commit 9cd34efbd3 upstream.
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: 37ffab8170 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
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>
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>
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>
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>
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>
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>
Kunihiko Hayashi