Subject: [PATCH 3/4] spi: s3c64xx: add nexynos5433 compatible for ioclk handling

From: [email-masked] (Krzysztof Kozlowski)
Date: Fri, 08 Jul 2016 15:21:18 +0200

On 07/08/2016 02:18 PM, Andi Shyti wrote:
> The new compatible is related to the Samsunx exynos5433 SoC. The

s/Samsunx/Samsung
Capitalize first letter: Exynos5433

> difference between the previous is that in the exynos5433 the SPI
> controller is driven by three clocks instead of only one.
> 
> The new clock (ioclk) is controlling the input/output clock
> whenever the controller is slave or master.
> 
> The presence of the clock line is detected from the compatibility
> structure (exynos5433_spi_port_config) as a boolean value.
> 
> The probe function checks whether the ioclk is present and if so,
> it acquires.
> 
> The runtime suspend and resume functions will handle the clock
> enabling and disabling as well.
> 
> Signed-off-by: Andi Shyti <[email-masked]>
> ---
>  drivers/spi/spi-s3c64xx.c | 57 ++++++++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 52 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
> index 2ab42b2..1874bc5 100644
> --- a/drivers/spi/spi-s3c64xx.c
> +++ b/drivers/spi/spi-s3c64xx.c
> @@ -156,12 +156,14 @@ struct s3c64xx_spi_port_config {
>  	int	quirks;
>  	bool	high_speed;
>  	bool	clk_from_cmu;
> +	bool	clk_ioclk;
>  };
>  
>  /**
>   * struct s3c64xx_spi_driver_data - Runtime info holder for SPI driver.
>   * @clk: Pointer to the spi clock.
>   * @src_clk: Pointer to the clock used to generate SPI signals.
> + * @ioclk: Pointer to the i/o clock between master and slave
>   * @master: Pointer to the SPI Protocol master.
>   * @cntrlr_info: Platform specific data for the controller this driver manages.
>   * @tgl_spi: Pointer to the last CS left untoggled by the cs_change hint.
> @@ -181,6 +183,7 @@ struct s3c64xx_spi_driver_data {
>  	void __iomem                    *regs;
>  	struct clk                      *clk;
>  	struct clk                      *src_clk;
> +	struct clk                      *ioclk;
>  	struct platform_device          *pdev;
>  	struct spi_master               *master;
>  	struct s3c64xx_spi_info  *cntrlr_info;
> @@ -1147,6 +1150,21 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
>  		goto err_disable_clk;
>  	}
>  
> +	if (sdd->port_conf->clk_ioclk) {
> +		sdd->ioclk = devm_clk_get(&pdev->dev, "spi_ioclk");
> +		if (IS_ERR(sdd->ioclk)) {
> +			dev_err(&pdev->dev, "Unable to acquire 'ioclk'\n");
> +			ret = PTR_ERR(sdd->ioclk);
> +			goto err_disable_src_clk;
> +		}
> +
> +		if (clk_prepare_enable(sdd->ioclk)) {
> +			dev_err(&pdev->dev, "Couldn't enable clock 'ioclk'\n");
> +			ret = -EBUSY;

Why not returning real error code from clk_prepare_enable()?

> +			goto err_disable_src_clk;
> +		}
> +	}
> +
>  	pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
>  	pm_runtime_use_autosuspend(&pdev->dev);
>  	pm_runtime_set_active(&pdev->dev);
> @@ -1193,6 +1211,8 @@ err_power_off:
>  	pm_runtime_disable(&pdev->dev);
>  	pm_runtime_set_suspended(&pdev->dev);
>  
> +	clk_disable_unprepare(sdd->ioclk);
> +err_disable_src_clk:
>  	clk_disable_unprepare(sdd->src_clk);
>  err_disable_clk:
>  	clk_disable_unprepare(sdd->clk);
> @@ -1211,6 +1231,8 @@ static int s3c64xx_spi_remove(struct platform_device *pdev)
>  
>  	writel(0, sdd->regs + S3C64XX_SPI_INT_EN);
>  
> +	clk_disable_unprepare(sdd->ioclk);
> +
>  	clk_disable_unprepare(sdd->src_clk);
>  
>  	clk_disable_unprepare(sdd->clk);
> @@ -1269,6 +1291,7 @@ static int s3c64xx_spi_runtime_suspend(struct device *dev)
>  
>  	clk_disable_unprepare(sdd->clk);
>  	clk_disable_unprepare(sdd->src_clk);
> +	clk_disable_unprepare(sdd->ioclk);
>  
>  	return 0;
>  }
> @@ -1279,17 +1302,28 @@ static int s3c64xx_spi_runtime_resume(struct device *dev)
>  	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
>  	int ret;
>  
> +	if (sdd->port_conf->clk_ioclk) {
> +		ret = clk_prepare_enable(sdd->ioclk);
> +		if (ret != 0)
> +			return ret;
> +	}
> +
>  	ret = clk_prepare_enable(sdd->src_clk);
>  	if (ret != 0)
> -		return ret;
> +		goto err_disable_ioclk;
>  
>  	ret = clk_prepare_enable(sdd->clk);
> -	if (ret != 0) {
> -		clk_disable_unprepare(sdd->src_clk);
> -		return ret;
> -	}
> +	if (ret != 0)
> +		goto err_disable_src_clk;
>  
>  	return 0;
> +
> +err_disable_src_clk:
> +	clk_disable_unprepare(sdd->src_clk);
> +err_disable_ioclk:
> +	clk_disable_unprepare(sdd->ioclk);
> +
> +	return ret;
>  }
>  #endif /* CONFIG_PM */
>  
> @@ -1345,6 +1379,16 @@ static struct s3c64xx_spi_port_config exynos7_spi_port_config = {
>  	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
>  };
>  
> +static struct s3c64xx_spi_port_config exynos5433_spi_port_config = {
> +	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F, 0x7F, 0x7F, 0x1ff},

Don't mix lower and upper cases of hex. I know that existing ones mixed
it... but let us fix at least new code.

Best regards,
Krzysztof