[ Upstream commit 730bbfaf7d4890bd99e637db7767dc68cfeb24e7 ]

The effective SPI clock frequency should never exceed speed_hz
otherwise this might result in undefined behavior of the SPI device.

Currently the scldiv calculation could violate this constraint.
For the example parameters perclk_rate = 24 MHz and speed_hz = 7 MHz,
the function fsl_lpspi_set_bitrate will determine perscale = 0 and
scldiv = 1, which is a effective SPI clock of 8 MHz.

So fix this by rounding up the quotient of perclk_rate and speed_hz.
While this never change within the loop, we can pull this out.

Fixes: 5314987de5e5 ("spi: imx: add lpspi bus driver")
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://patch.msgid.link/20240804113611.83613-1-wahrenst@gmx.net
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 2fa98705a9289c758b6154a22174aa8d4041a285 ]

- replace the array with the shift operation
- remove the extra comparing operation.

Signed-off-by: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>
Link: https://lore.kernel.org/r/20200220141143.3902922-2-oleksandr.suvorov@toradex.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Stable-dep-of: 730bbfaf7d48 ("spi: spi-fsl-lpspi: Fix scldiv calculation")
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 77736a98b859e2c64aebbd0f90b2ce4b17682396 ]

Add a error info when set a speed which greater than half of per-clk of
spi module.

The minimum SCK period is 2 cycles(CCR[SCKDIV]). So the maximum transfer
speed is half of spi per-clk.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Stable-dep-of: 730bbfaf7d48 ("spi: spi-fsl-lpspi: Fix scldiv calculation")
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit f5e5afdb0e56e81123e02b6a64dd32adc19a90d4 ]

Add both ipg and per clock for lpspi to support i.MX8QM/QXP boards.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Stable-dep-of: 730bbfaf7d48 ("spi: spi-fsl-lpspi: Fix scldiv calculation")
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit cf86874bb9bdb99ba3620428b59b0408fbc703d0 ]

Configure watermark to change with the length of the sent data.
Support LPSPI sending message shorter than tx/rxfifosize.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Stable-dep-of: 730bbfaf7d48 ("spi: spi-fsl-lpspi: Fix scldiv calculation")
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit bcd87317aae26b9ac497cbc1232783aaea1aeed4 ]

Add slave mode support to the fsl-lpspi driver, only in PIO mode.

For now, there are some limitations for slave mode transmission:
1. The stale data in RXFIFO will be dropped when the Slave does any new
   transfer.
2. One transfer can be finished only after all transfer->len data been
   transferred to master device
3. Slave device only accepts transfer->len data. Any data longer than
   this from master device will be dropped. Any data shorter than this
   from master will cause LPSPI to stuck due to mentioned limitation 2.
4. Only PIO transfer is supported in Slave Mode.

Wire connection:
GND, SCK, MISO(to MISO of slave), MOSI(to MOSI of slave), SCS

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Stable-dep-of: 730bbfaf7d48 ("spi: spi-fsl-lpspi: Fix scldiv calculation")
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 07d71557494c05b0651def1651bf6d7e7f47bbbb ]

In order to enable the slave mode and make the code more readable,
replace all related structure names and object names which is
named "master" with "controller".

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Stable-dep-of: 730bbfaf7d48 ("spi: spi-fsl-lpspi: Fix scldiv calculation")
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit ce1dac560a74220f2e53845ec0723b562288aed4 ]

While in commit 2dd33f9cec90 ("spi: imx: support DMA for imx35") it was
claimed that DMA works on i.MX25, i.MX31 and i.MX35 the respective
device trees don't add DMA channels. The Reference manuals of i.MX31 and
i.MX25 also don't mention the CSPI core being DMA capable. (I didn't
check the others.)

Since commit e267a5b3ec59 ("spi: spi-imx: Use dev_err_probe for failed
DMA channel requests") this results in an error message

	spi_imx 43fa4000.spi: error -ENODEV: can't get the TX DMA channel!

during boot. However that isn't fatal and the driver gets loaded just
fine, just without using DMA.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://patch.msgid.link/20240508095610.2146640-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 9f788ba457b45b0ce422943fcec9fa35c4587764 ]

There is no need to set the DMA mapped flag of the message if it has
no mapped transfers. Moreover, it may give the code a chance to take
the wrong paths, i.e. to exercise DMA related APIs on unmapped data.
Make __spi_map_msg() to bail earlier on the above mentioned cases.

Fixes: 99adef310f68 ("spi: Provide core support for DMA mapping transfers")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://msgid.link/r/20240522171018.3362521-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit a20ad45008a7c82f1184dc6dee280096009ece55 ]

The TX buffer in spi_transfer can be a NULL pointer, so the interrupt
handler may end up writing to the invalid memory and cause crashes.

Add a check to trans->tx_buf before using it.

Fixes: 1ce24864bff4 ("spi: mediatek: Only do dma for 4-byte aligned buffers")
Signed-off-by: Fei Shao <fshao@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://msgid.link/r/20240321070942.1587146-2-fshao@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>