spi: uniphier: switch to use modern name

Change legacy name master to modern name host or controller.

No functional changed.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://msgid.link/r/20231128093031.3707034-19-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230303172041.2103336-84-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: fix reference count leak in uniphier_spi_probe()

The issue happens in several error paths in uniphier_spi_probe().
When either dma_get_slave_caps() or devm_spi_register_master() returns
an error code, the function forgets to decrease the refcount of both
`dma_rx` and `dma_tx` objects, which may lead to refcount leaks.

Fix it by decrementing the reference count of specific objects in
those error paths.

Signed-off-by: Xin Xiong <xiongx18@fudan.edu.cn>
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Reviewed-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Fixes: 28d1dddc59f6 ("spi: uniphier: Add DMA transfer mode support")
Link: https://lore.kernel.org/r/20220125101214.35677-1-xiongx18@fudan.edu.cn
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: Fix a bug that doesn't point to private data correctly

In uniphier_spi_remove(), there is a wrong code to get private data from
the platform device, so the driver can't be removed properly.

The driver should get spi_master from the platform device and retrieve
the private data from it.

Cc: <stable@vger.kernel.org>
Fixes: 5ba155a4d4cc ("spi: add SPI controller driver for UniPhier SoC")
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Link: https://lore.kernel.org/r/1640148492-32178-1-git-send-email-hayashi.kunihiko@socionext.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: Fix a bug that doesn't point to private data correctly

In uniphier_spi_remove(), there is a wrong code to get private data from
the platform device, so the driver can't be removed properly.

The driver should get spi_master from the platform device and retrieve
the private data from it.

Cc: <stable@vger.kernel.org>
Fixes: 5ba155a4d4cc ("spi: add SPI controller driver for UniPhier SoC")
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Link: https://lore.kernel.org/r/1640148492-32178-1-git-send-email-hayashi.kunihiko@socionext.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: Use SPI_MODE_X_MASK

Use SPI_MODE_X_MASK instead of open coded variant.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210510131217.49357-7-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: Use devm_platform_get_and_ioremap_resource() to simplify code

Use devm_platform_get_and_ioremap_resource() to simplify code instead of
platform_get_resource() and devm_ioremap_resource(). This also gets
the resource that the following code uses.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Link: https://lore.kernel.org/r/1589185530-28170-2-git-send-email-hayashi.kunihiko@socionext.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: fix error return code in uniphier_spi_probe()

Fix to return negative error code -EPROBE_DEFER from the DMA probe defer
error handling case instead of 0, as done elsewhere in this function.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Link: https://lore.kernel.org/r/20200429075855.104487-1-weiyongjun1@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: Add DMA transfer mode support

This adds DMA transfer mode support for UniPhier SPI controller.

Since this controller requires simulteaneous transmission and reception,
this indicates SPI_CONTROLLER_MUST_RX and SPI_CONTROLLER_MUST_TX.

Because the supported dma controller has alignment restiction,
there is also a restriction that 'maxburst' parameters in dma_slave_config
corresponds to one word width.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Link: https://lore.kernel.org/r/1577149107-30670-6-git-send-email-hayashi.kunihiko@socionext.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: Add handle_err callback function

This adds master->handle_err() callback function to stop transfer due to
error. The function also resets FIFOs and disables interrupt.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Link: https://lore.kernel.org/r/1577149107-30670-4-git-send-email-hayashi.kunihiko@socionext.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: Change argument of irq functions to private structure

This changes each argument of functions uniphier_irq_{enable,disable}()
to uniphier_spi_priv because these functions are used not only for
spi_device but also for the entire controller.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Link: https://lore.kernel.org/r/1577149107-30670-3-git-send-email-hayashi.kunihiko@socionext.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: Fix FIFO threshold

Rx threshold means the value to inform the receiver when the number of words
in Rx FIFO is equal to or more than the value. Similarly, Tx threshold means
the value to inform the sender when the number of words in Tx FIFO is equal
to or less than the value. The controller triggers the driver to start
the transfer.

In case of Rx, the driver wants to detect that the specified number of words
N are in Rx FIFO, so the value of Rx threshold should be N. In case of Tx,
the driver wants to detect that the same number of spaces as Rx are in
Tx FIFO, so the value of Tx threshold should be (FIFO size - N).

For example, in order for the driver to receive at least 3 words from
Rx FIFO, set 3 to Rx threshold.
+-+-+-+-+-+-+-+-+
| | | | | |*|*|*|
+-+-+-+-+-+-+-+-+

In order for the driver to send at least 3 words to Tx FIFO, because
it needs at least 3 spaces, set 8(FIFO size) - 3 = 5 to Tx threshold.
+-+-+-+-+-+-+-+-+
|*|*|*|*|*| | | |
+-+-+-+-+-+-+-+-+

This adds new function uniphier_spi_set_fifo_threshold() to set
threshold value to the register.

And more, FIFO counts by 'words', so this renames 'fill_bytes' with
'fill_words', and fixes the calculation using bytes_per_words.

Fixes: 37ffab817098 ("spi: uniphier: introduce polling mode")
Cc: Keiji Hayashibara <hayashibara.keiji@socionext.com>
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Link: https://lore.kernel.org/r/1577149107-30670-2-git-send-email-hayashi.kunihiko@socionext.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: use devm_platform_ioremap_resource() to simplify code

Use devm_platform_ioremap_resource() to simplify the code a bit.
This is detected by coccinelle.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20190904135918.25352-33-yuehaibing@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: introduce polling mode

Introduce new polling mode for short size transfer. Either the estimated
transfer time is estimated to exceed 200us, or polling loop actually exceeds
200us, it switches to irq mode.

Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>
Link: https://lore.kernel.org/r/1567488661-11428-4-git-send-email-hayashibara.keiji@socionext.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: remove unnecessary code

This commit removed if() because priv->is_save_param is always true.

Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>
Link: https://lore.kernel.org/r/1567488661-11428-3-git-send-email-hayashibara.keiji@socionext.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: fix wrong register overwrite

When it changes the spi mode, the register is overwritten incorrectly.
This commit fixes this register overwrite.

Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>
Link: https://lore.kernel.org/r/1567488661-11428-2-git-send-email-hayashibara.keiji@socionext.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: Remove dev_err() usage after platform_get_irq()

We don't need dev_err() messages when platform_get_irq() fails now that
platform_get_irq() prints an error message itself when something goes
wrong. Let's remove these prints with a simple semantic patch.

// <smpl>
@@
expression ret;
struct platform_device *E;
@@

ret =
(
platform_get_irq(E, ...)
|
platform_get_irq_byname(E, ...)
);

if ( \( ret < 0 \| ret <= 0 \) )
{
(
-if (ret != -EPROBE_DEFER)
-{ ...
-dev_err(...);
-... }
|
...
-dev_err(...);
)
...
}
// </smpl>

While we're here, remove braces on if statements that only have one
statement (manually).

Cc: Mark Brown <broonie@kernel.org>
Cc: linux-spi@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20190730181557.90391-42-swboyd@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: fix zero-length transfer

The zero-length transfer results in timeout error because
the transfer doesn't start.
This commit modified to return success in this case.

Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: fix timeout error

Timeout error was silently ignored.
This commit adds timeout error handling and modifies return type of
wait_for_completion_timeout().

Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: uniphier: remove unnecessary include headers

This commit removed include headers of linux/of.h and linux/of_platform.h,
because they are not used.

Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: add SPI controller driver for UniPhier SoC

Add SPI controller driver implemented in Socionext UniPhier SoCs.

UniPhier SoCs have two types SPI controllers; SCSSI supports a
single channel, and MCSSI supports multiple channels.
This driver supports SCSSI only.

This controller has 32bit TX/RX FIFO with depth of eight entry,
and supports the SPI master mode only.

This commit is implemented in PIO transfer mode, not DMA transfer.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>