Commit graph

43251 commits

Author SHA1 Message Date
Eric Gao
df8fe99cf2 rockchip: dts: Add mipi dsi support for rk3399
Add dts config for mipi display, include vop, mipi controller, panel, backlight
. And Enable rk808 for lcd_3v3 in another patch.

Signed-off-by: Eric Gao <eric.gao@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
2017-05-10 13:37:22 -06:00
Eric Gao
028d684901 rockchip: board: evb_rk3399: initialize pwm0 for dispaly backlight
Enable pwm0 for display of rk3399 evb board. The PWM do not have decicated
interrupt number in dts and can not get periph_id by pinctrl framework. So
init them here.

Signed-off-by: Eric Gao <eric.gao@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:22 -06:00
Eric Gao
c34bd8b820 rockchip: video: vop: Reserve enough space for mipi dispaly
plat->size here is used to reserve frame buffer space befor relocation.
our mipi panel use 24 bitwidth, and vop require 32bit align. So the frame
buffer size should be at least 1920*1200*32/8.

Signed-off-by: Eric Gao <eric.gao@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:22 -06:00
Eric Gao
8aed0d7751 rockchip: video: vop: Set different bitwidth for different display mode
Because the bitwidth is different for different display mode, so we need
to set them according to demand.

Signed-off-by: Eric Gao <eric.gao@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:22 -06:00
Eric Gao
9f819931e0 rockchip: video: vop: Add mipi display mode for rk3399
Add mipi display mode for rk3399 vop, so that we can use mipi panel
for display.

Signed-off-by: Eric Gao <eric.gao@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:22 -06:00
Eric Gao
e07e5bde7c rockchip: video: vop: Fix rk_display_init() return error
It's caused by the difference of clk_set_rate function implement between
rk3288 andd rk3399.

clk_set_rate() of rk3288 return 0 in normal condition.
clk_set_rate() of rk3399 return input parameter in normal condition.

So check clk_set_rate's return value by IS_ERR_VALUE.

Signed-off-by: Eric Gao <eric.gao@rock-chips.com>
2017-05-10 13:37:22 -06:00
Eric Gao
1c3984041c rockchip: video: Add mipi driver support for rockchip soc
Add basic driver for mipi display on rockchip soc platform.

Signed-off-by: Eric Gao <eric.gao@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:22 -06:00
Eric Gao
858f6368af rockchip: include: grf: Add GRF register declaration for mipi dsi
Add GRF register declaration for mipi dsi.

Signed-off-by: Eric Gao <eric.gao@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
2017-05-10 13:37:22 -06:00
Jacob Chen
453c5a927c power: rk808: rename to rk8xx
Since this driver can be used for rk8xx series pmic,
let's rename rk808 to rk8xx, to make it clear.

Configs parts are done by sed -i "s/RK808/RK8XX/g" `grep RK808 -lr ./`

Signed-off-by: Jacob Chen <jacob-chen@iotwrt.com>
2017-05-10 13:37:22 -06:00
Jacob Chen
eff4ca7285 power: regulator: rk808: add rk818 support
Add support for the rk818 regulator. The regulator module consists
of 4 DCDCs, 9 LDOs, 1 switch and 1 BOOST converter which is used to
power OTG and HDMI5V.

Signed-off-by: Jacob Chen <jacob-chen@iotwrt.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:22 -06:00
Jacob Chen
b049acc902 power: regulator: rk808: replace vsel_bits with vsel_mask
Using mask is more flexible than bits.

Signed-off-by: Jacob Chen <jacob-chen@iotwrt.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:22 -06:00
Jacob Chen
d77af8a8c9 power: pmic: rk808: add RK818 support
The RK818 chip is a Power Management IC (PMIC) for multimedia and handheld
devices.

For boards use rk818, the input current should be set in the early stage, before
ddr initialization.

Signed-off-by: Jacob Chen <jacob-chen@iotwrt.com>
2017-05-10 13:37:22 -06:00
Jacob Chen
1daa93c0b4 power: pmic: append rk818 regs to rk808
Both RK808 and RK818 chips are using a similar register map,
so we can reuse them.

I have also add reg prefix to exist registers, to keep them same style.

Signed-off-by: Jacob Chen <jacob-chen@iotwrt.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:22 -06:00
Jonas Karlman
ecc3bd73b3 rockchip: tinker: set ethaddr in late init
Set ethernet mac address in late init for Tinker Board,
prevents getting a random mac address each boot.

Read mac address from eeprom, first 6 bytes from m24c08@50.
Same as /etc/init.d/rockchip.sh on Tinker OS.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:22 -06:00
Jonas Karlman
8880efbd1f i2c_eeprom: add read and write functions
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:22 -06:00
Philipp Tomsich
26e2e404b7 rockchip: pinctrl: rk3399: add support for the HDMI I2C pins
To add HDMI support for the RK3399, this commit provides the needed
pinctrl functionality to configure the HDMI I2C pins (used for reading
the screen's EDID).

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
ffc1fac549 rockchip: clk: rk3399: allow requests for HDMI clocks
This allows requests (via the DTS) for PCLK_HDMI_CTRL/PCLK_VIO_GRF,
which are clock gates in the HDMI output path for the RK3399.

As these are enabled by default (i.e. after reset), we don't implement
any logic to actively open/close these clock gates and simply assume
that their reset-default has not been changed.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
e92e580350 rockchip: ARM64: puma-rk3399: get DRAM size from DMC init
With the RK3399 DRAM controller (DMC) driver providing all the
infrastructure, retrieve the DRAM size from the DMC init in the
board-specific code (instead of hard-coding) for the RK3399-Q7 (Puma).

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
a70feb4620 rockchip: clk: rk3399: allow requests for PCLK_EFUSE1024NS
The (non-secure) efuse node in the DTS requests PCLK_EFUSE1024NS.
To allow us to add a efuse-driver (and more importantly, to allow
probes of such a driver to succeed), we need need to accept requests
for PCLK_EFUSE1024NS and return a non-error result.

As PCLK_EFUSE1024NS is enabled by default (i.e. after reset), we don't
implement any logic to manage this clock gate and simply assume that
the reset-default has not been changed.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Tested-by: Klaus Goger <klaus.goger@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Kever Yang
a83444ee34 rockchip: add defconfig for firefly-rk3399
The file is from evb-rk3399_defconfig with changes:
- use rk3399-firefly dtb
- re-order by make savedefconfig

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Kever Yang
5540e25aeb dm: sandbox: pwm: add test for pwm_set_invert()
Add test case for new interface set_invert().

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
Fix typo in subject and build error in sandbox_pwm_set_invert():
Signed-off-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Kever Yang
1df7ee573e doc: dtbinding: add pwm binding file
This is a copy from kernel.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Kever Yang
874ee59acc rockchip: pwm: implement pwm_set_invert()
Rockchip pwm need to init polarity, implement pwm_set_invert()
to do it.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Kever Yang
0b60111aa6 power: regulator: pwm: support pwm polarity setting
The latest kernel PWM drivers enable the polarity settings. When system
run from U-Boot to kerenl, if there are differences in polarity set or
duty cycle, the PMW will re-init:
  close -> set polarity and duty cycle -> enable the PWM.
The power supply controled by pwm regulator may have voltage shaking,
which lead to the system not stable.

Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Kever Yang
a66726838e rockchip: dts: add rk3399-firefly dts
Firefly-rk3399 is a bord from T-Firefly, you can find detail about
it here:
http://en.t-firefly.com/en/firenow/Firefly_RK3399/

This patch add basic node for the board and make it able to bring
up.

Peripheral/interfaces on board:
- usb hub which connect to ehci controller;
- UART2 debug
- eMMC
- PCIe
- USB 3.0 HOST, type-C port
- sdio, sd-card
- HDMI
- Ethernet
- OPTICAL
- WiFi/BT
- MIPI CSI/DSI
- IR
- EDP/DP

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Kever Yang
dde2223372 rockchip: dts: rk3399: sync with kernel dts
The kernel dts has update a lot since the first time we commit rk3399.dtsi,
sync with kernel for further development.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Simon Glass
439c947f32 dtoc: Handle nodes with phandles that depend on the same
At present dtoc assumes that nodes which are phandles do not themselves
reference other phandle nodes. Unfortunately this is not necessarilly
true. As a result we can currently output C code which does not compile
because a node declaration can be referenced before it is declared.

Adjust the code to explicitly output all phandle nodes needed by node
before the node itself is output.

This fixes building with the latest rk3399-firefly.dts from Linux, which
has reordered the nodes.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Kever Yang <kever.yang@rock-chips.com>
2017-05-10 13:37:21 -06:00
Simon Glass
49eec8c7f1 dtoc: Move the output code into its own function
The code to generate the tables is quite long. Move the node-output code
into its own function.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Kever Yang <kever.yang@rock-chips.com>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
ff71f9ac33 rockchip: mmc: handle deprecation of 'clock-freq-min-max'
The 'clock-freq-min-max' property was deprecated in the upstream
(i.e. Linux) DTS bindings in favor of the 'max-frequency' property.

With the latest RK3399 DTSI does no longer include the deprecated
property and the rockchip_dw_mmc driver requiring it to be present,
the driver doesn't bind to the node in the RK3399 DTSI any longer
(thus breaking access to the SD card on the RK3399-Q7 board).

To fix this, we implement a similar logic as in the Linux driver: if
the deprecated property is present, we issue a warning (if DEBUG is
enabled); if it is missing, we require 'max-frequency' to be set and
use it to create a min/max value-pair.

See b023030f10
for the deprecation/matching change in Linux.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
998c61ae60 rockchip: clk: rk3399: adapt MMC clk configuration to the updated RK3399 DTS
The clocking of the designware MMC controller in the upstream
(i.e. Linux) RK3399 has changed/does not match what the current DTS in
U-Boot uses: the first clock entry now is HCLK_SDMMC instead of
SCLK_SDMMC.

With the simple clock driver used for the RK3399, this needs a change
in the selector understood by the various case statements in the driver
to ensure that the driver still loads successfully.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Kever Yang
fa1392a236 rockchip: reserve memory for rk3399 ATF data
There are 3 regions used by rk3399 ATF:
- bl31 code, located at 0x10000;
- cortex-m0 code and data, located at 0xff8c0000;
- bl31 data, located at 0xff8c1000 ~ 0xff8c4000;

SPL_TEXT_BASE starts from 0xff8c2000, we need to reserve memory
for ATF data, or else there will be memory corrupt after SPL
loads the ATF image.

More detail about cortex-M0 code in ATF:
https://github.com/ARM-software/arm-trusted-firmware/commit/
8382e17c4c6bffd15119dfce1ee4372e3c1a7890

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Kever Yang
602778d3c7 rockchip: pinctrl: rk3399: add gmac io strength support
GMAC controller need to init the tx io driver strength to 13mA,
just like the description in dts pinctrl node, or else the controller
may only work in 100MHz Mode, and fail to work at 1000MHz mode.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com <mailto:philipp.tomsich@theobroma-systems.com>>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Kever Yang
fd9884e292 rockchip: dts: evb-rk3399: add gmac support
Enable gmac for evb-rk3399.

Change-Id: I85e35667e08e22e38577e63eb0e65731fc9c69b6
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
2017-05-10 13:37:21 -06:00
Kever Yang
76e1693b9b rockchip: rk3399: use actual dram size
Since our sdram driver is ready, we can use the actual size
instead of hard code.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Eddie Cai
7474bbe857 rockchip: enable debug uart
enable debug uart for rk3288 and print something to let people know
where we are

Signed-off-by: Eddie Cai <eddie.cai.linux@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Kever Yang
26b1edf4ce rockchip: dts: evb-rk3399: correct pwm3 polarity
The pwm3 on evb-rk3399 is used for pwm regulator, need to invert
the polarity to make it work correctly.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
572045b6e7 rockchip: dts: rk3399-puma: Add DDR3-1600 timings and use for Puma
With the validation done for DDR3-1600 (i.e. 800 MHz bus clock), we
add the timings (rk3399-sdram-ddr3-1600.dtsi) and change rk3399-puma.dts
to use these by default.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
Drop blank line at end of file:
Signed-off-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
c5f99c654e rockchip: dts: Clean up graffiti in rk3399-sdram-ddr3-1333.dtsi
The DDR3-1333 timings for the RK3399-Q7 (Puma) has some unintended
left-over comments in them. This change cleans the file up.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
253c60a557 rockchip: mkimage: remove placeholder functions from rkimage
The imagetool framework checks whether function pointer for the verify,
print and extract actions are available and will will handle their
absence appropriately.

This change removes the unnecessary functions and uses the driver
structure to convey available functionality to imagetool.  This is in
fact better than having verify just return 0 (which previously broke
dumpimage, as dumpimage assumed that we had handled the image and did
not continue to probe further).

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
24aae93f97 rockchip: mkimage: play nice with dumpimage
Dumpimage (it invoked with "-T rkspi" or "-T rksd") would not work due
to check_params failing. These changes ensure that we can both be called
with an empty imagename.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
a1a2dfb870 rockchip: mkimage: clarify header0 initialisation
This change set adds documentation to the header0 initialisation and
improves readability for the calculations of various offsets/lengths.

As the U-Boot SPL stage doesn't use any payload beyond what is covered
by init_size, we no longer add RK_MAX_BOOT_SIZE to init_boot_size.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
c25b8c3af1 rockchip: mkimage: rksd: pad SD/MMC images to a full blocksize
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
ea3729e23b rockchip: mkimage: Update comments for header size
The calculation of the variable header size in rkcommon_vrec_header
had been update twice in the earlier series (introducing boot0-style
images to deal with the alignment of the first instruction in 64bit
binaries). Unfortunately, I didn't update the comment twice (so it
remained out-of-date).

This change brings the comment back in-sync with what the code is
doing.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
366aad4d97 rockchip: mkimage: rewrite padding calculation for SD/MMC and SPI images
In (first) breaking and (then) fixing the rkspi tool, I realised that
the calculation of the required padding (for the header-size and the
2K-in-every-4K SPI layout) was not as self-explainatory as it could
have been.  This change rewrites the code (using new, common functions
in rkcommon.c) and adds verbose in-line comments to ensure that we
won't fall into the same pit in the future...

Tested on the RK3399 (with has a boot0-style payload) with SD/MMC and SPI.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
798c93faf3 rockchip: mkimage: rkspi: include the header sector in the SPI size calculation
Our earlier change broke the generation of SPI images, by excluding the
2K used for header0 from the size-calculation.

This commit makes sure that these are included before calculating the
required total size (including the padding from the 2K-from-every-4K
conversion).

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
3e75c07ddb rockchip: spl: rk3399: spi: enable SPL_SPI_LOAD if SPI is enabled for SPL
To include the ability to load from an SPI flash in SPL, it's not
sufficient to define SPL_SPI_SUPPORT and SPL_SPI_FLASH_SUPPORT via
Kconfig... so we conditionally define SPL_SPI_LOAD if SPI support
is already enabled for SPL via Kconfig.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Jakob Unterwurzacher
cdeb4d780a rockchip: spi: enable support for the rk_spi driver for the RK3399
The existing Rockchip SPI (rk_spi.c) driver also matches the hardware
block found in the RK3399.  This has been confirmed both with SPI NOR
flashes and general SPI transfers on the RK3399-Q7 for SPI1 and SPI5.

This change adds the 'rockchip,rk3399-spi' string to its compatible
list to allow reuse of the existing driver.

X-AffectedPlatforms: RK3399-Q7
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Tested-by: Jakob Unterwurzacher <jakob.unterwurzacher@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
315e6a38f9 rockchip: pinctrl: rk3399: add support for the SPI5 controller
This commit adds support for the pin-configuration of the SPI5
controller of the RK3399 through the following changes:
 * grf_rk3399.h: adds definition for configuring the SPI5 pins
   		 in the GPIO2C group
 * periph.h: defines PERIPH_ID_SPI3 through PERIPH_ID_SPI5
 * pinctrl_rk3399.c: adds the reverse-mapping from the IRQ# to
   		     PERIPH_ID_SPI5; dispatches PERIPH_ID_SPI3
		     through SPI5 to the appropriate pin-config
		     function; implements the pin-configuration
		     for PERIPH_ID_SPI5 using the GPIO2C group

X-AffectedPlatforms: RK3399-Q7
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Tested-by: Jakob Unterwurzacher <jakob.unterwurzacher@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
9fc354e246 rockchip: spi: rewrite rkspi_set_clk for a more conservative baudrate setting
The baudrate in rkspi was calculated by using an integer division
(which implicitly discarded any fractional result), then rounding to
an even number and finally clamping to 0xfffe using a bitwise AND
operator.  This introduced two issues:
1) for very small baudrates (overflowing the 0xfffe range), the
   bitwise-AND generates rather random-looking (wildly varying)
   actual output bitrates
2) for higher baudrates, the calculation tends to 'err towards a
   higher baudrate' with the actual error increasing as the dividers
   become very small. E.g., with a 99MHz input clock, a request
   for a 20MBit baudrate (99/20 = 4.95), a 24.75 MBit would be use
   (which amounts to a 23.75% error)... for a 34 MBit request this
   would be an actual outbout of 49.5 Mbit (i.e. a 45% error).

This change rewrites the divider selection (i.e. baudrate calculation)
by making sure that
a) for the normal case: the largest representable baudrate below the
   requested rate will be chosen;
b) for the denormal case (i.e. when the divider can no longer be
   represented), the lowest representable baudrate is chosen.

Even though the denormal case (b) may be of little concern in real
world applications (even with a 198MHz input clock, this will only
happen at below approx. 3kHz/3kBit), our board-verification team kept
complaining.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Tested-by: Klaus Goger <klaus.goger@theobroma-systems.com>
2017-05-10 13:37:21 -06:00
Philipp Tomsich
bd37671434 rockchip: spi: rk_spi: dynamically select an module input rate
The original clock/bitrate selection code for the rk_spi driver was a
bit limited, as it always selected a 99MHz input clock rate (which
would allow for a maximum bitrate of 49.5MBit/s), but returned -EINVAL
if a bitrate higher than 48MHz was requested.

To give us better control over the bitrate (i.e. add more operating
points, especially at "higher" bitrate---such as above 9MBit/s), we
try to choose 4x the maximum frequency (clamped to 50MBit) from the
DTS instead of 99MHz... for most use-cases this will yield a frequency
of 198MHz, but is flexible to go beyond this in future configurations.

This also rewrites the check to allow frequencies of up to half the
SPI module rate as bitrates and then clamps to whatever the DTS allows
as a maximum (board-specific) frequency and does away with the -EINVAL
when trying to select a bitrate (for cases that exceeded the hard
limit) and instead consistently clamps to the lower of the hard limit,
the soft limit for the SPI bus (from the DTS) or the soft limit for
the SPI slave device.

This replaces
  "rockchip: spi: rk_spi: select 198MHz input to the SPI module for the RK3399"
  "rockchip: spi: rk_spi: improve clocking code for the RK3399"
from earlier versions of this series.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
2017-05-10 13:37:21 -06:00