Re: [PATCH v8 3/6] spi: cadence-quadspi: Add multi-chipselect support for Intel LGM SoC

From: "Ramuthevar, Vadivel MuruganX"  <vadivel.muruganx.ramuthevar@linux.intel.com>
To: Vignesh Raghavendra <vigneshr@ti.com>,
	broonie@kernel.org, linux-kernel@vger.kernel.org,
	linux-spi@vger.kernel.org
Cc: linux-mtd@lists.infradead.org, p.yadav@ti.com,
	cheol.yong.kim@intel.com, qi-ming.wu@intel.com
Subject: Re: [PATCH v8 3/6] spi: cadence-quadspi: Add multi-chipselect support for Intel LGM SoC
Date: Fri, 20 Nov 2020 08:29:51 +0800	[thread overview]
Message-ID: <4d0f82a8-f87d-ba75-336f-564d89083732@linux.intel.com> (raw)
In-Reply-To: <9fc328cc-1f4d-1896-6dde-a107d76e14cb@ti.com>

Hi Vignesh,

Thank you very much for the review comments...

On 19/11/2020 8:57 pm, Vignesh Raghavendra wrote:
> 
> 
> On 11/19/20 11:25 AM, Ramuthevar,Vadivel MuruganX wrote:
>> From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>
>>
>> Add multiple chipselect support for Intel LGM SoCs,
>> currently QSPI-NOR and QSPI-NAND supported.
>>
>> Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>
>> ---
>>   drivers/spi/spi-cadence-quadspi.c | 15 +++++++++++++++
>>   1 file changed, 15 insertions(+)
>>
>> diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
>> index d12b765e87be..337778f75d5d 100644
>> --- a/drivers/spi/spi-cadence-quadspi.c
>> +++ b/drivers/spi/spi-cadence-quadspi.c
>> @@ -38,6 +38,7 @@
>>   
>>   /* Capabilities */
>>   #define CQSPI_SUPPORTS_OCTAL		BIT(0)
>> +#define CQSPI_SUPPORTS_MULTI_CHIPSELECT BIT(1)
>>   
>>   struct cqspi_st;
>>   
>> @@ -75,6 +76,7 @@ struct cqspi_st {
>>   	bool			is_decoded_cs;
>>   	u32			fifo_depth;
>>   	u32			fifo_width;
>> +	u32			num_chipselect;
>>   	bool			rclk_en;
>>   	u32			trigger_address;
>>   	u32			wr_delay;
>> @@ -1049,6 +1051,7 @@ static int cqspi_of_get_flash_pdata(struct platform_device *pdev,
>>   
>>   static int cqspi_of_get_pdata(struct cqspi_st *cqspi)
>>   {
>> +	const struct cqspi_driver_platdata *ddata;
> 
> Unused variable?
currently used for this check
if (ddata->hwcaps_mask & CQSPI_SUPPORTS_MULTI_CHIPSELECT) {

next patch will drop it, because the above check to be removed.
> 
>>   	struct device *dev = &cqspi->pdev->dev;
>>   	struct device_node *np = dev->of_node;
>>   
>> @@ -1070,6 +1073,14 @@ static int cqspi_of_get_pdata(struct cqspi_st *cqspi)
>>   		return -ENXIO;
>>   	}
>>   
>> +	ddata  = of_device_get_match_data(dev);
>> +	if (ddata->hwcaps_mask & CQSPI_SUPPORTS_MULTI_CHIPSELECT) {
> 
> I don't see a need for this flag... Controller by default supports
> multiple CS.
Ok.
> 
>> +		if (of_property_read_u32(np, "num-cs", &cqspi->num_chipselect)) {
>> +			dev_err(dev, "couldn't determine number of cs\n");
>> +			return -ENXIO;
>> +		}
>> +	}
>> +
> 
> 
> Entire hunk can be replaced with:
> 
>          if (of_property_read_u32(np, "num-cs", &cqspi->num_chipselect))
> 		cqspi->num_chipselect = CQSPI_MAX_CHIPSELECT;
Noted, thanks!
> 
> 
>>   	cqspi->rclk_en = of_property_read_bool(np, "cdns,rclk-en");
>>   
>>   	return 0;
>> @@ -1302,6 +1313,9 @@ static int cqspi_probe(struct platform_device *pdev)
>>   	cqspi->current_cs = -1;
>>   	cqspi->sclk = 0;
>>   
>> +	if (ddata->hwcaps_mask & CQSPI_SUPPORTS_MULTI_CHIPSELECT)
>> +		master->num_chipselect = cqspi->num_chipselect;
>> +
> 
> And then this becomes:
> 	master->num_chipselect = cqspi->num_chipselect;
Ok, Noted.
> 
>>   	ret = cqspi_setup_flash(cqspi);
>>   	if (ret) {
>>   		dev_err(dev, "failed to setup flash parameters %d\n", ret);
>> @@ -1391,6 +1405,7 @@ static const struct cqspi_driver_platdata am654_ospi = {
>>   };
>>   
>>   static const struct cqspi_driver_platdata intel_lgm_qspi = {
>> +	.hwcaps_mask = CQSPI_SUPPORTS_MULTI_CHIPSELECT,
>>   	.quirks = CQSPI_DISABLE_DAC_MODE,
>>   };
>>   
>>