Re: [v4 PATCH 05/12] spi/atmel_spi: update the dt support

[Jean-Christophe PLAGNIOL-VILLARD]

On 15:34 Mon 14 Jan     , Wenyou Yang wrote:
> To meet the different spi IP version of atmel SoC,
> add the more compatible with different config and devtype.
> 
> The "has_dma_support" is used to select the dma engine transfer mode.
> 
> The "has_wdrbt" indicate if there is the "WDRBT" bit in the Mode Register,
> WDRBT (Wait Data Read Before Transfer),if WDRBT is set,
> a transfer can start only if the Receive Data Register is empty,i.e. does not
> contain any unread data, to prevent overrun error in reception
> 
> Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxx>
> ---
>  drivers/spi/spi-atmel.c |  134 ++++++++++++++++++++++++++++++++++++++++-------
>  1 file changed, 115 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
> index 8f6f0a0..43c1f63 100644
> --- a/drivers/spi/spi-atmel.c
> +++ b/drivers/spi/spi-atmel.c
> @@ -71,6 +71,8 @@
>  #define SPI_FDIV_SIZE				1
>  #define SPI_MODFDIS_OFFSET			4
>  #define SPI_MODFDIS_SIZE			1
> +#define SPI_WDRBT_OFFSET			5
> +#define SPI_WDRBT_SIZE				1
>  #define SPI_LLB_OFFSET				7
>  #define SPI_LLB_SIZE				1
>  #define SPI_PCS_OFFSET				16
> @@ -186,6 +188,12 @@
>   * DMA transfers; transfer queue progress is driven by IRQs.  The clock
>   * framework provides the base clock, subdivided for each spi_device.
>   */
> +struct atmel_spi_pdata {
> +	u8	version;
> +	bool	has_dma_support;
> +	bool	has_wdrbt;
> +};
> +
>  struct atmel_spi {
>  	spinlock_t		lock;
>  	unsigned long		flags;
> @@ -204,6 +212,7 @@ struct atmel_spi {
>  	struct spi_transfer	*next_transfer;
>  	unsigned long		next_remaining_bytes;
>  	int			done_status;
> +	struct atmel_spi_pdata	*pdata;
>  
>  	void			*buffer;
>  	dma_addr_t		buffer_dma;
> @@ -218,6 +227,69 @@ struct atmel_spi_device {
>  #define BUFFER_SIZE		PAGE_SIZE
>  #define INVALID_DMA_ADDRESS	0xffffffff
>  
> +static struct atmel_spi_pdata at91rm9200_config = {
> +	.version = 1,
> +	.has_dma_support = false,
> +	.has_wdrbt = false,
> +};
> +
> +static struct atmel_spi_pdata at91sam9260_config = {
> +	.version = 2,
> +	.has_dma_support = false,
> +	.has_wdrbt = false,
> +};
> +
> +static struct atmel_spi_pdata at91sam9g45_config = {
> +	.version = 2,
> +	.has_dma_support = false,
> +	.has_wdrbt = true,
> +};
> +
> +static struct atmel_spi_pdata at91sam9x5_config = {
> +	.version = 2,
> +	.has_dma_support = true,
> +	.has_wdrbt = true,
> +};
> +
> +static const struct platform_device_id atmel_spi_devtypes[] = {
> +	{
> +		.name = "spi-at91rm9200",
> +		.driver_data = (unsigned long) &at91rm9200_config,
> +	}, {
> +		.name = "spi-at91sam9260",
> +		.driver_data = (unsigned long) &at91sam9260_config,
> +	}, {
> +		.name = "spi-at91sam9g45",
> +		.driver_data = (unsigned long) &at91sam9g45_config,
> +	}, {
> +		.name = "spi-at91sam9x5",
> +		.driver_data = (unsigned long) &at91sam9x5_config,
> +	}, {
> +		/* sentinel */
> +	}
> +};
> +
> +#if defined(CONFIG_OF)
> +static const struct of_device_id atmel_spi_dt_ids[] = {
> +	{
> +		.compatible = "atmel,at91rm9200-spi",
> +		.data = &at91rm9200_config,
> +	} , {
> +		.compatible = "atmel,at91sam9260-spi",
> +		.data = &at91sam9260_config,
> +	} , {
> +		.compatible = "atmel,at91sam9g45-spi",
> +		.data = &at91sam9g45_config,
> +	} , {
> +		.compatible = "atmel,at91sam9x5-spi",
> +		.data = &at91sam9x5_config,
> +	}, {
> +		/* sentinel */
use the IP revision register to detect it

IIRC 0xfc

Best Regards,
J.
> +	}
> +};
> +MODULE_DEVICE_TABLE(of, atmel_spi_dt_ids);
> +#endif
> +
>  /*
>   * Version 2 of the SPI controller has
>   *  - CR.LASTXFER
> @@ -230,11 +302,12 @@ struct atmel_spi_device {
>   * register, but I haven't checked that it exists on all chips, and
>   * this is cheaper anyway.
>   */
> -static bool atmel_spi_is_v2(void)
> +static bool atmel_spi_is_v2(struct atmel_spi *as)
>  {
> -	return !cpu_is_at91rm9200();
> +	return as->pdata->version == 2;
>  }
>  
> +
>  /*
>   * Earlier SPI controllers (e.g. on at91rm9200) have a design bug whereby
>   * they assume that spi slave device state will not change on deselect, so
> @@ -266,15 +339,21 @@ static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
>  	unsigned active = spi->mode & SPI_CS_HIGH;
>  	u32 mr;
>  
> -	if (atmel_spi_is_v2()) {
> +	if (atmel_spi_is_v2(as)) {
>  		/*
>  		 * Always use CSR0. This ensures that the clock
>  		 * switches to the correct idle polarity before we
>  		 * toggle the CS.
>  		 */
>  		spi_writel(as, CSR0, asd->csr);
> -		spi_writel(as, MR, SPI_BF(PCS, 0x0e) | SPI_BIT(MODFDIS)
> -				| SPI_BIT(MSTR));
> +
> +		if (as->pdata->has_wdrbt)
> +			spi_writel(as, MR, SPI_BF(PCS, 0x0e) | SPI_BIT(MSTR)
> +					| SPI_BIT(MODFDIS) | SPI_BIT(WDRBT));
> +		else
> +			spi_writel(as, MR, SPI_BF(PCS, 0x0e)
> +					| SPI_BIT(MSTR) | SPI_BIT(MODFDIS));
> +
>  		mr = spi_readl(as, MR);
>  		gpio_set_value(asd->npcs_pin, active);
>  	} else {
> @@ -321,7 +400,7 @@ static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
>  			asd->npcs_pin, active ? " (low)" : "",
>  			mr);
>  
> -	if (atmel_spi_is_v2() || spi->chip_select != 0)
> +	if (atmel_spi_is_v2(as) || spi->chip_select != 0)
>  		gpio_set_value(asd->npcs_pin, !active);
>  }
>  
> @@ -734,7 +813,7 @@ static int atmel_spi_setup(struct spi_device *spi)
>  	}
>  
>  	/* see notes above re chipselect */
> -	if (!atmel_spi_is_v2()
> +	if (!atmel_spi_is_v2(as)
>  			&& spi->chip_select == 0
>  			&& (spi->mode & SPI_CS_HIGH)) {
>  		dev_dbg(&spi->dev, "setup: can't be active-high\n");
> @@ -743,7 +822,7 @@ static int atmel_spi_setup(struct spi_device *spi)
>  
>  	/* v1 chips start out at half the peripheral bus speed. */
>  	bus_hz = clk_get_rate(as->clk);
> -	if (!atmel_spi_is_v2())
> +	if (!atmel_spi_is_v2(as))
>  		bus_hz /= 2;
>  
>  	if (spi->max_speed_hz) {
> @@ -817,7 +896,7 @@ static int atmel_spi_setup(struct spi_device *spi)
>  		"setup: %lu Hz bpw %u mode 0x%x -> csr%d %08x\n",
>  		bus_hz / scbr, bits, spi->mode, spi->chip_select, csr);
>  
> -	if (!atmel_spi_is_v2())
> +	if (!atmel_spi_is_v2(as))
>  		spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
>  
>  	return 0;
> @@ -921,6 +1000,21 @@ static void atmel_spi_cleanup(struct spi_device *spi)
>  	kfree(asd);
>  }
>  
> +static struct atmel_spi_pdata * __devinit atmel_spi_get_driver_data(
> +					struct platform_device *pdev)
> +{
> +	if (pdev->dev.of_node) {
> +		const struct of_device_id *match;
> +		match = of_match_node(atmel_spi_dt_ids, pdev->dev.of_node);
> +		if (!match)
> +			return NULL;
> +		return (struct atmel_spi_pdata *) match->data;
> +	}
> +
> +	return (struct atmel_spi_pdata *)
> +			platform_get_device_id(pdev)->driver_data;
> +}
> +
>  /*-------------------------------------------------------------------------*/
>  
>  static int atmel_spi_probe(struct platform_device *pdev)
> @@ -987,11 +1081,21 @@ static int atmel_spi_probe(struct platform_device *pdev)
>  	if (ret)
>  		goto out_unmap_regs;
>  
> +	as->pdata = atmel_spi_get_driver_data(pdev);
> +	if (!as->pdata)
> +		goto out_unmap_regs;
> +
>  	/* Initialize the hardware */
>  	clk_enable(clk);
>  	spi_writel(as, CR, SPI_BIT(SWRST));
>  	spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
> -	spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS));
> +
> +	if (as->pdata->has_wdrbt)
> +		spi_writel(as, MR,
> +			SPI_BIT(MSTR) | SPI_BIT(MODFDIS) | SPI_BIT(WDRBT));
> +	else
> +		spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS));
> +
>  	spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
>  	spi_writel(as, CR, SPI_BIT(SPIEN));
>  
> @@ -1084,21 +1188,13 @@ static int atmel_spi_resume(struct platform_device *pdev)
>  #define	atmel_spi_resume	NULL
>  #endif
>  
> -#if defined(CONFIG_OF)
> -static const struct of_device_id atmel_spi_dt_ids[] = {
> -	{ .compatible = "atmel,at91rm9200-spi" },
> -	{ /* sentinel */ }
> -};
> -
> -MODULE_DEVICE_TABLE(of, atmel_spi_dt_ids);
> -#endif
> -
>  static struct platform_driver atmel_spi_driver = {
>  	.driver		= {
>  		.name	= "atmel_spi",
>  		.owner	= THIS_MODULE,
>  		.of_match_table	= of_match_ptr(atmel_spi_dt_ids),
>  	},
> +	.id_table	= atmel_spi_devtypes,
>  	.suspend	= atmel_spi_suspend,
>  	.resume		= atmel_spi_resume,
>  	.probe		= atmel_spi_probe,
> -- 
> 1.7.9.5
> 
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