[PATCH v14 0/3] mmc: Add LiteSDCard mmc driver

[Gabriel Somlo <gsomlo@gmail.com>]

Add support for the LiteX SD-Card device, LiteSDCard.

LiteSDCard is a simple SD-Card interface available as part of the LiteX
environment, used with various RISC-V and other FPGA based SoCs.

New in v14:
Documentation/devicetree/bindings/mmc/litex,mmc.yaml:
  - add missing `vmmc-supply = ...` property to example section

>New in v13:
>Documentation/devicetree/bindings/mmc/litex,mmc.yaml:
>  - add `vmmc-supply` requirement
>drivers/mmc/host/Kconfig:
>  - add dependency on REGULATOR, REGULATOR_FIXED_VOLTAGE
>drivers/mmc/host/litex_mmc.c:
>  - use `mmc_regulator_get_supply()`, with fallback to hardcoded 3.3V
>
>>New in v12:
>>drivers/mmc/host/Kconfig:
>>  - add dependency on HAVE_CLK for litex_mmc driver
>>  - (re)add "If unsure, say N" to the litex_mmc driver help message
>>drivers/mmc/host/litex_mmc.c:
>>  - prints message using dev_info() before returning success from probe()
>>
>>>New in v11:
>>>  - picked up r/b from Andy
>>>drivers/mmc/host/litex_mmc.c:
>>>  - defensive coding of litex_mmc_interrupt() return logic
>>>  - remove `dev` member of `struct litex_mmc_host`, only used during probe
>>>
>>>>New in v10:
>>>>drivers/mmc/host/litex_mmc.c:
>>>>  - group `linux/mmc/*` includes by themselves
>>>>  - clean-up of `return` style (multiple locations throughout source)
>>>>  - create `mmc_free_host()` wrapper for use with
>>>>    `devm_add_action_or_reset()`
>>>>  - use GFP_KERNEL with `dmam_alloc_coherent()`
>>>>
>>>>>New in v9:
>>>>>drivers/mmc/host/Kconfig:
>>>>>  - fix OF dependency
>>>>>drivers/mmc/host/litex_mmc.c:
>>>>>  - remove `linux/of.h` include, no longer needed since dropping
>>>>>    `of_match_ptr()`
>>>>>  - add `linux/mod_devicetable.h` include
>>>>>  - use devm_action_or_reset() to devm-ify mmc_alloc_host(), and obviate
>>>>>    the need to call mmc_free_host() explicitly during either probe()
>>>>>    error path or during remove()
>>>>>
>>>>>>New in v8:
>>>>>>commit blurbs:
>>>>>>  - cosmetic editing of descriptions
>>>>>>  - removed `Cc:` lines
>>>>>>drivers/mmc/host/litex_mmc.c:
>>>>>>  - fix file header comment (for real, this time)
>>>>>>  - add explicit `bits.h` include
>>>>>>  - remove `of_match_ptr()` wrapper from around .of_match_table argument
>>>>>>  - fix devm ordering issues: use `devm_request_irq()`, which precludes
>>>>>>    the need to call `free_irq()` on `probe()` error path or from `remove()`
>>>>>>
>>>>>>>New in v7:
>>>>>>>
>>>>>>>drivers/mmc/host/Kconfig:
>>>>>>>  - added module name in LiteSDCard Kconfig entry
>>>>>>>
>>>>>>>drivers/mmc/host/litex_mmc.c:
>>>>>>>  - fixed comment formatting, ordering, and capitalization throughout
>>>>>>>    the entire file
>>>>>>>  - sorted header #include statements
>>>>>>>  - removed redundant parantheses in readx_poll_timeout() condition
>>>>>>>  - explicit handling of readx_poll_timeout() timeout scenarios
>>>>>>>  - dev_err() used in litex_mmc_sdcard_wait_done()
>>>>>>>  - use memcpy_fromio() to grab command response
>>>>>>>  - no need to apply 0xffff mask to a 32-bit value right-shifted by 16
>>>>>>>    (host->resp[3])
>>>>>>>  - use clamp() instead of min(max(...)...)
>>>>>>>  - reworked platform_get_irq_optional() error handling logic
>>>>>>>  - no need to explicitly zero host->irq, kzalloc() does that already
>>>>>>>  - added missing free_irq() in litex_mmc_probe() error path
>>>>>>>  - reordered calls inside litex_mmc_remove() (calling mmc_free_host()
>>>>>>>    before free_irq()
>>>>>>>
>>>>>>>>New in v6:
>>>>>>>>
>>>>>>>>drivers/mmc/host/litex_mmc.c:
>>>>>>>>  - fix handling of deferred probe vs. platform_get_irq_optional()
>>>>>>>>  - don't #ifdef dma_set_mask_and_coherent(), since it automatically
>>>>>>>>    does the right thing on both 32- and 64-bit DMA capable arches
>>>>>>>>  - remove MMC_CAP2_FULL_PWR_CYCLE, add MMC_CAP2_NO_MMC to list of
>>>>>>>>    hardcoded capabilities during litex_mmc_probe()
>>>>>>>>  - hardcode mmc->ocr_avail to the full 2.7-3.6V range allowed by the
>>>>>>>>    SDCard spec (the LiteSDCard device doesn't accept software
>>>>>>>>    configuration)
>>>>>>>>
>>>>>>>>>New in v5:
>>>>>>>>>
>>>>>>>>>MAINTAINERS:
>>>>>>>>>
>>>>>>>>>  - picked up a/b Mateusz
>>>>>>>>>
>>>>>>>>>Doc/dt/bindings/mmc/litex,mmc.yaml:
>>>>>>>>>
>>>>>>>>>  - picked up r/b Rob, Joel
>>>>>>>>>
>>>>>>>>>drivers/mmc/host/litex_mmc.c:
>>>>>>>>>
>>>>>>>>>  - shorten #define constant names (cosmetic, make them less unwieldy)
>>>>>>>>>  - picked up r/b Joel
>>>>>>>>>
>>>>>>>>>>New in v4:
>>>>>>>>>>
>>>>>>>>>>Doc/dt/bindings/mmc/litex,mmc.yaml:
>>>>>>>>>>
>>>>>>>>>>  - fixed `dt_binding_check` errors uncovered by Rob's script
>>>>>>>>>>
>>>>>>>>>>drivers/mmc/host/litex_mmc.c:
>>>>>>>>>>
>>>>>>>>>>  - struct litex_mmc_host fields re-ordered so that `pahole` reports
>>>>>>>>>>    no holes in either 32- or 64-bit builds
>>>>>>>>>>  - litex_mmc_set_bus_width() now encapsulates check for
>>>>>>>>>>    host->is_bus_width_set
>>>>>>>>>>  - litex_mmc_request() - factor out dma data setup into separate
>>>>>>>>>>    helper function: litex_mmc_do_dma()
>>>>>>>>>>
>>>>>>>>>>>New in v3:
>>>>>>>>>>>
>>>>>>>>>>>  MAINTAINERS:
>>>>>>>>>>>
>>>>>>>>>>>  - picked up acked-by Joel
>>>>>>>>>>>  - added listing for liteeth driver
>>>>>>>>>>>  - added Joel as additional co-maintainer (thanks!)
>>>>>>>>>>>
>>>>>>>>>>>  Doc/dt/bindings/mmc/litex,mmc.yaml:
>>>>>>>>>>>
>>>>>>>>>>>  - picked up r/b Geert Uytterhoeven <geert@linux-m68k.org> in DT
>>>>>>>>>>>    bindings document (please let me know if that was premature, and
>>>>>>>>>>>    happy to take further review if needed :)
>>>>>>>>>>>  - add dedicated DT property for source clock frequency
>>>>>>>>>>>
>>>>>>>>>>>  drivers/mmc/host/litex_mmc.c:
>>>>>>>>>>>
>>>>>>>>>>>  - fixed function signature (no line split), and naming (litex_mmc_*)
>>>>>>>>>>>  - more informative MODULE_AUTHOR() entries
>>>>>>>>>>>    - also added matching "Copyright" entries in file header
>>>>>>>>>>>  - fixed description in Kconfig
>>>>>>>>>>>  - fixed DT documentation
>>>>>>>>>>>  - removed magic constants
>>>>>>>>>>>  - removed litex_map_status(), have sdcard_wait_done() return *real*
>>>>>>>>>>>    error codes directly instead.
>>>>>>>>>>>  - streamlined litex_mmc_reponse_len()
>>>>>>>>>>>  - call litex_mmc_set_bus_width() only once, and ensure it returns
>>>>>>>>>>>    correct error code(s)
>>>>>>>>>>>  - use readx_poll_timeout() -- more concise -- instead of
>>>>>>>>>>>    read_poll_timeout()
>>>>>>>>>>>  - use dev_err() in litex_mmc_send_cmd() (instead of pr_err())
>>>>>>>>>>>  - litex_mmc_setclk() will update host->clock before returning
>>>>>>>>>>>  - separate irq initialization into its own function,
>>>>>>>>>>>    litex_mmc_irq_init()
>>>>>>>>>>>  - document rationale for f_min, f_max
>>>>>>>>>>>  - use dmam_alloc_coherent(), which simplifies cleanup significantly
>>>>>>>>>>>  - large `if (data) { ... }` block in litex_mmc_request() left as-is,
>>>>>>>>>>>    there are too many variables shared with the rest of the parent
>>>>>>>>>>>    function body to easily separate (e.g., `len`, `transfer`, `direct`).
>>>>>>>>>>>    If this is indeed a blocker, I can take another shot at refactoring
>>>>>>>>>>>    it in a future revision!
>>>>>>>>>>>  - bump dma_set_mask_and_coherent() to 64-bits on suitable
>>>>>>>>>>>    architectures
>>>>>>>>>>>  - clock source picked up from dedicated DT clock reference property
>>>>>>>>>>>  - remove gpio card-detect logic (needs testing and a dt binding
>>>>>>>>>>>    example before being eligible for upstream inclusion)
>>>>>>>>>>>
>>>>>>>>>>>> New in v2:
>>>>>>>>>>>>   - reword info message in litex_set_clk()
>>>>>>>>>>>>   - streamline code in litex_map_status()
>>>>>>>>>>>>   - fix typos in Kconfig (thanks Randy Dunlap <rdunlap@infradead.org>)
>>>>>>>>>>>>   - improvements suggested by Stafford Horne <shorne@gmail.com>
>>>>>>>>>>>>     - allow COMPILE_TEST in Kconfig
>>>>>>>>>>>>     - use read_poll_timeout() when waiting for cmd/data/DMA
>>>>>>>>>>>>       xfer completion
>>>>>>>>>>>>   - include interrupt.h (thanks kernel test robot <lkp@intel.com>)

Gabriel Somlo (3):
  MAINTAINERS: co-maintain LiteX platform
  dt-bindings: mmc: Add bindings for LiteSDCard
  mmc: Add driver for LiteX's LiteSDCard interface

 .../devicetree/bindings/mmc/litex,mmc.yaml    |  78 +++
 MAINTAINERS                                   |   9 +-
 drivers/mmc/host/Kconfig                      |  13 +
 drivers/mmc/host/Makefile                     |   1 +
 drivers/mmc/host/litex_mmc.c                  | 661 ++++++++++++++++++
 5 files changed, 760 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/mmc/litex,mmc.yaml
 create mode 100644 drivers/mmc/host/litex_mmc.c

-- 
2.31.1