Re: [PATCH 2/3] spi: sun6i: Support Allwinner H3 SPI controller

[Maxime Ripard]

Hi,

On Wed, Oct 19, 2016 at 11:02:33PM +0900, Milo Kim wrote:
> H3 has two SPI controllers. The size of the buffer is 64 * 8.
> (8 bit transfer by 64 entry FIFO)
> A31 has four controllers. The size of the buffer is 128 * 8.
> (8 bit transfer by 128 entry FIFO)
> 
> Register maps are sharable, so sun6i SPI driver is reusable with
> device configuration.
> 
> Use the variable, 'fifo_depth' instead of fixed value to support both SPI
> controllers.
> 
> Cc: Mark Brown <broonie@xxxxxxxxxx>
> Cc: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
> Cc: Chen-Yu Tsai <wens@xxxxxxxx>
> Signed-off-by: Milo Kim <woogyom.kim@xxxxxxxxx>
> ---
>  drivers/spi/Kconfig     |  4 ++--
>  drivers/spi/spi-sun6i.c | 38 +++++++++++++++++++++++++++-----------
>  2 files changed, 29 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index b799547..06d0845 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -610,11 +610,11 @@ config SPI_SUN4I
>  	  SPI driver for Allwinner sun4i, sun5i and sun7i SoCs
>  
>  config SPI_SUN6I
> -	tristate "Allwinner A31 SPI controller"
> +	tristate "Allwinner A31/H3 SPI controller"
>  	depends on ARCH_SUNXI || COMPILE_TEST
>  	depends on RESET_CONTROLLER
>  	help
> -	  This enables using the SPI controller on the Allwinner A31 SoCs.
> +	  This enables using the SPI controller on the Allwinner A31/H3 SoCs.

Usually, we don't care about maintaining this. This is just going to
be a list that grows all the time, and is wrong most of the time.

>  config SPI_MXS
>  	tristate "Freescale MXS SPI controller"
> diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
> index 9918a57..91235b2 100644
> --- a/drivers/spi/spi-sun6i.c
> +++ b/drivers/spi/spi-sun6i.c
> @@ -17,6 +17,7 @@
>  #include <linux/interrupt.h>
>  #include <linux/io.h>
>  #include <linux/module.h>
> +#include <linux/of_device.h>
>  #include <linux/platform_device.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/reset.h>
> @@ -24,6 +25,7 @@
>  #include <linux/spi/spi.h>
>  
>  #define SUN6I_FIFO_DEPTH		128
> +#define SUN8I_FIFO_DEPTH		64
>  
>  #define SUN6I_GBL_CTL_REG		0x04
>  #define SUN6I_GBL_CTL_BUS_ENABLE		BIT(0)
> @@ -90,6 +92,7 @@ struct sun6i_spi {
>  	const u8		*tx_buf;
>  	u8			*rx_buf;
>  	int			len;
> +	int			fifo_depth;
>  };
>  
>  static inline u32 sun6i_spi_read(struct sun6i_spi *sspi, u32 reg)
> @@ -155,7 +158,9 @@ static void sun6i_spi_set_cs(struct spi_device *spi, bool enable)
>  
>  static size_t sun6i_spi_max_transfer_size(struct spi_device *spi)
>  {
> -	return SUN6I_FIFO_DEPTH - 1;
> +	struct sun6i_spi *sspi = spi_master_get_devdata(spi->master);
> +
> +	return sspi->fifo_depth - 1;
>  }
>  
>  static int sun6i_spi_transfer_one(struct spi_master *master,
> @@ -170,7 +175,7 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
>  	u32 reg;
>  
>  	/* We don't support transfer larger than the FIFO */
> -	if (tfr->len > SUN6I_FIFO_DEPTH)
> +	if (tfr->len > sspi->fifo_depth)
>  		return -EINVAL;
>  
>  	reinit_completion(&sspi->done);
> @@ -265,7 +270,7 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
>  			SUN6I_BURST_CTL_CNT_STC(tx_len));
>  
>  	/* Fill the TX FIFO */
> -	sun6i_spi_fill_fifo(sspi, SUN6I_FIFO_DEPTH);
> +	sun6i_spi_fill_fifo(sspi, sspi->fifo_depth);
>  
>  	/* Enable the interrupts */
>  	sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, SUN6I_INT_CTL_TC);
> @@ -288,7 +293,7 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
>  		goto out;
>  	}
>  
> -	sun6i_spi_drain_fifo(sspi, SUN6I_FIFO_DEPTH);
> +	sun6i_spi_drain_fifo(sspi, sspi->fifo_depth);
>  
>  out:
>  	sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, 0);
> @@ -360,8 +365,16 @@ static int sun6i_spi_runtime_suspend(struct device *dev)
>  	return 0;
>  }
>  
> +static const struct of_device_id sun6i_spi_match[] = {
> +	{ .compatible = "allwinner,sun6i-a31-spi", .data = (int *)SUN6I_FIFO_DEPTH },
> +	{ .compatible = "allwinner,sun8i-h3-spi", .data = (int *)SUN8I_FIFO_DEPTH },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, sun6i_spi_match);
> +
>  static int sun6i_spi_probe(struct platform_device *pdev)
>  {
> +	const struct of_device_id *id;
>  	struct spi_master *master;
>  	struct sun6i_spi *sspi;
>  	struct resource	*res;
> @@ -398,6 +411,15 @@ static int sun6i_spi_probe(struct platform_device *pdev)
>  	}
>  
>  	sspi->master = master;
> +
> +	id = of_match_device(sun6i_spi_match, &pdev->dev);
> +	if (!id) {
> +		dev_err(&pdev->dev, "Cannot get device ID\n");
> +		goto err_free_master;
> +	}
> +
> +	sspi->fifo_depth = (int)id->data;
> +
>  	master->max_speed_hz = 100 * 1000 * 1000;
>  	master->min_speed_hz = 3 * 1000;
>  	master->set_cs = sun6i_spi_set_cs;
> @@ -469,12 +491,6 @@ static int sun6i_spi_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -static const struct of_device_id sun6i_spi_match[] = {
> -	{ .compatible = "allwinner,sun6i-a31-spi", },
> -	{}
> -};
> -MODULE_DEVICE_TABLE(of, sun6i_spi_match);
> -
>  static const struct dev_pm_ops sun6i_spi_pm_ops = {
>  	.runtime_resume		= sun6i_spi_runtime_resume,
>  	.runtime_suspend	= sun6i_spi_runtime_suspend,
> @@ -493,5 +509,5 @@ module_platform_driver(sun6i_spi_driver);
>  
>  MODULE_AUTHOR("Pan Nan <pannan@xxxxxxxxxxxxxxxxx>");
>  MODULE_AUTHOR("Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>");
> -MODULE_DESCRIPTION("Allwinner A31 SPI controller driver");
> +MODULE_DESCRIPTION("Allwinner A31/H3 SPI controller driver");

Ditto.

It looks good otherwise.

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

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