Commit graph

549 commits

Author SHA1 Message Date
Masahiro Yamada
186c133444 pinctrl: uniphier: allow to have pinctrl node under syscon node
Currently, the UniPhier pinctrl driver itself is a syscon, but it
turned out much more reasonable to make it a child node of a syscon
because our syscon node consists of a bunch of system configuration
registers, not only pinctrl, but also phy, and misc registers.
It is difficult to split the node.  This commit allows to migrate to
the new DT structure.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-07-02 05:44:29 +09:00
Masahiro Yamada
aac641bcf4 pinctrl: uniphier: remove unneeded pin group nand_cs1
This SoC does not support NAND CS1.  This place-holder is no longer
necessary.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-06-30 23:49:26 +09:00
Masahiro Yamada
69da34c073 pinctrl: uniphier: fix NAND pin-mux setting for PH1-LD11/LD20
My mistake in the initial support patch.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-06-30 23:49:26 +09:00
Masahiro Yamada
4d1065c8d8 pinctrl: uniphier: remove wrong pin-mux functions for ProXstream2
These are pin group names, not function names.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-06-30 23:49:26 +09:00
Tom Rini
d77fa2ff76 Merge http://git.denx.de/u-boot-samsung
Signed-off-by: Tom Rini <trini@konsulko.com>

Conflicts:
	configs/peach-pi_defconfig
	configs/peach-pit_defconfig
2016-06-06 13:39:43 -04:00
Sjoerd Simons
70f7a2cdac rockchip: rk3288: pinctrl: support more pins
The rgmii_pins node in rk3288.dtsi configures 15 pins. Increase the size
of the cell array to accomedate that, otherwise only the first 10 get
configured.

Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Reviewed-by: Simon Glass <sjg@chromium.org>
2016-05-27 09:00:48 -06:00
Thomas Abraham
16ca80adc5 pinctrl: Add pinctrl driver support for Exynos7420 SoC
Add pinctrl driver support for Samsung's Exynos7420 SoC. The changes
have been split into Exynos7420 specific and common Exynos specific
portions so that this implementation is reusable on other Exynos
SoCs as well.

The Exynos pinctrl driver supports only device tree based pin
configuration. The bindings used are similar to the ones used in the
linux kernel.

Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Minkyu Kang <mk7.kang@samsung.com>
Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Minkyu Kang <mk7.kang@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
2016-05-25 10:00:18 +09:00
Thomas Abraham
ac98527313 pinctrl: add the DM_UC_FLAG_SEQ_ALIAS flag for numbering the devices
It is possible to have multiple pin controllers in the system. Use the
DM_UC_FLAG_SEQ_ALIAS flag so that the pinctrl instances are assigned
a sequence number.

Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
2016-05-25 10:00:18 +09:00
Wills Wang
c102453aeb drivers: pinctrl: Add simple pinctrl driver for Qualcomm/Atheros qca953x.
This is a simple pinctrl driver, it just support uart and spi pin-mux now.

Signed-off-by: Wills Wang <wills.wang@live.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
[fixed typo in commit subject line]
Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
2016-05-21 01:25:50 +02:00
Wills Wang
a79d0643f4 drivers: pinctrl: Add simple pinctrl driver for Qualcomm/Atheros ar933x.
This is a simple pinctrl driver, it just support uart and spi pin-mux now.

Signed-off-by: Wills Wang <wills.wang@live.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
[fixed typo in commit subject line]
Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
2016-05-21 01:25:50 +02:00
Masahiro Yamada
740314326d pinctrl: uniphier: fix NAND and SD pin-mux settings for PH1-LD11/LD20
I found many mistakes in the initial version.

Fixes: 8a3328c209 ("pinctrl: uniphier: support UniPhier PH1-LD20 pinctrl driver")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-04-24 09:53:54 +09:00
Masahiro Yamada
ac13ce49a4 pinctrl: uniphier: rename function/array names
Make function/array names match the file names for consistency.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-04-24 09:53:54 +09:00
Masahiro Yamada
6105aa2f2a pinctrl: uniphier: support UniPhier PH1-LD11 pinctrl driver
The pinmux of PH1-LD11 is almost a subset of that of PH1-LD20
(as far as used in boot-loader), so this commit makes the driver
shared between the two SoCs.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-04-01 00:57:19 +09:00
Masahiro Yamada
8a3328c209 pinctrl: uniphier: support UniPhier PH1-LD20 pinctrl driver
Add pin configuration and pinmux support for UniPhier PH1-LD20 SoC.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-04-01 00:57:15 +09:00
Masahiro Yamada
3b05b5f0e4 pinctrl: uniphier: support per-pin input enable for new SoCs
Upcoming new pinctrl drivers for PH1-LD11 and PH-LD20 support input
signal gating for each pin.  (While, existing ones only support it
per pin-group.)  This commit prepares the core part for that.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-04-01 00:56:07 +09:00
Masahiro Yamada
8cc92b996d pinctrl: uniphier: introduce capability flag
The core part of the UniPhier pinctrl driver needs to support a new
capability for upcoming UniPhier ARMv8 SoCs.  This sometimes happens
because pinctrl drivers include really SoC-specific stuff.

This commit intends to tidy up SoC-specific parameters of the existing
drivers before adding new ones.  Having flags would be better than
adding new members every time a new SoC-specific capability comes up.

At this time, there is one flag, UNIPHIER_PINCTRL_CAPS_DBGMUX_SEPARATE.
This capability (I'd say rather quirk) was added for PH1-Pro4 and
PH1-Pro5 as requirement from our customer.  For those SoCs, one pin-mux
setting is controlled by the combination of two separate registers; the
LSB bits at register offset (8 * N) and the MSB bits at (8 * N + 4).
Because it is impossible to update two separate registers atomically,
the LOAD_PINCTRL register should be set in order to make the pin-mux
settings really effective.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-04-01 00:54:00 +09:00
Masahiro Yamada
510454db04 pinctrl: uniphier: use devm_get_addr() to get base address
Currently, fdtdec_get_addr_size() does not support the address
translation, so it cannot handle device trees with non-straight
"ranges" properties.  (This would be a problem with DTS for UniPhier
ARMv8 SoCs.)

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-04-01 00:17:25 +09:00
Masahiro Yamada
ea65c98050 ARM: uniphier: drop PH1- prefix from CONFIG options and file names
The current CONFIG names like "CONFIG_ARCH_UNIPHIER_PH1_PRO4" is too
long.  It would not hurt to drop "PH1_" because "UNIPHIER_" already
well specifies the SoC family.  Also, rename files for consistency.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-03-24 01:42:13 +09:00
Masahiro Yamada
1d22c4b1bd pinctrl: uniphier: guard uniphier directory with CONFIG_PINCTRL_UNIPHIER
CONFIG_PINCTRL_UNIPHIER is more suitable than CONFIG_ARCH_UNIPHIER
to guard the drivers/pinctrl/uniphier directory.

The current CONFIG_PINCTRL_UNIPHIER_CORE is a bit long, so rename it
into CONFIG_PINCTRL_UNIPHIER.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-03-09 01:11:04 +09:00
Masahiro Yamada
fdd15b6a86 pinctrl: uniphier: set input-enable before pin-muxing
While IECTRL is disabled, input signals are pulled-down internally.
If pin-muxing is set up first, glitch signals (Low to High transition)
might be input to hardware blocks.

Bad case scenario:
[1] The hardware block is already running before pinctrl is handled.
   (the reset is de-asserted by default or by a firmware, for example)
[2] The pin-muxing is set up.  The input signals to hardware block
   are pulled-down by the chip-internal biasing.
[3] The pins are input-enabled.  The signals from the board reach the
    hardware block.

Actually, one invalid character is input to the UART blocks for such
SoCs as PH1-LD4, PH1-sLD8, where UART devices start to run at the
power on reset.

To avoid such problems, pins should be input-enabled before muxing.

[ ported from Linux commit bac7f4c1bf5e7c6ccd5bb71edc015b26c77f7460 ]

Fixes: 5dc626f836 ("pinctrl: uniphier: add UniPhier pinctrl core support")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2016-03-09 01:10:52 +09:00
Peng Fan
c4068dfb31 pinctrl: imx: Support i.MX7D
Introudce i.MX7 pinctrl driver support.
For now only i.MX7D supported.
There are two iomux controllers in i.MX7D, iomuxc and iomuxc_lpsr.
To iomuxc_lpsr, ZERO_OFFSET_VALID is set, means offset of mux_reg
and conf_reg can begin at 0.

Signed-off-by: Peng Fan <van.freenix@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2016-02-21 11:25:29 +01:00
Peng Fan
745df68d36 pinctrl: imx: Introduce pinctrl driver for i.MX6
Introduce pinctrl for i.MX6
1. pinctrl-imx.c is for common usage. It's used by i.MX6/7.
2. Add PINCTRL_IMX PINCTRL_IMX6 Kconfig entry.
3. To the pinctrl_ops implementation, only set_state is implemented.
   To i.MX6/7, the pinctrl dts entry is as following:
&iomuxc {
        pinctrl-names = "default";

        pinctrl_csi1: csi1grp {
                fsl,pins = <
                MX6UL_PAD_CSI_MCLK__CSI_MCLK            0x1b088
                MX6UL_PAD_CSI_PIXCLK__CSI_PIXCLK        0x1b088
                MX6UL_PAD_CSI_VSYNC__CSI_VSYNC          0x1b088
                >;
        };

        [.....]
};
  there is no property named function or groups. So pinctrl_generic_set_state
  can not be used here.
5. This driver is a simple implementation for i.mx iomux controller,
   only parse the fsl,pins property and write value to registers.
6. With DEBUG enabled, we can see log when "i2c bus 0":
   "
   set_state_simple op missing
   imx_pinctrl_set_state: i2c1grp
   mux_reg 0x14c, conf_reg 0x3bc, input_reg 0x5d8, mux_mode 0x0, input_val 0x1, config_val 0x4000007f
   write mux: offset 0x14c val 0x10
   select_input: offset 0x5d8 val 0x1
   write config: offset 0x3bc val 0x7f
   mux_reg 0x148, conf_reg 0x3b8, input_reg 0x5d4, mux_mode 0x0, input_val 0x1, config_val 0x4000007f
   write mux: offset 0x148 val 0x10
   select_input: offset 0x5d4 val 0x1
   write config: offset 0x3b8 val 0x7f
   "
   this means imx6 pinctrl driver works as expected.

Signed-off-by: Peng Fan <van.freenix@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2016-02-21 11:23:48 +01:00
Purna Chandra Mandal
5f266c60bf drivers: pinctrl: Add pinctrl driver for Microchip PIC32.
In PIC32 pin-controller is a combined gpio-controller, pin-mux and
pin-config module. Remappable peripherals are assigned pins through
per-pin based muxing logic. And pin configuration are performed on
specific port registers which are shared along with gpio controller.
Note, non-remappable peripherals have default pins assigned thus
require no muxing.

Signed-off-by: Purna Chandra Mandal <purna.mandal@microchip.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2016-02-01 22:14:00 +01:00
Masahiro Yamada
84b8bf6d5d bug.h: move BUILD_BUG_* defines to include/linux/bug.h
BUILD_BUG_* macros have been defined in several headers.  It would
be nice to collect them in include/linux/bug.h like Linux.

This commit is cherry-picking useful macros from include/linux/bug.h
of Linux 4.4.

I did not import BUILD_BUG_ON_MSG() because it would not work if it
is used with include/common.h in U-Boot.  I'd like to postpone it
until the root cause (the "error()" macro in include/common.h causes
the name conflict with "__attribute__((error()))") is fixed.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
2016-01-25 10:39:59 -05:00
Simon Glass
318922b30f rockchip: rk3288: pinctrl: Fix HDMI pinctrl
Since the device tree does not specify the EDID pinctrl option for HDMI we
must set it manually. Fix the driver to handle this.

Signed-off-by: Simon Glass <sjg@chromium.org>
2016-01-21 20:42:37 -07:00
Simon Glass
78a10b6656 rockchip: pinctrl: Implement the get_gpio_mux() method
Implement this so that the GPIO command will be able to report whether a
GPIO is used for input or output.

Signed-off-by: Simon Glass <sjg@chromium.org>
2016-01-21 20:42:35 -07:00
Simon Glass
63c52648e4 rockchip: pinctrl: Reduce the size for SPL
This file has many features that are not needed by SPL. Use #ifdef to
remove the unused features and reduce the code size.

Signed-off-by: Simon Glass <sjg@chromium.org>
2016-01-21 20:42:35 -07:00
Simon Glass
77eaa19e73 dm: pinctrl: Add a way for a GPIO driver to obtain a pin function
GPIO drivers want to be able to show if a pin is enabled for input, output,
or is being used by another function. Some drivers can easily find this
and the code is included in the driver. For some SoCs this is more complex.
Conceptually this should be handled by pinctrl rather than GPIO. Most
pinctrl drivers will have this feature anyway.

Add a method by which a GPIO driver can obtain the pin mux value given a
GPIO reference. This avoids repeating the code in two places.

Signed-off-by: Simon Glass <sjg@chromium.org>
2016-01-21 20:42:35 -07:00
Simon Glass
bea705c993 rockchip: pinctrl: Add a full pinctrl driver
We can make use of the device tree to configure pinctrl settings. Add this
support for the driver so we can use it in U-Boot proper.

Signed-off-by: Simon Glass <sjg@chromium.org>
2016-01-21 20:42:35 -07:00
Simon Glass
a4275f5e52 rockchip: Convert the PMU IOMUX registers into an array
This is easier to deal with when using generic code since it allows us to
use a register index instead of naming each register.

Adjust it, adding an enum to improve readability.

Signed-off-by: Simon Glass <sjg@chromium.org>
2016-01-21 20:42:34 -07:00
Simon Glass
52db39a22b dm: pinctrl: Add a function to parse PIN_CONFIG flags
Add a function which produces a flags word from a few common PIN_CONFIG
settings. This is useful for simple pinctrl drivers that don't need to worry
about drive strength, etc.

Signed-off-by: Simon Glass <sjg@chromium.org>
2016-01-21 20:42:34 -07:00
Jeffy Chen
9d19e5d3da rockchip: rk3036: Bind GPIO banks
Call dm_scan_fdt_node() in rk3036 pinctrl uclass binding.

Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
2016-01-21 20:04:04 -07:00
Simon Glass
5589a81829 pinctrl: Avoid binding all pinconfig nodes before relocation
This can create a large number of pinctrl devices. It chews up early
malloc() memory and takes time. Only bind those which are marked as needed
before relocation.

Signed-off-by: Simon Glass <sjg@chromium.org>
2016-01-20 19:06:22 -07:00
huang lin
49ecaa928f rockchip: rk3036: Add pinctrl driver
Add a driver which support pin multiplexing setup for rk3036

Signed-off-by: Lin Huang <hl@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
2015-12-01 08:07:22 -07:00
Tom Rini
da58dec866 Various Makefiles: Add SPDX-License-Identifier tags
After consulting with some of the SPDX team, the conclusion is that
Makefiles are worth adding SPDX-License-Identifier tags too, and most of
ours have one.  This adds tags to ones that lack them and converts a few
that had full (or in one case, very partial) license blobs into the
equivalent tag.

Cc: Kate Stewart <kstewart@linuxfoundation.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
2015-11-10 09:19:52 -05:00
Masahiro Yamada
8497ccc4c2 ARM: uniphier: rename CONFIG_MACH_* to CONFIG_ARCH_UNIPHIER_*
I want these prefixed with CONFIG_ARCH_UNIPHIER_ to clarify
they belong to UniPhier SoC family.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2015-09-25 00:27:53 +09:00
Masahiro Yamada
080b7a5b45 pinctrl: uniphier: add UniPhier PH1-LD6b pinctrl driver
Add pin configuration and pinmux support for UniPhier PH1-LD6b SoC.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2015-09-25 00:27:47 +09:00
Masahiro Yamada
833de5fafb pinctrl: uniphier: add UniPhier ProXstream2 pinctrl driver
Add pin configuration and pinmux support for UniPhier ProXstream2
SoC.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2015-09-25 00:26:27 +09:00
Masahiro Yamada
b82ca82ed2 pinctrl: uniphier: add UniPhier PH1-Pro5 pinctrl driver
Add pin configuration and pinmux support for UniPhier PH1-Pro5 SoC.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2015-09-25 00:25:29 +09:00
Masahiro Yamada
06b2ae5890 pinctrl: uniphier: add UniPhier PH1-sLD8 pinctrl driver
Add pin configuration and pinmux support for UniPhier PH1-sLD8 SoC.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2015-09-25 00:24:30 +09:00
Masahiro Yamada
a343812461 pinctrl: uniphier: add UniPhier PH1-Pro4 pinctrl driver
Add pin configuration and pinmux support for UniPhier PH1-Pro4 SoC.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2015-09-25 00:23:15 +09:00
Masahiro Yamada
e4410e8207 pinctrl: uniphier: add UniPhier PH1-LD4 pinctrl driver
Add pin configuration and pinmux support for UniPhier PH1-LD4 SoC.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2015-09-25 00:21:13 +09:00
Masahiro Yamada
5dc626f836 pinctrl: uniphier: add UniPhier pinctrl core support
The core support for the pinctrl drivers for all the UniPhier SoCs.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2015-09-23 23:21:32 +09:00
Masahiro Yamada
8a5f6129d1 pinctrl: move dm_scan_fdt_node() out of pinctrl uclass
Commit c5acf4a2b3 ("pinctrl: Add the concept of peripheral IDs")
added some additional change that was not mentioned in the git-log.

That commit added dm_scan_fdt_node() in the pinctrl uclass binding.
It should be handled by the simple-bus driver or the low-level
driver, not by the pinctrl framework.

I guess Simon's motivation was to bind GPIO banks located under the
Rockchip pinctrl device.  It is true some chips have sub-devices
under their pinctrl devices, but it is basically SoC-specific matter.

This commit partly reverts commit c5acf4a2b3 to keep the only
pinctrl-generic features in the uclass.  The dm_scan_fdt_node()
should be called from the rk3288_pinctrl driver.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
2015-09-19 15:42:15 -06:00
Simon Glass
bb4e4a5d96 rockchip: rk3288: Add pinctrl driver
Add a driver which supports pin multiplexing setup for the most commonly
used peripherals.

Signed-off-by: Simon Glass <sjg@chromium.org>
2015-09-02 21:28:24 -06:00
Simon Glass
c5acf4a2b3 pinctrl: Add the concept of peripheral IDs
My original pinctrl patch operating using a peripheral ID enum. This was
shared between pinmux and clock and provides an easy way to specify a device
that needs to be controlled, even it is does not (yet) have a driver within
driver model.

Masahiro's new simple pinctrl gets around this by providing a
set_state_simple() pinctrl method. By passing a device to that call the
peripheral ID becomes unnecessary. If the driver needs it, it can calculate
it itself and use it internally.

However this does not solve the problem for peripheral clocks. The 'pure'
solution would be to pass a driver to the clock uclass also. But this
requires that all devices should have a driver, and a struct udevide. Also
a key optimisation of the clock uclass is allowing a peripheral clock to
be set even when there is no device for that clock.

There may be a better way to achive the same goal, but for now it seems
expedient to add in peripheral ID to the pinctrl uclass. Two methods are
added - one to get the peripheral ID and one to select it. The existing
set_state_simple() is effectively the union of these.

Signed-off-by: Simon Glass <sjg@chromium.org>
2015-09-02 21:28:22 -06:00
Simon Glass
458a070076 pinctrl: Add help text to Kconfig
The pinctrl Kconfig options should have help messages. Add this to a few
options.

Signed-off-by: Simon Glass <sjg@chromium.org>
2015-09-02 21:28:22 -06:00
Masahiro Yamada
9c6a3c6772 pinctrl: sandbox: add sandbox pinctrl driver
This driver actually does nothing but test pinctrl uclass, and
demonstrate how things work.

To try this driver, uncomment /* #define DEBUG */ in the
drivers/pinctrl/pinctrl-sandbox.c, and debug messages will be
displayed.

  DRAM:  128 MiB
  sandbox pinmux: group = 1 (serial_a), function = 1 (serial)
  Using default environment

  In:    cros-ec-keyb
  Out:   lcd
  Err:   lcd
  Net:   Net Initialization Skipped
  eth0: eth@10002000, eth1: eth@80000000, eth5: eth@90000000
  => i2c dev 0
  Setting bus to 0
  sandbox pinmux: group = 0 (i2c), function = 0 (i2c)
  sandbox pinconf: group = 0 (i2c), param = 3, arg = 1

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Simon Glass <sjg@chromium.org>
2015-08-31 07:57:29 -06:00
Masahiro Yamada
d90a5a30de pinctrl: add pin control uclass support
This creates a new framework for handling of pin control devices,
i.e. devices that control different aspects of package pins.

This uclass handles pinmuxing and pin configuration; pinmuxing
controls switching among silicon blocks that share certain physical
pins, pin configuration handles electronic properties such as pin-
biasing, load capacitance etc.

This framework can support the same device tree bindings, but if you
do not need full interface support, you can disable some features to
reduce memory foot print.  Typically around 1.5KB is necessary to
include full-featured uclass support on ARM board (CONFIG_PINCTRL +
CONFIG_PINCTRL_FULL + CONFIG_PINCTRL_GENERIC + CONFIG_PINCTRL_PINMUX),
for example.

We are often limited on code size for SPL.  Besides, we still have
many boards that do not support device tree configuration.  The full
pinctrl, which requires OF_CONTROL, does not make sense for those
boards.  So, this framework also has a Do-It-Yourself (let's say
simple pinctrl) interface.  With CONFIG_PINCTRL_FULL disabled, the
uclass itself provides no systematic mechanism for identifying the
peripheral device, applying pinctrl settings, etc.  They must be
done in each low-level driver.  In return, you can save much memory
footprint and it might be useful especially for SPL.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Simon Glass <sjg@chromium.org>
2015-08-31 07:57:29 -06:00