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spi: mxic: Add support for direct mapping
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Implement the ->dirmap_create() and ->dirmap_read/write() hooks to
provide a fast path for read and write accesses.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Zhengxun Li <zhengxunli@mxic.com.tw>
Reviewed-by: Zhengxun Li <zhengxunli@mxic.com.tw>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/linux-mtd/20220127091808.1043392-13-miquel.raynal@bootlin.com
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Miquel Raynal committed Feb 10, 2022
1 parent d1b64bb commit 33fce1d
Showing 1 changed file with 109 additions and 3 deletions.
112 changes: 109 additions & 3 deletions drivers/spi/spi-mxic.c
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Original file line number Diff line number Diff line change
Expand Up @@ -172,6 +172,11 @@ struct mxic_spi {
struct clk *send_dly_clk;
void __iomem *regs;
u32 cur_speed_hz;
struct {
void __iomem *map;
dma_addr_t dma;
size_t size;
} linear;
};

static int mxic_spi_clk_enable(struct mxic_spi *mxic)
Expand Down Expand Up @@ -296,7 +301,8 @@ static u32 mxic_spi_prep_hc_cfg(struct spi_device *spi, u32 flags)
HC_CFG_SLV_ACT(spi->chip_select) | HC_CFG_IDLE_SIO_LVL(1);
}

static u32 mxic_spi_mem_prep_op_cfg(const struct spi_mem_op *op)
static u32 mxic_spi_mem_prep_op_cfg(const struct spi_mem_op *op,
unsigned int data_len)
{
u32 cfg = OP_CMD_BYTES(op->cmd.nbytes) |
OP_CMD_BUSW(fls(op->cmd.buswidth) - 1) |
Expand All @@ -310,7 +316,8 @@ static u32 mxic_spi_mem_prep_op_cfg(const struct spi_mem_op *op)
if (op->dummy.nbytes)
cfg |= OP_DUMMY_CYC(op->dummy.nbytes);

if (op->data.nbytes) {
/* Direct mapping data.nbytes field is not populated */
if (data_len) {
cfg |= OP_DATA_BUSW(fls(op->data.buswidth) - 1) |
(op->data.dtr ? OP_DATA_DDR : 0);
if (op->data.dir == SPI_MEM_DATA_IN) {
Expand Down Expand Up @@ -371,6 +378,77 @@ static int mxic_spi_data_xfer(struct mxic_spi *mxic, const void *txbuf,
return 0;
}

static ssize_t mxic_spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
u64 offs, size_t len, void *buf)
{
struct mxic_spi *mxic = spi_master_get_devdata(desc->mem->spi->master);
int ret;
u32 sts;

if (WARN_ON(offs + desc->info.offset + len > U32_MAX))
return -EINVAL;

writel(mxic_spi_prep_hc_cfg(desc->mem->spi, 0), mxic->regs + HC_CFG);

writel(mxic_spi_mem_prep_op_cfg(&desc->info.op_tmpl, len),
mxic->regs + LRD_CFG);
writel(desc->info.offset + offs, mxic->regs + LRD_ADDR);
len = min_t(size_t, len, mxic->linear.size);
writel(len, mxic->regs + LRD_RANGE);
writel(LMODE_CMD0(desc->info.op_tmpl.cmd.opcode) |
LMODE_SLV_ACT(desc->mem->spi->chip_select) |
LMODE_EN,
mxic->regs + LRD_CTRL);

memcpy_fromio(buf, mxic->linear.map, len);

writel(INT_LRD_DIS, mxic->regs + INT_STS);
writel(0, mxic->regs + LRD_CTRL);

ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
sts & INT_LRD_DIS, 0, USEC_PER_SEC);
if (ret)
return ret;

return len;
}

static ssize_t mxic_spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc,
u64 offs, size_t len,
const void *buf)
{
struct mxic_spi *mxic = spi_master_get_devdata(desc->mem->spi->master);
u32 sts;
int ret;

if (WARN_ON(offs + desc->info.offset + len > U32_MAX))
return -EINVAL;

writel(mxic_spi_prep_hc_cfg(desc->mem->spi, 0), mxic->regs + HC_CFG);

writel(mxic_spi_mem_prep_op_cfg(&desc->info.op_tmpl, len),
mxic->regs + LWR_CFG);
writel(desc->info.offset + offs, mxic->regs + LWR_ADDR);
len = min_t(size_t, len, mxic->linear.size);
writel(len, mxic->regs + LWR_RANGE);
writel(LMODE_CMD0(desc->info.op_tmpl.cmd.opcode) |
LMODE_SLV_ACT(desc->mem->spi->chip_select) |
LMODE_EN,
mxic->regs + LWR_CTRL);

memcpy_toio(mxic->linear.map, buf, len);

writel(INT_LWR_DIS, mxic->regs + INT_STS);
writel(0, mxic->regs + LWR_CTRL);

ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
sts & INT_LWR_DIS, 0, USEC_PER_SEC);
if (ret)
return ret;

return len;
}

static bool mxic_spi_mem_supports_op(struct spi_mem *mem,
const struct spi_mem_op *op)
{
Expand All @@ -388,6 +466,22 @@ static bool mxic_spi_mem_supports_op(struct spi_mem *mem,
return spi_mem_default_supports_op(mem, op);
}

static int mxic_spi_mem_dirmap_create(struct spi_mem_dirmap_desc *desc)
{
struct mxic_spi *mxic = spi_master_get_devdata(desc->mem->spi->master);

if (!mxic->linear.map)
return -EINVAL;

if (desc->info.offset + desc->info.length > U32_MAX)
return -EINVAL;

if (!mxic_spi_mem_supports_op(desc->mem, &desc->info.op_tmpl))
return -EOPNOTSUPP;

return 0;
}

static int mxic_spi_mem_exec_op(struct spi_mem *mem,
const struct spi_mem_op *op)
{
Expand All @@ -404,7 +498,7 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,

writel(HC_EN_BIT, mxic->regs + HC_EN);

writel(mxic_spi_mem_prep_op_cfg(op),
writel(mxic_spi_mem_prep_op_cfg(op, op->data.nbytes),
mxic->regs + SS_CTRL(mem->spi->chip_select));

writel(readl(mxic->regs + HC_CFG) | HC_CFG_MAN_CS_ASSERT,
Expand Down Expand Up @@ -446,6 +540,9 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,
static const struct spi_controller_mem_ops mxic_spi_mem_ops = {
.supports_op = mxic_spi_mem_supports_op,
.exec_op = mxic_spi_mem_exec_op,
.dirmap_create = mxic_spi_mem_dirmap_create,
.dirmap_read = mxic_spi_mem_dirmap_read,
.dirmap_write = mxic_spi_mem_dirmap_write,
};

static const struct spi_controller_mem_caps mxic_spi_mem_caps = {
Expand Down Expand Up @@ -579,6 +676,15 @@ static int mxic_spi_probe(struct platform_device *pdev)
if (IS_ERR(mxic->regs))
return PTR_ERR(mxic->regs);

res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dirmap");
mxic->linear.map = devm_ioremap_resource(&pdev->dev, res);
if (!IS_ERR(mxic->linear.map)) {
mxic->linear.dma = res->start;
mxic->linear.size = resource_size(res);
} else {
mxic->linear.map = NULL;
}

pm_runtime_enable(&pdev->dev);
master->auto_runtime_pm = true;

Expand Down

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