Re: [PATCH V2 2/2] phy: freescale: add Samsung HDMI PHY

From: Adam Ford
Date: Fri Jan 26 2024 - 21:57:07 EST


On Mon, Jan 8, 2024 at 9:03 AM Alexander Stein
<alexander.stein@xxxxxxxxxxxxxxx> wrote:
>
> Hi Adam,
>
> thanks for pushing this forward.
>
> Am Samstag, 6. Januar 2024, 23:19:05 CET schrieb Adam Ford:
> > From: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> >
> > This adds the driver for the Samsung HDMI PHY found on the
> > i.MX8MP SoC.
> >
> > Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> > Signed-off-by: Adam Ford <aford173@xxxxxxxxx>
> > ---
> > V2: Fixed some whitespace found from checkpatch
> > Change error handling when enabling apbclk to use dev_err_probe
> > Rebase on Linux-Next
> >
> > I (Adam) tried to help move this along, so I took Lucas' patch and
> > attempted to apply fixes based on feedback. I don't have
> > all the history, so apologies for that.
> >
> > diff --git a/drivers/phy/freescale/Kconfig b/drivers/phy/freescale/Kconfig
> > index 853958fb2c06..5c2b73042dfc 100644
> > --- a/drivers/phy/freescale/Kconfig
> > +++ b/drivers/phy/freescale/Kconfig
> > @@ -35,6 +35,12 @@ config PHY_FSL_IMX8M_PCIE
> > Enable this to add support for the PCIE PHY as found on
> > i.MX8M family of SOCs.
> >
> > +config PHY_FSL_SAMSUNG_HDMI_PHY
> > + tristate "Samsung HDMI PHY support"
> > + depends on OF && HAS_IOMEM
> > + help
> > + Enable this to add support for the Samsung HDMI PHY in i.MX8MP.
> > +
> > endif
> >
> > config PHY_FSL_LYNX_28G
> > diff --git a/drivers/phy/freescale/Makefile b/drivers/phy/freescale/Makefile
> > index cedb328bc4d2..dbcafdcc8751 100644
> > --- a/drivers/phy/freescale/Makefile
> > +++ b/drivers/phy/freescale/Makefile
> > @@ -3,4 +3,5 @@ obj-$(CONFIG_PHY_FSL_IMX8MQ_USB) += phy-fsl-imx8mq-usb.o
> > obj-$(CONFIG_PHY_MIXEL_LVDS_PHY) += phy-fsl-imx8qm-lvds-phy.o
> > obj-$(CONFIG_PHY_MIXEL_MIPI_DPHY) += phy-fsl-imx8-mipi-dphy.o
> > obj-$(CONFIG_PHY_FSL_IMX8M_PCIE) += phy-fsl-imx8m-pcie.o
> > +obj-$(CONFIG_PHY_FSL_SAMSUNG_HDMI_PHY) += phy-fsl-samsung-hdmi.o
> > obj-$(CONFIG_PHY_FSL_LYNX_28G) += phy-fsl-lynx-28g.o
>
> I don't know if there was different feedback already. But I would have added
> the entry sorted alphabetically, thus after CONFIG_PHY_FSL_LYNX_28G. Same goes,
> for Kconfig as well.

The Makefile is easy to rearrange, but Kconfig is already out of
alphabetical order, and PHY_FSL_SAMSUNG_HDMI_PHY is encapsulated in an
if statement, so it cannot go after PHY_FSL_LYNX_28G. It is
alphabetical after PHY_FSL_IMX8M.

>
> > diff --git a/drivers/phy/freescale/phy-fsl-samsung-hdmi.c
> > b/drivers/phy/freescale/phy-fsl-samsung-hdmi.c new file mode 100644
> > index 000000000000..54e93ea898f7
> > --- /dev/null
> > +++ b/drivers/phy/freescale/phy-fsl-samsung-hdmi.c
> > @@ -0,0 +1,1078 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Copyright 2020 NXP
> > + * Copyright 2022 Pengutronix, Lucas Stach <kernel@xxxxxxxxxxxxxx>
> > + */
> > +
> > +#include <linux/clk-provider.h>
> > +#include <linux/clk.h>
> > +#include <linux/delay.h>
> > +#include <linux/io.h>
> > +#include <linux/iopoll.h>
> > +#include <linux/module.h>
> > +#include <linux/of_device.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/pm_runtime.h>
> > +
> > +#define HDMI_TX_CONTROL0 0x200
> > +#define HDMI_TX_CONTROL_PHY_PWRDWN BIT(3)
>
> These defines are unused here.

I can drop these.
>
> > +
> > +#define PHY_REG_33 0x84
> > +#define REG33_MODE_SET_DONE BIT(7)
> > +#define REG33_FIX_DA BIT(1)
> > +
> > +#define PHY_REG_34 0x88
> > +#define REG34_PHY_READY BIT(7)
> > +#define REG34_PLL_LOCK BIT(6)
> > +#define REG34_PHY_CLK_READY BIT(5)
> > +
> > +
> > +#define PHY_PLL_REGS_NUM 48
> > +
> > +struct phy_config {
> > + u32 clk_rate;
> > + u8 regs[PHY_PLL_REGS_NUM];
>
> Shouldn't reg be aligned along clk_rate?

Why so? They appear to just be structures where individual parts are
read/written individually. Looking at another HDMI phy driver, it's
not really any different.

>
> Despite that. Tested on TQMa8MPQL/MBa8MPxL + Full-HD HDMI monitor.
>
> Tested-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
>

Thanks for testing.

adam
> Best regards,
> Alexander
>
<snip>

>
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