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>

1 files changed, 75 insertions, 10 deletions

diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index ba8b219d44c1..8072128e933b 100644
--- 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;
@@ -225,6 +227,19 @@ static bool mci_has_rwproof(void)
 }
 
 /*
+ * 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) {}