> From: Neil Armstrong <[email protected]> > Date: Fri, 6 Nov 2020 11:35:30 +0100 > > On 06/11/2020 11:32, Jaehoon Chung wrote: > > On 11/6/20 6:27 PM, Neil Armstrong wrote: > >> Amlogic SM1 SoCs doesn't handle very well high clocks from the DIV2 input > >> Thus we limit the max freq to 26MHz on SM1 SoCs until we handle higher > >> frequencies via the first input from a composite clock. > >> > >> Here 26MHz corresponds to MMC_HS clock speed. > >> > >> We also add a u-boot only sm1 compatible to distinguish the controller. > > > > Well, it's workaround for using eMMC. > > It's for the next release, to have a temporary fix. > The goal is to not have such workaround.... > > > I didn't check all SM1 SoCs..but odroid-c4 is supported hs200 mode (200MHz) > > on Kernel side. > > It means that bootloader can also support its mode. > > > > I'm checking this problem with odroid-c4 target. If i find how to fix, i > > will share. > > H200 will need a big work including tuning and proper clock management.
I worry a bit that this would make things more fragile. I have some trouble getting HS200 to work properly on the Odroid-N2 in OpenBSD (might be a clock management issue). And the fact that on both the Odroid-N2 and Odroid-C4 the eMMC isn't soldered on means that it has to work reliably on a wider variety of eMMC modules. I believe Linux automatically switches back to a lowe-speed mode if HS200 doesn't work isn't it? Should U-Boot do something similar? > If you manage to got that far, I'll be great ! > > Neil > > > > > Best Regards, > > Jaehoon Chung > > > > > >> > >> Finally a TOFIX is added to precise the clock management should use > >> the clock controller instead of local management with fixed clock rates. > >> > >> Signed-off-by: Neil Armstrong <[email protected]> > >> --- > >> drivers/mmc/meson_gx_mmc.c | 26 +++++++++++++++++++++++--- > >> drivers/mmc/meson_gx_mmc.h | 5 +++++ > >> 2 files changed, 28 insertions(+), 3 deletions(-) > >> > >> diff --git a/drivers/mmc/meson_gx_mmc.c b/drivers/mmc/meson_gx_mmc.c > >> index 9350edf3fa..2c6b6cd15b 100644 > >> --- a/drivers/mmc/meson_gx_mmc.c > >> +++ b/drivers/mmc/meson_gx_mmc.c > >> @@ -17,6 +17,14 @@ > >> #include <linux/log2.h> > >> #include "meson_gx_mmc.h" > >> > >> +bool meson_gx_mmc_is_compatible(struct udevice *dev, > >> + enum meson_gx_mmc_compatible family) > >> +{ > >> + enum meson_gx_mmc_compatible compat = dev_get_driver_data(dev); > >> + > >> + return compat == family; > >> +} > >> + > >> static inline void *get_regbase(const struct mmc *mmc) > >> { > >> struct meson_mmc_platdata *pdata = mmc->priv; > >> @@ -42,6 +50,8 @@ static void meson_mmc_config_clock(struct mmc *mmc) > >> if (!mmc->clock) > >> return; > >> > >> + /* TOFIX This should use the proper clock taken from DT */ > >> + > >> /* 1GHz / CLK_MAX_DIV = 15,9 MHz */ > >> if (mmc->clock > 16000000) { > >> clk = SD_EMMC_CLKSRC_DIV2; > >> @@ -265,7 +275,16 @@ static int meson_mmc_probe(struct udevice *dev) > >> cfg->host_caps = MMC_MODE_8BIT | MMC_MODE_4BIT | > >> MMC_MODE_HS_52MHz | MMC_MODE_HS; > >> cfg->f_min = DIV_ROUND_UP(SD_EMMC_CLKSRC_24M, CLK_MAX_DIV); > >> - cfg->f_max = 100000000; /* 100 MHz */; > >> + /* > >> + * TOFIX SM1 SoCs doesn't handle very well high clocks from the DIV2 > >> input > >> + * Thus we limit the max freq to 26MHz on SM1 SoCs until we handle > >> higher > >> + * frequencies via the first input from a composite clock > >> + * 26MHz corresponds to MMC_HS clock speed > >> + */ > >> + if (meson_gx_mmc_is_compatible(dev, MMC_COMPATIBLE_SM1)) > >> + cfg->f_max = 26000000; /* 26 MHz */ > >> + else > >> + cfg->f_max = 100000000; /* 100 MHz */ > >> cfg->b_max = 511; /* max 512 - 1 blocks */ > >> cfg->name = dev->name; > >> > >> @@ -308,8 +327,9 @@ int meson_mmc_bind(struct udevice *dev) > >> } > >> > >> static const struct udevice_id meson_mmc_match[] = { > >> - { .compatible = "amlogic,meson-gx-mmc" }, > >> - { .compatible = "amlogic,meson-axg-mmc" }, > >> + { .compatible = "amlogic,meson-gx-mmc", .data = MMC_COMPATIBLE_GX }, > >> + { .compatible = "amlogic,meson-axg-mmc", .data = MMC_COMPATIBLE_GX }, > >> + { .compatible = "amlogic,meson-sm1-mmc", .data = MMC_COMPATIBLE_SM1 }, > >> { /* sentinel */ } > >> }; > >> > >> diff --git a/drivers/mmc/meson_gx_mmc.h b/drivers/mmc/meson_gx_mmc.h > >> index b4544b5562..92aec5329f 100644 > >> --- a/drivers/mmc/meson_gx_mmc.h > >> +++ b/drivers/mmc/meson_gx_mmc.h > >> @@ -9,6 +9,11 @@ > >> #include <mmc.h> > >> #include <linux/bitops.h> > >> > >> +enum meson_gx_mmc_compatible { > >> + MMC_COMPATIBLE_GX, > >> + MMC_COMPATIBLE_SM1, > >> +}; > >> + > >> #define SDIO_PORT_A 0 > >> #define SDIO_PORT_B 1 > >> #define SDIO_PORT_C 2 > >> > > > >
