[PATCH 4/8] sdhci: sdhci-esdhci-imx: add sd3.0 clock tuning support
Dong Aisheng
b29396 at freescale.com
Wed Sep 4 08:54:13 EDT 2013
Freescale i.MX6Q/DL uSDHC clock tuning progress is a little different from
the standard tuning process defined in host controller spec v3.0.
Thus we use platform_execute_tuning instead of standard sdhci tuning.
The main difference are:
1) not only generate Buffer Read Ready interrupt when tuning is performing.
It generates all other DATA interrupts like the normal data command.
2) SDHCI_CTRL_EXEC_TUNING is not automatically cleared by HW,
instead it's controlled by SW.
3) SDHCI_CTRL_TUNED_CLK is not automatically set by HW,
it's controlled by SW.
4) the clock delay for every tuning is set by SW.
Signed-off-by: Dong Aisheng <b29396 at freescale.com>
---
drivers/mmc/host/sdhci-esdhc-imx.c | 194 +++++++++++++++++++++++++++++++++++-
1 files changed, 193 insertions(+), 1 deletions(-)
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 3118a82..36b9f63 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -34,9 +34,21 @@
#define ESDHC_WTMK_LVL 0x44
#define ESDHC_MIX_CTRL 0x48
#define ESDHC_MIX_CTRL_AC23EN (1 << 7)
+#define ESDHC_MIX_CTRL_EXE_TUNE (1 << 22)
+#define ESDHC_MIX_CTRL_SMPCLK_SEL (1 << 23)
+#define ESDHC_MIX_CTRL_AUTO_TUNE (1 << 24)
+#define ESDHC_MIX_CTRL_FBCLK_SEL (1 << 25)
/* Bits 3 and 6 are not SDHCI standard definitions */
#define ESDHC_MIX_CTRL_SDHCI_MASK 0xb7
+/* tune control register */
+#define ESDHC_TUNE_CTRL_STATUS 0x68
+#define ESDHC_TUNE_CTRL_STEP 1
+#define ESDHC_TUNE_CTRL_MIN 0
+#define ESDHC_TUNE_CTRL_MAX ((1 << 7) - 1)
+
+#define ESDHC_TUNING_BLOCK_PATTERN_LEN 64
+
/*
* Our interpretation of the SDHCI_HOST_CONTROL register
*/
@@ -87,7 +99,7 @@ struct pltfm_imx_data {
MULTIBLK_IN_PROCESS, /* exact multiblock cmd in process */
WAIT_FOR_INT, /* sent CMD12, waiting for response INT */
} multiblock_status;
-
+ u32 uhs_mode;
};
static struct platform_device_id imx_esdhc_devtype[] = {
@@ -161,6 +173,17 @@ static u32 esdhc_readl_le(struct sdhci_host *host, int reg)
struct pltfm_imx_data *imx_data = pltfm_host->priv;
u32 val = readl(host->ioaddr + reg);
+ if (unlikely(reg == SDHCI_PRESENT_STATE)) {
+ u32 fsl_prss = val;
+ val = 0;
+ /* save the least 20 bits */
+ val |= fsl_prss & 0x000FFFFF;
+ /* move dat[0-3] bits */
+ val |= (fsl_prss & 0x0F000000) >> 4;
+ /* move cmd line bit */
+ val |= (fsl_prss & 0x00800000) << 1;
+ }
+
if (unlikely(reg == SDHCI_CAPABILITIES)) {
/* In FSL esdhc IC module, only bit20 is used to indicate the
* ADMA2 capability of esdhc, but this bit is messed up on
@@ -175,6 +198,17 @@ static u32 esdhc_readl_le(struct sdhci_host *host, int reg)
}
}
+ if (unlikely(reg == SDHCI_CAPABILITIES_1) && is_imx6q_usdhc(imx_data))
+ val = SDHCI_SUPPORT_DDR50 | SDHCI_SUPPORT_SDR104
+ | SDHCI_SUPPORT_SDR50;
+
+ if (unlikely(reg == SDHCI_MAX_CURRENT) && is_imx6q_usdhc(imx_data)) {
+ val = 0;
+ val |= 0xFF << SDHCI_MAX_CURRENT_330_SHIFT;
+ val |= 0xFF << SDHCI_MAX_CURRENT_300_SHIFT;
+ val |= 0xFF << SDHCI_MAX_CURRENT_180_SHIFT;
+ }
+
if (unlikely(reg == SDHCI_INT_STATUS)) {
if (val & ESDHC_INT_VENDOR_SPEC_DMA_ERR) {
val &= ~ESDHC_INT_VENDOR_SPEC_DMA_ERR;
@@ -253,6 +287,8 @@ static u16 esdhc_readw_le(struct sdhci_host *host, int reg)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct pltfm_imx_data *imx_data = pltfm_host->priv;
+ u16 ret = 0;
+ u32 val;
if (unlikely(reg == SDHCI_HOST_VERSION)) {
reg ^= 2;
@@ -265,6 +301,25 @@ static u16 esdhc_readw_le(struct sdhci_host *host, int reg)
}
}
+ if (unlikely(reg == SDHCI_HOST_CONTROL2)) {
+ val = readl(host->ioaddr + ESDHC_VENDOR_SPEC);
+ if (val & ESDHC_VENDOR_SPEC_VSELECT)
+ ret |= SDHCI_CTRL_VDD_180;
+
+ if (is_imx6q_usdhc(imx_data)) {
+ val = readl(host->ioaddr + ESDHC_MIX_CTRL);
+ if (val & ESDHC_MIX_CTRL_EXE_TUNE)
+ ret |= SDHCI_CTRL_EXEC_TUNING;
+ if (val & ESDHC_MIX_CTRL_SMPCLK_SEL)
+ ret |= SDHCI_CTRL_TUNED_CLK;
+ }
+
+ ret |= (imx_data->uhs_mode & SDHCI_CTRL_UHS_MASK);
+ ret &= ~SDHCI_CTRL_PRESET_VAL_ENABLE;
+
+ return ret;
+ }
+
return readw(host->ioaddr + reg);
}
@@ -272,8 +327,32 @@ static void esdhc_writew_le(struct sdhci_host *host, u16 val, int reg)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct pltfm_imx_data *imx_data = pltfm_host->priv;
+ u32 new_val = 0;
switch (reg) {
+ case SDHCI_CLOCK_CONTROL:
+ new_val = readl(host->ioaddr + ESDHC_VENDOR_SPEC);
+ if (val & SDHCI_CLOCK_CARD_EN)
+ new_val |= ESDHC_VENDOR_SPEC_FRC_SDCLK_ON;
+ else
+ new_val &= ~ESDHC_VENDOR_SPEC_FRC_SDCLK_ON;
+ writel(new_val, host->ioaddr + ESDHC_VENDOR_SPEC);
+ return;
+ case SDHCI_HOST_CONTROL2:
+ new_val = readl(host->ioaddr + ESDHC_VENDOR_SPEC);
+ if (val & SDHCI_CTRL_VDD_180)
+ new_val |= ESDHC_VENDOR_SPEC_VSELECT;
+ else
+ new_val &= ~ESDHC_VENDOR_SPEC_VSELECT;
+ writel(new_val, host->ioaddr + ESDHC_VENDOR_SPEC);
+ imx_data->uhs_mode = val & SDHCI_CTRL_UHS_MASK;
+ new_val = readl(host->ioaddr + ESDHC_MIX_CTRL);
+ if (val & SDHCI_CTRL_TUNED_CLK)
+ new_val |= ESDHC_MIX_CTRL_SMPCLK_SEL;
+ else
+ new_val &= ~ESDHC_MIX_CTRL_SMPCLK_SEL;
+ writel(new_val , host->ioaddr + ESDHC_MIX_CTRL);
+ return;
case SDHCI_TRANSFER_MODE:
if ((imx_data->flags & ESDHC_FLAG_MULTIBLK_NO_INT)
&& (host->cmd->opcode == SD_IO_RW_EXTENDED)
@@ -451,6 +530,118 @@ static int esdhc_pltfm_bus_width(struct sdhci_host *host, int width)
return 0;
}
+static void esdhc_prepare_tuning(struct sdhci_host *host, u32 val)
+{
+ u32 reg;
+
+ reg = readl(host->ioaddr + ESDHC_MIX_CTRL);
+ reg |= ESDHC_MIX_CTRL_EXE_TUNE | ESDHC_MIX_CTRL_SMPCLK_SEL |
+ ESDHC_MIX_CTRL_FBCLK_SEL;
+ writel(reg, host->ioaddr + ESDHC_MIX_CTRL);
+ writel((val << 8), host->ioaddr + ESDHC_TUNE_CTRL_STATUS);
+ dev_dbg(mmc_dev(host->mmc),
+ "tunning with delay 0x%x ESDHC_TUNE_CTRL_STATUS 0x%x\n",
+ val, readl(host->ioaddr + ESDHC_TUNE_CTRL_STATUS));
+}
+
+static void request_done(struct mmc_request *mrq)
+{
+ complete(&mrq->completion);
+}
+
+static int esdhc_send_tuning_cmd(struct sdhci_host *host, u32 opcode)
+{
+ struct mmc_command cmd = {0};
+ struct mmc_request mrq = {0};
+ struct mmc_data data = {0};
+ struct scatterlist sg;
+ char tuning_pattern[ESDHC_TUNING_BLOCK_PATTERN_LEN];
+
+ cmd.opcode = opcode;
+ cmd.arg = 0;
+ cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
+
+ data.blksz = ESDHC_TUNING_BLOCK_PATTERN_LEN;
+ data.blocks = 1;
+ data.flags = MMC_DATA_READ;
+ data.sg = &sg;
+ data.sg_len = 1;
+
+ sg_init_one(&sg, tuning_pattern, sizeof(tuning_pattern));
+
+ mrq.cmd = &cmd;
+ mrq.cmd->mrq = &mrq;
+ mrq.data = &data;
+ mrq.data->mrq = &mrq;
+ mrq.cmd->data = mrq.data;
+
+ mrq.done = request_done;
+ init_completion(&(mrq.completion));
+
+ disable_irq(host->irq);
+ spin_lock(&host->lock);
+ host->mrq = &mrq;
+
+ sdhci_send_command(host, mrq.cmd);
+
+ spin_unlock(&host->lock);
+ enable_irq(host->irq);
+
+ wait_for_completion(&mrq.completion);
+
+ if (cmd.error)
+ return cmd.error;
+ if (data.error)
+ return data.error;
+
+ return 0;
+}
+
+static void esdhc_post_tuning(struct sdhci_host *host)
+{
+ u32 reg;
+
+ reg = readl(host->ioaddr + ESDHC_MIX_CTRL);
+ reg &= ~ESDHC_MIX_CTRL_EXE_TUNE;
+ writel(reg, host->ioaddr + ESDHC_MIX_CTRL);
+}
+
+static int esdhc_executing_tuning(struct sdhci_host *host, u32 opcode)
+{
+ int min, max, avg, ret;
+
+ /* find the mininum delay first which can pass tuning*/
+ min = ESDHC_TUNE_CTRL_MIN;
+ while (min < ESDHC_TUNE_CTRL_MAX) {
+ esdhc_prepare_tuning(host, min);
+ if (!esdhc_send_tuning_cmd(host, opcode))
+ break;
+ min += ESDHC_TUNE_CTRL_STEP;
+ }
+
+ /* find the maxinum delay which can not pass tuning*/
+ max = min + ESDHC_TUNE_CTRL_STEP;
+ while (max < ESDHC_TUNE_CTRL_MAX) {
+ esdhc_prepare_tuning(host, max);
+ if (esdhc_send_tuning_cmd(host, opcode)) {
+ max -= ESDHC_TUNE_CTRL_STEP;
+ break;
+ }
+ max += ESDHC_TUNE_CTRL_STEP;
+ }
+
+ /* use average delay to get the best timing */
+ avg = (min + max) / 2;
+ esdhc_prepare_tuning(host, avg);
+ ret = esdhc_send_tuning_cmd(host, opcode);
+ esdhc_post_tuning(host);
+
+ dev_dbg(mmc_dev(host->mmc), "tunning %s at 0x%x ret %d\n",
+ ret ? "failed" : "passed", avg, ret);
+
+ return ret;
+}
+
static const struct sdhci_ops sdhci_esdhc_ops = {
.read_l = esdhc_readl_le,
.read_w = esdhc_readw_le,
@@ -462,6 +653,7 @@ static const struct sdhci_ops sdhci_esdhc_ops = {
.get_min_clock = esdhc_pltfm_get_min_clock,
.get_ro = esdhc_pltfm_get_ro,
.platform_bus_width = esdhc_pltfm_bus_width,
+ .platform_execute_tuning = esdhc_executing_tuning,
};
static const struct sdhci_pltfm_data sdhci_esdhc_imx_pdata = {
--
1.7.1
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