[PATCH v4 0/7] RISC-V: Add MMC support for TH1520 boards

[Drew Fustini]

This series adds support for the MMC controller in the T-Head TH1520
SoC, and it enables the eMMC and microSD slot on both the BeagleV
Ahead and the Sipeed LicheePi 4A.

I tested on top of v6.6 with riscv defconfig. I was able to boot the
Ahead [1] and LPi4a [2] from eMMC. This patch series also exists as a
git branch [3].

Note: I have only tested eMMC and microSD. I have not yet configured
or tested the mmc controller used for SDIO WiFi yet.

References:
[1] https://gist.github.com/pdp7/881342620ec1509685f23a387e2fc8d7
[2] https://gist.github.com/pdp7/97017ad88d83fccac18eba69bff817b7
[3] https://github.com/pdp7/linux/tree/b4/th1520-mmc

Changes in PATCH v4:
- set DWCMSHC_CARD_IS_EMMC when (MMC_CAP2_NO_SD | MMC_CAP2_NO_SDIO)
  as checking MMC_CAP_NONREMOVABLE is not sufficient
- change prefix of phy functions from th1520 to dwcmshc as they are not
  th1520 specific
- remove unneeded check of priv in dwcmshc_phy_1_8v_init()
- remove unneeded check of auto-tuning in th1520_execute_tuning() 
- fix order of new nodes in th1520-beaglev-ahead.dts: move sdhci_clk
  before uart_sclk, move mmc0 and mmc1 before uart0
- fix comment typos pointed out by Adrian
- add trailers that I missed from v2

Changes in PATCH v3:
https://lore.kernel.org/r/20231023-th1520-mmc-v3-0-abc5e7491166@baylibre.com
- always call th1520_sdhci_set_phy() in th1520_set_uhs_signaling()
  and not only when timing is MMC_TIMING_MMC_HS400. This allows the
  microSD slot to work as th1520_phy_3_3v_init() is called from
  th1520_sdhci_set_phy().
- add mmc1 node for mmc controller connected to the microSD slot
- add enable mmc1 and add properties for microSD on the Ahead and LPi4A

Changes in PATCH v2:
https://lore.kernel.org/r/20231017-th1520-mmc-v2-0-4678c8cc4048@baylibre.com
- make use of BIT(), GENMASK(), FIELD_PREP(), FIELD_GET()
- add EXPORT_SYMBOL_GPL(__sdhci_execute_tuning)
- call th1520_phy_1_8v_init() when FLAG_IO_FIXED_1V8 is set
- set DWCMSHC_CARD_IS_EMMC when mmc caps contains MMC_CAP_NONREMOVABLE
- remove manipulation of AT_CTRL_AT_EN from th1520_set_uhs_signaling()
- remove unneccessary cycle of enabling and disabling AT_CTRL_AT_EN in
  th1520_execute_tuning()
- remove th1520_phy_1_8v_init_no_pull()
- remove th1520_phy_3_3v_init_no_pull()
- remove FLAG_PULL_UP_EN from priv->flags
- remove thead,phy-pull-up device tree property

Changes in PACH v1:
https://lore.kernel.org/all/20230921-th1520-mmc-v1-0-49f76c274fb3@baylibre.com/
- ADMA mode now works correctly due to a patch from Jisheng on the list
  ("riscv: dts: thead: set dma-noncoherent to soc bus") and this commit
  from Icenowy that is now merged: 8eb8fe67e2c8 ("riscv: errata: fix
  T-Head dcache.cva encoding").
- Expose __sdhci_execute_tuning from sdhci.c so that it can be called
  from th1520_execute_tuning()
- Refactor the define macros for all the PHY related registers to make
  it easier to understand the bit fields that the code is manipulating
- Replace magic numbers in the PHY register writes with proper defines 
- Replace non_removable in dwcmshc_priv with check of mmc_host.caps
- Drop dt prop "thead,io-fixed-1v8" and instead check for existing
  properties: "mmc-ddr-1_8v", "mmc-hs200-1_8v", or "mmc-hs400-1_8v"
- Rename dt prop from "thead,pull-up" to "thead,phy-pull-up" and
  improve the description in the dt binding
- Replace pull_up_en in dwcmshc_priv with bit field in new flags field
- Create th1520_set_uhs_signaling() and call dwcmshc_set_uhs_signaling()
  from it instead of adding th1520 code to dwcmshc_set_uhs_signaling()
- Return -EIO instead of -1 upon errors in th1520_execute_tuning()

Changes in RFC v2:
https://lore.kernel.org/linux-riscv/20230724-th1520-emmc-v2-0-132ed2e2171e@baylibre.com/
- Expand dwcmshc_priv based on driver in the T-Head 5.10 kernel:
  delay_line, non_removable, pull_up_en, io_fixed_1v8
- New boolean property "thead,pull-up" indicates phy pull-up config
- New boolean property "thead,io-fixed-1v8" indicates that io voltage
  should be set to 1.8V during reset
- Add th1520_phy_1_8v_init() as voltage_switch op
- Add th1520_execute_tuning() as the platform_execute_tuning op
- Added th1520_sdhci_reset() as the .reset op. This function will set
  io voltage to 1.8V after calling the standard sdhci_reset() function.
- Modified dwcmshc_set_uhs_signaling() to enable SDHCI_CTRL_VDD_180 when
  io_fixed_1v8 is true
- Add many defines for register offsets and settings based on the mmc
  support in the T-Head downstream v5.10 kernel

RFC v1 series:
https://lore.kernel.org/r/20230724-th1520-emmc-v1-0-cca1b2533da2@baylibre.com

Signed-off-by: Drew Fustini <dfustini at baylibre.com>
---
Drew Fustini (7):
      dt-bindings: mmc: sdhci-of-dwcmhsc: Add T-Head TH1520 support
      mmc: sdhci: add __sdhci_execute_tuning() to header
      mmc: sdhci-of-dwcmshc: Add support for T-Head TH1520
      riscv: defconfig: Enable mmc and dma drivers for T-Head TH1520
      riscv: dts: thead: Add TH1520 mmc controllers and sdhci clock
      riscv: dts: thead: Enable BeagleV Ahead eMMC and microSD
      riscv: dts: thead: Enable LicheePi 4A eMMC and microSD

 .../bindings/mmc/snps,dwcmshc-sdhci.yaml           |   1 +
 arch/riscv/boot/dts/thead/th1520-beaglev-ahead.dts |  20 ++
 .../boot/dts/thead/th1520-lichee-module-4a.dtsi    |  20 ++
 arch/riscv/boot/dts/thead/th1520.dtsi              |  23 ++
 arch/riscv/configs/defconfig                       |   2 +
 drivers/mmc/host/sdhci-of-dwcmshc.c                | 348 +++++++++++++++++++++
 drivers/mmc/host/sdhci.c                           |   3 +-
 drivers/mmc/host/sdhci.h                           |   1 +
 8 files changed, 417 insertions(+), 1 deletion(-)
---
base-commit: 8cfd133bee055fb537d2338b808079a77de60052
change-id: 20231031-th1520-mmc-b4e846fe6869

Best regards,
-- 
Drew Fustini <dfustini at baylibre.com>