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@xxxxxxxxx> 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@xxxxxxxxxxxx> > > Signed-off-by: Kamil Rakoczy <krakoczy@xxxxxxxxxxxx> > > Co-developed-by: Maciej Dudek <mdudek@xxxxxxxxxxxxxxxxxxxxxxxx> > > Signed-off-by: Maciej Dudek <mdudek@xxxxxxxxxxxxxxxxxxxxxxxx> > > Co-developed-by: Paul Mackerras <paulus@xxxxxxxxxx> > > Signed-off-by: Paul Mackerras <paulus@xxxxxxxxxx> > > Signed-off-by: Gabriel Somlo <gsomlo@xxxxxxxxx> > > Reviewed-by: Joel Stanley <joel@xxxxxxxxx> > > --- > > > > 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@xxxxxxxxxxxx> > > + * Copyright (C) 2019-2020 Kamil Rakoczy <krakoczy@xxxxxxxxxxxx> > > + * Copyright (C) 2019-2020 Maciej Dudek <mdudek@xxxxxxxxxxxxxxxxxxxxxxxx> > > + * Copyright (C) 2020 Paul Mackerras <paulus@xxxxxxxxxx> > > + * Copyright (C) 2020-2021 Gabriel Somlo <gsomlo@xxxxxxxxx> > > + */ > > + > > +#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@xxxxxxxxxxxx>"); > > +MODULE_AUTHOR("Kamil Rakoczy <krakoczy@xxxxxxxxxxxx>"); > > +MODULE_AUTHOR("Maciej Dudek <mdudek@xxxxxxxxxxxxxxxxxxxxxxxx>"); > > +MODULE_AUTHOR("Paul Mackerras <paulus@xxxxxxxxxx>"); > > +MODULE_AUTHOR("Gabriel Somlo <gsomlo@xxxxxxxxx>"); > > +MODULE_LICENSE("GPL v2"); > > -- > > 2.31.1 > > > > > > > > > > -- > > With Best Regards, > > Andy Shevchenko > > > >
