On Sun, Jan 9, 2022 at 4:56 PM 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! LGTM, thanks! FWIW, Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> One thing that may be improved later is the interrupt handler. I don't think it's correct to return IRQ_HANDLED in case there was no CMD or CD event, but I don't know the hardware either. > 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 v10: > drivers/mmc/host/litex_mmc.c: > - group `linux/mmc/*` includes by themselves > - clean-up of `return` style (multiple locations throughout source) > - create `mmc_free_host()` wrapper for use with > `devm_add_action_or_reset()` > - use GFP_KERNEL with `dmam_alloc_coherent()` > > >New in v9: > >drivers/mmc/host/Kconfig: > > - fix OF dependency > >drivers/mmc/host/litex_mmc.c: > > - remove `linux/of.h` include, no longer needed since dropping > > `of_match_ptr()` > > - add `linux/mod_devicetable.h` include > > - use devm_action_or_reset() to devm-ify mmc_alloc_host(), and obviate > > the need to call mmc_free_host() explicitly during either probe() > > error path or during remove() > > > >>New in v8: > >> - 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 | 9 + > drivers/mmc/host/Makefile | 1 + > drivers/mmc/host/litex_mmc.c | 655 +++++++++++++++++++++++++++++++++++ > 3 files changed, 665 insertions(+) > create mode 100644 drivers/mmc/host/litex_mmc.c > > diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig > index 5af8494c31b5..8f661f52b502 100644 > --- a/drivers/mmc/host/Kconfig > +++ b/drivers/mmc/host/Kconfig > @@ -1093,3 +1093,12 @@ config MMC_OWL > > config MMC_SDHCI_EXTERNAL_DMA > bool > + > +config MMC_LITEX > + tristate "LiteX MMC Host Controller support" > + depends on ((PPC_MICROWATT || LITEX) && OF) || 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..db1858e343c7 > --- /dev/null > +++ b/drivers/mmc/host/litex_mmc.c > @@ -0,0 +1,655 @@ > +// 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/mod_devicetable.h> > +#include <linux/module.h> > +#include <linux/platform_device.h> > + > +#include <linux/mmc/host.h> > +#include <linux/mmc/mmc.h> > +#include <linux/mmc/sd.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); > + if (ret) > + return ret; > + > + /* Ensure bus width will be set (again) upon card (re)insertion */ > + host->is_bus_width_set = false; > + > + return 0; > +} > + > +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 void litex_mmc_free_host_wrapper(void *mmc) > +{ > + mmc_free_host(mmc); > +} > + > +static int litex_mmc_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + 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), dev); > + if (!mmc) > + return -ENOMEM; > + > + ret = devm_add_action_or_reset(dev, litex_mmc_free_host_wrapper, mmc); > + if (ret) > + return dev_err_probe(dev, ret, > + "Can't register mmc_free_host action\n"); > + > + host = mmc_priv(mmc); > + host->mmc = mmc; > + host->dev = pdev; > + > + /* Initialize clock source */ > + clk = devm_clk_get(dev, NULL); > + if (IS_ERR(clk)) > + return dev_err_probe(dev, PTR_ERR(clk), "can't get clock\n"); > + 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(dev, DMA_BIT_MASK(64)); > + if (ret) > + return ret; > + > + host->buf_size = mmc->max_req_size * 2; > + host->buffer = dmam_alloc_coherent(dev, host->buf_size, > + &host->dma, GFP_KERNEL); > + if (host->buffer == NULL) > + return -ENOMEM; > + > + host->sdphy = devm_platform_ioremap_resource_byname(pdev, "phy"); > + if (IS_ERR(host->sdphy)) > + return PTR_ERR(host->sdphy); > + > + host->sdcore = devm_platform_ioremap_resource_byname(pdev, "core"); > + if (IS_ERR(host->sdcore)) > + return PTR_ERR(host->sdcore); > + > + host->sdreader = devm_platform_ioremap_resource_byname(pdev, "reader"); > + if (IS_ERR(host->sdreader)) > + return PTR_ERR(host->sdreader); > + > + host->sdwriter = devm_platform_ioremap_resource_byname(pdev, "writer"); > + if (IS_ERR(host->sdwriter)) > + return PTR_ERR(host->sdwriter); > + > + /* 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) > + return ret; > + > + /* 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) > + return ret; > + > + /* 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); > + > + return mmc_add_host(mmc); > +} > + > +static int litex_mmc_remove(struct platform_device *pdev) > +{ > + struct litex_mmc_host *host = platform_get_drvdata(pdev); > + > + mmc_remove_host(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
