[RFC 1/7] mmc: fsl_esdhc_imx: add OF_PLATDATA support
Simon Glass
sjg at chromium.org
Thu Apr 9 21:50:18 CEST 2020
Hi Walter,
On Thu, 9 Apr 2020 at 13:44, Walter Lozano <walter.lozano at collabora.com> wrote:
>
> Hi Simon,
>
> On 9/4/20 16:36, Simon Glass wrote:
> > Hi Walter,
> >
> > On Thu, 9 Apr 2020 at 13:07, Walter Lozano <walter.lozano at collabora.com> wrote:
> >> Hi Simon,
> >>
> >> On 8/4/20 00:14, Simon Glass wrote:
> >>> Hi Walter,
> >>>
> >>> On Tue, 7 Apr 2020 at 14:05, Walter Lozano <walter.lozano at collabora.com> wrote:
> >>>> Hi Simon,
> >>>>
> >>>> Thank you for taking the time to review this series.
> >>>>
> >>>> On 6/4/20 00:42, Simon Glass wrote:
> >>>>> Hi Walter,
> >>>>>
> >>>>> On Sun, 29 Mar 2020 at 21:32, Walter Lozano<walter.lozano at collabora.com> wrote:
> >>>>>> Signed-off-by: Walter Lozano<walter.lozano at collabora.com>
> >>>>>> ---
> >>>>>> drivers/mmc/fsl_esdhc_imx.c | 46 +++++++++++++++++++++++++++++++++----
> >>>>>> 1 file changed, 42 insertions(+), 4 deletions(-)
> >>>>>>
> >>>>>> diff --git a/drivers/mmc/fsl_esdhc_imx.c b/drivers/mmc/fsl_esdhc_imx.c
> >>>>>> index 4900498e9b..761a4b46e9 100644
> >>>>>> --- a/drivers/mmc/fsl_esdhc_imx.c
> >>>>>> +++ b/drivers/mmc/fsl_esdhc_imx.c
> >>>>>> @@ -29,6 +29,8 @@
> >>>>>> #include <dm.h>
> >>>>>> #include <asm-generic/gpio.h>
> >>>>>> #include <dm/pinctrl.h>
> >>>>>> +#include <dt-structs.h>
> >>>>>> +#include <mapmem.h>
> >>>>>>
> >>>>>> #if !CONFIG_IS_ENABLED(BLK)
> >>>>>> #include "mmc_private.h"
> >>>>>> @@ -98,6 +100,11 @@ struct fsl_esdhc {
> >>>>>> };
> >>>>>>
> >>>>>> struct fsl_esdhc_plat {
> >>>>>> +#if CONFIG_IS_ENABLED(OF_PLATDATA)
> >>>>>> + /* Put this first since driver model will copy the data here */
> >>>>>> + struct dtd_fsl_imx6q_usdhc dtplat;
> >>>>>> +#endif
> >>>>>> +
> >>>>>> struct mmc_config cfg;
> >>>>>> struct mmc mmc;
> >>>>>> };
> >>>>>> @@ -1377,14 +1384,18 @@ static int fsl_esdhc_probe(struct udevice *dev)
> >>>>>> struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
> >>>>>> struct fsl_esdhc_plat *plat = dev_get_platdata(dev);
> >>>>>> struct fsl_esdhc_priv *priv = dev_get_priv(dev);
> >>>>>> +#if !CONFIG_IS_ENABLED(OF_PLATDATA)
> >>>>>> const void *fdt = gd->fdt_blob;
> >>>>>> int node = dev_of_offset(dev);
> >>>>>> + fdt_addr_t addr;
> >>>>>> +#else
> >>>>>> + struct dtd_fsl_imx6q_usdhc *dtplat = &plat->dtplat;
> >>>>>> +#endif
> >>>>>> struct esdhc_soc_data *data =
> >>>>>> (struct esdhc_soc_data *)dev_get_driver_data(dev);
> >>>>>> #if CONFIG_IS_ENABLED(DM_REGULATOR)
> >>>>>> struct udevice *vqmmc_dev;
> >>>>>> #endif
> >>>>>> - fdt_addr_t addr;
> >>>>>> unsigned int val;
> >>>>>> struct mmc *mmc;
> >>>>>> #if !CONFIG_IS_ENABLED(BLK)
> >>>>>> @@ -1392,14 +1403,23 @@ static int fsl_esdhc_probe(struct udevice *dev)
> >>>>>> #endif
> >>>>>> int ret;
> >>>>>>
> >>>>>> +#if CONFIG_IS_ENABLED(OF_PLATDATA)
> >>>>>> + priv->esdhc_regs = map_sysmem(dtplat->reg[0], dtplat->reg[1]);
> >>>>>> + val = plat->dtplat.bus_width;
> >>>>>> + if (val == 8)
> >>>>>> + priv->bus_width = 8;
> >>>>>> + else if (val == 4)
> >>>>>> + priv->bus_width = 4;
> >>>>>> + else
> >>>>>> + priv->bus_width = 1;
> >>>>>> + priv->non_removable = 1;
> >>>>>> +#else
> >>>>>> addr = dev_read_addr(dev);
> >>>>>> if (addr == FDT_ADDR_T_NONE)
> >>>>>> return -EINVAL;
> >>>>>> priv->esdhc_regs = (struct fsl_esdhc *)addr;
> >>>>>> priv->dev = dev;
> >>>>>> priv->mode = -1;
> >>>>>> - if (data)
> >>>>>> - priv->flags = data->flags;
> >>>>>>
> >>>>>> val = dev_read_u32_default(dev, "bus-width", -1);
> >>>>>> if (val == 8)
> >>>>>> @@ -1462,7 +1482,9 @@ static int fsl_esdhc_probe(struct udevice *dev)
> >>>>>> priv->vs18_enable = 1;
> >>>>>> }
> >>>>>> #endif
> >>>>>> -
> >>>>>> +#endif
> >>>>>> + if (data)
> >>>>>> + priv->flags = data->flags;
> >>>>>> /*
> >>>>>> * TODO:
> >>>>>> * Because lack of clk driver, if SDHC clk is not enabled,
> >>>>>> @@ -1513,9 +1535,11 @@ static int fsl_esdhc_probe(struct udevice *dev)
> >>>>>> return ret;
> >>>>>> }
> >>>>>>
> >>>>>> +#if !CONFIG_IS_ENABLED(OF_PLATDATA)
> >>>>> Maybe can use if() for this one?
> >>>> Thank you for the suggestion
> >>>>
> >>>>>> ret = mmc_of_parse(dev, &plat->cfg);
> >>>>>> if (ret)
> >>>>>> return ret;
> >>>>>> +#endif
> >>>>>>
> >>>>>> mmc = &plat->mmc;
> >>>>>> mmc->cfg = &plat->cfg;
> >>>>>> @@ -1648,4 +1672,18 @@ U_BOOT_DRIVER(fsl_esdhc) = {
> >>>>>> .platdata_auto_alloc_size = sizeof(struct fsl_esdhc_plat),
> >>>>>> .priv_auto_alloc_size = sizeof(struct fsl_esdhc_priv),
> >>>>>> };
> >>>>>> +
> >>>>>> +#if CONFIG_IS_ENABLED(OF_PLATDATA)
> >>>>> Don't you already have a U_BOOT_DRIVER declaration?
> >>>>>
> >>>>> You may need to change the name of your existing driver though (see
> >>>>> of-platdata docs).
> >>>>>
> >>>>> So if it is because of that, please add a comment.
> >>>> I have my doubts regarding this issue. As I see, this driver is used by
> >>>> many different DT with different compatible strings, so I'm thinking in
> >>>> trying to find a more generic approach. Would it be useful to have a
> >>>> more elaborated solution searching for the compatible string when
> >>>> matching drivers with device?
> >>> Yes I think so.
> >>>
> >>> Actually searching for a string is not great anyway. I wonder if we
> >>> can use the linker-list idea in the previous email somehow?
> >>
> >> I'm sure I' understand the idea you try to share with me. Sorry, I
> >> understand that one limitation of the current implementation of
> >> OF_PLATDATA is the fact that the U_BOOT_DRIVER name should match the one
> >> used as first entry in DT. As in particular this driver has several
> >> compatible
> >>
> >> { .compatible = "fsl,imx53-esdhc", },
> >> { .compatible = "fsl,imx6ul-usdhc", },
> >> { .compatible = "fsl,imx6sx-usdhc", },
> >> { .compatible = "fsl,imx6sl-usdhc", },
> >> { .compatible = "fsl,imx6q-usdhc", },
> >> { .compatible = "fsl,imx7d-usdhc", .data =
> >> (ulong)&usdhc_imx7d_data,},
> >> { .compatible = "fsl,imx7ulp-usdhc", },
> >> { .compatible = "fsl,imx8qm-usdhc", .data =
> >> (ulong)&usdhc_imx8qm_data,},
> >> { .compatible = "fsl,imx8mm-usdhc", .data =
> >> (ulong)&usdhc_imx8qm_data,},
> >> { .compatible = "fsl,imx8mn-usdhc", .data =
> >> (ulong)&usdhc_imx8qm_data,},
> >> { .compatible = "fsl,imx8mq-usdhc", .data =
> >> (ulong)&usdhc_imx8qm_data,},
> >> { .compatible = "fsl,imxrt-usdhc", },
> >>
> >> and in order to create a general solution, we need to search for the
> >> compatible string instead of matching for driver name.
> >>
> >> Could you please elaborate a bit more your suggestion in order to
> >> understand your approach.
> >>
> >> Thanks in advance.
> > I am wondering if we can use the DM_GET_DRIVER() macro somehow in
> > dt_platdata.c. At present we emit a string, and that string matches
> > the driver name, so we should be able to. That will give a compile
> > error if something is wrong, much better than the current behaviour of
> > not being able to bind the driver at runtime.
> >
> > This is just to improve the current impl, not to do what you are asking here.
> >
> > For what you want, our current approach is to use the first compatible
> > string to find the driver name. Since all compatible strings point to
> > the same driver, perhaps that is good enough? We should at least
> > understand the limitations before going further.
> >
> > The main one I am aware of is that you need to duplicate the
> > U_BOOT_DRIVER()xxx for each compatible string. To fix that we could
> > add:
> >
> > U_BOOT_DRIVER_ALIAS(xxx, new_name)
> >
> > which creates a linker list symbol that points to the original driver,
> > perhaps using ll_entry_get(). That should be easy enough I think. Then
> > whichever symbol you use you will get the same driver since all the
> > symbols point to it.
> >
> > Unfortunately the .data field is not available with of_platdata. That
> > could be added to the dtd_... struct automatically by dtoc, I suspect.
> > However that requires some clever parsing of the C code...
> >
> > As you can tell I would really like to avoid string comparisons and
> > tables of compatible strings in the image itself. It adds overheade.
>
>
> Thanks for taking the time to elaborate your idea, now is clear. I
> totally agree with you, the whole idea behind it to reduce the image
> size, so we need to work to avoid any kind of table of strings.
>
>
> I will investigate you approach and come back to you.
OK sounds good. I should mention that the dtoc tool should be
upstreamed to dtc. I was thinking of sending something very simple to
start.
Regards,
SImon
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