From: Neil Armstrong narmstrong@baylibre.com 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 narmstrong@baylibre.com
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 */@@ -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