[PATCH 5/5] mmc: mtk-sd: enable internal write-protect logic.

From: NeilBrown
Date: Tue Apr 16 2019 - 00:48:40 EST


The mtk-sd silicon has integrated write-protect detection logic.

If the sdhci isn't marked no-write-protect and doesn't have a
ro-gpio configured, assume the internal wp logic should be used.

Signed-off-by: NeilBrown <neil@xxxxxxxxxx>
---
drivers/mmc/host/mtk-sd.c | 30 +++++++++++++++++++++++++++++-
1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 341cf5f03429..d63d6b62f49a 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -433,6 +433,7 @@ struct msdc_host {
/* cmd response sample selection for HS400 */
bool hs400_mode; /* current eMMC will run at hs400 mode */
bool internal_cd; /* Use internal card-detect logic */
+ bool internal_ro; /* Use internal write-protect 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 */
@@ -2119,12 +2120,30 @@ static int msdc_get_cd(struct mmc_host *mmc)
return !val;
}

+static int msdc_get_ro(struct mmc_host *mmc)
+{
+ struct msdc_host *host = mmc_priv(mmc);
+ int val;
+
+ if (mmc->caps2 & MMC_CAP2_NO_WRITE_PROTECT)
+ return 0;
+
+ if (!host->internal_ro)
+ return mmc_gpio_get_ro(mmc);
+
+ val = readl(host->base + MSDC_PS) & MSDC_PS_WP;
+ if (mmc->caps2 & MMC_CAP2_RO_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_ro = msdc_get_ro,
.get_cd = msdc_get_cd,
.enable_sdio_irq = msdc_enable_sdio_irq,
.ack_sdio_irq = msdc_ack_sdio_irq,
@@ -2256,6 +2275,15 @@ static int msdc_drv_probe(struct platform_device *pdev)
host->internal_cd = true;
}

+ if (!(mmc->caps2 & MMC_CAP2_NO_WRITE_PROTECT) &&
+ !mmc_can_gpio_ro(mmc)) {
+ /*
+ * Has write-protect but no GPIO declared, so
+ * use internal functionality.
+ */
+ host->internal_ro = true;
+ }
+
msdc_of_property_parse(pdev, host);

host->dev = &pdev->dev;