From: Mason Zhang <[email protected]>
This patch add no_need_unprepare support for spi, if spi src clk is
MAIN PLL, it can keep the clk_prepare and will not cause low power
issue. So we no need do clk_prepare/clk_unprepare in runtime pm,
and it will get better performance, because clk_prepare has called
mutex lock.
In the same way,
clk_get_rate also has called mutex lock, so we moved it to spi_probe.
Signed-off-by: Mason Zhang <[email protected]>
---
drivers/spi/spi-mt65xx.c | 41 +++++++++++++++++++++++++++++++++-------
1 file changed, 34 insertions(+), 7 deletions(-)
diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 976f73b9e299..097625d7915e 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -90,6 +90,8 @@ struct mtk_spi_compatible {
bool enhance_timing;
/* some IC support DMA addr extension */
bool dma_ext;
+ /* some IC no need unprepare SPI clk */
+ bool no_need_unprepare;
};
struct mtk_spi {
@@ -104,6 +106,7 @@ struct mtk_spi {
struct scatterlist *tx_sgl, *rx_sgl;
u32 tx_sgl_len, rx_sgl_len;
const struct mtk_spi_compatible *dev_comp;
+ u32 spi_clk_hz;
};
static const struct mtk_spi_compatible mtk_common_compat;
@@ -135,6 +138,14 @@ static const struct mtk_spi_compatible mt8183_compat = {
.enhance_timing = true,
};
+static const struct mtk_spi_compatible mt6893_compat = {
+ .need_pad_sel = true,
+ .must_tx = true,
+ .enhance_timing = true,
+ .dma_ext = true,
+ .no_need_unprepare = true,
+};
+
/*
* A piece of default chip info unless the platform
* supplies it.
@@ -174,6 +185,9 @@ static const struct of_device_id mtk_spi_of_match[] = {
{ .compatible = "mediatek,mt8192-spi",
.data = (void *)&mt6765_compat,
},
+ { .compatible = "mediatek,mt6893-spi",
+ .data = (void *)&mt6893_compat,
+ },
{}
};
MODULE_DEVICE_TABLE(of, mtk_spi_of_match);
@@ -287,12 +301,11 @@ static void mtk_spi_set_cs(struct spi_device *spi, bool enable)
static void mtk_spi_prepare_transfer(struct spi_master *master,
struct spi_transfer *xfer)
{
- u32 spi_clk_hz, div, sck_time, reg_val;
+ u32 div, sck_time, reg_val;
struct mtk_spi *mdata = spi_master_get_devdata(master);
- spi_clk_hz = clk_get_rate(mdata->spi_clk);
- if (xfer->speed_hz < spi_clk_hz / 2)
- div = DIV_ROUND_UP(spi_clk_hz, xfer->speed_hz);
+ if (xfer->speed_hz < mdata->spi_clk_hz / 2)
+ div = DIV_ROUND_UP(mdata->spi_clk_hz, xfer->speed_hz);
else
div = 1;
@@ -789,7 +802,12 @@ static int mtk_spi_probe(struct platform_device *pdev)
goto err_put_master;
}
- clk_disable_unprepare(mdata->spi_clk);
+ mdata->spi_clk_hz = clk_get_rate(mdata->spi_clk);
+
+ if (mdata->dev_comp->no_need_unprepare)
+ clk_disable(mdata->spi_clk);
+ else
+ clk_disable_unprepare(mdata->spi_clk);
pm_runtime_enable(&pdev->dev);
@@ -857,6 +875,9 @@ static int mtk_spi_remove(struct platform_device *pdev)
mtk_spi_reset(mdata);
+ if (mdata->dev_comp->no_need_unprepare)
+ clk_unprepare(mdata->spi_clk);
+
return 0;
}
@@ -905,7 +926,10 @@ static int mtk_spi_runtime_suspend(struct device *dev)
struct spi_master *master = dev_get_drvdata(dev);
struct mtk_spi *mdata = spi_master_get_devdata(master);
- clk_disable_unprepare(mdata->spi_clk);
+ if (mdata->dev_comp->no_need_unprepare)
+ clk_disable(mdata->spi_clk);
+ else
+ clk_disable_unprepare(mdata->spi_clk);
return 0;
}
@@ -916,7 +940,10 @@ static int mtk_spi_runtime_resume(struct device *dev)
struct mtk_spi *mdata = spi_master_get_devdata(master);
int ret;
- ret = clk_prepare_enable(mdata->spi_clk);
+ if (mdata->dev_comp->no_need_unprepare)
+ ret = clk_enable(mdata->spi_clk);
+ else
+ ret = clk_prepare_enable(mdata->spi_clk);
if (ret < 0) {
dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
return ret;
--
2.18.0
On Tue, 29 Jun 2021 18:08:15 +0800, Mason Zhang wrote:
> This patch add no_need_unprepare support for spi, if spi src clk is
> MAIN PLL, it can keep the clk_prepare and will not cause low power
> issue. So we no need do clk_prepare/clk_unprepare in runtime pm,
> and it will get better performance, because clk_prepare has called
> mutex lock.
> In the same way,
> clk_get_rate also has called mutex lock, so we moved it to spi_probe.
Applied to
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next
Thanks!
[1/2] spi: mediatek: add no_need_unprepare support
commit: 162a31effc4182dd5a0675d9fd0336d5096e0ad3
All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying
to this mail.
Thanks,
Mark