[PATCH 2/2] mmc: core: add reliable write setting to sysfs and update on read

[Marc Mattmueller <marc.mattmueller@xxxxxxxxxxxxx>]

The mmc reliable write setting (from ext_csd) was not available
on the sysfs.
Thus, added rel_param and rel_write_set to sysfs and added the
update of rel_write_set on sysfs read.

Signed-off-by: Marc Mattmueller <marc.mattmueller@xxxxxxxxxxxxx>
---
 drivers/mmc/core/mmc.c   | 29 +++++++++++++++++++++++++++++
 include/linux/mmc/card.h |  1 +
 include/linux/mmc/mmc.h  |  1 +
 3 files changed, 31 insertions(+)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index d9537c894e33..a64d1ecb0de9 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -364,6 +364,10 @@ static int mmc_update_ext_csd_runtime_params(struct mmc_card *card, u8 *ext_csd)
 {
 	int err = 0;
 
+	/* eMMC v4.41 or later */
+	if (card->ext_csd.rev >= 5)
+		card->ext_csd.rel_wr_set = ext_csd[EXT_CSD_WR_REL_SET];
+
 	/* eMMC v5 or later */
 	if (card->ext_csd.rev >= 7) {
 		card->ext_csd.pre_eol_info = ext_csd[EXT_CSD_PRE_EOL_INFO];
@@ -587,6 +591,7 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd)
 		}
 
 		card->ext_csd.rel_param = ext_csd[EXT_CSD_WR_REL_PARAM];
+		card->ext_csd.rel_wr_set = ext_csd[EXT_CSD_WR_REL_SET];
 		card->ext_csd.rst_n_function = ext_csd[EXT_CSD_RST_N_FUNCTION];
 
 		/*
@@ -820,6 +825,7 @@ MMC_DEV_ATTR(name, "%s\n", card->cid.prod_name);
 MMC_DEV_ATTR(oemid, "0x%04x\n", card->cid.oemid);
 MMC_DEV_ATTR(prv, "0x%x\n", card->cid.prv);
 MMC_DEV_ATTR(rev, "0x%x\n", card->ext_csd.rev);
+MMC_DEV_ATTR(rel_param, "0x%02x\n", card->ext_csd.rel_param);
 MMC_DEV_ATTR(serial, "0x%08x\n", card->cid.serial);
 MMC_DEV_ATTR(enhanced_area_offset, "%llu\n",
 		card->ext_csd.enhanced_area_offset);
@@ -886,6 +892,27 @@ static ssize_t pre_eol_info_show(struct device *dev,
 
 static DEVICE_ATTR_RO(pre_eol_info);
 
+static ssize_t rel_write_set_show(struct device *dev,
+				  struct device_attribute *attr,
+				  char *buf)
+{
+	int err = 0;
+	struct mmc_card *card = mmc_dev_to_card(dev);
+
+	/* before eMMC v4.41 */
+	if (card->ext_csd.rev < 5)
+		return sprintf(buf, "%s\n", "-");
+
+	/* eMMC v4.41 or later */
+	err = mmc_update_csd(card);
+	if (err)
+		return (ssize_t)err;
+
+	return sprintf(buf, "0x%02x\n", card->ext_csd.rel_wr_set);
+}
+
+static DEVICE_ATTR_RO(rel_write_set);
+
 static ssize_t mmc_fwrev_show(struct device *dev,
 			      struct device_attribute *attr,
 			      char *buf)
@@ -931,6 +958,8 @@ static struct attribute *mmc_std_attrs[] = {
 	&dev_attr_oemid.attr,
 	&dev_attr_prv.attr,
 	&dev_attr_rev.attr,
+	&dev_attr_rel_param.attr,
+	&dev_attr_rel_write_set.attr,
 	&dev_attr_pre_eol_info.attr,
 	&dev_attr_life_time.attr,
 	&dev_attr_serial.attr,
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 37f975875102..21c47893fcb4 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -48,6 +48,7 @@ struct mmc_ext_csd {
 	u8			sec_feature_support;
 	u8			rel_sectors;
 	u8			rel_param;
+	u8			rel_wr_set;
 	bool			enhanced_rpmb_supported;
 	u8			part_config;
 	u8			cache_ctrl;
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index d9a65c6a8816..42afd442a70a 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -266,6 +266,7 @@ static inline bool mmc_ready_for_data(u32 status)
 #define EXT_CSD_BKOPS_START		164	/* W */
 #define EXT_CSD_SANITIZE_START		165     /* W */
 #define EXT_CSD_WR_REL_PARAM		166	/* RO */
+#define EXT_CSD_WR_REL_SET		167	/* R/W */
 #define EXT_CSD_RPMB_MULT		168	/* RO */
 #define EXT_CSD_FW_CONFIG		169	/* R/W */
 #define EXT_CSD_BOOT_WP			173	/* R/W */
-- 
2.20.1