[PATCH 4/5] mmc: mtk-sd: enable internal card-detect logic.

From: NeilBrown
Date: Tue Apr 16 2019 - 00:48:34 EST


The mtk-sd silicon has integrated card-detect logic that is
enabled, at least, on the MT7621 as used in the GNUBEE NAS.

If the sdhci isn't marked non-removable and doesn't have a
cd-gpio configured, assume the internal cd logic should be used.

Signed-off-by: NeilBrown <neil@xxxxxxxxxx>
---
drivers/mmc/host/mtk-sd.c | 58 ++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 54 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index d379f2ece305..341cf5f03429 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -300,6 +300,8 @@
#define CMD_TIMEOUT (HZ/10 * 5) /* 100ms x5 */
#define DAT_TIMEOUT (HZ * 5) /* 1000ms x5 */

+#define DEFAULT_DEBOUNCE (8) /* 8 cycles CD debounce */
+
#define PAD_DELAY_MAX 32 /* PAD delay cells */
/*--------------------------------------------------------------------------*/
/* Descriptor Structure */
@@ -430,6 +432,7 @@ struct msdc_host {
bool hs400_cmd_resp_sel_rising;
/* cmd response sample selection for HS400 */
bool hs400_mode; /* current eMMC will run at hs400 mode */
+ bool internal_cd; /* Use internal card-detect logic */
struct msdc_save_para save_para; /* used when gate HCLK */
struct msdc_tune_para def_tune_para; /* default tune setting */
struct msdc_tune_para saved_tune_para; /* tune result of CMD21/CMD19 */
@@ -1430,6 +1433,11 @@ static irqreturn_t msdc_irq(int irq, void *dev_id)
sdio_signal_irq(host->mmc);
}

+ if ((events & event_mask) & MSDC_INT_CDSC) {
+ mmc_detect_change(host->mmc, msecs_to_jiffies(20));
+ events &= ~MSDC_INT_CDSC;
+ }
+
if (!(events & (event_mask & ~MSDC_INT_SDIOIRQ)))
break;

@@ -1463,14 +1471,24 @@ static void msdc_init_hw(struct msdc_host *host)
/* Reset */
msdc_reset_hw(host);

- /* Disable card detection */
- sdr_clr_bits(host->base + MSDC_PS, MSDC_PS_CDEN);
-
/* Disable and clear all interrupts */
writel(0, host->base + MSDC_INTEN);
val = readl(host->base + MSDC_INT);
writel(val, host->base + MSDC_INT);

+ /* Configure card detection */
+ if (host->internal_cd) {
+ sdr_set_field(host->base + MSDC_PS, MSDC_PS_CDDEBOUNCE,
+ DEFAULT_DEBOUNCE);
+ sdr_set_bits(host->base + MSDC_PS, MSDC_PS_CDEN);
+ sdr_set_bits(host->base + MSDC_INTEN, MSDC_INTEN_CDSC);
+ sdr_set_bits(host->base + SDC_CFG, SDC_CFG_INSWKUP);
+ } else {
+ sdr_clr_bits(host->base + SDC_CFG, SDC_CFG_INSWKUP);
+ sdr_clr_bits(host->base + MSDC_PS, MSDC_PS_CDEN);
+ sdr_clr_bits(host->base + MSDC_INTEN, MSDC_INTEN_CDSC);
+ }
+
if (host->top_base) {
writel(0, host->top_base + EMMC_TOP_CONTROL);
writel(0, host->top_base + EMMC_TOP_CMD);
@@ -1580,6 +1598,11 @@ static void msdc_init_hw(struct msdc_host *host)
static void msdc_deinit_hw(struct msdc_host *host)
{
u32 val;
+
+ /* Disabled card-detect */
+ sdr_clr_bits(host->base + MSDC_PS, MSDC_PS_CDEN);
+ sdr_clr_bits(host->base + SDC_CFG, SDC_CFG_INSWKUP);
+
/* Disable and clear all interrupts */
writel(0, host->base + MSDC_INTEN);

@@ -2078,13 +2101,31 @@ static void msdc_ack_sdio_irq(struct mmc_host *mmc)
__msdc_enable_sdio_irq(mmc, 1);
}

+static int msdc_get_cd(struct mmc_host *mmc)
+{
+ struct msdc_host *host = mmc_priv(mmc);
+ int val;
+
+ if (mmc->caps & MMC_CAP_NONREMOVABLE)
+ return 1;
+
+ if (!host->internal_cd)
+ return mmc_gpio_get_cd(mmc);
+
+ val = readl(host->base + MSDC_PS) & MSDC_PS_CDSTS;
+ if (mmc->caps2 & MMC_CAP2_CD_ACTIVE_HIGH)
+ return !!val;
+ else
+ return !val;
+}
+
static const struct mmc_host_ops mt_msdc_ops = {
.post_req = msdc_post_req,
.pre_req = msdc_pre_req,
.request = msdc_ops_request,
.set_ios = msdc_ops_set_ios,
.get_ro = mmc_gpio_get_ro,
- .get_cd = mmc_gpio_get_cd,
+ .get_cd = msdc_get_cd,
.enable_sdio_irq = msdc_enable_sdio_irq,
.ack_sdio_irq = msdc_ack_sdio_irq,
.start_signal_voltage_switch = msdc_ops_switch_volt,
@@ -2206,6 +2247,15 @@ static int msdc_drv_probe(struct platform_device *pdev)
goto host_free;
}

+ if (!(mmc->caps & MMC_CAP_NONREMOVABLE) &&
+ !mmc_can_gpio_cd(mmc)) {
+ /*
+ * Is removable but no GPIO declared, so
+ * use internal functionality.
+ */
+ host->internal_cd = true;
+ }
+
msdc_of_property_parse(pdev, host);

host->dev = &pdev->dev;