Re: [PATCH linux dev-5.3 08/13] mtd: spi-nor: aspeed: add initial support for ast2600

[Andrew Jeffery]

On Wed, 25 Sep 2019, at 22:12, Cédric Le Goater wrote:
> The Segment Registers of the AST2600 have a different encoding. A 1MB
> unit is used and the address range of a flash SPI slave is encoded
> with offsets in the overall controller window. The previous SoC
> AST2400 and AST2500 used absolute addresses. Only bits [27:20] are
> relevant and the end address is an upper bound limit.
> 
> SPI training yet to come.
> 
> Signed-off-by: Cédric Le Goater <clg at kaod.org>

Reviewed-by: Andrew Jeffery <andrew at aj.id.au>

> ---
>  drivers/mtd/spi-nor/aspeed-smc.c | 73 ++++++++++++++++++++++++++++++++
>  1 file changed, 73 insertions(+)
> 
> diff --git a/drivers/mtd/spi-nor/aspeed-smc.c b/drivers/mtd/spi-nor/aspeed-smc.c
> index 4e768092a965..6c5ecea21882 100644
> --- a/drivers/mtd/spi-nor/aspeed-smc.c
> +++ b/drivers/mtd/spi-nor/aspeed-smc.c
> @@ -115,6 +115,39 @@ static const struct aspeed_smc_info spi_2500_info = {
>  	.segment_reg = aspeed_smc_segment_reg,
>  };
>  
> +static u32 aspeed_smc_segment_start_ast2600(
> +	struct aspeed_smc_controller *controller, u32 reg);
> +static u32 aspeed_smc_segment_end_ast2600(
> +	struct aspeed_smc_controller *controller, u32 reg);
> +static u32 aspeed_smc_segment_reg_ast2600(
> +	struct aspeed_smc_controller *controller, u32 start, u32 end);
> +
> +static const struct aspeed_smc_info fmc_2600_info = {
> +	.maxsize = 256 * 1024 * 1024,
> +	.nce = 3,
> +	.hastype = false, /* SPI Only */
> +	.we0 = 16,
> +	.ctl0 = 0x10,
> +	.timing = 0x94,
> +	.set_4b = aspeed_smc_chip_set_4b,
> +	.segment_start = aspeed_smc_segment_start_ast2600,
> +	.segment_end = aspeed_smc_segment_end_ast2600,
> +	.segment_reg = aspeed_smc_segment_reg_ast2600,
> +};
> +
> +static const struct aspeed_smc_info spi_2600_info = {
> +	.maxsize = 256 * 1024 * 1024,
> +	.nce = 2,
> +	.hastype = false,
> +	.we0 = 16,
> +	.ctl0 = 0x10,
> +	.timing = 0x94,
> +	.set_4b = aspeed_smc_chip_set_4b,
> +	.segment_start = aspeed_smc_segment_start_ast2600,
> +	.segment_end = aspeed_smc_segment_end_ast2600,
> +	.segment_reg = aspeed_smc_segment_reg_ast2600,
> +};
> +
>  enum aspeed_smc_ctl_reg_value {
>  	smc_base,		/* base value without mode for other commands */
>  	smc_read,		/* command reg for (maybe fast) reads */
> @@ -249,6 +282,44 @@ static u32 aspeed_smc_segment_reg(
>  {
>  	return (((start >> 23) & 0xFF) << 16) | (((end >> 23) & 0xFF) << 24);
>  }
> +
> +/*
> + * The Segment Registers of the AST2600 have a 1MB unit. The address
> + * range of a flash SPI slave is encoded with offsets in the overall
> + * controller window. The previous SoC AST2400 and AST2500 used
> + * absolute addresses. Only bits [27:20] are relevant and the end
> + * address is an upper bound limit.
> + */
> +
> +#define AST2600_SEG_ADDR_MASK 0x0ff00000
> +
> +static u32 aspeed_smc_segment_start_ast2600(
> +	struct aspeed_smc_controller *controller, u32 reg)
> +{
> +	uint32_t start_offset = (reg << 16) & AST2600_SEG_ADDR_MASK;
> +
> +	return controller->ahb_base_phy + start_offset;
> +}
> +
> +static u32 aspeed_smc_segment_end_ast2600(
> +	struct aspeed_smc_controller *controller, u32 reg)
> +{
> +	uint32_t end_offset = reg & AST2600_SEG_ADDR_MASK;
> +
> +	/* segment is disabled */
> +	if (!end_offset)
> +		return controller->ahb_base_phy;
> +
> +	return controller->ahb_base_phy + end_offset + 0x100000;
> +}
> +
> +static u32 aspeed_smc_segment_reg_ast2600(
> +	struct aspeed_smc_controller *controller, u32 start, u32 end)
> +{
> +    return ((start & AST2600_SEG_ADDR_MASK) >> 16) |
> +	    ((end - 1) & AST2600_SEG_ADDR_MASK);
> +}
> +
>  /*
>   * Switch to turn off read optimisation if needed
>   */
> @@ -536,6 +607,8 @@ static const struct of_device_id aspeed_smc_matches[] = {
>  	{ .compatible = "aspeed,ast2400-spi", .data = &spi_2400_info },
>  	{ .compatible = "aspeed,ast2500-fmc", .data = &fmc_2500_info },
>  	{ .compatible = "aspeed,ast2500-spi", .data = &spi_2500_info },
> +	{ .compatible = "aspeed,ast2600-fmc", .data = &fmc_2600_info },
> +	{ .compatible = "aspeed,ast2600-spi", .data = &spi_2600_info },
>  	{ }
>  };
>  MODULE_DEVICE_TABLE(of, aspeed_smc_matches);
> -- 
> 2.21.0
> 
>