1 files changed, 37 insertions, 18 deletions

diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 9819dc09ce08..e94476beca18 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -77,6 +77,7 @@ struct atmel_mci_caps {
         bool    has_cstor_reg;
         bool    has_highspeed;
         bool    has_rwproof;
+        bool    has_odd_clk_div;
 };
 
 struct atmel_mci_dma {
@@ -482,7 +483,14 @@ err:
 static inline unsigned int atmci_ns_to_clocks(struct atmel_mci *host,
                                         unsigned int ns)
 {
-        return (ns * (host->bus_hz / 1000000) + 999) / 1000;
+        /*
+         * It is easier here to use us instead of ns for the timeout,
+         * it prevents from overflows during calculation.
+         */
+        unsigned int us = DIV_ROUND_UP(ns, 1000);
+
+        /* Maximum clock frequency is host->bus_hz/2 */
+        return us * (DIV_ROUND_UP(host->bus_hz, 2000000));
 }
 
 static void atmci_set_timeout(struct atmel_mci *host,
@@ -1127,16 +1135,27 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
                 }
 
                 /* Calculate clock divider */
-                clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * clock_min) - 1;
-                if (clkdiv > 255) {
-                        dev_warn(&mmc->class_dev,
-                                "clock %u too slow; using %lu\n",
-                                clock_min, host->bus_hz / (2 * 256));
-                        clkdiv = 255;
+                if (host->caps.has_odd_clk_div) {
+                        clkdiv = DIV_ROUND_UP(host->bus_hz, clock_min) - 2;
+                        if (clkdiv > 511) {
+                                dev_warn(&mmc->class_dev,
+                                         "clock %u too slow; using %lu\n",
+                                         clock_min, host->bus_hz / (511 + 2));
+                                clkdiv = 511;
+                        }
+                        host->mode_reg = ATMCI_MR_CLKDIV(clkdiv >> 1)
+                                         | ATMCI_MR_CLKODD(clkdiv & 1);
+                } else {
+                        clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * clock_min) - 1;
+                        if (clkdiv > 255) {
+                                dev_warn(&mmc->class_dev,
+                                         "clock %u too slow; using %lu\n",
+                                         clock_min, host->bus_hz / (2 * 256));
+                                clkdiv = 255;
+                        }
+                        host->mode_reg = ATMCI_MR_CLKDIV(clkdiv);
                 }
 
-                host->mode_reg = ATMCI_MR_CLKDIV(clkdiv);
-
                 /*
                  * WRPROOF and RDPROOF prevent overruns/underruns by
                  * stopping the clock when the FIFO is full/empty.
@@ -2007,35 +2026,35 @@ static void __init atmci_get_cap(struct atmel_mci *host)
                         "version: 0x%x\n", version);
 
         host->caps.has_dma = 0;
-        host->caps.has_pdc = 0;
+        host->caps.has_pdc = 1;
         host->caps.has_cfg_reg = 0;
         host->caps.has_cstor_reg = 0;
         host->caps.has_highspeed = 0;
         host->caps.has_rwproof = 0;
+        host->caps.has_odd_clk_div = 0;
 
         /* keep only major version number */
         switch (version & 0xf00) {
-        case 0x100:
-        case 0x200:
-                host->caps.has_pdc = 1;
-                host->caps.has_rwproof = 1;
-                break;
-        case 0x300:
-        case 0x400:
         case 0x500:
+                host->caps.has_odd_clk_div = 1;
+        case 0x400:
+        case 0x300:
 #ifdef CONFIG_AT_HDMAC
                 host->caps.has_dma = 1;
 #else
-                host->caps.has_dma = 0;
                 dev_info(&host->pdev->dev,
                         "has dma capability but dma engine is not selected, then use pio\n");
 #endif
+                host->caps.has_pdc = 0;
                 host->caps.has_cfg_reg = 1;
                 host->caps.has_cstor_reg = 1;
                 host->caps.has_highspeed = 1;
+        case 0x200:
                 host->caps.has_rwproof = 1;
+        case 0x100:
                 break;
         default:
+                host->caps.has_pdc = 0;
                 dev_warn(&host->pdev->dev,
                                 "Unmanaged mci version, set minimum capabilities\n");
                 break;