mmc: dw_mmc: exynos: Support eMMC's HS400 mode
authorSeungwon Jeon <tgih.jun@samsung.com>
Thu, 29 Jan 2015 02:41:57 +0000 (08:11 +0530)
committerUlf Hansson <ulf.hansson@linaro.org>
Mon, 23 Mar 2015 13:13:28 +0000 (14:13 +0100)
Implements HS400 mode support for exynos host driver.
This also include some updates as new mode is added.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
[Alim: addressed review comments]
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
drivers/mmc/host/dw_mmc-exynos.c
drivers/mmc/host/dw_mmc-exynos.h
drivers/mmc/host/dw_mmc.c
drivers/mmc/host/dw_mmc.h

index ee4fc0576c7d866b318eda917066e76e920b4f53..aad98442788bc386366b019a6166e6145b2f0017 100644 (file)
@@ -36,6 +36,8 @@ Required Properties:
   in transmit mode and CIU clock phase shift value in receive mode for double
   data rate mode operation. Refer notes below for the order of the cells and the
   valid values.
+* samsung,dw-mshc-hs400-timing: Specifies the value of CIU TX and RX clock phase
+  shift value for hs400 mode operation.
 
   Notes for the sdr-timing and ddr-timing values:
 
@@ -50,6 +52,9 @@ Required Properties:
       - if CIU clock divider value is 0 (that is divide by 1), both tx and rx
         phase shift clocks should be 0.
 
+* samsung,read-strobe-delay: RCLK (Data strobe) delay to control HS400 mode
+  (Latency value for delay line in Read path)
+
 Required properties for a slot (Deprecated - Recommend to use one slot per host):
 
 * gpios: specifies a list of gpios used for command, clock and data bus. The
@@ -82,5 +87,7 @@ Example:
                samsung,dw-mshc-ciu-div = <3>;
                samsung,dw-mshc-sdr-timing = <2 3>;
                samsung,dw-mshc-ddr-timing = <1 2>;
+               samsung,dw-mshc-hs400-timing = <0 2>;
+               samsung,read-strobe-delay = <90>;
                bus-width = <8>;
        };
index fe32948c6114dbf9dd72820f958d3337872d4ec0..0a56d766978f95b325f12466fe043056057de9da 100644 (file)
@@ -40,7 +40,12 @@ struct dw_mci_exynos_priv_data {
        u8                              ciu_div;
        u32                             sdr_timing;
        u32                             ddr_timing;
+       u32                             hs400_timing;
+       u32                             tuned_sample;
        u32                             cur_speed;
+       u32                             dqs_delay;
+       u32                             saved_dqs_en;
+       u32                             saved_strobe_ctrl;
 };
 
 static struct dw_mci_exynos_compatible {
@@ -71,6 +76,21 @@ static struct dw_mci_exynos_compatible {
        },
 };
 
+static inline u8 dw_mci_exynos_get_ciu_div(struct dw_mci *host)
+{
+       struct dw_mci_exynos_priv_data *priv = host->priv;
+
+       if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
+               return EXYNOS4412_FIXED_CIU_CLK_DIV;
+       else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4210)
+               return EXYNOS4210_FIXED_CIU_CLK_DIV;
+       else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
+                       priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
+               return SDMMC_CLKSEL_GET_DIV(mci_readl(host, CLKSEL64)) + 1;
+       else
+               return SDMMC_CLKSEL_GET_DIV(mci_readl(host, CLKSEL)) + 1;
+}
+
 static int dw_mci_exynos_priv_init(struct dw_mci *host)
 {
        struct dw_mci_exynos_priv_data *priv = host->priv;
@@ -85,6 +105,16 @@ static int dw_mci_exynos_priv_init(struct dw_mci *host)
                           SDMMC_MPSCTRL_NON_SECURE_WRITE_BIT);
        }
 
+       if (priv->ctrl_type >= DW_MCI_TYPE_EXYNOS5420) {
+               priv->saved_strobe_ctrl = mci_readl(host, HS400_DLINE_CTRL);
+               priv->saved_dqs_en = mci_readl(host, HS400_DQS_EN);
+               priv->saved_dqs_en |= AXI_NON_BLOCKING_WR;
+               mci_writel(host, HS400_DQS_EN, priv->saved_dqs_en);
+               if (!priv->dqs_delay)
+                       priv->dqs_delay =
+                               DQS_CTRL_GET_RD_DELAY(priv->saved_strobe_ctrl);
+       }
+
        return 0;
 }
 
@@ -97,6 +127,26 @@ static int dw_mci_exynos_setup_clock(struct dw_mci *host)
        return 0;
 }
 
+static void dw_mci_exynos_set_clksel_timing(struct dw_mci *host, u32 timing)
+{
+       struct dw_mci_exynos_priv_data *priv = host->priv;
+       u32 clksel;
+
+       if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
+               priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
+               clksel = mci_readl(host, CLKSEL64);
+       else
+               clksel = mci_readl(host, CLKSEL);
+
+       clksel = (clksel & ~SDMMC_CLKSEL_TIMING_MASK) | timing;
+
+       if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
+               priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
+               mci_writel(host, CLKSEL64, clksel);
+       else
+               mci_writel(host, CLKSEL, clksel);
+}
+
 #ifdef CONFIG_PM_SLEEP
 static int dw_mci_exynos_suspend(struct device *dev)
 {
@@ -172,30 +222,38 @@ static void dw_mci_exynos_prepare_command(struct dw_mci *host, u32 *cmdr)
        }
 }
 
-static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
+static void dw_mci_exynos_config_hs400(struct dw_mci *host, u32 timing)
 {
        struct dw_mci_exynos_priv_data *priv = host->priv;
-       unsigned int wanted = ios->clock;
-       unsigned long actual;
-       u8 div = priv->ciu_div + 1;
+       u32 dqs, strobe;
 
-       if (ios->timing == MMC_TIMING_MMC_DDR52) {
-               if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
-                       priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
-                       mci_writel(host, CLKSEL64, priv->ddr_timing);
-               else
-                       mci_writel(host, CLKSEL, priv->ddr_timing);
-               /* Should be double rate for DDR mode */
-               if (ios->bus_width == MMC_BUS_WIDTH_8)
-                       wanted <<= 1;
+       /*
+        * Not supported to configure register
+        * related to HS400
+        */
+       if (priv->ctrl_type < DW_MCI_TYPE_EXYNOS5420)
+               return;
+
+       dqs = priv->saved_dqs_en;
+       strobe = priv->saved_strobe_ctrl;
+
+       if (timing == MMC_TIMING_MMC_HS400) {
+               dqs |= DATA_STROBE_EN;
+               strobe = DQS_CTRL_RD_DELAY(strobe, priv->dqs_delay);
        } else {
-               if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
-                       priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
-                       mci_writel(host, CLKSEL64, priv->sdr_timing);
-               else
-                       mci_writel(host, CLKSEL, priv->sdr_timing);
+               dqs &= ~DATA_STROBE_EN;
        }
 
+       mci_writel(host, HS400_DQS_EN, dqs);
+       mci_writel(host, HS400_DLINE_CTRL, strobe);
+}
+
+static void dw_mci_exynos_adjust_clock(struct dw_mci *host, unsigned int wanted)
+{
+       struct dw_mci_exynos_priv_data *priv = host->priv;
+       unsigned long actual;
+       u8 div;
+       int ret;
        /*
         * Don't care if wanted clock is zero or
         * ciu clock is unavailable
@@ -207,17 +265,52 @@ static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
        if (wanted < EXYNOS_CCLKIN_MIN)
                wanted = EXYNOS_CCLKIN_MIN;
 
-       if (wanted != priv->cur_speed) {
-               int ret = clk_set_rate(host->ciu_clk, wanted * div);
-               if (ret)
-                       dev_warn(host->dev,
-                               "failed to set clk-rate %u error: %d\n",
-                                wanted * div, ret);
-               actual = clk_get_rate(host->ciu_clk);
-               host->bus_hz = actual / div;
-               priv->cur_speed = wanted;
-               host->current_speed = 0;
+       if (wanted == priv->cur_speed)
+               return;
+
+       div = dw_mci_exynos_get_ciu_div(host);
+       ret = clk_set_rate(host->ciu_clk, wanted * div);
+       if (ret)
+               dev_warn(host->dev,
+                       "failed to set clk-rate %u error: %d\n",
+                       wanted * div, ret);
+       actual = clk_get_rate(host->ciu_clk);
+       host->bus_hz = actual / div;
+       priv->cur_speed = wanted;
+       host->current_speed = 0;
+}
+
+static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
+{
+       struct dw_mci_exynos_priv_data *priv = host->priv;
+       unsigned int wanted = ios->clock;
+       u32 timing = ios->timing, clksel;
+
+       switch (timing) {
+       case MMC_TIMING_MMC_HS400:
+               /* Update tuned sample timing */
+               clksel = SDMMC_CLKSEL_UP_SAMPLE(
+                               priv->hs400_timing, priv->tuned_sample);
+               wanted <<= 1;
+               break;
+       case MMC_TIMING_MMC_DDR52:
+               clksel = priv->ddr_timing;
+               /* Should be double rate for DDR mode */
+               if (ios->bus_width == MMC_BUS_WIDTH_8)
+                       wanted <<= 1;
+               break;
+       default:
+               clksel = priv->sdr_timing;
        }
+
+       /* Set clock timing for the requested speed mode*/
+       dw_mci_exynos_set_clksel_timing(host, clksel);
+
+       /* Configure setting for HS400 */
+       dw_mci_exynos_config_hs400(host, timing);
+
+       /* Configure clock rate */
+       dw_mci_exynos_adjust_clock(host, wanted);
 }
 
 static int dw_mci_exynos_parse_dt(struct dw_mci *host)
@@ -260,6 +353,16 @@ static int dw_mci_exynos_parse_dt(struct dw_mci *host)
                return ret;
 
        priv->ddr_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1], div);
+
+       ret = of_property_read_u32_array(np,
+                       "samsung,dw-mshc-hs400-timing", timing, 2);
+       if (!ret && of_property_read_u32(np,
+                               "samsung,read-strobe-delay", &priv->dqs_delay))
+               dev_dbg(host->dev,
+                       "read-strobe-delay is not found, assuming usage of default value\n");
+
+       priv->hs400_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1],
+                                               HS400_FIXED_CIU_CLK_DIV);
        host->priv = priv;
        return 0;
 }
@@ -285,7 +388,7 @@ static inline void dw_mci_exynos_set_clksmpl(struct dw_mci *host, u8 sample)
                clksel = mci_readl(host, CLKSEL64);
        else
                clksel = mci_readl(host, CLKSEL);
-       clksel = (clksel & ~0x7) | SDMMC_CLKSEL_CCLK_SAMPLE(sample);
+       clksel = SDMMC_CLKSEL_UP_SAMPLE(clksel, sample);
        if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
                priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
                mci_writel(host, CLKSEL64, clksel);
@@ -304,13 +407,16 @@ static inline u8 dw_mci_exynos_move_next_clksmpl(struct dw_mci *host)
                clksel = mci_readl(host, CLKSEL64);
        else
                clksel = mci_readl(host, CLKSEL);
+
        sample = (clksel + 1) & 0x7;
-       clksel = (clksel & ~0x7) | sample;
+       clksel = SDMMC_CLKSEL_UP_SAMPLE(clksel, sample);
+
        if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
                priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
                mci_writel(host, CLKSEL64, clksel);
        else
                mci_writel(host, CLKSEL, clksel);
+
        return sample;
 }
 
@@ -343,6 +449,7 @@ out:
 static int dw_mci_exynos_execute_tuning(struct dw_mci_slot *slot)
 {
        struct dw_mci *host = slot->host;
+       struct dw_mci_exynos_priv_data *priv = host->priv;
        struct mmc_host *mmc = slot->mmc;
        u8 start_smpl, smpl, candiates = 0;
        s8 found = -1;
@@ -360,14 +467,27 @@ static int dw_mci_exynos_execute_tuning(struct dw_mci_slot *slot)
        } while (start_smpl != smpl);
 
        found = dw_mci_exynos_get_best_clksmpl(candiates);
-       if (found >= 0)
+       if (found >= 0) {
                dw_mci_exynos_set_clksmpl(host, found);
-       else
+               priv->tuned_sample = found;
+       } else {
                ret = -EIO;
+       }
 
        return ret;
 }
 
+int dw_mci_exynos_prepare_hs400_tuning(struct dw_mci *host,
+                                       struct mmc_ios *ios)
+{
+       struct dw_mci_exynos_priv_data *priv = host->priv;
+
+       dw_mci_exynos_set_clksel_timing(host, priv->hs400_timing);
+       dw_mci_exynos_adjust_clock(host, (ios->clock) << 1);
+
+       return 0;
+}
+
 /* Common capabilities of Exynos4/Exynos5 SoC */
 static unsigned long exynos_dwmmc_caps[4] = {
        MMC_CAP_1_8V_DDR | MMC_CAP_8_BIT_DATA | MMC_CAP_CMD23,
@@ -384,6 +504,7 @@ static const struct dw_mci_drv_data exynos_drv_data = {
        .set_ios                = dw_mci_exynos_set_ios,
        .parse_dt               = dw_mci_exynos_parse_dt,
        .execute_tuning         = dw_mci_exynos_execute_tuning,
+       .prepare_hs400_tuning   = dw_mci_exynos_prepare_hs400_tuning,
 };
 
 static const struct of_device_id dw_mci_exynos_match[] = {
index 7872ce586b558e07461c748f600f6ef6777bb12b..595c934e6166cf1b9aef2c18a8a28ec3c3062163 100644 (file)
 #ifndef _DW_MMC_EXYNOS_H_
 #define _DW_MMC_EXYNOS_H_
 
-/* Extended Register's Offset */
 #define SDMMC_CLKSEL                   0x09C
 #define SDMMC_CLKSEL64                 0x0A8
 
+/* Extended Register's Offset */
+#define SDMMC_HS400_DQS_EN             0x180
+#define SDMMC_HS400_ASYNC_FIFO_CTRL    0x184
+#define SDMMC_HS400_DLINE_CTRL         0x188
+
 /* CLKSEL register defines */
 #define SDMMC_CLKSEL_CCLK_SAMPLE(x)    (((x) & 7) << 0)
 #define SDMMC_CLKSEL_CCLK_DRIVE(x)     (((x) & 7) << 16)
 #define SDMMC_CLKSEL_CCLK_DIVIDER(x)   (((x) & 7) << 24)
 #define SDMMC_CLKSEL_GET_DRV_WD3(x)    (((x) >> 16) & 0x7)
+#define SDMMC_CLKSEL_GET_DIV(x)                (((x) >> 24) & 0x7)
+#define SDMMC_CLKSEL_UP_SAMPLE(x, y)   (((x) & ~SDMMC_CLKSEL_CCLK_SAMPLE(7)) |\
+                                        SDMMC_CLKSEL_CCLK_SAMPLE(y))
 #define SDMMC_CLKSEL_TIMING(x, y, z)   (SDMMC_CLKSEL_CCLK_SAMPLE(x) |  \
                                         SDMMC_CLKSEL_CCLK_DRIVE(y) |   \
                                         SDMMC_CLKSEL_CCLK_DIVIDER(z))
+#define SDMMC_CLKSEL_TIMING_MASK       SDMMC_CLKSEL_TIMING(0x7, 0x7, 0x7)
 #define SDMMC_CLKSEL_WAKEUP_INT                BIT(11)
 
+/* RCLK_EN register defines */
+#define DATA_STROBE_EN                 BIT(0)
+#define AXI_NON_BLOCKING_WR    BIT(7)
+
+/* DLINE_CTRL register defines */
+#define DQS_CTRL_RD_DELAY(x, y)                (((x) & ~0x3FF) | ((y) & 0x3FF))
+#define DQS_CTRL_GET_RD_DELAY(x)       ((x) & 0x3FF)
+
 /* Protector Register */
 #define SDMMC_EMMCP_BASE       0x1000
 #define SDMMC_MPSECURITY       (SDMMC_EMMCP_BASE + 0x0010)
@@ -49,6 +65,7 @@
 /* Fixed clock divider */
 #define EXYNOS4210_FIXED_CIU_CLK_DIV   2
 #define EXYNOS4412_FIXED_CIU_CLK_DIV   4
+#define HS400_FIXED_CIU_CLK_DIV                1
 
 /* Minimal required clock frequency for cclkin, unit: HZ */
 #define EXYNOS_CCLKIN_MIN      50000000
index 4d2e3c2e183057ddd13e29c1d1b8398a01dd7c5c..f30ef6921d08e193595451f92b5323bd401774f0 100644 (file)
@@ -1084,7 +1084,8 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
        regs = mci_readl(slot->host, UHS_REG);
 
        /* DDR mode set */
-       if (ios->timing == MMC_TIMING_MMC_DDR52)
+       if (ios->timing == MMC_TIMING_MMC_DDR52 ||
+           ios->timing == MMC_TIMING_MMC_HS400)
                regs |= ((0x1 << slot->id) << 16);
        else
                regs &= ~((0x1 << slot->id) << 16);
@@ -1323,6 +1324,18 @@ static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode)
        return err;
 }
 
+int dw_mci_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+       struct dw_mci_slot *slot = mmc_priv(mmc);
+       struct dw_mci *host = slot->host;
+       const struct dw_mci_drv_data *drv_data = host->drv_data;
+
+       if (drv_data && drv_data->prepare_hs400_tuning)
+               return drv_data->prepare_hs400_tuning(host, ios);
+
+       return 0;
+}
+
 static const struct mmc_host_ops dw_mci_ops = {
        .request                = dw_mci_request,
        .pre_req                = dw_mci_pre_req,
@@ -1335,6 +1348,7 @@ static const struct mmc_host_ops dw_mci_ops = {
        .card_busy              = dw_mci_card_busy,
        .start_signal_voltage_switch = dw_mci_switch_voltage,
        .init_card              = dw_mci_init_card,
+       .prepare_hs400_tuning   = dw_mci_prepare_hs400_tuning,
 };
 
 static void dw_mci_request_end(struct dw_mci *host, struct mmc_request *mrq)
index 18c4afe683b83c60d0941230b34735a64f58a6e4..d2398675fd356a279e156eabc2eac6f5a8705e9e 100644 (file)
@@ -271,5 +271,7 @@ struct dw_mci_drv_data {
        void            (*set_ios)(struct dw_mci *host, struct mmc_ios *ios);
        int             (*parse_dt)(struct dw_mci *host);
        int             (*execute_tuning)(struct dw_mci_slot *slot);
+       int             (*prepare_hs400_tuning)(struct dw_mci *host,
+                                               struct mmc_ios *ios);
 };
 #endif /* _DW_MMC_H_ */