]> git.proxmox.com Git - mirror_ubuntu-hirsute-kernel.git/commitdiff
mmc: add new Alcor Micro Cardreader SD/MMC driver
authorOleksij Rempel <linux@rempel-privat.de>
Sun, 2 Dec 2018 10:30:46 +0000 (11:30 +0100)
committerUlf Hansson <ulf.hansson@linaro.org>
Mon, 17 Dec 2018 07:26:24 +0000 (08:26 +0100)
This driver provides support for Alcor Micro AU6601 and AU6621
SD/MMC controller.

Signed-off-by: Oleksij Rempel <linux@rempel-privat.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
drivers/mmc/host/Kconfig
drivers/mmc/host/Makefile
drivers/mmc/host/alcor.c [new file with mode: 0644]

index 720311ece714d6891e8ccd46a3d06ad6a55fda6b..5fa580cec8318233c0337f4214e7a8456d71215d 100644 (file)
@@ -441,6 +441,13 @@ config MMC_WBSD
 
          If unsure, say N.
 
+config MMC_ALCOR
+       tristate "Alcor Micro/Alcor Link SD/MMC controller"
+       depends on MISC_ALCOR_PCI
+       help
+         Say Y here to include driver code to support SD/MMC card interface
+         of Alcor Micro PCI-E card reader
+
 config MMC_AU1X
        tristate "Alchemy AU1XX0 MMC Card Interface support"
        depends on MIPS_ALCHEMY
index 720d3777709838191fed6e7f49b837a5aee07328..0a38e654a2ce554bf64cd954036b80fb36c5de57 100644 (file)
@@ -24,6 +24,7 @@ obj-$(CONFIG_MMC_SDHCI_F_SDH30)       += sdhci_f_sdh30.o
 obj-$(CONFIG_MMC_SDHCI_SPEAR)  += sdhci-spear.o
 obj-$(CONFIG_MMC_WBSD)         += wbsd.o
 obj-$(CONFIG_MMC_AU1X)         += au1xmmc.o
+obj-$(CONFIG_MMC_ALCOR)        += alcor.o
 obj-$(CONFIG_MMC_MTK)          += mtk-sd.o
 obj-$(CONFIG_MMC_OMAP)         += omap.o
 obj-$(CONFIG_MMC_OMAP_HS)      += omap_hsmmc.o
diff --git a/drivers/mmc/host/alcor.c b/drivers/mmc/host/alcor.c
new file mode 100644 (file)
index 0000000..f729a64
--- /dev/null
@@ -0,0 +1,1165 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018 Oleksij Rempel <linux@rempel-privat.de>
+ *
+ * Driver for Alcor Micro AU6601 and AU6621 controllers
+ */
+
+/* Note: this driver was created without any documentation. Based
+ * on sniffing, testing and in some cases mimic of original driver.
+ * As soon as some one with documentation or more experience in SD/MMC, or
+ * reverse engineering then me, please review this driver and question every
+ * thing what I did. 2018 Oleksij Rempel <linux@rempel-privat.de>
+ */
+
+#include <linux/delay.h>
+#include <linux/pci.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/pm.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+
+#include <linux/mmc/host.h>
+#include <linux/mmc/mmc.h>
+
+#include <linux/alcor_pci.h>
+
+enum alcor_cookie {
+       COOKIE_UNMAPPED,
+       COOKIE_PRE_MAPPED,
+       COOKIE_MAPPED,
+};
+
+struct alcor_pll_conf {
+       unsigned int clk_src_freq;
+       unsigned int clk_src_reg;
+       unsigned int min_div;
+       unsigned int max_div;
+};
+
+struct alcor_sdmmc_host {
+       struct  device *dev;
+       struct alcor_pci_priv *alcor_pci;
+
+       struct mmc_host *mmc;
+       struct mmc_request *mrq;
+       struct mmc_command *cmd;
+       struct mmc_data *data;
+       unsigned int dma_on:1;
+       unsigned int early_data:1;
+
+       struct mutex cmd_mutex;
+
+       struct delayed_work timeout_work;
+
+       struct sg_mapping_iter sg_miter;        /* SG state for PIO */
+       struct scatterlist *sg;
+       unsigned int blocks;            /* remaining PIO blocks */
+       int sg_count;
+
+       u32                     irq_status_sd;
+       unsigned char           cur_power_mode;
+};
+
+static const struct alcor_pll_conf alcor_pll_cfg[] = {
+       /* MHZ,         CLK src,                max div, min div */
+       { 31250000,     AU6601_CLK_31_25_MHZ,   1,      511},
+       { 48000000,     AU6601_CLK_48_MHZ,      1,      511},
+       {125000000,     AU6601_CLK_125_MHZ,     1,      511},
+       {384000000,     AU6601_CLK_384_MHZ,     1,      511},
+};
+
+static inline void alcor_rmw8(struct alcor_sdmmc_host *host, unsigned int addr,
+                              u8 clear, u8 set)
+{
+       struct alcor_pci_priv *priv = host->alcor_pci;
+       u32 var;
+
+       var = alcor_read8(priv, addr);
+       var &= ~clear;
+       var |= set;
+       alcor_write8(priv, var, addr);
+}
+
+/* As soon as irqs are masked, some status updates may be missed.
+ * Use this with care.
+ */
+static inline void alcor_mask_sd_irqs(struct alcor_sdmmc_host *host)
+{
+       struct alcor_pci_priv *priv = host->alcor_pci;
+
+       alcor_write32(priv, 0, AU6601_REG_INT_ENABLE);
+}
+
+static inline void alcor_unmask_sd_irqs(struct alcor_sdmmc_host *host)
+{
+       struct alcor_pci_priv *priv = host->alcor_pci;
+
+       alcor_write32(priv, AU6601_INT_CMD_MASK | AU6601_INT_DATA_MASK |
+                 AU6601_INT_CARD_INSERT | AU6601_INT_CARD_REMOVE |
+                 AU6601_INT_OVER_CURRENT_ERR,
+                 AU6601_REG_INT_ENABLE);
+}
+
+static void alcor_reset(struct alcor_sdmmc_host *host, u8 val)
+{
+       struct alcor_pci_priv *priv = host->alcor_pci;
+       int i;
+
+       alcor_write8(priv, val | AU6601_BUF_CTRL_RESET,
+                     AU6601_REG_SW_RESET);
+       for (i = 0; i < 100; i++) {
+               if (!(alcor_read8(priv, AU6601_REG_SW_RESET) & val))
+                       return;
+               udelay(50);
+       }
+       dev_err(host->dev, "%s: timeout\n", __func__);
+}
+
+static void alcor_data_set_dma(struct alcor_sdmmc_host *host)
+{
+       struct alcor_pci_priv *priv = host->alcor_pci;
+       u32 addr, len;
+
+       if (!host->sg_count)
+               return;
+
+       if (!host->sg) {
+               dev_err(host->dev, "have blocks, but no SG\n");
+               return;
+       }
+
+       if (!sg_dma_len(host->sg)) {
+               dev_err(host->dev, "DMA SG len == 0\n");
+               return;
+       }
+
+
+       addr = (u32)sg_dma_address(host->sg);
+       len = sg_dma_len(host->sg);
+
+       alcor_write32(priv, addr, AU6601_REG_SDMA_ADDR);
+       host->sg = sg_next(host->sg);
+       host->sg_count--;
+}
+
+static void alcor_trigger_data_transfer(struct alcor_sdmmc_host *host,
+                                       bool early)
+{
+       struct alcor_pci_priv *priv = host->alcor_pci;
+       struct mmc_data *data = host->data;
+       u8 ctrl = 0;
+
+       if (data->flags & MMC_DATA_WRITE)
+               ctrl |= AU6601_DATA_WRITE;
+
+       if (data->host_cookie == COOKIE_MAPPED) {
+               if (host->early_data) {
+                       host->early_data = false;
+                       return;
+               }
+
+               host->early_data = early;
+
+               alcor_data_set_dma(host);
+               ctrl |= AU6601_DATA_DMA_MODE;
+               host->dma_on = 1;
+               alcor_write32(priv, data->sg_count * 0x1000,
+                              AU6601_REG_BLOCK_SIZE);
+       } else {
+               alcor_write32(priv, data->blksz, AU6601_REG_BLOCK_SIZE);
+       }
+
+       alcor_write8(priv, ctrl | AU6601_DATA_START_XFER,
+                     AU6601_DATA_XFER_CTRL);
+}
+
+static void alcor_trf_block_pio(struct alcor_sdmmc_host *host, bool read)
+{
+       struct alcor_pci_priv *priv = host->alcor_pci;
+       size_t blksize, len;
+       u8 *buf;
+
+       if (!host->blocks)
+               return;
+
+       if (host->dma_on) {
+               dev_err(host->dev, "configured DMA but got PIO request.\n");
+               return;
+       }
+
+       if (!!(host->data->flags & MMC_DATA_READ) != read) {
+               dev_err(host->dev, "got unexpected direction %i != %i\n",
+                       !!(host->data->flags & MMC_DATA_READ), read);
+       }
+
+       if (!sg_miter_next(&host->sg_miter))
+               return;
+
+       blksize = host->data->blksz;
+       len = min(host->sg_miter.length, blksize);
+
+       dev_dbg(host->dev, "PIO, %s block size: 0x%zx\n",
+               read ? "read" : "write", blksize);
+
+       host->sg_miter.consumed = len;
+       host->blocks--;
+
+       buf = host->sg_miter.addr;
+
+       if (read)
+               ioread32_rep(priv->iobase + AU6601_REG_BUFFER, buf, len >> 2);
+       else
+               iowrite32_rep(priv->iobase + AU6601_REG_BUFFER, buf, len >> 2);
+
+       sg_miter_stop(&host->sg_miter);
+}
+
+static void alcor_prepare_sg_miter(struct alcor_sdmmc_host *host)
+{
+       unsigned int flags = SG_MITER_ATOMIC;
+       struct mmc_data *data = host->data;
+
+       if (data->flags & MMC_DATA_READ)
+               flags |= SG_MITER_TO_SG;
+       else
+               flags |= SG_MITER_FROM_SG;
+       sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
+}
+
+static void alcor_prepare_data(struct alcor_sdmmc_host *host,
+                              struct mmc_command *cmd)
+{
+       struct mmc_data *data = cmd->data;
+
+       if (!data)
+               return;
+
+
+       host->data = data;
+       host->data->bytes_xfered = 0;
+       host->blocks = data->blocks;
+       host->sg = data->sg;
+       host->sg_count = data->sg_count;
+       dev_dbg(host->dev, "prepare DATA: sg %i, blocks: %i\n",
+                       host->sg_count, host->blocks);
+
+       if (data->host_cookie != COOKIE_MAPPED)
+               alcor_prepare_sg_miter(host);
+
+       alcor_trigger_data_transfer(host, true);
+}
+
+static void alcor_send_cmd(struct alcor_sdmmc_host *host,
+                          struct mmc_command *cmd, bool set_timeout)
+{
+       struct alcor_pci_priv *priv = host->alcor_pci;
+       unsigned long timeout = 0;
+       u8 ctrl = 0;
+
+       host->cmd = cmd;
+       alcor_prepare_data(host, cmd);
+
+       dev_dbg(host->dev, "send CMD. opcode: 0x%02x, arg; 0x%08x\n",
+               cmd->opcode, cmd->arg);
+       alcor_write8(priv, cmd->opcode | 0x40, AU6601_REG_CMD_OPCODE);
+       alcor_write32be(priv, cmd->arg, AU6601_REG_CMD_ARG);
+
+       switch (mmc_resp_type(cmd)) {
+       case MMC_RSP_NONE:
+               ctrl = AU6601_CMD_NO_RESP;
+               break;
+       case MMC_RSP_R1:
+               ctrl = AU6601_CMD_6_BYTE_CRC;
+               break;
+       case MMC_RSP_R1B:
+               ctrl = AU6601_CMD_6_BYTE_CRC | AU6601_CMD_STOP_WAIT_RDY;
+               break;
+       case MMC_RSP_R2:
+               ctrl = AU6601_CMD_17_BYTE_CRC;
+               break;
+       case MMC_RSP_R3:
+               ctrl = AU6601_CMD_6_BYTE_WO_CRC;
+               break;
+       default:
+               dev_err(host->dev, "%s: cmd->flag (0x%02x) is not valid\n",
+                       mmc_hostname(host->mmc), mmc_resp_type(cmd));
+               break;
+       }
+
+       if (set_timeout) {
+               if (!cmd->data && cmd->busy_timeout)
+                       timeout = cmd->busy_timeout;
+               else
+                       timeout = 10000;
+
+               schedule_delayed_work(&host->timeout_work,
+                                     msecs_to_jiffies(timeout));
+       }
+
+       dev_dbg(host->dev, "xfer ctrl: 0x%02x; timeout: %lu\n", ctrl, timeout);
+       alcor_write8(priv, ctrl | AU6601_CMD_START_XFER,
+                                AU6601_CMD_XFER_CTRL);
+}
+
+static void alcor_request_complete(struct alcor_sdmmc_host *host,
+                                  bool cancel_timeout)
+{
+       struct mmc_request *mrq;
+
+       /*
+        * If this work gets rescheduled while running, it will
+        * be run again afterwards but without any active request.
+        */
+       if (!host->mrq)
+               return;
+
+       if (cancel_timeout)
+               cancel_delayed_work(&host->timeout_work);
+
+       mrq = host->mrq;
+
+       host->mrq = NULL;
+       host->cmd = NULL;
+       host->data = NULL;
+       host->dma_on = 0;
+
+       mmc_request_done(host->mmc, mrq);
+}
+
+static void alcor_finish_data(struct alcor_sdmmc_host *host)
+{
+       struct mmc_data *data;
+
+       data = host->data;
+       host->data = NULL;
+       host->dma_on = 0;
+
+       /*
+        * The specification states that the block count register must
+        * be updated, but it does not specify at what point in the
+        * data flow. That makes the register entirely useless to read
+        * back so we have to assume that nothing made it to the card
+        * in the event of an error.
+        */
+       if (data->error)
+               data->bytes_xfered = 0;
+       else
+               data->bytes_xfered = data->blksz * data->blocks;
+
+       /*
+        * Need to send CMD12 if -
+        * a) open-ended multiblock transfer (no CMD23)
+        * b) error in multiblock transfer
+        */
+       if (data->stop &&
+           (data->error ||
+            !host->mrq->sbc)) {
+
+               /*
+                * The controller needs a reset of internal state machines
+                * upon error conditions.
+                */
+               if (data->error)
+                       alcor_reset(host, AU6601_RESET_CMD | AU6601_RESET_DATA);
+
+               alcor_unmask_sd_irqs(host);
+               alcor_send_cmd(host, data->stop, false);
+               return;
+       }
+
+       alcor_request_complete(host, 1);
+}
+
+static void alcor_err_irq(struct alcor_sdmmc_host *host, u32 intmask)
+{
+       dev_dbg(host->dev, "ERR IRQ %x\n", intmask);
+
+       if (host->cmd) {
+               if (intmask & AU6601_INT_CMD_TIMEOUT_ERR)
+                       host->cmd->error = -ETIMEDOUT;
+               else
+                       host->cmd->error = -EILSEQ;
+       }
+
+       if (host->data) {
+               if (intmask & AU6601_INT_DATA_TIMEOUT_ERR)
+                       host->data->error = -ETIMEDOUT;
+               else
+                       host->data->error = -EILSEQ;
+
+               host->data->bytes_xfered = 0;
+       }
+
+       alcor_reset(host, AU6601_RESET_CMD | AU6601_RESET_DATA);
+       alcor_request_complete(host, 1);
+}
+
+static int alcor_cmd_irq_done(struct alcor_sdmmc_host *host, u32 intmask)
+{
+       struct alcor_pci_priv *priv = host->alcor_pci;
+
+       intmask &= AU6601_INT_CMD_END;
+
+       if (!intmask)
+               return true;
+
+       /* got CMD_END but no CMD is in progress, wake thread an process the
+        * error
+        */
+       if (!host->cmd)
+               return false;
+
+       if (host->cmd->flags & MMC_RSP_PRESENT) {
+               struct mmc_command *cmd = host->cmd;
+
+               cmd->resp[0] = alcor_read32be(priv, AU6601_REG_CMD_RSP0);
+               dev_dbg(host->dev, "RSP0: 0x%04x\n", cmd->resp[0]);
+               if (host->cmd->flags & MMC_RSP_136) {
+                       cmd->resp[1] =
+                               alcor_read32be(priv, AU6601_REG_CMD_RSP1);
+                       cmd->resp[2] =
+                               alcor_read32be(priv, AU6601_REG_CMD_RSP2);
+                       cmd->resp[3] =
+                               alcor_read32be(priv, AU6601_REG_CMD_RSP3);
+                       dev_dbg(host->dev, "RSP1,2,3: 0x%04x 0x%04x 0x%04x\n",
+                               cmd->resp[1], cmd->resp[2], cmd->resp[3]);
+               }
+
+       }
+
+       host->cmd->error = 0;
+
+       /* Processed actual command. */
+       if (!host->data)
+               return false;
+
+       alcor_trigger_data_transfer(host, false);
+       host->cmd = NULL;
+       return true;
+}
+
+static void alcor_cmd_irq_thread(struct alcor_sdmmc_host *host, u32 intmask)
+{
+       intmask &= AU6601_INT_CMD_END;
+
+       if (!intmask)
+               return;
+
+       if (!host->cmd && intmask & AU6601_INT_CMD_END) {
+               dev_dbg(host->dev, "Got command interrupt 0x%08x even though no command operation was in progress.\n",
+                       intmask);
+       }
+
+       /* Processed actual command. */
+       if (!host->data)
+               alcor_request_complete(host, 1);
+       else
+               alcor_trigger_data_transfer(host, false);
+       host->cmd = NULL;
+}
+
+static int alcor_data_irq_done(struct alcor_sdmmc_host *host, u32 intmask)
+{
+       u32 tmp;
+
+       intmask &= AU6601_INT_DATA_MASK;
+
+       /* nothing here to do */
+       if (!intmask)
+               return 1;
+
+       /* we was too fast and got DATA_END after it was processed?
+        * lets ignore it for now.
+        */
+       if (!host->data && intmask == AU6601_INT_DATA_END)
+               return 1;
+
+       /* looks like an error, so lets handle it. */
+       if (!host->data)
+               return 0;
+
+       tmp = intmask & (AU6601_INT_READ_BUF_RDY | AU6601_INT_WRITE_BUF_RDY
+                        | AU6601_INT_DMA_END);
+       switch (tmp) {
+       case 0:
+               break;
+       case AU6601_INT_READ_BUF_RDY:
+               alcor_trf_block_pio(host, true);
+               if (!host->blocks)
+                       break;
+               alcor_trigger_data_transfer(host, false);
+               return 1;
+       case AU6601_INT_WRITE_BUF_RDY:
+               alcor_trf_block_pio(host, false);
+               if (!host->blocks)
+                       break;
+               alcor_trigger_data_transfer(host, false);
+               return 1;
+       case AU6601_INT_DMA_END:
+               if (!host->sg_count)
+                       break;
+
+               alcor_data_set_dma(host);
+               break;
+       default:
+               dev_err(host->dev, "Got READ_BUF_RDY and WRITE_BUF_RDY at same time\n");
+               break;
+       }
+
+       if (intmask & AU6601_INT_DATA_END)
+               return 0;
+
+       return 1;
+}
+
+static void alcor_data_irq_thread(struct alcor_sdmmc_host *host, u32 intmask)
+{
+       intmask &= AU6601_INT_DATA_MASK;
+
+       if (!intmask)
+               return;
+
+       if (!host->data) {
+               dev_dbg(host->dev, "Got data interrupt 0x%08x even though no data operation was in progress.\n",
+                       intmask);
+               alcor_reset(host, AU6601_RESET_DATA);
+               return;
+       }
+
+       if (alcor_data_irq_done(host, intmask))
+               return;
+
+       if ((intmask & AU6601_INT_DATA_END) || !host->blocks ||
+           (host->dma_on && !host->sg_count))
+               alcor_finish_data(host);
+}
+
+static void alcor_cd_irq(struct alcor_sdmmc_host *host, u32 intmask)
+{
+       dev_dbg(host->dev, "card %s\n",
+               intmask & AU6601_INT_CARD_REMOVE ? "removed" : "inserted");
+
+       if (host->mrq) {
+               dev_dbg(host->dev, "cancel all pending tasks.\n");
+
+               if (host->data)
+                       host->data->error = -ENOMEDIUM;
+
+               if (host->cmd)
+                       host->cmd->error = -ENOMEDIUM;
+               else
+                       host->mrq->cmd->error = -ENOMEDIUM;
+
+               alcor_request_complete(host, 1);
+       }
+
+       mmc_detect_change(host->mmc, msecs_to_jiffies(1));
+}
+
+static irqreturn_t alcor_irq_thread(int irq, void *d)
+{
+       struct alcor_sdmmc_host *host = d;
+       irqreturn_t ret = IRQ_HANDLED;
+       u32 intmask, tmp;
+
+       mutex_lock(&host->cmd_mutex);
+
+       intmask = host->irq_status_sd;
+
+       /* some thing bad */
+       if (unlikely(!intmask || AU6601_INT_ALL_MASK == intmask)) {
+               dev_dbg(host->dev, "unexpected IRQ: 0x%04x\n", intmask);
+               ret = IRQ_NONE;
+               goto exit;
+       }
+
+       tmp = intmask & (AU6601_INT_CMD_MASK | AU6601_INT_DATA_MASK);
+       if (tmp) {
+               if (tmp & AU6601_INT_ERROR_MASK)
+                       alcor_err_irq(host, tmp);
+               else {
+                       alcor_cmd_irq_thread(host, tmp);
+                       alcor_data_irq_thread(host, tmp);
+               }
+               intmask &= ~(AU6601_INT_CMD_MASK | AU6601_INT_DATA_MASK);
+       }
+
+       if (intmask & (AU6601_INT_CARD_INSERT | AU6601_INT_CARD_REMOVE)) {
+               alcor_cd_irq(host, intmask);
+               intmask &= ~(AU6601_INT_CARD_INSERT | AU6601_INT_CARD_REMOVE);
+       }
+
+       if (intmask & AU6601_INT_OVER_CURRENT_ERR) {
+               dev_warn(host->dev,
+                        "warning: over current detected!\n");
+               intmask &= ~AU6601_INT_OVER_CURRENT_ERR;
+       }
+
+       if (intmask)
+               dev_dbg(host->dev, "got not handled IRQ: 0x%04x\n", intmask);
+
+exit:
+       mutex_unlock(&host->cmd_mutex);
+       alcor_unmask_sd_irqs(host);
+       return ret;
+}
+
+
+static irqreturn_t alcor_irq(int irq, void *d)
+{
+       struct alcor_sdmmc_host *host = d;
+       struct alcor_pci_priv *priv = host->alcor_pci;
+       u32 status, tmp;
+       irqreturn_t ret;
+       int cmd_done, data_done;
+
+       status = alcor_read32(priv, AU6601_REG_INT_STATUS);
+       if (!status)
+               return IRQ_NONE;
+
+       alcor_write32(priv, status, AU6601_REG_INT_STATUS);
+
+       tmp = status & (AU6601_INT_READ_BUF_RDY | AU6601_INT_WRITE_BUF_RDY
+                       | AU6601_INT_DATA_END | AU6601_INT_DMA_END
+                       | AU6601_INT_CMD_END);
+       if (tmp == status) {
+               cmd_done = alcor_cmd_irq_done(host, tmp);
+               data_done = alcor_data_irq_done(host, tmp);
+               /* use fast path for simple tasks */
+               if (cmd_done && data_done) {
+                       ret = IRQ_HANDLED;
+                       goto alcor_irq_done;
+               }
+       }
+
+       host->irq_status_sd = status;
+       ret = IRQ_WAKE_THREAD;
+       alcor_mask_sd_irqs(host);
+alcor_irq_done:
+       return ret;
+}
+
+static void alcor_set_clock(struct alcor_sdmmc_host *host, unsigned int clock)
+{
+       struct alcor_pci_priv *priv = host->alcor_pci;
+       unsigned int clock_out = 0;
+       int i, diff = 0x7fffffff, tmp_clock = 0;
+       u16 clk_src = 0;
+       u8 clk_div = 0;
+
+       if (clock == 0) {
+               alcor_write16(priv, 0, AU6601_CLK_SELECT);
+               return;
+       }
+
+       for (i = 0; i < ARRAY_SIZE(alcor_pll_cfg); i++) {
+               unsigned int tmp_div, tmp_diff;
+               const struct alcor_pll_conf *cfg = &alcor_pll_cfg[i];
+
+               tmp_div = DIV_ROUND_UP(cfg->clk_src_freq, clock);
+               if (cfg->min_div > tmp_div || tmp_div > cfg->max_div)
+                       continue;
+
+               tmp_clock = DIV_ROUND_UP(cfg->clk_src_freq, tmp_div);
+               tmp_diff = abs(clock - tmp_clock);
+
+               if (tmp_diff >= 0 && tmp_diff < diff) {
+                       diff = tmp_diff;
+                       clk_src = cfg->clk_src_reg;
+                       clk_div = tmp_div;
+                       clock_out = tmp_clock;
+               }
+       }
+
+       clk_src |= ((clk_div - 1) << 8);
+       clk_src |= AU6601_CLK_ENABLE;
+
+       dev_dbg(host->dev, "set freq %d cal freq %d, use div %d, mod %x\n",
+                       clock, tmp_clock, clk_div, clk_src);
+
+       alcor_write16(priv, clk_src, AU6601_CLK_SELECT);
+
+}
+
+static void alcor_set_timing(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+       struct alcor_sdmmc_host *host = mmc_priv(mmc);
+
+       if (ios->timing == MMC_TIMING_LEGACY) {
+               alcor_rmw8(host, AU6601_CLK_DELAY,
+                           AU6601_CLK_POSITIVE_EDGE_ALL, 0);
+       } else {
+               alcor_rmw8(host, AU6601_CLK_DELAY,
+                           0, AU6601_CLK_POSITIVE_EDGE_ALL);
+       }
+}
+
+static void alcor_set_bus_width(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+       struct alcor_sdmmc_host *host = mmc_priv(mmc);
+       struct alcor_pci_priv *priv = host->alcor_pci;
+
+       if (ios->bus_width == MMC_BUS_WIDTH_1) {
+               alcor_write8(priv, 0, AU6601_REG_BUS_CTRL);
+       } else if (ios->bus_width == MMC_BUS_WIDTH_4) {
+               alcor_write8(priv, AU6601_BUS_WIDTH_4BIT,
+                             AU6601_REG_BUS_CTRL);
+       } else
+               dev_err(host->dev, "Unknown BUS mode\n");
+
+}
+
+static int alcor_card_busy(struct mmc_host *mmc)
+{
+       struct alcor_sdmmc_host *host = mmc_priv(mmc);
+       struct alcor_pci_priv *priv = host->alcor_pci;
+       u8 status;
+
+       /* Check whether dat[0:3] low */
+       status = alcor_read8(priv, AU6601_DATA_PIN_STATE);
+
+       return !(status & AU6601_BUS_STAT_DAT_MASK);
+}
+
+static int alcor_get_cd(struct mmc_host *mmc)
+{
+       struct alcor_sdmmc_host *host = mmc_priv(mmc);
+       struct alcor_pci_priv *priv = host->alcor_pci;
+       u8 detect;
+
+       detect = alcor_read8(priv, AU6601_DETECT_STATUS)
+               & AU6601_DETECT_STATUS_M;
+       /* check if card is present then send command and data */
+       return (detect == AU6601_SD_DETECTED);
+}
+
+static int alcor_get_ro(struct mmc_host *mmc)
+{
+       struct alcor_sdmmc_host *host = mmc_priv(mmc);
+       struct alcor_pci_priv *priv = host->alcor_pci;
+       u8 status;
+
+       /* get write protect pin status */
+       status = alcor_read8(priv, AU6601_INTERFACE_MODE_CTRL);
+
+       return !!(status & AU6601_SD_CARD_WP);
+}
+
+static void alcor_request(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+       struct alcor_sdmmc_host *host = mmc_priv(mmc);
+
+       mutex_lock(&host->cmd_mutex);
+
+       host->mrq = mrq;
+
+       /* check if card is present then send command and data */
+       if (alcor_get_cd(mmc))
+               alcor_send_cmd(host, mrq->cmd, true);
+       else {
+               mrq->cmd->error = -ENOMEDIUM;
+               alcor_request_complete(host, 1);
+       }
+
+       mutex_unlock(&host->cmd_mutex);
+}
+
+static void alcor_pre_req(struct mmc_host *mmc,
+                          struct mmc_request *mrq)
+{
+       struct alcor_sdmmc_host *host = mmc_priv(mmc);
+       struct mmc_data *data = mrq->data;
+       struct mmc_command *cmd = mrq->cmd;
+       struct scatterlist *sg;
+       unsigned int i, sg_len;
+
+       if (!data || !cmd)
+               return;
+
+       data->host_cookie = COOKIE_UNMAPPED;
+
+       /* FIXME: looks like the DMA engine works only with CMD18 */
+       if (cmd->opcode != 18)
+               return;
+       /*
+        * We don't do DMA on "complex" transfers, i.e. with
+        * non-word-aligned buffers or lengths. Also, we don't bother
+        * with all the DMA setup overhead for short transfers.
+        */
+       if (data->blocks * data->blksz < AU6601_MAX_DMA_BLOCK_SIZE)
+               return;
+
+       if (data->blksz & 3)
+               return;
+
+       for_each_sg(data->sg, sg, data->sg_len, i) {
+               if (sg->length != AU6601_MAX_DMA_BLOCK_SIZE)
+                       return;
+       }
+
+       /* This data might be unmapped at this time */
+
+       sg_len = dma_map_sg(host->dev, data->sg, data->sg_len,
+                           mmc_get_dma_dir(data));
+       if (sg_len)
+               data->host_cookie = COOKIE_MAPPED;
+
+       data->sg_count = sg_len;
+}
+
+static void alcor_post_req(struct mmc_host *mmc,
+                           struct mmc_request *mrq,
+                           int err)
+{
+       struct alcor_sdmmc_host *host = mmc_priv(mmc);
+       struct mmc_data *data = mrq->data;
+
+       if (!data)
+               return;
+
+       if (data->host_cookie == COOKIE_MAPPED) {
+               dma_unmap_sg(host->dev,
+                            data->sg,
+                            data->sg_len,
+                            mmc_get_dma_dir(data));
+       }
+
+       data->host_cookie = COOKIE_UNMAPPED;
+}
+
+static void alcor_set_power_mode(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+       struct alcor_sdmmc_host *host = mmc_priv(mmc);
+       struct alcor_pci_priv *priv = host->alcor_pci;
+
+       switch (ios->power_mode) {
+       case MMC_POWER_OFF:
+               alcor_set_clock(host, ios->clock);
+               /* set all pins to input */
+               alcor_write8(priv, 0, AU6601_OUTPUT_ENABLE);
+               /* turn of VDD */
+               alcor_write8(priv, 0, AU6601_POWER_CONTROL);
+               break;
+       case MMC_POWER_UP:
+               break;
+       case MMC_POWER_ON:
+               /* This is most trickiest part. The order and timings of
+                * instructions seems to play important role. Any changes may
+                * confuse internal state engine if this HW.
+                * FIXME: If we will ever get access to documentation, then this
+                * part should be reviewed again.
+                */
+
+               /* enable SD card mode */
+               alcor_write8(priv, AU6601_SD_CARD,
+                             AU6601_ACTIVE_CTRL);
+               /* set signal voltage to 3.3V */
+               alcor_write8(priv, 0, AU6601_OPT);
+               /* no documentation about clk delay, for now just try to mimic
+                * original driver.
+                */
+               alcor_write8(priv, 0x20, AU6601_CLK_DELAY);
+               /* set BUS width to 1 bit */
+               alcor_write8(priv, 0, AU6601_REG_BUS_CTRL);
+               /* set CLK first time */
+               alcor_set_clock(host, ios->clock);
+               /* power on VDD */
+               alcor_write8(priv, AU6601_SD_CARD,
+                             AU6601_POWER_CONTROL);
+               /* wait until the CLK will get stable */
+               mdelay(20);
+               /* set CLK again, mimic original driver. */
+               alcor_set_clock(host, ios->clock);
+
+               /* enable output */
+               alcor_write8(priv, AU6601_SD_CARD,
+                             AU6601_OUTPUT_ENABLE);
+               /* The clk will not work on au6621. We need to trigger data
+                * transfer.
+                */
+               alcor_write8(priv, AU6601_DATA_WRITE,
+                             AU6601_DATA_XFER_CTRL);
+               /* configure timeout. Not clear what exactly it means. */
+               alcor_write8(priv, 0x7d, AU6601_TIME_OUT_CTRL);
+               mdelay(100);
+               break;
+       default:
+               dev_err(host->dev, "Unknown power parameter\n");
+       }
+}
+
+static void alcor_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+       struct alcor_sdmmc_host *host = mmc_priv(mmc);
+
+       mutex_lock(&host->cmd_mutex);
+
+       dev_dbg(host->dev, "set ios. bus width: %x, power mode: %x\n",
+               ios->bus_width, ios->power_mode);
+
+       if (ios->power_mode != host->cur_power_mode) {
+               alcor_set_power_mode(mmc, ios);
+               host->cur_power_mode = ios->power_mode;
+       } else {
+               alcor_set_timing(mmc, ios);
+               alcor_set_bus_width(mmc, ios);
+               alcor_set_clock(host, ios->clock);
+       }
+
+       mutex_unlock(&host->cmd_mutex);
+}
+
+static int alcor_signal_voltage_switch(struct mmc_host *mmc,
+                                      struct mmc_ios *ios)
+{
+       struct alcor_sdmmc_host *host = mmc_priv(mmc);
+
+       mutex_lock(&host->cmd_mutex);
+
+       switch (ios->signal_voltage) {
+       case MMC_SIGNAL_VOLTAGE_330:
+               alcor_rmw8(host, AU6601_OPT, AU6601_OPT_SD_18V, 0);
+               break;
+       case MMC_SIGNAL_VOLTAGE_180:
+               alcor_rmw8(host, AU6601_OPT, 0, AU6601_OPT_SD_18V);
+               break;
+       default:
+               /* No signal voltage switch required */
+               break;
+       }
+
+       mutex_unlock(&host->cmd_mutex);
+       return 0;
+}
+
+static const struct mmc_host_ops alcor_sdc_ops = {
+       .card_busy      = alcor_card_busy,
+       .get_cd         = alcor_get_cd,
+       .get_ro         = alcor_get_ro,
+       .post_req       = alcor_post_req,
+       .pre_req        = alcor_pre_req,
+       .request        = alcor_request,
+       .set_ios        = alcor_set_ios,
+       .start_signal_voltage_switch = alcor_signal_voltage_switch,
+};
+
+static void alcor_timeout_timer(struct work_struct *work)
+{
+       struct delayed_work *d = to_delayed_work(work);
+       struct alcor_sdmmc_host *host = container_of(d, struct alcor_sdmmc_host,
+                                               timeout_work);
+       mutex_lock(&host->cmd_mutex);
+
+       dev_dbg(host->dev, "triggered timeout\n");
+       if (host->mrq) {
+               dev_err(host->dev, "Timeout waiting for hardware interrupt.\n");
+
+               if (host->data) {
+                       host->data->error = -ETIMEDOUT;
+               } else {
+                       if (host->cmd)
+                               host->cmd->error = -ETIMEDOUT;
+                       else
+                               host->mrq->cmd->error = -ETIMEDOUT;
+               }
+
+               alcor_reset(host, AU6601_RESET_CMD | AU6601_RESET_DATA);
+               alcor_request_complete(host, 0);
+       }
+
+       mmiowb();
+       mutex_unlock(&host->cmd_mutex);
+}
+
+static void alcor_hw_init(struct alcor_sdmmc_host *host)
+{
+       struct alcor_pci_priv *priv = host->alcor_pci;
+       struct alcor_dev_cfg *cfg = priv->cfg;
+
+       /* FIXME: This part is a mimics HW init of original driver.
+        * If we will ever get access to documentation, then this part
+        * should be reviewed again.
+        */
+
+       /* reset command state engine */
+       alcor_reset(host, AU6601_RESET_CMD);
+
+       alcor_write8(priv, 0, AU6601_DMA_BOUNDARY);
+       /* enable sd card mode */
+       alcor_write8(priv, AU6601_SD_CARD, AU6601_ACTIVE_CTRL);
+
+       /* set BUS width to 1 bit */
+       alcor_write8(priv, 0, AU6601_REG_BUS_CTRL);
+
+       /* reset data state engine */
+       alcor_reset(host, AU6601_RESET_DATA);
+       /* Not sure if a voodoo with AU6601_DMA_BOUNDARY is really needed */
+       alcor_write8(priv, 0, AU6601_DMA_BOUNDARY);
+
+       alcor_write8(priv, 0, AU6601_INTERFACE_MODE_CTRL);
+       /* not clear what we are doing here. */
+       alcor_write8(priv, 0x44, AU6601_PAD_DRIVE0);
+       alcor_write8(priv, 0x44, AU6601_PAD_DRIVE1);
+       alcor_write8(priv, 0x00, AU6601_PAD_DRIVE2);
+
+       /* for 6601 - dma_boundary; for 6621 - dma_page_cnt
+        * exact meaning of this register is not clear.
+        */
+       alcor_write8(priv, cfg->dma, AU6601_DMA_BOUNDARY);
+
+       /* make sure all pins are set to input and VDD is off */
+       alcor_write8(priv, 0, AU6601_OUTPUT_ENABLE);
+       alcor_write8(priv, 0, AU6601_POWER_CONTROL);
+
+       alcor_write8(priv, AU6601_DETECT_EN, AU6601_DETECT_STATUS);
+       /* now we should be safe to enable IRQs */
+       alcor_unmask_sd_irqs(host);
+}
+
+static void alcor_hw_uninit(struct alcor_sdmmc_host *host)
+{
+       struct alcor_pci_priv *priv = host->alcor_pci;
+
+       alcor_mask_sd_irqs(host);
+       alcor_reset(host, AU6601_RESET_CMD | AU6601_RESET_DATA);
+
+       alcor_write8(priv, 0, AU6601_DETECT_STATUS);
+
+       alcor_write8(priv, 0, AU6601_OUTPUT_ENABLE);
+       alcor_write8(priv, 0, AU6601_POWER_CONTROL);
+
+       alcor_write8(priv, 0, AU6601_OPT);
+}
+
+static void alcor_init_mmc(struct alcor_sdmmc_host *host)
+{
+       struct mmc_host *mmc = host->mmc;
+
+       mmc->f_min = AU6601_MIN_CLOCK;
+       mmc->f_max = AU6601_MAX_CLOCK;
+       mmc->ocr_avail = MMC_VDD_33_34;
+       mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_SD_HIGHSPEED
+               | MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 | MMC_CAP_UHS_SDR50
+               | MMC_CAP_UHS_SDR104 | MMC_CAP_UHS_DDR50;
+       mmc->caps2 = MMC_CAP2_NO_SDIO;
+       mmc->ops = &alcor_sdc_ops;
+
+       /* Hardware cannot do scatter lists */
+       mmc->max_segs = AU6601_MAX_DMA_SEGMENTS;
+       mmc->max_seg_size = AU6601_MAX_DMA_BLOCK_SIZE;
+
+       mmc->max_blk_size = mmc->max_seg_size;
+       mmc->max_blk_count = mmc->max_segs;
+
+       mmc->max_req_size = mmc->max_seg_size * mmc->max_segs;
+}
+
+static int alcor_pci_sdmmc_drv_probe(struct platform_device *pdev)
+{
+       struct alcor_pci_priv *priv = pdev->dev.platform_data;
+       struct mmc_host *mmc;
+       struct alcor_sdmmc_host *host;
+       int ret;
+
+       mmc = mmc_alloc_host(sizeof(*host), &pdev->dev);
+       if (!mmc) {
+               dev_err(&pdev->dev, "Can't allocate MMC\n");
+               return -ENOMEM;
+       }
+
+       host = mmc_priv(mmc);
+       host->mmc = mmc;
+       host->dev = &pdev->dev;
+       host->cur_power_mode = MMC_POWER_UNDEFINED;
+       host->alcor_pci = priv;
+
+       /* make sure irqs are disabled */
+       alcor_write32(priv, 0, AU6601_REG_INT_ENABLE);
+       alcor_write32(priv, 0, AU6601_MS_INT_ENABLE);
+
+       ret = devm_request_threaded_irq(&pdev->dev, priv->irq,
+                       alcor_irq, alcor_irq_thread, IRQF_SHARED,
+                       DRV_NAME_ALCOR_PCI_SDMMC, host);
+
+       if (ret) {
+               dev_err(&pdev->dev, "Failed to get irq for data line\n");
+               return ret;
+       }
+
+       mutex_init(&host->cmd_mutex);
+       INIT_DELAYED_WORK(&host->timeout_work, alcor_timeout_timer);
+
+       alcor_init_mmc(host);
+       alcor_hw_init(host);
+
+       dev_set_drvdata(&pdev->dev, host);
+       mmc_add_host(mmc);
+       return 0;
+}
+
+static int alcor_pci_sdmmc_drv_remove(struct platform_device *pdev)
+{
+       struct alcor_sdmmc_host *host = dev_get_drvdata(&pdev->dev);
+
+       if (cancel_delayed_work_sync(&host->timeout_work))
+               alcor_request_complete(host, 0);
+
+       alcor_hw_uninit(host);
+       mmc_remove_host(host->mmc);
+       mmc_free_host(host->mmc);
+
+       return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int alcor_pci_sdmmc_suspend(struct device *dev)
+{
+       struct alcor_sdmmc_host *host = dev_get_drvdata(dev);
+
+       if (cancel_delayed_work_sync(&host->timeout_work))
+               alcor_request_complete(host, 0);
+
+       alcor_hw_uninit(host);
+
+       return 0;
+}
+
+static int alcor_pci_sdmmc_resume(struct device *dev)
+{
+       struct alcor_sdmmc_host *host = dev_get_drvdata(dev);
+
+       alcor_hw_init(host);
+
+       return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static SIMPLE_DEV_PM_OPS(alcor_mmc_pm_ops, alcor_pci_sdmmc_suspend,
+                        alcor_pci_sdmmc_resume);
+
+static const struct platform_device_id alcor_pci_sdmmc_ids[] = {
+       {
+               .name = DRV_NAME_ALCOR_PCI_SDMMC,
+       }, {
+               /* sentinel */
+       }
+};
+MODULE_DEVICE_TABLE(platform, alcor_pci_sdmmc_ids);
+
+static struct platform_driver alcor_pci_sdmmc_driver = {
+       .probe          = alcor_pci_sdmmc_drv_probe,
+       .remove         = alcor_pci_sdmmc_drv_remove,
+       .id_table       = alcor_pci_sdmmc_ids,
+       .driver         = {
+               .name   = DRV_NAME_ALCOR_PCI_SDMMC,
+               .pm     = &alcor_mmc_pm_ops
+       },
+};
+module_platform_driver(alcor_pci_sdmmc_driver);
+
+MODULE_AUTHOR("Oleksij Rempel <linux@rempel-privat.de>");
+MODULE_DESCRIPTION("PCI driver for Alcor Micro AU6601 Secure Digital Host Controller Interface");
+MODULE_LICENSE("GPL");