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spi: wpcm-fiu: Add direct map support

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Besides software controlled SPI transfers (UMA, "user mode access"), FIU
also supports a 16 MiB mapping window per attached flash chip.

This patch implements direct mapped read access, to speed up flash reads.

Without direct mapping:

	# time dd if=/dev/mtd0ro of=dump bs=1M
	16+0 records in
	16+0 records out
	real    1m 47.74s
	user    0m 0.00s
	sys     1m 47.75s

With direct mapping:

	# time dd if=/dev/mtd0ro of=dump bs=1M
	16+0 records in
	16+0 records out
	real    0m 30.81s
	user    0m 0.00s
	sys     0m 30.81s

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Link: https://lore.kernel.org/r/20221124191400.287918-4-j.neuschaefer@gmx.net
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Jonathan Neuschäfer 2022-11-24 20:14:00 +01:00 committed by Mark Brown
parent 1f8811a261
commit 9838c18247
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 64 additions and 0 deletions
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64
drivers/spi/spi-wpcm-fiu.c
View File

@ -51,10 +51,16 @@
*/
#define UMA_WAIT_ITERATIONS 100
/* The memory-mapped view of flash is 16 MiB long */
#define MAX_MEMORY_SIZE_PER_CS (16 << 20)
#define MAX_MEMORY_SIZE_TOTAL (4 * MAX_MEMORY_SIZE_PER_CS)
struct wpcm_fiu_spi {
struct device *dev;
struct clk *clk;
void __iomem *regs;
void __iomem *memory;
size_t memory_size;
struct regmap *shm_regmap;
};
@ -367,14 +373,64 @@ static int wpcm_fiu_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
return 0;
}
static int wpcm_fiu_dirmap_create(struct spi_mem_dirmap_desc *desc)
{
struct wpcm_fiu_spi *fiu = spi_controller_get_devdata(desc->mem->spi->controller);
int cs = desc->mem->spi->chip_select;
if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_IN)
return -ENOTSUPP;
/*
* Unfortunately, FIU only supports a 16 MiB direct mapping window (per
* attached flash chip), but the SPI MEM core doesn't support partial
* direct mappings. This means that we can't support direct mapping on
* flashes that are bigger than 16 MiB.
*/
if (desc->info.offset + desc->info.length > MAX_MEMORY_SIZE_PER_CS)
return -ENOTSUPP;
/* Don't read past the memory window */
if (cs * MAX_MEMORY_SIZE_PER_CS + desc->info.offset + desc->info.length > fiu->memory_size)
return -ENOTSUPP;
return 0;
}
static ssize_t wpcm_fiu_direct_read(struct spi_mem_dirmap_desc *desc, u64 offs, size_t len, void *buf)
{
struct wpcm_fiu_spi *fiu = spi_controller_get_devdata(desc->mem->spi->controller);
int cs = desc->mem->spi->chip_select;
if (offs >= MAX_MEMORY_SIZE_PER_CS)
return -ENOTSUPP;
offs += cs * MAX_MEMORY_SIZE_PER_CS;
if (!fiu->memory || offs >= fiu->memory_size)
return -ENOTSUPP;
len = min_t(size_t, len, fiu->memory_size - offs);
memcpy_fromio(buf, fiu->memory + offs, len);
return len;
}
static const struct spi_controller_mem_ops wpcm_fiu_mem_ops = {
.adjust_op_size = wpcm_fiu_adjust_op_size,
.supports_op = wpcm_fiu_supports_op,
.exec_op = wpcm_fiu_exec_op,
.dirmap_create = wpcm_fiu_dirmap_create,
.dirmap_read = wpcm_fiu_direct_read,
};
static void wpcm_fiu_hw_init(struct wpcm_fiu_spi *fiu)
{
/* Configure memory-mapped flash access */
writeb(FIU_BURST_CFG_R16, fiu->regs + FIU_BURST_BFG);
writeb(MAX_MEMORY_SIZE_TOTAL / (512 << 10), fiu->regs + FIU_CFG);
writeb(MAX_MEMORY_SIZE_PER_CS / (512 << 10) | BIT(6), fiu->regs + FIU_SPI_FL_CFG);
/* Deassert all manually asserted chip selects */
writeb(0x0f, fiu->regs + FIU_UMA_ECTS);
}
@ -404,6 +460,14 @@ static int wpcm_fiu_probe(struct platform_device *pdev)
if (IS_ERR(fiu->clk))
return PTR_ERR(fiu->clk);
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "memory");
fiu->memory = devm_ioremap_resource(dev, res);
fiu->memory_size = min_t(size_t, resource_size(res), MAX_MEMORY_SIZE_TOTAL);
if (IS_ERR(fiu->memory)) {
dev_err(dev, "Failed to map flash memory window\n");
return PTR_ERR(fiu->memory);
}
fiu->shm_regmap = syscon_regmap_lookup_by_phandle_optional(dev->of_node, "nuvoton,shm");
wpcm_fiu_hw_init(fiu);