Re: [PATCH 1/3] spi: s3c64xx: simplify probe function by using local variable for &pdev->dev

[Heiner Kallweit <hkallweit1@xxxxxxxxx>]

Am 19.08.2015 um 01:56 schrieb Krzysztof Kozlowski:
> On 19.08.2015 06:05, Heiner Kallweit wrote:
>> Simplify the probe function by replacing all occurrences of &pdev->dev
>> with a local variable.
>>
>> Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
>> ---
>>  drivers/spi/spi-s3c64xx.c | 58 +++++++++++++++++++++++------------------------
>>  1 file changed, 29 insertions(+), 29 deletions(-)
> 
> I don't see simplification here (the same number of insertions as
> deletions, code is exactly the same). &pdev->dev is a common pattern in
> most of platform drivers.
Right, &pdev->dev is a common pattern. I consider the new version better as we
really have a lot of occurrences of &pdev->dev. It reduces complexity in several lines
and might save a few CPU cycles in case the compiler can't hold &pdev->dev in a register
all the time.
Of course your mileage might vary. If you think it's good as it is I'm also fine with it.

Rgds, Heiner
> 
> Best regards,
> Krzysztof
> 
> 
>>
>> diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
>> index cd1cfac..c4d3b06 100644
>> --- a/drivers/spi/spi-s3c64xx.c
>> +++ b/drivers/spi/spi-s3c64xx.c
>> @@ -1024,39 +1024,39 @@ static inline struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
>>  
>>  static int s3c64xx_spi_probe(struct platform_device *pdev)
>>  {
>> +	struct device *dev = &pdev->dev;
>>  	struct resource	*mem_res;
>>  	struct resource	*res;
>>  	struct s3c64xx_spi_driver_data *sdd;
>> -	struct s3c64xx_spi_info *sci = dev_get_platdata(&pdev->dev);
>> +	struct s3c64xx_spi_info *sci = dev_get_platdata(dev);
>>  	struct spi_master *master;
>>  	int ret, irq;
>>  	char clk_name[16];
>>  
>> -	if (!sci && pdev->dev.of_node) {
>> -		sci = s3c64xx_spi_parse_dt(&pdev->dev);
>> +	if (!sci && dev->of_node) {
>> +		sci = s3c64xx_spi_parse_dt(dev);
>>  		if (IS_ERR(sci))
>>  			return PTR_ERR(sci);
>>  	}
>>  
>>  	if (!sci) {
>> -		dev_err(&pdev->dev, "platform_data missing!\n");
>> +		dev_err(dev, "platform_data missing!\n");
>>  		return -ENODEV;
>>  	}
>>  
>>  	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>  	if (mem_res == NULL) {
>> -		dev_err(&pdev->dev, "Unable to get SPI MEM resource\n");
>> +		dev_err(dev, "Unable to get SPI MEM resource\n");
>>  		return -ENXIO;
>>  	}
>>  
>>  	irq = platform_get_irq(pdev, 0);
>>  	if (irq < 0) {
>> -		dev_warn(&pdev->dev, "Failed to get IRQ: %d\n", irq);
>> +		dev_warn(dev, "Failed to get IRQ: %d\n", irq);
>>  		return irq;
>>  	}
>>  
>> -	master = spi_alloc_master(&pdev->dev,
>> -				sizeof(struct s3c64xx_spi_driver_data));
>> +	master = spi_alloc_master(dev, sizeof(struct s3c64xx_spi_driver_data));
>>  	if (master == NULL) {
>>  		dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
>>  		return -ENOMEM;
>> @@ -1071,9 +1071,9 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
>>  	sdd->pdev = pdev;
>>  	sdd->sfr_start = mem_res->start;
>>  	if (pdev->dev.of_node) {
>> -		ret = of_alias_get_id(pdev->dev.of_node, "spi");
>> +		ret = of_alias_get_id(dev->of_node, "spi");
>>  		if (ret < 0) {
>> -			dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
>> +			dev_err(dev, "failed to get alias id, errno %d\n",
>>  				ret);
>>  			goto err0;
>>  		}
>> @@ -1087,14 +1087,14 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
>>  	if (!sdd->pdev->dev.of_node) {
>>  		res = platform_get_resource(pdev, IORESOURCE_DMA,  0);
>>  		if (!res) {
>> -			dev_warn(&pdev->dev, "Unable to get SPI tx dma resource. Switching to poll mode\n");
>> +			dev_warn(dev, "Unable to get SPI tx dma resource. Switching to poll mode\n");
>>  			sdd->port_conf->quirks = S3C64XX_SPI_QUIRK_POLL;
>>  		} else
>>  			sdd->tx_dma.dmach = res->start;
>>  
>>  		res = platform_get_resource(pdev, IORESOURCE_DMA,  1);
>>  		if (!res) {
>> -			dev_warn(&pdev->dev, "Unable to get SPI rx dma resource. Switching to poll mode\n");
>> +			dev_warn(dev, "Unable to get SPI rx dma resource. Switching to poll mode\n");
>>  			sdd->port_conf->quirks = S3C64XX_SPI_QUIRK_POLL;
>>  		} else
>>  			sdd->rx_dma.dmach = res->start;
>> @@ -1103,7 +1103,7 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
>>  	sdd->tx_dma.direction = DMA_MEM_TO_DEV;
>>  	sdd->rx_dma.direction = DMA_DEV_TO_MEM;
>>  
>> -	master->dev.of_node = pdev->dev.of_node;
>> +	master->dev.of_node = dev->of_node;
>>  	master->bus_num = sdd->port_id;
>>  	master->setup = s3c64xx_spi_setup;
>>  	master->cleanup = s3c64xx_spi_cleanup;
>> @@ -1121,43 +1121,43 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
>>  	if (!is_polling(sdd))
>>  		master->can_dma = s3c64xx_spi_can_dma;
>>  
>> -	sdd->regs = devm_ioremap_resource(&pdev->dev, mem_res);
>> +	sdd->regs = devm_ioremap_resource(dev, mem_res);
>>  	if (IS_ERR(sdd->regs)) {
>>  		ret = PTR_ERR(sdd->regs);
>>  		goto err0;
>>  	}
>>  
>>  	if (sci->cfg_gpio && sci->cfg_gpio()) {
>> -		dev_err(&pdev->dev, "Unable to config gpio\n");
>> +		dev_err(dev, "Unable to config gpio\n");
>>  		ret = -EBUSY;
>>  		goto err0;
>>  	}
>>  
>>  	/* Setup clocks */
>> -	sdd->clk = devm_clk_get(&pdev->dev, "spi");
>> +	sdd->clk = devm_clk_get(dev, "spi");
>>  	if (IS_ERR(sdd->clk)) {
>> -		dev_err(&pdev->dev, "Unable to acquire clock 'spi'\n");
>> +		dev_err(dev, "Unable to acquire clock 'spi'\n");
>>  		ret = PTR_ERR(sdd->clk);
>>  		goto err0;
>>  	}
>>  
>>  	if (clk_prepare_enable(sdd->clk)) {
>> -		dev_err(&pdev->dev, "Couldn't enable clock 'spi'\n");
>> +		dev_err(dev, "Couldn't enable clock 'spi'\n");
>>  		ret = -EBUSY;
>>  		goto err0;
>>  	}
>>  
>>  	sprintf(clk_name, "spi_busclk%d", sci->src_clk_nr);
>> -	sdd->src_clk = devm_clk_get(&pdev->dev, clk_name);
>> +	sdd->src_clk = devm_clk_get(dev, clk_name);
>>  	if (IS_ERR(sdd->src_clk)) {
>> -		dev_err(&pdev->dev,
>> +		dev_err(dev,
>>  			"Unable to acquire clock '%s'\n", clk_name);
>>  		ret = PTR_ERR(sdd->src_clk);
>>  		goto err2;
>>  	}
>>  
>>  	if (clk_prepare_enable(sdd->src_clk)) {
>> -		dev_err(&pdev->dev, "Couldn't enable clock '%s'\n", clk_name);
>> +		dev_err(dev, "Couldn't enable clock '%s'\n", clk_name);
>>  		ret = -EBUSY;
>>  		goto err2;
>>  	}
>> @@ -1168,10 +1168,10 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
>>  	spin_lock_init(&sdd->lock);
>>  	init_completion(&sdd->xfer_completion);
>>  
>> -	ret = devm_request_irq(&pdev->dev, irq, s3c64xx_spi_irq, 0,
>> +	ret = devm_request_irq(dev, irq, s3c64xx_spi_irq, 0,
>>  				"spi-s3c64xx", sdd);
>>  	if (ret != 0) {
>> -		dev_err(&pdev->dev, "Failed to request IRQ %d: %d\n",
>> +		dev_err(dev, "Failed to request IRQ %d: %d\n",
>>  			irq, ret);
>>  		goto err3;
>>  	}
>> @@ -1180,18 +1180,18 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
>>  	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
>>  	       sdd->regs + S3C64XX_SPI_INT_EN);
>>  
>> -	pm_runtime_set_active(&pdev->dev);
>> -	pm_runtime_enable(&pdev->dev);
>> +	pm_runtime_set_active(dev);
>> +	pm_runtime_enable(dev);
>>  
>> -	ret = devm_spi_register_master(&pdev->dev, master);
>> +	ret = devm_spi_register_master(dev, master);
>>  	if (ret != 0) {
>> -		dev_err(&pdev->dev, "cannot register SPI master: %d\n", ret);
>> +		dev_err(dev, "cannot register SPI master: %d\n", ret);
>>  		goto err3;
>>  	}
>>  
>> -	dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d with %d Slaves attached\n",
>> +	dev_dbg(dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d with %d Slaves attached\n",
>>  					sdd->port_id, master->num_chipselect);
>> -	dev_dbg(&pdev->dev, "\tIOmem=[%pR]\tFIFO %dbytes\tDMA=[Rx-%d, Tx-%d]\n",
>> +	dev_dbg(dev, "\tIOmem=[%pR]\tFIFO %dbytes\tDMA=[Rx-%d, Tx-%d]\n",
>>  					mem_res, (FIFO_LVL_MASK(sdd) >> 1) + 1,
>>  					sdd->rx_dma.dmach, sdd->tx_dma.dmach);
>>  
>>
> 
> 

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