* [PATCH v8 0/3] mmc: Add LiteSDCard mmc driver
@ 2022-01-07 23:34 Gabriel Somlo
2022-01-07 23:34 ` [PATCH v8 1/3] MAINTAINERS: co-maintain LiteX platform Gabriel Somlo
` (2 more replies)
0 siblings, 3 replies; 12+ messages in thread
From: Gabriel Somlo @ 2022-01-07 23:34 UTC (permalink / raw)
To: linux-kernel
Cc: robh+dt, devicetree, ulf.hansson, linux-mmc, kgugala, mholenko,
krakoczy, mdudek, paulus, joel, shorne, geert,
david.abdurachmanov, florent, rdunlap, andy.shevchenko
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 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 | 72 ++
MAINTAINERS | 9 +-
drivers/mmc/host/Kconfig | 10 +
drivers/mmc/host/Makefile | 1 +
drivers/mmc/host/litex_mmc.c | 666 ++++++++++++++++++
5 files changed, 756 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
^ permalink raw reply [flat|nested] 12+ messages in thread* [PATCH v8 1/3] MAINTAINERS: co-maintain LiteX platform 2022-01-07 23:34 [PATCH v8 0/3] mmc: Add LiteSDCard mmc driver Gabriel Somlo @ 2022-01-07 23:34 ` Gabriel Somlo 2022-01-07 23:34 ` [PATCH v8 2/3] dt-bindings: mmc: Add bindings for LiteSDCard Gabriel Somlo 2022-01-07 23:34 ` [PATCH v8 3/3] mmc: Add driver for LiteX's LiteSDCard interface Gabriel Somlo 2 siblings, 0 replies; 12+ messages in thread From: Gabriel Somlo @ 2022-01-07 23:34 UTC (permalink / raw) To: linux-kernel Cc: robh+dt, devicetree, ulf.hansson, linux-mmc, kgugala, mholenko, krakoczy, mdudek, paulus, joel, shorne, geert, david.abdurachmanov, florent, rdunlap, andy.shevchenko Add the litex_mmc (LiteSDCard) and LiteETH drivers to the list of files maintained under LiteX. Add Gabriel Somlo and Joel Stanley as maintainers; Joel authored the LiteETH driver, and Gabriel is currently curating the LiteX out-of-tree device drivers as they are tested and prepared for upstream submission, having also co-authored a number of them. Signed-off-by: Gabriel Somlo <gsomlo@gmail.com> Acked-by: Joel Stanley <joel@jms.id.au> Acked-by: Mateusz Holenko <mholenko@antmicro.com> --- MAINTAINERS | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/MAINTAINERS b/MAINTAINERS index dd36acc87ce6..88f105711b85 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11012,12 +11012,17 @@ F: lib/list-test.c LITEX PLATFORM M: Karol Gugala <kgugala@antmicro.com> M: Mateusz Holenko <mholenko@antmicro.com> +M: Gabriel Somlo <gsomlo@gmail.com> +M: Joel Stanley <joel@jms.id.au> S: Maintained F: Documentation/devicetree/bindings/*/litex,*.yaml F: arch/openrisc/boot/dts/or1klitex.dts -F: drivers/soc/litex/litex_soc_ctrl.c -F: drivers/tty/serial/liteuart.c F: include/linux/litex.h +F: drivers/tty/serial/liteuart.c +F: drivers/soc/litex/* +F: drivers/net/ethernet/litex/* +F: drivers/mmc/host/litex_mmc.c +N: litex LIVE PATCHING M: Josh Poimboeuf <jpoimboe@redhat.com> -- 2.31.1 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v8 2/3] dt-bindings: mmc: Add bindings for LiteSDCard 2022-01-07 23:34 [PATCH v8 0/3] mmc: Add LiteSDCard mmc driver Gabriel Somlo 2022-01-07 23:34 ` [PATCH v8 1/3] MAINTAINERS: co-maintain LiteX platform Gabriel Somlo @ 2022-01-07 23:34 ` Gabriel Somlo 2022-01-07 23:34 ` [PATCH v8 3/3] mmc: Add driver for LiteX's LiteSDCard interface Gabriel Somlo 2 siblings, 0 replies; 12+ messages in thread From: Gabriel Somlo @ 2022-01-07 23:34 UTC (permalink / raw) To: linux-kernel Cc: robh+dt, devicetree, ulf.hansson, linux-mmc, kgugala, mholenko, krakoczy, mdudek, paulus, joel, shorne, geert, david.abdurachmanov, florent, rdunlap, andy.shevchenko LiteSDCard is a small footprint, configurable SDCard core for FPGA based SoCs. Signed-off-by: Gabriel Somlo <gsomlo@gmail.com> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Rob Herring <robh@kernel.org> Reviewed-by: Joel Stanley <joel@jms.id.au> --- .../devicetree/bindings/mmc/litex,mmc.yaml | 72 +++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 Documentation/devicetree/bindings/mmc/litex,mmc.yaml diff --git a/Documentation/devicetree/bindings/mmc/litex,mmc.yaml b/Documentation/devicetree/bindings/mmc/litex,mmc.yaml new file mode 100644 index 000000000000..f57cf42b8db7 --- /dev/null +++ b/Documentation/devicetree/bindings/mmc/litex,mmc.yaml @@ -0,0 +1,72 @@ +# SPDX-License-Identifier: GPL-2.0-or-later OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/mmc/litex,mmc.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: LiteX LiteSDCard device + +maintainers: + - Gabriel Somlo <gsomlo@gmail.com> + +description: | + LiteSDCard is a small footprint, configurable SDCard core for FPGA based + system on chips. + + The hardware source is Open Source and can be found on at + https://github.com/enjoy-digital/litesdcard/. + +allOf: + - $ref: mmc-controller.yaml# + +properties: + compatible: + const: litex,mmc + + reg: + items: + - description: PHY registers + - description: CORE registers + - description: DMA Reader buffer + - description: DMA Writer buffer + - description: IRQ registers + minItems: 4 + + reg-names: + items: + - const: phy + - const: core + - const: reader + - const: writer + - const: irq + minItems: 4 + + clocks: + maxItems: 1 + description: + Handle to reference clock. + + interrupts: + maxItems: 1 + +required: + - compatible + - reg + - reg-names + - clocks + +additionalProperties: false + +examples: + - | + mmc: mmc@12005000 { + compatible = "litex,mmc"; + reg = <0x12005000 0x100>, + <0x12003800 0x100>, + <0x12003000 0x100>, + <0x12004800 0x100>, + <0x12004000 0x100>; + reg-names = "phy", "core", "reader", "writer", "irq"; + clocks = <&reference_clk>; + interrupts = <4>; + }; -- 2.31.1 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v8 3/3] mmc: Add driver for LiteX's LiteSDCard interface 2022-01-07 23:34 [PATCH v8 0/3] mmc: Add LiteSDCard mmc driver Gabriel Somlo 2022-01-07 23:34 ` [PATCH v8 1/3] MAINTAINERS: co-maintain LiteX platform Gabriel Somlo 2022-01-07 23:34 ` [PATCH v8 2/3] dt-bindings: mmc: Add bindings for LiteSDCard Gabriel Somlo @ 2022-01-07 23:34 ` Gabriel Somlo [not found] ` <CAHp75VcHnHpX1=ojmFnujqkf55aS1ePiVW4kKydTJQe=dXbwbQ@mail.gmail.com> 2 siblings, 1 reply; 12+ messages in thread From: Gabriel Somlo @ 2022-01-07 23:34 UTC (permalink / raw) To: linux-kernel Cc: robh+dt, devicetree, ulf.hansson, linux-mmc, kgugala, mholenko, krakoczy, mdudek, paulus, joel, shorne, geert, david.abdurachmanov, florent, rdunlap, andy.shevchenko LiteX (https://github.com/enjoy-digital/litex) is a SoC framework that targets FPGAs. LiteSDCard is a small footprint, configurable SDCard core commonly used in LiteX designs. The driver was first written in May 2020 and has been maintained cooperatively by the LiteX community. Thanks to all contributors! Co-developed-by: Kamil Rakoczy <krakoczy@antmicro.com> Signed-off-by: Kamil Rakoczy <krakoczy@antmicro.com> Co-developed-by: Maciej Dudek <mdudek@internships.antmicro.com> Signed-off-by: Maciej Dudek <mdudek@internships.antmicro.com> Co-developed-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Gabriel Somlo <gsomlo@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> --- New in v8: - remove `Cc:` lines from commit blurb 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: >> - 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: >>> - shorter #define constant names (cosmetic, make them less unwieldy) >>> - picked up reviewed-by Joel >>> >>>>New in v4: >>>> - struct litex_mmc_host fields re-ordered so that `pahole` reports >>>> no holes on 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: >>>>> - 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 and dependencies in Kconfig >>>>> - 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 >>>>> - 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) >>>>> - 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! drivers/mmc/host/Kconfig | 10 + drivers/mmc/host/Makefile | 1 + drivers/mmc/host/litex_mmc.c | 666 +++++++++++++++++++++++++++++++++++ 3 files changed, 677 insertions(+) create mode 100644 drivers/mmc/host/litex_mmc.c diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig index 5af8494c31b5..a24561b74f18 100644 --- a/drivers/mmc/host/Kconfig +++ b/drivers/mmc/host/Kconfig @@ -1093,3 +1093,13 @@ config MMC_OWL config MMC_SDHCI_EXTERNAL_DMA bool + +config MMC_LITEX + tristate "LiteX MMC Host Controller support" + depends on OF + depends on PPC_MICROWATT || LITEX || COMPILE_TEST + help + This selects support for the MMC Host Controller found in LiteX SoCs. + + To compile this driver as a module, choose M here: the + module will be called litex_mmc. diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile index ea36d379bd3c..4e4ceb32c4b4 100644 --- a/drivers/mmc/host/Makefile +++ b/drivers/mmc/host/Makefile @@ -101,6 +101,7 @@ obj-$(CONFIG_MMC_CQHCI) += cqhci.o cqhci-y += cqhci-core.o cqhci-$(CONFIG_MMC_CRYPTO) += cqhci-crypto.o obj-$(CONFIG_MMC_HSQ) += mmc_hsq.o +obj-$(CONFIG_MMC_LITEX) += litex_mmc.o ifeq ($(CONFIG_CB710_DEBUG),y) CFLAGS-cb710-mmc += -DDEBUG diff --git a/drivers/mmc/host/litex_mmc.c b/drivers/mmc/host/litex_mmc.c new file mode 100644 index 000000000000..38952f169a27 --- /dev/null +++ b/drivers/mmc/host/litex_mmc.c @@ -0,0 +1,666 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * LiteX LiteSDCard driver + * + * Copyright (C) 2019-2020 Antmicro <contact@antmicro.com> + * Copyright (C) 2019-2020 Kamil Rakoczy <krakoczy@antmicro.com> + * Copyright (C) 2019-2020 Maciej Dudek <mdudek@internships.antmicro.com> + * Copyright (C) 2020 Paul Mackerras <paulus@ozlabs.org> + * Copyright (C) 2020-2021 Gabriel Somlo <gsomlo@gmail.com> + */ + +#include <linux/bits.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/dma-mapping.h> +#include <linux/interrupt.h> +#include <linux/iopoll.h> +#include <linux/litex.h> +#include <linux/module.h> +#include <linux/mmc/host.h> +#include <linux/mmc/mmc.h> +#include <linux/mmc/sd.h> +#include <linux/of.h> +#include <linux/platform_device.h> + +#define LITEX_PHY_CARDDETECT 0x00 +#define LITEX_PHY_CLOCKERDIV 0x04 +#define LITEX_PHY_INITIALIZE 0x08 +#define LITEX_PHY_WRITESTATUS 0x0C +#define LITEX_CORE_CMDARG 0x00 +#define LITEX_CORE_CMDCMD 0x04 +#define LITEX_CORE_CMDSND 0x08 +#define LITEX_CORE_CMDRSP 0x0C +#define LITEX_CORE_CMDEVT 0x1C +#define LITEX_CORE_DATEVT 0x20 +#define LITEX_CORE_BLKLEN 0x24 +#define LITEX_CORE_BLKCNT 0x28 +#define LITEX_BLK2MEM_BASE 0x00 +#define LITEX_BLK2MEM_LEN 0x08 +#define LITEX_BLK2MEM_ENA 0x0C +#define LITEX_BLK2MEM_DONE 0x10 +#define LITEX_BLK2MEM_LOOP 0x14 +#define LITEX_MEM2BLK_BASE 0x00 +#define LITEX_MEM2BLK_LEN 0x08 +#define LITEX_MEM2BLK_ENA 0x0C +#define LITEX_MEM2BLK_DONE 0x10 +#define LITEX_MEM2BLK_LOOP 0x14 +#define LITEX_MEM2BLK 0x18 +#define LITEX_IRQ_STATUS 0x00 +#define LITEX_IRQ_PENDING 0x04 +#define LITEX_IRQ_ENABLE 0x08 + +#define SD_CTL_DATA_XFER_NONE 0 +#define SD_CTL_DATA_XFER_READ 1 +#define SD_CTL_DATA_XFER_WRITE 2 + +#define SD_CTL_RESP_NONE 0 +#define SD_CTL_RESP_SHORT 1 +#define SD_CTL_RESP_LONG 2 +#define SD_CTL_RESP_SHORT_BUSY 3 + +#define SD_BIT_DONE BIT(0) +#define SD_BIT_WR_ERR BIT(1) +#define SD_BIT_TIMEOUT BIT(2) +#define SD_BIT_CRC_ERR BIT(3) + +#define SD_SLEEP_US 5 +#define SD_TIMEOUT_US 20000 + +#define SDIRQ_CARD_DETECT 1 +#define SDIRQ_SD_TO_MEM_DONE 2 +#define SDIRQ_MEM_TO_SD_DONE 4 +#define SDIRQ_CMD_DONE 8 + +#define LITEX_MMC_OCR (MMC_VDD_27_28 | MMC_VDD_28_29 | MMC_VDD_29_30 | \ + MMC_VDD_30_31 | MMC_VDD_31_32 | MMC_VDD_32_33 | \ + MMC_VDD_33_34 | MMC_VDD_34_35 | MMC_VDD_35_36) + +struct litex_mmc_host { + struct mmc_host *mmc; + struct platform_device *dev; + + void __iomem *sdphy; + void __iomem *sdcore; + void __iomem *sdreader; + void __iomem *sdwriter; + void __iomem *sdirq; + + void *buffer; + size_t buf_size; + dma_addr_t dma; + + struct completion cmd_done; + int irq; + + unsigned int ref_clk; + unsigned int sd_clk; + + u32 resp[4]; + u16 rca; + + bool is_bus_width_set; + bool app_cmd; +}; + +static int litex_mmc_sdcard_wait_done(void __iomem *reg, struct device *dev) +{ + u8 evt; + int ret; + + ret = readx_poll_timeout(litex_read8, reg, evt, evt & SD_BIT_DONE, + SD_SLEEP_US, SD_TIMEOUT_US); + if (ret) + return ret; + if (evt == SD_BIT_DONE) + return 0; + if (evt & SD_BIT_WR_ERR) + return -EIO; + if (evt & SD_BIT_TIMEOUT) + return -ETIMEDOUT; + if (evt & SD_BIT_CRC_ERR) + return -EILSEQ; + dev_err(dev, "%s: unknown error (evt=%x)\n", __func__, evt); + return -EINVAL; +} + +static int litex_mmc_send_cmd(struct litex_mmc_host *host, + u8 cmd, u32 arg, u8 response_len, u8 transfer) +{ + struct device *dev = mmc_dev(host->mmc); + void __iomem *reg; + int ret; + u8 evt; + + litex_write32(host->sdcore + LITEX_CORE_CMDARG, arg); + litex_write32(host->sdcore + LITEX_CORE_CMDCMD, + cmd << 8 | transfer << 5 | response_len); + litex_write8(host->sdcore + LITEX_CORE_CMDSND, 1); + + /* + * Wait for an interrupt if we have an interrupt and either there is + * data to be transferred, or if the card can report busy via DAT0. + */ + if (host->irq > 0 && + (transfer != SD_CTL_DATA_XFER_NONE || + response_len == SD_CTL_RESP_SHORT_BUSY)) { + reinit_completion(&host->cmd_done); + litex_write32(host->sdirq + LITEX_IRQ_ENABLE, + SDIRQ_CMD_DONE | SDIRQ_CARD_DETECT); + wait_for_completion(&host->cmd_done); + } + + ret = litex_mmc_sdcard_wait_done(host->sdcore + LITEX_CORE_CMDEVT, dev); + if (ret) { + dev_err(dev, "Command (cmd %d) error, status %d\n", cmd, ret); + return ret; + } + + if (response_len != SD_CTL_RESP_NONE) { + /* + * NOTE: this matches the semantics of litex_read32() + * regardless of underlying arch endianness! + */ + memcpy_fromio(host->resp, + host->sdcore + LITEX_CORE_CMDRSP, 0x10); + } + + if (!host->app_cmd && cmd == SD_SEND_RELATIVE_ADDR) + host->rca = (host->resp[3] >> 16); + + host->app_cmd = (cmd == MMC_APP_CMD); + + if (transfer == SD_CTL_DATA_XFER_NONE) + return ret; /* OK from prior litex_mmc_sdcard_wait_done() */ + + ret = litex_mmc_sdcard_wait_done(host->sdcore + LITEX_CORE_DATEVT, dev); + if (ret) { + dev_err(dev, "Data xfer (cmd %d) error, status %d\n", cmd, ret); + return ret; + } + + /* Wait for completion of (read or write) DMA transfer */ + reg = (transfer == SD_CTL_DATA_XFER_READ) ? + host->sdreader + LITEX_BLK2MEM_DONE : + host->sdwriter + LITEX_MEM2BLK_DONE; + ret = readx_poll_timeout(litex_read8, reg, evt, evt & SD_BIT_DONE, + SD_SLEEP_US, SD_TIMEOUT_US); + if (ret) + dev_err(dev, "DMA timeout (cmd %d)\n", cmd); + + return ret; +} + +static int litex_mmc_send_app_cmd(struct litex_mmc_host *host) +{ + return litex_mmc_send_cmd(host, MMC_APP_CMD, host->rca << 16, + SD_CTL_RESP_SHORT, SD_CTL_DATA_XFER_NONE); +} + +static int litex_mmc_send_set_bus_w_cmd(struct litex_mmc_host *host, u32 width) +{ + return litex_mmc_send_cmd(host, SD_APP_SET_BUS_WIDTH, width, + SD_CTL_RESP_SHORT, SD_CTL_DATA_XFER_NONE); +} + +static int litex_mmc_set_bus_width(struct litex_mmc_host *host) +{ + bool app_cmd_sent; + int ret; + + if (host->is_bus_width_set) + return 0; + + /* Ensure 'app_cmd' precedes 'app_set_bus_width_cmd' */ + app_cmd_sent = host->app_cmd; /* was preceding command app_cmd? */ + if (!app_cmd_sent) { + ret = litex_mmc_send_app_cmd(host); + if (ret) + return ret; + } + + /* LiteSDCard only supports 4-bit bus width */ + ret = litex_mmc_send_set_bus_w_cmd(host, MMC_BUS_WIDTH_4); + if (ret) + return ret; + + /* Re-send 'app_cmd' if necessary */ + if (app_cmd_sent) { + ret = litex_mmc_send_app_cmd(host); + if (ret) + return ret; + } + + host->is_bus_width_set = true; + + return 0; +} + +static int litex_mmc_get_cd(struct mmc_host *mmc) +{ + struct litex_mmc_host *host = mmc_priv(mmc); + int ret; + + if (!mmc_card_is_removable(mmc)) + return 1; + + ret = !litex_read8(host->sdphy + LITEX_PHY_CARDDETECT); + + /* Ensure bus width will be set (again) upon card (re)insertion */ + if (ret == 0) + host->is_bus_width_set = false; + + return ret; +} + +static irqreturn_t litex_mmc_interrupt(int irq, void *arg) +{ + struct mmc_host *mmc = arg; + struct litex_mmc_host *host = mmc_priv(mmc); + u32 pending = litex_read32(host->sdirq + LITEX_IRQ_PENDING); + + /* Check for card change interrupt */ + if (pending & SDIRQ_CARD_DETECT) { + litex_write32(host->sdirq + LITEX_IRQ_PENDING, + SDIRQ_CARD_DETECT); + mmc_detect_change(mmc, msecs_to_jiffies(10)); + } + + /* Check for command completed */ + if (pending & SDIRQ_CMD_DONE) { + /* Disable it so it doesn't keep interrupting */ + litex_write32(host->sdirq + LITEX_IRQ_ENABLE, + SDIRQ_CARD_DETECT); + complete(&host->cmd_done); + } + + return IRQ_HANDLED; +} + +static u32 litex_mmc_response_len(struct mmc_command *cmd) +{ + if (cmd->flags & MMC_RSP_136) + return SD_CTL_RESP_LONG; + if (!(cmd->flags & MMC_RSP_PRESENT)) + return SD_CTL_RESP_NONE; + if (cmd->flags & MMC_RSP_BUSY) + return SD_CTL_RESP_SHORT_BUSY; + return SD_CTL_RESP_SHORT; +} + +static void litex_mmc_do_dma(struct litex_mmc_host *host, struct mmc_data *data, + unsigned int *len, bool *direct, u8 *transfer) +{ + struct device *dev = mmc_dev(host->mmc); + dma_addr_t dma; + int sg_count; + + /* + * Try to DMA directly to/from the data buffer. + * We can do that if the buffer can be mapped for DMA + * in one contiguous chunk. + */ + dma = host->dma; + *len = data->blksz * data->blocks; + sg_count = dma_map_sg(dev, data->sg, data->sg_len, + mmc_get_dma_dir(data)); + if (sg_count == 1) { + dma = sg_dma_address(data->sg); + *len = sg_dma_len(data->sg); + *direct = true; + } else if (*len > host->buf_size) + *len = host->buf_size; + + if (data->flags & MMC_DATA_READ) { + litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0); + litex_write64(host->sdreader + LITEX_BLK2MEM_BASE, dma); + litex_write32(host->sdreader + LITEX_BLK2MEM_LEN, *len); + litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 1); + *transfer = SD_CTL_DATA_XFER_READ; + } else if (data->flags & MMC_DATA_WRITE) { + if (!*direct) + sg_copy_to_buffer(data->sg, data->sg_len, + host->buffer, *len); + litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0); + litex_write64(host->sdwriter + LITEX_MEM2BLK_BASE, dma); + litex_write32(host->sdwriter + LITEX_MEM2BLK_LEN, *len); + litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 1); + *transfer = SD_CTL_DATA_XFER_WRITE; + } else { + dev_warn(dev, "Data present w/o read or write flag.\n"); + /* Continue: set cmd status, mark req done */ + } + + litex_write16(host->sdcore + LITEX_CORE_BLKLEN, data->blksz); + litex_write32(host->sdcore + LITEX_CORE_BLKCNT, data->blocks); +} + +static void litex_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq) +{ + struct litex_mmc_host *host = mmc_priv(mmc); + struct device *dev = mmc_dev(mmc); + struct mmc_command *cmd = mrq->cmd; + struct mmc_command *sbc = mrq->sbc; + struct mmc_data *data = mrq->data; + struct mmc_command *stop = mrq->stop; + unsigned int retries = cmd->retries; + unsigned int len = 0; + bool direct = false; + u32 response_len = litex_mmc_response_len(cmd); + u8 transfer = SD_CTL_DATA_XFER_NONE; + + /* First check that the card is still there */ + if (!litex_mmc_get_cd(mmc)) { + cmd->error = -ENOMEDIUM; + mmc_request_done(mmc, mrq); + return; + } + + /* Send set-block-count command if needed */ + if (sbc) { + sbc->error = litex_mmc_send_cmd(host, sbc->opcode, sbc->arg, + litex_mmc_response_len(sbc), + SD_CTL_DATA_XFER_NONE); + if (sbc->error) { + host->is_bus_width_set = false; + mmc_request_done(mmc, mrq); + return; + } + } + + if (data) { + /* + * LiteSDCard only supports 4-bit bus width; therefore, we MUST + * inject a SET_BUS_WIDTH (acmd6) before the very first data + * transfer, earlier than when the mmc subsystem would normally + * get around to it! + */ + cmd->error = litex_mmc_set_bus_width(host); + if (cmd->error) { + dev_err(dev, "Can't set bus width!\n"); + mmc_request_done(mmc, mrq); + return; + } + + litex_mmc_do_dma(host, data, &len, &direct, &transfer); + } + + do { + cmd->error = litex_mmc_send_cmd(host, cmd->opcode, cmd->arg, + response_len, transfer); + } while (cmd->error && retries-- > 0); + + if (cmd->error) { + /* Card may be gone; don't assume bus width is still set */ + host->is_bus_width_set = false; + } + + if (response_len == SD_CTL_RESP_SHORT) { + /* Pull short response fields from appropriate host registers */ + cmd->resp[0] = host->resp[3]; + cmd->resp[1] = host->resp[2] & 0xFF; + } else if (response_len == SD_CTL_RESP_LONG) { + cmd->resp[0] = host->resp[0]; + cmd->resp[1] = host->resp[1]; + cmd->resp[2] = host->resp[2]; + cmd->resp[3] = host->resp[3]; + } + + /* Send stop-transmission command if required */ + if (stop && (cmd->error || !sbc)) { + stop->error = litex_mmc_send_cmd(host, stop->opcode, stop->arg, + litex_mmc_response_len(stop), + SD_CTL_DATA_XFER_NONE); + if (stop->error) + host->is_bus_width_set = false; + } + + if (data) { + dma_unmap_sg(dev, data->sg, data->sg_len, + mmc_get_dma_dir(data)); + } + + if (!cmd->error && transfer != SD_CTL_DATA_XFER_NONE) { + data->bytes_xfered = min(len, mmc->max_req_size); + if (transfer == SD_CTL_DATA_XFER_READ && !direct) { + sg_copy_from_buffer(data->sg, sg_nents(data->sg), + host->buffer, data->bytes_xfered); + } + } + + mmc_request_done(mmc, mrq); +} + +static void litex_mmc_setclk(struct litex_mmc_host *host, unsigned int freq) +{ + struct device *dev = mmc_dev(host->mmc); + u32 div; + + div = freq ? host->ref_clk / freq : 256U; + div = roundup_pow_of_two(div); + div = clamp(div, 2U, 256U); + dev_dbg(dev, "sd_clk_freq=%d: set to %d via div=%d\n", + freq, host->ref_clk / div, div); + litex_write16(host->sdphy + LITEX_PHY_CLOCKERDIV, div); + host->sd_clk = freq; +} + +static void litex_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) +{ + struct litex_mmc_host *host = mmc_priv(mmc); + + /* + * NOTE: Ignore any ios->bus_width updates; they occur right after + * the mmc core sends its own acmd6 bus-width change notification, + * which is redundant since we snoop on the command flow and inject + * an early acmd6 before the first data transfer command is sent! + */ + + /* Update sd_clk */ + if (ios->clock != host->sd_clk) + litex_mmc_setclk(host, ios->clock); +} + +static const struct mmc_host_ops litex_mmc_ops = { + .get_cd = litex_mmc_get_cd, + .request = litex_mmc_request, + .set_ios = litex_mmc_set_ios, +}; + +static int litex_mmc_irq_init(struct litex_mmc_host *host) +{ + struct device *dev = mmc_dev(host->mmc); + int ret; + + ret = platform_get_irq_optional(host->dev, 0); + if (ret < 0 && ret != -ENXIO) + return ret; + if (ret > 0) + host->irq = ret; + else { + dev_warn(dev, "Failed to get IRQ, using polling\n"); + goto use_polling; + } + + host->sdirq = devm_platform_ioremap_resource_byname(host->dev, "irq"); + if (IS_ERR(host->sdirq)) + return PTR_ERR(host->sdirq); + + ret = devm_request_irq(dev, host->irq, litex_mmc_interrupt, 0, + "litex-mmc", host->mmc); + if (ret < 0) { + dev_warn(dev, "IRQ request error %d, using polling\n", ret); + goto use_polling; + } + + /* Clear & enable card-change interrupts */ + litex_write32(host->sdirq + LITEX_IRQ_PENDING, SDIRQ_CARD_DETECT); + litex_write32(host->sdirq + LITEX_IRQ_ENABLE, SDIRQ_CARD_DETECT); + + return 0; + +use_polling: + host->mmc->caps |= MMC_CAP_NEEDS_POLL; + return 0; +} + +static int litex_mmc_probe(struct platform_device *pdev) +{ + struct litex_mmc_host *host; + struct mmc_host *mmc; + struct clk *clk; + int ret; + + /* + * NOTE: defaults to max_[req,seg]_size=PAGE_SIZE, max_blk_size=512, + * and max_blk_count accordingly set to 8; + * If for some reason we need to modify max_blk_count, we must also + * re-calculate `max_[req,seg]_size = max_blk_size * max_blk_count;` + */ + mmc = mmc_alloc_host(sizeof(struct litex_mmc_host), &pdev->dev); + if (!mmc) + return -ENOMEM; + + host = mmc_priv(mmc); + host->mmc = mmc; + host->dev = pdev; + + /* Initialize clock source */ + clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(clk)) { + ret = dev_err_probe(&pdev->dev, + PTR_ERR(clk), "can't get clock\n"); + goto err; + } + host->ref_clk = clk_get_rate(clk); + host->sd_clk = 0; + + /* + * LiteSDCard only supports 4-bit bus width; therefore, we MUST inject + * a SET_BUS_WIDTH (acmd6) before the very first data transfer, earlier + * than when the mmc subsystem would normally get around to it! + */ + host->is_bus_width_set = false; + host->app_cmd = false; + + /* LiteSDCard can support 64-bit DMA addressing */ + ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); + if (ret) + goto err; + + host->buf_size = mmc->max_req_size * 2; + host->buffer = dmam_alloc_coherent(&pdev->dev, host->buf_size, + &host->dma, GFP_DMA); + if (host->buffer == NULL) { + ret = -ENOMEM; + goto err; + } + + host->sdphy = devm_platform_ioremap_resource_byname(pdev, "phy"); + if (IS_ERR(host->sdphy)) { + ret = PTR_ERR(host->sdphy); + goto err; + } + + host->sdcore = devm_platform_ioremap_resource_byname(pdev, "core"); + if (IS_ERR(host->sdcore)) { + ret = PTR_ERR(host->sdcore); + goto err; + } + + host->sdreader = devm_platform_ioremap_resource_byname(pdev, "reader"); + if (IS_ERR(host->sdreader)) { + ret = PTR_ERR(host->sdreader); + goto err; + } + + host->sdwriter = devm_platform_ioremap_resource_byname(pdev, "writer"); + if (IS_ERR(host->sdwriter)) { + ret = PTR_ERR(host->sdwriter); + goto err; + } + + /* Ensure DMA bus masters are disabled */ + litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0); + litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0); + + init_completion(&host->cmd_done); + ret = litex_mmc_irq_init(host); + if (ret) + goto err; + + /* Allow full generic 2.7-3.6V range; no software tuning available */ + mmc->ocr_avail = LITEX_MMC_OCR; + + mmc->ops = &litex_mmc_ops; + + /* + * Set default sd_clk frequency range based on empirical observations + * of LiteSDCard gateware behavior on typical SDCard media + */ + mmc->f_min = 12.5e6; + mmc->f_max = 50e6; + + ret = mmc_of_parse(mmc); + if (ret) + goto err; + + /* Force 4-bit bus_width (only width supported by hardware) */ + mmc->caps &= ~MMC_CAP_8_BIT_DATA; + mmc->caps |= MMC_CAP_4_BIT_DATA; + + /* Set default capabilities */ + mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY | + MMC_CAP_DRIVER_TYPE_D | + MMC_CAP_CMD23; + mmc->caps2 |= MMC_CAP2_NO_WRITE_PROTECT | + MMC_CAP2_NO_SDIO | + MMC_CAP2_NO_MMC; + + platform_set_drvdata(pdev, host); + + ret = mmc_add_host(mmc); + if (ret < 0) + goto err; + + return 0; + +err: + mmc_free_host(mmc); + return ret; +} + +static int litex_mmc_remove(struct platform_device *pdev) +{ + struct litex_mmc_host *host = platform_get_drvdata(pdev); + struct mmc_host *mmc = host->mmc; + + mmc_remove_host(mmc); + mmc_free_host(mmc); + + return 0; +} + +static const struct of_device_id litex_match[] = { + { .compatible = "litex,mmc" }, + { } +}; +MODULE_DEVICE_TABLE(of, litex_match); + +static struct platform_driver litex_mmc_driver = { + .probe = litex_mmc_probe, + .remove = litex_mmc_remove, + .driver = { + .name = "litex-mmc", + .of_match_table = litex_match, + }, +}; +module_platform_driver(litex_mmc_driver); + +MODULE_DESCRIPTION("LiteX SDCard driver"); +MODULE_AUTHOR("Antmicro <contact@antmicro.com>"); +MODULE_AUTHOR("Kamil Rakoczy <krakoczy@antmicro.com>"); +MODULE_AUTHOR("Maciej Dudek <mdudek@internships.antmicro.com>"); +MODULE_AUTHOR("Paul Mackerras <paulus@ozlabs.org>"); +MODULE_AUTHOR("Gabriel Somlo <gsomlo@gmail.com>"); +MODULE_LICENSE("GPL v2"); -- 2.31.1 ^ permalink raw reply related [flat|nested] 12+ messages in thread
[parent not found: <CAHp75VcHnHpX1=ojmFnujqkf55aS1ePiVW4kKydTJQe=dXbwbQ@mail.gmail.com>]
* Re: [PATCH v8 3/3] mmc: Add driver for LiteX's LiteSDCard interface [not found] ` <CAHp75VcHnHpX1=ojmFnujqkf55aS1ePiVW4kKydTJQe=dXbwbQ@mail.gmail.com> @ 2022-01-08 1:57 ` Gabriel L. Somlo 2022-01-08 2:31 ` Gabriel L. Somlo 2022-01-08 11:26 ` Andy Shevchenko 0 siblings, 2 replies; 12+ messages in thread From: Gabriel L. Somlo @ 2022-01-08 1:57 UTC (permalink / raw) To: Andy Shevchenko Cc: linux-kernel, robh+dt, devicetree, ulf.hansson, linux-mmc, kgugala, mholenko, krakoczy, mdudek, paulus, joel, shorne, geert, david.abdurachmanov, florent, rdunlap Hi Andy, On Sat, Jan 08, 2022 at 01:54:07AM +0200, Andy Shevchenko wrote: > > > On Saturday, January 8, 2022, Gabriel Somlo <gsomlo@gmail.com> wrote: > > LiteX (https://github.com/enjoy-digital/litex) is a SoC framework > that targets FPGAs. LiteSDCard is a small footprint, configurable > SDCard core commonly used in LiteX designs. > > The driver was first written in May 2020 and has been maintained > cooperatively by the LiteX community. Thanks to all contributors! > > Co-developed-by: Kamil Rakoczy <krakoczy@antmicro.com> > Signed-off-by: Kamil Rakoczy <krakoczy@antmicro.com> > Co-developed-by: Maciej Dudek <mdudek@internships.antmicro.com> > Signed-off-by: Maciej Dudek <mdudek@internships.antmicro.com> > Co-developed-by: Paul Mackerras <paulus@ozlabs.org> > Signed-off-by: Paul Mackerras <paulus@ozlabs.org> > Signed-off-by: Gabriel Somlo <gsomlo@gmail.com> > Reviewed-by: Joel Stanley <joel@jms.id.au> > --- > > New in v8: > - remove `Cc:` lines from commit blurb > 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() > ` > > > > Almost That's encouraging! Thanks for your ongoing time and attention! :) > > >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: > >> - 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: > >>> - shorter #define constant names (cosmetic, make them less unwieldy) > >>> - picked up reviewed-by Joel > >>> > >>>>New in v4: > >>>> - struct litex_mmc_host fields re-ordered so that `pahole` reports > >>>> no holes on 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: > >>>>> - 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 and dependencies in Kconfig > >>>>> - 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 > >>>>> - 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) > >>>>> - 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! > > drivers/mmc/host/Kconfig | 10 + > drivers/mmc/host/Makefile | 1 + > drivers/mmc/host/litex_mmc.c | 666 +++++++++++++++++++++++++++++++++++ > 3 files changed, 677 insertions(+) > create mode 100644 drivers/mmc/host/litex_mmc.c > > diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig > index 5af8494c31b5..a24561b74f18 100644 > --- a/drivers/mmc/host/Kconfig > +++ b/drivers/mmc/host/Kconfig > @@ -1093,3 +1093,13 @@ config MMC_OWL > > config MMC_SDHCI_EXTERNAL_DMA > bool > + > +config MMC_LITEX > + tristate "LiteX MMC Host Controller support" > > > > + depends on OF > > > It looks like functional dependency rather than compilation one. So, there two > options: > - drop it > - unify with the below like > > depends on ((ArchA || ArchB) && OF) || Compile_test OK, went with option b) (unify with line below), will be in v9. > > + depends on PPC_MICROWATT || LITEX || COMPILE_TEST > + help > + This selects support for the MMC Host Controller found in LiteX > SoCs. > + > + To compile this driver as a module, choose M here: the > + module will be called litex_mmc. > diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile > index ea36d379bd3c..4e4ceb32c4b4 100644 > --- a/drivers/mmc/host/Makefile > +++ b/drivers/mmc/host/Makefile > @@ -101,6 +101,7 @@ obj-$(CONFIG_MMC_CQHCI) += cqhci.o > cqhci-y += cqhci-core.o > cqhci-$(CONFIG_MMC_CRYPTO) += cqhci-crypto.o > obj-$(CONFIG_MMC_HSQ) += mmc_hsq.o > +obj-$(CONFIG_MMC_LITEX) += litex_mmc.o > > ifeq ($(CONFIG_CB710_DEBUG),y) > CFLAGS-cb710-mmc += -DDEBUG > diff --git a/drivers/mmc/host/litex_mmc.c b/drivers/mmc/host/litex_mmc.c > new file mode 100644 > index 000000000000..38952f169a27 > --- /dev/null > +++ b/drivers/mmc/host/litex_mmc.c > @@ -0,0 +1,666 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * LiteX LiteSDCard driver > + * > + * Copyright (C) 2019-2020 Antmicro <contact@antmicro.com> > + * Copyright (C) 2019-2020 Kamil Rakoczy <krakoczy@antmicro.com> > + * Copyright (C) 2019-2020 Maciej Dudek <mdudek@internships.antmicro.com> > + * Copyright (C) 2020 Paul Mackerras <paulus@ozlabs.org> > + * Copyright (C) 2020-2021 Gabriel Somlo <gsomlo@gmail.com> > + */ > + > +#include <linux/bits.h> > +#include <linux/clk.h> > +#include <linux/delay.h> > +#include <linux/dma-mapping.h> > +#include <linux/interrupt.h> > +#include <linux/iopoll.h> > +#include <linux/litex.h> > +#include <linux/module.h> > +#include <linux/mmc/host.h> > +#include <linux/mmc/mmc.h> > +#include <linux/mmc/sd.h> > > > > +#include <linux/of.h> > > > Is it used anywhere? Or you meant mod_devicetable.h? Not used since I dropped `of_match_ptr()`, so I'm removing the include in v9 as well -- thanks for catching that! > > +#include <linux/platform_device.h> > + > +#define LITEX_PHY_CARDDETECT 0x00 > +#define LITEX_PHY_CLOCKERDIV 0x04 > +#define LITEX_PHY_INITIALIZE 0x08 > +#define LITEX_PHY_WRITESTATUS 0x0C > +#define LITEX_CORE_CMDARG 0x00 > +#define LITEX_CORE_CMDCMD 0x04 > +#define LITEX_CORE_CMDSND 0x08 > +#define LITEX_CORE_CMDRSP 0x0C > +#define LITEX_CORE_CMDEVT 0x1C > +#define LITEX_CORE_DATEVT 0x20 > +#define LITEX_CORE_BLKLEN 0x24 > +#define LITEX_CORE_BLKCNT 0x28 > +#define LITEX_BLK2MEM_BASE 0x00 > +#define LITEX_BLK2MEM_LEN 0x08 > +#define LITEX_BLK2MEM_ENA 0x0C > +#define LITEX_BLK2MEM_DONE 0x10 > +#define LITEX_BLK2MEM_LOOP 0x14 > +#define LITEX_MEM2BLK_BASE 0x00 > +#define LITEX_MEM2BLK_LEN 0x08 > +#define LITEX_MEM2BLK_ENA 0x0C > +#define LITEX_MEM2BLK_DONE 0x10 > +#define LITEX_MEM2BLK_LOOP 0x14 > +#define LITEX_MEM2BLK 0x18 > +#define LITEX_IRQ_STATUS 0x00 > +#define LITEX_IRQ_PENDING 0x04 > +#define LITEX_IRQ_ENABLE 0x08 > + > +#define SD_CTL_DATA_XFER_NONE 0 > +#define SD_CTL_DATA_XFER_READ 1 > +#define SD_CTL_DATA_XFER_WRITE 2 > + > +#define SD_CTL_RESP_NONE 0 > +#define SD_CTL_RESP_SHORT 1 > +#define SD_CTL_RESP_LONG 2 > +#define SD_CTL_RESP_SHORT_BUSY 3 > + > +#define SD_BIT_DONE BIT(0) > +#define SD_BIT_WR_ERR BIT(1) > +#define SD_BIT_TIMEOUT BIT(2) > +#define SD_BIT_CRC_ERR BIT(3) > + > +#define SD_SLEEP_US 5 > +#define SD_TIMEOUT_US 20000 > + > +#define SDIRQ_CARD_DETECT 1 > +#define SDIRQ_SD_TO_MEM_DONE 2 > +#define SDIRQ_MEM_TO_SD_DONE 4 > +#define SDIRQ_CMD_DONE 8 > + > +#define LITEX_MMC_OCR (MMC_VDD_27_28 | MMC_VDD_28_29 | MMC_VDD_29_30 | \ > + MMC_VDD_30_31 | MMC_VDD_31_32 | MMC_VDD_32_33 | \ > + MMC_VDD_33_34 | MMC_VDD_34_35 | MMC_VDD_35_36) > + > +struct litex_mmc_host { > + struct mmc_host *mmc; > + struct platform_device *dev; > + > + void __iomem *sdphy; > + void __iomem *sdcore; > + void __iomem *sdreader; > + void __iomem *sdwriter; > + void __iomem *sdirq; > + > + void *buffer; > + size_t buf_size; > + dma_addr_t dma; > + > + struct completion cmd_done; > + int irq; > + > + unsigned int ref_clk; > + unsigned int sd_clk; > + > + u32 resp[4]; > + u16 rca; > + > + bool is_bus_width_set; > + bool app_cmd; > +}; > + > +static int litex_mmc_sdcard_wait_done(void __iomem *reg, struct device > *dev) > +{ > + u8 evt; > + int ret; > + > + ret = readx_poll_timeout(litex_read8, reg, evt, evt & SD_BIT_DONE, > + SD_SLEEP_US, SD_TIMEOUT_US); > + if (ret) > + return ret; > + if (evt == SD_BIT_DONE) > + return 0; > + if (evt & SD_BIT_WR_ERR) > + return -EIO; > + if (evt & SD_BIT_TIMEOUT) > + return -ETIMEDOUT; > + if (evt & SD_BIT_CRC_ERR) > + return -EILSEQ; > + dev_err(dev, "%s: unknown error (evt=%x)\n", __func__, evt); > + return -EINVAL; > +} > + > +static int litex_mmc_send_cmd(struct litex_mmc_host *host, > + u8 cmd, u32 arg, u8 response_len, u8 > transfer) > +{ > + struct device *dev = mmc_dev(host->mmc); > + void __iomem *reg; > + int ret; > + u8 evt; > + > + litex_write32(host->sdcore + LITEX_CORE_CMDARG, arg); > + litex_write32(host->sdcore + LITEX_CORE_CMDCMD, > + cmd << 8 | transfer << 5 | response_len); > + litex_write8(host->sdcore + LITEX_CORE_CMDSND, 1); > + > + /* > + * Wait for an interrupt if we have an interrupt and either there > is > + * data to be transferred, or if the card can report busy via DAT0. > + */ > + if (host->irq > 0 && > + (transfer != SD_CTL_DATA_XFER_NONE || > + response_len == SD_CTL_RESP_SHORT_BUSY)) { > + reinit_completion(&host->cmd_done); > + litex_write32(host->sdirq + LITEX_IRQ_ENABLE, > + SDIRQ_CMD_DONE | SDIRQ_CARD_DETECT); > + wait_for_completion(&host->cmd_done); > + } > + > + ret = litex_mmc_sdcard_wait_done(host->sdcore + LITEX_CORE_CMDEVT, > dev); > + if (ret) { > + dev_err(dev, "Command (cmd %d) error, status %d\n", cmd, > ret); > + return ret; > + } > + > + if (response_len != SD_CTL_RESP_NONE) { > + /* > + * NOTE: this matches the semantics of litex_read32() > + * regardless of underlying arch endianness! > + */ > + memcpy_fromio(host->resp, > + host->sdcore + LITEX_CORE_CMDRSP, 0x10); > + } > + > + if (!host->app_cmd && cmd == SD_SEND_RELATIVE_ADDR) > + host->rca = (host->resp[3] >> 16); > + > + host->app_cmd = (cmd == MMC_APP_CMD); > + > + if (transfer == SD_CTL_DATA_XFER_NONE) > + return ret; /* OK from prior litex_mmc_sdcard_wait_done() * > / > + > + ret = litex_mmc_sdcard_wait_done(host->sdcore + LITEX_CORE_DATEVT, > dev); > + if (ret) { > + dev_err(dev, "Data xfer (cmd %d) error, status %d\n", cmd, > ret); > + return ret; > + } > + > + /* Wait for completion of (read or write) DMA transfer */ > + reg = (transfer == SD_CTL_DATA_XFER_READ) ? > + host->sdreader + LITEX_BLK2MEM_DONE : > + host->sdwriter + LITEX_MEM2BLK_DONE; > + ret = readx_poll_timeout(litex_read8, reg, evt, evt & SD_BIT_DONE, > + SD_SLEEP_US, SD_TIMEOUT_US); > + if (ret) > + dev_err(dev, "DMA timeout (cmd %d)\n", cmd); > + > + return ret; > +} > + > +static int litex_mmc_send_app_cmd(struct litex_mmc_host *host) > +{ > + return litex_mmc_send_cmd(host, MMC_APP_CMD, host->rca << 16, > + SD_CTL_RESP_SHORT, > SD_CTL_DATA_XFER_NONE); > +} > + > +static int litex_mmc_send_set_bus_w_cmd(struct litex_mmc_host *host, u32 > width) > +{ > + return litex_mmc_send_cmd(host, SD_APP_SET_BUS_WIDTH, width, > + SD_CTL_RESP_SHORT, > SD_CTL_DATA_XFER_NONE); > +} > + > +static int litex_mmc_set_bus_width(struct litex_mmc_host *host) > +{ > + bool app_cmd_sent; > + int ret; > + > + if (host->is_bus_width_set) > + return 0; > + > + /* Ensure 'app_cmd' precedes 'app_set_bus_width_cmd' */ > + app_cmd_sent = host->app_cmd; /* was preceding command app_cmd? */ > + if (!app_cmd_sent) { > + ret = litex_mmc_send_app_cmd(host); > + if (ret) > + return ret; > + } > + > + /* LiteSDCard only supports 4-bit bus width */ > + ret = litex_mmc_send_set_bus_w_cmd(host, MMC_BUS_WIDTH_4); > + if (ret) > + return ret; > + > + /* Re-send 'app_cmd' if necessary */ > + if (app_cmd_sent) { > + ret = litex_mmc_send_app_cmd(host); > + if (ret) > + return ret; > + } > + > + host->is_bus_width_set = true; > + > + return 0; > +} > + > +static int litex_mmc_get_cd(struct mmc_host *mmc) > +{ > + struct litex_mmc_host *host = mmc_priv(mmc); > + int ret; > + > + if (!mmc_card_is_removable(mmc)) > + return 1; > + > + ret = !litex_read8(host->sdphy + LITEX_PHY_CARDDETECT); > + > + /* Ensure bus width will be set (again) upon card (re)insertion */ > + if (ret == 0) > + host->is_bus_width_set = false; > + > + return ret; > +} > + > +static irqreturn_t litex_mmc_interrupt(int irq, void *arg) > +{ > + struct mmc_host *mmc = arg; > + struct litex_mmc_host *host = mmc_priv(mmc); > + u32 pending = litex_read32(host->sdirq + LITEX_IRQ_PENDING); > + > + /* Check for card change interrupt */ > + if (pending & SDIRQ_CARD_DETECT) { > + litex_write32(host->sdirq + LITEX_IRQ_PENDING, > + SDIRQ_CARD_DETECT); > + mmc_detect_change(mmc, msecs_to_jiffies(10)); > + } > + > + /* Check for command completed */ > + if (pending & SDIRQ_CMD_DONE) { > + /* Disable it so it doesn't keep interrupting */ > + litex_write32(host->sdirq + LITEX_IRQ_ENABLE, > + SDIRQ_CARD_DETECT); > + complete(&host->cmd_done); > + } > + > + return IRQ_HANDLED; > +} > + > +static u32 litex_mmc_response_len(struct mmc_command *cmd) > +{ > + if (cmd->flags & MMC_RSP_136) > + return SD_CTL_RESP_LONG; > + if (!(cmd->flags & MMC_RSP_PRESENT)) > + return SD_CTL_RESP_NONE; > + if (cmd->flags & MMC_RSP_BUSY) > + return SD_CTL_RESP_SHORT_BUSY; > + return SD_CTL_RESP_SHORT; > +} > + > +static void litex_mmc_do_dma(struct litex_mmc_host *host, struct mmc_data > *data, > + unsigned int *len, bool *direct, u8 *transfer) > +{ > + struct device *dev = mmc_dev(host->mmc); > + dma_addr_t dma; > + int sg_count; > + > + /* > + * Try to DMA directly to/from the data buffer. > + * We can do that if the buffer can be mapped for DMA > + * in one contiguous chunk. > + */ > + dma = host->dma; > + *len = data->blksz * data->blocks; > + sg_count = dma_map_sg(dev, data->sg, data->sg_len, > + mmc_get_dma_dir(data)); > + if (sg_count == 1) { > + dma = sg_dma_address(data->sg); > + *len = sg_dma_len(data->sg); > + *direct = true; > + } else if (*len > host->buf_size) > + *len = host->buf_size; > + > + if (data->flags & MMC_DATA_READ) { > + litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0); > + litex_write64(host->sdreader + LITEX_BLK2MEM_BASE, dma); > + litex_write32(host->sdreader + LITEX_BLK2MEM_LEN, *len); > + litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 1); > + *transfer = SD_CTL_DATA_XFER_READ; > + } else if (data->flags & MMC_DATA_WRITE) { > + if (!*direct) > + sg_copy_to_buffer(data->sg, data->sg_len, > + host->buffer, *len); > + litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0); > + litex_write64(host->sdwriter + LITEX_MEM2BLK_BASE, dma); > + litex_write32(host->sdwriter + LITEX_MEM2BLK_LEN, *len); > + litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 1); > + *transfer = SD_CTL_DATA_XFER_WRITE; > + } else { > + dev_warn(dev, "Data present w/o read or write flag.\n"); > + /* Continue: set cmd status, mark req done */ > + } > + > + litex_write16(host->sdcore + LITEX_CORE_BLKLEN, data->blksz); > + litex_write32(host->sdcore + LITEX_CORE_BLKCNT, data->blocks); > +} > + > +static void litex_mmc_request(struct mmc_host *mmc, struct mmc_request > *mrq) > +{ > + struct litex_mmc_host *host = mmc_priv(mmc); > + struct device *dev = mmc_dev(mmc); > + struct mmc_command *cmd = mrq->cmd; > + struct mmc_command *sbc = mrq->sbc; > + struct mmc_data *data = mrq->data; > + struct mmc_command *stop = mrq->stop; > + unsigned int retries = cmd->retries; > + unsigned int len = 0; > + bool direct = false; > + u32 response_len = litex_mmc_response_len(cmd); > + u8 transfer = SD_CTL_DATA_XFER_NONE; > + > + /* First check that the card is still there */ > + if (!litex_mmc_get_cd(mmc)) { > + cmd->error = -ENOMEDIUM; > + mmc_request_done(mmc, mrq); > + return; > + } > + > + /* Send set-block-count command if needed */ > + if (sbc) { > + sbc->error = litex_mmc_send_cmd(host, sbc->opcode, sbc-> > arg, > + litex_mmc_response_len > (sbc), > + SD_CTL_DATA_XFER_NONE); > + if (sbc->error) { > + host->is_bus_width_set = false; > + mmc_request_done(mmc, mrq); > + return; > + } > + } > + > + if (data) { > + /* > + * LiteSDCard only supports 4-bit bus width; therefore, we > MUST > + * inject a SET_BUS_WIDTH (acmd6) before the very first > data > + * transfer, earlier than when the mmc subsystem would > normally > + * get around to it! > + */ > + cmd->error = litex_mmc_set_bus_width(host); > + if (cmd->error) { > + dev_err(dev, "Can't set bus width!\n"); > + mmc_request_done(mmc, mrq); > + return; > + } > + > + litex_mmc_do_dma(host, data, &len, &direct, &transfer); > + } > + > + do { > + cmd->error = litex_mmc_send_cmd(host, cmd->opcode, cmd-> > arg, > + response_len, transfer); > + } while (cmd->error && retries-- > 0); > + > + if (cmd->error) { > + /* Card may be gone; don't assume bus width is still set */ > + host->is_bus_width_set = false; > + } > + > + if (response_len == SD_CTL_RESP_SHORT) { > + /* Pull short response fields from appropriate host > registers */ > + cmd->resp[0] = host->resp[3]; > + cmd->resp[1] = host->resp[2] & 0xFF; > + } else if (response_len == SD_CTL_RESP_LONG) { > + cmd->resp[0] = host->resp[0]; > + cmd->resp[1] = host->resp[1]; > + cmd->resp[2] = host->resp[2]; > + cmd->resp[3] = host->resp[3]; > + } > + > + /* Send stop-transmission command if required */ > + if (stop && (cmd->error || !sbc)) { > + stop->error = litex_mmc_send_cmd(host, stop->opcode, stop-> > arg, > + litex_mmc_response_len > (stop), > + SD_CTL_DATA_XFER_NONE); > + if (stop->error) > + host->is_bus_width_set = false; > + } > + > + if (data) { > + dma_unmap_sg(dev, data->sg, data->sg_len, > + mmc_get_dma_dir(data)); > + } > + > + if (!cmd->error && transfer != SD_CTL_DATA_XFER_NONE) { > + data->bytes_xfered = min(len, mmc->max_req_size); > + if (transfer == SD_CTL_DATA_XFER_READ && !direct) { > + sg_copy_from_buffer(data->sg, sg_nents(data->sg), > + host->buffer, data-> > bytes_xfered); > + } > + } > + > + mmc_request_done(mmc, mrq); > +} > + > +static void litex_mmc_setclk(struct litex_mmc_host *host, unsigned int > freq) > +{ > + struct device *dev = mmc_dev(host->mmc); > + u32 div; > + > + div = freq ? host->ref_clk / freq : 256U; > > > > + div = roundup_pow_of_two(div); > + div = clamp(div, 2U, 256U); > > > Logically seems to me that you may join these two together, because clamped > range is power-of-2 one. `div` needs to be a power-of-2 when written to the LITEX_PHY_CLOCKERDIV register (below). And clamp() will just enforce a min/max range, so if (div = ref_clk / freq) ends up e.g., 5, I need both roundup_pow_of_two() to bump it to 8, and clamp() to enforce that it's between 2 and 256. Unless you mean I should simply write it like: div = clamp(roundup_pow_of_two(div), 2U, 256U); ... as a single line? > + dev_dbg(dev, "sd_clk_freq=%d: set to %d via div=%d\n", > + freq, host->ref_clk / div, div); > + litex_write16(host->sdphy + LITEX_PHY_CLOCKERDIV, div); > + host->sd_clk = freq; > +} > + > +static void litex_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) > +{ > + struct litex_mmc_host *host = mmc_priv(mmc); > + > + /* > + * NOTE: Ignore any ios->bus_width updates; they occur right after > + * the mmc core sends its own acmd6 bus-width change notification, > + * which is redundant since we snoop on the command flow and inject > + * an early acmd6 before the first data transfer command is sent! > + */ > + > + /* Update sd_clk */ > + if (ios->clock != host->sd_clk) > + litex_mmc_setclk(host, ios->clock); > +} > + > +static const struct mmc_host_ops litex_mmc_ops = { > + .get_cd = litex_mmc_get_cd, > + .request = litex_mmc_request, > + .set_ios = litex_mmc_set_ios, > +}; > + > +static int litex_mmc_irq_init(struct litex_mmc_host *host) > +{ > + struct device *dev = mmc_dev(host->mmc); > + int ret; > + > + ret = platform_get_irq_optional(host->dev, 0); > + if (ret < 0 && ret != -ENXIO) > + return ret; > + if (ret > 0) > + host->irq = ret; > + else { > + dev_warn(dev, "Failed to get IRQ, using polling\n"); > + goto use_polling; > + } > + > + host->sdirq = devm_platform_ioremap_resource_byname(host->dev, > "irq"); > + if (IS_ERR(host->sdirq)) > + return PTR_ERR(host->sdirq); > + > + ret = devm_request_irq(dev, host->irq, litex_mmc_interrupt, 0, > + "litex-mmc", host->mmc); > + if (ret < 0) { > + dev_warn(dev, "IRQ request error %d, using polling\n", > ret); > + goto use_polling; > + } > + > + /* Clear & enable card-change interrupts */ > + litex_write32(host->sdirq + LITEX_IRQ_PENDING, SDIRQ_CARD_DETECT); > + litex_write32(host->sdirq + LITEX_IRQ_ENABLE, SDIRQ_CARD_DETECT); > + > + return 0; > + > +use_polling: > + host->mmc->caps |= MMC_CAP_NEEDS_POLL; > + return 0; > +} > + > +static int litex_mmc_probe(struct platform_device *pdev) > +{ > + struct litex_mmc_host *host; > + struct mmc_host *mmc; > + struct clk *clk; > + int ret; > + > + /* > + * NOTE: defaults to max_[req,seg]_size=PAGE_SIZE, max_blk_size= > 512, > + * and max_blk_count accordingly set to 8; > + * If for some reason we need to modify max_blk_count, we must also > + * re-calculate `max_[req,seg]_size = max_blk_size * max_blk_count; > ` > + */ > + mmc = mmc_alloc_host(sizeof(struct litex_mmc_host), &pdev->dev); > > > Should be devm or you may not use devm at all. See hint in one of the previous > messages in v7 discussion. And here I think I'm in trouble... :) None of the examples retrieved via `git log --no-merges --grep devm_add_action_or_reset` are from "drivers/mmc/host/*", and *all* of the mmc drivers there, including the ones that make extensive use of devm_*, use mmc_alloc_host(), and there doesn't appear to be a devm-ified version of mmc_alloc_host() available! How do they all get away with it? I'm really confused now -- any additional clue(s) much appreciated! Thanks, --Gabriel > + if (!mmc) > + return -ENOMEM; > + > + host = mmc_priv(mmc); > + host->mmc = mmc; > + host->dev = pdev; > + > + /* Initialize clock source */ > + clk = devm_clk_get(&pdev->dev, NULL); > + if (IS_ERR(clk)) { > + ret = dev_err_probe(&pdev->dev, > + PTR_ERR(clk), "can't get clock\n"); > + goto err; > + } > + host->ref_clk = clk_get_rate(clk); > + host->sd_clk = 0; > + > + /* > + * LiteSDCard only supports 4-bit bus width; therefore, we MUST > inject > + * a SET_BUS_WIDTH (acmd6) before the very first data transfer, > earlier > + * than when the mmc subsystem would normally get around to it! > + */ > + host->is_bus_width_set = false; > + host->app_cmd = false; > + > + /* LiteSDCard can support 64-bit DMA addressing */ > + ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); > + if (ret) > + goto err; > + > + host->buf_size = mmc->max_req_size * 2; > + host->buffer = dmam_alloc_coherent(&pdev->dev, host->buf_size, > + &host->dma, GFP_DMA); > + if (host->buffer == NULL) { > + ret = -ENOMEM; > + goto err; > + } > + > + host->sdphy = devm_platform_ioremap_resource_byname(pdev, "phy"); > + if (IS_ERR(host->sdphy)) { > + ret = PTR_ERR(host->sdphy); > + goto err; > + } > + > + host->sdcore = devm_platform_ioremap_resource_byname(pdev, "core"); > + if (IS_ERR(host->sdcore)) { > + ret = PTR_ERR(host->sdcore); > + goto err; > + } > + > + host->sdreader = devm_platform_ioremap_resource_byname(pdev, > "reader"); > + if (IS_ERR(host->sdreader)) { > + ret = PTR_ERR(host->sdreader); > + goto err; > + } > + > + host->sdwriter = devm_platform_ioremap_resource_byname(pdev, > "writer"); > + if (IS_ERR(host->sdwriter)) { > + ret = PTR_ERR(host->sdwriter); > + goto err; > + } > + > + /* Ensure DMA bus masters are disabled */ > + litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0); > + litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0); > + > + init_completion(&host->cmd_done); > + ret = litex_mmc_irq_init(host); > + if (ret) > + goto err; > + > + /* Allow full generic 2.7-3.6V range; no software tuning available > */ > + mmc->ocr_avail = LITEX_MMC_OCR; > + > + mmc->ops = &litex_mmc_ops; > + > + /* > + * Set default sd_clk frequency range based on empirical > observations > + * of LiteSDCard gateware behavior on typical SDCard media > + */ > + mmc->f_min = 12.5e6; > + mmc->f_max = 50e6; > + > + ret = mmc_of_parse(mmc); > + if (ret) > + goto err; > + > + /* Force 4-bit bus_width (only width supported by hardware) */ > + mmc->caps &= ~MMC_CAP_8_BIT_DATA; > + mmc->caps |= MMC_CAP_4_BIT_DATA; > + > + /* Set default capabilities */ > + mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY | > + MMC_CAP_DRIVER_TYPE_D | > + MMC_CAP_CMD23; > + mmc->caps2 |= MMC_CAP2_NO_WRITE_PROTECT | > + MMC_CAP2_NO_SDIO | > + MMC_CAP2_NO_MMC; > + > + platform_set_drvdata(pdev, host); > + > + ret = mmc_add_host(mmc); > + if (ret < 0) > + goto err; > + > + return 0; > + > +err: > + mmc_free_host(mmc); > + return ret; > +} > + > +static int litex_mmc_remove(struct platform_device *pdev) > +{ > + struct litex_mmc_host *host = platform_get_drvdata(pdev); > + struct mmc_host *mmc = host->mmc; > + > + mmc_remove_host(mmc); > + mmc_free_host(mmc); > + > + return 0; > +} > + > +static const struct of_device_id litex_match[] = { > + { .compatible = "litex,mmc" }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, litex_match); > + > +static struct platform_driver litex_mmc_driver = { > + .probe = litex_mmc_probe, > + .remove = litex_mmc_remove, > + .driver = { > + .name = "litex-mmc", > + .of_match_table = litex_match, > + }, > +}; > +module_platform_driver(litex_mmc_driver); > + > +MODULE_DESCRIPTION("LiteX SDCard driver"); > +MODULE_AUTHOR("Antmicro <contact@antmicro.com>"); > +MODULE_AUTHOR("Kamil Rakoczy <krakoczy@antmicro.com>"); > +MODULE_AUTHOR("Maciej Dudek <mdudek@internships.antmicro.com>"); > +MODULE_AUTHOR("Paul Mackerras <paulus@ozlabs.org>"); > +MODULE_AUTHOR("Gabriel Somlo <gsomlo@gmail.com>"); > +MODULE_LICENSE("GPL v2"); > -- > 2.31.1 > > > > > -- > With Best Regards, > Andy Shevchenko > > ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v8 3/3] mmc: Add driver for LiteX's LiteSDCard interface 2022-01-08 1:57 ` Gabriel L. Somlo @ 2022-01-08 2:31 ` Gabriel L. Somlo 2022-01-08 11:29 ` Andy Shevchenko 2022-01-08 11:26 ` Andy Shevchenko 1 sibling, 1 reply; 12+ messages in thread From: Gabriel L. Somlo @ 2022-01-08 2:31 UTC (permalink / raw) To: Andy Shevchenko Cc: linux-kernel, robh+dt, devicetree, ulf.hansson, linux-mmc, kgugala, mholenko, krakoczy, mdudek, paulus, joel, shorne, geert, david.abdurachmanov, florent, rdunlap On Fri, Jan 07, 2022 at 08:57:43PM -0500, Gabriel L. Somlo wrote: > Hi Andy, > > On Sat, Jan 08, 2022 at 01:54:07AM +0200, Andy Shevchenko wrote: > > > > > > On Saturday, January 8, 2022, Gabriel Somlo <gsomlo@gmail.com> wrote: > > > > LiteX (https://github.com/enjoy-digital/litex) is a SoC framework > > that targets FPGAs. LiteSDCard is a small footprint, configurable > > SDCard core commonly used in LiteX designs. > > > > The driver was first written in May 2020 and has been maintained > > cooperatively by the LiteX community. Thanks to all contributors! > > > > Co-developed-by: Kamil Rakoczy <krakoczy@antmicro.com> > > Signed-off-by: Kamil Rakoczy <krakoczy@antmicro.com> > > Co-developed-by: Maciej Dudek <mdudek@internships.antmicro.com> > > Signed-off-by: Maciej Dudek <mdudek@internships.antmicro.com> > > Co-developed-by: Paul Mackerras <paulus@ozlabs.org> > > Signed-off-by: Paul Mackerras <paulus@ozlabs.org> > > Signed-off-by: Gabriel Somlo <gsomlo@gmail.com> > > Reviewed-by: Joel Stanley <joel@jms.id.au> > > --- > > > > New in v8: > > - remove `Cc:` lines from commit blurb > > 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() > > ` > > > > > > > > Almost > > That's encouraging! Thanks for your ongoing time and attention! :) > > > > > >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: > > >> - 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: > > >>> - shorter #define constant names (cosmetic, make them less unwieldy) > > >>> - picked up reviewed-by Joel > > >>> > > >>>>New in v4: > > >>>> - struct litex_mmc_host fields re-ordered so that `pahole` reports > > >>>> no holes on 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: > > >>>>> - 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 and dependencies in Kconfig > > >>>>> - 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 > > >>>>> - 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) > > >>>>> - 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! > > > > drivers/mmc/host/Kconfig | 10 + > > drivers/mmc/host/Makefile | 1 + > > drivers/mmc/host/litex_mmc.c | 666 +++++++++++++++++++++++++++++++++++ > > 3 files changed, 677 insertions(+) > > create mode 100644 drivers/mmc/host/litex_mmc.c > > > > diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig > > index 5af8494c31b5..a24561b74f18 100644 > > --- a/drivers/mmc/host/Kconfig > > +++ b/drivers/mmc/host/Kconfig > > @@ -1093,3 +1093,13 @@ config MMC_OWL > > > > config MMC_SDHCI_EXTERNAL_DMA > > bool > > + > > +config MMC_LITEX > > + tristate "LiteX MMC Host Controller support" > > > > > > > > + depends on OF > > > > > > It looks like functional dependency rather than compilation one. So, there two > > options: > > - drop it > > - unify with the below like > > > > depends on ((ArchA || ArchB) && OF) || Compile_test > > OK, went with option b) (unify with line below), will be in v9. > > > > > + depends on PPC_MICROWATT || LITEX || COMPILE_TEST > > + help > > + This selects support for the MMC Host Controller found in LiteX > > SoCs. > > + > > + To compile this driver as a module, choose M here: the > > + module will be called litex_mmc. > > diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile > > index ea36d379bd3c..4e4ceb32c4b4 100644 > > --- a/drivers/mmc/host/Makefile > > +++ b/drivers/mmc/host/Makefile > > @@ -101,6 +101,7 @@ obj-$(CONFIG_MMC_CQHCI) += cqhci.o > > cqhci-y += cqhci-core.o > > cqhci-$(CONFIG_MMC_CRYPTO) += cqhci-crypto.o > > obj-$(CONFIG_MMC_HSQ) += mmc_hsq.o > > +obj-$(CONFIG_MMC_LITEX) += litex_mmc.o > > > > ifeq ($(CONFIG_CB710_DEBUG),y) > > CFLAGS-cb710-mmc += -DDEBUG > > diff --git a/drivers/mmc/host/litex_mmc.c b/drivers/mmc/host/litex_mmc.c > > new file mode 100644 > > index 000000000000..38952f169a27 > > --- /dev/null > > +++ b/drivers/mmc/host/litex_mmc.c > > @@ -0,0 +1,666 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * LiteX LiteSDCard driver > > + * > > + * Copyright (C) 2019-2020 Antmicro <contact@antmicro.com> > > + * Copyright (C) 2019-2020 Kamil Rakoczy <krakoczy@antmicro.com> > > + * Copyright (C) 2019-2020 Maciej Dudek <mdudek@internships.antmicro.com> > > + * Copyright (C) 2020 Paul Mackerras <paulus@ozlabs.org> > > + * Copyright (C) 2020-2021 Gabriel Somlo <gsomlo@gmail.com> > > + */ > > + > > +#include <linux/bits.h> > > +#include <linux/clk.h> > > +#include <linux/delay.h> > > +#include <linux/dma-mapping.h> > > +#include <linux/interrupt.h> > > +#include <linux/iopoll.h> > > +#include <linux/litex.h> > > +#include <linux/module.h> > > +#include <linux/mmc/host.h> > > +#include <linux/mmc/mmc.h> > > +#include <linux/mmc/sd.h> > > > > > > > > +#include <linux/of.h> > > > > > > Is it used anywhere? Or you meant mod_devicetable.h? > > Not used since I dropped `of_match_ptr()`, so I'm removing the > include in v9 as well -- thanks for catching that! > > > > > +#include <linux/platform_device.h> > > + > > +#define LITEX_PHY_CARDDETECT 0x00 > > +#define LITEX_PHY_CLOCKERDIV 0x04 > > +#define LITEX_PHY_INITIALIZE 0x08 > > +#define LITEX_PHY_WRITESTATUS 0x0C > > +#define LITEX_CORE_CMDARG 0x00 > > +#define LITEX_CORE_CMDCMD 0x04 > > +#define LITEX_CORE_CMDSND 0x08 > > +#define LITEX_CORE_CMDRSP 0x0C > > +#define LITEX_CORE_CMDEVT 0x1C > > +#define LITEX_CORE_DATEVT 0x20 > > +#define LITEX_CORE_BLKLEN 0x24 > > +#define LITEX_CORE_BLKCNT 0x28 > > +#define LITEX_BLK2MEM_BASE 0x00 > > +#define LITEX_BLK2MEM_LEN 0x08 > > +#define LITEX_BLK2MEM_ENA 0x0C > > +#define LITEX_BLK2MEM_DONE 0x10 > > +#define LITEX_BLK2MEM_LOOP 0x14 > > +#define LITEX_MEM2BLK_BASE 0x00 > > +#define LITEX_MEM2BLK_LEN 0x08 > > +#define LITEX_MEM2BLK_ENA 0x0C > > +#define LITEX_MEM2BLK_DONE 0x10 > > +#define LITEX_MEM2BLK_LOOP 0x14 > > +#define LITEX_MEM2BLK 0x18 > > +#define LITEX_IRQ_STATUS 0x00 > > +#define LITEX_IRQ_PENDING 0x04 > > +#define LITEX_IRQ_ENABLE 0x08 > > + > > +#define SD_CTL_DATA_XFER_NONE 0 > > +#define SD_CTL_DATA_XFER_READ 1 > > +#define SD_CTL_DATA_XFER_WRITE 2 > > + > > +#define SD_CTL_RESP_NONE 0 > > +#define SD_CTL_RESP_SHORT 1 > > +#define SD_CTL_RESP_LONG 2 > > +#define SD_CTL_RESP_SHORT_BUSY 3 > > + > > +#define SD_BIT_DONE BIT(0) > > +#define SD_BIT_WR_ERR BIT(1) > > +#define SD_BIT_TIMEOUT BIT(2) > > +#define SD_BIT_CRC_ERR BIT(3) > > + > > +#define SD_SLEEP_US 5 > > +#define SD_TIMEOUT_US 20000 > > + > > +#define SDIRQ_CARD_DETECT 1 > > +#define SDIRQ_SD_TO_MEM_DONE 2 > > +#define SDIRQ_MEM_TO_SD_DONE 4 > > +#define SDIRQ_CMD_DONE 8 > > + > > +#define LITEX_MMC_OCR (MMC_VDD_27_28 | MMC_VDD_28_29 | MMC_VDD_29_30 | \ > > + MMC_VDD_30_31 | MMC_VDD_31_32 | MMC_VDD_32_33 | \ > > + MMC_VDD_33_34 | MMC_VDD_34_35 | MMC_VDD_35_36) > > + > > +struct litex_mmc_host { > > + struct mmc_host *mmc; > > + struct platform_device *dev; > > + > > + void __iomem *sdphy; > > + void __iomem *sdcore; > > + void __iomem *sdreader; > > + void __iomem *sdwriter; > > + void __iomem *sdirq; > > + > > + void *buffer; > > + size_t buf_size; > > + dma_addr_t dma; > > + > > + struct completion cmd_done; > > + int irq; > > + > > + unsigned int ref_clk; > > + unsigned int sd_clk; > > + > > + u32 resp[4]; > > + u16 rca; > > + > > + bool is_bus_width_set; > > + bool app_cmd; > > +}; > > + > > +static int litex_mmc_sdcard_wait_done(void __iomem *reg, struct device > > *dev) > > +{ > > + u8 evt; > > + int ret; > > + > > + ret = readx_poll_timeout(litex_read8, reg, evt, evt & SD_BIT_DONE, > > + SD_SLEEP_US, SD_TIMEOUT_US); > > + if (ret) > > + return ret; > > + if (evt == SD_BIT_DONE) > > + return 0; > > + if (evt & SD_BIT_WR_ERR) > > + return -EIO; > > + if (evt & SD_BIT_TIMEOUT) > > + return -ETIMEDOUT; > > + if (evt & SD_BIT_CRC_ERR) > > + return -EILSEQ; > > + dev_err(dev, "%s: unknown error (evt=%x)\n", __func__, evt); > > + return -EINVAL; > > +} > > + > > +static int litex_mmc_send_cmd(struct litex_mmc_host *host, > > + u8 cmd, u32 arg, u8 response_len, u8 > > transfer) > > +{ > > + struct device *dev = mmc_dev(host->mmc); > > + void __iomem *reg; > > + int ret; > > + u8 evt; > > + > > + litex_write32(host->sdcore + LITEX_CORE_CMDARG, arg); > > + litex_write32(host->sdcore + LITEX_CORE_CMDCMD, > > + cmd << 8 | transfer << 5 | response_len); > > + litex_write8(host->sdcore + LITEX_CORE_CMDSND, 1); > > + > > + /* > > + * Wait for an interrupt if we have an interrupt and either there > > is > > + * data to be transferred, or if the card can report busy via DAT0. > > + */ > > + if (host->irq > 0 && > > + (transfer != SD_CTL_DATA_XFER_NONE || > > + response_len == SD_CTL_RESP_SHORT_BUSY)) { > > + reinit_completion(&host->cmd_done); > > + litex_write32(host->sdirq + LITEX_IRQ_ENABLE, > > + SDIRQ_CMD_DONE | SDIRQ_CARD_DETECT); > > + wait_for_completion(&host->cmd_done); > > + } > > + > > + ret = litex_mmc_sdcard_wait_done(host->sdcore + LITEX_CORE_CMDEVT, > > dev); > > + if (ret) { > > + dev_err(dev, "Command (cmd %d) error, status %d\n", cmd, > > ret); > > + return ret; > > + } > > + > > + if (response_len != SD_CTL_RESP_NONE) { > > + /* > > + * NOTE: this matches the semantics of litex_read32() > > + * regardless of underlying arch endianness! > > + */ > > + memcpy_fromio(host->resp, > > + host->sdcore + LITEX_CORE_CMDRSP, 0x10); > > + } > > + > > + if (!host->app_cmd && cmd == SD_SEND_RELATIVE_ADDR) > > + host->rca = (host->resp[3] >> 16); > > + > > + host->app_cmd = (cmd == MMC_APP_CMD); > > + > > + if (transfer == SD_CTL_DATA_XFER_NONE) > > + return ret; /* OK from prior litex_mmc_sdcard_wait_done() * > > / > > + > > + ret = litex_mmc_sdcard_wait_done(host->sdcore + LITEX_CORE_DATEVT, > > dev); > > + if (ret) { > > + dev_err(dev, "Data xfer (cmd %d) error, status %d\n", cmd, > > ret); > > + return ret; > > + } > > + > > + /* Wait for completion of (read or write) DMA transfer */ > > + reg = (transfer == SD_CTL_DATA_XFER_READ) ? > > + host->sdreader + LITEX_BLK2MEM_DONE : > > + host->sdwriter + LITEX_MEM2BLK_DONE; > > + ret = readx_poll_timeout(litex_read8, reg, evt, evt & SD_BIT_DONE, > > + SD_SLEEP_US, SD_TIMEOUT_US); > > + if (ret) > > + dev_err(dev, "DMA timeout (cmd %d)\n", cmd); > > + > > + return ret; > > +} > > + > > +static int litex_mmc_send_app_cmd(struct litex_mmc_host *host) > > +{ > > + return litex_mmc_send_cmd(host, MMC_APP_CMD, host->rca << 16, > > + SD_CTL_RESP_SHORT, > > SD_CTL_DATA_XFER_NONE); > > +} > > + > > +static int litex_mmc_send_set_bus_w_cmd(struct litex_mmc_host *host, u32 > > width) > > +{ > > + return litex_mmc_send_cmd(host, SD_APP_SET_BUS_WIDTH, width, > > + SD_CTL_RESP_SHORT, > > SD_CTL_DATA_XFER_NONE); > > +} > > + > > +static int litex_mmc_set_bus_width(struct litex_mmc_host *host) > > +{ > > + bool app_cmd_sent; > > + int ret; > > + > > + if (host->is_bus_width_set) > > + return 0; > > + > > + /* Ensure 'app_cmd' precedes 'app_set_bus_width_cmd' */ > > + app_cmd_sent = host->app_cmd; /* was preceding command app_cmd? */ > > + if (!app_cmd_sent) { > > + ret = litex_mmc_send_app_cmd(host); > > + if (ret) > > + return ret; > > + } > > + > > + /* LiteSDCard only supports 4-bit bus width */ > > + ret = litex_mmc_send_set_bus_w_cmd(host, MMC_BUS_WIDTH_4); > > + if (ret) > > + return ret; > > + > > + /* Re-send 'app_cmd' if necessary */ > > + if (app_cmd_sent) { > > + ret = litex_mmc_send_app_cmd(host); > > + if (ret) > > + return ret; > > + } > > + > > + host->is_bus_width_set = true; > > + > > + return 0; > > +} > > + > > +static int litex_mmc_get_cd(struct mmc_host *mmc) > > +{ > > + struct litex_mmc_host *host = mmc_priv(mmc); > > + int ret; > > + > > + if (!mmc_card_is_removable(mmc)) > > + return 1; > > + > > + ret = !litex_read8(host->sdphy + LITEX_PHY_CARDDETECT); > > + > > + /* Ensure bus width will be set (again) upon card (re)insertion */ > > + if (ret == 0) > > + host->is_bus_width_set = false; > > + > > + return ret; > > +} > > + > > +static irqreturn_t litex_mmc_interrupt(int irq, void *arg) > > +{ > > + struct mmc_host *mmc = arg; > > + struct litex_mmc_host *host = mmc_priv(mmc); > > + u32 pending = litex_read32(host->sdirq + LITEX_IRQ_PENDING); > > + > > + /* Check for card change interrupt */ > > + if (pending & SDIRQ_CARD_DETECT) { > > + litex_write32(host->sdirq + LITEX_IRQ_PENDING, > > + SDIRQ_CARD_DETECT); > > + mmc_detect_change(mmc, msecs_to_jiffies(10)); > > + } > > + > > + /* Check for command completed */ > > + if (pending & SDIRQ_CMD_DONE) { > > + /* Disable it so it doesn't keep interrupting */ > > + litex_write32(host->sdirq + LITEX_IRQ_ENABLE, > > + SDIRQ_CARD_DETECT); > > + complete(&host->cmd_done); > > + } > > + > > + return IRQ_HANDLED; > > +} > > + > > +static u32 litex_mmc_response_len(struct mmc_command *cmd) > > +{ > > + if (cmd->flags & MMC_RSP_136) > > + return SD_CTL_RESP_LONG; > > + if (!(cmd->flags & MMC_RSP_PRESENT)) > > + return SD_CTL_RESP_NONE; > > + if (cmd->flags & MMC_RSP_BUSY) > > + return SD_CTL_RESP_SHORT_BUSY; > > + return SD_CTL_RESP_SHORT; > > +} > > + > > +static void litex_mmc_do_dma(struct litex_mmc_host *host, struct mmc_data > > *data, > > + unsigned int *len, bool *direct, u8 *transfer) > > +{ > > + struct device *dev = mmc_dev(host->mmc); > > + dma_addr_t dma; > > + int sg_count; > > + > > + /* > > + * Try to DMA directly to/from the data buffer. > > + * We can do that if the buffer can be mapped for DMA > > + * in one contiguous chunk. > > + */ > > + dma = host->dma; > > + *len = data->blksz * data->blocks; > > + sg_count = dma_map_sg(dev, data->sg, data->sg_len, > > + mmc_get_dma_dir(data)); > > + if (sg_count == 1) { > > + dma = sg_dma_address(data->sg); > > + *len = sg_dma_len(data->sg); > > + *direct = true; > > + } else if (*len > host->buf_size) > > + *len = host->buf_size; > > + > > + if (data->flags & MMC_DATA_READ) { > > + litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0); > > + litex_write64(host->sdreader + LITEX_BLK2MEM_BASE, dma); > > + litex_write32(host->sdreader + LITEX_BLK2MEM_LEN, *len); > > + litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 1); > > + *transfer = SD_CTL_DATA_XFER_READ; > > + } else if (data->flags & MMC_DATA_WRITE) { > > + if (!*direct) > > + sg_copy_to_buffer(data->sg, data->sg_len, > > + host->buffer, *len); > > + litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0); > > + litex_write64(host->sdwriter + LITEX_MEM2BLK_BASE, dma); > > + litex_write32(host->sdwriter + LITEX_MEM2BLK_LEN, *len); > > + litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 1); > > + *transfer = SD_CTL_DATA_XFER_WRITE; > > + } else { > > + dev_warn(dev, "Data present w/o read or write flag.\n"); > > + /* Continue: set cmd status, mark req done */ > > + } > > + > > + litex_write16(host->sdcore + LITEX_CORE_BLKLEN, data->blksz); > > + litex_write32(host->sdcore + LITEX_CORE_BLKCNT, data->blocks); > > +} > > + > > +static void litex_mmc_request(struct mmc_host *mmc, struct mmc_request > > *mrq) > > +{ > > + struct litex_mmc_host *host = mmc_priv(mmc); > > + struct device *dev = mmc_dev(mmc); > > + struct mmc_command *cmd = mrq->cmd; > > + struct mmc_command *sbc = mrq->sbc; > > + struct mmc_data *data = mrq->data; > > + struct mmc_command *stop = mrq->stop; > > + unsigned int retries = cmd->retries; > > + unsigned int len = 0; > > + bool direct = false; > > + u32 response_len = litex_mmc_response_len(cmd); > > + u8 transfer = SD_CTL_DATA_XFER_NONE; > > + > > + /* First check that the card is still there */ > > + if (!litex_mmc_get_cd(mmc)) { > > + cmd->error = -ENOMEDIUM; > > + mmc_request_done(mmc, mrq); > > + return; > > + } > > + > > + /* Send set-block-count command if needed */ > > + if (sbc) { > > + sbc->error = litex_mmc_send_cmd(host, sbc->opcode, sbc-> > > arg, > > + litex_mmc_response_len > > (sbc), > > + SD_CTL_DATA_XFER_NONE); > > + if (sbc->error) { > > + host->is_bus_width_set = false; > > + mmc_request_done(mmc, mrq); > > + return; > > + } > > + } > > + > > + if (data) { > > + /* > > + * LiteSDCard only supports 4-bit bus width; therefore, we > > MUST > > + * inject a SET_BUS_WIDTH (acmd6) before the very first > > data > > + * transfer, earlier than when the mmc subsystem would > > normally > > + * get around to it! > > + */ > > + cmd->error = litex_mmc_set_bus_width(host); > > + if (cmd->error) { > > + dev_err(dev, "Can't set bus width!\n"); > > + mmc_request_done(mmc, mrq); > > + return; > > + } > > + > > + litex_mmc_do_dma(host, data, &len, &direct, &transfer); > > + } > > + > > + do { > > + cmd->error = litex_mmc_send_cmd(host, cmd->opcode, cmd-> > > arg, > > + response_len, transfer); > > + } while (cmd->error && retries-- > 0); > > + > > + if (cmd->error) { > > + /* Card may be gone; don't assume bus width is still set */ > > + host->is_bus_width_set = false; > > + } > > + > > + if (response_len == SD_CTL_RESP_SHORT) { > > + /* Pull short response fields from appropriate host > > registers */ > > + cmd->resp[0] = host->resp[3]; > > + cmd->resp[1] = host->resp[2] & 0xFF; > > + } else if (response_len == SD_CTL_RESP_LONG) { > > + cmd->resp[0] = host->resp[0]; > > + cmd->resp[1] = host->resp[1]; > > + cmd->resp[2] = host->resp[2]; > > + cmd->resp[3] = host->resp[3]; > > + } > > + > > + /* Send stop-transmission command if required */ > > + if (stop && (cmd->error || !sbc)) { > > + stop->error = litex_mmc_send_cmd(host, stop->opcode, stop-> > > arg, > > + litex_mmc_response_len > > (stop), > > + SD_CTL_DATA_XFER_NONE); > > + if (stop->error) > > + host->is_bus_width_set = false; > > + } > > + > > + if (data) { > > + dma_unmap_sg(dev, data->sg, data->sg_len, > > + mmc_get_dma_dir(data)); > > + } > > + > > + if (!cmd->error && transfer != SD_CTL_DATA_XFER_NONE) { > > + data->bytes_xfered = min(len, mmc->max_req_size); > > + if (transfer == SD_CTL_DATA_XFER_READ && !direct) { > > + sg_copy_from_buffer(data->sg, sg_nents(data->sg), > > + host->buffer, data-> > > bytes_xfered); > > + } > > + } > > + > > + mmc_request_done(mmc, mrq); > > +} > > + > > +static void litex_mmc_setclk(struct litex_mmc_host *host, unsigned int > > freq) > > +{ > > + struct device *dev = mmc_dev(host->mmc); > > + u32 div; > > + > > + div = freq ? host->ref_clk / freq : 256U; > > > > > > > > + div = roundup_pow_of_two(div); > > + div = clamp(div, 2U, 256U); > > > > > > Logically seems to me that you may join these two together, because clamped > > range is power-of-2 one. > > `div` needs to be a power-of-2 when written to the LITEX_PHY_CLOCKERDIV > register (below). And clamp() will just enforce a min/max range, so if > (div = ref_clk / freq) ends up e.g., 5, I need both roundup_pow_of_two() > to bump it to 8, and clamp() to enforce that it's between 2 and 256. > > Unless you mean I should simply write it like: > > div = clamp(roundup_pow_of_two(div), 2U, 256U); > > ... as a single line? > > > + dev_dbg(dev, "sd_clk_freq=%d: set to %d via div=%d\n", > > + freq, host->ref_clk / div, div); > > + litex_write16(host->sdphy + LITEX_PHY_CLOCKERDIV, div); > > + host->sd_clk = freq; > > +} > > + > > +static void litex_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) > > +{ > > + struct litex_mmc_host *host = mmc_priv(mmc); > > + > > + /* > > + * NOTE: Ignore any ios->bus_width updates; they occur right after > > + * the mmc core sends its own acmd6 bus-width change notification, > > + * which is redundant since we snoop on the command flow and inject > > + * an early acmd6 before the first data transfer command is sent! > > + */ > > + > > + /* Update sd_clk */ > > + if (ios->clock != host->sd_clk) > > + litex_mmc_setclk(host, ios->clock); > > +} > > + > > +static const struct mmc_host_ops litex_mmc_ops = { > > + .get_cd = litex_mmc_get_cd, > > + .request = litex_mmc_request, > > + .set_ios = litex_mmc_set_ios, > > +}; > > + > > +static int litex_mmc_irq_init(struct litex_mmc_host *host) > > +{ > > + struct device *dev = mmc_dev(host->mmc); > > + int ret; > > + > > + ret = platform_get_irq_optional(host->dev, 0); > > + if (ret < 0 && ret != -ENXIO) > > + return ret; > > + if (ret > 0) > > + host->irq = ret; > > + else { > > + dev_warn(dev, "Failed to get IRQ, using polling\n"); > > + goto use_polling; > > + } > > + > > + host->sdirq = devm_platform_ioremap_resource_byname(host->dev, > > "irq"); > > + if (IS_ERR(host->sdirq)) > > + return PTR_ERR(host->sdirq); > > + > > + ret = devm_request_irq(dev, host->irq, litex_mmc_interrupt, 0, > > + "litex-mmc", host->mmc); > > + if (ret < 0) { > > + dev_warn(dev, "IRQ request error %d, using polling\n", > > ret); > > + goto use_polling; > > + } > > + > > + /* Clear & enable card-change interrupts */ > > + litex_write32(host->sdirq + LITEX_IRQ_PENDING, SDIRQ_CARD_DETECT); > > + litex_write32(host->sdirq + LITEX_IRQ_ENABLE, SDIRQ_CARD_DETECT); > > + > > + return 0; > > + > > +use_polling: > > + host->mmc->caps |= MMC_CAP_NEEDS_POLL; > > + return 0; > > +} > > + > > +static int litex_mmc_probe(struct platform_device *pdev) > > +{ > > + struct litex_mmc_host *host; > > + struct mmc_host *mmc; > > + struct clk *clk; > > + int ret; > > + > > + /* > > + * NOTE: defaults to max_[req,seg]_size=PAGE_SIZE, max_blk_size= > > 512, > > + * and max_blk_count accordingly set to 8; > > + * If for some reason we need to modify max_blk_count, we must also > > + * re-calculate `max_[req,seg]_size = max_blk_size * max_blk_count; > > ` > > + */ > > + mmc = mmc_alloc_host(sizeof(struct litex_mmc_host), &pdev->dev); > > > > > > Should be devm or you may not use devm at all. See hint in one of the previous > > messages in v7 discussion. > > And here I think I'm in trouble... :) > > None of the examples retrieved via > > `git log --no-merges --grep devm_add_action_or_reset` > > are from "drivers/mmc/host/*", and *all* of the mmc drivers there, > including the ones that make extensive use of devm_*, use > mmc_alloc_host(), and there doesn't appear to be a devm-ified version > of mmc_alloc_host() available! How do they all get away with it? > > I'm really confused now -- any additional clue(s) much appreciated! I found drivers/mmc/host/meson-mx-sdhc-mmc.c, which uses devm_add_action_or_reset() right after mmc_alloc_host() to enlist the subsequent call to mmc_free_host(), see here: https://github.com/torvalds/linux/blob/master/drivers/mmc/host/meson-mx-sdhc-mmc.c#L791 This would mean that I no longer have to call mmc_free_host(), neither on probe()'s error path, nor during remove(). Does that count as canonically correct, or am I still missing something? Thanks, as always, --Gabriel > > + if (!mmc) > > + return -ENOMEM; > > + > > + host = mmc_priv(mmc); > > + host->mmc = mmc; > > + host->dev = pdev; > > + > > + /* Initialize clock source */ > > + clk = devm_clk_get(&pdev->dev, NULL); > > + if (IS_ERR(clk)) { > > + ret = dev_err_probe(&pdev->dev, > > + PTR_ERR(clk), "can't get clock\n"); > > + goto err; > > + } > > + host->ref_clk = clk_get_rate(clk); > > + host->sd_clk = 0; > > + > > + /* > > + * LiteSDCard only supports 4-bit bus width; therefore, we MUST > > inject > > + * a SET_BUS_WIDTH (acmd6) before the very first data transfer, > > earlier > > + * than when the mmc subsystem would normally get around to it! > > + */ > > + host->is_bus_width_set = false; > > + host->app_cmd = false; > > + > > + /* LiteSDCard can support 64-bit DMA addressing */ > > + ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); > > + if (ret) > > + goto err; > > + > > + host->buf_size = mmc->max_req_size * 2; > > + host->buffer = dmam_alloc_coherent(&pdev->dev, host->buf_size, > > + &host->dma, GFP_DMA); > > + if (host->buffer == NULL) { > > + ret = -ENOMEM; > > + goto err; > > + } > > + > > + host->sdphy = devm_platform_ioremap_resource_byname(pdev, "phy"); > > + if (IS_ERR(host->sdphy)) { > > + ret = PTR_ERR(host->sdphy); > > + goto err; > > + } > > + > > + host->sdcore = devm_platform_ioremap_resource_byname(pdev, "core"); > > + if (IS_ERR(host->sdcore)) { > > + ret = PTR_ERR(host->sdcore); > > + goto err; > > + } > > + > > + host->sdreader = devm_platform_ioremap_resource_byname(pdev, > > "reader"); > > + if (IS_ERR(host->sdreader)) { > > + ret = PTR_ERR(host->sdreader); > > + goto err; > > + } > > + > > + host->sdwriter = devm_platform_ioremap_resource_byname(pdev, > > "writer"); > > + if (IS_ERR(host->sdwriter)) { > > + ret = PTR_ERR(host->sdwriter); > > + goto err; > > + } > > + > > + /* Ensure DMA bus masters are disabled */ > > + litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0); > > + litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0); > > + > > + init_completion(&host->cmd_done); > > + ret = litex_mmc_irq_init(host); > > + if (ret) > > + goto err; > > + > > + /* Allow full generic 2.7-3.6V range; no software tuning available > > */ > > + mmc->ocr_avail = LITEX_MMC_OCR; > > + > > + mmc->ops = &litex_mmc_ops; > > + > > + /* > > + * Set default sd_clk frequency range based on empirical > > observations > > + * of LiteSDCard gateware behavior on typical SDCard media > > + */ > > + mmc->f_min = 12.5e6; > > + mmc->f_max = 50e6; > > + > > + ret = mmc_of_parse(mmc); > > + if (ret) > > + goto err; > > + > > + /* Force 4-bit bus_width (only width supported by hardware) */ > > + mmc->caps &= ~MMC_CAP_8_BIT_DATA; > > + mmc->caps |= MMC_CAP_4_BIT_DATA; > > + > > + /* Set default capabilities */ > > + mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY | > > + MMC_CAP_DRIVER_TYPE_D | > > + MMC_CAP_CMD23; > > + mmc->caps2 |= MMC_CAP2_NO_WRITE_PROTECT | > > + MMC_CAP2_NO_SDIO | > > + MMC_CAP2_NO_MMC; > > + > > + platform_set_drvdata(pdev, host); > > + > > + ret = mmc_add_host(mmc); > > + if (ret < 0) > > + goto err; > > + > > + return 0; > > + > > +err: > > + mmc_free_host(mmc); > > + return ret; > > +} > > + > > +static int litex_mmc_remove(struct platform_device *pdev) > > +{ > > + struct litex_mmc_host *host = platform_get_drvdata(pdev); > > + struct mmc_host *mmc = host->mmc; > > + > > + mmc_remove_host(mmc); > > + mmc_free_host(mmc); > > + > > + return 0; > > +} > > + > > +static const struct of_device_id litex_match[] = { > > + { .compatible = "litex,mmc" }, > > + { } > > +}; > > +MODULE_DEVICE_TABLE(of, litex_match); > > + > > +static struct platform_driver litex_mmc_driver = { > > + .probe = litex_mmc_probe, > > + .remove = litex_mmc_remove, > > + .driver = { > > + .name = "litex-mmc", > > + .of_match_table = litex_match, > > + }, > > +}; > > +module_platform_driver(litex_mmc_driver); > > + > > +MODULE_DESCRIPTION("LiteX SDCard driver"); > > +MODULE_AUTHOR("Antmicro <contact@antmicro.com>"); > > +MODULE_AUTHOR("Kamil Rakoczy <krakoczy@antmicro.com>"); > > +MODULE_AUTHOR("Maciej Dudek <mdudek@internships.antmicro.com>"); > > +MODULE_AUTHOR("Paul Mackerras <paulus@ozlabs.org>"); > > +MODULE_AUTHOR("Gabriel Somlo <gsomlo@gmail.com>"); > > +MODULE_LICENSE("GPL v2"); > > -- > > 2.31.1 > > > > > > > > > > -- > > With Best Regards, > > Andy Shevchenko > > > > ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v8 3/3] mmc: Add driver for LiteX's LiteSDCard interface 2022-01-08 2:31 ` Gabriel L. Somlo @ 2022-01-08 11:29 ` Andy Shevchenko 0 siblings, 0 replies; 12+ messages in thread From: Andy Shevchenko @ 2022-01-08 11:29 UTC (permalink / raw) To: Gabriel L. Somlo Cc: linux-kernel, robh+dt, devicetree, ulf.hansson, linux-mmc, kgugala, mholenko, krakoczy, mdudek, paulus, joel, shorne, geert, david.abdurachmanov, florent, rdunlap On Sat, Jan 8, 2022 at 4:32 AM Gabriel L. Somlo <gsomlo@gmail.com> wrote: > On Fri, Jan 07, 2022 at 08:57:43PM -0500, Gabriel L. Somlo wrote: > > On Sat, Jan 08, 2022 at 01:54:07AM +0200, Andy Shevchenko wrote: > > > On Saturday, January 8, 2022, Gabriel Somlo <gsomlo@gmail.com> wrote: ... > > > + mmc = mmc_alloc_host(sizeof(struct litex_mmc_host), &pdev->dev); > > > > > > Should be devm or you may not use devm at all. See hint in one of the previous > > > messages in v7 discussion. > > > > And here I think I'm in trouble... :) > > > > None of the examples retrieved via > > > > `git log --no-merges --grep devm_add_action_or_reset` > > > > are from "drivers/mmc/host/*", and *all* of the mmc drivers there, > > including the ones that make extensive use of devm_*, use > > mmc_alloc_host(), and there doesn't appear to be a devm-ified version > > of mmc_alloc_host() available! How do they all get away with it? > > > > I'm really confused now -- any additional clue(s) much appreciated! > > I found drivers/mmc/host/meson-mx-sdhc-mmc.c, which uses > devm_add_action_or_reset() right after mmc_alloc_host() to enlist the > subsequent call to mmc_free_host(), see here: > > https://github.com/torvalds/linux/blob/master/drivers/mmc/host/meson-mx-sdhc-mmc.c#L791 > > This would mean that I no longer have to call mmc_free_host(), neither > on probe()'s error path, nor during remove(). > > Does that count as canonically correct, or am I still missing > something? Yes, this is one of the options you may use. Since it will be a second (?) driver with the same idea, perhaps in the future it would make sense to provide devm_mmc_alloc_host() or analogue (in the latter it means more complex solution like the input subsystem is using, see devm_input_... API implementations). -- With Best Regards, Andy Shevchenko ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v8 3/3] mmc: Add driver for LiteX's LiteSDCard interface 2022-01-08 1:57 ` Gabriel L. Somlo 2022-01-08 2:31 ` Gabriel L. Somlo @ 2022-01-08 11:26 ` Andy Shevchenko 2022-01-08 13:20 ` Gabriel L. Somlo 1 sibling, 1 reply; 12+ messages in thread From: Andy Shevchenko @ 2022-01-08 11:26 UTC (permalink / raw) To: Gabriel L. Somlo Cc: linux-kernel, robh+dt, devicetree, ulf.hansson, linux-mmc, kgugala, mholenko, krakoczy, mdudek, paulus, joel, shorne, geert, david.abdurachmanov, florent, rdunlap On Sat, Jan 8, 2022 at 3:57 AM Gabriel L. Somlo <gsomlo@gmail.com> wrote: > On Sat, Jan 08, 2022 at 01:54:07AM +0200, Andy Shevchenko wrote: > > On Saturday, January 8, 2022, Gabriel Somlo <gsomlo@gmail.com> wrote: ... > > Almost > > That's encouraging! Thanks for your ongoing time and attention! :) It's true from my perspective, but I'm not a maintainer here :-) ... > > +#include <linux/of.h> > > > > Is it used anywhere? Or you meant mod_devicetable.h? > > Not used since I dropped `of_match_ptr()`, so I'm removing the > include in v9 as well -- thanks for catching that! Don't forget to use mod_devicetable.h, though. ... > > + u32 div; > > + > > + div = freq ? host->ref_clk / freq : 256U; > > > > + div = roundup_pow_of_two(div); > > + div = clamp(div, 2U, 256U); > > > > Logically seems to me that you may join these two together, because clamped > > range is power-of-2 one. > > `div` needs to be a power-of-2 when written to the LITEX_PHY_CLOCKERDIV > register (below). And clamp() will just enforce a min/max range, so if > (div = ref_clk / freq) ends up e.g., 5, I need both roundup_pow_of_two() > to bump it to 8, and clamp() to enforce that it's between 2 and 256. > > Unless you mean I should simply write it like: > > div = clamp(roundup_pow_of_two(div), 2U, 256U); > > ... as a single line? Yes, that's what I meant. ... > > + mmc = mmc_alloc_host(sizeof(struct litex_mmc_host), &pdev->dev); > > > > > > Should be devm or you may not use devm at all. See hint in one of the previous > > messages in v7 discussion. > > And here I think I'm in trouble... :) > > None of the examples retrieved via > > `git log --no-merges --grep devm_add_action_or_reset` > > are from "drivers/mmc/host/*", and *all* of the mmc drivers there, > including the ones that make extensive use of devm_*, use > mmc_alloc_host(), and there doesn't appear to be a devm-ified version > of mmc_alloc_host() available! How do they all get away with it? > > I'm really confused now -- any additional clue(s) much appreciated! There are basically three options: - switch to non-devm - switch to devm: a) if there is an API, b) using devm_add_action_or_reset() helper - shuffle code around to make sure all devm followed by all non-devm. -- With Best Regards, Andy Shevchenko ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v8 3/3] mmc: Add driver for LiteX's LiteSDCard interface 2022-01-08 11:26 ` Andy Shevchenko @ 2022-01-08 13:20 ` Gabriel L. Somlo 2022-01-08 17:47 ` Andy Shevchenko 0 siblings, 1 reply; 12+ messages in thread From: Gabriel L. Somlo @ 2022-01-08 13:20 UTC (permalink / raw) To: Andy Shevchenko Cc: linux-kernel, robh+dt, devicetree, ulf.hansson, linux-mmc, kgugala, mholenko, krakoczy, mdudek, paulus, joel, shorne, geert, david.abdurachmanov, florent, rdunlap On Sat, Jan 08, 2022 at 01:26:08PM +0200, Andy Shevchenko wrote: > On Sat, Jan 8, 2022 at 3:57 AM Gabriel L. Somlo <gsomlo@gmail.com> wrote: > > On Sat, Jan 08, 2022 at 01:54:07AM +0200, Andy Shevchenko wrote: > > > On Saturday, January 8, 2022, Gabriel Somlo <gsomlo@gmail.com> wrote: > > > > + u32 div; > > > + > > > + div = freq ? host->ref_clk / freq : 256U; > > > > > > + div = roundup_pow_of_two(div); > > > + div = clamp(div, 2U, 256U); > > > > > > Logically seems to me that you may join these two together, because clamped > > > range is power-of-2 one. > > > > `div` needs to be a power-of-2 when written to the LITEX_PHY_CLOCKERDIV > > register (below). And clamp() will just enforce a min/max range, so if > > (div = ref_clk / freq) ends up e.g., 5, I need both roundup_pow_of_two() > > to bump it to 8, and clamp() to enforce that it's between 2 and 256. > > > > Unless you mean I should simply write it like: > > > > div = clamp(roundup_pow_of_two(div), 2U, 256U); > > > > ... as a single line? > > Yes, that's what I meant. Turns out, clamp really hates being passed roundup_pow_of_two() directly (see below). I think it's probably better if we leave them as-is, to avoid going the explicit cast route which Geert recommended against. I'll send out v9 later today with everything else, including devm_add_action_or_reset(). Thanks, --Gabriel drivers/mmc/host/litex_mmc.c: In function 'litex_mmc_setclk': ./include/linux/minmax.h:20:35: warning: comparison of distinct pointer types lacks a cast 20 | (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1))) | ^~ ./include/linux/minmax.h:26:18: note: in expansion of macro '__typecheck' 26 | (__typecheck(x, y) && __no_side_effects(x, y)) | ^~~~~~~~~~~ ./include/linux/minmax.h:36:31: note: in expansion of macro '__safe_cmp' 36 | __builtin_choose_expr(__safe_cmp(x, y), \ | ^~~~~~~~~~ ./include/linux/minmax.h:45:25: note: in expansion of macro '__careful_cmp' 45 | #define min(x, y) __careful_cmp(x, y, <) | ^~~~~~~~~~~~~ ./include/linux/minmax.h:89:28: note: in expansion of macro 'min' 89 | #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) | ^~~ ./include/linux/minmax.h:26:18: note: in expansion of macro '__typecheck' 26 | (__typecheck(x, y) && __no_side_effects(x, y)) | ^~~~~~~~~~~ ./include/linux/minmax.h:36:31: note: in expansion of macro '__safe_cmp' 36 | __builtin_choose_expr(__safe_cmp(x, y), \ | ^~~~~~~~~~ ./include/linux/minmax.h:52:25: note: in expansion of macro '__careful_cmp' 52 | #define max(x, y) __careful_cmp(x, y, >) | ^~~~~~~~~~~~~ ./include/linux/minmax.h:89:45: note: in expansion of macro 'max' 89 | #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) | ^~~ drivers/mmc/host/litex_mmc.c:448:15: note: in expansion of macro 'clamp' 448 | div = clamp(roundup_pow_of_two(div), 2U, 256U); | ^~~~~ ./include/linux/minmax.h:20:35: warning: comparison of distinct pointer types lacks a cast 20 | (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1))) | ^~ ./include/linux/minmax.h:26:18: note: in expansion of macro '__typecheck' 26 | (__typecheck(x, y) && __no_side_effects(x, y)) | ^~~~~~~~~~~ ./include/linux/minmax.h:36:31: note: in expansion of macro '__safe_cmp' 36 | __builtin_choose_expr(__safe_cmp(x, y), \ | ^~~~~~~~~~ ./include/linux/minmax.h:45:25: note: in expansion of macro '__careful_cmp' 45 | #define min(x, y) __careful_cmp(x, y, <) | ^~~~~~~~~~~~~ ./include/linux/minmax.h:89:28: note: in expansion of macro 'min' 89 | #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) | ^~~ drivers/mmc/host/litex_mmc.c:448:15: note: in expansion of macro 'clamp' 448 | div = clamp(roundup_pow_of_two(div), 2U, 256U); | ^~~~~ In file included from ./include/linux/bits.h:5, from drivers/mmc/host/litex_mmc.c:12: ./include/linux/minmax.h:20:35: warning: comparison of distinct pointer types lacks a cast 20 | (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1))) | ^~ ./include/linux/const.h:12:55: note: in definition of macro '__is_constexpr' 12 | (sizeof(int) == sizeof(*(8 ? ((void *)((long)(x) * 0l)) : (int *)8))) | ^ ./include/linux/minmax.h:26:39: note: in expansion of macro '__no_side_effects' 26 | (__typecheck(x, y) && __no_side_effects(x, y)) | ^~~~~~~~~~~~~~~~~ ./include/linux/minmax.h:36:31: note: in expansion of macro '__safe_cmp' 36 | __builtin_choose_expr(__safe_cmp(x, y), \ | ^~~~~~~~~~ ./include/linux/minmax.h:45:25: note: in expansion of macro '__careful_cmp' 45 | #define min(x, y) __careful_cmp(x, y, <) | ^~~~~~~~~~~~~ ./include/linux/minmax.h:89:28: note: in expansion of macro 'min' 89 | #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) | ^~~ ./include/linux/minmax.h:26:18: note: in expansion of macro '__typecheck' 26 | (__typecheck(x, y) && __no_side_effects(x, y)) | ^~~~~~~~~~~ ./include/linux/minmax.h:36:31: note: in expansion of macro '__safe_cmp' 36 | __builtin_choose_expr(__safe_cmp(x, y), \ | ^~~~~~~~~~ ./include/linux/minmax.h:52:25: note: in expansion of macro '__careful_cmp' 52 | #define max(x, y) __careful_cmp(x, y, >) | ^~~~~~~~~~~~~ ./include/linux/minmax.h:89:45: note: in expansion of macro 'max' 89 | #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) | ^~~ drivers/mmc/host/litex_mmc.c:448:15: note: in expansion of macro 'clamp' 448 | div = clamp(roundup_pow_of_two(div), 2U, 256U); | ^~~~~ In file included from ./include/linux/kernel.h:17, from ./include/linux/clk.h:13, from drivers/mmc/host/litex_mmc.c:13: ./include/linux/minmax.h:20:35: warning: comparison of distinct pointer types lacks a cast 20 | (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1))) | ^~ ./include/linux/minmax.h:28:27: note: in definition of macro '__cmp' 28 | #define __cmp(x, y, op) ((x) op (y) ? (x) : (y)) | ^ ./include/linux/minmax.h:45:25: note: in expansion of macro '__careful_cmp' 45 | #define min(x, y) __careful_cmp(x, y, <) | ^~~~~~~~~~~~~ ./include/linux/minmax.h:89:28: note: in expansion of macro 'min' 89 | #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) | ^~~ ./include/linux/minmax.h:26:18: note: in expansion of macro '__typecheck' 26 | (__typecheck(x, y) && __no_side_effects(x, y)) | ^~~~~~~~~~~ ./include/linux/minmax.h:36:31: note: in expansion of macro '__safe_cmp' 36 | __builtin_choose_expr(__safe_cmp(x, y), \ | ^~~~~~~~~~ ./include/linux/minmax.h:52:25: note: in expansion of macro '__careful_cmp' 52 | #define max(x, y) __careful_cmp(x, y, >) | ^~~~~~~~~~~~~ ./include/linux/minmax.h:89:45: note: in expansion of macro 'max' 89 | #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) | ^~~ drivers/mmc/host/litex_mmc.c:448:15: note: in expansion of macro 'clamp' 448 | div = clamp(roundup_pow_of_two(div), 2U, 256U); | ^~~~~ ./include/linux/minmax.h:20:35: warning: comparison of distinct pointer types lacks a cast 20 | (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1))) | ^~ ./include/linux/minmax.h:28:40: note: in definition of macro '__cmp' 28 | #define __cmp(x, y, op) ((x) op (y) ? (x) : (y)) | ^ ./include/linux/minmax.h:45:25: note: in expansion of macro '__careful_cmp' 45 | #define min(x, y) __careful_cmp(x, y, <) | ^~~~~~~~~~~~~ ./include/linux/minmax.h:89:28: note: in expansion of macro 'min' 89 | #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) | ^~~ ./include/linux/minmax.h:26:18: note: in expansion of macro '__typecheck' 26 | (__typecheck(x, y) && __no_side_effects(x, y)) | ^~~~~~~~~~~ ./include/linux/minmax.h:36:31: note: in expansion of macro '__safe_cmp' 36 | __builtin_choose_expr(__safe_cmp(x, y), \ | ^~~~~~~~~~ ./include/linux/minmax.h:52:25: note: in expansion of macro '__careful_cmp' 52 | #define max(x, y) __careful_cmp(x, y, >) | ^~~~~~~~~~~~~ ./include/linux/minmax.h:89:45: note: in expansion of macro 'max' 89 | #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) | ^~~ drivers/mmc/host/litex_mmc.c:448:15: note: in expansion of macro 'clamp' 448 | div = clamp(roundup_pow_of_two(div), 2U, 256U); | ^~~~~ ./include/linux/minmax.h:20:35: warning: comparison of distinct pointer types lacks a cast 20 | (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1))) | ^~ ./include/linux/minmax.h:31:24: note: in definition of macro '__cmp_once' 31 | typeof(x) unique_x = (x); \ | ^ ./include/linux/minmax.h:45:25: note: in expansion of macro '__careful_cmp' 45 | #define min(x, y) __careful_cmp(x, y, <) | ^~~~~~~~~~~~~ ./include/linux/minmax.h:89:28: note: in expansion of macro 'min' 89 | #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) | ^~~ ./include/linux/minmax.h:26:18: note: in expansion of macro '__typecheck' 26 | (__typecheck(x, y) && __no_side_effects(x, y)) | ^~~~~~~~~~~ ./include/linux/minmax.h:36:31: note: in expansion of macro '__safe_cmp' 36 | __builtin_choose_expr(__safe_cmp(x, y), \ | ^~~~~~~~~~ ./include/linux/minmax.h:52:25: note: in expansion of macro '__careful_cmp' 52 | #define max(x, y) __careful_cmp(x, y, >) | ^~~~~~~~~~~~~ ./include/linux/minmax.h:89:45: note: in expansion of macro 'max' 89 | #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) | ^~~ drivers/mmc/host/litex_mmc.c:448:15: note: in expansion of macro 'clamp' 448 | div = clamp(roundup_pow_of_two(div), 2U, 256U); | ^~~~~ ./include/linux/minmax.h:20:35: warning: comparison of distinct pointer types lacks a cast 20 | (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1))) | ^~ ./include/linux/minmax.h:31:39: note: in definition of macro '__cmp_once' 31 | typeof(x) unique_x = (x); \ | ^ ./include/linux/minmax.h:45:25: note: in expansion of macro '__careful_cmp' 45 | #define min(x, y) __careful_cmp(x, y, <) | ^~~~~~~~~~~~~ ./include/linux/minmax.h:89:28: note: in expansion of macro 'min' 89 | #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) | ^~~ ./include/linux/minmax.h:26:18: note: in expansion of macro '__typecheck' 26 | (__typecheck(x, y) && __no_side_effects(x, y)) | ^~~~~~~~~~~ ./include/linux/minmax.h:36:31: note: in expansion of macro '__safe_cmp' 36 | __builtin_choose_expr(__safe_cmp(x, y), \ | ^~~~~~~~~~ ./include/linux/minmax.h:52:25: note: in expansion of macro '__careful_cmp' 52 | #define max(x, y) __careful_cmp(x, y, >) | ^~~~~~~~~~~~~ ./include/linux/minmax.h:89:45: note: in expansion of macro 'max' 89 | #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) | ^~~ drivers/mmc/host/litex_mmc.c:448:15: note: in expansion of macro 'clamp' 448 | div = clamp(roundup_pow_of_two(div), 2U, 256U); | ^~~~~ ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v8 3/3] mmc: Add driver for LiteX's LiteSDCard interface 2022-01-08 13:20 ` Gabriel L. Somlo @ 2022-01-08 17:47 ` Andy Shevchenko 2022-01-08 23:51 ` Gabriel L. Somlo 0 siblings, 1 reply; 12+ messages in thread From: Andy Shevchenko @ 2022-01-08 17:47 UTC (permalink / raw) To: Gabriel L. Somlo Cc: linux-kernel, robh+dt, devicetree, ulf.hansson, linux-mmc, kgugala, mholenko, krakoczy, mdudek, paulus, joel, shorne, geert, david.abdurachmanov, florent, rdunlap On Sat, Jan 8, 2022 at 3:20 PM Gabriel L. Somlo <gsomlo@gmail.com> wrote: > On Sat, Jan 08, 2022 at 01:26:08PM +0200, Andy Shevchenko wrote: > > On Sat, Jan 8, 2022 at 3:57 AM Gabriel L. Somlo <gsomlo@gmail.com> wrote: > > > On Sat, Jan 08, 2022 at 01:54:07AM +0200, Andy Shevchenko wrote: > > > > On Saturday, January 8, 2022, Gabriel Somlo <gsomlo@gmail.com> wrote: ... > > > > + u32 div; > > > > + > > > > + div = freq ? host->ref_clk / freq : 256U; > > > > > > > > + div = roundup_pow_of_two(div); > > > > + div = clamp(div, 2U, 256U); > > > > > > > > Logically seems to me that you may join these two together, because clamped > > > > range is power-of-2 one. > > > > > > `div` needs to be a power-of-2 when written to the LITEX_PHY_CLOCKERDIV > > > register (below). And clamp() will just enforce a min/max range, so if > > > (div = ref_clk / freq) ends up e.g., 5, I need both roundup_pow_of_two() > > > to bump it to 8, and clamp() to enforce that it's between 2 and 256. > > > > > > Unless you mean I should simply write it like: > > > > > > div = clamp(roundup_pow_of_two(div), 2U, 256U); > > > > > > ... as a single line? > > > > Yes, that's what I meant. > > Turns out, clamp really hates being passed roundup_pow_of_two() > directly (see below). I think it's probably better if we leave > them as-is, to avoid going the explicit cast route which Geert > recommended against. I see, then ignore my comment on this matter in v9. Perhaps add a comment in the code explaining that roundup_pow_of_two() may not be unified with clamp()? -- With Best Regards, Andy Shevchenko ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v8 3/3] mmc: Add driver for LiteX's LiteSDCard interface 2022-01-08 17:47 ` Andy Shevchenko @ 2022-01-08 23:51 ` Gabriel L. Somlo 2022-01-09 11:36 ` Andy Shevchenko 0 siblings, 1 reply; 12+ messages in thread From: Gabriel L. Somlo @ 2022-01-08 23:51 UTC (permalink / raw) To: Andy Shevchenko Cc: linux-kernel, robh+dt, devicetree, ulf.hansson, linux-mmc, kgugala, mholenko, krakoczy, mdudek, paulus, joel, shorne, geert, david.abdurachmanov, florent, rdunlap On Sat, Jan 08, 2022 at 07:47:32PM +0200, Andy Shevchenko wrote: > On Sat, Jan 8, 2022 at 3:20 PM Gabriel L. Somlo <gsomlo@gmail.com> wrote: > > On Sat, Jan 08, 2022 at 01:26:08PM +0200, Andy Shevchenko wrote: > > > On Sat, Jan 8, 2022 at 3:57 AM Gabriel L. Somlo <gsomlo@gmail.com> wrote: > > > > On Sat, Jan 08, 2022 at 01:54:07AM +0200, Andy Shevchenko wrote: > > > > > On Saturday, January 8, 2022, Gabriel Somlo <gsomlo@gmail.com> wrote: > > ... > > > > > > + u32 div; > > > > > + > > > > > + div = freq ? host->ref_clk / freq : 256U; > > > > > > > > > > + div = roundup_pow_of_two(div); > > > > > + div = clamp(div, 2U, 256U); > > > > > > > > > > Logically seems to me that you may join these two together, because clamped > > > > > range is power-of-2 one. > > > > > > > > `div` needs to be a power-of-2 when written to the LITEX_PHY_CLOCKERDIV > > > > register (below). And clamp() will just enforce a min/max range, so if > > > > (div = ref_clk / freq) ends up e.g., 5, I need both roundup_pow_of_two() > > > > to bump it to 8, and clamp() to enforce that it's between 2 and 256. > > > > > > > > Unless you mean I should simply write it like: > > > > > > > > div = clamp(roundup_pow_of_two(div), 2U, 256U); > > > > > > > > ... as a single line? > > > > > > Yes, that's what I meant. > > > > Turns out, clamp really hates being passed roundup_pow_of_two() > > directly (see below). I think it's probably better if we leave > > them as-is, to avoid going the explicit cast route which Geert > > recommended against. > > I see, then ignore my comment on this matter in v9. > Perhaps add a comment in the code explaining that roundup_pow_of_two() > may not be unified with clamp()? I worry that commenting on why things are not done some other way at that location would detract from the legibility of the code itself. Perhaps we could use a cast after all, and write it out like this: div = clamp((u32)roundup_pow_of_two(div), 2U, 256U); which compiles fine without any warnings, accomplishes your "do it in a single line" desired behavior, and doesn't require me commenting on which linux library functions do or don't work well with others... :) Geert, what do you think? Thanks, --Gabriel ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v8 3/3] mmc: Add driver for LiteX's LiteSDCard interface 2022-01-08 23:51 ` Gabriel L. Somlo @ 2022-01-09 11:36 ` Andy Shevchenko 0 siblings, 0 replies; 12+ messages in thread From: Andy Shevchenko @ 2022-01-09 11:36 UTC (permalink / raw) To: Gabriel L. Somlo Cc: linux-kernel, robh+dt, devicetree, ulf.hansson, linux-mmc, kgugala, mholenko, krakoczy, mdudek, paulus, joel, shorne, geert, david.abdurachmanov, florent, rdunlap On Sun, Jan 9, 2022 at 1:51 AM Gabriel L. Somlo <gsomlo@gmail.com> wrote: > > On Sat, Jan 08, 2022 at 07:47:32PM +0200, Andy Shevchenko wrote: > > On Sat, Jan 8, 2022 at 3:20 PM Gabriel L. Somlo <gsomlo@gmail.com> wrote: > > > On Sat, Jan 08, 2022 at 01:26:08PM +0200, Andy Shevchenko wrote: > > > > On Sat, Jan 8, 2022 at 3:57 AM Gabriel L. Somlo <gsomlo@gmail.com> wrote: > > > > > On Sat, Jan 08, 2022 at 01:54:07AM +0200, Andy Shevchenko wrote: > > > > > > On Saturday, January 8, 2022, Gabriel Somlo <gsomlo@gmail.com> wrote: > > > > ... > > > > > > > > + u32 div; > > > > > > + > > > > > > + div = freq ? host->ref_clk / freq : 256U; > > > > > > > > > > > > + div = roundup_pow_of_two(div); > > > > > > + div = clamp(div, 2U, 256U); > > > > > > > > > > > > Logically seems to me that you may join these two together, because clamped > > > > > > range is power-of-2 one. > > > > > > > > > > `div` needs to be a power-of-2 when written to the LITEX_PHY_CLOCKERDIV > > > > > register (below). And clamp() will just enforce a min/max range, so if > > > > > (div = ref_clk / freq) ends up e.g., 5, I need both roundup_pow_of_two() > > > > > to bump it to 8, and clamp() to enforce that it's between 2 and 256. > > > > > > > > > > Unless you mean I should simply write it like: > > > > > > > > > > div = clamp(roundup_pow_of_two(div), 2U, 256U); > > > > > > > > > > ... as a single line? > > > > > > > > Yes, that's what I meant. > > > > > > Turns out, clamp really hates being passed roundup_pow_of_two() > > > directly (see below). I think it's probably better if we leave > > > them as-is, to avoid going the explicit cast route which Geert > > > recommended against. > > > > I see, then ignore my comment on this matter in v9. > > Perhaps add a comment in the code explaining that roundup_pow_of_two() > > may not be unified with clamp()? > > I worry that commenting on why things are not done some other way at > that location would detract from the legibility of the code itself. > > Perhaps we could use a cast after all, and write it out like this: > > div = clamp((u32)roundup_pow_of_two(div), 2U, 256U); > > which compiles fine without any warnings, accomplishes your "do it in > a single line" desired behavior, and doesn't require me commenting on > which linux library functions do or don't work well with others... :) We may survive without comment, it's not a big deal. > Geert, what do you think? -- With Best Regards, Andy Shevchenko ^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2022-01-09 11:37 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
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2022-01-07 23:34 [PATCH v8 0/3] mmc: Add LiteSDCard mmc driver Gabriel Somlo
2022-01-07 23:34 ` [PATCH v8 1/3] MAINTAINERS: co-maintain LiteX platform Gabriel Somlo
2022-01-07 23:34 ` [PATCH v8 2/3] dt-bindings: mmc: Add bindings for LiteSDCard Gabriel Somlo
2022-01-07 23:34 ` [PATCH v8 3/3] mmc: Add driver for LiteX's LiteSDCard interface Gabriel Somlo
[not found] ` <CAHp75VcHnHpX1=ojmFnujqkf55aS1ePiVW4kKydTJQe=dXbwbQ@mail.gmail.com>
2022-01-08 1:57 ` Gabriel L. Somlo
2022-01-08 2:31 ` Gabriel L. Somlo
2022-01-08 11:29 ` Andy Shevchenko
2022-01-08 11:26 ` Andy Shevchenko
2022-01-08 13:20 ` Gabriel L. Somlo
2022-01-08 17:47 ` Andy Shevchenko
2022-01-08 23:51 ` Gabriel L. Somlo
2022-01-09 11:36 ` Andy Shevchenko
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