[PATCH 6/6] rockchip: rk3328: Add support for ROC-RK3328-CC board

[Jagan Teki <jagan@amarulasolutions.com>]

On Mon, Mar 30, 2020 at 11:54 PM Chen-Yu Tsai <wens@kernel.org> wrote:
>
> On Tue, Mar 31, 2020 at 1:44 AM Jagan Teki <jagan@amarulasolutions.com> wrote:
> >
> > Hi Chen-Yu,
> >
> > On Fri, Mar 27, 2020 at 10:12 AM Chen-Yu Tsai <wens@kernel.org> wrote:
> > >
> > > From: Chen-Yu Tsai <wens@csie.org>
> > >
> > > The ROC-RK3328-CC from Firefly and Libre Computer Project is a credit
> > > card size development board based on the Rockchip RK3328 SoC, with:
> > >
> > >   - 1/2/4 GB DDR4 DRAM
> > >   - eMMC connector for optional module
> > >   - micro SD card slot
> > >   - 1 x USB 3.0 host port
> > >   - 2 x USB 2.0 host port
> > >   - 1 x USB 2.0 OTG port
> > >   - HDMI video output
> > >   - TRRS connector with audio and composite video output
> > >   - gigabit Ethernet
> > >   - consumer IR receiver
> > >   - debug UART pins
> > >
> > > The ROC-RK3328-CC has the enable pin of the SD card power switch tied
> > > to GPIO_0_D6. This pin also has the function SDMMC0_PWREN, which is
> > > muxed by default. SDMMC0_PWREN is an active high signal controlled by
> > > the MMC controller, however the switch enable is active low, and
> > > pulled low (enabled) by default to make things work on boot.
> > >
> > > As such, we need to mux away from SDMMC0_PWREN and use GPIO to enable
> > > power to the card. The default GPIO state for the pin is pull-down and
> > > input, which doesn't require extra configuration when paired with the
> > > external pull-down and active low switch.
> > >
> > > Thus we make a custom target for this board and do the muxing in its
> > > spl_board_init() function.
> > >
> > > The device tree file is synced from the Linux kernel next-20200324.
> > >
> > > Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> > > ---
> >
> > [snip]
> >
> > > diff --git a/board/firefly/roc-cc-rk3328/MAINTAINERS b/board/firefly/roc-cc-rk3328/MAINTAINERS
> > > new file mode 100644
> > > index 000000000000..f2318e71ac33
> > > --- /dev/null
> > > +++ b/board/firefly/roc-cc-rk3328/MAINTAINERS
> > > @@ -0,0 +1,7 @@
> > > +ROC-RK3328-CC
> > > +M:      Loic Devulder <ldevulder@suse.com>
> > > +M:     Chen-Yu Tsai <wens@csie.org>
> > > +S:      Maintained
> > > +F:     board/firefly/roc-cc-rk3328/
> > > +F:      configs/roc-rk3328-cc_defconfig
> > > +F:      arch/arm/dts/rk3328-roc-cc-u-boot.dtsi
> > > diff --git a/board/firefly/roc-cc-rk3328/Makefile b/board/firefly/roc-cc-rk3328/Makefile
> > > new file mode 100644
> > > index 000000000000..1550b5f5f16e
> > > --- /dev/null
> > > +++ b/board/firefly/roc-cc-rk3328/Makefile
> > > @@ -0,0 +1 @@
> > > +obj-y  := board.o
> > > diff --git a/board/firefly/roc-cc-rk3328/board.c b/board/firefly/roc-cc-rk3328/board.c
> > > new file mode 100644
> > > index 000000000000..eca58c86b53e
> > > --- /dev/null
> > > +++ b/board/firefly/roc-cc-rk3328/board.c
> > > @@ -0,0 +1,38 @@
> > > +// SPDX-License-Identifier: GPL-2.0+
> > > +/*
> > > + * (C) Copyright 2020 Chen-Yu Tsai <wens@csie.org>
> > > + */
> > > +#include <asm/io.h>
> > > +
> > > +#include <asm/arch-rockchip/grf_rk3328.h>
> > > +#include <asm/arch-rockchip/hardware.h>
> > > +
> > > +#if defined(CONFIG_SPL_BUILD)
> > > +
> > > +#define GRF_BASE       0xFF100000
> > > +
> > > +enum {
> > > +       GPIO_0_D6_GPIO  = 0   << 12,
> > > +       GPIO_0_D6_MASK  = 0x3 << 12
> > > +};
> > > +
> > > +/*
> > > + * The ROC-RK3328-CC has the enable pin of the SD card power switch tied
> > > + * to GPIO_0_D6. This pin also has the function SDMMC0_PWREN, which is
> > > + * muxed by default. SDMMC0_PWREN is an active high signal controlled by
> > > + * the MMC controller, however the switch enable is active low, and
> > > + * pulled low (enabled) by default to make things work on boot.
> > > + *
> > > + * As such, we need to mux away from SDMMC0_PWREN and use GPIO to enable
> > > + * power to the card. The default GPIO state for the pin is pull-down and
> > > + * input, which doesn't require extra configuration when paired with the
> > > + * external pull-down and active low switch.
> > > + */
> > > +void spl_board_init(void)
> > > +{
> > > +       struct rk3328_grf_regs * const grf = (void *)GRF_BASE;
> > > +
> > > +       rk_clrsetreg(&grf->gpio0d_iomux, GPIO_0_D6_MASK, GPIO_0_D6_GPIO);
> > > +}
> >
> > So, this seem toggle the bit 12, 13 of GRF_GPIO0D_IOMUX so-that it
> > operate like a gpio(not like default sdmmc0_pwrenm1), isn't it
> > required for the next stages like U-Boot proper and Linux? these has
> > vcc_sd node where it operates a fixed regulator to active low the same
> > pin.
> >
> > gpio = <&gpio0 RK_PD6 GPIO_ACTIVE_LOW>;
>
> So U-boot proper and Linux both have pinctrl and GPIO and all the stuff
> to deal with this. SPL doesn't have GPIO enabled, and I believe all the
> pinctrl properties are striped out. (BTW, not sure why we're enabling
> pinctrl driver support in SPL if nothing is triggering them.) It seems
> a bit heavy pulling all that stuff in just for one pin mux in SPL. The
> same is also done for the UART pins.

look like it was missed missed enable pinctrl in rk3328-u-boot.dtsi
but usually it should have. I tried of managing all stuff in SPL to
make GPIO-enabled but existing dts never pulled low to make working
like what the above change does.

Here is a sample log: (dts has emmc disabled and vqmmc-supply dropped)

U-Boot TPL 2020.04-rc3-00198-g790eeaefc1-dirty (Mar 31 2020 - 16:19:18)
DDR4, 333MHz
BW=32 Col=10 Bk=4 BG=2 CS0 Row=16 CS1 Row=16 CS=2 Die BW=16 Size=4096MB
Trying to boot from BOOTROM
Returning to boot ROM...

U-Boot SPL 2020.04-rc3-00198-g790eeaefc1-dirty (Mar 31 2020 - 16:19:18 +0530)
Trying to boot from MMC1
device_get_supply_regulator: supply vmmc-supply
rockchip_gpio_direction_output: ff210000, mask 0x40000000, value 0x1
rockchip_gpio_set_value: ff210000, mask 0x40000000, value 0x0
rockchip_gpio_set_value: ff210000 value is 0x0
device_get_supply_regulator: supply vqmmc-supply
mmc at ff500000: No vqmmc supply
rockchip_gpio_set_value: ff210000, mask 0x40000000, value 0x1
rockchip_gpio_set_value: ff210000 value is 0x40000000
rockchip_gpio_set_value: ff210000, mask 0x40000000, value 0x0
rockchip_gpio_set_value: ff210000 value is 0x0
rockchip_gpio_set_value: grf gpio0d value 0x3000
Card did not respond to voltage select!
spl: mmc init failed with error: -95
SPL: failed to boot from all boot devices
### ERROR ### Please RESET the board ###

Jagan.