadence-quadspi: Fix error path in probe
>>>   mtd: spi-nor: cadence-quadspi: Add runtime PM support
>>>
>>>  .../devicetree/bindings/mtd/cadence-quadspi.txt    |  7 ++-
>>>  drivers/mtd/spi-nor/cadence-quadspi.c              | 55 +++++++++++++++++++---
>>>  2 files changed, 55 insertions(+), 7 deletions(-)
>>>
>>
> 
> 

Re: [PATCH v4 0/6] K2G: Add QSPI support

[Marek Vasut]

On 10/17/2017 12:29 AM, Cyrille Pitchen wrote:
> Hi all,
> 
> Le 16/10/2017 à 11:28, Marek Vasut a écrit :
>> On 10/16/2017 08:15 AM, Vignesh R wrote:
>>>
>>>
>>> On Tuesday 03 October 2017 10:49 AM, Vignesh R wrote:
>>>>
>>>>
>>>> This series adds support for Cadence QSPI IP present in TI's 66AK2G SoC.
>>>> The patches enhance the existing cadence-quadspi driver to support
>>>> loopback clock circuit, pm_runtime support and tweaks for 66AK2G SoC.
>>>
>>> Gentle ping on the series...
>>
>> It's IMO OK, Cyrille, can you pick it ?
>>
> 
> The series looks good to me too.
> 
> Marek, could you please add you "Acked-by" or "Reviewed-by" tag for the
> record in patchwork ? It will be automatically added when I use
> "pwclient git-am -s" to merge the patches into the spi-nor/next branch.

Acked-by: Marek Vasut <marek.vasut@gmail.com>

-- 
Best regards,
Marek Vasut

Re: [PATCH v4 0/6] K2G: Add QSPI support

[Cyrille Pitchen]

Le 17/10/2017 à 00:34, Marek Vasut a écrit :
> On 10/17/2017 12:29 AM, Cyrille Pitchen wrote:
>> Hi all,
>>
>> Le 16/10/2017 à 11:28, Marek Vasut a écrit :
>>> On 10/16/2017 08:15 AM, Vignesh R wrote:
>>>>
>>>>
>>>> On Tuesday 03 October 2017 10:49 AM, Vignesh R wrote:
>>>>>
>>>>>
>>>>> This series adds support for Cadence QSPI IP present in TI's 66AK2G SoC.
>>>>> The patches enhance the existing cadence-quadspi driver to support
>>>>> loopback clock circuit, pm_runtime support and tweaks for 66AK2G SoC.
>>>>
>>>> Gentle ping on the series...
>>>
>>> It's IMO OK, Cyrille, can you pick it ?
>>>
>>
>> The series looks good to me too.
>>
>> Marek, could you please add you "Acked-by" or "Reviewed-by" tag for the
>> record in patchwork ? It will be automatically added when I use
>> "pwclient git-am -s" to merge the patches into the spi-nor/next branch.
> 
> Acked-by: Marek Vasut <marek.vasut@gmail.com>
> 

added Marek's "Acked-by" tags on the whole series and applied it into
the spi-nor/next branch of l2-mtd

Thanks!