spi: imx/fsl-lpspi: Convert to GPIO descriptors

This converts the two Freescale i.MX SPI drivers
Freescale i.MX (CONFIG_SPI_IMX) and Freescale i.MX LPSPI
(CONFIG_SPI_FSL_LPSPI) to use GPIO descriptors handled in
the SPI core for GPIO chip selects whether defined in
the device tree or a board file.

The reason why both are converted at the same time is
that they were both using the same platform data and
platform device population helpers when using
board files intertwining the code so this gives a cleaner
cut.

The platform device creation was passing a platform data
container from each boardfile down to the driver using
struct spi_imx_master from <linux/platform_data/spi-imx.h>,
but this was only conveying the number of chipselects and
an int * array of the chipselect GPIO numbers.

The imx27 and imx31 platforms had code passing the
now-unused platform data when creating the platform devices,
this has been repurposed to pass around GPIO descriptor
tables. The platform data struct that was just passing an
array of integers and number of chip selects for the GPIO
lines has been removed.

The number of chipselects used to be passed from the board
file, because this number also limits the number of native
chipselects that the platform can use. To deal with this we
just augment the i.MX (CONFIG_SPI_IMX) driver to support 3
chipselects if the platform does not define "num-cs" as a
device property (such as from the device tree). This covers
all the legacy boards as these use <= 3 native chip selects
(or GPIO lines, and in that case the number of chip selects
is determined by the core from the number of available
GPIO lines). Any new boards should use device tree, so
this is a reasonable simplification to cover all old
boards.

The LPSPI driver never assigned the number of chipselects
and thus always fall back to the core default of 1 chip
select if no GPIOs are defined in the device tree.

The Freescale i.MX driver was already partly utilizing
the SPI core to obtain the GPIO numbers from the device tree,
so this completes the transtion to let the core handle all
of it.

All board files and the core i.MX boardfile registration
code is augmented to account for these changes.

This has been compile-tested with the imx_v4_v5_defconfig
and the imx_v6_v7_defconfig.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Shawn Guo <shawnguo@kernel.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Robin Gong <yibin.gong@nxp.com>
Cc: Trent Piepho <tpiepho@impinj.com>
Cc: Clark Wang <xiaoning.wang@nxp.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Link: https://lore.kernel.org/r/20200625200252.207614-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 0 insertions, 33 deletions

diff --git a/include/linux/platform_data/spi-imx.h b/include/linux/platform_data/spi-imx.h
deleted file mode 100644
index 328f670d10bd..000000000000
--- a/include/linux/platform_data/spi-imx.h
+++ /dev/null
@@ -1,33 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-
-#ifndef __MACH_SPI_H_
-#define __MACH_SPI_H_
-
-/*
- * struct spi_imx_master - device.platform_data for SPI controller devices.
- * @chipselect: Array of chipselects for this master or NULL.  Numbers >= 0
- *              mean GPIO pins, -ENOENT means internal CSPI chipselect
- *              matching the position in the array.  E.g., if chipselect[1] =
- *              -ENOENT then a SPI slave using chip select 1 will use the
- *              native SS1 line of the CSPI.  Omitting the array will use
- *              all native chip selects.
-
- *              Normally you want to use gpio based chip selects as the CSPI
- *              module tries to be intelligent about when to assert the
- *              chipselect:  The CSPI module deasserts the chipselect once it
- *              runs out of input data.  The other problem is that it is not
- *              possible to mix between high active and low active chipselects
- *              on one single bus using the internal chipselects.
- *              Unfortunately, on some SoCs, Freescale decided to put some
- *              chipselects on dedicated pins which are not usable as gpios,
- *              so we have to support the internal chipselects.
- *
- * @num_chipselect: If @chipselect is specified, ARRAY_SIZE(chipselect),
- *                  otherwise the number of native chip selects.
- */
-struct spi_imx_master {
-	int	*chipselect;
-	int	num_chipselect;
-};
-
-#endif /* __MACH_SPI_H_*/