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| author | Martin Blumenstingl <martin.blumenstingl@googlemail.com> | 2020-05-12 22:41:47 +0200 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2020-05-28 11:22:14 +0200 |
| commit | e4bf1b0970ef96135c78c7dcf4e14484ce3b9804 (patch) | |
| tree | 4370fb74ace10d9a0afee576c2e894125f1e2c06 /drivers/mmc/host/Kconfig | |
| parent | e5f31378862e5d0e879809bd50a84790ea14a0bc (diff) | |
| download | linux-e4bf1b0970ef96135c78c7dcf4e14484ce3b9804.tar.gz | |
mmc: host: meson-mx-sdhc: new driver for the Amlogic Meson SDHC host
The SDHC MMC host controller on Amlogic SoCs provides an eMMC and MMC
card interface with 1/4/8-bit bus width.
It supports eMMC spec 4.4x/4.5x including HS200 (up to 100MHz clock).
The public S805 datasheet [0] contains a short documentation about the
registers. Unfortunately it does not describe how to use the registers
to make the hardware work. Thus this driver is based on reading (and
understanding) the Amlogic 3.10 GPL kernel code.
Some hardware details are not easy to see. Jianxin Pan was kind enough
to answer my questions:
The hardware has built-in busy timeout support. The maximum timeout is
30 seconds. This is only documented in Amlogic's internal
documentation.
The controller only works with very specific clock configurations. The
details are not part of the public datasheet. In my own words the
supported configurations are:
- 399.812kHz: clkin = 850MHz div = 2126 sd_rx_phase = 63
- 1MHz: clkin = 850MHz div = 850 sd_rx_phase = 55
- 5.986MHz: clkin = 850MHz div = 142 sd_rx_phase = 24
- 25MHz: clkin = 850MHz div = 34 sd_rx_phase = 15
- 47.222MHz: clkin = 850MHz div = 18 sd_rx_phase = 11/15 (SDR50/HS)
- 53.125MHz: clkin = 850MHz div = 16 sd_rx_phase = (tuning)
- 70.833MHz: clkin = 850MHz div = 12 sd_rx_phase = (tuning)
- 85MHz: clkin = 850MHz div = 10 sd_rx_phase = (tuning)
- 94.44MHz: clkin = 850MHz div = 9 sd_rx_phase = (tuning)
- 106.25MHz: clkin = 850MHz div = 8 sd_rx_phase = (tuning)
- 127.5MHz: clkin = 1275MHz div = 10 sd_rx_phase = (tuning)
- 141.667MHz: clkin = 850MHz div = 6 sd_rx_phase = (tuning)
- 159.375MHz: clkin = 1275MHz div = 8 sd_rx_phase = (tuning)
- 212.5MHz: clkin = 1275MHz div = 6 sd_rx_phase = (tuning)
- (sd_tx_phase is always 1, 94.44MHz is not listed in the datasheet
but this is what the 3.10 BSP kernel on Odroid-C1 actually uses)
NOTE: CMD23 support is disabled for now because it results in command
timeouts and thus decreases read performance.
Tested-by: Wei Wang <lnykww@gmail.com>
Tested-by: Xin Yin <yinxin_1989@aliyun.com>
Reviewed-by: Xin Yin <yinxin_1989@aliyun.com>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20200512204147.504087-3-martin.blumenstingl@googlemail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc/host/Kconfig')
| -rw-r--r-- | drivers/mmc/host/Kconfig | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig index 2aee844722d6..ee12451ba708 100644 --- a/drivers/mmc/host/Kconfig +++ b/drivers/mmc/host/Kconfig @@ -405,6 +405,20 @@ config MMC_MESON_GX If you have a controller with this interface, say Y here. +config MMC_MESON_MX_SDHC + tristate "Amlogic Meson SDHC Host Controller support" + depends on (ARM && ARCH_MESON) || COMPILE_TEST + depends on COMMON_CLK + depends on OF + help + This selects support for the SDHC Host Controller on + Amlogic Meson6, Meson8, Meson8b and Meson8m2 SoCs. + The controller supports the SD/SDIO Spec 3.x and eMMC Spec 4.5x + with 1, 4, and 8 bit bus widths. + + If you have a controller with this interface, say Y or M here. + If unsure, say N. + config MMC_MESON_MX_SDIO tristate "Amlogic Meson6/Meson8/Meson8b SD/MMC Host Controller support" depends on ARCH_MESON || COMPILE_TEST |