@@ -1093,3 +1093,14 @@ config MMC_OWL
config MMC_SDHCI_EXTERNAL_DMA
bool
+
+config MMC_LITEX
+ tristate "LiteX MMC Host Controller support"
+ depends on ((PPC_MICROWATT || LITEX) && OF && HAVE_CLK) || 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.
+
+ If unsure, say N.
@@ -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
new file mode 100644
@@ -0,0 +1,663 @@
+// 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) 2020-2022 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/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;
+
+ 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);
+ irqreturn_t ret = IRQ_NONE;
+
+ /* 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));
+ ret = IRQ_HANDLED;
+ }
+
+ /* 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);
+ ret = IRQ_HANDLED;
+ }
+
+ return ret;
+}
+
+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 platform_device *pdev,
+ struct litex_mmc_host *host)
+{
+ struct device *dev = mmc_dev(host->mmc);
+ int ret;
+
+ ret = platform_get_irq_optional(pdev, 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(pdev, "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;
+
+ /* 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(pdev, 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);
+
+ ret = mmc_add_host(mmc);
+ if (ret)
+ return ret;
+
+ dev_info(dev, "LiteX MMC controller initialized.\n");
+
+ return 0;
+}
+
+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@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");