mmc: atmel-mci: new MCI2 module support in atmel-mci driver

This new revision of the IP adds some improvements to the MCI already
present in several Atmel SOC.

Some new registers are added and a particular way of handling DMA
interaction lead to a new sequence in function call which is backward
compatible: On MCI2, we must set the DMAEN bit to enable the DMA
handshaking interface.  This must happen before the data transfer command
is sent.

A new function is able to differentiate MCI2 code and is based on
knowledge of processor id (cpu_is_xxx()).

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index ba8b219..8072128 100644 (file)
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -94,6 +94,7 @@ struct atmel_mci_dma {
  * @need_clock_update: Update the clock rate before the next request.
  * @need_reset: Reset controller before next request.
  * @mode_reg: Value of the MR register.
+ * @cfg_reg: Value of the CFG register.
  * @bus_hz: The rate of @mck in Hz. This forms the basis for MMC bus
  *     rate and timeout calculations.
  * @mapbase: Physical address of the MMIO registers.
@@ -157,6 +158,7 @@ struct atmel_mci {
        bool                    need_clock_update;
        bool                    need_reset;
        u32                     mode_reg;
+       u32                     cfg_reg;
        unsigned long           bus_hz;
        unsigned long           mapbase;
        struct clk              *mck;
@@ -224,6 +226,19 @@ static bool mci_has_rwproof(void)
                return true;
 }
 
+/*
+ * The new MCI2 module isn't 100% compatible with the old MCI module,
+ * and it has a few nice features which we want to use...
+ */
+static inline bool atmci_is_mci2(void)
+{
+       if (cpu_is_at91sam9g45())
+               return true;
+
+       return false;
+}
+
+
 /*
  * The debugfs stuff below is mostly optimized away when
  * CONFIG_DEBUG_FS is not set.
@@ -359,12 +374,33 @@ static int atmci_regs_show(struct seq_file *s, void *v)
                        buf[MCI_BLKR / 4],
                        buf[MCI_BLKR / 4] & 0xffff,
                        (buf[MCI_BLKR / 4] >> 16) & 0xffff);
+       if (atmci_is_mci2())
+               seq_printf(s, "CSTOR:\t0x%08x\n", buf[MCI_CSTOR / 4]);
 
        /* Don't read RSPR and RDR; it will consume the data there */
 
        atmci_show_status_reg(s, "SR", buf[MCI_SR / 4]);
        atmci_show_status_reg(s, "IMR", buf[MCI_IMR / 4]);
 
+       if (atmci_is_mci2()) {
+               u32 val;
+
+               val = buf[MCI_DMA / 4];
+               seq_printf(s, "DMA:\t0x%08x OFFSET=%u CHKSIZE=%u%s\n",
+                               val, val & 3,
+                               ((val >> 4) & 3) ?
+                                       1 << (((val >> 4) & 3) + 1) : 1,
+                               val & MCI_DMAEN ? " DMAEN" : "");
+
+               val = buf[MCI_CFG / 4];
+               seq_printf(s, "CFG:\t0x%08x%s%s%s%s\n",
+                               val,
+                               val & MCI_CFG_FIFOMODE_1DATA ? " FIFOMODE_ONE_DATA" : "",
+                               val & MCI_CFG_FERRCTRL_COR ? " FERRCTRL_CLEAR_ON_READ" : "",
+                               val & MCI_CFG_HSMODE ? " HSMODE" : "",
+                               val & MCI_CFG_LSYNC ? " LSYNC" : "");
+       }
+
        kfree(buf);
 
        return 0;
@@ -559,6 +595,10 @@ static void atmci_dma_complete(void *arg)
 
        dev_vdbg(&host->pdev->dev, "DMA complete\n");
 
+       if (atmci_is_mci2())
+               /* Disable DMA hardware handshaking on MCI */
+               mci_writel(host, DMA, mci_readl(host, DMA) & ~MCI_DMAEN);
+
        atmci_dma_cleanup(host);
 
        /*
@@ -594,7 +634,7 @@ static void atmci_dma_complete(void *arg)
 }
 
 static int
-atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data)
+atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data)
 {
        struct dma_chan                 *chan;
        struct dma_async_tx_descriptor  *desc;
@@ -626,6 +666,9 @@ atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data)
        if (!chan)
                return -ENODEV;
 
+       if (atmci_is_mci2())
+               mci_writel(host, DMA, MCI_DMA_CHKSIZE(3) | MCI_DMAEN);
+
        if (data->flags & MMC_DATA_READ)
                direction = DMA_FROM_DEVICE;
        else
@@ -643,10 +686,6 @@ atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data)
        host->dma.data_desc = desc;
        desc->callback = atmci_dma_complete;
        desc->callback_param = host;
-       desc->tx_submit(desc);
-
-       /* Go! */
-       chan->device->device_issue_pending(chan);
 
        return 0;
 unmap_exit:
@@ -654,13 +693,26 @@ unmap_exit:
        return -ENOMEM;
 }
 
+static void atmci_submit_data(struct atmel_mci *host)
+{
+       struct dma_chan                 *chan = host->data_chan;
+       struct dma_async_tx_descriptor  *desc = host->dma.data_desc;
+
+       if (chan) {
+               desc->tx_submit(desc);
+               chan->device->device_issue_pending(chan);
+       }
+}
+
 #else /* CONFIG_MMC_ATMELMCI_DMA */
 
-static int atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data)
+static int atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data)
 {
        return -ENOSYS;
 }
 
+static void atmci_submit_data(struct atmel_mci *host) {}
+
 static void atmci_stop_dma(struct atmel_mci *host)
 {
        /* Data transfer was stopped by the interrupt handler */
@@ -674,7 +726,7 @@ static void atmci_stop_dma(struct atmel_mci *host)
  * Returns a mask of interrupt flags to be enabled after the whole
  * request has been prepared.
  */
-static u32 atmci_submit_data(struct atmel_mci *host, struct mmc_data *data)
+static u32 atmci_prepare_data(struct atmel_mci *host, struct mmc_data *data)
 {
        u32 iflags;
 
@@ -685,7 +737,7 @@ static u32 atmci_submit_data(struct atmel_mci *host, struct mmc_data *data)
        host->data = data;
 
        iflags = ATMCI_DATA_ERROR_FLAGS;
-       if (atmci_submit_data_dma(host, data)) {
+       if (atmci_prepare_data_dma(host, data)) {
                host->data_chan = NULL;
 
                /*
@@ -731,6 +783,8 @@ static void atmci_start_request(struct atmel_mci *host,
                mci_writel(host, CR, MCI_CR_SWRST);
                mci_writel(host, CR, MCI_CR_MCIEN);
                mci_writel(host, MR, host->mode_reg);
+               if (atmci_is_mci2())
+                       mci_writel(host, CFG, host->cfg_reg);
                host->need_reset = false;
        }
        mci_writel(host, SDCR, slot->sdc_reg);
@@ -746,6 +800,7 @@ static void atmci_start_request(struct atmel_mci *host,
                while (!(mci_readl(host, SR) & MCI_CMDRDY))
                        cpu_relax();
        }
+       iflags = 0;
        data = mrq->data;
        if (data) {
                atmci_set_timeout(host, slot, data);
@@ -755,15 +810,17 @@ static void atmci_start_request(struct atmel_mci *host,
                                | MCI_BLKLEN(data->blksz));
                dev_vdbg(&slot->mmc->class_dev, "BLKR=0x%08x\n",
                        MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz));
+
+               iflags |= atmci_prepare_data(host, data);
        }
 
-       iflags = MCI_CMDRDY;
+       iflags |= MCI_CMDRDY;
        cmd = mrq->cmd;
        cmdflags = atmci_prepare_command(slot->mmc, cmd);
        atmci_start_command(host, cmd, cmdflags);
 
        if (data)
-               iflags |= atmci_submit_data(host, data);
+               atmci_submit_data(host);
 
        if (mrq->stop) {
                host->stop_cmdr = atmci_prepare_command(slot->mmc, mrq->stop);
@@ -859,6 +916,8 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
                        clk_enable(host->mck);
                        mci_writel(host, CR, MCI_CR_SWRST);
                        mci_writel(host, CR, MCI_CR_MCIEN);
+                       if (atmci_is_mci2())
+                               mci_writel(host, CFG, host->cfg_reg);
                }
 
                /*
@@ -1097,6 +1156,8 @@ static void atmci_detect_change(unsigned long data)
                                mci_writel(host, CR, MCI_CR_SWRST);
                                mci_writel(host, CR, MCI_CR_MCIEN);
                                mci_writel(host, MR, host->mode_reg);
+                               if (atmci_is_mci2())
+                                       mci_writel(host, CFG, host->cfg_reg);
 
                                host->data = NULL;
                                host->cmd = NULL;
@@ -1620,6 +1681,10 @@ static void atmci_configure_dma(struct atmel_mci *host)
        }
        if (!host->dma.chan)
                dev_notice(&host->pdev->dev, "DMA not available, using PIO\n");
+       else
+               dev_info(&host->pdev->dev,
+                                       "Using %s for DMA transfers\n",
+                                       dma_chan_name(host->dma.chan));
 }
 #else
 static void atmci_configure_dma(struct atmel_mci *host) {}